JP7626583B2 - Method for obtaining differential pressure in an air conditioning system and device for obtaining differential pressure in an air conditioning system - Google Patents

Description

The present invention relates to a method for obtaining a pressure difference in an air conditioning system and a device for obtaining a pressure difference in an air conditioning system.

Air conditioning equipment supplies temperature-regulated air indoors. Air conditioning equipment is equipped with an air handling unit, which is a type of heat exchanger. The air handling unit receives heat transfer media such as cold water or hot water from the heat source equipment, and exchanges heat between the heat transfer media and air to supply regulated air.

Katsuhiro Miura, Kuniaki Mihara, Tatsuo Nagai, Masatora Kojima, Research and Development of Fault Detection Technology for Energy Consumption in Building Facilities (Part 8) Proposal of Reproduction and Improvement Method of Operation State of Secondary Water Conveyor System, Proceedings of the Annual Conference of the Society of Heating, Air-Conditioning and Sanitary Engineers of Japan, Japan, Society of Heating, Air-Conditioning and Sanitary Engineers of Japan, 2008, H54, pp. 1223-1226.

An air conditioning system has multiple system parameters. When the system is operated, a controlled parameter selected from the multiple parameters is controlled so that it satisfies a predetermined condition. Therefore, before the air conditioning system is operated, the conditions that the controlled parameters must satisfy are set. For example, Non-Patent Document 1 discloses a method for appropriately setting the controlled parameters.

Here, differential pressure control is widely used as a flow control method in air conditioning equipment. For this reason, differential pressure is used as the controlled parameter. The target value for this control, that is, the differential pressure set value which is the target value for differential pressure control, is set by actually measuring the differential pressure of the air conditioning equipment. In other words, the differential pressure of the air conditioning equipment is actually measured using the target air conditioning equipment itself. Therefore, the controlled parameter is set at the end of the construction of the air conditioning equipment. As a result, it has been difficult to flexibly set the timing for obtaining the differential pressure of the air conditioning equipment without being affected by the progress of the building construction.

Therefore, the present invention provides a method for obtaining a differential pressure in an air conditioning system and a device for obtaining a differential pressure in an air conditioning system that allows for flexible setting of the timing for obtaining the differential pressure in the air conditioning system regardless of the progress of building construction.

One aspect of the present invention is a method for obtaining a differential pressure in an air conditioning system, comprising a liquid supply unit that supplies liquid to a measurement target unit constituted by components of the air conditioning system, a liquid recovery unit that recovers liquid discharged from the measurement target unit, and a differential pressure acquisition unit that obtains the differential pressure in the measurement target unit, the method comprising a first step of connecting the liquid supply unit to the upstream side of the measurement target unit and connecting the liquid recovery unit to the downstream side of the measurement target unit, a second step of using the differential pressure acquisition unit to obtain the differential pressure in a state in which a predetermined flow rate of liquid is supplied to the measurement target unit, and a third step of removing the liquid supply unit and the liquid recovery unit from the measurement target unit.

Another aspect of the present invention is a device for obtaining a differential pressure in an air conditioning system, comprising a liquid supply unit that supplies a predetermined flow rate of liquid to a measurement target unit constituted by components of the air conditioning system, a liquid recovery unit that recovers liquid discharged from the measurement target unit, and a differential pressure acquisition unit that obtains the differential pressure in the measurement target unit when liquid is flowing at the predetermined flow rate.

In this method and device, the differential pressure measuring device is attached to the measurement target portion via the liquid supply portion and the liquid recovery portion. In other words, to obtain the differential pressure, it is sufficient that the measurement target portion is prepared, and the construction state of the air conditioning equipment including the measurement target portion does not matter. As a result, this method and device can be applied at the end of the construction of the air conditioning equipment including the measurement target portion, and can also be applied, for example, even when only the measurement target portion is arranged in the building. In fact, it does not even matter whether the measurement target portion is arranged in the building. Therefore, this method and device allows the timing of obtaining the differential pressure of the air conditioning equipment to be flexibly set.

In the above method, the second step may include a step of changing the value of the predetermined flow rate, and a step of obtaining the differential pressure after the change. According to this method, it is possible to obtain multiple relationships between the flow rate and the differential pressure. In other words, it is possible to obtain the relationship between the flow rate and the differential pressure when the air conditioning equipment is operated at high speed, and the relationship between the flow rate and the differential pressure when the air conditioning equipment is operated at low speed. Therefore, it is possible to obtain the numerical values of multiple control parameters that can be used to control the air conditioning equipment.

The method and device for obtaining a differential pressure in an air conditioning system of the present invention make it possible to flexibly set the timing for obtaining a differential pressure in an air conditioning system, regardless of the progress of building construction.

FIG. 1 is a diagram showing the configuration of an air conditioning system to which a method and device for obtaining a differential pressure in an air conditioning system according to an embodiment is applied. FIG. 2 is a flow diagram of a method for obtaining a differential pressure in an air conditioning installation according to an embodiment. FIG. 3 is a diagram showing a state in which the differential pressure measuring device is attached to an air conditioning system. FIG. 4 is a block diagram showing the configuration of the control unit. FIG. 5 is a flow diagram of a method for obtaining a differential pressure in an air conditioning system, which is a partial modification of the flow of the embodiment. FIG. 6 is a graph for explaining a method for obtaining a differential pressure in the air conditioning system shown in FIG. FIG. 7 is a connection diagram for explaining a method of obtaining a pressure difference in an air conditioning system according to the first modified example. FIG. 8 is a connection diagram for explaining a method of obtaining a pressure difference in an air conditioning system according to the second modification. Part (a) of FIG. 9 shows a measurement target part of the embodiment, part (b) of FIG. 9 is a modified example of the measurement target part, and part (c) of FIG. 9 is yet another modified example of the measurement target part. FIG. 10 is another example of an air conditioning system to which the method and device for obtaining a differential pressure in an air conditioning system according to the embodiment is applied.

Below, the embodiment of the present invention will be described in detail with reference to the attached drawings. In the description of the drawings, the same elements are given the same reference numerals, and duplicate explanations will be omitted.

Figure 1 shows an example of an air conditioning system 100 to which the method and device of the embodiment are applied. The air conditioning system 100 uses a heat medium supplied from a heat source system 200 to supply conditioned air indoors. An example of the heat medium is liquid water, such as cold water, hot water, or heat source water. The air conditioning system 100 has, as its main components, a pump unit 101, a flow rate measurement unit 102, an air conditioning section 103, a differential pressure gauge 104, and valves 105, 106, and 107.

The pump unit 101 supplies water supplied from the heat source equipment 200 to the air conditioning unit 103. The pump unit 101 is connected downstream of the heat source equipment 200 and upstream of the air conditioning unit 103. The pump unit 101 includes at least one pump. The number of pumps in the pump unit 101 may be appropriately selected according to the required capacity. Furthermore, when the pump unit 101 includes multiple pumps, the number of pumps to be operated may be appropriately set according to the required flow rate.

The upstream side of the pump unit 101 is connected to the heat source equipment 200. On the other hand, the downstream side (connection 101a) of the pump unit 101 is connected to the main supply pipe 120. The main supply pipe 120 is provided with a plurality of supply branches 121, 122, 123, 124, and 125, and a valve 106 is provided at the end of the main supply pipe 120. Supply branches 131, 132, 133, 134, and 135 are connected to the supply branches 121, 122, 123, 124, and 125, respectively. The supply branches 131, 132, and 133 are connected to the upstream side of the air conditioning unit 103. The supply branch pipe 134 is connected to the upstream side of the differential pressure gauge 104. The supply branch pipe 135 is connected to the upstream side of the valve 105.

The flow rate measurement unit 102 measures the flow rate of water. The flow rate measurement unit 102 is connected downstream of the air conditioning unit 103 and upstream of the heat source equipment 200. According to this connection configuration, the water supplied from the heat source equipment 200 passes through the pump unit 101, the air conditioning unit 103, and the flow rate measurement unit 102 in that order, and then returns to the heat source equipment 200. Note that the air conditioning equipment 100 shown in FIG. 1 also includes a path that directly connects the flow rate measurement unit 102 and the pump unit 101 without passing through the air conditioning unit 103.

The downstream side of the flow rate measurement unit 102 is connected to the heat source equipment 200. On the other hand, the upstream side (connection part 102a) of the flow rate measurement unit 102 is connected to the recovery main pipe 140. The recovery main pipe 140 is provided with a plurality of recovery branch parts 141, 142, 143, 144, 145, and a valve 107 is provided at the end of the recovery main pipe 140. Recovery branch parts 141, 142, 143, 144, 145 are respectively connected to recovery branch pipes 151, 152, 153, 154, 155. These recovery branch pipes 151, 152, 153, 154, 155 correspond to the supply branch pipes 131, 132, 133, 134, 135, respectively. The recovery branch pipes 151, 152, 153 are connected to the downstream side of the air conditioning unit 103. The recovery branch pipe 154 is connected downstream of the differential pressure gauge 104. The recovery branch pipe 155 is connected downstream of the valve 105.

The air conditioning unit 103 exchanges heat between the water supplied from the pump unit 101 and the air, and supplies the conditioned air indoors. The air conditioning unit 103 is connected to the downstream side of the pump unit 101 and the upstream side of the flow measurement unit 102. A differential pressure gauge 104 and valves 105, 106, and 107 are also connected to the air conditioning unit 103. In the example shown in FIG. 1, the air conditioning unit 103 includes three heat exchange units 111, 112, and 113. These heat exchange units 111, 112, and 113 may be, for example, air handling units, fan coil units, or water-cooled heat pumps.

The heat exchange sections 111, 112, and 113 are connected in parallel to each other. The upstream sides of the heat exchange sections 111, 112, and 113 are connected to the valves 111a, 112a, and 113a. The upstream sides of the valves 111a, 112a, and 113a are connected to the supply branch pipes 131, 132, and 133. The downstream sides of the heat exchange sections 111, 112, and 113 are connected to the flow control valves 111b, 112b, and 113b. The downstream sides of the flow control valves 111b, 112b, and 113b are connected to the recovery branch pipes 151, 152, and 153.

The flow control valves 111b, 112b, and 113b switch between an open operation and a closed operation in response to a control signal supplied from the control device 300. The "open operation" here means that water is allowed to flow through the heat exchange units 111, 112, and 113 by allowing the flow of water. On the other hand, the "close operation" means that water is not allowed to flow through the heat exchange units 111, 112, and 113 by prohibiting the flow of water. The flow control valves 111b, 112b, and 113b may adjust the flow rate according to their opening degree. The flow control valves 111b, 112b, and 113b may also be disposed upstream of the heat exchange units 111, 112, and 113. Furthermore, the flow control valves 111b, 112b, and 113b may be manually switched between an open operation and a closed operation.

Terminal differential pressure control is one of the methods widely used as a flow control method in the above-mentioned air conditioning equipment 100. Terminal differential pressure control is a control that varies the flow rate so that the differential pressure at a predetermined position becomes the differential pressure set value, and the predetermined position is often between two points on the path where the piping resistance is maximum. By maintaining a differential pressure large enough to allow the design flow rate (predetermined flow rate) to flow through the heat exchange section located on the path where the piping resistance is maximum, a sufficient flow rate can always be supplied to the heat exchange section even when the opening of the flow control valve varies depending on the air conditioning load state.

In other words, the air conditioning equipment 100 includes different paths, and the relationship between flow rate and pressure loss may differ for each path. When selecting a path to be subjected to differential pressure control from among these paths, the path through which the designed flow rate is least likely to flow may be selected as the control target. The "path" here refers to the path from the pump unit 101 to the flow measurement unit 102.

For example, in the air conditioning equipment 100, the path with the greatest piping resistance is the path in which water discharged from the pump unit 101 passes through the supply main pipe 120, the supply branch pipe 133, the valve 113a, the heat exchanger 113, the flow control valve 113b, the recovery branch pipe 153, and the recovery main pipe 140 to the flow measurement unit 102. In this case, the heat exchanger arranged in the path with the greatest piping resistance corresponds to the heat exchanger 113. In this way, the heat exchanger included in the path adopted as the target of differential pressure control is called the terminal heat exchanger. The terminal heat exchanger adopted based on the flow rate and pressure loss is not limited to the one connected farthest from the pump unit 101 in terms of the pipe configuration. In terms of the pipe configuration, the heat exchanger through which the design flow rate is least likely to flow may be the one connected to the position farthest from the pump unit 101, or it may be the one connected to the position closest to the pump unit 101.

The criteria for selecting a terminal heat exchange section are not limited to the difficulty of flowing the design flow rate. In other words, the heat exchange section through which the design flow rate flows most difficult may not be selected as the terminal heat exchange section, but a heat exchange section through which the design flow rate flows more easily than the heat exchange section may be selected as the terminal heat exchange section. An example of this will be described later as Modification 2.

When the air conditioning equipment 100 is operated, a pressure difference large enough is maintained so that the designed flow rate flows through the heat exchanger 113, which is located in the path with the greatest piping resistance. A pressure difference gauge 104 is provided to monitor this pressure difference.

The value of this differential pressure to be maintained is one that allows the design flow rate to flow through the heat exchange section 113, and this value of differential pressure must be determined based on measurements, etc. The method and device of this embodiment obtain the differential pressure to be maintained in order to allow the design flow rate to flow through the heat exchange section 113.

In short, when the air conditioning equipment 100 shown in FIG. 1 is operated, the design flow rate and the differential pressure corresponding to the design flow rate are adopted as its control parameters. Therefore, before the air conditioning equipment 100 starts operation, it is necessary to obtain the relationship between the design flow rate and the differential pressure used for control. This relationship may be obtained, for example, at the end of construction of the building in which the air conditioning equipment 100 is installed, during the trial operation period after the construction of the air conditioning equipment 100 is completed. At the start of this trial operation, flushing of the inside of the piping, establishment of an automatic control system, and preparation of the main pump (pump unit 101 in FIG. 1) are required. In other words, the value of the differential pressure that must be maintained to flow the design flow rate to the heat exchanger 113 was obtained at the time when the construction staff was most busy, just before completion of the construction.

In this embodiment, the construction state of the air conditioning equipment 100 may be divided into a completed state and an incomplete state. The completed state here refers to a state in which water can be supplied from the pump unit 101 at the design flow rate. The incomplete state refers to a state in which water cannot be supplied from the pump unit 101 at the design flow rate. The method and device of this embodiment can be applied to both the completed state and the incomplete state.

The device and method according to this embodiment provide flexibility in the timing at which the differential pressure of the air conditioning equipment 100 can be obtained, making it possible to obtain the differential pressure of the air conditioning equipment 100 while avoiding the busy period immediately prior to completion of construction. Below, the method for obtaining the differential pressure of the air conditioning equipment 100 according to this embodiment and the device used in this method will be described with reference to Figures 2 and 3.

The method described below is based on the assumption that the path with the highest piping resistance has been selected in advance as the path that includes the heat exchange unit 113. The selection of the path with the highest piping resistance may be based on information obtained from design drawings, specifications, etc. Therefore, in the method described below, the differential pressure between two points on the path that includes the heat exchange unit 113 is obtained.

First, the differential pressure measuring device 1 (a device that obtains the differential pressure of the air conditioning equipment) is attached to the air conditioning equipment 100 (step S1: first step). The differential pressure measuring device 1 is additionally attached to and detached from the air conditioning equipment 100. In other words, the differential pressure measuring device 1 is not a permanent device, but is connected to the air conditioning equipment 100 when obtaining the differential pressure of the air conditioning equipment 100. The differential pressure measuring device 1 may be a permanent device.

[Differential pressure measuring device]
Here, the differential pressure measuring device 1 will be described. As shown in Fig. 3, the differential pressure measuring device 1 has a measuring section 20 and a connecting section 30. The measuring section 20 provides water at a design flow rate to a measured system for differential pressure measurement, and obtains the differential pressure when the design flow rate is provided. The connecting section 30 connects the measuring section 20 to a measured system including a heat exchange section 113 that is the target of terminal differential pressure control. Note that the measuring section 20 may be connected directly to the measured system including the heat exchange section 113 without going through the connecting section 30.

The measuring section 20 of the differential pressure measuring device 1 has a liquid recovery section 2, a flow meter 3, a pump 4, a liquid supply section 7, a control section 8, and a flow input section 8e. In addition to these, the measuring section 20 may be appropriately equipped with auxiliary parts such as a manual air vent valve 12a and a manual water drain valve 12b. The differential pressure measuring device 1 supplies water at a design flow rate to the air conditioning equipment 100 and obtains the differential pressure at that time. In other words, the method of this embodiment does not require the installation of the pump unit 101 and the flow measurement unit 102 that constitute the air conditioning equipment 100. Therefore, the method of this embodiment can be implemented even when the construction of the pump unit 101 and the flow measurement unit 102 that constitute the air conditioning equipment 100 has not been completed (the unfinished state described above).

In other words, the temporary differential pressure measuring device 1 may be configured to include a flowmeter 3, a pump 4, a high-pressure hose 15, an air vent valve 12a, and a differential pressure gauge 13. Since the pump 4 is intended to pass water through one heat exchanger 113, it is desirable to use, for example, a small pump. In this case, the power required to drive the pump is less than the power required for the permanent pump unit 101, so the transport energy required when measuring the differential pressure can be reduced. Furthermore, with this configuration, the pump 4 of the differential pressure measuring device 1 can measure the differential pressure when water is supplied to the terminal heat exchanger at the design flow rate. Then, the differential pressure may be adopted as the differential pressure setting value. In other words, the differential pressure measuring device 1 can automatically obtain the differential pressure setting value.

The liquid recovery section 2 receives water returning from the air conditioning equipment 100. The liquid recovery section 2 has a recovery end 2a, and is connected to the air conditioning equipment 100 via this recovery end 2a. Specifically, it is connected to the downstream side of the air conditioning unit 103. In the configuration illustrated in FIG. 3, the recovery end 2a of the liquid recovery section 2 is connected to a valve 107. The liquid recovery section 2 may be connected directly to the air conditioning equipment 100, or may be connected via a component such as a high-pressure hose 15. The liquid recovery section 2 is attached to the air conditioning equipment 100 in step S1, which will be described later. Then, it is removed from the air conditioning equipment 100 in step S3, which will be described later. Thus, the liquid recovery section 2 has a configuration that is detachable from the air conditioning equipment 100.

The upstream side of the flow meter 3 is connected to the liquid recovery section 2. The downstream side of the flow meter 3 is connected to the pump 4. The flow meter 3 measures the flow rate of water supplied from the liquid recovery section 2. This measurement value is supplied to the control section 8.

The flow meter that provides information to the flow rate acquisition unit 8a described later may be a flow meter installed at a desired position of the air conditioning equipment 100, or may be the flow meter 3 of the differential pressure measurement device 1. For example, when the flow rate acquisition unit 8a described later obtains information from a flow meter installed in the air conditioning equipment 100, the flow meter 3 in the differential pressure measurement device 1 may be omitted. On the other hand, when the flow meter 3 of the differential pressure measurement device 1 is used as in this embodiment, it is possible to use a highly accurate flow meter (e.g., an electromagnetic flow meter) that has been calibrated in advance. As a result, the measurement accuracy is improved, and a differential pressure that can obtain a desired design flow rate can be accurately obtained. In addition, when the flow meter 3 is installed in the differential pressure measurement device 1, an ideal installation state for the flow meter 3 can be realized. For example, the ideal installation state may be a state in which the required straight pipe length is secured before and after the flow meter 3. Therefore, regardless of the state of the air conditioning equipment 100, the measurement accuracy of the flow rate can always be secured.

The upstream side of the pump 4 is connected to the downstream side of the flowmeter 3. The downstream side of the pump 4 is connected to the liquid supply unit 7. The pump 4 increases or decreases the discharge flow rate in response to a control signal supplied from the control unit 8. The pump 4 may be one capable of adjusting the flow rate. The pump 4 may also be inverter controllable, and the output flow rate is controlled by the control signal supplied from the control unit 8. The pump 4 is not limited to one capable of adjusting the flow rate. For example, the flow rate adjustment configuration may include a pump that discharges a constant flow rate and an additional element that is added to the pump. The additional element may be, for example, an automatic two-way valve or a bypass flow path. The bypass flow path is a flow path that bypasses the upstream and downstream sides of the pump and has an adjustment valve provided in the bypass flow path.

The liquid supply unit 7 supplies water to the air conditioning equipment 100. The liquid supply unit 7 has a supply end 7a, and is connected to the air conditioning equipment 100 via this supply end 7a. Specifically, it is connected to the upstream side of the air conditioning unit 103. In the configuration illustrated in FIG. 3, it is connected to the valve 106. The liquid supply unit 7 may be directly connected to the air conditioning equipment 100, similar to the liquid recovery unit 2, or may be connected via a component such as a high-pressure hose 15. The liquid supply unit 7, similar to the liquid recovery unit 2, is attached to the air conditioning equipment 100 in step S1, which will be described later. Then, it is removed from the air conditioning equipment 100 in step S3, which will be described later. Therefore, the liquid supply unit 7 has a configuration that is detachable from the air conditioning equipment 100.

As shown in FIG. 4, the control unit 8 has, as functional components, a flow rate acquisition unit 8a, a differential pressure acquisition unit 8b, a data recording unit 8c, a pump control unit 8d, and a flow rate input unit 8e.

The flow rate acquisition unit 8a receives information about the flow rate (information φ3) from the flow meter 3 that constitutes the differential pressure measurement device 1, or information about the flow rate from a flow meter that does not constitute the differential pressure measurement device 1. In other words, the flow rate acquisition unit 8a only needs to be able to acquire information about the flow rate, and the configuration of the device that actually measures the flow rate (flow meter) does not matter.

The differential pressure acquisition unit 8b receives the differential pressure between two points at the design flow rate. The differential pressure acquisition unit 8b receives information φ13, φ104 related to the differential pressure from either or both of the differential pressure gauge 104 constituting the air conditioning equipment 100 and the differential pressure gauge 13 constituting the differential pressure measuring device 1. In other words, the differential pressure acquisition unit 8b only needs to be able to acquire the differential pressure at the design flow rate, and the configuration of the device that actually measures the differential pressure (differential pressure gauge) is not important. For example, when using the differential pressure gauge 13 constituting the differential pressure measuring device 1, it is possible to obtain the differential pressure even if the differential pressure gauge 104 constituting the air conditioning equipment 100 is not installed.

The data recording unit 8c stores the design flow rate and the value (differential pressure) acquired by the differential pressure acquisition unit 8b in association with each other. This function is realized by the flow rate acquisition unit 8a, the differential pressure acquisition unit 8b, and the data recording unit 8c.

The pump control unit 8d uses the value supplied from the flow meter 3 to control the pump 4 so that the flow rate output from the pump 4 becomes the design flow rate. For example, the pump control unit 8d is a PID controller. This function of controlling the flow rate is realized by the flow rate acquisition unit 8a and the pump control unit 8d.

The flow rate input unit 8e accepts data related to the design flow rate. For example, the flow rate input unit 8e may be an input device such as a keyboard, a touch panel, or a dial, or may be an information reading device such as a memory card reader or a CD drive that reads an information medium on which data is recorded. It may also be a device that receives data from the outside via wired or wireless communication. In FIG. 4, the flow rate input unit 8e is illustrated as one element of the control unit 8, but the flow rate input unit 8e may be configured as one element of the control unit 8, or may be configured as an element separate from the control unit 8.

Next, a method for obtaining a pressure difference in the air conditioning equipment 100 will be described. First, the recovery end 2a of the liquid recovery unit 2 is connected to the valve 107 (step S1a). Furthermore, the supply end 7a of the liquid supply unit 7 is connected to the valve 106 (step S1b). Note that step S1b may be performed first, followed by step S1a. In this embodiment, the valve 107 is a liquid receiving unit, and the valve 106 is a liquid discharging unit. Note that the position at which the supply end 7a and the recovery end 2a are connected is not limited to the valves 106, 107. In other words, the liquid receiving unit and the liquid discharging unit are not limited to the valves 107, 106, and may be other parts of the air conditioning equipment 100. Other connection configurations will be described later as Modification 1.

Next, the differential pressure measuring device 1 uses the differential pressure acquisition unit 8b to obtain the differential pressure between the two points when water is supplied to the measurement target portion 10C at the design flow rate (step S2, second step).

First, the differential pressure measuring device 1 supplies water at the design flow rate to the air conditioning equipment 100 (step S2a). Specifically, the control unit 8 controls the pump 4 based on the value of the flow meter 3 so that the flow rate of water output from the pump 4 becomes the design flow rate. This control is performed automatically, for example, using a PID controller. In other words, the differential pressure measuring device 1 automatically converges the flow rate of water output from the pump 4 to the design flow rate without requiring adjustment by an operator (see the period T1 to T2 in FIG. 6).

When performing step S2a, if the air conditioning equipment 100 is equipped with multiple heat exchange units 111, 112, and 113, and the multiple heat exchange units 111, 112, and 113 are operable when step S2 is performed, the flow control valve 113b connected to the heat exchange unit 113 to which water should be supplied is opened, and the flow control valves 111b and 112b connected to the other heat exchange units 111 and 112 are closed.

The open state is preferably a fully open state. In this case, a differential pressure setting value can be obtained that can reduce the power required for the pump unit 101.

Next, the differential pressure measuring device 1 measures the differential pressure (step S2b). This operation is executed by the differential pressure acquiring unit 8b. The differential pressure measured here is the pressure difference between two points in a path including the heat exchange unit 113 when the design flow rate is supplied to the heat exchange unit 113. When the design flow rate is supplied to the heat exchange unit 113, the pressure difference between two points in a path including the heat exchange unit 113 is the differential pressure of the air conditioning equipment 100 in this embodiment. The part that is the target of the differential pressure measurement in this step S2b is called the measurement target part 10C. Specifically, the measurement target part 10C refers to the part between two points that is set to include the heat exchange unit 113.

Here, the transport energy can be kept low by making the interval between the two points where the differential pressure used for the terminal differential pressure control is measured as short as possible. In order to supply a sufficient flow rate to the heat exchanger 113, it is necessary to maintain the differential pressure between two points on the piping path including the heat exchanger 113 and the flow control valve 113b that controls the flow rate to the heat exchanger 113. Therefore, it is preferable to measure the differential pressure between two points in the shortest interval including only the heat exchanger 113 and the flow control valve 113b. Therefore, a measurement target system including the heat exchanger 113 and the flow control valve 113b is set as the measurement target section 10C. And, unlike the connection position of the differential pressure gauge 13 shown in FIG. 3, the upstream side of the differential pressure gauge is connected between the valve 113a and the heat exchanger 113, and the downstream side is connected between the flow control valve 113b and the recovery branch section 143. This connection configuration makes it possible to obtain a pressure difference between two points on a piping path that includes only the heat exchanger 113 and the flow control valve 113b, and it is possible to simultaneously supply a sufficient flow rate required by the heat exchanger 113 and save energy.

The measurement target portion 10C may include components other than the heat exchange portion 113 and the flow control valve 113b, as long as it is a portion between two points that is set to include the heat exchange portion 113. For example, the measurement target portion 10C may include the heat exchange portion 113, the valve 113a, and the flow control valve 113b. Furthermore, the measurement target portion 10C may include the heat exchange portion 113, the valve 113a, the flow control valve 113b, the supply branch pipe 133, and the recovery branch pipe 153.

Furthermore, in the pipeline configuration shown in FIG. 3, when the information indicated by the differential pressure gauge 104 is obtained, the information includes the pressure loss from the supply branch 124 to the supply branch 123 of the supply main pipe 120, the pressure loss in the supply branch pipe 133, the pressure loss in the heat exchange section 113, the pressure loss in the recovery branch pipe 153, and the pressure loss from the recovery branch 143 to the recovery branch 144 of the recovery main pipe 140. In other words, the differential pressure in this embodiment may include the pressure loss in the supply main pipe 120 and the recovery main pipe 140 in addition to the narrow differential pressure (pressure loss in the supply branch pipe 133, pressure loss in the heat exchange section 113, and pressure loss in the recovery branch pipe 153).

Note that the path used to measure the differential pressure in this embodiment does not strictly match the path that is the subject of control when the air conditioning equipment 100 is in operation. However, if the flow rate matches the design flow rate, the same differential pressure value is obtained as when the pump unit 101 of the air conditioning equipment 100 is used at the measurement position. In other words, the relationship between the flow rate and differential pressure obtained in the embodiment can be reproduced in the path that is the subject of control when the air conditioning equipment 100 is in operation.

By making the connection position of the differential pressure gauge 13 for the heat exchange section that is the subject of differential pressure control the same as the connection position of the differential pressure gauge (e.g., differential pressure gauge 104) used when the air conditioning equipment 100 is in operation, a differential pressure set value useful for controlling the air conditioning equipment 100 after completion can be obtained. In other words, by making the measurement position of the differential pressure in step S2 (the position connecting the upstream end and downstream end of the differential pressure gauge 13) the differential pressure measurement position for controlling the air conditioning equipment, a differential pressure (differential pressure set value) useful for controlling the air conditioning equipment 100 after completion can be obtained. In other words, by using the differential pressure at the same position as the measurement subject section 10C for controlling the air conditioning equipment 100, the above-mentioned control effect can be obtained.

Even when measurements are taken at the same position and with the same flow rate, there may be a difference between the differential pressure measured by the differential pressure measuring device 1 and the differential pressure measured by the permanent differential pressure gauge 104 used for actual control due to mechanical differences and errors in the sensors. In such cases, the differential pressure setting value can be corrected by comparing the measured values of both.

As shown in FIG. 5, the design flow rate set in step S2 is not limited to one. For example, the differential pressure for each of the different design flow rates may be measured. In this case, the control unit 8 holds a plurality of different design flow rate values input by the flow rate input unit 8e. The step of inputting the design flow rate may be performed at any timing before step S2. For example, it may be performed before step S1, may be performed simultaneously with step S1, or may be performed after step S1 and before step S2. Then, after step S2b, a step of changing the design flow rate (step S2c) is performed. A first differential pressure when the design flow rate is the first is obtained (see period T2 in FIG. 6). Next, the first design flow rate is changed to the second design flow rate (step S2c). Then, a second differential pressure when the design flow rate is the second is obtained (see period T3 in FIG. 6). Furthermore, a third differential pressure when the design flow rate is the third is obtained (see period T4 in FIG. 6). In this way, the differential pressure when the design flow rate is the design flow rate may be measured while changing the value of the design flow rate.

In the above example, in periods T3 and T4, the differential pressure is obtained when the design flow rate is changed to a predetermined value. For example, in periods T3 and T4, the differential pressure may be measured at a flow rate that is a predetermined value lower than the first design flow rate (for example, a flow rate that is 90% of the first flow rate or 80% of the first flow rate).

After the measurement is completed, the differential pressure measuring device 1 is removed from the air conditioning equipment 100 (step S3: third step). First, the recovery end 2a of the liquid recovery unit 2 is removed from the valve 107 (step S3a). Furthermore, the supply end 7a of the liquid supply unit 7 is removed from the valve 106 (step S3b). By carrying out the above steps S1 to S3, the differential pressure of the air conditioning equipment 100 can be obtained. Note that step S3b may be carried out first, followed by step S3a.

In the method for obtaining the differential pressure of the air conditioning equipment 100 according to the embodiment, the differential pressure measuring device 1 equipped with the pump 4, the flow rate acquiring unit 8a, and the differential pressure acquiring unit 8b is connected to the measurement target unit 10C including the heat exchange unit 113 via the liquid recovery unit 2 and the liquid supply unit 7. In other words, in order to obtain the differential pressure (the differential pressure set value which is the target value for differential pressure control), it is sufficient that only the heat exchange unit 113 and the flow rate control valve 113b which are the measurement targets are prepared, and the construction state of the air conditioning equipment 100 including the heat exchange unit 113 does not matter. As a result, this method can be performed after the construction of the air conditioning equipment 100 including the heat exchange units 111, 112, and 113 is completed, or, for example, it can be performed in a state where only the heat exchange unit 113 and the flow rate control valve 113b which are the measurement targets are arranged in the building. Furthermore, it does not even matter whether the heat exchange unit 113 and the flow rate control valve 113b are arranged in the building. Therefore, the timing for obtaining the differential pressure of the air conditioning equipment 100 can be flexibly set.

In other words, the method and differential pressure measuring device 1 of this embodiment can obtain the differential pressure before flushing the cold water system and the hot water system. This makes it possible to shift the peak load in the construction work, which is called labor reduction.

Furthermore, the differential pressure measuring device 1 automatically causes the flow rate supplied to the air conditioning equipment 100 to converge to the design flow rate by the control unit 8. This allows for automation of the work, thereby reducing the labor required to obtain the differential pressure. Furthermore, since the supply of the design flow rate and the acquisition of the differential pressure at that time are performed automatically, the operator is not required to have a high level of knowledge and experience. Therefore, a highly reliable differential pressure of the air conditioning equipment 100 can be obtained without being influenced by the operator's ability. Furthermore, it is possible to obtain the differential pressure for each of several different design flow rates. As a result, it is also possible to obtain basic data for energy saving proposals, such as changing the set value of the differential pressure according to the load factor. Ultimately, the operating efficiency of the air conditioning equipment 100 can be improved.

The above describes an embodiment of the present invention, but the present invention may be implemented in various forms without being limited to the above embodiment.

[Modification 1]
In the embodiment, the supply end 7a of the liquid supply unit 7 is connected to the valve 106, and the recovery end 2a of the liquid recovery unit 2 is connected to the valve 107. In this connection configuration, the liquid supply unit 7 is connected to the measurement target unit 10C via the supply main pipe 120, and the liquid recovery unit 2 is connected to the measurement target unit 10C via the recovery main pipe 140. For example, as shown in FIG. 7, the liquid supply unit 7 and the liquid recovery unit 2 may be connected to a position closer to the measurement target unit 10C. Specifically, the supply end 7a of the liquid supply unit 7 may be connected to the supply branch 123 of the supply main pipe 120, and the recovery end 2a of the liquid recovery unit 2 may be connected to the recovery branch 143 of the recovery main pipe 140. That is, in the first modification, the supply branch 123 is a liquid receiving unit, and the recovery branch 143 is a liquid discharging unit.

In this connection configuration, the differential pressure may be measured using a differential pressure gauge 104 that constitutes the air conditioning equipment 100. As shown in FIG. 7, a differential pressure gauge 13 that constitutes the differential pressure measuring device 1 may also be used. The temporary differential pressure gauge 13 may be connected on its upstream side to the supply branch section 123 and on its downstream side to the recovery branch section 143. The work of connecting the differential pressure gauge 13 may be performed, for example, as part of the process (S1) of installing the differential pressure measuring device 1. Furthermore, it may be performed as part of the process (S2) of measuring the differential pressure.

As described above, this connection configuration makes it possible to make the distance between the two points for measuring the differential pressure used in the terminal differential pressure control as short as possible, and by appropriately using the differential pressure measured in this way to control the air conditioning equipment 100, the transport energy of the air conditioning equipment 100 can be kept low. In other words, by measuring the differential pressure between the two shortest points necessary, it is possible to obtain a differential pressure (differential pressure set value) that is effective in reducing the transport energy of the air conditioning equipment 100.

[Modification 2]
In the embodiment, the measurement target 10C is set as a measurement system including a heat exchanger 113 included in the path with the highest piping resistance. For example, the heat exchanger 113 may supply air to a space such as a locker room or a storeroom, and the heat exchanger 111 included in the path with the second highest piping resistance may supply air to a space such as a reception room. In this case, the heat exchanger 111 is more likely to supply air that is more precisely adjusted than the heat exchanger 113. Therefore, as shown in FIG. 8, the heat exchanger 111 may be included in the measurement target 10A.

In this case, the supply end 7a of the liquid supply section 7 is connected to the supply branch section 121 of the main supply pipe 120, and the recovery end 2a of the liquid recovery section 2 is connected to the recovery branch section 141 of the main recovery pipe 140. The temporary differential pressure gauge 13 is connected on its upstream side to the supply branch section 121 and on its downstream side to the recovery branch section 141. In other words, in the second modification, the supply branch section 121 is the liquid receiving section, and the recovery branch section 141 is the liquid discharging section.

By appropriately using the differential pressure measured using this connection configuration to control the air conditioning equipment 100, it is possible to provide the required air conditioning for rooms that require highly accurate air conditioning control. In other words, it is possible to obtain a differential pressure (differential pressure setting value) that is effective in ensuring the accuracy of air conditioning control.

[Modification 3]
In the embodiment, as shown in (a) of FIG. 9, the measurement target section 10C is described as including one heat exchange section 113, a valve 113a, and a flow control valve 113b. For example, as shown in (b) of FIG. 9, the measurement target section 10CA may include two or more heat exchange sections 113 and 114, and the valves 113a and 114a and the flow control valves 113b and 114b associated with each of them. The upstream sides of the heat exchange sections 113 and 114 are connected to each other in parallel via branch pipes 133a and 133b. The branch pipes 133a and 133b are connected to the supply branch section 123 of the supply main pipe 120 via the supply branch pipe 133. The downstream sides of the heat exchange sections 113 and 114 are connected to each other in parallel via branch pipes 173a and 173b. Similarly, the branch pipes 173a and 173b are connected to the recovery branch 143 of the main recovery pipe 140 via the recovery branch 153. When measuring the differential pressure of the measurement target section 10CA, the upstream side of the differential pressure gauge 13 is connected to the supply branch 123, and the downstream side is connected to the recovery branch 143. The upstream side of the differential pressure gauge 13 may be connected to a branch (not shown) provided in the supply branch 133, and the downstream side of the differential pressure gauge 41 may be connected to a branch (not shown) provided in the recovery branch 153.

In addition, in a connection configuration similar to that shown in FIG. 9(b), as shown in FIG. 9(c), the heat exchanger 113, the valve 113a, and the flow control valve 113b may be one measurement target part 10CB, and the heat exchanger 114, the valve 114a, and the flow control valve 114b may be another measurement target part 10CC.

When measuring the differential pressure of the measurement target section 10CB, the differential pressure gauge 13A is connected on its upstream side to the branch line 133a extending from the supply branch pipe 133 to the valve 113a. The differential pressure gauge 13A is also connected on its downstream side to the branch line 173a extending from the recovery branch pipe 153 to the flow control valve 113b. On the other hand, when measuring the differential pressure of the measurement target section 10CC, the differential pressure gauge 13B is connected on its upstream side to the branch line 133b extending from the supply branch pipe 133 to the valve 114a. The differential pressure gauge 13B is also connected on its downstream side to the branch line 173b extending from the recovery branch pipe 153 to the flow control valve 114b.

By measuring the differential pressure of such measurement targets, it is possible to reduce the amount of work required by measuring multiple heat exchangers all at once, rather than measuring each one individually, in cases where it is clear from specifications, etc. that the equipment has the same characteristics. Also, in cases where it is difficult to measure one unit at a time due to factors such as the on-site piping route, it is possible to measure and control multiple units at once instead.

[Modification 4]
For example, as shown in Fig. 10, the method and device of this embodiment may be applied to an air conditioning system 100A equipped with multiple air conditioning units 103A, 103B, and 103C. As described above, the method and device of this embodiment can automatically obtain the differential pressure of each of the air conditioning units 103A, 103B, and 103C. Therefore, it is possible to perform the work of obtaining the differential pressure of the air conditioning units 103A, 103B, and 103C more quickly, which further contributes to labor saving. Furthermore, when measurements are required at many points, the measurement work increases and the adjustment of the process becomes difficult, so the effect of being able to perform measurements easily and flexibly at the right time using the differential pressure measuring device 1 is great.

Although the embodiment and the modified examples have been described above, the differential pressure measuring device 1 is not limited to the configurations of the embodiment and the modified examples. In the above embodiment and modified examples 1 and 2, the valve 107 and the supply branching parts 123 and 121 are exemplified as examples of the liquid receiving part. In addition, the valve 106 and the recovery branching parts 143 and 141 are exemplified as examples of the liquid recovery part. However, the liquid receiving part and the liquid recovery part in the embodiment and each modified example are not limited to these configurations. As the liquid receiving part, a part capable of supplying liquid to the measurement target part in the air conditioning equipment 100 may be selected. For example, a branching part (not shown) provided in the supply branching pipe 133 for the measurement target part 10C may be used as the liquid receiving part. Similarly, as the liquid discharge part, a part capable of discharging liquid from the measurement target part in the air conditioning equipment 100 may be selected. For example, a branching part (not shown) provided in the recovery branching pipe 153 for the measurement target part 10C may be used as the liquid receiving part. The above-described settings for the liquid receiving section and liquid recovery section can be applied to any of the embodiments and modified examples.

For example, the housing housing the flowmeter 3, pump 4, liquid recovery unit 2, and liquid supply unit 7 may not include the control unit 8, and the housing housing the flowmeter 3, pump 4, liquid recovery unit 2, and liquid supply unit 7 may be connected to the control unit 8 via a wired or wireless connection. Also, the flowmeter 3, pump 4, liquid recovery unit 2, liquid supply unit 7, etc. may not be housed in a housing. For example, they may be placed on a cart. In other words, the differential pressure measuring device 1 only needs to have the pump 4, liquid recovery unit 2, liquid supply unit 7, control unit 8, etc. connected so as to perform their functions.

For example, although the description has been given of a case in which the flow rate of water output from pump 4 is automatically controlled to be the design flow rate, this can also be substituted as appropriate by manually adjusting it using a flow control valve, etc.

1...differential pressure measuring device, 2...liquid recovery section, 2a...recovery end, 4...pump, 7...liquid supply section, 7a...supply end, 8...control section, 8a...flow rate acquisition section, 8b...differential pressure acquisition section, 8c...data recording section, 8d...pump control section, 10A, 10C, 10CA, 10CB, 10CC...measurement target section, 12a...air vent valve, 12b...water vent valve, 15...high pressure hose, 100, 100A...air conditioning equipment, 101...pump unit, 102...flow rate measurement unit, 103, 103A, 103B, 103C...air conditioning section, 105, 106, 107, 113a, 114a...valve, 111b, 112b, 113b, 114b...flow control valve, 120...supply main pipe, 121, 122, 123, 124, 125...supply branch section, 131, 132, 133, 134, 135...supply branch pipe, 140...recovery main pipe, 141, 142, 143, 144, 145...recovery branch section, 151, 152, 153, 154, 155...recovery branch pipe, 111, 112, 113, 114...heat exchange section, 101a, 102a...connection section, 133a, 133b, 173a, 173b...branch pipe, 200...heat source equipment, 300...control device.

Claims (3)

A method for obtaining a differential pressure in an air conditioning system, comprising:
a liquid recovery unit that recovers the liquid discharged from the measurement target unit; a differential pressure gauge that obtains a pressure difference between the liquid supplied from the liquid supply unit and the liquid recovered from the liquid recovery unit as a differential pressure; and a differential pressure acquisition unit that receives the differential pressure obtained by the differential pressure gauge as information regarding the differential pressure in the measurement target unit, comprising: a first step of connecting the liquid supply unit to the upstream side of the measurement target unit and connecting the liquid recovery unit to the downstream side of the measurement target unit;
a second step of receiving, using the differential pressure acquisition unit, information regarding the differential pressure in a state in which the liquid is supplied from the liquid supply unit to the measurement target unit at a predetermined flow rate and the liquid that has flowed out of the measurement target unit is recovered by the liquid recovery unit;
and a third step of removing the liquid supply unit and the liquid recovery unit from the measurement object. The second step comprises:
Varying the value of the predetermined flow rate;
and obtaining said differential pressure after said modification. A device for obtaining a pressure difference in an air conditioning system,
a liquid supply unit that supplies a predetermined flow rate of liquid to a measurement target unit configured by a component included in the air conditioning equipment;
a liquid recovery unit that recovers the liquid discharged from the measurement target unit;
a differential pressure gauge that obtains a pressure difference between the liquid supplied from the liquid supply unit and the liquid recovered from the liquid recovery unit as a differential pressure;
a differential pressure acquisition unit that receives information regarding the differential pressure in the measurement target portion from the differential pressure gauge when the liquid supplied from the liquid supply unit is circulating at the specified flow rate and the liquid that has flowed out of the measurement target portion is being recovered by the liquid recovery unit.

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