JPH0552435A - Method for stored heat-utilizing cooling - Google Patents

Abstract

PURPOSE:To provide a cooling method which, in a plant where an apparatus for cooling and an apparatus for refrigeration are installed adjacently to each other, enables increasing the cooling efficiency of both apparatuses and lowering their running cost. CONSTITUTION:An apparatus for cooling of indoor air and an apparatus for refrigeration are installed adjacently to each other and also a heat storage part 3 which is capable of being charged with heat by both the two apparatuses is provided. The heat stored in the heat storage part 3 is used as cooling heat for the cooling apparatus and also as subcooling heat for the refrigerating apparatus 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat storage type cooling method which can be used in various facilities provided with a cooling device and a refrigerating device, such as a supermarket.

[0002]

2. Description of the Related Art Generally, in a supermarket or the like, as shown in FIG. 8, an air conditioner 2'having an air conditioning system.
And a refrigeration system 1'for showcases and the like are provided side by side. As a cooling system of the air conditioner 2'of such a facility, a so-called heat storage type cooling system considering energy saving has recently been widely used. There is.

An example of this heat storage type cooling system is shown in FIG. Reference numeral 21 is a compressor, 22 is a condenser, 23 is a liquid receiver, and 24 is a solenoid valve, and these constitute the condensing unit 20. Further, 25 is an expansion valve, 27 is a heat transfer tube, 3'is a heat storage tank, and water is filled in the heat storage tank 3 '. The system with this configuration has an air-cooled condensing unit 20,
The low-temperature, low-pressure refrigerant that has passed through the expansion valve 25 is evaporated in the heat transfer tube 27, and the heat of vaporization cools the water in the heat storage tank 3 ′ to make ice and store the heat, which is used as cooling heat when necessary. This system is used to perform cooling. Therefore, this system cools and ices the water in the heat storage tank 3'when the cooling load is low, such as at night, while only storing the cooling water when the cooling load is high, such as during the day. Can be used for cooling, and effective use of energy can be remarkably achieved. In addition, at night when the cooling load is low, the electricity charge is low, and since heat can be stored at that time, there is an advantage that the operation can be performed at low cost.

[0004]

As described above, the heat storage type cooling system can effectively use the energy and reduce the cost, but when it is used in the above-mentioned supermarket, etc. In the facility, the cooling load during the daytime is extremely high, and a large amount of heat storage is required for cooling. Therefore, the condensing unit 20 needs a certain amount of capacity to increase the heat storage amount. For this reason, how to suppress the capacity of the condensing unit 20 is one of the problems in an air conditioner 2'such as a supermarket where a heat storage type cooling system is used.

On the other hand, in spite of such a problem, the heat storage type cooling system is more significant than the compression type cooling system from the viewpoint of energy saving. In the refrigeration system 1'such as a supermarket, the cooling load is extremely reduced at night (because the inside of the showcase becomes empty). Therefore, if this heat storage type cooling system can be used, it is a very preferable configuration. However, in a refrigeration system 1'such as in a supermarket, the cooling load during the daytime increases extremely, so that it is difficult to directly adopt the heat storage type cooling system due to the limit of the cooling capacity. For this reason,
In the refrigeration system 1'of such a facility, the capacity of the condensing unit 10 has to be increased in consideration of the peak cooling load even though the operating rate at night when the cooling load is low is low. Even in such a refrigerating apparatus, it is an urgent issue to manage the effective use of energy and to keep the capacity of the condensing unit 10 small.

The present invention was devised in view of the above points of the prior art, and its purpose is to establish a facility such as a supermarket where the air conditioner (or the cooling device) and the refrigerating device are provided side by side. It is intended to provide a comprehensive cooling method that solves the above-mentioned two problems that occur at once.

[0007]

Therefore, in the cooling method according to the present invention, in a facility where a cooling device and a refrigerating device are provided side by side, a heat accumulating portion capable of accumulating heat in both the cooling device and the refrigerating device. Is provided, and the heat storage of the heat storage unit is used as the cooling heat of the cooling device and the supercooling heat of the refrigerating device.

The air conditioner naturally includes the air conditioner provided in the cooling system.

[0009]

Embodiments of the present invention will be described with reference to the drawings. The following examples show examples used in supermarkets.

FIG. 1 shows an example of an apparatus configuration for carrying out the heat storage type cooling method according to the present invention. In the figure, 1 is a refrigerating device, 2 is an air conditioner, and 3 is a heat storage tank.

The refrigeration system 1 includes a condensing unit 10 including a compressor 11, a condenser 12, and a liquid receiver 13, an electromagnetic valve 14 for limiting the flow rate of the refrigerant, and an expansion valve 15 for bringing the refrigerant into a low temperature / low pressure state. And heat transfer tubes 16, 17, 18 for heat exchange,
Refrigerant such as CFC circulates between them, and heat is finally exchanged in the heat transfer tube 16 in the showcase 5 for cooling by a circulation cycle of compression / condensation / expansion / evaporation of the refrigerant. is there.

In particular, in this embodiment, the heat storage tank 3 and the supercooler 4 are installed in the middle of this refrigerant circulation cycle.

In the heat storage tank 3, a heat transfer tube 17 of the refrigeration system 1 and a heat transfer tube 27 of the air conditioner 2 described later are disposed therein, and water is sprinkled in that state. The heat storage in the heat storage tank 3 is performed by cooling the water stretched by the heat exchange of the heat transfer tubes 17 and 27 arranged therein, and further by making ice. That is, in this embodiment, the cooling system of both the refrigeration system 1 and the air conditioner 2 described later is configured to store heat. Further, if ice is made in the heat storage tank 3 for a predetermined amount or more, blocking occurs (usually, the amount of water is 7
0%), and the heat transfer tubes 17 and 27 may be damaged. Therefore, since it is necessary to control the amount of ice making, the heat storage tank 3 has a water level gauge.
31 and thermo switch 32 are installed. That is, the water level gauge 31 calculates the water level when a predetermined amount of ice is made in consideration of the expansion amount, and controls to stop the operation when the water level is reached. As shown in 2, the temperature drops when it comes into contact with the ice 35, so the position where the ice 35 reaches when a predetermined amount of ice is made is measured and the switch 32 is installed at that position. Ice 35
When it comes into contact with, it is controlled to stop its operation.
Further, the control of ice making is also performed by controlling the refrigerant circulation flow rate by opening and closing the electromagnetic valve 14 of the refrigerator 1 and the electromagnetic valve 24 of the air conditioner 2 described later. Further, pipes 33, 34 for circulating cooling water from the heat storage tank 3 to the subcooler 4 and an air conditioning heat exchanger 26 described later extend. The pipes 33 and 34 are connected to the cooling heat transfer pipes 41 and 28 installed in the subcooler 4 and the air conditioning heat exchanger 26, respectively.

The subcooler 4 is a heat transfer tube of the refrigerator 1.
18 and a cooling heat transfer tube 41 in which the cooling water from the heat storage tank 3 circulates. The cooling water circulating in the cooling heat transfer tube 41 is used to transfer the refrigerant of the refrigerator 1 circulating from the condenser 12 to the heat transfer tube. The heat is exchanged and supercooled while passing through 18. Therefore, the refrigerant is heat-exchanged in the heat transfer tube 16 in the showcase 5 in a supercooled state, so that the cooling capacity is increased by the supercooling amount in the supercooler 4.

The air conditioner 2 has both heating and cooling systems, and the heat exchange thereof is performed by the air conditioning heat exchanger 26, of which the cooling system is a heat storage type cooling system. Ie, this is compressor 2
1, an air-cooled condensing unit 20 including a condenser 22, a liquid receiver 23, and a solenoid valve 24a, an expansion valve 25, and the heat storage tank 3
The heat transfer pipe 27 disposed inside the heat transfer pipe 27 evaporates the low temperature / low pressure refrigerant through the condensing unit 20 and the expansion valve 25 in the heat transfer pipe 27. Cooling and ice making are performed to store heat, and the cooling water is passed through the heat transfer pipe 28 of the air conditioning heat exchanger 26 through the pipe 33, while heat is taken from the outside air to perform cooling. In such a heat storage type cooling system, the capacity of the air-cooled condensing unit 20 is determined in consideration of the heat storage amount corresponding to the cooling load at the peak, but in the present embodiment, as described above, in the heat storage tank 3 Since the heat transfer pipe 17 of the refrigeration system 1 is also provided in the refrigeration system 1 and the heat storage capacity is distributed, the capacity of the condensing unit 20 on the air conditioning system 2 side can be reduced. On the other hand, the heating system in the present embodiment uses the water heated by the boiler 29 through the pipe 33 as in the case of cooling the air conditioning heat exchanger.
The 26 heat transfer tubes 28 are passed through, and heating is performed by heat exchange during the passage. It should be noted that electromagnetic valves 24b are respectively installed in the middle of the pipes 33 so that hot water does not flow into the heat storage tank 3 during heating.

Next, an operation example of the above-described embodiment will be described.

◎ Example of nighttime operation in the cooling period Since the cooling load is low at night, especially in a supermarket, and the midnight power is inexpensive, it is preferable to mainly operate the heat storage mainstream. An example of this operation will be described below with reference to FIG. First, the operation of the refrigeration system 1 is such that the refrigerant passing through the compressor 11 and the condenser 12 is passed through the expansion valve on the showcase side until the inside of the showcase 5 reaches a predetermined temperature.
15a, the heat is transferred to the heat transfer tube 16 and is circulated between them to cool the inside of the showcase 5 by heat exchange of the heat transfer tube 16 (indicated by a dotted line in the figure). The heat exchange in the heat transfer tube 16 is due to the heat of vaporization when the refrigerant evaporates. When the inside of the showcase 5 reaches a predetermined temperature, the electromagnetic valve 14a on the showcase side is closed and the refrigerant is circulated to the heat storage tank 3 side (indicated by a solid line in the figure). The refrigerant cools the water in the heat storage tank 3 by the heat of vaporization when it evaporates when passing through the expansion valve 15b on the heat storage tank side and the heat transfer tube 17, and further makes ice. On the other hand, air conditioner 2
On the side operation, the refrigerant is circulated through the compressor 21, the condenser 22, the expansion valve 25, and the heat transfer tube 27, and as in the above case, the heat of vaporization when the refrigerant evaporates in the heat transfer tube 27 is used to make ice in the heat storage tank 3. To perform. By the above operation, the amount of ice in the heat storage tank 3 increases, but when the amount of ice making reaches a predetermined amount, the water level gauge 31 or the thermoswitch 32 is activated and the operation is stopped.

◎ Example of Daytime Operation in Cooling Period In the daytime, the heat storage is used as the supercooling heat of the refrigeration system 1 and the cooling heat of the air conditioning system 2. An example of this operation will be described below with reference to FIG. The refrigeration system 1 side circulates the refrigerant to the showcase 5 side to cool the inside of the showcase 5, while the cold water from the heat storage tank 3 is circulated in the pipe 34 by the pump 36 to cool the subcooler 4. Pass through the heat transfer tube 41. Inside the other heat transfer tube 18 of the subcooler 4 is an expansion valve 15a.
Since the refrigerant flowing toward the cooling medium passes therethrough, the cooling medium exchanges heat with the cooling water. Therefore, this refrigerant is expanded in the expansion valve 15a in a supercooled state, so that the cooling efficiency is improved. On the side of the air conditioner 2, the cold water from the heat storage tank 3 is circulated to the heat exchanger 26 for air conditioning by the pump 37, and the cold water exchanges heat with the indoor air. At this time, the operation of the air-cooled condensing unit 20 is stopped.

◎ Example of operation during heating period In the heating period, the cooling of the air conditioner 2 is not necessary, so the operation of the condensing unit 20 is stopped both day and night. Heating is handled by hot water circulation by the boiler 29. On the other hand, the refrigeration system operates exactly the same as during the cooling period. That is, at night, the electromagnetic valve 15a is controlled to circulate the refrigerant to the heat storage tank 3 side to store heat, and during the daytime, the stored heat is used as supercooling heat to freeze the showcase 5.

From the above operation example, the following remarkable operational effects are recognized in this embodiment. In the present embodiment, the refrigeration system is caused to store heat at night when the conventional operating rate is low, and by using the stored heat as supercooling heat, balanced operation can be achieved by effectively utilizing the surplus capacity of the refrigeration system. It can be done. In particular, since the late-night power is cheap, the cost can be reduced by operating at midnight. In the refrigerating apparatus, the accumulated heat is used as supercooling heat, so that the cooling efficiency is improved and the capacity of the condensing unit can be reduced. On the other hand, in the air conditioner, the heat storage capacity in the heat storage tank is reduced by the distribution amount of the refrigerating device, and this can also reduce the capacity of the condensing unit. Further, as a whole, the heat storage is used as the cooling heat of the air conditioner and the supercooling heat of the refrigeration system, so that the heat storage can be effectively used, and the air conditioning system and the refrigeration system are provided separately. Compared with the configuration that is operated and operated, the efficiency and cost can be significantly reduced.

The present inventors examined whether or not these operational effects can be actually obtained especially in the refrigeration system. Next, the examination result will be described as a test example.

Under the following conditions, this embodiment shown in FIG.
The capacity and refrigerating capacity of the refrigerating apparatus were examined while comparing with the conventional example shown in FIG. Facility: Supermarket (sales floor area: 1100m ² , 1 floor above ground) Refrigeration system: 360 days / year, 24 hours operation Refrigerant Freon 22 air conditioner: Air-conditioning period (May-October) 180 days Heating period (11-March) ) 150 days 11 hours operation from 9:00 to 20:00 Heat storage tank: 23m ³

For each showcase, the required capacity of the refrigeration system was compared based on the rated output (Kw). The results are shown in Table 1.
Shown in. From the table, it can be seen that a total output of 103 Kw was required in the conventional example, but a device configuration of 78.6 Kw output is sufficient in the present embodiment.

[0024]

[Table 1]

Next, the freezing capacity was compared on the basis of enthalpy. FIG. 5 is a pressure-enthalpy diagram showing this result. In the figure, the curved line shows the state of freon [22], and the solid line forming the inverted trapezoid shows the conventional refrigeration cycle. In this example, when the refrigerant was supercooled, the refrigeration cycle changed as shown by the broken line. As the range of C in the figure increases, the cooling capacity increases accordingly (capacity efficiency: C /
B), it can be seen that the capacity of this embodiment is about 1.3 times higher than that of the conventional example.

Further, the present invention is not limited to the above embodiments, and various configurations, for example, the configuration examples shown in FIGS. 6 and 7 are conceivable. FIG. 6 shows that the cooling water in the heat storage tank 3 is used as a cooling system for the air conditioner 2.
The condensing unit 20 has a device configuration in which the refrigerant of the condensing unit 20 directly performs the cooling operation.
An air-conditioning heat exchanger 6 is provided so that the refrigerant from can be circulated. Further, FIG. 7 adopts a so-called heat pump system as a heating system of the air conditioner 2, and is basically the same as the configuration of the first embodiment except that the unit 7 for the heat pump is arranged.

[0027]

According to the cooling method of the present invention as described above, it is possible to improve the cooling efficiency while minimizing the capacities of the cooling device and the refrigerating device. Moreover, since the heat storage can be used more effectively, it can be sufficiently used as a device configuration for energy saving measures. Further, since the cooling efficiency as a whole is considerably improved, the cost can be reduced, and in addition, the inexpensive late-night power can be effectively used, so that the cost merit is greater.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an example of a device configuration for implementing a method of the present invention.

FIG. 2 is an explanatory diagram showing control of a thermoswitch.

FIG. 3 is an explanatory diagram showing an operation example at night during a cooling period in the embodiment of FIG.

FIG. 4 is an explanatory diagram showing an operation example during a daytime during a cooling period in the embodiment of FIG.

5 is a pressure-enthalpy diagram showing the refrigerating capacity of the present embodiment of FIG.

FIG. 6 is an explanatory diagram showing another example of the apparatus configuration for carrying out the method of the present invention.

FIG. 7 is an explanatory diagram showing another example of a device configuration for carrying out the method of the present invention.

FIG. 8 is an explanatory diagram showing an air conditioner and a refrigerating device in a conventional facility such as a supermarket.

FIG. 9 is an explanatory diagram showing an example of a heat storage type cooling system.

[Explanation of symbols]

 1, 1'Refrigerator 2, 2'Air conditioner 3, 3'Heat storage tank 4 Supercooler 5 Showcase

Claims (1)

[Claims] 1. In a facility where a cooling device and a refrigerating device are provided together, a heat storage part capable of storing heat by both the cooling device and the refrigerating device is provided, and the heat stored in the heat storage part is cooled by the cooling device. A heat storage utilization type cooling method, which is used as heat and used as supercooling heat of the refrigeration system.