JP7798536B2 - Compressor system, compressor control device, and compressor control method - Google Patents

Description

The present invention relates to a compressor system, a compressor control device, and a compressor control method.

Compressor systems that generate compressed gas are constructed using multiple compressors. In such compressor systems, the discharge piping systems of the multiple compressors are merged into one to discharge the compressed gas, and the number of compressors that are operating and stopped is controlled to change depending on the usage status of the compressed gas.

Compressors are typically equipped with an intake filter to ensure the quality of the discharge air and for equipment maintenance. For example, in the case of a packaged compressor in which the compressor main unit is housed within a housing, the housing has an opening that allows air to be taken in from the outside, filtered to remove dust and debris, via the intake filter. In addition, for example, in both packaged compressors and compressors without a housing in which the compressor unit is exposed to the outside, an intake filter is attached to the intake section of the compressor main unit.

A clogged intake filter causes a loss of suction pressure, resulting in a decrease in the amount of discharged air and power loss, which reduces the compressor's power efficiency. Therefore, it is recommended that the intake filter be cleaned or replaced regularly, but compressor users sometimes forget to do this.

In response to this, Patent Document 1 discloses a technology that notifies users when it is time to replace an intake filter. Specifically, Patent Document 1 discloses a package-type compressor that includes a filter placed at the intake port of the compressor housing, a pressure detector placed near the intake port on the inside of the housing, and an external device. When the pressure detected by the pressure detector is below a predetermined pressure, the external device is fired to notify the user that the filter is clogged (i.e., to notify the user that replacement or cleaning is required).

International Publication No. 2019/082552

However, while the above-mentioned conventional technology can alert users to the need to clean or replace the intake filter, if the user forgets to clean or replace it despite receiving the alert, power loss due to increased suction pressure loss will continue. Furthermore, alerts for replacement, etc. are issued when the suction pressure is below a predetermined pressure, but because a certain amount of clogging is tolerated until just before the pressure drops below the predetermined pressure, this generates a corresponding power loss and can potentially reduce the compressor's power efficiency. To solve this problem, if the predetermined pressure value that triggers the alert is set lower, the alert cycle would become shorter, resulting in more frequent alerts and potential problems.

The present invention was made in consideration of the above points, and one of its objectives is to suppress a decrease in the power efficiency of the entire compressor system when operating a compressor system consisting of multiple compressors, depending on the status of each compressor's filter, such as clogging.

To solve this problem, the present invention provides a compressor system having multiple compressors and a compressor control device that controls the operation of the multiple compressors, each of which has a filter that filters air, a compressor main body that compresses the air, and a detection means that detects a physical quantity that is correlated with the pressure loss of the compressor main body, and the compressor control device is characterized in that it prioritizes the operation of a compressor among the multiple compressors that has a higher power efficiency according to the physical quantity detected by the detection means, and restricts the operation of compressors with a lower power efficiency.

According to the present invention, for example, when operating a compressor system comprising multiple compressors, it is possible to suppress a decrease in the power efficiency of the entire compressor system depending on the status of each compressor's filter, such as clogging.

1 is a configuration diagram of a compressor system according to a first embodiment. FIG. 1 is a configuration diagram of a compressor (constant speed compressor) according to a first embodiment. FIG. 1 is a configuration diagram of a compressor (variable speed compressor) according to a first embodiment. FIG. 1 is a configuration diagram of a compressor control device according to a first embodiment. FIG. FIG. 4 is a diagram illustrating a configuration of a pressure loss information table according to the first embodiment. FIG. 4 is a diagram showing the configuration of a pressure loss determination table according to the first embodiment. FIG. 3 is a configuration diagram of an operation period allocation table according to the first embodiment. FIG. 3 is a diagram illustrating the configuration of an operation pattern table according to the first embodiment. 10 is a flowchart showing a process for generating pressure loss information and operating period allocation information according to the first embodiment. 4 is a flowchart showing a driving pattern information generation process according to the first embodiment. 10 is an explanatory diagram of generation of driving pattern information (driving pattern table) according to application example 1 of embodiment 1 (when a total of four machines, including two constant speed machines and two variable speed machines, are operating normally). FIG. 10 is an explanatory diagram of generation of operation pattern information (operation pattern table) according to application example 1 of embodiment 1 (when compression loss occurs in a variable speed machine). FIG. FIG. 10 is an explanatory diagram of generation of operation pattern information (operation pattern table) according to application example 1 of embodiment 1 (when compression loss occurs in a constant speed machine). 10 is an explanatory diagram of generation of driving pattern information (driving pattern table) according to application example 2 of embodiment 1 (when a total of three machines, including two constant speed machines and one variable speed machine, are operating normally). FIG. 10 is an explanatory diagram of generation of operation pattern information (operation pattern table) according to application example 2 of embodiment 1 (when compression loss occurs in a variable speed machine). FIG. FIG. 10 is an explanatory diagram of generation of operation pattern information (operation pattern table) according to application example 2 of embodiment 1 (when compression loss occurs in a constant speed machine). FIG. 3 is an explanatory diagram of a display screen in the compressor control device according to the first embodiment. 10 is a flowchart showing a driving pattern information generation process according to a second embodiment. 20 is a detailed flow of step S24 of the driving pattern information generation process of FIG. 18. 19 is a detailed flow of step S25 of the driving pattern information generation process of FIG. 18. 20 is a detailed flow of step S26 of the driving pattern information generation process of FIG. 18. 19 is a detailed flow of step S27 of the driving pattern information generation process of FIG. 18. 20 is a detailed flow of step S28 of the driving pattern information generation process of FIG. 18. 19 is a detailed flow of step S29 of the driving pattern information generation process of FIG. 18.

Embodiments and examples of the present invention are described in detail below with reference to the drawings. The embodiments and examples of the present invention disclose a compressor system comprising one or more compressors (constant speed compressors) that produce compressed air by rotating the compressor body under constant speed control, and one or more compressors (variable speed compressors) that produce compressed air by rotating the compressor body under variable speed control, such as with an inverter. In this compressor system, the constant speed compressor and variable speed compressor are appropriately assigned between full load operation and capacity control operation depending on the pressure loss (hereinafter referred to as "pressure loss") of intake filters, separator elements, etc., and the compressor system as a whole produces and supplies compressed air to compressed air consumers connected to a piping network with better power efficiency.

In the following drawings used to explain the embodiments and examples, the same reference numbers will indicate configurations or processes with the same or similar functions, and subsequent explanations will be omitted. Furthermore, the various embodiments and examples can be combined in whole or in part within the scope and consistency of the technical concept of the present invention. Furthermore, in the following embodiments and examples, explanations of previously mentioned configurations and processes will be omitted, and explanations will focus on the differences.

In the following explanation, expressions such as "xxx table" may be used to describe information that produces output in response to input, but this information can be data of any structure. Therefore, "xxx table" can also be called "xxx information."

Furthermore, in the following description, the configuration of each table is an example, and one table may be divided into two or more tables, or all or part of two or more tables may be combined into one table.

[Embodiment 1]
<Configuration of compressor system 1 according to embodiment 1>
FIG. 1 is a configuration diagram of a compressor system 1 according to an embodiment. The compressor system 1 includes M compressors (constant speed compressors F1, F2, ..., FM) and N compressors (variable speed compressors V1, V2, ..., VN). M and N are natural numbers including 0. M = 0 means that there is no constant speed compressor, and N = 0 means that there is no variable speed compressor. The constant speed compressors Fi (i = 1, 2, ..., M) and variable speed compressors Vj (j = 1, 2, ..., N) are collectively referred to as compressors 4.

The constant speed machine Fi controls the compressor body between load (production of compressed air) and unload (standby with empty operation) to perform constant speed control to produce compressed air. The variable speed machines Vj each have an inverter and PID (Proportional-Integral-Differential) function, and perform variable speed control to produce compressed air by changing the rotation speed.

The compressed air outlets of the constant speed machine Fi and the variable speed machine Vj are combined and connected to an air tank (tank) 5. The compressed air produced by the constant speed machine Fi and the variable speed machine Vj is supplied to the compressed air usage line via the air tank 5.

A pressure sensor 6 is attached to the air tank 5, and the measurement signal from the pressure sensor 6 measuring the pressure inside the air tank 5 is input into the management device 2. The management device 2 is a cloud-based device that collects measurement information from the compressor system 1, such as the measurement signal from the pressure sensor 6 and the measurement signals from the constant speed unit Fi and variable speed unit Vj sensors, and provides displays based on the various measurement information to the user and outputs various alerts. The management device 2 outputs various measurement information from the compressor system 1 to the compressor control device 3. Note that the management device 2 may be an on-premise device along with the compressor control device 3.

The compressor control device 3 is an on-premise device. Based on various measurement information of the compressor system 1 notified by the management device 2, the compressor control device 3 determines the operation and operation restrictions of the constant speed unit Fi and the variable speed unit Vj according to the air usage ratio of the compressed air produced by the compressor system 1. The compressor control device 3 creates an operation pattern table 31d (Figure 8, also referred to as "operation pattern information") described below based on the operation and operation restrictions determined. The compressor control device 3 may also be a cloud-based device together with the management device 2.

<Configuration of Compressor (Constant Speed) Fi>
2 is a configuration diagram of a compressor (constant speed compressor) Fi according to the first embodiment. The main body and the like of the constant speed compressor Fi are housed in a housing 41. The peripheral surface of the housing 41 is provided with an outside air inlet 42 for taking in outside air and an exhaust port 43 for discharging air from inside the housing 41 to the outside. Part of the air drawn in from outside the housing 41 by the rotation of the fan 44 flows into the intake section of the compressor main body 45 and becomes compressed air, and part of the air cools the compressor main body 45 and other auxiliaries before being discharged to the outside from the exhaust port 43.

An outside air filter 46 is installed at the outside air inlet 42 of the housing 41 as a dust collection member. In addition, an intake filter 47 is also located upstream of the intake section of the compressor main body 45. Dust is removed from the air flowing into the housing 41 from the outside air inlet 42 by the outside air filter 46. Dust is removed from the air drawn into the compressor main body 45 from the intake section of the compressor main body 45 by the intake filter 47.

A pressure sensor 48 is located near the outside air inlet 42. The pressure sensor 48 detects the degree of negative pressure caused by the intake of air.

The control unit 49F has an arithmetic control unit (e.g., a CPU (Central Processing Unit)) that executes arithmetic processing and control processing based on a program, and a memory unit (e.g., a ROM (Read Only Memory), RAM (Random Access Memory)) that stores the programs and the results of arithmetic processing. The control unit 49F controls the electromagnetic contactor 50F based on operation commands received from the compressor control device 3, drives and stops the motor 51, and operates the constant speed unit Fi in capacity control operation or full load operation. In capacity control operation of the constant speed unit Fi, the amount of compressed air produced is increased or decreased by adjusting and repeating periods of loading and unloading at a constant rotation speed. In full load operation of the constant speed unit Fi, the amount of compressed air produced is kept constant by regularly repeating periods of loading and unloading at a constant rotation speed.

The control unit 49F also transmits the suction pressure detected by the pressure sensor 48 to the management device 2.

The motor 51 is connected to the commercial power supply 52 via the electromagnetic contactor 50F. When the pressure in the air tank 5 detected by the pressure sensor 6 rises to the operating pressure, the control unit 49F opens the contacts of the electromagnetic contactor 50F to stop the motor 51 and stop the supply of compressed air from the compressor main body 45 to the air tank 5 (unload). Furthermore, when the pressure in the air tank 5 detected by the pressure sensor 6 drops to the return pressure, the control unit 49F closes the contacts of the electromagnetic contactor 50F to drive the motor 51 and restore the supply of compressed air from the compressor main body 45 to the air tank 5 (load).

The compressor body 45 is, for example, a reciprocating compressor, and has a cylinder, piston, suction valve, and discharge valve. The rotational motion of the motor 51 is transmitted via pulleys and belts, and is further converted into reciprocating motion via a crankshaft or other mechanism and transmitted to the piston. This causes the piston in the cylinder to reciprocate, changing the volume of the working chamber within the cylinder. The suction valve opens, the discharge valve closes, and the volume of the working chamber increases, drawing air into the working chamber (suction process). Then, the suction valve closes, and the discharge valve closes, decreasing the volume of the working chamber, compressing the air in the working chamber (compression process). Then, the suction valve closes, and the discharge valve opens, discharging compressed air from the working chamber (discharge process).

Constant speed machines Fi generally have better power efficiency during full load operation (operation at 100% load) than variable speed machines Vj.

<Configuration of Compressor (Variable Speed Machine Vj)>
3 is a configuration diagram of a compressor (variable speed compressor Vj) according to embodiment 1. Compared to the constant speed compressor Vi, the variable speed compressor Vj includes a control unit 49V instead of the control unit 49F and an inverter 50V instead of the electromagnetic contactor 50F. Otherwise, the variable speed compressor Vj is the same as the constant speed compressor Vi.

The control unit 49V has an arithmetic control unit (e.g., a CPU) that executes arithmetic processing and control processing based on a program, and a memory unit (e.g., a ROM or RAM) that stores the programs and the results of arithmetic processing. The control unit 49V controls the inverter 50V to drive the motor 51 based on the operation command received from the compressor control device 3, and causes the variable speed machine Vj to operate in capacity control mode or full load mode. In capacity control mode, the rotation speed of the motor 51 is adjusted to follow the target pressure in the air tank 5, thereby increasing or decreasing the amount of compressed air produced. In full load mode, the rotation speed of the motor 51 is set to full load, maintaining a constant maximum amount of compressed air produced.

The control unit 49V also transmits the suction pressure detected by the pressure sensor 48 to the management device 2.

The control unit 49F controls the rotation of the inverter 50V and adjusts the amount of compressed air supplied from the compressor main body 45 to the air tank 5 so that the pressure in the air tank 5 detected by the pressure sensor 6 falls within the fluctuation range of the target pressure.

Variable speed machines Vj generally have better power efficiency during capacity control operation (operation with varying load) than fixed speed machines Vi.

<Configuration of compressor control device 3 of embodiment 1>
4 is a configuration diagram of the compressor control device 3 according to the embodiment 1. The compressor control device 3 includes a storage 31, a processor 32, a memory 33, and a peripheral device 34.

Storage 31 is a storage device with a specified storage area, and stores a pressure loss information table 31a, a pressure loss determination table 31b, an operating period allocation table 31c, and an operating pattern table 31d.

The processor 32 includes one or more processors, and may be, for example, a microprocessor such as a CPU, but may also be other types of processors such as a GPU (Graphics Processing Unit). The processor may also be single-core or multi-core. The processor may also be a broader processor, such as a hardware circuit that performs some or all of the processing (for example, an FPGA (Field-Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit)).

The processor 32 executes programs read from a predetermined memory area such as the storage 31 in cooperation with the memory 33, thereby realizing the information generation unit 32a, the driving pattern information generation unit 32b, and the driving control unit 32c.

The information generation unit 32a generates the pressure loss information table 31a and the operation period allocation table 31c. The operation pattern information generation unit 32b generates the operation pattern table 31d. The processing of the information generation unit 32a and the operation pattern information generation unit 32b will be described later with reference to Figure 9.

The operation control unit 32c outputs operation and operation restriction commands (such as reducing the operation period or restricting the rotational speed) to the constant speed machine Fi and the variable speed machine Vj in accordance with the information in the operation pattern table 31d generated by the operation pattern information generation unit 32b.

The peripheral devices 34 include devices such as a communication interface that enables the compressor control device 3 to communicate with the management device 2, the constant speed unit Fi, and the variable speed unit Vj, an output device such as a display that outputs information, and an input device that accepts information input.

The pressure loss information table 31a, pressure loss determination table 31b, operation period allocation table 31c, operation pattern table 31d, information generator 32a, and operation pattern information generator 32b of the compressor control device 3 may be provided on a cloud server. In this case, the operation controller 32c of the compressor control device 3 controls the operation of each compressor 4 in response to operation instructions based on the operation pattern table 31d created on the cloud server.

<Configuration of Pressure Loss Information Table 31a in First Embodiment>
5 is a diagram showing the configuration of the pressure loss information table 31a according to the first embodiment. The pressure loss information table 31a records the "presence or absence of pressure loss" for each compressor 4 of the constant speed compressor Fi and the variable speed compressor Fj. The "presence or absence of pressure loss" is determined based on the suction pressure detected by the pressure sensor 48 of each compressor, which is periodically collected, and the pressure loss determination table 31b.

For example, if "Presence or absence of pressure loss" is "0", there is no pressure loss in the corresponding compressor 4. If "Presence or absence of pressure loss" is "1", there is a pressure loss in the corresponding compressor 4.

<Configuration of pressure loss determination table 31b in embodiment 1>
6 is a configuration diagram of the pressure loss determination table 31b according to the first embodiment. The pressure loss determination table 31b stores reference information for determining whether the suction pressure detected by the pressure sensor 48 of each compressor 4 is "normal" or "pressure loss occurs." For example, when the "suction pressure P" satisfies "P1≦P" (P1 is a predetermined value), it is determined that the corresponding compressor 4 has a "pressure loss Q" of "Q1≦Q" (Q1 is a predetermined value).

If there is a pressure loss, the operation of the corresponding compressor 4 is restricted. For example, if the "suction pressure P" is "P1≦P," the operating period of the corresponding compressor in the operating period allocation table 31c described below is "reduced by 2/3" from the default information (reduced operating period), as shown in "Degenerate," and the reduced mass is allocated to other compressors. "Mas" refers to the area in the operating pattern table 31d that represents the power consumption characteristics of each compressor 4 that constitutes the compressor system 1, after the power consumption characteristics of the entire compressor system 1 are broken down into individual compressors 4. Default information refers to information in the operating period allocation table 31c in which mass is evenly allocated to each compressor 4 when no pressure loss occurs in any of the compressors 4,

From an energy conservation perspective, it is desirable to allocate the mass removed from a compressor 4 due to compression loss to a compressor 4 that has the same performance (constant speed or variable speed) as the compressor 4 whose mass has been removed and that is not experiencing compression loss.

However, it is not always possible to allocate all of the reduced mass to compressors 4 that have the same performance as the compressors 4 that have reduced mass due to degeneration caused by compression losses and that do not experience compression losses. In this case, it may be necessary to allocate the reduced mass to compressors 4 with different performance, or to operate compressors 4 with compression losses. Therefore, the mass allocation method is selected to improve or optimize the power efficiency of the entire compressor system 1, taking into account the power efficiency minus the compression losses of each compressor 4.

In the pressure loss determination table 31b, suction pressure abnormalities detected by the pressure sensor 48 of each compressor 4 are not classified into a single level of "pressure loss present," but this is not limiting and two or more levels may be used depending on the degree of suction pressure abnormality. When classified into two or more levels, the higher the degree (level) of pressure loss abnormality, the greater the restriction on operation of the corresponding compressor 4.

Furthermore, operational restrictions on compressor 4 include stopping operation and degeneration. Degeneration is not limited to the "reduced operating period" described above, but may also involve operation within a rotational speed range (e.g., low speed range) that does not reduce power efficiency.

In this embodiment, the pressure loss is assumed to be a suction pressure loss due to clogging of the fresh air filter 46 of the fresh air inlet 42, and the occurrence of this compression loss is detected based on the suction pressure of the fresh air filter 46. However, this is not limited to this. For example, the pressure loss may be assumed to be a suction pressure loss due to clogging of the intake filter 47 of the intake section of the compressor main body 45, and the occurrence of this pressure loss may be detected based on the temperature around the intake filter 47 of the compressor main body 45 or the intake section. Alternatively, the compression loss may be assumed to be a pressure loss due to clogging of the separator element that filters the compressed air discharged from the compressor main body 45 and removes lubricating oil from the compressor main body 45, and the occurrence of this pressure loss may be detected based on the value obtained by subtracting the discharge pressure of the compressed air from the compressor main body 45 from the pressure in the air tank 5 detected by the pressure sensor 6. In other words, the occurrence of compression loss in the compressor 4 may be detected based on at least one physical quantity that is correlated with compression loss, such as the suction pressure or temperature of the filter.

<Configuration of operation period allocation table 31c>
FIG. 7 is a configuration diagram of an operating period allocation table 31c according to the first embodiment. The operating period allocation table 31c records the number of squares reserved for each compressor 4, representing the operating period for operating each compressor 4, in an operation pattern table 31d (FIG. 8) described below. For example, a "constant speed compressor" with "compressor" F1 is assigned an "operating period (number of squares)" of "a1". If no compression loss occurs in any compressor, each compressor 4 is assigned the same number "{(M+N) ²⁺ (M+N)}/(M+N)" = "M+N+1". If a compression loss occurs in the compressor 4, the "operating period (number of squares)" for each compressor 4 is reduced, and the "operating period (number of squares)" is allocated to the "operating period (number of squares)" of the other compressors 4.

<Configuration of operation pattern table 31d>
8 is a configuration diagram of the operation pattern table 31d according to embodiment 1. The operation pattern table 31d is created by accumulating designations of the compressors 4 to be operated and the power consumption characteristics of the constant speed and variable speed compressors 4 in order to derive a target operating air compression ratio.

In the operation pattern table 31d, the horizontal axis represents the air consumption ratio (%) and the vertical axis represents the power consumption ratio (%). Figure 8 shows the case of a total of M constant speed machines and N variable speed machines (M+N), with the horizontal axis taking values of 0-100-200-300..... (M+N) x 100..... 300-200-100 and the vertical axis taking values of 0-100-200-300..... (M+N) x 100.

In the graph of Figure 8, the region where the power consumption characteristics are roughly represented by the diagonal lines of the boxes is called the capacity adjustment region. In the capacity adjustment region, the compressor 4 operates under capacity control. Also, in the graph of Figure 8, the region where the entire box is filled in is called the full load region. In the full load region, the compressor 4 operates under full load. Generally, variable speed machines have better power consumption characteristics than constant speed machines during capacity control operation in the capacity adjustment region, and constant speed machines have better power consumption characteristics than variable speed machines during full load operation in the full load region.

In FIG. 8, since no compression loss occurs in any of the compressors, the same number of squares, "{(M+N) ² +(M+N)}/(M+N)," is evenly allocated to each compressor 4, so that each compressor 4 operates for an equal period of time.

For example, if the air usage ratio of the entire compressor system 1 is between 100 and 200, the target air usage ratio can be achieved by operating the constant speed machine F1 at a full load and constant speed, and operating the variable speed machine V1 at a variable speed. When the air usage ratio shifts from 100-200 to 200-300, the target air usage ratio can be achieved by operating the constant speed machine F2 at a full load and constant speed, in addition to operating the constant speed machine F1 at a full load and constant speed, and operating the variable speed machine V1 at a variable speed.

Furthermore, when the air usage ratio is between 300 and 200, the target air usage ratio can be achieved by operating the constant speed machines F1 and F2 at a constant speed under full load and operating the variable speed machine VN at a variable speed. When the air usage ratio shifts from 300-200 to 200-100, the constant speed machine F1 is stopped, the constant speed machine F2 is operated at a constant speed under full load, and the variable speed machine VN is operated at a variable speed, thereby achieving the target air usage ratio.

<Pressure loss information and operating period allocation information generation process>
9 is a flowchart showing a process for generating pressure loss information and operating period allocation information according to the first embodiment. The process for generating pressure loss information and operating period allocation information is executed repeatedly at a predetermined cycle by the information generating unit 32a of the compressor control device 3, or is executed in response to a user instruction. The pressure loss information is information recorded in the pressure loss information table 31a. The operating period allocation information is information recorded in the operating period allocation table 31c.

First, in step S11, the information generation unit 32a determines whether or not pressure loss has occurred in each compressor 4. Next, in step S12, the information generation unit 32a generates pressure loss information from the results of the determination of whether or not pressure loss has occurred in step S11. Specifically, the information generation unit 32a references the pressure loss determination table 31b based on the pressure measured by the pressure sensor 48, determines whether or not there is suction pressure loss due to the outside air filter 46 of the outside air inlet 42, and sets a pressure loss flag in the "Presence or absence of pressure loss" column for the compressor 4 for which it is determined that pressure loss has occurred.

Next, in step S13, the information generation unit 32a generates operating period allocation information based on the pressure loss information generated in step S12. Specifically, the information generation unit 32a references the pressure loss information and performs degeneration ("reduce the mass by 2/3" of "degeneration" in the pressure loss determination table 31b) according to the pressure loss for the operation of the compressor 4 experiencing pressure loss on the "operating period" of the corresponding compressor 4 in the operating period allocation table 31c. In other words, degenerate operation is performed to shorten the operating period of the compressor 4 according to the pressure loss. The information generation unit 32a allocates the operating period reduced from the corresponding compressor 4 by degeneration from the operating period allocation table 31c to the operating periods of the other compressors 4.

<Driving pattern information generation process>
10 is a flowchart showing an operation pattern information generation process according to the first embodiment. The operation pattern information generation process is repeatedly executed at a predetermined cycle by the operation pattern information generation unit 32b of the compressor control device 3, or is executed in response to a user instruction. The operation pattern information is information recorded in the operation pattern table 31d.

First, in step S20, the driving pattern information generation unit 32b determines whether the pressure loss information (pressure loss information table 31a) has changed since the previous execution of the driving pattern information generation process. The pressure loss information is saved in a predetermined storage area each time the driving pattern information generation process is executed. If the pressure loss information has changed (step S20 YES), the driving pattern information generation unit 32b proceeds to step S21, and if the pressure loss information has not changed (step S20 NO), the driving pattern information generation process ends.

In step S21, the operation pattern information generation unit 32b reduces the "operating period (number of squares)" for each compressor 4 in accordance with the compression loss if a compression loss has occurred in that compressor 4, and allocates the reduced squares to the "operating periods (number of squares)" of the other compressors 4.

Next, in step S33, if the changed operation pattern information newly created in the processing of step S21 is more energy-efficient than the operation pattern information before the change, the operation pattern information generation unit 32b updates the pressure loss information table 31a with the changed operation pattern information. The energy of the operation pattern information before and after the change is calculated by integrating the power consumption characteristics when each compressor 4 (constant speed unit Fi and variable speed unit Vj) is operated at full load and under capacity control in accordance with the operation pattern. At this time, the decrease in rated power efficiency due to compression loss of each compressor 4 is taken into account. On the other hand, if the changed operation pattern information is more energy-efficient than the operation pattern information before the change, the operation pattern information generation unit 32b discards the changed operation pattern and maintains the operation pattern information before the change.

<Application Example 1>
Hereinafter, an example in which the compressor system 1 is configured with a total of four compressors (M=N=2), including two constant speed compressors and two variable speed compressors, will be described as Application Example 1 of Embodiment 1.

Figure 11 is an explanatory diagram of the generation of operation pattern information (operation pattern table 31d) for application example 1 of embodiment 1 (when a total of four compressors, two constant speed compressors and two variable speed compressors, are operating normally). As shown in Figure 11 (a), no compression loss occurs in any of the four compressors 4 that make up the compressor system 1.

As a result, the operating period (number of cells) is allocated equally between the two constant speed machines in total and the two variable speed machines in total, at 20/2 = 10, and is also allocated equally within each of the constant speed machines and the variable speed machines, at 10/2 = 5. This results in an operating period allocation table 31c as shown in Figure 11(b). Based on the operating period allocation table 31c shown in Figure 11(b), an operating pattern table 31d may be, for example, as shown in Figure 11(c). The operating pattern table 31d in Figure 11(c) is created as default information before the compressor system 1 is put into operation.

Next, we will explain what happens when pressure loss occurs in the variable speed drive V1 in Application Example 1. Figure 12 is an explanatory diagram of the generation of operating pattern information (operating pattern table 31d) for Application Example 1 of Embodiment 1 (when compression loss occurs in the variable speed drive).

As shown in Figure 12(a), assume that compression loss occurs in variable speed unit V1, one of the four compressors 4 that make up compressor system 1. In this case, the operating period of variable speed unit V1 is degenerated to "reduced by 2/3." The operating period allocation to each compressor 4 other than variable speed unit V1 is then rebalanced, and the degenerated amount of variable speed unit V1, "5 x (2/3) = 3 units," is allocated to variable speed unit V2. Therefore, operating period allocation table 31c becomes as shown in Figure 12(b). Furthermore, based on operating period allocation table 31c shown in Figure 12(b), variable speed unit V2 in the capacity adjustment ranges where the air usage ratio is 0 to 100, 100 to 200, and 200 to 300 (%) is replaced with variable speed unit V2, and the operating pattern table 31d is updated, for example, as shown in Figure 12(c).

In the operation pattern table 31d shown in (c) of each of Figures 11 and 12, the variable speed units V1 and V2 are swapped when the air consumption ratio is 300-400 and 400-300% and the power consumption ratio is 200-300 and 300-400%. This is the case when the operation pattern table 31d is updated to optimize the power efficiency of the entire compressor system 1, taking into account the decrease in rated power efficiency due to the compression loss of the variable speed unit V1. However, even if the variable speed units V1 and V2 are not swapped in (c) of Figure 12 and are kept the same as in (c) of Figure 11, the objective of improving the power efficiency of the entire compressor system 1 can be achieved, taking into account the decrease in rated power efficiency due to the compression loss of the variable speed unit V1.

Next, we will explain what happens when pressure loss occurs in the constant speed machine F2 in Application Example 1. Figure 13 is an explanatory diagram of the generation of operation pattern information (operation pattern table 31d) for Application Example 1 of Embodiment 1 (when compression loss occurs in the constant speed machine).

As shown in (a) of Figure 13, assume that compression loss occurs in constant speed compressor F2, one of the four compressors 4 that make up compressor system 1. In this case, the operating period of constant speed compressor F2 is degenerated to "reduced by 2/3." The operating period allocation of each compressor 4 other than constant speed compressor F2 is then rebalanced, and the degenerated amount of constant speed compressor F1, "5 x (2/3) = 3 units," is allocated evenly to the other constant speed compressors and variable speed compressors. Therefore, the operating period allocation table 31c becomes as shown in (b) of Figure 19. Furthermore, based on the operating period allocation table 31c shown in Figure 19(b), the operating pattern table 31d replaces the constant speed machine F2 in the full load range where the air usage ratio is 200 to 300% with the variable speed machine V1, and the variable speed machine V1 in the capacity adjustment range with the variable speed machine V2. Also, the constant speed machine F2 in the full load range where the air usage ratio is 300 to 200% with the variable speed machine V1, and the constant speed machine F2 in the full load range where the air usage ratio is 200 to 100% with the constant speed machine F1. Therefore, for example, it becomes as shown in Figure 13(c).

<Application Example 2>
Next, an example in which the compressor system 1 is configured with a total of three compressors (M=2, N=1), including two constant speed compressors and one variable speed compressor, will be described as Application Example 2 of Embodiment 1.

Figure 14 is an explanatory diagram of the generation of operation pattern information (operation pattern table 31d) according to application example 2 of embodiment 1 (when a total of three compressors, two constant speed compressors and one variable speed compressor, are operating normally). As shown in Figure 14 (a), no compression loss occurs in any of the three compressors 4 that make up the compressor system 1.

As a result, the operating period (number of cells) is allocated equally between the two constant speed machines combined and the one variable speed machine, at 12/2 = 6, and is also allocated equally within each of the constant speed machines and the variable speed machine, resulting in an operating period allocation table 31c as shown in Figure 14(b). Based on the operating period allocation table 31c shown in Figure 14(b), an operating pattern table 31d may be as shown in Figure 14(c), for example. The operating pattern table 31d in Figure 14(c) is created as default information before the compressor system 1 is put into operation.

Next, we will explain what happens when pressure loss occurs in the variable speed drive V1 in Application Example 2 of Embodiment 1. Figure 15 is an explanatory diagram of the generation of operating pattern information (operating pattern table 31d) for Application Example 2 of Embodiment 1 (when compression loss occurs in the variable speed drive).

As shown in Figure 15(a), assume that a compression loss occurs in variable speed unit V1, one of the three compressors 4 that make up compressor system 1. In this case, the operating period of variable speed unit V1 is degenerated to "reduced by 2/3." The operating period allocation to each compressor 4 other than variable speed unit V1 is then rebalanced, and the degenerated amount for variable speed unit V1, "6 x (2/3) = 4 units," is evenly allocated to all other constant speed units. Therefore, the operating period allocation table 31c becomes as shown in Figure 15(b).

Furthermore, based on the operating period allocation table 31c shown in Figure 15(b), the operating pattern table 31d replaces the variable speed machine V1 in the capacity adjustment ranges of 0 to 100 and 100 to 200 (%) with the constant speed machines F1 and F2, respectively, and also replaces the variable speed machine V1 in the capacity adjustment ranges of 200 to 100 and 100 to 0 (%) with the constant speed machines F1 and F2, respectively. Therefore, for example, it becomes as shown in Figure 15(c).

Next, we will explain what happens when pressure loss occurs in the constant speed machine F2 in Application Example 2. Figure 16 is an explanatory diagram of how operation pattern information (operation pattern table 31d) is generated for Application Example 2 (when compression loss occurs in the constant speed machine).

As shown in Figure 16(a), assume that a compression loss occurs in constant speed compressor F2, one of the three compressors 4 that make up compressor system 1. In this case, the operating period of constant speed compressor F2 is reduced to "reduced by 2/3." The operating period allocation of each compressor 4 other than constant speed compressor F2 is then rebalanced, and the reduced amount of constant speed compressor F1, "3 x (2/3) = 2 units," is evenly allocated to the other constant speed compressors. Therefore, the operating period allocation table 31c becomes as shown in Figure 16(b).

Furthermore, based on the operating period allocation table 31c shown in Figure 16(b), the operating pattern table 31d replaces the constant speed machine F2 in the full load range where the air usage ratio is 200 to 100% with the constant speed machine F1, resulting in, for example, the table shown in Figure 16(c).

<Display of driving pattern information, etc. to the user>
Fig. 17 is an explanatory diagram of a display screen 34a in the compressor control device 3 according to the first embodiment. As shown in Fig. 17, the compressor control device 3 outputs a display screen 34a from an output device that indicates changes from the default information in the operation pattern table 31d (operation pattern information) such as those shown in Figs. 11 to 16, thereby enabling the user to intuitively understand which compressor 4 has generated pressure loss and which compressor 4 will be substituted. Furthermore, as shown in Fig. 17, the compressor control device 3 can also notify the user to perform maintenance by indicating the filter that is causing pressure loss in the compressor 4 that is not operating.

The display screen 34a may be output from the output device of the management device 2, rather than the compressor control device 3.

[Embodiment 2]
In the second embodiment, the compressor control device 3 is different in the operation pattern information generation process executed by the operation pattern information generation unit 32b, but is otherwise similar.

<Driving pattern generation process of the second embodiment>
18 is a flowchart showing an operation pattern information generation process according to the second embodiment. The operation pattern information generation process according to the second embodiment is repeatedly executed at a predetermined cycle by the operation pattern information generation unit 32b of the compressor control device 3, or is executed in response to a user instruction. The operation pattern information is information recorded in the operation pattern table 31d.

First, in step S20, the driving pattern information generation unit 32b determines whether the pressure loss information (pressure loss information table 31a) has changed since the previous execution of the driving pattern information generation process, or whether this is the first execution of the driving pattern information generation process. If the pressure loss information has changed or this is the first execution (step S21 YES), the driving pattern information generation unit 32b proceeds to step S22, and if the pressure loss information has not changed (step S21 NO), the driving pattern information generation process ends.

In step S22, the driving pattern information generation unit 32b initializes the counter variable D to D = 0.

Next, in step S23, the driving pattern information generation unit 32b initializes the counter variable d to d = 0 and adds 1 to the counter variable D.

Next, in step S24, the operation pattern information generation unit 32b executes the "select compressors to operate at full load from among all constant speed machines" process. Details of the "select compressors to operate at full load from among all constant speed machines" process will be described later with reference to Figure 19.

Next, in step S25, the operation pattern information generation unit 32b executes the process of "selecting a compressor to operate at full load from among variable speed machines without pressure loss." Details of the process of "selecting a compressor to operate at full load from among variable speed machines without pressure loss" will be described later with reference to Figure 20.

Next, in step S26, the operation pattern information generation unit 32b executes the process of "selecting a compressor to perform capacity control operation from among variable speed compressors without pressure loss." Details of the process of "selecting a compressor to perform capacity control operation from among variable speed compressors without pressure loss" will be described later with reference to Figure 21.

Next, in step S27, the operation pattern information generation unit 32b executes the process of "selecting a compressor to perform capacity control operation from among constant speed compressors without pressure loss." Details of the process of "selecting a compressor to perform capacity control operation from among constant speed compressors without pressure loss" will be described later with reference to Figure 22.

Next, in step S28, the operation pattern information generation unit 32b executes the process of "selecting a compressor to perform capacity control operation from among variable speed machines with pressure loss." Details of the process of "selecting a compressor to perform capacity control operation from among variable speed machines with pressure loss" will be described later with reference to Figure 23.

Next, in step S29, the operation pattern information generation unit 32b executes the process of "selecting a compressor to perform capacity control operation from among constant speed compressors with pressure loss." Details of the process of "selecting a compressor to perform capacity control operation from among constant speed compressors with pressure loss" will be described later with reference to Figure 24.

Next, in step S30, the driving pattern information generation unit 32b determines whether the counter variable D = M + N (M is the total number of fixed-speed machines, and N is the total number of variable-speed machines). If the counter variable D = M + N (step S30 YES), the driving pattern information generation unit 32b proceeds to step S31, and if the counter variable D ≠ M + N (step S30 NO), the driving pattern information generation unit 32b returns to step S31.

In step S31, the operation pattern information generation unit 32b copies the operation pattern information for d = 1 to (M + N) generated by repeating steps S23 to S30 in reverse order of d. Specifically, using the example in Figure 8, operation pattern information for air usage ratios of 0 to 100 (d = 1), 100 to 200 (d = 2), 200 to 300 (d = 3), ..., (M + N - 1) x 100 to (M + N) x 100 (d = M + N) (%) is copied to the right of the axis of symmetry in reverse order of d, with air usage ratio = (M + N) x 100 (%) as the axis of symmetry.

Next, in step S32, the operation pattern information generation unit 32b averages the operation periods of each compressor 4 based on the information in the operation period allocation table 31c. To explain this in detail using the example of Figure 8, simply copying the operation pattern information to the right of the symmetry axis, with the air usage ratio = (M + N) x 100 (%) as the axis of symmetry, in reverse order of d, will result in differences between the operation periods of the constant speed units Fi and variable speed units Vj in the operation pattern table 31d and the operation periods shown in the operation period allocation table 31c. The operation pattern information generation unit 32b swaps the operation periods of the constant speed units Fi and variable speed units Vj to make the operation periods identical between the operation pattern table 31d and the operation period allocation table 31c.

Next, in step S33, if the changed operating pattern information newly created in the processing of step S32 is more energy-efficient than the operating pattern information before the change, the operating pattern information generation unit 32b updates the pressure loss information table 31a with the changed operating pattern information. On the other hand, if the changed operating pattern information is more energy-efficient than the operating pattern information before the change, the operating pattern information generation unit 32b discards the changed operating pattern and maintains the operating pattern information before the change.

Figure 19 is a detailed flow of step S24 of the driving pattern information generation process of Figure 18. First, in step S24a, the driving pattern information generation unit 32b sets the counter variable i = 1. Next, in step S24b, the driving pattern information generation unit 32b determines whether the counter variable D ≠ 1 and d < D-1. If the counter variable D ≠ 1 and d < D-1 (step S24b YES), the driving pattern information generation unit 32b proceeds to step S24c. If the counter variable D = 1 or d ≥ D (step S24b NO), the driving pattern information generation unit 32b proceeds to step S25 (Figure 18).

In step S24c, the operation pattern information generation unit 32b references the pressure loss information table 31a and determines whether the constant speed machine Fi has no pressure loss. If the constant speed machine Fi has no pressure loss (step S24c YES), the operation pattern information generation unit 32b proceeds to step S24d. If the constant speed machine Fi has a pressure loss (step S24c NO), the operation pattern information generation unit 32b proceeds to step S24f.

In step S24d, the operation pattern information generation unit 32b sets full load operation for the constant speed machine Fi in the operation pattern table 31d.

On the other hand, in step S24f, the driving pattern information generation unit 32b adds 1 to the counter variable i. Next, in step S24g, the driving pattern information generation unit 32b determines whether i > M (M is the total number of constant speed machines Fi). If i > M (step S24g YES), the driving pattern information generation unit 32b proceeds to step S24h, and if i ≦ M (step S24g NO), the driving pattern information generation unit 32b proceeds to step S24b.

In step S24h, the driving pattern information generation unit 32b determines whether d < D - N. If d < D - N (step S24h YES), the driving pattern information generation unit 32b proceeds to step S24i. If d ≥ D - N (step S24h NO), the driving pattern information generation unit 32b proceeds to step S25 (Figure 18).

In step S24i, the driving pattern information generation unit 32b sets the counter variable i = 1. Next, in step S24j, the driving pattern information generation unit 32b determines whether the counter variable D ≠ 1 and d < D-1. If the counter variable D ≠ 1 and d < D-1 (step S24j YES), the driving pattern information generation unit 32b proceeds to step S24k. If the counter variable D = 1 or d ≥ D (step S24j NO), the driving pattern information generation unit 32b proceeds to step S25 (Figure 18).

In step S24k, the operation pattern information generation unit 32b references the pressure loss information table 31a and determines whether the constant speed machine Fi has a pressure loss. If the constant speed machine Fi has a pressure loss (step S24k YES), the operation pattern information generation unit 32b proceeds to step S24l. If the constant speed machine Fi does not have a pressure loss (step S24k NO), the operation pattern information generation unit 32b proceeds to step S24n.

In step S24l, the operation pattern information generation unit 32b sets full load operation for the constant speed machine Fi in the operation pattern table 31d.

On the other hand, in step S24n, the driving pattern information generation unit 32b adds 1 to the counter variable i. Next, in step S24o, the driving pattern information generation unit 32b determines whether i > M (M is the total number of constant speed machines Fi). If i > M (step S24o YES), the driving pattern information generation unit 32b proceeds to step S25 (Figure 18), and if i ≤ M (step S24o NO), the driving pattern information generation unit 32b proceeds to step S24j.

Figure 20 is a detailed flow of step S25 of the driving pattern information generation process of Figure 18. First, in step S25a, the driving pattern information generation unit 32b sets counter variable j = 1. Next, in step S25b, the driving pattern information generation unit 32b determines whether counter variable D ≠ 1 and d < D-1. If counter variable D ≠ 1 and d < D-1 (step S25b YES), the driving pattern information generation unit 32b proceeds to step S25c. If counter variable D = 1 or d ≥ D (step S25b NO), the driving pattern information generation unit 32b proceeds to step S26 (Figure 18).

In step S25c, the operation pattern information generation unit 32b refers to the pressure loss information table 31a and determines whether the variable speed unit Vj has no pressure loss. If the variable speed unit Vj has no pressure loss (step S25c YES), the operation pattern information generation unit 32b proceeds to step S25d. If the variable speed unit Vj has a pressure loss (step S25c NO), the operation pattern information generation unit 32b proceeds to step S25f.

In step S25d, the driving pattern information generation unit 32b sets full load operation for the variable speed machine Vj in the driving pattern table 31d.

On the other hand, in step S25f, the driving pattern information generation unit 32b adds 1 to the counter variable j. Next, in step S25g, the driving pattern information generation unit 32b determines whether j > N (N is the total number of variable speed units Vj). If j > N (step S25g YES), the driving pattern information generation unit 32b proceeds to step S26 (Figure 18), and if j ≤ N (step S25g NO), the driving pattern information generation unit 32b proceeds to step S25b.

Figure 21 is a detailed flow of step S26 of the driving pattern information generation process of Figure 18. First, in step S26a, the driving pattern information generation unit 32b sets counter variable j = 1. Next, in step S26b, the driving pattern information generation unit 32b determines whether counter variable d = D. If counter variable d = D (step S26b YES), the driving pattern information generation unit 32b proceeds to step S26c, and if counter variable d ≠ D (step S26b NO), the driving pattern information generation unit 32b proceeds to step S26f.

In step S26c, the operation pattern information generation unit 32b determines whether the variable speed machine Vj has no pressure loss and has already been set to operate when d<D-1 (step S25d in Figure 20 has been executed). If the variable speed machine Vj has no pressure loss and has not already been set to operate (step S26c YES), the operation pattern information generation unit 32b proceeds to step S26d. If the variable speed machine Vj has a pressure loss or has already been set to operate (step S26c NO), the operation pattern information generation unit 32b proceeds to step S26f.

In step S26d, the driving pattern information generation unit 32b sets the variable speed drive Vj to capacity control operation. Next, in step S26e, the driving pattern information generation unit 32b adds 1 to the counter variable d.

On the other hand, in step S26f, the driving pattern information generation unit 32b adds 1 to the counter variable j. Next, in step S26g, the driving pattern information generation unit 32b determines whether j > N (N is the total number of variable speed units Vj). If j > N (step S26g YES), the driving pattern information generation unit 32b proceeds to step S27 (Figure 18), and if j ≤ N (step S26g NO), the driving pattern information generation unit 32b proceeds to step S26b.

Figure 22 is a detailed flow of step S27 of the driving pattern information generation process of Figure 18. First, in step S27a, the driving pattern information generation unit 32b sets the counter variable i = 1. Next, in step S27b, the driving pattern information generation unit 32b determines whether the counter variable d = D-1. If the counter variable d = D-1 (step S27b YES), the driving pattern information generation unit 32b proceeds to step S27c, and if the counter variable d ≠ D-1 (step S27b NO), the driving pattern information generation unit 32b proceeds to step S28 (Figure 10).

In step S27c, the operation pattern information generation unit 32b determines whether the constant speed machine Fi has no pressure loss and has already been set to operate (steps S24d and S24l in FIG. 19 have been executed). If the constant speed machine Fi has no pressure loss and has not already been set to operate (step S27c YES), the operation pattern information generation unit 32b proceeds to step S27d. If the variable speed machine Vj has a pressure loss or has already been set to operate (step S27c NO), the operation pattern information generation unit 32b proceeds to step S27f.

In step S27d, the driving pattern information generation unit 32b sets the constant speed machine Fi to capacity control operation. Next, in step S27e, the driving pattern information generation unit 32b adds 1 to the counter variable d.

On the other hand, in step S27f, the driving pattern information generation unit 32b adds 1 to the counter variable i. Next, in step S27g, the driving pattern information generation unit 32b determines whether i > M (M is the total number of constant speed machines Fi). If i > M (step S27g YES), the driving pattern information generation unit 32b proceeds to step S28 (Figure 18), and if i ≤ M (step S27g NO), the driving pattern information generation unit 32b proceeds to step S27b.

Figure 23 is a detailed flow of step S28 of the driving pattern information generation process of Figure 18. First, in step S28a, the driving pattern information generation unit 32b sets counter variable j = 1. Next, in step S28b, the driving pattern information generation unit 32b determines whether counter variable d = D-1. If counter variable d = D-1 (step S28b YES), the driving pattern information generation unit 32b proceeds to step S28c, and if counter variable d ≠ D-1 (step S28b NO), the driving pattern information generation unit 32b proceeds to step S29 (Figure 18).

In step S28c, the operation pattern information generation unit 32b determines whether the variable speed unit Vj has a pressure loss. If the variable speed unit Vj has a pressure loss (step S28c YES), the operation pattern information generation unit 32b proceeds to step S28d. If the variable speed unit Vj does not have a pressure loss (step S28c NO), the operation pattern information generation unit 32b proceeds to step S28f.

In step S28d, the driving pattern information generation unit 32b sets the variable speed drive Vj to capacity control operation. Next, in step S28e, the driving pattern information generation unit 32b adds 1 to the counter variable d.

On the other hand, in step S28f, the driving pattern information generation unit 32b adds 1 to the counter variable j. Next, in step S28g, the driving pattern information generation unit 32b determines whether j > N (N is the total number of variable speed units Vj). If j > N (step S28g YES), the driving pattern information generation unit 32b proceeds to step S29 (Figure 10), and if j ≤ N (step S28g NO), the driving pattern information generation unit 32b proceeds to step S28b.

Figure 24 is a detailed flow of step S29 of the driving pattern information generation process of Figure 18. First, in step S29a, the driving pattern information generation unit 32b sets the counter variable i = 1. Next, in step S29b, the driving pattern information generation unit 32b determines whether the counter variable d = D-1. If the counter variable d = D-1 (step S28b YES), the driving pattern information generation unit 32b proceeds to step S29c, and if the counter variable d ≠ D-1 (step S29b NO), the driving pattern information generation unit 32b proceeds to step S30 (Figure 18).

In step S29c, the operation pattern information generation unit 32b determines whether the constant speed machine Fi has a pressure loss and operation has already been set (steps S24d and S24l in FIG. 19, and step S27d in FIG. 22 have been executed). If the constant speed machine Fi has a pressure loss and operation has not already been set (step S29c YES), the operation pattern information generation unit 32b proceeds to step S29d. If the constant speed machine Fi has no pressure loss or operation has already been set (step S29c NO), the operation pattern information generation unit 32b proceeds to step S29f.

In step S29d, the driving pattern information generation unit 32b sets the constant speed unit Fi to capacity control operation. Next, in step S29e, the driving pattern information generation unit 32b adds 1 to the counter variable d.

On the other hand, in step S29f, the driving pattern information generation unit 32b adds 1 to the counter variable i. Next, in step S29g, the driving pattern information generation unit 32b determines whether i > M (M is the total number of constant speed machines Fi). If i > M (step S29g YES), the driving pattern information generation unit 32b proceeds to step S30 (Figure 10), and if i ≤ M (step S29g NO), the driving pattern information generation unit 32b proceeds to step S29b.

In this embodiment, the execution order of steps S24 to S29 in Figure 18 is changed as appropriate by comparing the power efficiency of each pattern: full load operation of a constant speed machine without pressure loss, capacity control operation of a constant speed machine without pressure loss, full load operation of a constant speed machine with pressure loss, capacity control operation of a constant speed machine with pressure loss, full load operation of a variable speed machine without pressure loss, capacity control operation of a variable speed machine without pressure loss, full load operation of a variable speed machine with pressure loss, and capacity control operation of a variable speed machine with pressure loss. The order can be changed as appropriate to prioritize operation of the compressor 4 with better power efficiency and restrict operation of the compressor 4 with lower power efficiency.

<Effects of the embodiment>
In the above-described embodiment, among the multiple compressors 4, operation of a compressor with a higher power efficiency according to the detected physical quantity is given priority, and operation of a compressor with a lower power efficiency is restricted. Therefore, in the compressor system 1 in which the multiple compressors 4 are operated in turn according to the load, a decrease in the power efficiency of the entire compressor system 1 can be suppressed by shortening the operating period of a compressor 4 in which a pressure loss is occurring or by operating the compressor at a low rotation speed.

Furthermore, in the above-described embodiment, by controlling the operation of multiple compressors 4 so as to optimize the power efficiency of the entire compressor system 1, it is possible to minimize the decrease in the power efficiency of the entire compressor system 1 even in situations where pressure loss is occurring in some compressors 4.

Furthermore, in the above-described embodiment, the multiple compressors 4 include variable speed machines Vj that can variably control the speed of the compressor main body 45, and constant speed machines Fi that control the compressor main body 45 at a constant speed. Therefore, even in a compressor system 1 that combines variable speed machines Vj and constant speed machines Fi, it is possible to suppress a decrease in the power efficiency of the entire compressor system 1 due to pressure loss.

In the above-described embodiment, the filters include at least one of various filters provided at each of multiple locations. The various filters include an outside air filter 46 that filters air passing through the outside air inlet, an intake air filter 47 that filters air taken in from the intake section of the compressor main body 45, and a separator element that filters compressed air discharged from each compressor 4. The intake pressure loss due to the filter is the pressure loss due to the outside air filter 46, the pressure loss due to the intake air filter 47, or the pressure loss due to the separator element. Therefore, a decrease in the power efficiency of the entire compressor system 1 can be suppressed due to pressure loss caused by clogging of any filter.

Furthermore, in the above-described embodiment, the power efficiency corresponding to the detected physical quantity is the rated power efficiency of each compressor 4 minus the efficiency reduction caused by suction pressure loss due to the filter. Therefore, priority is given to operating the compressor 4 with the best power efficiency after taking pressure loss into consideration, thereby suppressing the reduction in power efficiency of the entire compressor system 1 due to pressure loss.

In addition, in the above-described embodiment, the pressure loss due to the outside air filter 46 is determined based on the pressure of the air after passing through the outside air filter 46 and the outside air inlet 42, the pressure loss due to the intake filter 47 is determined based on the temperature of the air taken in from the intake section of the compressor main body 45, and the pressure loss due to the separator element is determined based on the discharge pressure of the air compressed by each compressor 4 and the pressure in the air tank 5 where the air joins. Therefore, the reduction in the power efficiency of the entire compressor system 1 can be appropriately suppressed with respect to the pressure loss of each filter, which is appropriately determined using the detection values of the sensors corresponding to each filter.

Furthermore, in the above-described embodiment, the greater the efficiency reduction caused by the suction pressure loss due to the filter, the greater the restriction on operation of the compressor with a lower power efficiency according to the detected physical quantity. Therefore, compressors 4 with a greater efficiency reduction are excluded from operation as much as possible, thereby further suppressing the reduction in power efficiency of the entire compressor system 1 due to pressure loss.

Furthermore, in the above-described embodiment, the operation restriction on the compressor 4 includes stopping the operation of the compressor 4 and reducing the operation. Therefore, a compressor 4 with a large efficiency drop is stopped if possible and is operated only when operation is unavoidable, thereby achieving a desired air usage ratio and suppressing a drop in the power efficiency of the entire compressor system 1 due to pressure loss at the same time.

Furthermore, in the above-described embodiment, by notifying the user of the compressor system 1 to perform filter maintenance on the compressor 4 while it is not in operation, the user can be assured of performing filter maintenance efficiently and at the optimal time.

Furthermore, in the above-described embodiment, among the multiple compressors 4, the compressor 4 with the higher power efficiency according to the detected pressure is operated preferentially, and if restricting the operation of the compressors 4 with the lower power efficiency would reduce the power efficiency of the entire compressor system 1, the operation of the higher compressor 4 and the operation of the lower compressor 4 are not restricted. Therefore, the inconvenience of reducing the power efficiency of the entire compressor system 1 by operating and restricting the operation of the compressor 4 can be prevented.

The present invention is not limited to the above-described embodiments and includes various modifications. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and are not necessarily limited to those including all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another example, or to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is possible to add, delete, replace, integrate, or distribute part of the configuration of each embodiment with other configurations. Furthermore, each process shown in the embodiments may be distributed or integrated as appropriate based on processing efficiency or implementation efficiency.

1: Compressor system, 2: Management device, 3: Compressor control device, 4: Compressor, Fi: Fixed speed compressor, Fj: Variable speed compressor

Claims (13)

A compressor system having a plurality of compressors and a compressor control device that controls operation of the plurality of compressors,
Each of the compressors comprises:
A filter for filtering the air,
a compressor body that compresses air;
a detection means for detecting a physical quantity correlated with the pressure loss of the compressor body,
The plurality of compressors include a constant speed compressor that controls the compressor main body at a constant speed to keep the amount of compressed air produced constant, and a variable speed compressor that controls the compressor main body at a variable speed to increase or decrease the amount of compressed air produced,
The constant speed machine performs a full load operation in which the amount of compressed air produced is kept constant by constantly repeating periods of loading and unloading at a constant rotation speed of a motor provided in the constant speed machine, and a capacity control operation in which the amount of compressed air produced is increased or decreased by adjusting and repeating periods of loading and unloading at a constant rotation speed of the motor,
the variable speed machine performs a full load operation in which the rotation speed of a motor provided in the variable speed machine is set at full load to keep the amount of compressed air produced constant, and a capacity control operation in which the rotation speed of the motor is adjusted to increase or decrease the amount of compressed air produced,
The physical quantity is any one of a suction pressure of the filter, a temperature around an intake part of the compressor, and an intake temperature of the compressor,
The compressor control device includes:
When determining which of the plurality of compressors is to be subjected to the full load operation and which is to be subjected to the capacity control operation, in order to preferentially operate a compressor having a higher power efficiency according to any one of the suction pressure of the filter detected by the detection means, the temperature around the intake part of the compressor, and the intake temperature of the compressor, and to restrict operation of a compressor having a lower power efficiency,
selecting, from among all of the plurality of compressors, a compressor to be operated at full load in the order of priority, the constant speed compressor having a power efficiency equal to or greater than a certain level according to the physical quantity detected by the detection means, the variable speed compressor having a power efficiency equal to or greater than the certain level, and the constant speed compressor having a power efficiency less than the certain level;
After the compressor to be operated at full load is selected, a compressor to be operated at full load is selected from among the plurality of compressors not selected as compressors to be operated at full load in the order of priority: the variable speed compressor having a power efficiency equal to or greater than a certain level, the constant speed compressor having a power efficiency equal to or greater than a certain level, the variable speed compressor having a power efficiency less than a certain level, and the constant speed compressor having a power efficiency less than a certain level.
A compressor system comprising: 2. The compressor system of claim 1,
The compressor control device includes:
A compressor system, characterized in that operation of the plurality of compressors is controlled so as to optimize power efficiency of the entire compressor system. 2. The compressor system of claim 1,
In each of the compressors,
The compressor system, wherein the filter includes at least one of various filters provided at a plurality of locations. 4. The compressor system of claim 3 ,
the filters include an outside air filter that filters air passing through an outside air inlet, an intake air filter that filters air taken in from an intake section of the compressor main body, and a separator element that filters compressed air discharged from each compressor. 5. The compressor system of claim 4 ,
the power efficiency according to the physical quantity detected by the detection means is a power efficiency obtained by subtracting a reduction in efficiency caused by a suction pressure loss due to the filter from the rated power efficiency of each compressor. 6. The compressor system of claim 5 ,
a suction pressure loss due to the filter being a pressure loss due to the outside air filter, a pressure loss due to the intake air filter, or a pressure loss due to the separator element; 7. The compressor system of claim 6 ,
The pressure loss due to the outside air filter is determined based on the pressure of air after passing through the outside air filter and the outside air inlet,
The pressure loss caused by the intake filter is determined based on the temperature of air taken in from an intake portion of the compressor body,
a compressor system, characterized in that the pressure loss caused by the separator element is determined based on the discharge pressure of the air compressed by each compressor and the pressure in an air tank where the air joins. 6. The compressor system of claim 5 ,
the greater the efficiency reduction caused by the suction pressure loss due to the filter, the greater the restriction on operation of a compressor having a lower power efficiency according to the physical quantity detected by the detection means. 2. The compressor system of claim 1,
The compressor system, wherein the restriction on the operation of the compressor includes stopping the operation of the compressor and reducing the operation of the compressor. 2. The compressor system of claim 1,
A compressor system comprising: a compressor system configured to notify a user of the compressor system to prompt the user to perform maintenance on the filter of the compressor that is currently out of operation. 2. The compressor system of claim 1,
The compressor control device includes:
a compressor system, characterized in that, among the plurality of compressors, a compressor having a higher power efficiency according to the pressure detected by the detection means is operated preferentially, and if restricting the operation of a compressor having a lower power efficiency would result in a decrease in the power efficiency of the entire compressor system, the operation of the compressor having the higher power efficiency and the operation of the compressor having the lower power efficiency are not restricted. A compressor control device that controls operation of a plurality of compressors in a compressor system,
Each of the compressors comprises:
A filter for filtering the air,
a compressor body that compresses air;
a detection means for detecting a physical quantity correlated with the pressure loss of the compressor body,
The plurality of compressors include a constant speed compressor that controls the compressor main body at a constant speed to keep the amount of compressed air produced constant, and a variable speed compressor that controls the compressor main body at a variable speed to increase or decrease the amount of compressed air produced,
The constant speed machine performs a full load operation in which the amount of compressed air produced is kept constant by constantly repeating periods of loading and unloading at a constant rotation speed of a motor provided in the constant speed machine, and a capacity control operation in which the amount of compressed air produced is increased or decreased by adjusting and repeating periods of loading and unloading at a constant rotation speed of the motor,
the variable speed machine performs a full load operation in which the rotation speed of a motor provided in the variable speed machine is set at full load to keep the amount of compressed air produced constant, and a capacity control operation in which the rotation speed of the motor is adjusted to increase or decrease the amount of compressed air produced,
The physical quantity is any one of a suction pressure of the filter, a temperature around an intake part of the compressor, and an intake temperature of the compressor,
When determining which of the plurality of compressors is to perform the full load operation and which is to perform the capacity control operation, in order to preferentially operate a compressor having a higher power efficiency according to any one of the suction pressure of the filter detected by the detection means, the temperature around the intake part of the compressor, and the intake temperature of the compressor, and to restrict operation of a compressor having a lower power efficiency,
selecting, from among all of the plurality of compressors, a compressor to be operated at full load in the order of priority, the constant speed compressor having a power efficiency equal to or greater than a certain level according to the physical quantity detected by the detection means, the variable speed compressor having a power efficiency equal to or greater than the certain level, and the constant speed compressor having a power efficiency less than the certain level;
After the compressor to be operated at full load is selected, a compressor to be operated at full load is selected from among the plurality of compressors not selected as compressors to be operated at full load in the order of priority: the variable speed compressor having a power efficiency equal to or greater than a certain level, the constant speed compressor having a power efficiency equal to or greater than a certain level, the variable speed compressor having a power efficiency less than a certain level, and the constant speed compressor having a power efficiency less than a certain level.
A compressor control device characterized by: A compressor control method performed by a compressor control device in a compressor system having a plurality of compressors and a compressor control device that controls operation of the plurality of compressors, comprising:
Each of the compressors comprises:
A filter for filtering the air,
a compressor body that compresses the air;
a detection means for detecting a physical quantity correlated with the pressure loss of the compressor body,
The plurality of compressors include a constant speed compressor that controls the compressor main body at a constant speed to keep the amount of compressed air produced constant, and a variable speed compressor that controls the compressor main body at a variable speed to increase or decrease the amount of compressed air produced,
The constant speed machine performs a full load operation in which the amount of compressed air produced is kept constant by constantly repeating periods of loading and unloading at a constant rotation speed of a motor provided in the constant speed machine, and a capacity control operation in which the amount of compressed air produced is increased or decreased by adjusting and repeating periods of loading and unloading at a constant rotation speed of the motor,
the variable speed machine performs a full load operation in which the rotation speed of a motor provided in the variable speed machine is set at full load to keep the amount of compressed air produced constant, and a capacity control operation in which the rotation speed of the motor is adjusted to increase or decrease the amount of compressed air produced,
The physical quantity is any one of a suction pressure of the filter, a temperature around an intake part of the compressor, and an intake temperature of the compressor,
The compressor control device,
When determining which of the plurality of compressors is to be subjected to the full load operation and which is to be subjected to the capacity control operation, in order to preferentially operate a compressor having a higher power efficiency according to any one of the suction pressure of the filter detected by the detection means, the temperature around the intake part of the compressor, and the intake temperature of the compressor, and to restrict operation of a compressor having a lower power efficiency,
selecting, from among all of the plurality of compressors, a compressor to be operated at full load in the order of priority, the constant speed compressor having a power efficiency equal to or greater than a certain level according to the physical quantity detected by the detection means, the variable speed compressor having a power efficiency equal to or greater than the certain level, and the constant speed compressor having a power efficiency less than the certain level;
After the compressor to be operated at full load is selected, a compressor to be operated at full load is selected from among the plurality of compressors not selected as compressors to be operated at full load in the order of priority: the variable speed compressor having a power efficiency equal to or greater than a certain level, the constant speed compressor having a power efficiency equal to or greater than a certain level, the variable speed compressor having a power efficiency less than a certain level, and the constant speed compressor having a power efficiency less than a certain level.
A compressor control method comprising: