JP2007107730A - Cooling system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling system capable of reducing initial costs in installing the system, and achieving benefits of reduction of running cost and the like by saving energy. <P>SOLUTION: Stop suction pressures PSa-PSc of compressors 5a-5c can be properly set without collecting special operation data from each of refrigerating freezing devices 1-4, as an in-store enthalpy E is determined on the basis of an in-store temperature TI and an in-store humidity UI, and the stop suction pressure PSa-PSc of the compressors 5a-5c according to the enthalpy E are set. Further as each of the compressors 5a-5c is switched on and off to be driven on the basis of the stop suction pressure PSa-PSc of the compressors 5a-5c according to the in-store enthalpy E, the capacity is properly variable in stages by selectively operating the plurality of compressors 5a-5c. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention includes a plurality of refrigeration refrigerators that perform cooling by controlling refrigerant intake into an evaporator, and a multi refrigerator that performs variable capacity in stages by selectively operating a plurality of compressors connected in parallel. It is related with the provided cooling system.

  In a relatively large store such as a supermarket, a cooling system using a common refrigerator called a multi refrigerator is generally used. This cooling system includes a plurality of refrigeration equipment comprising an open type refrigerated showcase, a door-mounted freezer, etc., a multi-freezer having a plurality of compressors, and a main controller for managing the operation of each refrigeration equipment and multi-freezer And.

  Each refrigeration equipment has an evaporator, a solenoid valve for taking refrigerant into the evaporator, and a temperature sensor for detecting the temperature in the actual cabinet, and the solenoid valve so that the actual chamber temperature becomes the set chamber temperature. Cooling is performed by controlling the refrigerant intake by opening and closing the. The multi-refrigerator has a plurality of compressors connected in parallel and a plurality of compressor stop pressure switches provided on the suction side of each compressor, and each compressor is turned on and off based on signals from pressure switches having different operating pressure values. By driving, the capacity is gradually changed by selectively operating a plurality of compressors.

Recently, multi-refrigerators that vary their capacities by controlling the rotation speed of each compressor have been put into practical use. Since this multi-refrigerator can change the capacity linearly, it can contribute to energy saving as compared with a multi-refrigerator of the type that changes the capacity in stages.
Japanese Patent No. 3666174

  A cooling system using a multi-chiller of a type that performs variable capacity linearly can obtain benefits such as a reduction in running costs due to energy saving, but a refrigeration system using a multi-freezer of a type that performs variable capacity in stages. Compared to the initial cost for system installation.

  In other words, it is possible to reduce the initial cost related to system installation by making it possible to perform a variable capacity that is similar to that of a multi-chiller that linearly varies the capacity even in a multi-chiller that performs variable capacity in stages. Benefits such as reduced running costs due to energy savings can also be obtained.

  The present invention was created in view of the above circumstances, and the object of the present invention is to provide a cooling system that can suppress initial costs related to system installation and can also obtain benefits such as reduction of running costs due to energy saving. There is to do.

  In order to achieve the above-mentioned object, the present invention gradually changes the capacity by selectively operating a plurality of refrigeration equipment that performs cooling by controlling refrigerant intake into the evaporator and a plurality of compressors connected in parallel. A cooling system comprising a multi-refrigerator for performing an in-store enthalpy based on the in-store temperature and in-store humidity and setting a stop suction pressure for each compressor in accordance with the in-store enthalpy, and a set compression And a means for driving the plurality of compressors on and off based on the stop suction pressure for each machine.

  According to this cooling system, the store enthalpy is obtained based on the store temperature and the store humidity, and the stop suction pressure for each compressor is set according to the store enthalpy, so special operation data is collected from each refrigeration unit. Without stopping, the stop suction pressure for each compressor can be set appropriately. In addition, since each compressor is driven on and off based on the stop suction pressure for each compressor corresponding to the in-store enthalpy, it is possible to accurately perform stepwise capacity variation by selectively operating a plurality of compressors. In other words, even though it is a type of multi-chiller that changes capacity in stages, it can perform variable capacity similar to that of a type of multi-chiller that changes capacity linearly, thus reducing the initial cost of system installation. In addition, it is possible to obtain benefits such as reduced running costs due to energy saving.

  The present invention also provides a plurality of refrigeration refrigerators that perform cooling by controlling refrigerant intake into the evaporator, and a multi refrigerator that performs variable capacity in stages by selectively operating a plurality of parallel-connected compressors. A means for setting a stop suction pressure for each compressor according to the date and time, a means for driving on and off a plurality of compressors based on the set stop suction pressure for each compressor, and It is characterized by comprising.

  According to this cooling system, since the stop suction pressure for each compressor is set according to the date and time, the stop suction pressure for each compressor is appropriately set without collecting special operation data from each refrigeration equipment. Can be set. In addition, since each compressor is driven on and off based on the stop suction pressure for each compressor according to the date and time, it is possible to accurately perform stepwise capacity variation by selectively operating a plurality of compressors. In other words, even though it is a type of multi-chiller that changes capacity in stages, it can perform variable capacity similar to that of a type of multi-chiller that changes capacity linearly, thus reducing the initial cost of system installation. In addition, it is possible to obtain benefits such as reduced running costs due to energy saving.

  ADVANTAGE OF THE INVENTION According to this invention, the cooling system which can suppress the initial cost concerning system installation and can also obtain benefits, such as a running cost reduction by energy saving, can be provided.

  The above object and other objects, structural features, and operational effects of the present invention will become apparent from the following description and the accompanying drawings.

  1 to 4 show an embodiment of the present invention. FIG. 1 is an overall configuration diagram of a cooling system, FIG. 2 is a diagram showing a processing flow relating to setting of a stop suction pressure for each compressor, and FIG. 3 is a data table used when setting a stop suction pressure for each compressor. FIG. 4 is a diagram showing a processing flow relating to the selective operation of the compressor.

  First, the entire configuration of the cooling system will be described with reference to FIG. In FIG. 1, 1 to 4 are refrigerated refrigerators, 5 is a multi refrigerator, 6 is a main controller, RP1 is a refrigerant forward pipe, RP2 is a refrigerant return pipe, and SL1 and SL2 are signal lines.

  Each of the refrigerated refrigerators 1 to 4 includes an open-type refrigerated showcase, a freezer with a door, and the like, and is installed at a predetermined position in the store. Each refrigeration equipment 1 to 4 includes an evaporator 1a to 4a, an expansion valve 1b to 4b provided on the inlet side of the evaporator 1a to 4a, and an electromagnetic valve 1c provided on the inlet side of the expansion valve 1b to 4b. -4c, internal fans 1d-4d for circulating cooling air, internal temperature sensors 1e-4e for detecting actual internal temperatures (blowing temperatures) TA1-TA4, controllers 1f-4f, At least the internal temperature setting devices 1g to 4g for determining the internal temperature TS1 to TS4 are provided. Incidentally, the configuration of the solenoid valves (1c to 4c) and the expansion valves (1b to 4b) for controlling the refrigerant intake into the evaporators (1a to 4a) can be replaced by an electronic expansion valve having both functions. . The evaporators 1a to 4a of the refrigeration refrigerators 1 to 4 are connected in parallel to the refrigerant outlet and the refrigerant inlet of the multi-chiller 5 via the refrigerant forward pipe RP1 and the refrigerant return pipe RP2.

  Each controller 1f-4f has a control part of a microcomputer composition, a drive part, a communication part, and a detection part, and each communication part is connected to main controller 6 via signal line SL1, and each detection part is in a warehouse. Temperature sensors 1e to 4e are connected. Each driving unit performs opening / closing driving of the electromagnetic valves 1c to 4c and on / off driving of the internal fans 1d to 1d based on a signal from the control unit. The memory of each controller is cooled by controlling the refrigerant intake by opening and closing the solenoid valves (1c to 4c) so that the actual internal temperature (TA1 to TA4) becomes the set internal temperature (TS1 to TS4). And a communication program for transmitting the set internal temperature (TS1 to TS4), the actual internal temperature (TA1 to TA4), and the like to the main controller 6 are stored.

  The multi refrigerator 5 includes a plurality (three in the figure) of compressors 5a to 5c connected in parallel, a condenser 5d provided on the discharge side of the compressors 5a to 5c, and a suction side of the compressors 5a to 5c. At least a pressure sensor 5e for detecting an actual suction pressure (PA) and a controller 5f. Incidentally, each compressor 5a-5c may have the same capability, or may have different capabilities. The base end of the refrigerant forward pipe RP1 is connected to the refrigerant outlet (the outlet side of the condenser 5b) of the multi-refrigerator 5, and the refrigerant return pipe RP2 is terminated to the refrigerant inlet (the suction side of the compressors 5a to 5c). Is connected.

  The controller 5f includes a control unit having a microcomputer configuration, a drive unit, a communication unit, and a detection unit. The communication unit is connected to the main controller 6 via a signal line SL2, and a pressure sensor 5e is connected to the detection unit. Yes. A drive part performs on-off drive of each compressor 5a-5c based on the signal from a control part. The memory of the control unit stores a compressor selection operation program to be described later for selectively operating the plurality of compressors 5a to 5c, a communication program for transmitting the actual suction pressure PA and the like to the main controller 6, and the like. Has been.

  The main controller 6 detects a microcomputer configuration control unit 6a, a setting unit 6b including input keys and a display, a detection unit 6c, an in-store temperature sensor 6d for detecting the in-store temperature TI, and an in-store humidity UI. Store humidity sensor 6e, a communication unit 6f, and a connector 6g connected to the communication unit 6f.

  The in-store temperature sensor 6d and the in-store humidity sensor 6e are installed at in-store positions that are not easily affected by heat from the respective refrigeration units 1 to 4 and the in-store air conditioner, and are connected to the detection unit 6c. Further, the ends of the signal lines SL1 and SL2 are connected to the connector 6g. Further, in the memory of the control unit 6a, a stop suction pressure setting program to be described later for setting stop suction pressures PSa to PSc for the compressors 5a to 5c, various data tables to be described later, and a stop suction pressure after setting. A communication program and the like for transmitting PSa to PSc to the multi-chiller 5 are stored.

  Next, with reference to FIG. 2 and FIG. 3, a processing flow relating to setting of the stop suction pressure for each compressor executed by the main controller 6 will be described.

  After the system is started, the in-store enthalpy E is obtained based on the current in-store temperature TI and in-store humidity UI detected by the in-store temperature sensor 6d and the in-store humidity sensor 6e (step S11 in FIG. 2). Here, using a data table (not shown) having the in-store temperature TI and the in-store humidity UI as parameters, the in-store enthalpy E is selected from the corresponding in-store temperature TI and in-store humidity UI. Of course, the in-store enthalpy E can be obtained by a calculation formula using the in-store temperature TI and the in-store humidity UI as variables without using a data table.

  After obtaining the in-store enthalpy E, stop suction pressures PSa to PSc for the compressors 5a to 5c corresponding to the in-store enthalpy E are set (step S12 in FIG. 2). Here, the stop suction pressure PSa to PSc for each of the compressors 5a to 5c is selected from the corresponding in-store enthalpy E using the data table of FIG. For example, when the in-store enthalpy E corresponds to E5, the stop suction pressure PSa of the compressor 5a is 0.36 MPa, the stop suction pressure PSb of the compressor 5b is 0.44 MPa, and the stop suction pressure PSc of the compressor 5c is 0.51 MPa. Is selected. Of course, the stop suction pressure PSa to PSc for each of the compressors 5a to 5c can be obtained by a calculation formula using the in-store enthalpy E as a variable without using the data table.

  After setting the stop suction pressures PSa to PSc for each of the compressors 5a to 5c corresponding to the in-store enthalpy E, the set stop suction pressures PSa to PSc for each of the compressors 5a to 5c are transmitted to the controller 5f of the multi-chiller 5. (Step S13 in FIG. 2).

  Next, with reference to FIG. 4, a processing flow related to the selective operation of the compressor executed by the controller 5f of the multi-chiller 5 will be described.

  The controller 5f of the multi-chiller 5 waits for transmission of the stop suction pressure PSa to PSc for each of the compressors 5a to 5c from the main controller 6, and when there is a transmission, the stop suction pressure PSa to PSc for each of the compressors 5a to 5c. Is stored in the memory of the control unit (steps S21 and S22 in FIG. 4).

  Then, the compressors 5a to 5c are turned on and off based on the stop suction pressures PSa to PSc for each of the compressors 5a to 5c, thereby performing stepwise capacity variation by selectively operating the plurality of compressors 5a to 5c ( Step S23 in FIG.

  For example, when the in-store enthalpy E corresponds to E5 in FIG. 3 and 0.36 MPa, 0.44 MPa, and 0.51 MPa are transmitted as the stop suction pressures PSa to PSc for the compressors 5a to 5c, the actual suction pressure is transmitted. When PA is larger than 0.51 MPa, all the compressors 5a to 5c are operated, and when the actual suction pressure PA is in the range of 0.51 MPa ≧ PA> 0.44 MPa, the compressors 5a and 5b are operated. When the actual suction pressure PA is in the range of 0.44 MPa ≧ PA> 0.36 MPa, the compressor 5a is operated, and when the actual suction pressure PA is 0.36 MPa or less, all the compressors 5a to 5c are stopped. Thus, the plurality of compressors 5a to 5c are selectively operated to change the capacity in stages.

  When the plurality of compressors 5a to 5c are driven on and off based on the set stop suction pressures PSa to PSc for the compressors 5a to 5c, new stop suction pressures PSa to PSc are transmitted from the main controller 6. In the same manner as described above, the transmitted new stop suction pressures PSa to PSc are stored in the memory of the control unit, and the compressors 5a to 5c are driven on and off based on the stop suction pressures PSa to PSc. Stepwise capacity variation is performed by selectively operating the plurality of compressors 5a to 5c (step S24 in FIG. 4).

  According to the above-described cooling system, since the store enthalpy E is obtained based on the store temperature TI and the store humidity UI, the stop suction pressures PSa to PSc for the compressors 5a to 5c corresponding to the store enthalpy E are set. The stop suction pressures PSa to PSc for each of the compressors 5a to 5c can be appropriately set without collecting special operation data from each of the refrigeration refrigerators 1 to 4. Moreover, since the compressors 5a to 5c are driven on and off based on the stop suction pressures PSa to PSc for the compressors 5a to 5c corresponding to the in-store enthalpy E, the plurality of compressors 5a to 5c are selectively operated. Step-by-step variable capability can be performed accurately.

  In other words, although it is a type of multi-chiller 5 that performs variable capacity in stages, it can perform variable capacity that is similar to that of a multi-cooler that linearly varies capacity, thus reducing the initial cost for system installation. In addition to being able to suppress, benefits such as reduction in running cost due to energy saving can be obtained.

  Moreover, in the existing situation where many cooling systems using a multi-chiller of the type in which the capacity is changed in stages are still installed and used, the same control as the cooling system can be performed on the cooling system. Similar effects can be obtained simply by making such improvements.

  In other words, the multi-cooler of the type that linearly changes the capacity by partially improving the control system without replacing the existing cooling system using the multi-cooler of the type that changes the capacity stepwise with a new cooling system. Since it is possible to save energy by changing the approximate capacity, there is a great practical advantage.

  5 to 10 show process flows for more appropriately setting the stop suction pressures PSa to PSc for the compressors 5a to 5c in the cooling system, respectively.

  The processing flow shown in FIG. 5 relates to the change of the stop suction pressures PSa to PSc when the capacity is excessive. Here, the number of on / off times of each compressor 5a-5c per predetermined time when each compressor 5a-5c is driven on / off based on the set stop suction pressure PSa-PSc for each compressor 5a-5c is set. When the counted number of on / off times is equal to or greater than a predetermined value, the stop suction pressures PSa to PSc are changed to high stop suction pressures PSa to PSc considering that the capacity is excessive (see steps S31 to S34). . As a method of changing the stop suction pressures PSa to PSc to high stop suction pressures PSa to PSc, the current stop suction pressures PSa to PSc selected in the data table of FIG. Either a method of substituting the stop suction pressures PSa to PSc two steps below or a method of adding predetermined values to the current stop suction pressures PSa to PSc selected in the data table of FIG. 3 can be employed.

  The processing flow of FIG. 6 relates to the change of the stop suction pressures PSa to PSc when the capacity is excessive. Here, based on the set stop suction pressures PSa to PSc for the compressors 5a to 5c, the average value per predetermined time of the actual suction pressure PA when the compressors 5a to 5c are driven on and off is obtained as Apa. When the obtained average value Apa is equal to or less than a predetermined value, it is considered that the capacity is excessive, and the stop suction pressures PSa to PSc are changed to high stop suction pressures PSa to PSc (see steps S41 to S44). As a method of changing the stop suction pressures PSa to PSc to high stop suction pressures PSa to PSc, the current stop suction pressures PSa to PSc selected in the data table of FIG. Either a method of substituting the stop suction pressures PSa to PSc two steps below or a method of adding predetermined values to the current stop suction pressures PSa to PSc selected in the data table of FIG. 3 can be employed.

  The processing flow of FIG. 7 relates to the change of the stop suction pressures PSa to PSc when the capacity is insufficient. Here, the actual internal temperature TA1 of each refrigeration refrigerator 1 to 4 when the compressors 5a to 5c are driven on and off based on the set stop suction pressures PSa to PSc for the compressors 5a to 5c. Recognize the transition of TA4, and when the recognized transition of the internal temperature TA1 to TA4 tends to be higher than the set internal temperature TS1 to TS4, it is assumed that the capacity is insufficient and the stop suction pressures PSa to PSc are low. The stop suction pressures PSa to PSc are changed (see steps S51 to S54). As a method of changing the stop suction pressures PSa to PSc to low stop suction pressures PSa to PSc, the current stop suction pressures PSa to PSc selected in the data table of FIG. Alternatively, any one of the method of substituting the stop suction pressures PSa to PSc at the second stage and the method of subtracting a predetermined value from the current stop suction pressures PSa to PSc selected in the data table of FIG. 3 can be adopted. .

  The processing flow of FIG. 8 relates to the change of the stop suction pressures PSa to PSc when at least one of the refrigeration refrigerators 1 to 4 enters the defrosting operation. Here, based on the set stop suction pressures PSa to PSc for the compressors 5a to 5c, when the compressors 5a to 5c are driven on / off, the refrigeration refrigerators (1 to 4) that have entered the defrosting operation When there is a refrigerated refrigeration equipment (1-4) that has entered defrosting, the number and the set temperature in the refrigerator are grasped, and the number and storage of the refrigerated refrigeration equipment (1-4) that has undergone defrosting. The stop suction pressures PSa to PSc are changed to high stop suction pressures PSa to PSc so as to cancel the excess capacity based on the internal set temperature (see steps S61 to S64). As a method of changing the stop suction pressures PSa to PSc to high stop suction pressures PSa to PSc, the current stop suction pressures PSa to PSc selected in the data table of FIG. Either a method of substituting the stop suction pressures PSa to PSc two steps below or a method of adding predetermined values to the current stop suction pressures PSa to PSc selected in the data table of FIG. 3 can be employed.

  The processing flow of FIG. 9 relates to the change of the stop suction pressures PSa to PSc when at least one of the refrigeration units 1 to 4 returns from the defrosting operation to the normal operation. Here, based on the set stop suction pressures PSa to PSc for the compressors 5a to 5c, when the compressors 5a to 5c are driven on and off, the refrigeration equipment (1 to 4) returned from defrosting. When there is a refrigerated refrigerator (1-4) that has been restored from defrost, the number and the set temperature inside the refrigerator are grasped, and the number and refrigerator of the refrigerated refrigerator (1-4) that has been recovered from defrost. The stop suction pressures PSa to PSc are changed to low stop suction pressures PSa to PSc so that rapid cooling can be performed based on the internal set temperature (see steps S71 to S74). Since the compressors 5a to 5c can be driven on and off based on the low stop suction pressures PSa to PSc after the change, a short time may be set at the same time. The stop suction pressures PSa to PSc before the change may be changed again. As a method of changing the stop suction pressures PSa to PSc to low stop suction pressures PSa to PSc, the current stop suction pressures PSa to PSc selected in the data table of FIG. Alternatively, any one of the method of substituting the stop suction pressures PSa to PSc at the second stage and the method of subtracting a predetermined value from the current stop suction pressures PSa to PSc selected in the data table of FIG. 3 can be adopted. .

  The processing flow of FIG. 10 relates to the change of the stop suction pressures PSa to PSc when the night cover is attached to at least one of the refrigeration refrigerators 1 to 4. Here, the refrigerator-freezer (1-4) with which the night cover was mounted | worn when each compressor 5a-5c was driven on-off based on the stop suction pressure PSa-PSc for every set compressor 5a-5c. When there are refrigerated refrigerators (1-4) equipped with night covers, grasp the number and the set temperature in the refrigerator, and the number of refrigerated refrigerators (1-4) equipped with night covers The stop suction pressures PSa to PSc are changed to high stop suction pressures PSa to PSc so as to cancel out the excess capacity based on the set temperature in the cabinet (see steps S81 to S84). As a method of changing the stop suction pressures PSa to PSc to high stop suction pressures PSa to PSc, the current stop suction pressures PSa to PSc selected in the data table of FIG. Either a method of substituting the stop suction pressures PSa to PSc two steps below or a method of adding predetermined values to the current stop suction pressures PSa to PSc selected in the data table of FIG. 3 can be employed.

  FIG. 11 is an overall configuration diagram of a cooling system showing another embodiment of the present invention. The cooling system shown in the figure is different from the cooling system shown in FIG. 1 except that the detection unit 6c, the in-store temperature sensor 6d, and the in-store humidity sensor 6e are excluded from the main controller 6, and date / time data is used instead of the detection unit 6c. A timer unit 6h for sending to the control unit 6a is provided. In the memory of the control unit 6a of the main controller 6, the date and time is used as a parameter instead of the stop suction pressure selection data table using the in-store enthalpy as a parameter. A data table (not shown) for selecting the stop suction pressure is stored.

  After starting the system, the main controller 6 selects stop suction pressures PSa to PSc for the compressors 5a to 5c according to the date and time based on the date and time data sent from the timer unit 6h, and sends it to the controller 5f of the multi-chiller 5 To transmit. The controller 5f of the multi refrigerator 5 turns on and off the compressors 5a to 5c in the same manner as described above based on the stop suction pressures PSa to PSc for the transmitted compressors 5a to 5c. Step-by-step capacity change by selective operation.

  According to this cooling system, since the stop suction pressures PSa to PSc for each of the compressors 5a to 5c according to the date and time are set, the compression can be performed without collecting special operation data from each refrigeration equipment 1 to 4. The stop suction pressures PSa to PSc for each of the machines 5a to 5c can be set appropriately. Moreover, since the compressors 5a to 5c are driven on and off based on the stop suction pressures PSa to PSc for each of the compressors 5a to 5c according to the date and time, stepwise by selective operation of the plurality of compressors 5a to 5c. Variable ability can be performed accurately.

  In other words, although it is a type of multi-chiller 5 that performs variable capacity in stages, it can perform variable capacity that is similar to that of a multi-cooler that linearly varies capacity, thus reducing the initial cost for system installation. In addition to being able to suppress, benefits such as reduction in running cost due to energy saving can be obtained.

  Moreover, in the existing situation where many cooling systems using a multi-chiller of the type in which the capacity is changed in stages are still installed and used, the same control as the cooling system can be performed on the cooling system. Similar effects can be obtained simply by making such improvements.

  In other words, the multi-cooler of the type that linearly changes the capacity by partially improving the control system without replacing the existing cooling system using the multi-cooler of the type that changes the capacity stepwise with a new cooling system. Since it is possible to save energy by changing the approximate capacity, there is a great practical advantage.

  Incidentally, the processing flow relating to the change of the stop suction pressure described with reference to FIGS. 5 to 10 can also be applied to the cooling system shown in FIG. 11.

  In the above-described embodiment, the three refrigerators 5a to 5c are connected in parallel as the multi-refrigerator 5. However, a multi-refrigerator in which four or more compressors or two compressors are connected in parallel is used instead. Even when used, the present invention can be applied to obtain the same effects as described above.

  In the above-described embodiment, a cooling system including four refrigeration refrigerators 1 to 4 is illustrated, but the present invention is applied to a cooling system having five or more refrigeration refrigerators in the same manner as described above. The effect of this can be obtained.

1 is an overall configuration diagram of a cooling system showing an embodiment of the present invention. It is a figure which shows the processing flow which concerns on the setting of the stop suction pressure for every compressor. It is a figure which shows the data table used when setting the stop suction pressure for every compressor. It is a figure which shows the processing flow which concerns on the selective operation | movement of a compressor. It is a figure which shows the processing flow which concerns on the change of a stop suction pressure. It is a figure which shows the processing flow which concerns on the change of a stop suction pressure. It is a figure which shows the processing flow which concerns on the change of a stop suction pressure. It is a figure which shows the processing flow which concerns on the change of a stop suction pressure. It is a figure which shows the processing flow which concerns on the change of a stop suction pressure. It is a figure which shows the processing flow which concerns on the change of a stop suction pressure. It is a whole block diagram of the cooling system which shows other embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1-4 ... Refrigerated refrigeration equipment, 1a-4a ... Evaporator, 1c-4c ... Solenoid valve, 1f-4f ... Controller, 5 ... Multi refrigerator, 5a-5c ... Compressor, 5e ... Pressure sensor, 5f ... Controller, 6 ... main controller, 6a ... control unit, 6d ... store temperature sensor, 6e ... store humidity sensor, 6h ... timer unit.

Claims (8)

Cooling system comprising a plurality of refrigeration equipment that cools by controlling refrigerant intake into the evaporator, and a multi-chiller that changes the capacity in stages by selectively operating a plurality of compressors connected in parallel Because
Means for obtaining an in-store enthalpy based on the in-store temperature and in-store humidity and setting a stop suction pressure for each compressor according to the in-store enthalpy;
Means for driving the plurality of compressors on and off based on the set stop suction pressure for each compressor.
A cooling system characterized by that. Cooling system comprising a plurality of refrigeration equipment that cools by controlling refrigerant intake into the evaporator, and a multi-chiller that changes the capacity in stages by selectively operating a plurality of compressors connected in parallel Because
Means for setting the stop suction pressure for each compressor according to the day and time;
Means for driving the plurality of compressors on and off based on the set stop suction pressure for each compressor.
A cooling system characterized by that. Means for counting the number of ON / OFF times per predetermined time of each compressor when a plurality of compressors are ON / OFF driven based on the set stop suction pressure for each compressor;
Means for changing the stop suction pressure to a high stop suction pressure when the counted number of on / off operations is equal to or greater than a predetermined value;
The cooling system according to claim 1 or 2 characterized by things. Means for obtaining an average value per predetermined time of the actual suction pressure when the plurality of compressors are driven on and off based on the set stop suction pressure for each compressor;
Means for changing the stop suction pressure to a high stop suction pressure when the calculated average value is equal to or less than a predetermined value;
The cooling system according to claim 1 or 2 characterized by things. Means for recognizing the transition of the internal temperature of each refrigeration unit when driving a plurality of compressors on and off based on the set stop suction pressure for each compressor;
And further comprising means for changing the stop suction pressure to a low stop suction pressure when the recognized transition of the temperature in the actual warehouse tends to be higher than the set interior temperature.
The cooling system according to claim 1 or 2 characterized by things. Means for determining the presence or absence of a refrigeration unit that has entered defrosting when driving a plurality of compressors on and off based on the set stop suction pressure for each compressor;
Means for grasping the number and set temperature inside the refrigerator when there are refrigerated refrigerators that have entered defrosting;
Further comprising means for changing the stop suction pressure to a high stop suction pressure based on the number of refrigerated refrigeration equipment that has entered defrost and the set temperature in the refrigerator,
The cooling system according to claim 1 or 2 characterized by things. Means for determining the presence or absence of refrigeration equipment that has returned from defrosting when a plurality of compressors are driven on and off based on the set stop suction pressure for each compressor;
Means for grasping the number and the set temperature in the refrigerator when there is a refrigerated refrigeration apparatus restored from defrosting;
Further comprising means for changing the stop suction pressure to a low stop suction pressure based on the number of refrigerated refrigeration equipment restored from defrost and the set temperature in the refrigerator,
The cooling system according to claim 1 or 2 characterized by things. Means for determining the presence or absence of a refrigeration unit equipped with a night cover when driving a plurality of compressors on and off based on the set stop suction pressure for each compressor;
Means for grasping the number and the set temperature inside the refrigerator when there are refrigerated refrigerators equipped with night covers;
Further comprising means for changing the stop suction pressure to a high stop suction pressure based on the number of refrigerated refrigeration equipment fitted with a night cover and the set temperature in the refrigerator,
The cooling system according to claim 1 or 2 characterized by things.

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