JP2007107731A - Cooling system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling system capable of saving energy of an entire system by properly setting target suction pressures of a compressor in a business hour zone and a non-business hour zone, even when the system is installed in a shop such as a supermarket of which an opening time and a closing time are set. <P>SOLUTION: The target suction pressure PS of the compressor 5a is determined on the basis of an in-store enthalpy E determined on the basis of an in-store temperature TI and an in-store humidity UI, and a lowermost set temperature inside TS<SB>L</SB>among four showcases 1-4. Then a processing for correcting the target suction pressure PS previously determined, to a higher value is performed, when it is determined that a night cover NC is placed on the showcases 1-4. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a cooling system provided with a plurality of showcases with a built-in evaporator and a common refrigerator with a built-in compressor.

This type of cooling system includes a plurality of showcases installed in the store and a refrigerator that is shared by the plurality of showcases. Each showcase has an evaporator, a solenoid valve for taking the refrigerant into the evaporator, and a temperature sensor for detecting the temperature in the actual cabinet, and the solenoid valve is set so that the actual chamber temperature becomes the set chamber temperature. Controls opening and closing. The common refrigerator has a variable capacity compressor and a pressure sensor for detecting the actual suction pressure of the compressor, and the rotation speed of the compressor is adjusted so that the actual suction pressure becomes a separately set target suction pressure. Control.
JP-A-9-217974

  In the conventional cooling system, the target suction pressure is set based on the operating rate of the solenoid valve, the temperature drop speed, the average on / off cycle of the solenoid valve, etc. In addition, it is necessary to collect operation data, and a complicated process is required for the control device.

  In addition, in supermarkets, etc., where the opening time and closing time are set, measures are being taken to reduce the load by attaching a night cover to the showcase or turning off the showcase illuminator after the store closes. Since the load fluctuation due to disturbance is significantly reduced compared to the business hours, setting the target suction pressure using the same method as the business hours will result in the target suction pressure being too low, resulting in energy loss for compressor operation. There are difficulties that arise.

  The present invention was created in view of the above circumstances, and even when a system is installed in a store such as a supermarket that defines a store opening time and a store closing time, the target intake of the compressor in business hours and non-business hours An object of the present invention is to provide a cooling system that can appropriately set pressures to save energy of the entire system.

In order to achieve the above object, the present invention provides a cooling system including a plurality of showcases with a built-in evaporator and a shared refrigerator with a built-in compressor, and determines the enthalpy in the store based on the store temperature and the store humidity. , Means for setting the target suction pressure of the compressor based on the in-store enthalpy and the lowest set chamber temperature among the plurality of showcases, and the pressure between the set target suction pressure and the actual suction pressure of the compressor Means for controlling the rotational speed of the compressor so that the actual suction pressure becomes the target suction pressure based on the deviation, means for determining that the night cover is mounted on the showcase, and when it is determined that the night cover is mounted And a means for correcting the target suction pressure to a high value.
According to this cooling system, the in-store enthalpy is obtained based on the in-store temperature and the in-store humidity, and the target suction pressure of the compressor is accurately determined based on the in-store enthalpy and the lowest set inside temperature of the plurality of showcases. In other words, the target intake pressure of the compressor can be accurately set without collecting special operation data from each showcase and without requiring complicated processing etc. The difficulty in terms of surface can be eliminated and energy saving can be achieved. In addition, when it is determined that the night cover is attached to the showcase, the target suction pressure set earlier is corrected to a higher value than this, so load fluctuations due to disturbances compared to business hours It is possible to save energy by eliminating the problem that the target suction pressure becomes too low during non-business hours when the operating time is significantly reduced, causing energy loss in the operation of the compressor. In other words, even when the system is installed in a store such as a supermarket that defines the opening and closing times, the target suction pressure of the compressor is set appropriately in the business hours and non-business hours to save energy throughout the system. It is possible to provide a cooling system capable of achieving the above.

  Further, the present invention is a cooling system comprising a plurality of showcases with built-in evaporators having a lighting device and a common refrigerator with a built-in compressor, and determines the enthalpy in the store based on the store temperature and the store humidity, Means for setting a target suction pressure of the compressor based on the in-store enthalpy and the lowest set temperature in the plurality of showcases, and a pressure deviation between the set target suction pressure and the actual suction pressure of the compressor And a means for controlling the rotational speed of the compressor so that the actual suction pressure becomes the target suction pressure, a means for determining that the showcase illuminator is turned off, and the illuminator when it is determined that the illuminator is turned off. And a means for correcting the target suction pressure to a high value.

  According to this cooling system, the in-store enthalpy is obtained based on the in-store temperature and the in-store humidity, and the target suction pressure of the compressor is accurately determined based on the in-store enthalpy and the lowest set inside temperature of the plurality of showcases. In other words, the target intake pressure of the compressor can be accurately set without collecting special operation data from each showcase and without requiring complicated processing etc. The difficulty in terms of surface can be eliminated and energy saving can be achieved. In addition, when it is determined that the showcase lights have been extinguished, the target suction pressure set earlier is corrected to a higher value than this, so load fluctuations due to disturbances compared to business hours It is possible to save energy by eliminating the problem that the target suction pressure becomes too low during non-business hours when the operating time is significantly reduced, causing energy loss in the operation of the compressor. In other words, even when the system is installed in a store such as a supermarket that defines the opening and closing times, the target suction pressure of the compressor is set appropriately in the business hours and non-business hours to save energy throughout the system. It is possible to provide a cooling system capable of achieving the above.

  Furthermore, the present invention is a cooling system comprising a plurality of showcases with a built-in evaporator and a common refrigerator with a built-in compressor, determining the enthalpy in the store based on the in-store temperature and the in-store humidity, Means for setting the target suction pressure of the compressor based on the lowest set chamber temperature among a plurality of showcases, and actual suction based on the pressure deviation between the set target suction pressure and the actual suction pressure of the compressor Means for controlling the rotational speed of the compressor so that the pressure becomes the target suction pressure, means for judging that the night cover is attached to the showcase, and means for judging that the illuminator of the showcase is turned off And a means for correcting the target suction pressure to a high value when it is determined that at least one of night cover wearing and illuminator turn-off is provided.

  According to this cooling system, the in-store enthalpy is obtained based on the in-store temperature and the in-store humidity, and the target suction pressure of the compressor is accurately determined based on the in-store enthalpy and the lowest set inside temperature of the plurality of showcases. In other words, the target intake pressure of the compressor can be accurately set without collecting special operation data from each showcase and without requiring complicated processing etc. The difficulty in terms of surface can be eliminated and energy saving can be achieved. In addition, when it is determined that the night cover is attached to the showcase and / or when it is determined that the showcase illumination lamp is turned off, a process for correcting the previously set target suction pressure to a higher value than this is performed. As a result, the target suction pressure is too low during non-business hours when load fluctuations due to disturbances are significantly reduced compared to business hours, eliminating energy loss in compressor operation and saving energy. Can be planned. In other words, even when the system is installed in a store such as a supermarket that defines the opening and closing times, the target suction pressure of the compressor is set appropriately in the business hours and non-business hours to save energy throughout the system. It is possible to provide a cooling system capable of achieving the above.

  According to the present invention, even when the system is installed in a store such as a supermarket that defines the opening time and closing time, the target suction pressure of the compressor in the business hours and the non-business hours is set appropriately. A cooling system capable of saving energy of the entire system 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.

[First Embodiment]
1 to 6 show a first embodiment of the present invention. 1 is an overall configuration diagram of the cooling system, FIG. 2 is a side view of the showcase shown in FIG. 1, FIG. 3 is a diagram showing a processing flow for setting and correcting a target suction pressure, and FIG. FIG. 5 is a diagram showing a data table used when setting the target suction pressure, and FIG. 6 is a diagram showing a data table used when correcting the target suction pressure.

  Below, the whole structure of a cooling system is demonstrated with reference to FIG.1 and FIG.2. In FIG. 1, 1 to 4 are showcases, 5 is a common refrigerator, 6 is a control device, RP1 is a refrigerant forward pipe, RP2 is a refrigerant return pipe, and SL1 and SL2 are signal lines.

  Each of the showcases 1 to 4 is a type of showcase having openings 1h to 4h (see FIG. 2) for putting in and out of goods, and is installed at a predetermined position in a store such as a supermarket that defines the opening time and closing time. . Each showcase 1 to 4 includes evaporators 1a to 4a, expansion valves 1b to 4b provided on the inlet side of the evaporators 1a to 4a, and electromagnetic valves 1c to 1c provided on the inlet side of the expansion valves 1b to 4b. 4c, internal fans 1d to 4d for circulating the cooling air, internal temperature sensors 1e to 4e for detecting actual internal temperatures (blowing temperatures) TA1 to TA4, controllers 1f to 4f, settings The inside temperature setting devices 1g to 4g for determining the inside temperatures TS1 to TS4 are provided at least. 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 showcases 1 to 4 are connected in parallel to the refrigerant outlet and the refrigerant inlet of the common refrigerator 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 communication part, and a detection part, and each communication part is connected to control device 6 via signal line SL1, and internal temperature sensor 1e is connected to each detection part. -4e are connected. In the memory of the control unit of each controller 1f to 4f, the actual internal temperature (TA1) based on the temperature deviation (ΔT1 to ΔT4) between the set internal temperature (TS1 to TS4) and the actual internal temperature (TA1 to TA4). ~ TA4) Solenoid valve opening / closing program for controlling opening / closing of solenoid valves (1c ~ 4c) so that the set internal temperature (TS1 ~ TS4) becomes the set internal temperature (TS1 ~ TS4); The communication program etc. for transmitting temperature (TA1-TA4), temperature deviation ((DELTA) T1- (DELTA) T4), etc. to the control apparatus 6 are stored.

  As shown in FIG. 2, each showcase 1 to 4 is provided with a roll type night cover NC that covers the openings 1h to 4h in a non-sealed state. The night cover NC can be attached to the showcases 1 to 4 by pulling it down against the spring biasing force and engaging its lower end NCa with the case body, and by disengaging the lower end NCa. Automatic winding is possible. In addition, a plurality of shelf boards SB are installed in the storage chambers SC of the showcases 1 to 4 at intervals in the up and down direction, and display products are illuminated on the front end of the lower surface of each shelf board SB and the upper surface of the storage room SC. An illuminator IL such as a fluorescent lamp is provided.

  The common refrigerator 5 includes at least a compressor 5a of a type whose capacity is variable by increasing / decreasing the motor rotation speed, a condenser 5b, a pressure sensor 5c for detecting the actual suction pressure PA of the compressor 5a, and a controller 5d. Prepare. The common refrigerant 5 has an outlet for refrigerant (exit side of the condenser 5b) connected to the proximal end of the refrigerant forward pipe RP1, and an inlet for refrigerant (inlet side of the compressor 5a) connected to the end of the refrigerant return pipe RP2. Has been.

  The controller 5d includes a control unit having a microcomputer configuration, a communication unit, and a detection unit. The communication unit is connected to the control device 6 via a signal line SL2, and a pressure sensor 5c is connected to the detection unit. The memory of the controller of the controller 5d stores the compressor 5a so that the actual suction pressure PA becomes the target suction pressure PS based on the pressure deviation ΔP between the target suction pressure PS and the actual suction pressure PA set by the control device 6. A rotation speed variable program for controlling the rotation speed, a communication program for transmitting the actual suction pressure PA, the pressure deviation ΔP, and the like to the control device 6 are stored.

  The control device 6 detects a control unit 6a having a microcomputer configuration, a setting unit 6b including an input key 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 the heat from the showcases 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, the memory of the control unit 6a stores a program to be described later for setting and correcting the target suction pressure, a communication program for transmitting the set or corrected target suction pressure PS to the common refrigerator 5 and the like. Has been.

  Hereinafter, a processing flow relating to setting and correction of the target suction pressure executed by the control device 6 will be described with reference to FIGS.

  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. 3). Here, using the data table of FIG. 4 prepared in advance based on the relationship between the in-store temperature TI and the in-store humidity UI, the in-store enthalpy E is set 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 the data table of FIG.

After obtaining the store enthalpy E sets the target suction pressure PS of the compressor 5a based on the lowest within the set box temperature TS _L in this store enthalpy E and the four showcases 1-4 (FIG. 3 step S12). Here, using the data table of FIG. 5 prepared in advance based on the relationship between the store enthalpy E and the set chamber temperature T, the target suction pressure PS is set from the corresponding store enthalpy E and the set chamber temperature T. . Of course, this target suction pressure PS can also be obtained by a calculation formula using the in-store enthalpy E and the set inside temperature T as variables without using the data table of FIG.

  After setting the target suction pressure PS, the target suction pressure PS is transmitted to the common refrigerator 5 (step S13 in FIG. 3).

  The controller 5d of the common refrigerator 5 controls the rotation speed of the compressor 5a based on the pressure deviation ΔP between the target suction pressure PS and the actual suction pressure PA so that the actual suction pressure PA becomes the target suction pressure PS. That is, the controller 5d performs feedback control so that the actual suction pressure PA is decreased by increasing the number of rotations of the compressor 5a when the actual suction pressure PA> the target suction pressure PS, and the actual suction pressure PA <target suction pressure. In PS, feedback control is performed so that the actual suction pressure PA is increased by decreasing the rotational speed of the compressor 5a.

  On the other hand, the controllers 1f to 4f of the showcases 1 to 4 are based on the temperature difference (ΔT1 to ΔT4) between the set internal temperature (TS1 to TS4) and the actual internal temperature (TA1 to TA4). The opening / closing of the solenoid valves (1c to 4c) is controlled so that (TA1 to TA4) becomes the set internal temperature (TS1 to TS4). That is, each of the controllers 1f to 4f opens the solenoid valves (1c to 4c) to evaporate the refrigerant (1a to 4a) when the actual internal temperature (TA1 to TA4)> the set internal temperature (TS1 to TS4). ) And when the actual internal temperature (TA1 to TA4) <the set internal temperature (TS1 to TS4), the solenoid valves (1c to 4c) are closed and the refrigerant is introduced into the evaporators (1a to 4a). The opening and closing of the solenoid valves (1c to 4c) is controlled so as to suppress the above.

  After transmitting the target suction pressure PS to the common refrigerator 5, it is determined whether or not the night cover NC is attached to each showcase 1 to 4 (step S14 in FIG. 3).

For the night cover NC installation determination method,
(1) When the current time reaches a preset night cover wearing time (closed time or a time after a predetermined time from the closed time) and the cooling duration of each showcase is shorter than a preset reference cooling duration (2) Each night when the night cover attachment detection sensor (not shown) provided in each show case 1 detects a closure. Any of the methods for determining that the night cover NC- is attached to the showcases 1 to 4 can be adopted.

  The determination method of (1) is a method of recognizing that the night cover NC is forgotten to be installed using the fact that the cooling duration time is shorter than usual after the night cover NC is installed. The time can be grasped by the descent continuation time of the in-compartment temperatures TA1 to TA4, the opening continuation time of the solenoid valves 1b to 4b, and the like. Further, when an electronic expansion valve is used instead of the solenoid valve and the expansion valve, the same grasp can be made because the average opening degree of the electronic expansion valve is smaller than usual. .

When it is determined in step S14 that the night cover is attached, processing is performed to correct the previously set target suction pressure PS to a higher value (step S15 in FIG. 3). Here, using the data table of FIG. 6 prepared in advance based on the relationship between the in-store enthalpy E and the target suction pressure PS, the corrected target suction pressure PS is set from the current in-store enthalpy E. Lowermost solid line in Figure 6 shows a target suction pressure value that conforms to the temperature TS _L lowest setting box in the four showcases 1-4, the solid lines of the upper targets at night cover mounting Indicates the suction pressure value.

For example, when the store enthalpy E when it is determined that the night cover mounting is E11 is, TS _L compliant pressure value P11 pressure value night cover when mounted (corresponding to the set target suction pressure value PS in step S12) P12 And the pressure value P12 is set as the corrected target suction pressure value PS. Of course, the corrected target suction pressure value PS can be obtained by a calculation formula using the in-store enthalpy E and the target suction pressure value PS as variables without using the data table of FIG.

  After setting the corrected target suction pressure PS, the corrected target suction pressure PS is transmitted to the common refrigerator 5 (step S16 in FIG. 3).

  Based on the pressure deviation ΔP between the corrected target suction pressure PS and the actual suction pressure PA, the controller 5d of the common refrigerator 5 performs compression so that the actual suction pressure becomes the corrected target suction pressure as described above. The rotation speed of the machine 5a is controlled.

  When it is determined in step S14 that the night cover is not mounted, or when it is determined in step S14 that the night cover is not mounted after it is determined that the night cover is mounted, the processes of steps S11 to S13 are repeated.

Thus, according to the above-described cooling system, the in-store enthalpy E is obtained based on the in-store temperature TI and the in-store humidity UI, and the in-store enthalpy E and the lowest setting in the four showcases 1 to 4 are stored. can be set accurately target suction pressure PS of the compressor 5a based on the temperature TS _L, in other words, without collecting special operating data from each showcase 1 to 4, and, complicated control device 6 Since the target suction pressure PS of the compressor 5a can be accurately set without requiring any processing or the like, it is possible to eliminate the difficulty in cost and to save energy.

  Further, according to the above-described cooling system, when it is determined that the night cover NC is attached to each of the showcases 1 to 4, the target suction pressure PS set previously is corrected to a higher value than this. As a result, the target suction pressure PS becomes too low in non-business hours when load fluctuations due to disturbances are significantly reduced compared to the business hours, eliminating the problem of energy loss in the operation of the compressor 5a and saving energy. Can be planned.

  That is, even when the system is installed in a store such as a supermarket that defines the opening time and closing time, the target suction pressure of the compressor 5a in the business hours and the non-business hours is set appropriately, respectively. A cooling system capable of saving energy can be provided.

  In the first embodiment described above, the processing of steps S11 to S13 is performed when it is determined that the night cover is not mounted in step S14 after the night cover is mounted, but the corrected target suction pressure PS is set. Based on the control of the rotational speed of the compressor 5a, the corrected target suction pressure PS becomes the corrected target suction pressure PS when the internal temperature of at least one showcase exceeds the set internal temperature. A processing step for returning may be added to the flow of FIG.

  In the first embodiment described above, the case where the night covers NC are attached to all the showcases 1 to 4 has been described as an example, but the four showcases 1 to 4 are, for example, 2 ° C. and 3 ° C. When the night cover NC is attached only to the 3 ° C showcase that is divided by the set internal temperature, the target suction pressure value P11 compliant with 3 ° C shown in Fig. 6 is compliant with 5 ° C indicated by a broken line in the same figure. The pressure value P13 (a value lower than P12) may be corrected so as not to cause insufficient cooling in the 5 ° C. showcase.

  Furthermore, in the first embodiment described above, the cooling system provided with four showcases 1 to 4 is exemplified, but the present invention can be applied by applying the present invention even if the number of showcases is five or more. Similar effects can be obtained.

[Second Embodiment]
7 and 8 show a second embodiment of the present invention. FIG. 7 is a diagram showing a processing flow relating to setting and correction of the target suction pressure, and FIG. 8 is a diagram showing a data table used when correcting the target suction pressure. The overall structure of the cooling system, the side of the showcase, the data table used when determining the in-store enthalpy, and the data table used when setting the target suction pressure are shown in FIGS. 1, 2, 4 and 5. Therefore, in this description, the same figure is cited and the individual description is omitted.

  Hereinafter, a processing flow relating to setting and correction of the target suction pressure executed by the control device 6 will be described with reference to FIGS.

  After the system is activated, 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 S21 in FIG. 7). Here, using the data table of FIG. 4 prepared in advance based on the relationship between the in-store temperature TI and the in-store humidity UI, the in-store enthalpy E is set 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 the data table of FIG.

After obtaining the store enthalpy E sets the target suction pressure PS of the compressor 5a based on the lowest within the set box temperature TS _L in this store enthalpy E and the four showcases 1-4 (FIG. 7 step S22). Here, using the data table of FIG. 5 prepared in advance based on the relationship between the store enthalpy E and the set chamber temperature T, the target suction pressure PS is set from the corresponding store enthalpy E and the set chamber temperature T. . Of course, this target suction pressure PS can also be obtained by a calculation formula using the in-store enthalpy E and the set inside temperature T as variables without using the data table of FIG.

  After setting the target suction pressure PS, the target suction pressure PS is transmitted to the common refrigerator 5 (step S23 in FIG. 7).

  The controller 5d of the common refrigerator 5 controls the rotation speed of the compressor 5a based on the pressure deviation ΔP between the target suction pressure PS and the actual suction pressure PA so that the actual suction pressure PA becomes the target suction pressure PS. That is, the controller 5d performs feedback control so that the actual suction pressure PA is decreased by increasing the number of rotations of the compressor 5a when the actual suction pressure PA> the target suction pressure PS, and the actual suction pressure PA <target suction pressure. In PS, feedback control is performed so that the actual suction pressure PA is increased by decreasing the rotational speed of the compressor 5a.

  On the other hand, the controllers 1f to 4f of the showcases 1 to 4 are based on the temperature difference (ΔT1 to ΔT4) between the set internal temperature (TS1 to TS4) and the actual internal temperature (TA1 to TA4). The opening / closing of the solenoid valves (1c to 4c) is controlled so that (TA1 to TA4) becomes the set internal temperature (TS1 to TS4). That is, each of the controllers 1f to 4f opens the solenoid valves (1c to 4c) to evaporate the refrigerant (1a to 4a) when the actual internal temperature (TA1 to TA4)> the set internal temperature (TS1 to TS4). ) And when the actual internal temperature (TA1 to TA4) <the set internal temperature (TS1 to TS4), the solenoid valves (1c to 4c) are closed and the refrigerant is introduced into the evaporators (1a to 4a). The opening and closing of the solenoid valves (1c to 4c) is controlled so as to suppress the above.

  After transmitting the target suction pressure PS to the shared refrigerator 5, it is determined whether or not the illuminators IL of the showcases 1 to 4 are turned off (step S24 in FIG. 7).

In the method for determining whether the illuminator IL is turned off,
(1) A method for determining that the illuminators IL of the showcases 1 to 4 are turned off when the present time reaches a preset lighting time and a turn-off signal is input to each showcase 1 to 4 (2) Any method of determining that the illuminators IL of the showcases 1 to 4 are turned off when the illumination switches (not shown) provided in the showcases 1 to 4 are switched off can be adopted.

  In order to realize the determination method of (1), when the current time reaches a preset lighting time, a lighting signal is output to each of the showcases 1 to 4 and when the current time reaches a preset lighting time. Means for outputting a turn-off signal to each showcase 1 to 4 is provided in the control device 6, and means for turning on the illuminator IL based on the input of the turn-on signal and turning off the illuminator IL based on the input of the turn-off signal. What is necessary is just to provide in showcases 1-4.

  In order to realize the determination method (2), each of the showcases 1 to 4 needs to have an illumination switch (not shown) for switching the illuminator IL on or off. Since a switch is provided in advance, an existing switch and its signal may be used.

When it is determined in step S24 that the illuminator is extinguished, processing is performed to correct the previously set target suction pressure PS to a higher value (step S25 in FIG. 7). Here, using the data table of FIG. 8 prepared in advance based on the relationship between the in-store enthalpy E and the target inhalation pressure PS, the corrected target inhalation pressure PS is set from the current in-store enthalpy E. Lowermost solid line in FIG. 8 shows a target suction pressure value that conforms to the temperature TS _L lowest setting box in the four showcases 1-4, the solid lines of the upper target during the illuminator off Indicates the suction pressure value.

For example, when the store enthalpy E when it is determined that the illuminator off of E21 is, TS _L compliant pressure value P21 pressure value when the illuminator off (corresponding to the set target suction pressure value PS in step S22) P22 The pressure value P22 is set as the corrected target suction pressure value PS. Of course, the corrected target suction pressure value PS can be obtained by a calculation formula using the in-store enthalpy E and the target suction pressure value PS as variables without using the data table of FIG.

  After the corrected target suction pressure PS is set, the corrected target suction pressure PS is transmitted to the common refrigerator 5 (step S26 in FIG. 7).

  Based on the pressure deviation ΔP between the corrected target suction pressure PS and the actual suction pressure PA, the controller 5d of the common refrigerator 5 performs compression so that the actual suction pressure becomes the corrected target suction pressure as described above. The rotation speed of the machine 5a is controlled.

  If it is determined in step S24 that the illuminator is not extinguished, or if it is determined in step S24 that the illuminator is not extinguished after it is determined that the illuminator is extinguished, the processes in steps S21 to S23 are repeated.

Thus, according to the above-described cooling system, the in-store enthalpy E is obtained based on the in-store temperature TI and the in-store humidity UI, and the in-store enthalpy E and the lowest setting in the four showcases 1 to 4 are stored. can be set accurately target suction pressure PS of the compressor 5a based on the temperature TS _L, in other words, without collecting special operating data from each showcase 1 to 4, and, complicated control device 6 Since the target suction pressure PS of the compressor 5a can be accurately set without requiring any processing or the like, it is possible to eliminate the difficulty in cost and to save energy.

  Moreover, according to the above-described cooling system, when it is determined that the illumination lamps IL of the respective showcases 1 to 4 are turned off, the target suction pressure PS set previously is corrected to a higher value than this. As a result, the target suction pressure PS becomes too low in non-business hours when load fluctuations due to disturbances are significantly reduced compared to the business hours, eliminating the problem of energy loss in the operation of the compressor 5a and saving energy. Can be planned.

  That is, even when the system is installed in a store such as a supermarket that defines the opening time and closing time, the target suction pressure of the compressor 5a in the business hours and the non-business hours is set appropriately, respectively. A cooling system capable of saving energy can be provided.

  In the second embodiment described above, the processing of steps S21 to S23 is performed when it is determined in step S24 that the illuminator is not extinguished after the illuminator is extinguished. Based on the control of the rotational speed of the compressor 5a, the corrected target suction pressure PS becomes the corrected target suction pressure PS when the internal temperature of at least one showcase exceeds the set internal temperature. A processing step for returning may be added to the flow of FIG.

  In the second embodiment described above, the cooling system including four showcases 1 to 4 is exemplified. However, even if the number of showcases is five or more, the present invention is applied to the cooling system. Similar effects can be obtained.

[Third Embodiment]
9 and 10 show a third embodiment of the present invention. FIG. 9 is a diagram showing a processing flow relating to setting and correction of the target suction pressure, and FIG. 9 is a diagram showing a data table used when correcting the target suction pressure. The overall structure of the cooling system, the side of the showcase, the data table used when determining the in-store enthalpy, and the data table used when setting the target suction pressure are shown in FIGS. 1, 2, 4 and 5. Therefore, in this description, the same figure is cited and the individual description is omitted.

  Hereinafter, a processing flow relating to setting and correction of the target suction pressure executed by the control device 6 will be described with reference to FIGS.

  After the system is activated, 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 S31 in FIG. 9). Here, using the data table of FIG. 4 prepared in advance based on the relationship between the in-store temperature TI and the in-store humidity UI, the in-store enthalpy E is set 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 the data table of FIG.

After obtaining the store enthalpy E sets the target suction pressure PS of the compressor 5a based on the lowest within the set box temperature TS _L in this store enthalpy E and the four showcases 1-4 (FIG. 9 step S32). Here, using the data table of FIG. 5 prepared in advance based on the relationship between the store enthalpy E and the set chamber temperature T, the target suction pressure PS is set from the corresponding store enthalpy E and the set chamber temperature T. . Of course, this target suction pressure PS can also be obtained by a calculation formula using the in-store enthalpy E and the set inside temperature T as variables without using the data table of FIG.

  After setting the target suction pressure PS, the target suction pressure PS is transmitted to the common refrigerator 5 (step S33 in FIG. 9).

  The controller 5d of the common refrigerator 5 controls the rotation speed of the compressor 5a based on the pressure deviation ΔP between the target suction pressure PS and the actual suction pressure PA so that the actual suction pressure PA becomes the target suction pressure PS. That is, the controller 5d performs feedback control so that the actual suction pressure PA is decreased by increasing the number of rotations of the compressor 5a when the actual suction pressure PA> the target suction pressure PS, and the actual suction pressure PA <target suction pressure. In PS, feedback control is performed so that the actual suction pressure PA is increased by decreasing the rotational speed of the compressor 5a.

  On the other hand, the controllers 1f to 4f of the showcases 1 to 4 are based on the temperature difference (ΔT1 to ΔT4) between the set internal temperature (TS1 to TS4) and the actual internal temperature (TA1 to TA4). The opening / closing of the solenoid valves (1c to 4c) is controlled so that (TA1 to TA4) becomes the set internal temperature (TS1 to TS4). That is, each of the controllers 1f to 4f opens the solenoid valves (1c to 4c) to evaporate the refrigerant (1a to 4a) when the actual internal temperature (TA1 to TA4)> the set internal temperature (TS1 to TS4). ) And when the actual internal temperature (TA1 to TA4) <the set internal temperature (TS1 to TS4), the solenoid valves (1c to 4c) are closed and the refrigerant is introduced into the evaporators (1a to 4a). The opening and closing of the solenoid valves (1c to 4c) is controlled so as to suppress the above.

  After transmitting the target suction pressure PS to the common refrigerator 5, it is determined whether or not the night cover NC is attached to each of the showcases 1 to 4 and whether or not the illuminators IL of the showcases 1 to 4 are turned off. (Steps S34 to S36 in FIG. 9).

For the night cover NC installation determination method,
(1) When the current time reaches a preset night cover wearing time (closed time or a time after a predetermined time from the closed time) and the cooling duration of each showcase is shorter than a preset reference cooling duration (2) Each night when the night cover attachment detection sensor (not shown) provided in each show case 1 detects a closure. Any of the methods for determining that the night cover NC- is attached to the showcases 1 to 4 can be adopted.

  The determination method of (1) is a method of recognizing that the night cover NC is forgotten to be installed using the fact that the cooling duration time is shorter than usual after the night cover NC is installed. The time can be grasped by the descent continuation time of the in-compartment temperatures TA1 to TA4, the opening continuation time of the solenoid valves 1b to 4b, and the like. Further, when an electronic expansion valve is used instead of the solenoid valve and the expansion valve, the same grasp can be made because the average opening degree of the electronic expansion valve is smaller than usual. .

On the other hand, in the method for determining whether the illuminator IL is turned off,
(3) A method of determining that the illuminators IL of the showcases 1 to 4 are turned off when the present time reaches a preset lighting time and a turn-off signal is input to each showcase 1 to 4 (4) Any method of determining that the illuminators IL of the showcases 1 to 4 are turned off when the illumination switches (not shown) provided in the showcases 1 to 4 are switched off can be adopted.

  In order to realize the determination method (3), when the current time reaches a preset lighting time, a lighting signal is output to each of the showcases 1 to 4, and when the current time reaches a preset lighting time. Means for outputting a turn-off signal to each showcase 1 to 4 is provided in the control device 6, and means for turning on the illuminator IL based on the input of the turn-on signal and turning off the illuminator IL based on the input of the turn-off signal. What is necessary is just to provide in showcases 1-4.

  In order to realize the determination method of (4), each showcase 1 to 4 needs to have an illumination switch (not shown) for switching the illuminator IL on or off. Since a switch is provided in advance, an existing switch and its signal may be used.

When it is determined in steps S34 to S36 that at least one of night cover attachment and illuminator extinction is determined, processing is performed to correct the previously set target suction pressure PS to a higher value (step S37 in FIG. 9). Here, using the data table of FIG. 10 prepared in advance based on the relationship between the in-store enthalpy E and the target inhalation pressure PS, the corrected target inhalation pressure PS is set from the current in-store enthalpy E. Lowermost solid line in FIG. 10 shows a target suction pressure value that conforms to the lowest set temperature TS _L in the four showcases 1-4, the target at the time of the upper solid line illuminator off The suction pressure value indicates the target suction pressure value when the night cover is mounted, and the upper solid line indicates the target suction pressure value when the night cover is mounted and when the illuminator is turned off.

For example, when the store enthalpy E when it is determined that the illuminator off of E31 is, TS _L compliant pressure value P31 pressure value when the illuminator off (corresponding to the set target suction pressure value PS in step S32) P32 And the pressure value P32 is set as the corrected target suction pressure value PS. Of course, the corrected target suction pressure value PS can also be obtained by a calculation formula using the in-store enthalpy E and the target suction pressure value PS as variables without using the data table of FIG.

Further, when the store enthalpy E when it is determined that the night cover mounting is E31 is, TS _L compliant pressure value P31 pressure value night cover when mounted (corresponding to the set target suction pressure value PS in step S32) P33 The pressure value P33 is set as the corrected target suction pressure value PS. Of course, the corrected target suction pressure value PS can also be obtained by a calculation formula using the in-store enthalpy E and the target suction pressure value PS as variables without using the data table of FIG.

Further, when the store enthalpy E when it is determined that the illuminator off & Night cover mounting is E31, the pressure value of compliant TS _L P31 (corresponding to the target suction pressure value PS set in step S32) when a night cover mounting & Replace with the pressure value P34 when the illuminator is turned off, and set the pressure value P34 as the corrected target suction pressure value PS. Of course, the corrected target suction pressure value PS can also be obtained by a calculation formula using the in-store enthalpy E and the target suction pressure value PS as variables without using the data table of FIG.

  After the corrected target suction pressure PS is set, the corrected target suction pressure PS is transmitted to the common refrigerator 5 (step S37 in FIG. 9).

  Based on the pressure deviation ΔP between the corrected target suction pressure PS and the actual suction pressure PA, the controller 5d of the common refrigerator 5 performs compression so that the actual suction pressure becomes the corrected target suction pressure as described above. The rotation speed of the machine 5a is controlled.

  When it is determined in steps S34 to S36 that at least one of night cover attachment and illuminator extinction is determined, and after it is determined that at least one of night cover attachment and illuminator extinction is set, night cover non-attachment and illuminator are determined in steps S34 to S36. When it is determined that the light is not turned off, the processes in steps S31 to S33 are repeated.

Thus, according to the above-described cooling system, the in-store enthalpy E is obtained based on the in-store temperature TI and the in-store humidity UI, and the in-store enthalpy E and the lowest setting in the four showcases 1 to 4 are stored. can be set accurately target suction pressure PS of the compressor 5a based on the temperature TS _L, in other words, without collecting special operating data from each showcase 1 to 4, and, complicated control device 6 Since the target suction pressure PS of the compressor 5a can be accurately set without requiring any processing or the like, it is possible to eliminate the difficulty in cost and to save energy.

  Further, according to the cooling system described above, when it is determined that the night cover NC is attached to each showcase 1 to 4 and / or when it is determined that the illumination lamp IL of each showcase 1 to 4 is turned off. Since the previously set target suction pressure PS is corrected to a higher value than this, the target suction pressure PS is too low in non-business hours when load fluctuations due to disturbance are significantly reduced compared to business hours. It becomes a value and the difficulty which produces an energy loss in the driving | operation of the compressor 5a can be eliminated, and energy saving can be aimed at.

  That is, even when the system is installed in a store such as a supermarket that defines the opening time and closing time, the target suction pressure of the compressor 5a in the business hours and the non-business hours is set appropriately, respectively. A cooling system capable of saving energy can be provided.

  In the above-described third embodiment, when it is determined that the night cover is not mounted and the illuminator is not turned off in steps S34 to S36 after it is determined that the night cover is attached or the illuminator is turned off, steps S31 to S33 are performed. Although the processing is shown, the inside temperature of at least one showcase exceeds the set inside temperature in a state where the rotation speed of the compressor 5a is controlled based on the corrected target suction pressure PS. A processing step for returning the corrected target suction pressure PS to the target suction pressure PS before correction may be added to the flow of FIG.

  In the above-described third embodiment, the case where the night covers NC are attached to all the showcases 1 to 4 has been described as an example. However, the four showcases 1 to 4 are, for example, 2 ° C. and 3 ° C. When the night cover NC is attached only to a 3 ° C showcase that is divided by two set chamber temperatures, the target suction pressure value P31 compliant with 3 ° C shown in FIG. The pressure value P35 (a value lower than P33) may be corrected so as not to cause insufficient cooling in the 5 ° C. showcase.

  Furthermore, in the above-described third embodiment, the cooling system including four showcases 1 to 4 has been exemplified. However, the present invention can be applied to a cooling system in which the number of showcases is five or more. Similar effects can be obtained.

1 is an overall configuration diagram of a cooling system according to a first embodiment of the present invention. It is a side view of the showcase shown in FIG. It is a figure which shows the processing flow concerning the setting and correction | amendment of target suction pressure. It is a figure which shows the data table used when calculating | requiring an in-store enthalpy. It is a figure which shows the data table used when setting target suction pressure. It is a figure which shows the data table used when correcting a target suction pressure. It is a figure which shows the processing flow which concerns on the setting and correction | amendment of the target suction pressure which concerns on 2nd Embodiment of this invention. It is a figure which shows the data table used when correcting a target suction pressure. It is a figure which shows the processing flow which concerns on the setting and correction | amendment of the target suction pressure which concerns on 3rd Embodiment of this invention. It is a figure which shows the data table used when correcting a target suction pressure.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1-4 ... Refrigerated refrigeration equipment, 1a-4a ... Evaporator, 1b-4b ... Expansion valve, 1c-4c ... Solenoid valve, 1e-4e ... Inside temperature sensor, 1f-4f ... Controller, 1h-4h ... Opening, NC ... Night cover, IL ... Illuminator, 5 ... Shared refrigerator, 5a ... Compressor, 5c ... Pressure sensor, 5d ... Controller, 6 ... Controller, 6a ... Control part, 6d ... In-store temperature sensor, 6e ... In-store humidity Sensor, RP1 ... refrigerant forward pipe, RP2 ... refrigerant return pipe, SL1, SL2 ... signal line.

Claims (14)

A cooling system comprising a plurality of showcases with built-in evaporators and a common refrigerator with a built-in compressor,
Means for determining an in-store enthalpy based on the in-store temperature and in-store humidity, and setting a target suction pressure of the compressor based on the in-store enthalpy and the lowest set in-case temperature among a plurality of showcases;
Means for controlling the rotational speed of the compressor so that the actual suction pressure becomes the target suction pressure based on a pressure deviation between the set target suction pressure and the actual suction pressure of the compressor;
Means for determining that the night cover is attached to the showcase;
Means for correcting the target suction pressure to a high value when it is determined that the night cover is mounted,
A cooling system characterized by that. The means for determining that the night cover is attached to the showcase is when the current time reaches the preset night cover attachment time and the showcase cooling duration is shorter than the preset reference cooling duration. It is determined that the night cover is attached to the showcase,
The cooling system according to claim 1. The means for determining that the night cover is attached to the showcase is determined that the night cover is attached to the showcase when the night cover attachment detection sensor provided in the showcase detects the attachment.
The cooling system according to claim 1. The inside of at least one showcase with the compressor speed controlled so that the actual suction pressure becomes the target suction pressure based on the pressure deviation between the corrected target suction pressure and the actual suction pressure of the compressor A means for returning the corrected target suction pressure to the target suction pressure before correction when the temperature exceeds the set internal temperature;
The cooling system according to any one of claims 1 to 3. A cooling system comprising a plurality of showcases with built-in evaporators having an illuminator and a common refrigerator with a built-in compressor,
Means for determining an in-store enthalpy based on the in-store temperature and in-store humidity, and setting a target suction pressure of the compressor based on the in-store enthalpy and the lowest set in-case temperature among a plurality of showcases;
Means for controlling the rotational speed of the compressor so that the actual suction pressure becomes the target suction pressure based on a pressure deviation between the set target suction pressure and the actual suction pressure of the compressor;
Means for determining that the showcase illuminator has been turned off;
Means for correcting the target suction pressure to a high value when it is determined that the illuminator is extinguished,
A cooling system characterized by that. A means for outputting a lighting signal to each showcase when the current time reaches a preset lighting time and outputting a lighting signal to the showcase when the current time reaches a preset lighting time;
Each showcase has means for turning on the illuminator based on the input of the lighting signal and turning off the illuminator based on the input of the extinction signal,
The means for determining that the showcase illuminator is turned off determines that the showcase illuminator is turned off when a turn-off signal is input to the showcase.
The cooling system according to claim 5. Each showcase has a lighting switch to switch the illuminator on or off,
The means for determining that the illuminator of the showcase is turned off determines that the illuminator of the showcase is turned off when the illumination switch provided in the showcase is switched off.
The cooling system according to claim 5. The inside of at least one showcase with the compressor speed controlled so that the actual suction pressure becomes the target suction pressure based on the pressure deviation between the corrected target suction pressure and the actual suction pressure of the compressor A means for returning the corrected target suction pressure to the target suction pressure before correction when the temperature exceeds the set internal temperature;
The cooling system according to any one of claims 5 to 7, wherein A cooling system comprising a plurality of showcases with built-in evaporators and a common refrigerator with a built-in compressor,
Means for determining an in-store enthalpy based on the in-store temperature and in-store humidity, and setting a target suction pressure of the compressor based on the in-store enthalpy and the lowest set in-case temperature among a plurality of showcases;
Means for controlling the rotational speed of the compressor so that the actual suction pressure becomes the target suction pressure based on a pressure deviation between the set target suction pressure and the actual suction pressure of the compressor;
Means for determining that the night cover is attached to the showcase;
Means for determining that the showcase illuminator has been turned off;
Means for correcting the target suction pressure to a high value when determined to be at least one of night cover wearing and illuminator extinction,
A cooling system characterized by that. The means for determining that the night cover is attached to the showcase is when the current time reaches the preset night cover attachment time and the showcase cooling duration is shorter than the preset reference cooling duration. It is determined that the night cover is attached to the showcase,
The cooling system according to claim 9. The means for determining that the night cover is attached to the showcase is determined that the night cover is attached to the showcase when the night cover attachment detection sensor provided in the showcase detects the attachment.
The cooling system according to claim 9. A means for outputting a lighting signal to each showcase when the current time reaches a preset lighting time and outputting a lighting signal to each showcase when the current time reaches a preset lighting time;
Each showcase has means for turning on the illuminator based on the input of the lighting signal and turning off the illuminator based on the input of the extinction signal,
The means for determining that the showcase illuminator is turned off determines that the showcase illuminator is turned off when a turn-off signal is input to the showcase.
The cooling system according to any one of claims 9 to 11. Each showcase has a lighting switch to switch the illuminator on or off,
The means for determining that the showcase illuminator is turned off determines that the showcase illuminator is turned off when the illumination switch provided in the showcase is switched to the off state.
The cooling system according to any one of claims 9 to 11. The inside of at least one showcase with the compressor speed controlled so that the actual suction pressure becomes the target suction pressure based on the pressure deviation between the corrected target suction pressure and the actual suction pressure of the compressor Means for returning the corrected target suction pressure to the target suction pressure before correction when the temperature exceeds the set internal temperature;
The cooling system according to any one of claims 9 to 13.

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