JP2000240990A - Ice heat storage system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an ice heat storage system adaptable to environmental improvement of convenience store, or the like, by conducting air conditioning in correspondence with an air conditioning load while accumulating heat when an air conditioning load, e.g. cooling or heating, is required in night time. SOLUTION: In ice heat storage system comprising a circulation circuit formed by coupling a heat source machine (heat pump) D and a heat storage water tank 20 through refrigerant piping, the heat storage water tank 20 is coupled to the air conditioning load C side through a lower water supply pipe 15 and an upper return pipe 15'. The lower water supply pipe 15 is provided with a three-way mixing valve 16 and a circulation pump 17 and the upper return pipe 15' is provided with a follow-up heat exchanger 13 and piping for branching a part of water delivered from the heat exchanger 13 to the three-way mixing valve 16. Piping for circulating a part of refrigerant to the follow-up heat exchanger 13 is branched from the way of refrigerant piping (a) on the low pressure side of the ice heat storage system and refrigeration flow regulation valves 12B, 12A are provided, respectively, for the refrigerant branch piping and the branched refrigerant piping of the ice heat storage system.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ice heat storage system, and more particularly to a small ice heat storage system device capable of coping with relatively light air-conditioning loads even at night.

[0002]

2. Description of the Related Art In a conventional air conditioner, in the case of a non-heat storage type air conditioner, there is no problem even if there is an air conditioning (cooling or heating) load at night. The operation until 8:00 is a time for heat storage, during which the operation is performed exclusively for heat storage without air conditioning.

[0003] This is not a problem if the air conditioning load is not required at night. However, for example, in a convenience store that is open 24 hours, the temperature still drops on summer nights, but the heat still remains. It is often necessary to continue. Certain types of small ice storage systems make ice at night, use the ice to cool the refrigerant liquid during refrigerant operation, increase the degree of supercooling, and increase the operating efficiency, thereby cooling the ice produced at night. However, since a large cooling capacity can be obtained with a small amount of operation, there is an effect of reducing the power consumption in the daytime, which contributes to the level of the power load. However, with this type of cooling, it is impossible to cool at the same time as ice making, even if ice can be made at night.

[0004]

SUMMARY OF THE INVENTION The present invention addresses the above-described situation, and in particular, not only when storing heat at night, but also when the need for air-conditioning load such as cooling and heating is required at night, it is possible to perform air-conditioning while storing heat. It is an object of the present invention to find a control means to perform the heat storage at night even while storing heat at night, thereby making it possible to perform air conditioning by adapting to a relatively light air conditioning load, and to adapt to environmental improvements such as convenience stores.

[0005]

That is, the feature of the ice heat storage system of the present invention that meets the above-mentioned object is that a heat exchanger, a circulator pump, and the flow rate of a refrigerant are controlled by following a conventional ice heat storage system. A refrigerant flow control valve for switching the flow of air is added, and the mixing three-way valve on the water side is made to function even at night when there is a request signal for air conditioning, thereby enabling air conditioning. Heat exchangers, receivers,
In an ice heat storage system in which an accumulator and a heat storage water tank are formed in a circulation circuit by a refrigerant pipe, the heat storage water tank and the air conditioning load side are connected by a lower water supply pipe and an upper return pipe, and a mixing three-way valve and a circulation pump are respectively connected to the lower water supply pipe. A heat exchanger that follows the upper return pipe and a branch pipe that diverts a part of the water exiting the heat exchanger to the mixing three-way valve are provided, respectively, while a low pressure side of the ice heat storage system is provided. In the middle of the refrigerant pipe, a refrigerant branch pipe that branches from the pipe and circulates a part of the refrigerant to the follow-up heat exchanger is provided, and the refrigerant branch pipe and the refrigerant pipe of the ice storage system after branching are provided with refrigerant respectively. It is characterized by a configuration in which a flow control valve is provided.

[0006]

The ice heat storage system having the above configuration has no air conditioning load and can be used in the same way as the original ice heat storage system when dedicated to ice making, and it is necessary to branch and flow the refrigerant into the follow-up heat exchanger. There is no. When both night-time air conditioning and heat storage are used, both refrigerant flow control valves are opened, the load heat is directly cooled by the follow-up heat exchanger, and low-pressure refrigerant flows through the coil of the heat storage water tank to cool the water in the water tank while making ice. Prepare for.

On the other hand, the three-way mixing valve operates to supply water to the air-conditioning load at a constant water temperature to perform cooling. (First half of night air-conditioning operation) Also, when the flow of refrigerant to the follow-up heat exchanger is shut off, the entire low-pressure refrigerant flows only from the refrigerant flow control valve of the ice heat storage system to the heat storage water tank coil, and the water temperature in the water tank decreases. When the temperature is close to 0 ° C. and ice making is in progress (the latter half of the night air-conditioning operation), the mixing valve functions to supply water to the load at a constant water temperature.

Next, in the cooling operation in the daytime, when the heat pump of the ice heat storage system is operated, and the low-pressure refrigerant flows through the additional heat exchanger only through the refrigerant flow control valve to the additional heat exchanger, the additional heat exchanger is activated. The load water is cooled directly by the heat exchanger. At this time, the ice accumulated in the water tank is melted, the rise in water temperature is suppressed, and the mixing valve functions to supply water at a constant water temperature to the load. Further, when the heat pump is stopped and the flow of the refrigerant stops, the ice accumulated in the water tank is melted to suppress the rise in water temperature, and the mixing valve functions to supply the load at a constant water temperature. This operation is a cooling operation that does not use electric power in summer. As described above, the device of the present invention has various modes of operation, and is operated according to each of the modes.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows a basic mode of an ice heat storage system according to the present invention in a state in which only the nighttime heat storage operation is performed and there is no air conditioning load, and only ice making is performed. In the figure, A indicates the outdoor side, B indicates the heat storage unit, C indicates the indoor load unit, and the outdoor side A indicates the refrigeration circuit heat pump D which is mainly a heat source unit.
An ice thickness sensor for protecting the heat storage water tank 20 in the middle thereof in a zigzag manner at the intermediate portion of the refrigerant pipe a in the heat storage water tank 20 of the heat storage part B. Reference numeral 22 denotes a load operation and a relief valve 21 are provided above the heat storage water tank 20, respectively.

As shown in the drawing, a heat pump D serving as a heat source unit includes a compressor 1, a four-way valve 2, an air heat exchanger 3, a second expansion valve 4, a solenoid valve 5, a receiver 6, a solenoid valve 7, and a first expansion valve. 10
And a refrigerant pipe system including a propeller fan 9 and a bypass having an electromagnetic valve 8 bypassing the refrigerant pipe, and a refrigerant pipe system including an accumulator 14 formed by switching the four-way valve 2. The circuit is configured.

The heat storage water tank 20 and the fan coils 31 and 32 of the air conditioning load section C are connected by a lower water supply pipe 15 and an upper return pipe 15 '. A three-way valve 16 and a circulation pump 17 for supplying water to the indoor fan coils 31 and 32 are sequentially provided.

On the other hand, on the side of the upper return pipe 15 ', a follow-up heat exchanger 13 and a branch pipe for diverting a part of water exiting the heat exchanger 13 to the mixing three-way valve 16 are provided. At the same time, a refrigerant pipe branched from the middle of the low-pressure side refrigerant pipe in the heat pump circuit of the ice heat storage system is provided in the follow-up heat exchanger 13 so that at least a part of the refrigerant can be circulated. And in this case, the heat storage water tank 2
Flow rate of the refrigerant flowing to the 0 side JP-A Sho, flow control valves 12A and 12B for appropriately adjusting the flow rate of the refrigerant flowing to the follow-up heat exchanger 13 or switching the flow of the refrigerant are provided, respectively.
Each flow rate can be adjusted. In the figure, 19
Is a gantry, 11A, 11B, 11C, 11D and 11E are thermistors, and 23 is a water level sensor.

In the above configuration, the mixing three-way valve 16 in the water supply pipe is transmitted to the control panel 18 on the outside A as an air conditioning request signal through an operation monitoring signal of the control units 33 and 34 provided inside the fan coil. It operates in response to cooling and heating loads while storing heat.

Hereinafter, examples of operation modes of the apparatus of the present invention will be described with reference to the drawings.

FIG. 1 described as the above basic circuit is a case of nighttime heat storage operation in which there is no cooling load and is dedicated to ice making. A solid line indicates a refrigerant pipe, a dotted line indicates a water pipe, and a solid line indicates a refrigerant flow. In this case, the solid thin line indicates the refrigerant flow passage, but indicates that the refrigerant is not used. The thick dotted line indicates the case where the pipe is used for water piping, and the thin dotted line indicates the case where it is not used. These are the same in FIG. Although not particularly described, each valve is closed at an unused portion.

In the case of FIG. 1, the refrigerant advances in the direction of the arrow only in the heat pump refrigeration circuit, the refrigerant pipe to the follow-up heat exchanger 13 is closed, and the water pipe is in an unused state.
Thus, it is clear that he is dedicated to ice making.

FIGS. 2 and 3 show an operation in which cooling and heat storage are used at night. FIG. 2 shows that the flow control valves 12A and 12B for switching the flow of the refrigerant are both opened, and the load heat is directly cooled by the follow-up heat exchanger 13, and the heat storage water tank 20 from the flow control valve 12A is also connected. In this state, a part of the refrigerant flows through the pipe, and the ice making is prepared while cooling the water in the water tank 20. In this case, the mixing three-way valve 16 functions, and the follow-up heat exchanger 13 exhibits the role of an evaporator. The constant water temperature is usually 5 to 7 ° C in summer and 40 to 45 ° C in winter. Supply water to bring out the cooling condition.

On the other hand, FIG. 3 shows a refrigerant control valve 1 as shown by an arrow in FIG.
The low-pressure refrigerant flows from 2A to the piping coil of the heat storage water tank 20,
The flow of the refrigerant to the follow-up heat exchanger 13 is shut off. In this case, the water temperature in the heat storage water tank 20 decreases to near 0 ° C., as the ice making progresses, the water pipe between the load side is open, and the mixing three-way valve 16 functions to return high-temperature return water and low-temperature water. The water from the heat storage water tank 20 is mixed and supplied to the load while maintaining one water temperature as described above.

Next, FIG. 4 shows that the heat pump of the refrigeration system is operated and the load water is directly cooled by the follow-up heat exchanger 13 from the refrigerant control valve 12B. On the other hand, since the refrigerant control valve 12A is closed and the flow of the refrigerant to the heat storage water tank 20 is shut off, the ice accumulated in the heat storage water tank 20 is melted. However, an increase in the water temperature is suppressed by the thermistor 11C. At this time, the mixing three-way valve 16 functions, and the heat storage water tank 2
Water from 0 and water cooled by the follow-up heat exchanger 13 are mixed, and water is supplied to the load at a constant water temperature in the same manner as described above to perform a cooling operation. This is an aspect during the daytime cooling operation.

FIG. 5 shows a state in which the heat pump is stopped as shown by the arrow in FIG. In this case, the ice stored in the heat storage water tank 20 is melted, and the rise in water temperature is suppressed. And the mixing three-way valve 16 functions,
The load water flows through the water pipe, and the water from the heat storage water tank 20 and the water on the return side of the load water are mixed and similarly supplied to the load at a constant water temperature. This operation is a peak cut operation if cooling is performed at 13:00 to 16:00 in the summer as an operation using no electricity using ice. This is the most common mode of operation during the interim period.

As described above, the system apparatus of the present invention can easily perform various operations by adjusting the cooling flow rate or switching the flow of the refrigerant, and always operates on the load side in cooperation with the mixing three-way valve and the follow-up heat exchanger. It can supply water with a constant water temperature. Therefore, it is possible to cope with nighttime air-conditioning load while using the ice heat storage system.

Next, a description will be given of an operation mode particularly in the summer season as follows. (1) While making ice, a part of the refrigerant is guided to a follow-up heat exchanger for air conditioning. (Case of FIG. 2) At this time, the amount of refrigerant flowing to the ice making decreases. (2) Utilize the cold water in the heat storage tank while making ice and use it for air conditioning load. (Fig. 3) In this case, the refrigerant flows to the heat storage tank, the warmed cold water returned from the air conditioning load returns to the heat storage tank, and the ice inside the water tank melts, so that the cold water is kept constant via the mixing three-way valve. The valve opening is adjusted so that it can be supplied at a temperature, and ice is used. On the other hand, ice making is in progress.

(3) Air conditioning is performed while using the above two items together. In each case. In addition, since the minimum ice making and cold storage are required for cooling the next day, if the amount of ice making is small at a certain time during the night, control is given to increase the supply water temperature by 1 ° C. by giving priority to cold storage. In the case of (1) above,
In the case of the above (2) in which the refrigerant flows in the total amount heat storage tank, the same control is performed in any case.

Further, in the case of the above (1), the evaporation temperature of the refrigerant becomes close to the evaporation temperature during air conditioning. The higher the refrigerant temperature, the lower the ice making capacity. Therefore, at midnight (22:00 to 24:00), which is the first half of the night time zone, the outside air temperature is still high, the air conditioning load is large, and the water temperature in the water tank is also high (10 to 24:00).
3 ° C.), which is suitable for this case. In this case, the mixing three-way valve may be turned off with respect to the heat storage tank in order to surely make ice.

In the case of the above (2), the whole amount turns to ice making, the refrigerant evaporating temperature becomes suitable for ice making, becomes lower than the evaporating temperature at the time of air conditioning, and the efficiency is slightly lowered, but it is unavoidable. Early morning in the latter half of the night time zone (3:00 to 6:
00) is suitable for this case, since the outside air temperature becomes minimum and the air-conditioning load also decreases.

In the case of (3), considering the above, it is understood that the efficiency is good if the first half of the cold storage time zone is operated by the method of (1) and the second half is operated by the method of (2).

[0028]

According to the present invention, as described above, the ice heat storage device is provided with the follow-up heat exchanger, the circulation pump, and the flow rate control valve for adjusting or switching the flow rate of the refrigerant. To provide a mixing three-way valve,
By forming various usage modes such as guiding a part of the refrigerant to the follow-up heat exchanger or directing the entire amount of the refrigerant to the heat storage water tank, the ice heat storage device can not only store heat at night, but also perform cooling and heating loads at night. When necessary, air conditioning can be performed while storing heat.Conventionally, an ice heat storage system, which used to store heat only at night, can be used as cooling and heating at night in combination with heat storage. Have.

[Brief description of the drawings]

FIG. 1 is a system diagram showing an aspect of a nighttime heat storage operation together with a basic circuit according to the present invention.

FIG. 2 is a system diagram showing one mode of an operation in which night-time cooling and heat storage are both used by using the circuit.

FIG. 3 is a system diagram showing another mode of operation using both the night cooling and the heat storage by using the above circuit.

FIG. 4 shows a daytime cooling operation using the system of the present invention.
It is a system diagram showing an aspect (heat pump operation).

FIG. 5 is a system diagram showing another mode (heat pump stop) of daytime cooling operation using the system of the present invention.

[Explanation of symbols]

 A Outdoor side B Heat storage side C Indoor side load part D Heat source unit (heat pump) 1 Compressor 2 Four-way valve 3 Air heat exchanger 4 Second expansion valve 5 Solenoid valve 6 Receiver 7 Solenoid valve 8 Solenoid valve 9 Propeller fan 10 First Expansion valve 11A to 11E Thermistor 12A to 12B Flow control valve 13 Tracking heat exchanger 14 Accumulator 15 Water supply pipe 16 Mixing three-way valve 17 Circulation pump 20 Heat storage water tank

Claims (1)

[Claims] 1. An ice heat storage system in which a compressor, a four-way valve, an air heat exchanger, a receiver, an accumulator, and a heat storage water tank are formed in a circulation circuit by a refrigerant pipe, a heat storage water tank, an air conditioning load side, and a lower water supply pipe and an upper part. Connected by a return pipe, a mixing three-way valve and a circulation pump are interposed in the lower water supply pipe, respectively, a follow-up heat exchanger in the upper return pipe, and a part of water exiting the heat exchanger is supplied to the mixing three-way valve. While arranging branch pipes to be diverted respectively, in the middle of the low-temperature side refrigerant pipe of the ice heat storage system, a refrigerant branch pipe that branches from the pipe and circulates a part of the refrigerant to the follow-up heat exchanger is provided, An ice heat storage system device, wherein a refrigerant flow control valve is interposed in each of the refrigerant branch pipe and the refrigerant pipe of the ice heat storage system after branching.