JP5912891B2 - Power saving operation method and apparatus for refrigerated warehouse - Google Patents

Description

  The present invention relates to a refrigerated warehouse suitable for a refrigerated warehouse having a plurality of cooling chambers and a power saving operation method thereof.

  From the viewpoint of global environmental conservation, refrigeration equipment using natural refrigerants has been reviewed. Among natural refrigerants, NH3 has an ozone depletion coefficient of zero, a global warming coefficient of almost zero, and excellent refrigerant performance. However, since NH3 is toxic to the human body, NH3 is used as a primary refrigerant, it is also a natural refrigerant, a relatively safe, and a refrigerator using CO2 as a secondary refrigerant, which has excellent characteristics as a medium for carrying heat. Is widely adopted. Patent Literature 1 and Patent Literature 2 disclose that such a refrigeration apparatus is used for cooling a showcase, indoor air conditioning, or the like.

  Although the refrigeration apparatus is also used in the refrigerated warehouse, most of the expense of the refrigerated warehouse is a power charge spent for operating the refrigerator. Therefore, cost reduction can be achieved by saving power. In addition, there is a risk of power supply shortage during peak hours of summertime power consumption, and power saving is also required in the field of cold storage. Therefore, at present, efforts are being made to save power by improving the efficiency of the equipment and conducting frequent operation management.

  The CO2 brine cooled and liquefied by the refrigeration apparatus using NH3 as a primary refrigerant is temporarily stored in a liquid reservoir and then sent to a refrigerated warehouse via a conduit. The CO2 brine solution is supplied to an air cooler provided in a refrigerated warehouse, and cools indoor air with the air cooler. There, part is gasified and returns to the reservoir via a conduit. In a refrigerated warehouse having a plurality of cooling chambers, the air temperature in each cooling chamber is detected, and when the set temperature is about to be exceeded, the air cooler is operated to cool the indoor air. At this time, if the pressure of the CO2 piping system rises and exceeds the set value, the refrigerator is operated to cool the CO2 brine.

  On the other hand, as part of energy saving in summer, the cooling rooms are sufficiently cooled at night, and the refrigerator is stopped during the daytime when the power peak occurs by using the heat storage effect of luggage and buildings. It has been broken.

JP 2002-243350 A JP 2011-196607 A

  However, such a method is effective in a storage-type refrigerated warehouse with a small amount of luggage being taken in and out in the daytime. However, in view of the safety width, it may be cooled more than necessary at night, which may not save energy. On the other hand, the daytime load may increase to exceed the allowable temperature of the cooling chamber. In particular, logistics-type refrigerated warehouses, which have been increasing recently, tend to have such problems because of heavy loading and unloading.

  In view of the problems of the prior art, the present invention reduces power consumption even in a refrigerated warehouse having a high-load type cooling chamber in which the storage of cold-reserved items is intense and the daytime cooling load is large, such as a distribution-type refrigerated warehouse. An object of the present invention is to make it possible to stop the refrigerator without exceeding the set temperature of the cooling room at the time of daytime power peak.

  In order to achieve such an object, the power-saving operation method of the refrigerated warehouse according to the present invention includes a plurality of cooling chambers including a high-load type cooling chamber in which the cold-reserved product is frequently taken in and out and a storage-type cooling chamber in which the cold-reserved product is low in / out In the power-saving operation method of the refrigerated warehouse, each of the first steps of producing the CO2 brine liquid with a refrigerator constituting the refrigeration cycle, and supplying the CO2 brine liquid to an air cooler respectively provided in each cooling chamber The second step of cooling the cooling chamber to the first set temperature and the time when the refrigerator is operated in a time zone other than the time zone in which the power consumption reaches a peak, and the CO2 brine can be liquefied below the first set temperature. The third step of cooling each cooling chamber to the second set temperature, and the operation of the refrigerator was stopped in a time zone including a time zone in which the power consumption peaked, and the temperature became higher than the first set temperature. In the air cooler of the high load cooling room, Supplying cooled liquefied CO2 brine solution in the mold cooling chamber, it is made of a fourth step of returning the temperature of the high load type cooling chamber to the first set temperature.

  The present invention is directed to a refrigerated warehouse having a plurality of cooling chambers including a high-load cooling chamber and a storage-type cooling chamber. The first setting that is the normal cooling temperature of the cooling room when the refrigerator is operated in a time zone other than the time zone in which the power consumption is peak, such as at night, for example, in a time zone in which the power consumption is low such as at night The cooling chamber is cooled to a second set temperature lower than the temperature and capable of liquefying the CO2 brine. Then, the operation of the refrigerator is stopped in a time zone including a time zone in which daytime power consumption is at its peak. During this time, when the high load type cooling chamber becomes higher than the first set temperature, CO2 brine is supplied to the air cooler of the storage type cooling chamber, and the CO2 brine is cooled and liquefied by the heat storage effect of the storage type cooling chamber. To do. This cooled and liquefied CO2 brine solution is supplied to the high load type cooling chamber to be cooled, and the high load type cooling chamber is returned to the first set temperature.

  Thereby, even when the refrigerator is stopped, each cooling chamber can be maintained at the first set temperature, including the high-load type cooling chamber whose temperature is likely to rise. In addition, the high load cooling chamber is cooled using the heat storage effect of the storage refrigerated warehouse, and the second set temperature is set to a temperature that is not overcooled, so that power saving can be achieved. As a result, even in a refrigerated warehouse having a high-load type cooling chamber, the cooling chamber can be maintained at the first set temperature while stopping the operation of the refrigerator at the daytime power peak while enabling power saving.

  Further, the refrigerated warehouse of the present invention that can be directly used for the implementation of the method of the present invention includes a plurality of cooling chambers including a high-load type cooling chamber with a large number of items to be taken in and out and a storage type cooling chamber with a few items to be taken in and out. In a refrigerated warehouse having a chamber, a refrigerator constituting a refrigeration cycle, a CO2 reservoir for storing the CO2 brine liquid cooled by the refrigerator, an air cooler provided in each cooling chamber, and a CO2 solution CO2 circulation path for supplying the CO2 brine liquid from the reservoir to each air cooler, a liquid pump provided in the forward path of the CO2 circulation path for supplying the CO2 brine liquid from the CO2 liquid reservoir to the air cooler, and each cooling chamber And a CO2 brine supply path for supplying the CO2 brine liquid branched from the CO2 circulation path and liquefied in the storage-type cooling chamber to the high-load cooling chamber.

  In the refrigerated warehouse of the present invention, a second set temperature that is lower than the first set temperature that is the normal cooling temperature and that can liquefy the CO2 brine is set, and in a time zone other than the time zone in which the power consumption peaks. For example, the refrigerator is operated in a time zone where the power consumption is small, such as at night, and the plurality of cooling chambers are cooled to the second set temperature. Then, during the time when the daytime power consumption is at its peak, the operation of the refrigerator is stopped. During this time, if the high-load cooling room exceeds the first set temperature, the heat storage effect of other storage-type cooling rooms The CO2 brine cooled and liquefied by is supplied to the high-load cooling chamber. Thereby, the high load type cooling chamber is cooled and returned to the first set temperature. Therefore, even when the refrigerator is stopped, all the cooling chambers can be maintained at the first set temperature.

  As described above, the heat storage effect of the storage-type refrigerated warehouse is used, and the second set temperature is set to a temperature that does not cause excessive cooling, so that power saving can be achieved. Therefore, even in a refrigerated warehouse having a high-load type cooling room, the cooling room can be maintained at the first set temperature while stopping the operation of the refrigerator at the time of daytime power peak while enabling power saving.

  In the present invention, the high load type cooling chamber is on a lower floor than the storage type cooling chamber, the CO2 liquid reservoir is disposed below each cooling chamber, and the CO2 brine liquid supply path is an air cooler of the storage type cooling chamber. The CO2 flow direction upstream of the CO2 circuit may be branched from the forward path of the CO2 circulation path and connected to the CO2 reservoir. As a result, the CO2 brine liquid cooled and liquefied by the heat storage effect of the storage-type cooling chamber is allowed to naturally flow down to the CO2 liquid reservoir by gravity, and then the CO2 brine liquid that has flowed down to the CO2 liquid reservoir is liquid-pumped by the high-load type cooling chamber. Can be sent to. Therefore, it is only necessary to operate the liquid pump only when the CO2 brine liquid is sent to the high load type cooling chamber, and the power of the liquid pump can be saved.

  In the present invention, the high load type cooling chamber is on a lower floor than the other cooling chambers, the CO2 liquid reservoir is disposed below each cooling chamber, and the CO2 brine liquid supply path is an air cooler of the storage type cooling chamber. It is preferable to branch from the forward path of the CO2 circulation path at the upstream side portion in the CO2 flow direction and to be connected to the forward path of the CO2 circulation path at the upstream portion in the CO2 flow direction of the air cooler of the high load type cooling chamber. As a result, the CO2 brine liquid cooled and liquefied by the heat storage effect of the storage-type cooling chamber naturally flows into the high-load cooling chamber by gravity, and the CO2 brine gasified in the high-load cooling chamber is the principle of the thermosiphon effect. Can be returned to the storage-type cooling chamber through the return path of the CO2 circulation path. Therefore, it is not necessary to operate the liquid pump, and the power of the liquid pump can be saved.

  According to the present invention, even in a refrigerated warehouse having a high load type cooling room and a storage type cooling room, such as a distribution type refrigerated warehouse, it is possible to achieve power saving and to operate the refrigerator at the time of daytime power peak. While stopping, the cooling chamber can be maintained at a set cooling temperature.

It is a whole block diagram of the refrigerator warehouse which concerns on one Embodiment of this invention method. It is a whole block diagram of the refrigerated warehouse which concerns on 1st Embodiment of the refrigerated warehouse of this invention. It is a block diagram of the control system of the refrigerated warehouse which concerns on the said 1st Embodiment. It is a whole block diagram of the refrigerator warehouse which concerns on 2nd Embodiment of the refrigerator warehouse of this invention.

  Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this embodiment are not intended to limit the scope of the present invention to that unless otherwise specified.

(Embodiment 1)
An embodiment of the method of the present invention will be described with reference to FIGS. In FIG. 1, a three-story refrigerated warehouse 10 is provided above the ground GL, and a semi-basement 12 is provided on the right side of the refrigerated warehouse 10. On each floor of the refrigerated warehouse 10, cooling chambers 14a, 14b, and 14c are provided in order from the first floor, and cargo handling chambers 16a, 16b, and 16c are provided on the left side of each cooling chamber. The cargo handling chambers 16 a to 16 c are provided with an elevator 18, and the cooled article 14 can be carried into and out of the cooling chamber 14 a or 14 b using the elevator 18.

  The loading / unloading doorway (dock) is provided in the cargo handling room 16a on the first floor, the rear part of the loading platform of the transport vehicle 22 is inserted into the loading / unloading doorway, and the cold-insulated product 24 is carried in and out. The handling chamber 16a is provided with a dock shelter 20 that covers the loading / unloading doorway. Air-conditioned air in the handling chamber 16a escapes to the outside, and outside air, rain wind, moisture, dust, pests, etc. enter the handling chamber 16a. This is prevented by the dock shelter 20.

  An ammonia refrigerator 26 is provided inside the semi-basement 12. A primary refrigerant circuit 28 in which NH 3 circulates, and a compressor 30, a condenser 32, an expansion valve 34, and an evaporator 36 provided in the primary refrigerant circuit 28 are configured. In addition, a CO 2 reservoir 38 is provided inside the semi-basement 12. A CO 2 circulation path 40 is provided between the CO 2 liquid reservoir 38 and the evaporator 36. The gaseous CO2 brine that has entered the evaporator 36 from the CO2 liquid reservoir 38 via the CO2 circulation path 40 is cooled by the evaporator 36 to become liquid and returns to the CO2 liquid reservoir 38. The CO2 reservoir 38 is provided with a pressure sensor 42 that detects the internal pressure. The detection value of the pressure sensor 42 is sent to the control device 60 described later.

  One or a plurality of air coolers 44a to 44c are provided in the cooling chambers 14a to 14c, respectively. The air coolers 44a to 44c and the CO2 reservoir 38 are connected by a CO2 circulation path 50 and branch paths 52a and 52b. The CO2 brine liquid is sent from the CO2 liquid reservoir 38 through the CO2 circulation path 50 and the branch paths 52a and 52b to the air coolers 44a to 44c. A liquid pump 51 is provided in the forward path 50 a of the CO 2 circulation path 50. When a plurality of cooling chambers are provided in each cooling chamber, each cooling chamber is arranged in parallel to the CO 2 circulation path 50.

  An opening / closing valve 54a is provided at the upstream side portion of the branch passage 52a with the air cooler 44a interposed therebetween, and an opening / closing valve 56a is provided at the downstream side portion. Further, an opening / closing valve 54b is provided at the upstream side portion of the branch passage 52b with the air cooler 44b interposed therebetween, and an opening / closing valve 56b is provided at the downstream side portion. Further, an open / close valve 54c is provided at an upstream portion of the CO2 circulation path 50 with the air cooler 44c interposed therebetween, and an open / close valve 56c is provided at a downstream portion.

  Each of the air coolers 44a to 44c is provided with fans 46a to 46c. The fans 46a to 46c form an air flow a inside the air coolers 44a to 44c, thereby improving the heat transfer efficiency between the CO2 brine solution and the room air. It can be improved. Temperature sensors 58a to 58c are provided in the cooling chambers 14a to 14c, respectively, and detection values of the temperature sensors 58a to 58c are sent to the control device 60 (see FIG. 2).

  FIG. 2 shows the control system of this embodiment. In FIG. 2, detection values of the pressure sensor 42 and the temperature sensors 58 a to 58 c are input to the control device 60. Based on these detection values, the control device 60 controls the operations of the drive device 30a of the compressor 30, the liquid pump 51, the drive devices 48a to 48c of the fans 46a to 46c, and the on-off valves 54a to 54c and 56a to 56c. . During normal operation, the on-off valves 54a-c and 56a-c are opened, the ammonia refrigerator 26, the liquid pump 51 and the fans 46a-c are operated, and the CO2 liquid reservoir 38 is changed from the CO2 liquid reservoir 38 to the air cooler 44a. To c to cool the cooling chamber.

  In such a configuration, the cooling chamber 14a provided on the first floor is a high-load type cooling chamber in which the cold article 24 is heavily loaded and unloaded and the cooling load in the daytime is large, and the cooling chambers 14b and 14c are relatively low in the cold article 24. It is a storage-type cooling room with little in and out. The CO2 temperature of the CO2 reservoir 38 is set to -32 ° C, and the pressure is set to 12.3 MPa. The normal set temperature of the cooling chambers 14a-c such as daytime is set to −25 ° C., and the refrigerator 26, the liquid pump 51, the fans 46a-c, etc. are operated so that the cooling chambers 14a-c become this temperature.

  In a time zone where the amount of power consumption is low, such as at night, the cooling chambers 14a to 14c are set to −28 ° C., which is a temperature lower than the set temperature and at which CO 2 can be liquefied under the pressure. Thus, the operation of the ammonia refrigerator 26 is controlled so that the cooling chambers 14a to 14c reach this temperature. When the CO2 pressure in the CO2 reservoir 38 exceeds the set value, the operation of the ammonia refrigerator 26 is controlled to cool the CO2 brine and liquefy it to reduce the CO2 pressure.

  The ammonia refrigerator 26 is stopped in a time zone in which daytime power consumption is at its peak. While the ammonia refrigerator 26 is stopped, the cooling load increases due to the insertion / extraction of the article 24 to be cooled in the cooling chamber 14a, and the indoor temperature of the cooling chamber 14a becomes higher than “−25 ° C. + ΔT (for example, 1 ° C.)”. Then, the fans 46a to 46c and the liquid pump 51 in the cooling chambers 14a to 14c are simultaneously operated. The cooling chambers 14b and 14c are cooled to −28 ° C. by nighttime operation, and the CO 2 liquid circulating in the air coolers 44b and 44c is cooled and liquefied by the cold air in the cooling chambers 14b and 14c.

  In the cooling chamber 14a, the CO2 brine liquid circulating through the air cooler 44a is in a gas-liquid mixed state in which the gas is partially evaporated. The CO2 brine liquid cooled by the cold air in the cooling chambers 14b and 14c and the CO2 brine in a gas-liquid mixed state that is partially evaporated and gasified by exchanging heat with room air in the cooling chamber 14a are the return path 50b and CO2 of the CO2 circulation path. The CO2 gas that has joined and mixed in the liquid reservoir 38 and partially evaporated in the cooling chamber 14a is liquefied. The liquefied CO2 brine is supplied to the air cooler 44a of the cooling chamber 14a through the CO2 circulation path 50 and the CO2 liquid reservoir 38. The cooling chamber 14a is cooled by this CO2 brine solution. As a result, the cooling chamber 14a can be returned to the normal set temperature of -25 ° C.

  Therefore, even when the ammonia refrigerator 26 is stopped, each cooling chamber can be maintained at −25 ° C., which is a normal set temperature, including the cooling chamber 14a in which the article to be cooled 24 is frequently taken in and out. As described above, the cooling chamber 14a is cooled using the heat storage effect of the storage-type refrigerated warehouses 14b and 14c with relatively little entry / exit of the product to be cooled 24, and at a set temperature that does not cause excessive cooling during nighttime operation. Since the ammonia refrigerator 26 is operated to a certain −28 ° C., power saving can be achieved.

(Embodiment 2)
Next, a first embodiment of the device of the present invention will be described with reference to FIG. In the present embodiment, in addition to the configuration of the above embodiment, one end is connected to the CO2 circulation path 50 between the on-off valve 54c and the air cooler 44c, and the other end is connected to the upper portion of the CO2 reservoir 38. A liquid supply path 62 is provided. Further, a CO2 brine supply path 64 is provided, one end of which is connected to the branch path 52b between the on-off valve 54b and the cooling chamber 14b, and the other end is connected to the CO2 brine liquid supply path 62. An open / close valve 66 c is provided in the CO 2 brine solution supply path 62, and an open / close valve 66 b is provided in the CO 2 brine solution supply path 64. The operation of the on-off valves 66b and 66c is controlled by the control device 60. Other configurations and operating conditions such as set temperature are the same as in the above embodiment.

  In this embodiment, when the ammonia refrigerator 26 is stopped at the daytime power peak and the cooling chamber 14a becomes higher than “−25 ° C. + ΔT (for example, 1 ° C.)”, the on-off valves 54b and 54c are closed, and the on-off valve 66b And other open / close valves including 66c are opened. And the fans 46a-c and the liquid pump 51 of the cooling chambers 14a-c are operated simultaneously. The cooling chambers 14b and 14c are cooled enough to liquefy the CO2 circulating through the air coolers 44b and 44c during nighttime operation. At this time, heat exchange with room air is performed by the air cooler 44a of the cooling chamber 14a, and the evaporated CO2 gas and the gaseous CO2 brine of the CO2 reservoir 38 naturally rise in the return path 50b of the CO2 circulation path 50. The air coolers 44b and 44c are cooled and liquefied.

  The CO2 brine liquefied by the air coolers 44 b and 44 c flows down through the CO2 brine liquid supply paths 62 and 64 by gravity and flows into the CO2 liquid reservoir 38. The CO2 brine liquid that has flowed into the CO2 liquid reservoir 38 is supplied to the air cooler 44a by the liquid pump 51 via the on-off valve 54a. The cooling chamber 14a is cooled by this CO2 brine solution, and the temperature of the cooling chamber 14a returns to the set temperature of −25 ° C.

  According to the present embodiment, in addition to the operational effects obtained by the embodiment shown in FIGS. 1 and 2, the liquid pump 51 may be operated only to send the CO2 brine liquid to the air cooler 44a. Therefore, the power of the liquid pump 51 can be saved.

(Embodiment 3)
Next, 2nd Embodiment of this invention apparatus is described based on FIG. In the present embodiment, a CO2 brine liquid supply path having one end connected to the CO2 circulation path 50 between the on-off valve 54c and the air cooler 44c and the other end connected to the branch path 52a between the on-off valve 54a and the air cooler 44a. 68 is provided. In the CO2 brine liquid supply path 68, an opening / closing valve 70 is provided near the air cooler 44c, and an opening / closing valve 72 is provided near the air cooler 44a. The opening / closing operation of the opening / closing valves 70 and 72 is controlled by the control device 60. Other configurations and operating conditions such as set temperature are the same as those of the embodiment shown in FIGS.

  In the present embodiment, the normal set temperature of the cooling chambers 14a to c such as daytime is set to −25 ° C., and the refrigerator 26, the liquid pump 51, the fans 46a to c and the like are set so that the cooling chambers 14a to 14c are at this temperature. To drive. And in the time zone when the amount of power consumption is small such as at night, the cooling chambers 14a to 14c are set to -28 ° C., which is a temperature lower than the set temperature and at which CO 2 can be liquefied under the pressure. The operation of the ammonia refrigerator 26 is controlled by the device 60 so that the cooling chambers 14a to 14c reach this temperature.

  When the daytime power peak, the ammonia refrigerator 26 is stopped, and when the cooling chamber 14a becomes higher than “−25 ° C. + ΔT (for example, 1 ° C.)”, the on-off valves 54a, 56b and 54c are closed, and the on-off valves 70 and 72 are turned on. Open other open / close valves including it. Then, the fans 46a and 46c of the cooling chambers 14a and 14c are operated. The cooling chamber 14c is sufficiently cooled to liquefy the CO2 circulating through the air cooler 44c by nighttime operation. At this time, the CO2 brine gasified by cooling the cooling chamber 14a flows into the air cooler 44c through the on-off valve 56a, the return path 50b, and the on-off valve 56c, and is cooled and liquefied by the air cooler 44c.

  The liquefied CO2 brine naturally flows down through the CO2 brine liquid supply path 68 by gravity and flows into the air cooler 44a. The CO2 brine gasified by heat exchange with room air in the cooling chamber 14a rises to the on-off valve 56a, the return path 50b, the on-off valve 56c, and the air cooler 44c on the principle of the thermosiphon effect. The gaseous CO2 brine that has reached the air cooler 44c is cooled again and liquefied by the air cooler 44c. The cooling chamber 14a is cooled by supplying the CO 2 brine solution to the air cooler 44a, and the temperature of the cooling chamber 14a returns to −25 ° C. which is the set temperature.

  According to the present embodiment, in addition to the effects obtained by the embodiments of FIGS. 1 and 2, the CO2 brine supplied to the air cooler 44 a is naturally circulated by the siphon principle, so that the liquid pump 51 is operated. It becomes unnecessary, and the electric power required for driving the liquid pump 51 can be reduced. In this embodiment, when the temperature of the cooling chamber 14a exceeds the set temperature, the CO2 brine liquid is supplied from only the air cooler 44c to the air cooler 44a. However, the air cooler 44c and the CO2 brine are used. A CO2 brine solution supply path that connects the liquid supply channel 68 may be provided, and the CO2 brine solution may also be supplied from the air cooler 44b.

  In addition, although all the said embodiments use the refrigerator which uses NH3 as a refrigerant | coolant, this invention can use the refrigerator using refrigerants other than NH3.

  According to the present invention, in a refrigerated warehouse having a plurality of cooling chambers including a high load type cooling chamber and a storage type cooling chamber, power saving is realized including a time zone in which power consumption is at a peak and other time zones. it can.

10 Refrigerated warehouse 12 Semi-basement 14a Cooling room (high load type cooling room)
14b, 14c Cooling chamber (storage type cooling chamber)
16a-c Loading room 18 Elevator 20 Dock shelter 22 Transport vehicle 24 Cooled product 26 Ammonia refrigerator 28 Primary refrigerant circuit 30 Compressor 30a Drive device 32 Condenser 34 Expansion valve 36 Evaporator 38 CO2 reservoir 40 CO2 circulation Path 42 pressure sensor 44a-c air cooler 46a-c fan 48a-c drive unit 50 CO2 circulation path 50a forward path 50b return path 51 liquid pump 52a, 52b branch path 54a-c, 56a-c, 66b, 66c, 70, 72 Open / close valve 58a-c Temperature sensor 60 Control device 62, 64, 68 CO2 brine liquid supply path GL Ground a Air flow

Claims (4)

In a power-saving operation method of a refrigerated warehouse having a plurality of cooling chambers including a high-load type cooling chamber with a large amount of cold storage / removal and a storage type cooling chamber with a small amount of cold storage / removal,
A first step of producing a CO2 brine solution with a refrigerator constituting a refrigeration cycle;
A second step of supplying the CO2 brine solution to an air cooler provided in each cooling chamber to cool each cooling chamber to a first set temperature;
A third step of operating the refrigerator in a time zone other than the time zone in which the power consumption reaches a peak, and cooling each cooling chamber to a second set temperature lower than the first set temperature and capable of liquefying CO2 brine. When,
Operation of the refrigerator is stopped during a time period including a time period in which the power consumption is at a peak, and the storage type cooling chamber is connected to the air cooler of the high load type cooling chamber that has become higher than the first set temperature. A power saving operation method for a refrigerated warehouse, comprising: a fourth step of supplying the CO2 brine liquid cooled and liquefied in step 4 and returning the temperature of the high load cooling chamber to the first set temperature. In a refrigerated warehouse having a plurality of cooling chambers including a high-load type cooling chamber with a large number of items to be taken in and out and a storage type cooling chamber with a few items to be taken in and out.
A refrigerator constituting a refrigeration cycle;
A CO2 liquid reservoir for storing the CO2 brine liquid cooled by the refrigerator;
An air cooler provided in each cooling chamber;
A CO2 circuit for supplying a CO2 brine solution from the CO2 reservoir to the air cooler;
A liquid pump provided in a forward path of the CO2 circulation path for supplying a CO2 brine liquid from the CO2 liquid reservoir to the air cooler;
A temperature sensor provided in each cooling chamber;
A refrigerated warehouse comprising a CO2 brine liquid supply path that branches from the CO2 circulation path and supplies the CO2 brine liquid cooled and liquefied in the storage-type cooling chamber to the high-load cooling chamber. The high-load cooling chamber is on a lower floor than the storage-type cooling chamber, and the CO2 liquid reservoir is disposed below each cooling chamber,
The CO2 brine supply path is branched from the forward path of the CO2 circulation path at the upstream side of the CO2 flow direction of the air cooler of the storage type cooling chamber, and is connected to the CO2 liquid reservoir. The refrigerated warehouse according to claim 2. The high-load cooling chamber is on a lower floor than the storage-type cooling chamber, and the CO2 liquid reservoir is disposed below each cooling chamber,
The CO2 brine liquid supply path branches from the forward path of the CO2 circulation path at the upstream side of the CO2 flow direction of the air cooler of the storage type cooling chamber, and upstream of the CO2 flow direction of the air cooler of the high load cooling chamber. 3. The refrigerated warehouse according to claim 2, wherein a side part is connected to an outward path of the CO2 circulation path.

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