JP7201450B2 - Constant temperature and high humidity storage - Google Patents

Description

The technology disclosed in this specification relates to a constant temperature and high humidity chamber and its operating method.

A constant temperature and high humidity storage is known as a storage that can store fresh food for a long period of time without drying it. For example, in the constant temperature and high humidity storage disclosed in Patent Document 1 below, a space formed between a box having heat insulating walls and a storage room in which food or the like is stored is a cooling duct (referred to as a cold air duct). It is used as a Cold air is supplied from a cold air supply device to the cooling duct to cool the wall surface of the storage compartment, thereby indirectly cooling the inside of the storage compartment (so-called indirect cooling method).

A cold air supply device provided in the constant temperature and high humidity chamber may have a known configuration in which a compressor, a condenser, a cooler, etc. are circulated and connected by refrigerant pipes containing a refrigerant. The condenser is provided with a condenser fan for air-cooling the condenser whose temperature is increased by the heat of condensation generated when the refrigerant is liquefied and condensed. A duct fan is also provided within the cooling duct to create a circulating airflow through the cooler. When the compressor, condenser fan and duct fan are driven, air in the cooling duct is drawn through the cooler. Cold air generated by heat exchange while passing through the cooler is discharged toward the cooling duct, thereby indirectly cooling the inside of the storage chamber as described above.

Conventionally, a constant-speed compressor has been used as the compressor, and by driving/stopping this compressor, the temperature in the storage chamber has been kept substantially constant. That is, the operation of the cool air supply device is controlled by starting the compressor when the internal temperature is higher than the internal temperature set value by a predetermined value or more, and by stopping the compressor when the internal temperature is lower than the predetermined value or more.

JP-A-05-264158

For example, as described above, if the cold air supply device is controlled by driving/stopping the constant speed compressor, the cooling capacity changes binary depending on whether the compressor is driven or not, so the duct temperature in the cooling duct fluctuates greatly. However, along with this, fluctuations in the internal temperature of the storage chamber also increase. In order to preserve perishable food while maintaining its freshness, it is desirable to keep the internal temperature as constant as possible and reduce temperature variations within the storage compartment.

The technology disclosed in the present specification was completed in consideration of the above circumstances and the like, and aims to effectively suppress fluctuations in the temperature inside the storage compartment (internal temperature) in a constant temperature and high humidity storage. .

(1) The constant-temperature and high-humidity storage disclosed by the present specification includes a heat-insulating box body having heat-insulating walls, and a cooling duct serving as a cold air passage between the heat-insulating box body and the heat-insulating box body. An inner box with a storage chamber inside, a condenser, a cooler, and a variable rotation speed compressor are circulatingly connected by refrigerant pipes containing refrigerant to supply cold air into the cooling duct. a cold air supply device that indirectly cools the inside of the storage chamber by doing so, a duct temperature sensor that measures the duct temperature in the cooling duct at predetermined sampling times regardless of the driving state of the compressor, and the storage chamber storage means for storing a cooling characteristic indicating a change over time of a duct temperature target value, which is a target for the duct temperature for making the inside temperature of the refrigerator equal to the preset inside temperature set value; and the duct temperature computing means for calculating a target rotation speed of the compressor for decreasing the duct temperature in accordance with the cooling characteristic based on the duct temperature measurement value measured by the sensor; and a compressor drive means that varies according to the number.

According to the above configuration, by applying a variable rotation speed compressor to an indirect cooling type constant temperature and high humidity chamber and controlling the inverter, the constant speed compressor is driven/stopped to control the temperature. Cooling capacity can be finely adjusted compared to damp storage. Here, in the constant temperature and high humidity warehouse of the indirect cooling method, instead of directly supplying cold air from the cold air supply device into the storage room, the cold air in the cooling duct cools the wall surface of the inner box, thereby increasing the internal temperature. It is lowered indirectly. In other words, it is the duct temperature, not the inside temperature, that is directly affected and fluctuates first when the rotation speed of the compressor is changed. Therefore, instead of controlling the compressor based on the internal temperature like the conventional direct cooling type constant temperature storage equipped with an inverter compressor, the rotation speed of the compressor is controlled based on the duct temperature as in the above configuration. If it is changed, it is possible to further enhance dependence on the target temperature change mode. In addition, by continuing to measure the duct temperature at predetermined sampling times including when the compressor is stopped, for example, the timing at which the compressor should be restarted can be detected as early as possible. As a result, it is possible to effectively suppress temperature fluctuations in the storage compartment of the constant temperature and high humidity storage.

(2) Further, in the constant temperature and high humidity chamber disclosed by the present specification, in the above (1), the storage means stores temperature-related data representing the relationship between the temperature inside the chamber and the temperature of the duct. The calculation means may calculate the duct temperature target value from the internal temperature setting value based on the temperature-related data.
In such a configuration, the temperature-related data can be calculated from past actual measurements, etc., in consideration of the size (capacity), arrangement, structure, performance, etc. of related devices and members. According to the above configuration, it is possible to appropriately determine the duct temperature target value by determining the duct temperature target value required to realize the chamber internal temperature set value based on such temperature-related data. .

(3) In the constant temperature and high humidity chamber disclosed by the present specification, in the above (1) or (2), the cooling characteristic is a target for the duct temperature drop rate defined according to the duct temperature and the calculating means may calculate the target rotation speed for achieving the duct temperature drop rate target value based on the duct temperature measurement value .
According to such a configuration, it is possible to more easily and quickly calculate the target rotational speed of the compressor according to the duct temperature measurement value.

(4) Further, in the constant temperature and high humidity chamber disclosed by the present specification, in the above (3), the calculation means includes the duct temperature and the compressor drive means operates the compressor when the measured duct temperature exceeds a duct temperature upper limit value that is higher than the duct temperature index value by a predetermined value. and stopping the compressor when the duct temperature measurement value becomes lower than the duct temperature lower limit value lower than the duct temperature index value by a predetermined value, and the duct temperature drop rate target value is set to the duct temperature index value. is a positive value in a first control temperature region that is equal to or higher than the duct temperature intermediate value higher than the duct temperature lower limit value and equal to or lower than the duct temperature upper limit value, and is less than the duct temperature intermediate value and equal to or higher than the duct temperature lower limit value may be a negative value in the second control temperature region of .
According to such a configuration, when the duct temperature measurement value drops to the duct temperature intermediate value, the compressor rotation speed is positively corrected by the compressor rotation speed control means so that the cooling capacity is reduced. descend. This allows the duct temperature measurement to drop less to the lower limit and the compressor to run continuously for a longer period of time. As a result, the increase in temperature inside the storage compartment due to the stoppage of the compressor is reduced, and temperature fluctuations in the storage compartment are suppressed.

(5) Further, the constant temperature and high humidity storage disclosed by the present specification, in any one of (1) to (4) above, includes an internal temperature sensor provided in the storage chamber for measuring the internal temperature. and an ambient temperature sensor provided outside the heat insulating box for measuring ambient temperature, wherein the storage means stores the measured value of the duct temperature and the internal temperature measured by the internal temperature sensor. and data for estimating the central temperature in the central part of the storage chamber from the ambient temperature measured value measured by the ambient temperature sensor. From the duct temperature measurement value, the internal temperature measurement value, and the ambient temperature measurement value, the internal temperature is estimated based on the central temperature estimation data, and the internal internal temperature is set in advance. A duct temperature index value that is a target of the duct temperature for setting the internal temperature setting value may be calculated.
According to such a configuration, the internal temperature in the central part of the storage chamber is inferred from the internal temperature measured by the internal temperature sensor installed at the specific location, and this internal internal temperature is the internal temperature set value. is controlled to be Therefore, it is possible to maintain the entire storage chamber near the internal temperature set value, taking into account variations in temperature (inside temperature) in the storage chamber.

(6) In addition, the constant temperature and high humidity storage disclosed by the present specification further includes incidental equipment capable of influencing the temperature inside the storage according to the state in the above (5), and the storage means includes the Supplementary data about the influence of the condition of ancillary equipment on the inside central temperature is further stored, and the computing means calculates the duct temperature measurement value, the inside temperature measurement value, the ambient temperature measurement value, and the The internal central temperature may be estimated based on the data for estimating the central temperature and the incidental data from the information about the state of the incidental equipment.
According to such a configuration, for example, the dew condensation prevention heater is attached to the heat insulating door or the heat insulating box body, and in a constant temperature and high humidity store where the inside temperature fluctuates depending on the energization state of these heaters, the storage room can be stored with higher accuracy. It becomes possible to maintain the whole in the vicinity of the internal temperature setting value.

(7) In addition, the method for operating a constant temperature and high humidity warehouse disclosed by the present specification includes forming a heat insulating box body having heat insulating walls and a cooling duct serving as a cold air passage between the heat insulating box body, The cooling duct in which an inner box arranged inside the heat insulating box and having an interior serving as a storage room, a condenser, a cooler, and a variable rotation speed compressor are circulated and connected by a refrigerant pipe containing a refrigerant. a cold air supply device that indirectly cools the inside of the storage chamber by supplying cold air to the interior of the storage chamber; and storage means for storing a cooling characteristic indicating the change over time of the duct temperature target value as a target for Measure the duct temperature in the cooling duct for each sampling time, calculate the target rotation speed of the compressor for decreasing the duct temperature according to the cooling characteristic based on the duct temperature measurement value, is a method of operating a constant temperature and high humidity chamber, in which the number of rotations of is changed in accordance with the target number of rotations.
According to such a configuration, the constant temperature and high humidity storage can be operated while effectively suppressing temperature fluctuations in the storage compartment.

According to the technique disclosed by this specification, the temperature change in the storage room in a constant temperature and high humidity storage can be suppressed.

Partial exploded perspective view of a constant temperature and high humidity chamber according to one embodiment Longitudinal cross section of constant temperature and high humidity chamber Partially enlarged view of FIG. 2 in the vicinity of the cold air supply device Block diagram showing the mechanism related to the operation control of the constant temperature and high humidity chamber Flowchart showing an example of the operation of a constant temperature and high humidity chamber Flowchart showing an example of temperature control operation of constant temperature and high humidity storage Timing chart showing an example of temperature control for constant temperature and high humidity storage

<Embodiment>
A constant temperature and high humidity chamber according to one embodiment will be described below with reference to the drawings.
In the following explanation, the front left side of the paper in FIG. ). In addition, with respect to a plurality of identical members, one member may be given a reference numeral, and the other members may be omitted. Further, parameters such as temperatures, which will be described later, may be indicated by adding s to set values or index values, t to target values, and m to measured values.

[Schematic configuration of constant temperature and high humidity storage]
As shown in FIGS. 1 to 3, in this embodiment, a four-door commercial constant temperature and high humidity warehouse 1 is exemplified. As shown in FIG. 1 and the like, the constant temperature and high humidity chamber 1 includes an insulation box (insulation box body) 10 having insulation walls, a machine room 20 arranged above the insulation box 10, and the insulation box 10. and an inner box 30 which is housed inside and whose inside is a storage room 30S. As shown in FIG. 2 and the like, the heat insulating box 10 has a box-like shape with a forward opening. A cross-shaped heat-insulating partition frame 19 is attached to the front opening of the heat-insulating box 10 to form a total of four opening areas. As shown in FIG. 1 and the like, a heat insulating door 18 with a packing attached to the back surface is attached to these opening regions so as to be openable and closable. As a result, the storage room 30</b>S can be opened and closed by the heat insulating door 18 . Inside the storage room 30S, a shelf network 31 for arranging stored items (food etc.) over a plurality of stages is arranged.

Specifically, the heat insulating box 10 includes an outer box 11 made of a metal plate, an inner box 12 made of a metal plate and housed inside the outer box 11 with a space therebetween, and a space between the outer box 11 and the inner box 12. and a heat insulating material 13 filled in. The interior box 30 that defines the storage room 30S is formed by combining a plurality of metal plates with good thermal conductivity such as stainless steel plates, and has a box shape that opens forward. The inner box 30 is one size smaller than the inner box 12 of the heat insulating box 10, and is housed inside the heat insulating box 10 with a certain space formed between itself and the inner box 12.例文帳に追加A space formed between the inner box 30 and the inner box 12 is a cooling duct 40D. The interior box 30 includes a bottom wall portion 30A forming the bottom surface of the storage chamber 30S, a back surface 30B, a ceiling wall portion 30C forming the ceiling, and a pair of left and right side wall portions. The aforementioned cooling duct 40D is formed outside the walls 30A, 30B, 30C, etc. of the interior box 30 so as to surround the storage chamber 30S above, left and right sides, below, and behind.

Specifically, the cooling duct 40D includes a first passage 41D, a second passage 42D, a third passage 43D, and a pair of fourth passages. As shown in FIG. 2, the first passage 41D is formed between the upward facing lower surface 12A of the inner surface of the heat insulating box 10 (inner box 12) and the outer surface of the bottom wall portion 30A, and the storage chamber 30S. This is the space arranged below the The second passage 42D is a space formed between the forward-facing rear surface 12B of the inner surface of the insulation box 10 and the outer surface of the rear wall portion 30B, and arranged behind the storage chamber 30S. The third passage 43D is a space formed between the downward facing upper surface 12C of the inner surface of the insulation box 10 and the outer surface of the ceiling wall portion 30C and arranged above the storage chamber 30S. Although not shown in the drawing, a fourth passage is formed between the side surface of the inner surface of the heat insulating box 10 facing the side and the pair of left and right side wall portions of the inner box 30, and is formed between the left and right side walls of the storage chamber 30S. It is a space arranged on the side. The inner surfaces (lower surface 12A, rear surface 12B, upper surface 12C, and side surfaces) of the heat insulating box 10 described above are made up of panel members forming the inner box 12. As shown in FIG.

A cold air supply device 21 is provided in the machine room 20 . The cold air supply device 21 includes a condenser 22 , a condenser fan 23 attached to the condenser 22 , and a compressor 24 . The compressor 24 is a rotation speed variable inverter compressor capable of controlling the rotation speed CR in a plurality of stages. As shown in the enlarged view of FIG. 3, the condenser 22, condenser fan 23, and compressor 24 are mounted on a heat-insulating base 26, and on the underside of the base 26 is a cooler 27. It is attached. As shown in FIG. 1, on the base 26, an electrical box (control box) 25 containing a control unit 100 for controlling the cool air supply device 21 and the like is also installed. An operation box 90 is installed in front of the machine room 20 . The operation box 90 has a target temperature setting unit 91 and an internal temperature display unit 92. On the front surface of the constant temperature and high humidity chamber 1, the internal temperature setting value TSs is input and set, and the internal temperature TS is confirmed. It is possible.

The base 26 is attached to the heat insulating box 10 so as to block the window hole 16A formed in the ceiling wall portion 16 of the heat insulating box 10 from above. An air duct 50 that also serves as a drain pan is provided in the ceiling wall portion 16 of the heat insulating box 10, and a cooler chamber 45D is formed above the air duct 50 in the cooling duct 40D. The cooler 27 is attached so as to protrude downward from the base 26 and is accommodated in the cooler chamber 45D. The cooler 27 is circulatingly connected to the cold air supply device 21 through a refrigerant pipe in which a refrigerant is sealed to form a well-known cooling cycle.

A suction port 50A is formed in the front portion of the air duct 50, and a blowout port 50B is formed in the rear portion thereof. A duct fan (cooling fan) 29 is attached to the suction port 50A. The cooler 27 and the duct fan 29 are arranged outside the inner box 30, more specifically above the inner box 30 (ceiling wall portion 30C). The duct fan 29 sucks the air in the third passage 43D into the cooler chamber 45D and supplies the air cooled by the cooler 27 to the second passage 42D.

When the duct fan 29 is driven while the compressor 24 and the condenser fan 23 of the cool air supply device 21 configured as described above are operated, the air in the third passage 43D of the cooling duct 40D is drawn by the duct fan 29 from the suction port 50A. The air is sucked into the cooler chamber 45</b>D and cooled by heat exchange when the air passes through the cooler 27 . The air (cold air) cooled by the cooler 27 is blown out from the outlet 50B to the second passage 42D behind the storage chamber 30S, and then directed to the first passage 41D below the storage chamber 30S. Then, after heading from the first passage 41D to the fourth passages on the left and right sides of the storage chamber 30S, it turns around from the fourth passages to the third passages 43D. Cool air is thus circulated and supplied in the cooling duct 40D. The cool air cools each wall (bottom wall 30A, side wall, rear wall 30B, ceiling wall 30C) of the inner box 30, thereby indirectly cooling the inside of the storage room 30S. be. Therefore, the inside of the storage room 30S is cooled to a predetermined temperature while maintaining high humidity.

As shown in FIGS. 1 and 3, etc., in the constant temperature and high humidity chamber 1 according to the present embodiment, a dew condensation prevention heater 70 is provided as accessory equipment for suppressing dew condensation that occurs near the opening on the front side of the insulation box 10. is provided. The condensation prevention heater 70 includes a main body side condensation prevention heater 70A provided along the front opening of the heat insulating box 10 and a door side condensation prevention heater 70B provided inside the heat insulating door 18 . As shown in FIG. 3, these dew condensation prevention heaters 70 can be made by embedding cord heaters in the heat insulating material filled inside the heat insulating box 10 or the heat insulating door 18, for example. . The manner in which the body-side condensation prevention heater 70A and the door-side condensation prevention heater 70B are arranged is not particularly limited. For example, in the present embodiment, as shown in FIG. 1, the main body side dew condensation prevention heater 70A is provided in the shape of one large rectangular frame along the front opening of the heat insulating box 10. For example, a cord heater is provided. It may also be embedded in the partition frame 19 and provided in the form of four rectangular frames individually surrounding each opening region. When these dew condensation prevention heaters 70 are energized, the internal temperature TS in the storage compartment 30S is affected by the heat emitted from them.

[Configuration related to temperature control of constant temperature and high humidity storage]
A configuration for suppressing fluctuations in the internal temperature TS in the storage compartment 30S and maintaining it substantially constant will be described.
As shown in FIG. 3, on the lower surface of the ceiling wall portion 30C of the inner box 30 forming the storage chamber 30S, that is, near the ceiling in the storage chamber 30S, there is an internal temperature for measuring the internal temperature TS. A sensor 81S is provided. A duct temperature sensor 81D for measuring the duct temperature TD is provided on the windward side of the cooler 27 in the cooler chamber 45D of the cooling duct 40D. Furthermore, although not shown in FIG. 3 and the like, an ambient temperature sensor 81A (see FIG. 4) for measuring the ambient temperature TA outside the heat insulation box 10 is provided on the substrate arranged inside the operation box 90. It is Also, although not shown in FIG. 3, a dew condensation prevention heater energization detection sensor (an example of an incidental equipment state detection sensor) 71 (see FIG. 4) is provided to The energized state of the prevention heater 70B is detected. In addition, as described above, the user inputs the chamber internal temperature setting value TSs from the target temperature setting section 91 (see FIGS. 1 and 4) provided in the operation box 90 .

As shown in FIGS. 4 to 6, the constant temperature and high humidity chamber 1 according to the present embodiment is temperature-controlled by a control section 100 having a microcomputer or the like and executing a predetermined program. Note that the microcomputer and the like, which are the main parts of the control unit 100, are housed in the electrical box 25 of the machine room 20 as described above.

As shown in the block diagram of FIG. 4, the temperature sensors 81D, 81S, 81A and dew condensation prevention heater energization detection sensor (an example of an accessory equipment state detection sensor) 71 are connected to the input side of the control unit 100. ing. Information about the energization state of the dew condensation prevention heater 70 is obtained by detecting it with the dew condensation prevention heater energization detection sensor 71 or the like as in the present embodiment. etc., it may be obtained directly. Furthermore, the target temperature setting unit 91 is configured to transmit the internal chamber temperature setting value TSs to the control unit 100 .

As shown in FIG. 4, the control unit 100 is provided with a clock unit 102 that emits a clock signal, and the inside temperature sensor 81S, the duct temperature sensor 81D, and the ambient temperature sensor 81A are connected to the input side. and the energized states of the body-side condensation prevention heater 70A and the door-side condensation prevention heater 70B detected by the condensation prevention heater energization detection sensor 71 are sent to the control unit 100 at regular sampling intervals. to be entered. Each value is input at a constant sampling time t regardless of the driving state of the compressor 24, that is, even while the compressor 24 is stopped while the constant temperature and high humidity chamber 1 is in operation. It is preferable that the sampling time t be a time width that is estimated to be optimal for monitoring from an average compressor start/stop cycle time calculated from the past operating results of similar constant temperature and high humidity warehouses.

The control unit 100 is also provided with a data storage unit (storage means) 103 . The data storage unit 103 stores a duct cooling characteristic (cooling characteristic) PD that indicates a change over time of a duct temperature target value TDt, which is a target for the duct temperature TD. The duct cooling characteristics PD are stored as a reference table created based on past actual measurement data, an arithmetic expression calculated based on past actual measurement data, etc., in consideration of the size (capacity) and performance of each device. can be made In this embodiment, as a cooling characteristic, a case where a reference table defining a duct temperature drop rate target value RDt according to a duct temperature TD is stored will be exemplified. Note that the duct temperature drop rate RD is defined as the drop amount ΔTD/Δt of the duct temperature TD per unit time.

In this embodiment, the data storage unit 103 provided in the control unit 100 further stores temperature-related data X, central temperature estimation data Y, and incidental data Z. FIG. The temperature-related data X is data indicating the relationship between the internal cold storage temperature TS and the duct temperature TD. The center temperature estimation data Y is data indicating the relationship between the duct temperature TD, the inside temperature TS, the ambient temperature TA, and the inside central temperature TSc, which is the temperature at the center of the storage chamber 30S. Supplementary data Z is data indicating the effect of the energization state of the dew condensation prevention heater 70 on the inside central temperature TSc. These data X, Y, and Z are, for example, the degree of influence each parameter has on the inside central temperature TSc, which is calculated based on past actual measurement data in consideration of the size (capacity) and performance of each related device. can be stored as a coefficient or the like representing Based on these data X, Y, Z, the measured duct temperature TDm, the measured internal temperature TSm, the measured ambient temperature TAm, and the energized state of the dew condensation prevention heater 70 are input to the control unit 100 at each sampling time. , the internal central temperature TSc can be inferred. In addition, since the inside of the storage room 30S is not forcibly ventilated or blown, the storage room The inside temperature TS increases toward the upper part of 30S. Since the internal temperature sensor 81S of the present embodiment is installed so that the temperature detection portion is located 2 cm or more below the ceiling wall portion 30C, the duct temperature measured value TDm<internal central temperature TSc<internal temperature measured value TSm<ambient temperature measured value TAm.

The control unit 100 is also provided with a calculation unit (calculation means) 104 that performs calculations using a microcomputer or the like. The calculation unit 104 calculates the duct temperature index value TDs and the like while referring to the respective data X, Y, and Z based on the in-chamber temperature setting value TSs input from the target temperature setting unit 91 . Also, based on the measured values TDm, TSm, TAm of the respective temperatures input from the respective temperature sensors 81D, 81S, 81A and the energized state of the dew condensation prevention heater 70, the duct cooling characteristics PD and the respective data X, Y, While referring to Z, the target rotational speed CRt of the compressor 24 and the like are calculated.

As shown in FIG. 4, a compressor 24 is connected to the output side of the control unit 100 via an inverter circuit (compressor driving means) 105, and the rotation speed CR can be set in multiple stages (for example, six stages). ) can be changed.

[An example of temperature control in a constant temperature and high humidity storage]
An example of control will be described with reference to the flow charts of FIGS. 5 and 6. FIG.
As shown in FIG. 5, when the constant temperature and high humidity chamber 1 is powered on and started, and the chamber temperature setting value TSs is input from the target temperature setting unit 91 (S1), the calculation unit 104 controls the chamber center A duct temperature index value TDs, which is an index for the duct temperature TD, is calculated in order to set the temperature TSc as the internal chamber temperature set value TSs (S2). The calculation of the duct temperature index value TDs is performed with reference to the data X, Y, Z stored in the data storage unit 103 . A duct temperature upper limit value TDh that is a predetermined value higher than the duct temperature index value TDs, a duct temperature lower limit value TDl that is lower than the duct temperature index value TDs by a predetermined value, and a duct temperature intermediate value that is lower than the duct temperature index value TDs and higher than the duct temperature lower limit value TDl. A value TDc is determined (S3). As shown in FIG. 7, which will be described later, the temperature range between the duct temperature upper limit TDh and the duct temperature lower limit TDl is the control temperature range for the duct temperature TD. These values can be determined automatically from the duct temperature index value TDs, for example. Specifically, the duct temperature upper limit value TDh is 1.0 K higher than the duct temperature index value TDs (TDh=TDs+1.0 K), and the duct temperature lower limit value TDl is 1.0 K lower than the duct temperature index value TDs ( TDl=TDs-1.0K), the duct temperature intermediate value TDc can be 0.5K lower than the duct temperature index value TDs (TDc=TDs-0.5K). Subsequently, based on these values, temperature control is executed in accordance with the change over time (duct cooling characteristic PD) of the duct temperature target value TDt, which is the target for setting the duct temperature TD to the duct temperature index value TDs. (S10). The temperature control in S10 is repeated until the constant temperature and high humidity chamber 1 is powered off and the operation is completed (end).

Specifically, the temperature control in S10 is performed, for example, as follows.
As shown in FIG. 6, while the constant temperature and high humidity chamber 1 is powered on, the duct temperature measurement value TDm is input to the control unit 100 every predetermined sampling time t regardless of the driving state of the compressor 24. (S11). The duct temperature measurement value TDm is compared with the duct temperature upper limit value TDh determined in S3 (S12), and if greater than this (TDm>TDh), the compressor 24 is started (S13). When the duct temperature measurement value TDm is input while the compressor 24 is being driven (S14), the duct temperature measurement value TDm is compared with the duct temperature lower limit value TDl determined in S3 (S15). is smaller (TDm<TDl), the compressor 24 is stopped (S16). On the other hand, when the measured duct temperature value TDm is equal to or higher than the lower limit value TDl of the duct temperature (TDm≧TDl), the calculation unit 104 calculates the measured duct temperature value decrease rate RDm (S17). The calculated duct temperature measurement value drop rate RDm is compared with the duct temperature drop rate target value RDt of the duct cooling characteristic PD (S18). Based on the result of this comparison, the rotation speed CR of the inverter compressor 24 is controlled to increase or decrease, thereby adjusting the cooling capacity, bringing the duct temperature TD closer to the duct temperature index value TDs, and bringing the internal central temperature TSc to approximately the internal temperature. The temperature set value TSs is maintained. Specifically, when the measured duct temperature drop rate RDm has not reached the duct temperature drop rate target value RDt (RDm<RDt), the rotational speed CR of the compressor 24 is controlled to increase (S19). When the duct temperature measured value drop rate RDm is equal to the duct temperature drop rate target value RDt (RDm=RDt), the rotational speed CR of the compressor 24 is maintained (S20). When the duct temperature measured value drop rate RDm is larger than the duct temperature drop rate target value RDt (RDm>RDt), the rotational speed CR of the compressor 24 is controlled to decrease (S21). The above steps are repeated until the command to stop the operation of the constant temperature and high humidity chamber 1 is confirmed (S22), and the duct temperature TD is controlled so as to follow the duct cooling characteristic PD.

In S19 and S21 described above, the target rotation speed CRt of the compressor 24 for changing the duct temperature drop rate RD along the duct cooling characteristic PD is calculated in the calculation unit 104. FIG. In this embodiment, the target rotation speed CRt is set to a rotation speed suitable for realizing the duct temperature drop rate target value RDt defined in the reference table as the duct cooling characteristic PD. The calculated target rotation speed CRt is transmitted as a control signal from the control unit 100 to the compressor 24 via the inverter circuit 105, and the rotation speed CR is appropriately changed.

As an example, the duct cooling characteristic PD can be as shown in FIG.
In the temperature control example shown in FIG. 7, the duct cooling characteristic PD is a combination of linear functions. Note that when a straight line of a linear function is stored and selected as the time-dependent variation of the duct temperature target value TDt (duct cooling characteristic PD), the target duct temperature drop rate target value RDt for the duct temperature TD is Within the temperature range, it is a constant value regardless of the duct temperature measurement value TDm.

When the duct temperature measurement value TDm is in a region (pull-down region) higher than the duct temperature upper limit value TDh (TDm>TDh), the duct temperature drop rate target value RDt drives the compressor 24 at the maximum rotation speed CR _max . The duct temperature drop rate RD _max (constant value) that can be achieved when Further, when the duct temperature measurement value TDm is in a region (supercooling region) lower than the duct temperature lower limit value TDl (TDm<TDl), the duct temperature drop rate target value RDt is The temperature drop rate is RD ₀ (constant value). In the constant temperature and high humidity chamber 1 according to this embodiment, the duct temperature drop rate _RD0 is assumed to be a negative value (when the compressor 24 is stopped, the duct temperature TD rises).

When the measured duct temperature value TDm is within the region (controlled temperature region) equal to or lower than the duct temperature upper limit value TDh and equal to or higher than the duct temperature lower limit value TDl (TDh≧TDm≧TDl), the duct temperature drop rate target value RDt is divided into two stages. shall be subject to change. That is, of the control temperature regions, in the first control temperature region below the duct temperature upper limit value TDh and above the duct temperature intermediate value TDc (TDh≧TDm≧TDc), the duct temperature drop rate target value RDt is set to the value in the pull-down region. It is assumed to be the following positive constant value. Further, in the second control temperature region lower than the duct temperature intermediate value TDc and equal to or higher than the duct temperature lower limit value TDl (TDc>TDm≧TDl), the duct temperature drop rate target value RDt is set to a negative value equal to or higher than the value in the supercooling temperature region. A constant value. In this way, when the duct temperature measurement value TDm is lower than the duct temperature intermediate value TDc, the rotation speed CR of the compressor 24 is actively reduced, and the continuous operation time of the compressor 24 is lengthened. can be done. In FIG. 7, the rotation speed CR of the compressor 24 is set to the maximum rotation speed CRmax in the pull-down region, and is decreased stepwise after reaching the first control temperature region, so that the duct temperature measurement value drop rate RDm is The duct temperature drop rate target value RDt in this temperature range is followed. When the temperature further drops and reaches the second control temperature region, the compressor rotation speed CR is lowered to the minimum rotation speed CR _min , and the duct temperature measurement value drop rate RDm is set to the duct temperature drop rate target value in this temperature range. The duct temperature measurement value TDm is controlled to follow the RDt and become a negative value, that is, to increase very little by little. After that, when the duct temperature measurement value TDm rises and reaches the first control temperature region equal to or higher than the duct temperature intermediate value TDc, the duct temperature drop rate target value RDt becomes a positive value. Control is performed so that CR is increased and the duct temperature measurement value TDm is lowered.

Furthermore, in the present embodiment, the internal temperature sensor 81S also measures the internal temperature TS during operation of the constant temperature and high humidity chamber 1 regardless of the driving state of the compressor 24, and monitors whether temperature control is properly performed. do. Monitoring is preferably performed based on the average internal temperature measurement value TSm for a certain period of time. In this way, it is possible to determine whether the temperature control is appropriate or not without being confused by temporary changes in the internal cold storage temperature TS. At this time, for example, based on the data X, Y, and Z, the temporal change manner of the internal temperature target value TSt (internal cooling characteristic PS) and comparing this internal cooling characteristic PS with the actually measured internal temperature measurement value TSm. Alternatively, conversely, the duct cooling characteristic PD is created from the internal cooling characteristic PS stored in the data storage unit 103, and is stored. The transition of the internal cold storage temperature TS may be monitored based on the cooling characteristic PS. If it is determined that the temperature control is being performed appropriately, the control is continued as it is, and if it is determined that it is not appropriate, the control is performed by correcting the duct cooling characteristic PD as needed. The correction of the control by monitoring the internal chamber temperature TS is not represented in the figure).

[Effects of this embodiment]
As described above, the constant temperature and high humidity chamber 1 according to this embodiment has the following configuration (1).
(1) A heat insulating box (insulating box body) 10 having heat insulating walls and a cooling duct 40D serving as a cold air passage are formed between the heat insulating box 10 and disposed inside the heat insulating box 10 so that the inside is a storage chamber. The inner box 30 designated as 30S, the condenser 22, the cooler 27, and the variable rotation speed compressor 24 are circulatingly connected by refrigerant pipes containing refrigerant to supply cold air into the cooling duct 40D. A cool air supply device 21 for indirectly cooling the inside of the storage chamber 30S, a duct temperature sensor 81D for measuring the duct temperature TD in the cooling duct 40D at every predetermined sampling time t regardless of the driving state of the compressor 24, and a storage chamber 30S. A duct cooling characteristic (cooling characteristic) that indicates a change over time of a duct temperature target value TDt, which is a target for the duct temperature TD for making the internal temperature TS in the chamber 30S equal to the preset internal temperature set value TSs. A data storage unit (storage means) 103 storing PD, and a compressor 24 for decreasing the duct temperature TD following the duct cooling characteristic PD based on the duct temperature measurement value TDm measured by the duct temperature sensor 81D. and an inverter circuit (compressor driving means) 105 that changes the rotation speed CR of the compressor 24 in accordance with the target rotation speed CRt.

According to the configuration of the present embodiment described in (1) above, the variable rotation speed compressor 24 is applied to the constant temperature and high humidity warehouse 1 of the indirect cooling method, and inverter control is performed to turn on the constant speed compressor. The cooling capacity can be finely adjusted compared to the constant temperature and high humidity storage that controls the temperature by /OFF control. Here, in the constant temperature and high humidity warehouse 1 of the indirect cooling system, the cold air from the cold air supply device 21 is not directly supplied into the storage chamber 30S, but the cold air in the cooling duct 40D cools the wall surface of the inner box 30. Thus, the inside temperature TS is indirectly lowered. That is, when the rotation speed CR of the compressor 24 is changed, it is not the inside temperature TS but the duct temperature TD that is directly affected and fluctuates first. Therefore, instead of controlling the compressor based on the temperature inside the chamber as in the conventional direct cooling type constant temperature chamber equipped with an inverter compressor, the configuration of (1) above controls the compressor 24 based on the duct temperature TD. By changing the rotation speed CR, the duct temperature TD can be controlled with high precision, the target internal temperature TS can be achieved while following the duct cooling characteristic PD, and the temperature change can be suppressed. Further, the duct temperature sensor 81D measures the duct temperature TD every predetermined sampling time t, including while the compressor 24 is stopped. The timing at which the compressor 24 should be restarted after being temporarily stopped can be detected as early as possible. As a result, temperature fluctuations in the storage chamber 30S in the constant temperature and high humidity chamber 1 can be effectively suppressed.

Further, the constant temperature and high humidity chamber 1 according to this embodiment has the following configuration (2).
(2) In the above (1), the data storage unit 103 stores temperature-related data X representing the relationship between the inside temperature TS and the duct temperature TD. Based on this, the duct temperature index value TDs is calculated from the internal chamber temperature set value TSs.

In (2) above, the temperature-related data X can be calculated from past actual measurements, etc., in consideration of the size (capacity), arrangement, structure, performance, and the like of related equipment. Based on such temperature-related data X, a duct temperature index value TDs required to realize the internal chamber temperature set value TSs is calculated, and a duct temperature target value is calculated from the duct temperature index value TDs and the duct temperature measurement value TDm. By determining TDt, it is possible to appropriately determine the duct temperature target value TDt for realizing the internal cold storage temperature set value TSs.

Further, the constant temperature and high humidity chamber 1 according to this embodiment has the following configuration (3).
(3) In (1) or (2) above, the duct cooling characteristic PD is stored as a reference table in which the duct temperature drop rate target value RDt, which is the target for the duct temperature drop rate RD, is defined according to the duct temperature TD. Based on the duct temperature measurement value TDm, the calculation unit 104 calculates the target rotation speed CR for achieving the duct temperature drop rate target value RDt.

According to the above configuration (3), by storing the duct cooling characteristic PD as a reference table defined in advance, the calculation of the target rotation speed CRt of the compressor 24 according to the duct temperature measurement value TDm can be performed more easily. It can be done easily and quickly.

Further, the constant temperature and high humidity chamber 1 according to this embodiment has the following configuration (4).
(4) In (3) above, the calculation unit 104 calculates a duct temperature index value TDs, which is an index of the duct temperature TD for making the inside temperature TS the preset inside temperature set value TSs, The inverter circuit 105 starts the compressor 24 when the duct temperature measurement value TDm becomes higher than the duct temperature upper limit value TDh (for example, +1.0 K) which is higher than the duct temperature index value TDs by a predetermined value (for example, +1.0 K). However, when it becomes lower than the duct temperature lower limit value TDl, which is lower than the duct temperature index value TDs by a predetermined value (eg, -1.0K), the compressor 24 is stopped. Further, the duct temperature drop rate target value RDt is lower than the duct temperature index value TDs (for example, −0.5 K), higher than the duct temperature lower limit value TDl, higher than the duct temperature intermediate value TDc, and lower than the duct temperature upper limit value TDh. It takes a positive value in the first control temperature region, and takes a negative value in the second control temperature region below the duct temperature intermediate value TDc and above the duct temperature lower limit value TDl.

According to the configuration (4) above, when the duct temperature measurement value TDm drops to the control temperature region and reaches the second control temperature region, the inverter circuit 105 actively reduces the rotational speed CR of the compressor 24. and the cooling capacity is reduced. As a result, the duct temperature measurement value TDm is less likely to drop to the duct temperature lower limit value TDl, and the compressor 24 is continuously operated over a longer period of time. As a result, the increase in the inside temperature TS due to the stoppage of the compressor 24 is reduced, and the temperature fluctuation in the storage room 30S is suppressed.

Further, the constant temperature and high humidity chamber 1 according to this embodiment has the following configuration (5).
(5) In any one of (1) to (4) above, an internal temperature sensor 81S provided in the storage chamber 30S for measuring the internal temperature TS, and an internal temperature sensor 81S provided outside the insulation box 10 for measuring the ambient temperature TA The data storage unit 103 stores the duct temperature measurement value TDm, the internal temperature measurement value TSm measured by the internal temperature sensor 81S, and the ambient temperature sensor 81A measured by the ambient temperature sensor 81A. Central temperature estimation data Y for estimating the internal central temperature TSc in the central portion of the storage chamber 30S from the measured ambient temperature TAm is further stored. From the internal temperature measurement value TSm and the ambient temperature measurement value TAm, the internal central temperature TSc is estimated based on the central temperature estimation data Y, and the internal internal temperature TSc is calculated as a preset internal temperature set value TSs. A target duct temperature index value TDs for the duct temperature TD is calculated.

According to the above configuration (5), from the internal temperature sensor 81S installed at a specific location (in this embodiment, the upper part of the storage chamber 30S), the internal temperature sensor 81S detects the internal temperature at the central portion of the storage chamber 30S. The temperature TSc is estimated, and the inside central temperature TSc is controlled to be the inside temperature set value TSs. Therefore, it is possible to maintain the entire storage chamber 30S near the internal temperature set value TSs, taking into account variations in temperature (internal temperature TS) in the storage chamber 30S.

Further, the constant temperature and high humidity chamber 1 according to this embodiment has the following configuration (6).
(6) In the above (5), a dew condensation prevention heater (an example of ancillary equipment) 70 that affects the inside temperature TS according to the energization state is further provided, and the data storage unit 103 stores the energization state of the dew condensation prevention heater 70. Supplementary data Z about the influence of the temperature on the inside central temperature TSc is further stored. Based on data Y for estimating central temperature and supplementary data Z, the internal central temperature TSc is inferred from the information about the energization state of .

According to the above configuration (6), the dew condensation prevention heater 70 is attached near the opening of the heat insulation door 18 and the heat insulation box 10, and the constant temperature and high humidity chamber 1 in which the internal temperature TS fluctuates depending on the energization state of these is higher. It is possible to maintain the entire storage chamber 30S around the internal temperature set value TSs with accuracy.

Moreover, the operating method of the constant temperature and high humidity chamber 1 according to the present embodiment has the following configuration (7).
(7) Insulation box 10 having an insulation wall and cooling duct 40D serving as a cold air passage is formed between insulation box 10, and the interior is disposed inside insulation box 10 to form storage chamber 30S inside. The box 30, the condenser 22, the cooler 27, and the variable rotation speed compressor 24 are circulatingly connected by refrigerant pipes containing refrigerant, and supply cold air to the cooling duct 40D to indirectly move the inside of the storage chamber 30S. and a duct temperature target for the duct temperature TD in the cooling duct 40D for setting the internal temperature TS in the storage chamber 30S to the preset internal temperature set value TSs. and a data storage unit 103 in which the duct cooling characteristic PD indicating the change over time of the value TDt is stored. Measure the duct temperature TD in the cooling duct 40D every t, calculate the target rotation speed CRt of the compressor 24 for decreasing the duct temperature TD in accordance with the duct cooling characteristic PD based on the duct temperature measurement value TDm, The rotation speed CR of the compressor 24 is changed according to the target rotation speed CRt.

According to the above configuration (7), the constant temperature and high humidity warehouse 1 can be operated while effectively suppressing fluctuations in the internal temperature TS in the storage chamber 30S.

<Other embodiments>
The technology disclosed in this specification is not limited to the embodiments described in the above description and drawings, and includes the following embodiments, for example.

(1) In the above embodiment, an example in which the duct cooling characteristic PD is represented by a combination of linear functions has been described, but the present invention is not limited to this. The duct cooling characteristic PD may be expressed as a function of second order or higher.

(2) In the above embodiment, the user sets and inputs only the internal chamber temperature setting value TSs to the target temperature setting unit 91, and based on the duct temperature index value TDs calculated from the internal chamber temperature setting value TSs, the duct temperature upper limit Although the case where the value TDh, the duct temperature lower limit value TDl, and the duct temperature intermediate value TDc are determined has been described, the present invention is not limited to this. For example, according to the purpose of use (food to be stored, etc.) and the installation environment of the constant temperature and high humidity chamber 1, the user can set and input the upper limit value of the chamber temperature, the lower limit value of the chamber temperature, and the intermediate value of the chamber temperature. may From these input values, the duct temperature upper limit value TDh, the duct temperature lower limit value TDl, and the duct temperature intermediate value TDc can be calculated while referring to the data X, Y, Z, and the like.

(3) Although the control of the condenser fan 23 and the duct fan 29 was not particularly mentioned in the above embodiment, their rotation speeds may be controlled in conjunction with the rotation speed CR of the compressor 24 . For example, the rotation speed of the condenser fan 23 is preferably increased as the amount of refrigerant supplied from the cool air supply device 21 increases so that the temperature of the condenser 22 does not become high. Therefore, the rotation speed of the condenser fan 23 may be increased or decreased in the same manner as the rotation speed CR of the compressor 24, for example. Also, by changing the number of rotations of the duct fan 29, the cooling capacity can be adjusted by changing the circulation amount of cool air. Therefore, the rotation speed of the duct fan 29 may be changed in a manner different from that of the rotation speed CR of the compressor 24, and the control may be performed by combining them.

(4) The constant temperature and high humidity chamber is not limited to those described in the above embodiments, and may be configured to cool a plurality of independent storage chambers, or may include a plurality of compressors. good. The specific temperature range of the internal temperature TS of the storage compartment is not particularly limited, and this technology can also be applied to a constant temperature and high humidity storage equipped with storage compartments used for either refrigeration or freezing. is.

DESCRIPTION OF SYMBOLS 1... Constant temperature and high humidity chamber, 10... Insulation box (insulation box body), 21... Cold air supply device, 22... Condenser, 23... Condenser fan, 24... Compressor, 25... Electrical box (control box), 27... Cooler 29 Duct fan (cooling fan) 30 Inner box 30S Storage room 40D Cooling duct 70 Condensation prevention heater (an example of ancillary equipment) 71 Condensation prevention heater electrification detection sensor (incidental equipment Example of state detection sensor), 81A... Ambient temperature sensor, 81D... Duct temperature sensor, 81S... Inside temperature sensor, 91... Target temperature setting unit, 100... Control unit, 102... Time measuring unit, 103... Data storage unit (storage Means), 104: computing unit (computing means), 105: inverter circuit (compressor drive means), TD: duct temperature, TDc: duct temperature intermediate value, TDh: duct temperature upper limit value, TDl: duct temperature lower limit value, TDm Measured value of duct temperature, TDs: Index value of duct temperature, TDt: Target value of duct temperature, TS: Inside temperature, TSc: Inside temperature in the middle, TSm: Inside temperature measured value, TSs: Inside temperature set value, TSt TA: ambient temperature TAm: measured ambient temperature PD: duct cooling characteristics (cooling characteristics) RD: duct temperature drop rate RDm: duct temperature drop rate RDt: duct temperature drop Rate target value, X... Temperature-related data, Y... Central temperature estimation data, Z... Supplementary data

Claims (4)

a heat insulating box body having heat insulating walls;
an inner box arranged inside the heat insulating box while forming a cooling duct serving as a cold air passage between the heat insulating box and having an interior serving as a storage room;
A cold air supply device in which a condenser, a cooler, and a variable rotation speed compressor are cyclically connected by a refrigerant pipe containing a refrigerant, and indirectly cools the inside of the storage chamber by supplying cold air into the cooling duct. When,
a duct temperature sensor that measures the duct temperature in the cooling duct at predetermined sampling times regardless of the operating state of the compressor;
storage means for storing a cooling characteristic indicative of a change over time of a duct temperature target value, which is a target for the duct temperature for setting the internal temperature in the storage chamber to a preset internal temperature set value;
calculating means for calculating a target rotation speed of the compressor for decreasing the duct temperature according to the cooling characteristic, based on the duct temperature measured value measured by the duct temperature sensor;
A constant temperature and high humidity storage comprising a compressor driving means for changing the rotation speed of the compressor in accordance with a target rotation speed ,
The cooling characteristic includes a target duct temperature drop rate target value for the duct temperature drop rate defined according to the duct temperature;
The computing means is
the target rotation speed for achieving the duct temperature drop rate target value based on the measured duct temperature;
calculating a duct temperature index value that is an index of the duct temperature for setting the internal temperature to a preset internal temperature set value;
The compressor driving means is
activating the compressor when the measured duct temperature exceeds a duct temperature upper limit value that is higher than the duct temperature index value by a predetermined value;
stopping the compressor when the duct temperature measurement value falls below a duct temperature lower limit value lower than the duct temperature index value by a predetermined value;
The duct temperature drop rate target value is
A positive value in a first control temperature region equal to or higher than the duct temperature intermediate value lower than the duct temperature index value and higher than the duct temperature lower limit value and equal to or lower than the duct temperature upper limit value,
A constant-temperature and high-humidity chamber having a negative value equal to or greater than the duct temperature drop rate when the compressor is stopped in a second control temperature region that is less than the intermediate duct temperature value and equal to or greater than the lower limit value of the duct temperature . The storage means stores temperature-related data representing a relationship between the internal temperature and the duct temperature,
2. The constant temperature and high humidity chamber according to claim 1, wherein said calculation means calculates said duct temperature target value from said chamber interior temperature set value based on said temperature related data. an internal temperature sensor provided in the storage chamber for measuring the internal temperature;
An ambient temperature sensor that is provided outside the heat insulating box and measures the ambient temperature,
In the storage means, from the measured duct temperature, the measured internal temperature measured by the internal temperature sensor, and the measured ambient temperature measured by the ambient temperature sensor, Central temperature estimation data for estimating the inner center temperature is further stored,
The computing means is
estimating the central temperature in the refrigerator based on the data for estimating the central temperature from the measured duct temperature, the measured interior temperature, and the measured ambient temperature;
3. The constant temperature and high humidity chamber according to claim 1, wherein a target duct temperature index value for said duct temperature is calculated for setting said chamber central temperature to a preset chamber temperature setting value. Further equipped with incidental equipment that can affect the temperature inside the storage according to the state,
The storage means further stores supplementary data regarding the influence of the state of the supplementary equipment on the internal central temperature,
The calculation means is configured to calculate the duct temperature measured value, the internal temperature measured value, the ambient temperature measured value, and information on the state of the incidental equipment based on the data for estimating the central temperature and the incidental data. 4. The constant temperature and high humidity chamber according to claim 3 , wherein the temperature in the middle of the chamber is estimated.

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