JP2001330280A - Ice thermal storage unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve problems of a decrease in an efficiency of a heat pump cycle due to a drop of a temperature of a low-pressure refrigerant as a growth of a generated ice in the case of using a flooded evaporator like a prior art in an ice thermal storage unit utilizing a heat pump and the like, and reductions in stability and durability of an ice thermal storage unit in the case of a closure of a channel due to a frequent phase change of water of a supercooling state to an ice in a heat exchanger, though an efficiency is improved in a method for ice thermal storing by generating the water of the supercooling state by using a plate type heat exchanger. SOLUTION: When a laminate type heat exchanger 5 formed by sequentially laminating a refrigerant plate 15 formed with a slit-like hole, a water plate 17 and a partition wall plate 16 inserted between these plates 15 and 17 is used, a flow of a water channel can be made in a laminar flow. Accordingly, the water of the supercooling state not frozen even at a temperature of an ice point or lower can be stably generated. Therefore, an icemaking (ice thermal storage) operation of a stable and high efficiency can be conducted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for storing ice heat using a phase change of water.

[0002]

2. Description of the Related Art Conventionally, an ice storage type air conditioner in which ice or cold water is generated by using surplus power at midnight, which is inexpensive, and cooling is performed by using ice or cold water generated in the daytime, Alternatively, a water storage type air conditioner has been proposed. When air conditioning is performed by this device, not only can the peak power demand be shifted, but also the running cost can be significantly reduced.

[0003] For example, as shown in FIG.
No. 931 discloses an apparatus in which a heat exchanger for evaporating a refrigerant to make ice is a liquid-filled evaporator formed in a coil shape or a U shape inside an ice heat storage tank. An external ice making type ice heat storage device for making ice by freezing water in contact with the surface portion of the ice.

[0004] Further, as shown in FIG.
The device described in Japanese Patent No. 5625 is a chilled water heat storage device that cools water by using a plate heat exchanger and stores chilled water in a chilled water heat storage tank.

[0005] Further, as shown in FIG.
The apparatus described in Japanese Patent Publication No. 517 uses a plate heat exchanger to cool water to a supercooled state, which is a liquid phase even at a temperature below the freezing point, and then impacts the supercooled water to produce ice. It is an ice thermal storage device.

FIG. 7 schematically shows a conventional ice heat storage device for making ice on the surface of a heat exchanger. In the heat pump circuit, which is connected by the refrigerant circuit 8 in the order of the compressor 1, the condenser 2, the decompression means 3a, and the ice making heat exchanger 4a in which a pipe is formed in a U-shape in the ice heat storage tank 9, the compressor 1 The condensed refrigerant is liquefied in the condenser 2,
After passing through a, low temperature and low pressure are applied, and the water 9a in contact with the surface of the ice making heat exchanger 4a which is a liquid-filled evaporator of the ice heat storage tank 9 is cooled and frozen. Therefore, ice 9b is generated on the surface of the ice making heat exchanger 4a, and the thickness of the generated ice 9b increases as the operation time elapses. The refrigerant that has passed through the ice making heat exchanger 4a is returned to the compressor 1 by the three-way valves 7a and 7b so as not to pass through the evaporator 6. The above-mentioned ice making (ice heat storage) operation is performed using surplus power at midnight. In the daytime, the following operation is performed. The high-pressure refrigerant liquefied in the condenser 2 passes through the depressurizing means 3a set so as to minimize the decompression width, enters the ice making heat exchanger 4a as a high-pressure liquid, and the high-pressure refrigerant is supplied to the ice making heat exchanger 4a. Cooled by the ice 9b formed on the surface, the ice 9b melts. The cooled refrigerant is sent to the evaporator 6 via the three-way valves 7a and 7b and the decompression means 3b. The evaporator 6 removes heat of vaporization from the outside and returns to the compressor 1. That is, the cold stored in the ice 9b is used to cool the high-pressure refrigerant, and the purpose is to improve the refrigerating effect and to greatly improve the efficiency of the daytime heat pump cycle. When using the device shown in FIG. 7 as an air conditioner,
The evaporator 6 is an indoor unit.

Further, as shown in FIG. 10, water 9a having a low temperature in the ice heat storage tank 9 can be sent directly to the evaporator 6 to absorb external heat.

The above-mentioned ice heat storage device accumulates ice in the ice heat storage tank 9 by the above-mentioned operation using electric power at midnight, and performs cooling using the ice accumulated in the daytime. Therefore, as the amount of ice that can be stored is larger, the peak shift rate of the power demand is higher, and the running cost can be reduced.

Further, the condenser 2 may be of a water-cooled type, and the hot water generated during the ice making operation may be used for hot water supply. Further, when the refrigerant of the heat pump circuit has a reverse flow such that the refrigerant circulates in the order of the compressor 1, the ice making heat exchanger 4a, the pressure reducing valve 3a, and the condenser 2, the water in the ice heat storage tank Is heated by the ice making heat exchanger 4a, and hot water is stored. The hot water stored in the ice heat storage tank can be used for heating.

[0010]

However, if ice heat storage is performed by an external ice making method in which ice is made on the surface of the ice making heat exchanger 4a by using a heat pump cycle as in the conventional method, the surface of the ice making heat exchanger 4a will be rejected. Since the temperature at which the refrigerant evaporates decreases with the growth of the ice 9b formed in the ice, the efficiency of the heat pump cycle decreases, and the running time for storing ice heat increases, so that the running cost increases. The heat transfer relating to the ice making heat exchanger 4a is as follows.
Since the heat conduction of the ice 9b is mainly performed, the heat pump cycle is easily affected by the thickness of the generated ice 9b and the form of the ice 9b at the time of melting, and it is difficult to promote heat transfer.

The method of producing ice by generating supercooled water using a plate heat exchanger or a double tube heat exchanger can perform an ice making (ice heat storage) operation without being affected by the ice that has been made. High efficiency of the system and low running cost can be realized. However, supercooled water undergoes a phase change to ice when subjected to a slight shock, and tends to change with a very slight impact as the supercooled temperature is lower. When water drift or turbulence occurs in the tubular heat exchanger, the supercooled water changes its phase to ice and blocks the flow path. In addition, since the temperature of the water flowing near the heat transfer surface is lower than the temperature of the mainstream water, even if the mainstream water is at a temperature higher than the freezing point, the water near the heat transfer surface may be supercooled. And the phase easily changes to ice in the water flow path of the heat exchanger. Frequently, if the ice blocks the flow path, the operation must be stopped, thus reducing the stability and durability of the device. Further, a heating device and a control device for melting the frozen ice are required, which increases the cost of the device.

An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide an apparatus capable of performing high-efficiency and stable ice heat storage operation.

[0013]

According to the present invention, there is provided a heat pump circuit in which a compressor, a condenser, a decompression means, and an ice making heat exchanger are sequentially connected by a refrigerant circuit, and an ice for storing water. A heat storage tank and a water circuit that exchanges heat of water in an ice heat storage tank with a refrigerant in a heat pump circuit in an ice making heat exchanger to cool to a supercooled state and then returns to an ice heat storage tank, and the ice making heat exchanger is a stacked type. An ice heat storage device characterized by being a heat exchanger.

According to the present invention, a high-efficiency and stable ice heat storage operation can be performed.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention can realize an ice heat storage device according to an embodiment which achieves the object of the present invention by adopting the structure described in each claim.

That is, as described in claim 1, a heat pump circuit in which a compressor, a condenser, a pressure reducing means, and an ice making heat exchanger are sequentially connected by a refrigerant circuit, an ice heat storage tank for storing water, and an ice heat storage tank A water circuit that exchanges heat with the refrigerant in a heat pump circuit in an ice making heat exchanger to cool the water to a supercooled state, and then returns the water to an ice heat storage tank, wherein the ice making heat exchanger is a stacked heat exchanger. By using the apparatus, the temperature of the low pressure refrigerant becomes independent of the amount of accumulated ice, and the efficiency during ice making (ice heat storage) operation can be maintained in a high state.

According to a second aspect of the present invention, there is provided a laminated heat exchanger comprising: a plurality of refrigerant plates having slit-shaped holes; a plurality of water plates having slit-shaped holes; The ice heat storage device according to claim 1, wherein the refrigerant flow path and the water flow path are formed from a plurality of partition plates provided between the water plates and forming a partition wall between the refrigerant and the water. Since the flow is laminar, the generated supercooled water can be sent to the ice storage tank without phase change to ice.

According to a third aspect of the present invention, a pre-cooling heat exchanger for cooling the water in the ice heat storage tank by exchanging heat with the refrigerant in the heat pump circuit is provided at the inlet of the water circuit of the stacked heat exchanger. By using the ice heat storage device according to item 1, the heat transfer area can be increased with the existing heat exchanger.

Further, a refrigerant circuit for connecting the pre-cooling heat exchanger and the stacked heat exchanger in order is provided, and the refrigerant circuit between the pre-cooling heat exchanger and the stacked heat exchanger is decompressed. The temperature of the low-pressure refrigerant can be controlled to an appropriate temperature by using the ice heat storage device according to the third aspect including the means.

[0020]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 schematically shows an ice heat storage device according to Embodiment 1 of the present invention. The ice heat storage device of FIG. 1 is a heat pump including a compressor 1, a condenser 2, a pressure reducing means 3a, a laminated heat exchanger 5, which is an ice making heat exchanger, and a refrigerant circuit 8 which sequentially connects three-way valves 7a, 7b. The refrigerant is decompressed by the circuit and the three-way valves 7a and 7b.
b, a heat pump circuit for passing the evaporator 6 in this order, a circulation pump 10 for circulating the water 9a stored in the ice heat storage tank 9 through the laminated heat exchanger 5, and a water circuit 11 for circulating the water. Have been. The temperature sensor 12 detects the temperature of the water flowing out of the stacked heat exchanger 5, and the control unit 13 controls the amount of water sent from the circulation pump 10 so that the temperature detected by the temperature sensor 12 becomes a predetermined temperature T1. It is for.

FIG. 2 is an exploded perspective view of the laminated heat exchanger 5. The laminated heat exchanger 5 is formed by sequentially laminating a refrigerant plate 15, a water plate 17, and a partition plate 16 inserted between these plates 15, 17. The refrigerant plate 15 has a refrigerant passage slit 15a which is a slit-shaped hole.
And a water passage slit 15b. The water plate 17 has a coolant passage slit 17 which is a slit-shaped hole.
a, a water passage slit 17b is formed. The partition plate 16 is provided with a refrigerant passage slit 1 which is a slit-shaped hole.
6a and a water passage slit 16b are formed. The coolant channel slit 15a forms a coolant channel by being sandwiched between the top plate 14, the partition plate 16 or the partition plates 16 on both surfaces. Water channel slit 17
a forms a water channel by being sandwiched between the partition plates 16 on both sides. Water passage slit 15b of refrigerant plate 15 and refrigerant passage slit 1 of partition plate 16
6a, the water passage slit 16b, and the refrigerant passage slit 17a of the water plate 17 are sequentially laminated to form a penetrating space, and the inflow passages 19a, 20a for sending the refrigerant and water to the flow path of each plate, Outflow passages 19b and 20b are provided for merging the refrigerant or water that has exchanged heat in each flow path and flowing out of the laminated heat exchanger 5. The top plate 14 is arranged on the uppermost surface of the stacked plates, and the end plate 18 is arranged on the lowermost surface, and each slit is used as a closed space.

The height of the refrigerant flow path of the laminated heat exchanger 5 and the flow path height of the water flow path are the thicknesses of the refrigerant plate 15 and the water plate 17, and the width of the flow path is the refrigerant flow path. The width of the slit 15a is equal to the width of the water passage slit 17a.
In this embodiment, the thickness of the water plate 17 is set to 0.1 to 2.0.
The thickness of the plate 17, the width of the slit 17a, and the number of plates to be laminated were designed so that the flow rate of water in the water flow path was laminar (Reynolds number was 1000 or less). The flow of the water flowing through the water flow path is laminar, and generally, the heat transfer of the laminar flow is low. However, when the flow path height is in the range of 0.1 to 2.0 mm as in the present invention, the temperature is low. The boundary layer is thinned. Therefore, when heat exchange occurs between the refrigerant flowing through the refrigerant flow passage and water, the temperature of the main flow flowing through the water flow passage and the temperature of the water flowing along the wall surface are substantially the same.

The operation and operation of this configuration will be described below. The refrigerant, which has become a high-temperature and high-pressure gas by the operation of the compressor 1, is decompressed when passing through the decompression means 3a after being liquefied in the condenser 2 and becomes a low-temperature low-pressure two-phase gas-liquid two-phase heat exchanger 5. Flows to The refrigerant cools the water circulated by the circulation pump 10 when flowing through the laminated heat exchanger 5, returns to the compressor 2, becomes high-temperature and high-pressure again, and is sent to the condenser 3. The water cooled by the stacked heat exchanger 5 returns to the ice heat storage tank, and the temperature at that time is detected by the temperature sensor 12, and the flow rate of the circulation pump 10 is controlled by the control unit 13 so as to reach a predetermined temperature. . The temperature of the water 9a stored in the ice heat storage tank 9 gradually decreases by the above operation. Here, the temperature of the water flowing out of the stacked heat exchanger 5 is set to a temperature below the freezing point, and the circulating pump is set so that the temperature detected by the temperature sensor 12 by the control unit 13 becomes the temperature below the set freezing point. At 10 the flow rate of the water sent is controlled. When the water flowing through the water flow path is cooled to a temperature below freezing, the water is in a supercooled state, which is a liquid phase even at temperatures below freezing. The phase changes and the water flow path is closed. However, as described above, the flow of the water cooled by the stacked heat exchanger 5 is laminar, and the temperature of the main flow flowing through the water flow passage and the temperature of the water flowing along the wall surface are substantially the same. For,
The supercooled water can pass through the flow path without phase change to ice. The supercooled water is discharged into the ice heat storage tank 9 after flowing out of the stacked heat exchanger 5, and is mixed with the water 9a in the ice heat storage tank 9. The supercooled water undergoes a shock when it is discharged into the ice heat storage tank 9 and changes its phase from a liquid phase to fluid sherbet-like ice. Therefore, the stacked heat exchanger 5 is continuously
The water is cooled until it becomes a supercooled state, and the phase changes to ice 9b in the ice heat storage tank 9, so that the sherbet-like ice 9b can be stored in the ice heat storage tank 9. Further, the temperature of the supercooled water can be controlled regardless of the amount of ice generated in the ice heat storage tank 9. In this embodiment, the ice making operation as described above is performed until the volume ratio of the sherbet-like ice 9b is about 60 to 80% in the ice making tank 9, and the density of the ice 9b is smaller than that of water. The sherbet-like ice 9b is in a form in which water is present in the lower part. In this embodiment, the water in the supercooled state is 0 ° C.
It can be produced in the range of -10 ° C, but when it is -5 ° C or less, the phase changes easily to ice even with a slight impact, so the lower limit of the set temperature is considered in consideration of the stability of the device. Was set to −5 ° C.

In the ice making operation according to the conventional method shown in FIG. 7, when the ice 9b on the surface of the heat exchanger grows as shown in FIG. The temperature drops to about −15 ° C., and the efficiency of the heat pump cycle is greatly reduced. If the heat exchanger that cools the water to the supercooled state is replaced with a plate heat exchanger or a double-tube heat exchanger that promotes heat transfer by turbulence, Can be generated, but the supercooled water phase changes to ice due to the drift or turbulence of the water in the flow path, and the flow path may be blocked. However, when the supercooled water is generated in the stacked heat exchanger 5, the temperature of the refrigerant flowing through the stacked heat exchanger 5 is −1 ° C. or more regardless of the amount of accumulated ice in the ice heat storage tank 9.
Since the temperature can be controlled in the range of −6 ° C., the efficiency of the heat pump cycle can be maintained in a highly efficient state, and the flow of the cooled water is laminar. Since the temperature distribution is substantially uniform, the supercooled water passes through the flow path without phase change to ice.

The ice 9b generated and accumulated in the ice heat storage tank 9
Is used for cooling the high-pressure refrigerant in order to improve the refrigerating effect of the heat pump cycle as in the conventional method. For example, when using the ice heat storage device of the present embodiment for cooling,
The evaporator 6 is an indoor unit. The refrigerant that has become a high-pressure liquid in the condenser 2 flows into the stacked heat exchanger 5 while maintaining a high pressure, and is cooled by the low-temperature water in the ice heat storage tank 9 sent by the circulation pump 10. At this time, the pressure reducing means 3a is set so that the pressure reduction width of the refrigerant is minimized. The water that has cooled the high-pressure refrigerant is discharged again to the ice heat storage tank, and is directly contacted with the generated sherbet-like ice 9b to be cooled. The refrigerant circuit is switched by the control of the three-way valves 7a and 7b, and the refrigerant flowing out of the stacked heat exchanger 5 passes through the decompression means 3b and the evaporator 6, and takes heat from the surroundings by the evaporator 6, and then the compressor 1 Return to In addition, as shown in FIG.
Can be directly sent to the evaporator 6 to perform cooling or cooling.

Further, as in the present embodiment, the water is forcibly fed into the stacked heat exchanger 5, so that the transfer of heat through the heat exchanger can be performed in comparison with the conventional method of making ice on the surface of the heat exchanger. Since the thermal characteristics are significantly improved, the heat transfer area can be reduced.

Further, the laminated heat exchanger 5 of this embodiment is
Since the internal volume is smaller than that of a coil-shaped or U-shaped heat exchanger or a plate-type heat exchanger, the amount of refrigerant to be charged can be reduced, and the size and weight of the device can be reduced.

Although the condenser 2 is air-cooled in this embodiment, it may be water-cooled. In this embodiment, water is used as the medium to be stored in the ice heat storage tank 9. However, the ice making operation can be performed by adding brine or the like to the water to lower the freezing point temperature. At this time, since heat can be stored at a lower temperature, the amount of energy that can be stored increases, and since the two-component medium has a different freezing point, it is possible to prevent the water circuit from being blocked by ice. The predetermined temperature T1 when brine is added to water can be set to a value according to the amount of brine added. Further, a liquid with another phase change may be used instead of water, depending on the use of the stored energy.

In this embodiment, the temperature of the water cooled by the stacked heat exchanger 5 is detected by a temperature sensor 12, and the control unit 13 controls the circulation pump so that the detected temperature becomes a predetermined temperature T1. To control the amount of water sent.
The set value of the predetermined temperature T1 is changed stepwise with the operation time in a range of -5 ° C or more. The predetermined temperature T at the beginning of operation
1 is set to a temperature higher than the freezing point, and the water 9 in the ice heat storage tank 9 is set.
After cooling a to a predetermined temperature T1, the predetermined temperature T1 is set to a temperature below the freezing point, and water in a supercooled state is generated in the stacked heat exchanger 5. It is also possible to set the predetermined temperature T1 to a temperature below the freezing point from the beginning of operation,
Regardless of the setting, water in a supercooled state is generated from the stacked heat exchanger 5, and sherbet-like ice is accumulated in the ice heat storage tank 9. The amount of circulating water can be controlled by installing a flow control valve in the water circuit 11 in addition to controlling the circulation pump. Further, an inverter circuit is provided in the compressor 1 so that the temperature of the water to be cooled is set to a predetermined temperature T.
The same effect can be obtained even if the output of the compressor 1 is controlled to be 1.

The amount of water circulating so that the temperature of the water cooled by the stacked heat exchanger 5 becomes a predetermined temperature T1 or the temperature of the water in the ice heat storage tank 9 without controlling the compressor 1. After a certain time, supercooled water is generated from the laminated heat exchanger 5 and sherbet-like ice is accumulated in the ice heat storage tank 9. Therefore, simplification of the apparatus and cost reduction can be achieved. However, the temperature of the supercooled water generated in the stacked heat exchanger 5 decreases with the operation time, and the water in the supercooled state is more likely to change into ice as the temperature is lowered. When cooled to a temperature close to, water changed phase into ice in the flow path of the heat exchanger and closed the flow path. Therefore, the cost of the apparatus can be reduced, but the amount of ice that can be stored in the ice heat storage tank 9 decreases, and the stability of the apparatus decreases.

Although the refrigerant and the water exchange heat in the present embodiment, a configuration in which the high-temperature fluid exchanges heat with the low-temperature fluid and the high-temperature fluid is cooled to a supercooled state is also possible.
Further, in the present embodiment, the heat pump circuit is configured by a compression cycle in which the refrigerant is circulated by using the compressor 1, but the refrigerant is absorbed in the absorbent by the absorber to generate the refrigerant in the regenerator. The same effect can be obtained by using an absorption cycle.

Further, in this embodiment, the water in the ice heat storage tank is circulated by using the circulation pump 10, but it is also possible to use a natural circulation type by utilizing the head difference of the water surface of the ice heat storage tank. Thus, the cost of the apparatus can be reduced.

Although the laminated heat exchanger 5 of the present embodiment has a counter flow, a similar effect can be obtained even if the cross flow is a cross flow or a flat flow.

Here, when the condenser 2 is of a water-cooled type and hot water generated during the ice making operation is used for hot water supply, the running cost can be further reduced. In addition, the refrigerant of the heat pump circuit includes the compressor 1, the laminated heat exchanger 5, the pressure reducing valve 3.
When the refrigerant circuit configuration has a reverse flow such that the refrigerant circulates in the order of a and the condenser 2, the water in the ice heat storage tank is heated by the laminated heat exchanger 5, and the hot water is stored. The hot water stored in the ice heat storage tank can be used for heating.

(Embodiment 2) FIG. 5 schematically shows an ice heat storage device according to Embodiment 2 of the present invention. In this embodiment, components having the same reference numerals as those of Embodiment 1 have the same functions. I have. This embodiment is different from the first embodiment in that the stacked heat exchanger 23 and the precooled heat exchanger 24 are replaced with the stacked heat exchanger 5.
Was provided. The pre-cooling heat exchanger 24 was installed at the inlet of the water circuit 11 of the laminated heat exchanger 23 in order to pre-cool the water sent from the circulation pump 10 to the laminated heat exchanger 23. The pre-cooling heat exchanger 24 can be a plate heat exchanger or a double-pipe heat exchanger other than the stacked heat exchanger. In this embodiment, a double-pipe heat exchanger is employed.

The operation and operation of this configuration will be described below. The water in the ice heat storage tank 9 is sent by the circulation pump 10 to the pre-cooling heat exchanger 24 and the stacked heat exchanger 23 in this order. The water that has flowed into the pre-cooling heat exchanger 24 exchanges heat with the refrigerant in the heat pump circuit to be cooled to a temperature close to the freezing point, and then further cooled to a temperature below the freezing point by the stacked heat exchanger 23. The flow of the water flowing through the water flow path of the stacked heat exchanger 23 is laminar, and the flow boundary height is small, so that the temperature boundary layer is thinned. Is in a uniform state. As described in the first embodiment, the water flowing through the stacked heat exchanger 23 does not freeze even when cooled to a temperature below the freezing point, and is in a supercooled state of a liquid phase. The supercooled water undergoes a phase change from water to ice instantly upon receiving an impact such as turbulence in the flow. However, since the flow of water in the stacked heat exchanger 23 is laminar,
Even if the water is in a supercooled state, it flows through the flow path without phase change to ice. The water in the supercooled state is discharged into the ice heat storage tank 9 after flowing out of the laminated heat exchanger 23, and is subjected to a shock when the water is discharged into the ice heat storage tank 9. The phase changes to ice 9b. Accordingly, the water is pre-cooled by the pre-cooling heat exchanger 24, and then cooled by the laminated heat exchanger 23 until the water is in a supercooled state, and the phase of the water is changed to the ice 9b in the ice heat storage tank 9, whereby the sherbet-like ice is formed. 9b can be stored in the ice heat storage tank 9.

The stacked heat exchanger 23 is provided for cooling the water cooled by the pre-cooling heat exchanger 24 to a temperature below the freezing point. The heat transfer area of the stacked heat exchanger 23 is It can be smaller than the exchanger 5. Furthermore, supercooled water can be generated by installing the laminated heat exchanger 23 at the chilled water outlet of the heat exchanger that generates chilled water of the conventional chilled water heat storage device, and the chilled water heat storage device can be cooled by ice. It can be a device. In addition, the high efficiency and high output of the apparatus for performing ice heat storage using the stacked heat exchanger 5 are achieved by installing a double tube heat exchanger or a plate heat exchanger at the water circuit inlet of the stacked heat exchanger 5. It can be easily realized by installing a pre-cooling heat exchanger such as a heat exchanger,
There is no need to change the design of the stacked heat exchanger 5.

In this embodiment, the refrigerant is the pre-cooled heat exchanger 2
4. Refrigerant circuit 8 so that it flows in the order of stacked heat exchanger 23
However, if the configuration is such that the flow of water flows in the order of the pre-cooling heat exchanger 24 and the stacked heat exchanger 23, the flow of the refrigerant will be in the order of the stacked heat exchanger 23 and the pre-cooling heat exchanger 24. It is good also as a structure of the refrigerant circuit 8 which flows by.

(Embodiment 3) FIG. 6 schematically shows an ice heat storage device according to Embodiment 3 of the present invention. In this embodiment, components having the same reference numerals as those of Embodiment 2 have the same functions. I have. In the present embodiment, a pressure reducing valve 25 is provided in a refrigerant circuit connecting the stacked heat exchanger 23 and the pre-cooling heat exchanger 24 having the configuration of the second embodiment.

The operation and operation of this configuration will be described below. As in the second embodiment, the water in the ice heat storage tank 9 is sent by the circulation pump 10 to the pre-cooling heat exchanger 24 and the stacked heat exchanger 23 in this order. After exchanging heat with the refrigerant and cooling to a temperature close to the freezing point, the laminated heat exchanger 23 cools to a temperature below the freezing point. The water flowing through the laminated heat exchanger 23 does not freeze even when cooled to a temperature below the freezing point, and is in a supercooled state, which is a liquid phase. Phase changes to sexual sherbet-like ice. In the configuration of the second embodiment, the refrigerant flowing through the stacked heat exchanger 23 is decompressed by the decompression means 3a so as to have a temperature lower than the freezing point of water in order to cool the water to a temperature below the freezing point. When the pre-cooling heat exchanger 24 is a double tube heat exchanger or a plate heat exchanger, the flow of water in the flow path is turbulent, and the height of the flow path is higher than that of the stacked heat exchanger. Therefore, a temperature distribution is formed in the flow channel height direction. Therefore, the temperature of the refrigerant depressurized by the decompression means 3a becomes lower than the freezing point of water, and
When the water flows into the heat exchanger 4, even if the main flow temperature of the water is higher than the freezing point temperature, the temperature near the heat transfer wall surface of the heat exchanger is in a supercooled state lower than the freezing point temperature, and the flow of the water is turbulent. Therefore, the supercooled water near the heat transfer wall changes its phase to ice. If ice is generated in the precooling heat exchanger 24, not only does the heat transfer performance of the preheating heat exchanger deteriorate,
The generation of supercooled water becomes impossible in the stacked heat exchanger 23. Therefore, as shown in FIG. 6, a pressure reducing means 25 is provided in a refrigerant circuit connecting the pre-cooling heat exchanger 24 and the stacked heat exchanger 23, and the high-pressure refrigerant liquefied in the condenser 2 is depressurized by the pressure reducing means 3a from the freezing point of water. The pressure is reduced so that the temperature does not become low, and the pressure is further reduced by the pressure reducing means 25 to a temperature lower than the freezing point of water. Since the temperature of the refrigerant flowing through the pre-cooling heat exchanger 24 is higher than the freezing point of water, the temperature of the water near the heat transfer wall surface of the heat exchanger is prevented from being cooled below the freezing point of water. You can do it.

[0042]

As described above, the following effects can be obtained in the ice heat storage device having the configuration as in the present invention.

According to the first and second aspects of the present invention, since the amount of ice accumulated in the ice heat storage tank and the temperature of the low-pressure refrigerant become irrelevant, the ice heat storage for performing extra-ice ice making with a liquid-filled evaporator is used. The ice making operation can be performed with higher efficiency as compared with the apparatus.
Further, the generated supercooled water can be sent to the ice heat storage tank without blocking the flow path, so that the stability and durability of the device are improved. Furthermore, since the stacked heat exchanger has a smaller internal volume than the liquid-filled evaporator and the plate heat exchanger, the amount of refrigerant to be charged can be reduced, and the size, weight and cost of the device are reduced. Can be.

According to the third aspect of the present invention, since the pre-cooling heat exchanger is provided at the inlet of the water circuit of the stacked heat exchanger, the stacked heat exchanger is reduced in size, and the efficiency of the apparatus is improved. And high output can be easily realized at low cost. Furthermore, it is possible to change to a high-efficiency ice heat storage device simply by adding a stacked heat exchanger to the conventional water heat storage device.

According to the fourth aspect of the present invention, not only the miniaturization of the stacked heat exchanger and the high efficiency and high output of the device can be realized at low cost, but also the stability of the device. Is improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an ice heat storage device according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective view of the stacked heat exchanger of the ice heat storage device.

FIG. 3 is a graph showing refrigerant temperature and efficiency in Embodiment 1 of the present invention.

FIG. 4 is a configuration diagram of an ice heat storage device according to the first embodiment of the present invention.

FIG. 5 is a configuration diagram of an ice heat storage device according to a second embodiment of the present invention.

FIG. 6 is a configuration diagram of an ice heat storage device according to a third embodiment of the present invention.

FIG. 7 is a configuration diagram of a conventional ice heat storage device.

FIG. 8 is a configuration diagram of a conventional ice heat storage device.

FIG. 9 is a configuration diagram of a conventional ice heat storage device.

FIG. 10 is a configuration diagram of a conventional ice heat storage device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 2 Condenser 3a, 3b, 25 Decompression means 4a, 30 Ice making heat exchanger 5, 23 Stacking type heat exchanger 6 Evaporator 8 Refrigerant circuit 9 Ice heat storage tank 9a Water 9b Ice 11, 21, 22 Water circuit 15 Refrigerant plate 15a Refrigerant passage slit 15b Water passage slit 16 Partition plate 16a Refrigerant passage slit 16b Water passage slit 17 Water plate 17a Refrigerant passage slit 17b Water passage slit 24 Pre-cooling heat exchanger

Claims (4)

[Claims] 1. A heat pump circuit in which a compressor, a condenser, a decompression means, and an ice making heat exchanger are connected in order by a refrigerant circuit, an ice heat storage tank for storing water, and water in the ice heat storage tank using an ice making heat exchanger. An ice heat storage device, comprising: a water circuit that exchanges heat with a refrigerant of a heat pump circuit to cool to a supercooled state and then returns to an ice heat storage tank, wherein the ice making heat exchanger is a stacked heat exchanger. 2. The laminated heat exchanger is provided with a plurality of refrigerant plates having slit-shaped holes, a plurality of water plates having slit-shaped holes, and between the plurality of refrigerant plates and the water plates. The ice heat storage device according to claim 1, wherein a refrigerant flow path and a water flow path are formed by a plurality of partition plates forming a partition wall between the refrigerant and the water. 3. A pre-cooling heat exchanger for cooling water by exchanging water in an ice heat storage tank with a refrigerant in a heat pump circuit at an inlet of a water circuit of the stacked heat exchanger. Ice thermal storage device. 4. A refrigerant circuit for sequentially connecting a pre-cooling heat exchanger and a stacked heat exchanger is provided, and the refrigerant circuit between the pre-cooling heat exchanger and the stacked heat exchanger is provided with a pressure reducing means. The ice heat storage device according to claim 3, wherein