JPH10122703A - Plate type of heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid troubles caused by freezing inside a plate-type heat exchanger even in case that this plate-type heat exchanger is used as a supercooled water producing heat exchanger by modifying the plate-type heat exchanger. SOLUTION: A plate type heat exchanger is applied as a supercooled water producing heat exchanger used for an ice storage device producing ice by the supercool-dissolving action of supercooled water. A heat transfer plates 53-58 are made in a flat plate shape, and bends 70, 70,... extending in the direction of the fluid circulation are made at its flat plate part 69. The tips of this bends 70, 70,... are brazed to the plate part 69 of the adjacent heat transfer plates 53-58, whereby circulation paths A and B having a same section form along the direction of fluid circulation are made between the heat transfer plates 53-58.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plate-type heat exchanger, and more particularly to an improvement in the shape of a flow path of a heat exchange fluid.

[0002]

2. Description of the Related Art Conventionally, as an example of an ice heat storage device provided in an ice heat storage type air conditioner or the like, as disclosed in Japanese Patent Application Laid-Open No. 4-251177, for example, a compressor and a condenser are disclosed. A refrigerant circulation circuit formed by sequentially connecting an expansion mechanism and a refrigerant heat exchange unit by a refrigerant pipe, and a heat storage tank,
There is known an apparatus provided with a water circulation circuit formed by sequentially connecting a heat storage medium heat exchange section capable of exchanging heat with the refrigerant heat exchange section and a supercooling elimination section by a water pipe.

[0003] In the ice making operation of this type of ice heat storage device, water (heat storage medium) taken out from a heat storage tank to a water pipe is heat-exchanged with a refrigerant in a refrigerant heat exchange unit in a heat storage medium heat exchange unit. Cooling is performed to a cooling state, and the supercooled state is eliminated in the supercooling elimination section to generate slurry ice. Then, the ice is supplied to and stored in the heat storage tank.

[0004] The heat storage medium heat exchange section and the refrigerant heat exchange section are generally integrally formed by a shell and tube type heat exchanger.

By the way, a plate type heat exchanger is generally known as a heat exchanger other than this type of heat exchanger, and the inventors of the present invention have proposed that the plate type heat exchanger is provided with heat for generating supercooled water. The use as an exchanger was discussed.

The general structure of this plate type heat exchanger will be described. A plurality of heat transfer plates are superimposed, and a fluid passage is formed between these heat transfer plates. By setting one of the flow paths adjacent to the heat transfer plate therebetween as the high-temperature flow path and the other as the low-temperature flow path, heat exchange is performed between the flow paths. Further, each heat transfer plate is formed in a corrugated plate shape, and the wave shapes of adjacent heat transfer plates, particularly, the extending directions of the waves are different from each other. For this reason, the fluid flows while being stirred in each flow path, and heat exchange is performed between the high-temperature side fluid and the low-temperature side fluid with a high heat transfer coefficient. With such a configuration, this plate-type heat exchanger can secure a large heat transfer area while reducing the overall size as compared with the shell-and-tube type heat exchanger, and can reduce the number of stacked heat transfer plates. There is an advantage that the heat transfer area can be easily increased / decreased by changing.

[0007]

However, when the above-mentioned conventional plate-type heat exchanger is used as it is as the heat exchanger for generating the supercooled water in the above-mentioned ice heat storage device, the following will be described. There are issues.

During the ice making operation, the supercooled water is agitated, and the supercooling elimination operation is performed by the impact of this agitation, and ice is generated in portions other than the subcooling elimination section. Therefore, not only the ice making operation is not performed stably, but also the ice is attached to the heat transfer plate and grows, causing freezing, and the ice making operation may be disabled.

In general, since the heat transfer plate is manufactured by press working, work hardening occurs, and elastic deformation due to volume expansion due to ice during freezing hardly occurs, and the plate is plastically deformed. It was highly likely that In particular, in the case where both plates are brazed to each other, since the plates are joined at many places, there is almost no area where elastic deformation is possible, and plastic deformation of the plates is likely to occur. Further, in the case where the gasket seals the space between the two plates, the gasket may be damaged by the deformation of the plate due to the freezing, and the sealing performance of the flow path between the two plates may be deteriorated.

[0010] The present invention has been made in view of such a point, and an object of the present invention is to improve the plate-type heat exchanger so that even when used as a supercooled water generating heat exchanger, An object of the present invention is to avoid a problem caused by freezing inside the inside.

[0011]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is directed to a plate type heat exchanger in which a fluid passage is provided in such a manner that the fluid flows with little turbulence, and water flows through the fluid passage. Thus, it is possible to prevent the supercooled water from flowing in a state where the turbulence is large and to avoid the occurrence of freezing.

More specifically, the means implemented by the invention according to claim 1 is that a plurality of heat transfer plates (53 to 58) are superimposed and a fluid passage (A, A) is provided between the heat transfer plates (53 to 58). B) is formed, and it is assumed that a plate-type heat exchanger in which fluids flowing in fluid passages (A, B) adjacent to each other exchange heat via heat transfer plates (53 to 58). A fluid passage (B) through which at least one of the fluid passages (A, B) through which the fluids performing heat exchange flow have a uniform cross-sectional shape throughout the flow direction. I have.

According to a second aspect of the present invention, in the plate type heat exchanger of the first aspect, the first fluid and the second fluid are respectively circulated through the fluid passages (A, B) adjacent to each other. , The second fluid is cooled to a supercooled state. And a fluid passage for the second fluid.
(B) is formed to have a uniform cross-sectional shape throughout the fluid flow direction.

According to these specific items, for example, the heat exchanger of the present invention is used as a heat exchanger for exchanging heat between water and a refrigerant to bring the water into a supercooled state, and the water (second fluid)
Is made to flow through the fluid passage (B) having a uniform cross section in the flow direction, so that the supercooled water flows with little turbulence. For this reason, it is possible to avoid performing the supercooling elimination operation by stirring the supercooled water, and to avoid freezing of the heat exchanger.

According to a third aspect of the present invention, there is provided the plate type heat exchanger according to the first aspect, wherein the heat transfer plates (53 to 5) are provided.
8) The flat plate (69) and the adjacent heat transfer plates (53-58)
And a passage forming portion (70, 70,...) Interposed at a predetermined interval between the flat plate portions (69).

According to this specific matter, the passage forming portion (7) is formed between the flat plate portions (69, 69) of the adjacent heat transfer plates (53-58).
0,70,...), Fluid passages (A, B) having a uniform cross-sectional shape are formed throughout the flow direction, and heat exchange is performed in the same manner as in the above-described operation according to the first aspect. Freezing of the vessel is avoided. Also, if freezing occurs in a part of the fluid passage, the heat transfer plate (53
In this case, if the flat plate portion (69) of the heat transfer plate (53-58) is set to a relatively large area, the elastic deformation area for the above stress becomes large. As a result, plastic deformation of the heat transfer plates (53 to 58) can be avoided.

According to a fourth aspect of the present invention, in the plate heat exchanger according to the third aspect, a refrigerant and water are respectively circulated through the fluid passages (A, B) adjacent to each other, and the heat exchange between the two is performed. , So that the water is cooled to a supercooled state. In addition, the passage forming portions (70, 70, 70) of the heat transfer plates (53-58)
) Are bent so that a part of the plates (53-58) protrudes in one direction in the plate thickness direction, and are integrally formed with the flat plate portion (69). The protruding side of the flow path forming portion (70, 70, ...) is positioned in the water side passage (B), and the adjacent heat transfer plate (53
58) to the flat plate portion (69).

According to this specific matter, the cross-sectional shape of the water-side passage can be set to a relatively simple shape such as a rectangular shape.
This cross section can be prevented from having a complicated shape. For this reason, the portion where water easily stays in the water-side passage can be reduced, and it is possible to prevent the supercooling elimination operation from being performed by local cooling due to the water staying.

According to a fifth aspect of the present invention, a plurality of heat transfer plates (80, 80,...)
80, ...) are formed between the fluid transfer plates (80,
80,…)). The fluid passages (A, B) have a first passage portion (A) having a larger passage cross-sectional area, and a second passage portion having a passage cross-sectional area smaller than the first passage portion (A). Department
(B), the first passage portion (A) and the second passage portion
And (B) are adjacent to each other.

According to a sixth aspect of the present invention, in the plate heat exchanger according to the fifth aspect, the first passage portion (A) and the second passage portion (B) are uniformly formed throughout the flow direction. It is configured to have a simple cross-sectional shape.

According to a seventh aspect of the present invention, in the plate type heat exchanger according to the fifth or sixth aspect, the first fluid and the second fluid are respectively circulated through the fluid passages (A, B) adjacent to each other, By the heat exchange between the two, the second fluid is cooled to a supercooled state. The fluid passage of the first fluid is provided with a first passage portion (A) having a large passage cross-sectional area, and the fluid passage of the second fluid has a smaller passage cross-sectional area than the first passage portion (A). The second passage portion (B) is provided.

According to these specific items, each passage (A, B)
Of the fluid flowing through the second passage having a small passage cross-sectional area
When the fluid in the passage (B) becomes iced, the second passage (B)
Are applied to the heat transfer plates (80, 80,...), The second passage portion (B) is adjacent to the first passage portion (A) having a large passage cross-sectional area. Therefore, a large elastically deformable area against the above stress is secured, and plastic deformation of the heat transfer plates (53 to 58) can be avoided.

[0023] The invention according to claim 8 is the invention according to claims 5 and 6.
Or a first heat exchanger (81, 81, ...) curved so as to swell in one direction in the thickness direction of the heat transfer plate (80, 80, ...). The second curved portions (82, 82,...) Which are curved so as to bulge in the other direction are formed in a wave shape alternately formed. The first curved portions (81, 81,...) Of the heat transfer plates (80, 80) adjacent to each other and the second
The curved portions (82, 82,...) Are opposed to each other to form a fluid flow path (A, B) between the two plates (80, 80). And
The first fluid and the second fluid are allowed to flow through the fluid passages (A, B) adjacent to each other, and the second fluid is cooled to a supercooled state by heat exchange between the two. Further, a first curved portion (81, 81,...) And a second curved portion (82, 82,.
..), The curved portions (81, 82) are brought into contact with each other in the portion facing the fluid passage (B) of the second fluid, while the curved portions (81, 82) are brought into contact with each other in the portion facing the fluid passage (A) of the first fluid. A gap is formed between the curved portions (81, 82).

[0024] With this specific matter, a specific configuration for forming each passage portion is obtained.

According to a ninth aspect of the present invention, in the plate-type heat exchanger according to the seventh or eighth aspect, the first fluid is a refrigerant for performing heat exchange with the second fluid, and the second fluid is water. The configuration is as follows.

According to this particular matter, the fluid flowing through each passage can be embodied.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.

First, the heat storage type air conditioner (10) using the heat exchanger (50) of the present invention will be described.

As shown in FIG. 1, a regenerative air conditioner (1
0) includes a refrigerant circuit (20) for circulating a refrigerant and a water circuit (30) for circulating water. First, the refrigerant circuit (20) and the water circuit (30) will be described in order.

-Refrigerant circuit (20)-The refrigerant circuit (20) comprises a compressor (21) and a four-way switching valve (22).
The outdoor heat exchanger (23), the outdoor electric expansion valve (EV-1) and the indoor electric expansion valve (EV-2), the indoor heat exchanger (24), and the accumulator (25) are connected to the refrigerant pipe ( A main refrigerant circuit (27), which is connected in order by 26) and is capable of reversible operation, is provided. And the indoor heat exchanger (24) and the indoor electric expansion valve (EV-2)
Is provided in the indoor unit, while other component devices such as the compressor (21) are provided in the outdoor unit.

Further, the refrigerant circulation circuit (20) is provided with a heat storage refrigerant circuit (2a), an ice core circuit (2b), and a hot gas passage (2c). The heat storage refrigerant circuit (2a) is a circuit in which the refrigerant circulates during a cold storage operation or a cooling operation using cold storage, and has one end having an outdoor heat exchanger (23) and an outdoor electric expansion valve (EV-
The other end is between the four-way switching valve (22) and the accumulator (2).
5), a first solenoid valve (SV-1), a preheater (11), a heat storage electric expansion valve (EV-3) as an expansion mechanism,
The supercooling heat exchanger (50) and the second solenoid valve (SV-2) are sequentially connected.

The ice core circuit (2b) includes a water circulation circuit described later.
A circuit for generating ice nuclei in (30), one end of which is between the heat storage electric expansion valve (EV-3) and the supercooling heat exchanger (50) in the heat storage refrigerant circuit (2a), and the other end. Is a subcooling heat exchanger (50)
And a second solenoid valve (SV-2), and a capillary tube (CP) and an ice nucleus generator (13) are connected in order.

The hot gas passage (2c) is used to cool the refrigerant discharged from the compressor (21) during a cooling operation utilizing cold heat storage, etc.
(50), one end of which is on the discharge side of the compressor (21), and the other end of which is the second solenoid valve (SV-) in the heat storage refrigerant circuit (2a).
A third solenoid valve connected between 2) and the subcooling heat exchanger (50)
(SV-3).

-Water circulation circuit (30)-The water circulation circuit (30) has a heat storage tank (31) as shown in FIG.
, A pump (32), a preheater (11), a mixer (33), a subcooling heat exchanger (50), and a subcooling elimination section (34) by a water pipe (35) with a heat medium. A certain water circulation (see the arrow in FIG. 2) is connected in order so as to be possible.

And, the supercooling heat exchanger according to the present invention
(50) is a plate-type heat exchanger, as will be described later, which allows heat exchange between the refrigerant flowing through the refrigerant circulation circuit (20) and the water flowing through the water circulation circuit (30) to perform a cold heat storage operation. Sometimes it is configured to cool the water to a supercooled state.

The preheater (11) is a double-pipe heat exchanger, in which a coolant flows outside the inner pipe, water flows inside the inner pipe, and ice water flowing from the heat storage tank (31) is removed. Heating and water plumbing
It is configured to melt ice flowing through (35).

The ice nucleus generator (13) includes a subcooling heat exchanger (5).
0) is attached to the water pipe (35) at the downstream side, and a part of the water flowing through the water pipe (35) is cooled and iced by the refrigerant in the refrigerant circuit (20), and it is supercooled as ice nuclei. It is configured to supply the solution to the cancellation section (34).

The mixer (33) and the subcooling eliminating section (34)
Each is constituted by a hollow cylindrical container, and is configured such that water introduced in a tangential direction forms a swirling flow. And
The mixer (33) stirs the water and ice heated by the preheater (11) to promote the melting of the ice, while the supercooling elimination unit (34)
Is the ice nucleus generated by the ice nucleator (13) and the supercooled heat exchanger
The supercooling water generated in (50) is stirred to eliminate supercooling.

-Supercooling heat exchanger (50)-Next, the supercooling heat exchanger (50) will be described.

As shown in FIG. 3 (exploded perspective view of the heat exchanger), the supercooling heat exchanger (50) is of a plate type. Specifically, a plurality of heat transfer plates (53 to 58) are superimposed between two frames (51, 52), and a fluid flow path (A, B) is formed between the heat transfer plates (53 to 58). Has formed.

Hereinafter, the cross-sectional shape of each of the heat transfer plates (53-58) and the flow paths (A, B) formed by the heat transfer plates (53-58) will be described with reference to FIG. FIG. 4 is a cross-sectional view of a state in which the heat transfer plates (53 to 56) are superimposed to form the respective flow paths (A, B) as viewed from above (the cross-sectional hatching of the heat transfer plate is omitted). Is).

As shown in FIG. 4, the heat transfer plates (53 to 58) are made of a substantially flat plate material, and are provided at a plurality of positions in the horizontal direction (the left-right direction in FIG. 4) in the vertical direction (the direction in FIG. 4). The bent portions (70, 70, ...) extending in the direction perpendicular to the paper are formed by press working. In other words, these heat transfer plates (53 to 5
8) includes a flat plate portion (69) and bent portions (70, 70, ...) formed at predetermined intervals in the flat plate portion (69). The bent portions (70) are bent in a mountain shape so as to project in the same direction (upward in FIG. 4). Then, each heat transfer plate (53
Are overlapped while the positions of the bent portions (70, 70,...) Are different from each other, so that the flow paths having the same cross-sectional shape are respectively formed between the adjacent heat transfer plates (53 to 58).
(A, B) is formed. More specifically, in FIG. 4, each bent portion (70) of the heat transfer plate (54-58) positioned below the heat transfer plate (53-58) adjacent vertically
Of the heat transfer plate (53 to 5
7) is joined by brazing at an intermediate position between the bent portions (70, 70) on the back surface of (7). The flow passages located on both outer sides and the center of the heat transfer plates (53 to 57) in the thickness direction (vertical direction in FIG. 4) are water flow passages (B), and the other flow passages are refrigerants. (A). Also, these bent portions (70, 70,...) Are not formed at the upstream end portion and the downstream end portion of the heat transfer plates (53-58). Refrigerant flow path which is a flow path
(A, A,...) And the water flow paths (B, B,...) Merge at the upper and lower ends of the heat transfer plates (53 to 58).

As described above, the flow paths (A, B) formed between the heat transfer plates (53 to 58) have the same cross-sectional shape, and have the same shape as the flow paths (A, B). , B) each have a uniform cross-sectional shape throughout the vertical direction. For this reason, the refrigerant and the water flowing in each of the flow paths (A, B) flow with very little disturbance.

Each heat transfer plate (53-58) has openings (61-64) at four corners. Each of these openings (61-6
4) is a first opening (61) located at the lower left in FIG. 3, a second opening (62) located at the upper right, and a third opening (6) located at the lower right.
3) Consists of a fourth opening (64) located at the upper left.

In the first plate (53) located on the most front side in FIG. 3, a seal portion (71) is formed so as to surround the periphery of each of the openings (61 to 64). This seal (7
1) is such that the periphery of each opening (61 to 64) protrudes toward the frame (51), and a seal portion (71) formed by this protruding portion is formed.
Abuts on the frame (51) so that each of these openings (61 to 6
4) The area around is sealed.

The periphery of the first opening (61) and the second opening (62) are located between the first plate (53) and the second plate (54) located second from the front in FIG. A seal portion (72) is formed so as to surround the periphery. In other words, this first
A third opening is provided between the plate (53) and the second plate (54).
Fluid (water) can flow between the (63) and the fourth opening (64). On the other hand, the periphery of the third opening (63) and the periphery of the fourth opening (64) are provided between the second plate (54) and the third plate (55) adjacent to the back side in FIG. A seal portion (73) is formed so as to surround. In other words, this second plate
A fluid (refrigerant) can flow between the first opening (61) and the second opening (62) between the (54) and the third plate (55). In this way, the heat transfer plates (53 to 58) are overlapped so that different fluids (water, refrigerant) flow in adjacent flow paths, and these are integrally brazed. This brazing portion is the peripheral portion of each of the above-mentioned seal portions (71, 72, 73) and each of the heat transfer plates (53 to 58).

Further, one frame (front side in FIG. 3) (5
In (1), pipes (75 to 7) corresponding to the above openings (61 to 64)
8) is connected. Piping (7) corresponding to the first opening (61)
5) is a refrigerant introduction pipe, a pipe (76) corresponding to the second opening (62) is a refrigerant outlet pipe, a pipe (77) corresponding to the third opening (63) is a water introduction pipe, and a fourth opening (64). The corresponding pipe (78) is a water outlet pipe.

With such a structure, the fluid flow paths (A, B) formed between the heat transfer plates (53 to 58) are formed.
The refrigerant flow passages (A) and the water flow passages (B) are alternately formed. That is, the refrigerant flows through the refrigerant flow passages (A, A) from the first openings (61, 61,...) Through the refrigerant introduction pipe (75) as indicated by solid arrows in FIG. Second opening (62,6
2,...) Through the refrigerant outlet pipe (76). Similarly, the water flows through each of the third openings (63, 63,...) Through the water introduction pipe (77) through the water flow passage (B) as indicated by the dashed arrow in FIG. Opening (64,64,
…)) And is led out from the water outlet pipe (78). In this way, the refrigerant and the water exchange heat through the heat transfer plates (53 to 58).

-Operating operation- Next, the operating operation of the regenerative air conditioner (10) will be described. First, a cold storage operation using the supercooling heat exchanger (50) will be described.

-Cold heat storage operation- In this operation mode, as shown in FIG.
2) is switched to the solid line side, and while the heat storage electric expansion valve (EV-3) is adjusted to the predetermined opening, the other electric expansion valves (EV-1, EV-
2) Close. Also, the first and second solenoid valves (SV-1, SV-
2) is open, and the third solenoid valve (SV-3) is closed.

In this state, in the refrigerant circuit (20), the refrigerant discharged from the compressor (21) exchanges heat with the outside air in the outdoor heat exchanger (23) as shown by arrows in FIG. I do. After that, this refrigerant is decompressed by the heat storage electric expansion valve (EV-3), and then exchanges heat with water in the supercooling heat exchanger (50) to evaporate.
The water is cooled to a supercooled state (eg -2 ° C). Thereafter, the refrigerant passes through the accumulator (25) and the compressor (21)
Inhaled.

In this operation, a part of the refrigerant is
After being diverted from the downstream side of the heat storage electric expansion valve (EV-3) to the ice nucleus circuit (2b), the pressure was reduced by the capillary tube (CP), and then evaporated by the ice nucleus generator (13), and the accumulator (25) was removed. Via compressor
Inhaled in (21). In this ice nucleus generator (13), the refrigerant exchanges heat with the water flowing through the water pipe (35), and the ice blocks are removed from the water pipe (3).
Generated on the inner wall of 5).

On the other hand, in the water circulation circuit (30), water is circulated by driving the pump (32). The water flowing out of the heat storage tank (31) is heated by a preheater (11) via a pump (32), and then stirred by a mixer (33). After that, the water is cooled by exchanging heat with the refrigerant in the subcooling heat exchanger (50), enters a predetermined supercooling state, and flows out of the supercooling heat exchanger (50).
And the supercooled water flowing out of the heat exchanger (50)
Further cooled in the ice nucleus generator (13),
Generated on the inner wall of 5). After that, ice nuclei are generated around the ice block, and the supercooled water containing the ice nuclei is
(34). Then, the ice nuclei and the supercooled water are stirred in the supercooling elimination section (34), and slurry-like ice for heat storage is generated and collected and stored in the heat storage tank (31).

At the time of the main operation, a relatively high-temperature refrigerant flows through the preheater (11), and even if ice flows through the water pipe (35), even if the preheater (1)
In step (1), the mixture is heated and melted, and ice is prevented from entering the supercooled heat exchanger (50).

At this time, the flow of the refrigerant and water in the subcooling heat exchanger (50) is, as described above, each of the flow paths (A, B) inside the subcooling heat exchanger (50). Since the refrigerant and the water flowing through each flow path (A, B) are formed in a state of small turbulence, they are formed in a uniform sectional shape over the entire vertical direction. Therefore, the supercooled water in the water flow path (B) flows out of the supercooling heat exchanger (50) with little disturbance. That is, the occurrence of a situation in which the supercooling is eliminated by the impact due to the large turbulence of the water flow is avoided. Therefore, generation of freezing inside the subcooling heat exchanger (50) can be avoided, and a stable operation of generating supercooled water can be performed.

As described above, the cold storage operation using the supercooling heat exchanger (50) is performed.

Next, another operation of the regenerative air conditioner (10) will be schematically described.

-Normal Cooling Operation- In this operation mode, only the refrigerant circuit (20) is operated, and the water circuit (30) is not operated.

In this operation mode, the four-way switching valve (22) is switched to the solid line side in FIG. 1, the indoor electric expansion valve (EV-2) is superheated, and the outdoor electric expansion valve (EV-1) is turned on. The heat storage electric expansion valve (EV-3) is controlled to a fully closed state and to a fully closed state. On the other hand, each solenoid valve (SV-1, SV-2, SV-3) is closed.

In this state, the refrigerant discharged from the compressor (21) exchanges heat with the outside air in the outdoor heat exchanger (23) and condenses. After that, the refrigerant is decompressed by the indoor electric expansion valve (EV-2), and then evaporates in the indoor heat exchanger (24) to produce an accumulator.
Through (25), it is sucked into the compressor (21). By this circulation operation, the regenerative air conditioner (10) cools the room.

-Cooling operation utilizing cold storage- In this operation mode, as shown in FIG.
2) is switched to the solid line side, the indoor electric expansion valve (EV-2) is controlled to a predetermined opening, and the other electric expansion valves (EV-1, EV-3) are fully opened. Further, the first and third solenoid valves (SV-1 and SV-3) are opened, and the second solenoid valve (SV-2) is closed.

In this state, in the water circulation circuit (30),
The pump (32) is driven to circulate cold water. The cold water in the heat storage tank (31) passes through the pump (32), the preheater (11), and the mixer (33) in this order, and then flows into the supercooling heat exchanger (50). Then, the cold water flowing into the subcooling heat exchanger (50) exchanges heat with the refrigerant and is heated. Thereafter, the heated water flows out of the subcooling heat exchanger (50), and returns to the heat storage tank (31) via the subcooling elimination section (34). The heated water exchanges heat with ice stored in the heat storage tank (31) to be cooled, becomes cold water, flows out of the heat storage tank (31) again, and circulates in the water circulation circuit.

On the other hand, in the refrigerant circuit (20), a part of the refrigerant discharged from the compressor (21) passes through the four-way switching valve (22) as shown by the arrow in FIG. Heat exchanger (2
It flows to 3) and exchanges heat with the outside air in the outdoor heat exchanger (23) to condense. Further, the other discharged refrigerant flows into the supercooling heat exchanger (50) through the hot gas passage (2c), and exchanges heat with cold water circulating in the water circulation circuit (30) to condense. Then, the refrigerant condensed in the outdoor heat exchanger (23) and the subcooling heat exchanger (50) are merged and decompressed by the indoor electric expansion valve (EV-2), and then the indoor heat exchanger (24) After evaporating and cooling the room air, the air is sucked into the compressor (21) through the accumulator (25).

With the above operation, the indoor cooling operation using the cold heat of the ice stored in the heat storage tank (31) is performed.

-Normal Heating Operation- In this operation mode, the water circulation circuit (30) is not operated, and only the refrigerant circulation circuit (20) is operated.

In this operation mode, the four-way switching valve (22) is switched to the broken line in FIG. 1, the outdoor electric expansion valve (EV-1) is controlled to a predetermined opening, and the indoor electric expansion valve (EV-2) is controlled. Is fully opened, and the heat storage electric expansion valve (EV-3) is controlled to be fully closed. On the other hand, each solenoid valve (SV-1, SV-2, SV-3) is closed.

In this state, the refrigerant discharged from the compressor (21) flows into the indoor heat exchanger (24), exchanges heat with the indoor air, condenses, and heats the indoor air. After that, this refrigerant is decompressed by the outdoor electric expansion valve (EV-1),
In (23), heat exchange with the outside air evaporates. Thereafter, the refrigerant is sucked into the compressor (21) via the accumulator (25). The room is heated by such a circulation operation of the refrigerant.

The operation of the regenerative air conditioner (10) has been described above.

As described above, according to the configuration of the present embodiment, each of the flow paths (A, B) inside the subcooling heat exchanger (50) has a uniform cross-sectional shape over its extending direction. With this configuration, the refrigerant and water flowing through each flow path (A, B) both flow in a state of small turbulence, and it is possible to avoid the operation of eliminating supercooling due to the supercooled water flowing in a state of large turbulence. An operation of generating cooling water can be performed.

If freezing occurs in a part of the water flow path (B), stress acts on the heat transfer plates (53 to 58) due to volume expansion when water is frozen. Since the flat plate portion (69) of the heat transfer plates (53-58) is set to have a relatively large area, a large elastic deformation region for the above-mentioned stress is secured. Therefore, the heat transfer plate (53 to 5
8) plastic deformation of the supercooled heat exchanger (50) can be prevented. That is, when the freezing occurs, the heat transfer plates (53 to 58) are elastically deformed, and return to the original shape when the freezing is eliminated.

-Modifications- Next, first and second modifications of the above-described first embodiment will be described. Each of the following modifications is a heat transfer plate (53 to
58), and the other configuration and operation are the same as those of the first embodiment. Therefore, only the arrangement of the heat transfer plates (53 to 58) will be described here.

(First Modification) First, a first modification will be described. As shown in FIG. 7, the heat transfer plate (53
The arrangement of the heat transfer plates (53 to 58) is different from that of the first embodiment described above.
The projection directions of (70) are opposite to each other.

That is, while the bent portion (70) of the first heat transfer plate (53) located at the uppermost portion in FIG. 7 projects downward, the second heat transfer plate located below the bent portion (70). The projecting direction of the bent portion (70) of (54) is upward. A water flow path (B) is formed between the two heat transfer plates (53, 54). In this manner, the heat transfer plates (53 to 58) are so arranged that the protruding directions of the bent portions (70) are alternately reversed.
Is set.

By setting the arrangement of the heat transfer plates (53 to 58) in this manner, the projecting side of the bent portion (70) always faces the water flow path (B). In other words, this water flow passage
(B) is formed by the flat plate portion (69) of each heat transfer plate (53-58) and the projecting side of the bent portion (70), and has a substantially rectangular shape (FIG. 7).
(A substantially parallelogram shape).

Therefore, in the water flow path (B), there is almost no portion where water stays, and the presence of the staying portion causes the water to be locally cooled and the supercooling to be eliminated. Can be avoided.

(Second Modification) Next, a second modification will be described. As shown in FIG. 8, the heat transfer plate (80,
80,…) are corrugated. That is, each of the heat transfer plates (80, 80,...) Has a first curved portion (81) curved so as to bulge in one direction (upward in FIG. 9) and another direction (FIG. 9).
The second curved portion curved so as to bulge downward)
(82) are alternately formed in a corrugated shape, and the first curved portion (81) of the heat transfer plates (80, 80) adjacent to each other is formed.
And the second curved portion (82) are opposed to each other, and their contact portions are brazed. As a result, each heat transfer plate (8
0,80,...) Are formed between the fluid flow paths (A, B).

With such a configuration, also in this example, each of the flow paths (A, B) is formed to have a uniform cross-sectional shape in the direction of extension, and each of the flow paths (A, B) The refrigerant and water flowing through both flow in a state of small turbulence. Therefore, generation of freezing inside the subcooling heat exchanger (50) can be avoided, and a stable operation of generating supercooled water can be performed.

(Second Embodiment) Next, a second embodiment of the present invention will be described. This embodiment is also a modification of the heat transfer plate, and the other configuration and operation are the same as those of the above-described first embodiment. Therefore, only the configuration of the heat transfer plate will be described here.

As shown in FIG. 10, the heat exchanger (5
The heat transfer plates (80, 80,...) Constituting the (0) are formed in the same waveform as in the above-described second modification.

In the portion of the first curved portion (81) and the second curved portion (82) facing each other, which faces the water flow path (B), the curved portions (81, 82) are joined to each other. On the other hand, in the portion facing the flow path (A) of the refrigerant, a gap (S) is intermittently formed between the curved portions (81, 82). Specifically, the first curved portion (81) and the second curved portion facing the refrigerant flow path
In (82), portions brazed to each other and portions arranged so as to have a predetermined interval (S) without being brazed are alternately arranged in the horizontal direction. In other words, the refrigerant flow path (A) has a large passage cross-sectional area, and the water flow path (A)
(B) is formed so as to have a smaller passage cross-sectional area than the coolant passage (A), and these are arranged adjacent to each other.

According to such a configuration, the flow path of the water
Even if freezing occurs in (B) and a large stress acts on the heat transfer plates (80, 80,…) due to its volume expansion, the curved portion of the portion on which the stress is acting is adjacent to the adjacent heat transfer plate. Not joined to (80). For this reason, the elastic deformation region due to this stress is enlarged, and the heat transfer plate (80) can be prevented from being damaged by this stress.

FIG. 11 shows a heat transfer plate.
It is a modification of the joining position between (80, 80). As shown in this figure, the first curved portion (81) and the second curved portion facing the flow path (A) of the refrigerant.
(82) is to arrange the parts brazed to each other and the parts arranged so as to have a predetermined interval without being brazed, and two non-brazed parts between the brazed parts. Have been placed. Also in this case, the same effect as described above can be exerted, and damage to the heat transfer plate (80) can be avoided.

In this embodiment, a portion which is not brazed is provided at a portion facing the flow path (A) of the refrigerant. However, if the pressure in the flow path of the refrigerant can be sufficiently reduced, the flow of the water can be reduced. Road
A portion that is not brazed may be provided in a portion facing (B). Also, in particular, when the present invention is applied to a heat exchanger that performs heat exchange between water and brine, the internal pressure of the flow path does not increase significantly, so that a portion that is not brazed can be arbitrarily set.

Further, in each of the above-described embodiments, the periphery of the opening for flowing the refrigerant and water in each heat transfer plate and the peripheral portion of the plate are sealed by brazing, but are sealed by welding or gasket. May be applied.

In each embodiment, each heat transfer plate (53
Each of the channels (A, B) was formed by brazing the protruding portions (70), (81, 82) of (-58) and (80), but these portions were simply brought into contact with each other. Is also good.

[0086]

As described above, according to the present invention, the following effects are exhibited. According to the first and second aspects of the present invention, the fluid flowing between the heat transfer plates is caused to flow through the plate-type heat exchanger in a state of small turbulence, so that the fluid is cooled to a supercooled state. Even when a heat exchanger is used, it is possible to avoid that supercooling is eliminated by stirring the supercooled fluid. For this reason, freezing of the heat exchanger is avoided. In particular, when the plate-type heat exchanger is applied to an apparatus that performs an ice making operation using a supercooling elimination operation, this plate type The ice making operation can be favorably performed while maintaining the original advantage of the mold heat exchanger, that is, maintaining compactness and high efficiency.

According to the third aspect of the present invention, the configuration of the heat transfer plate can be specifically obtained, and the freezing of the heat exchanger can be avoided similarly to the effect according to the first aspect of the present invention. can do. Further, even if a part of the fluid passage is frozen, even if a stress acts on the heat transfer plate due to volume expansion of the fluid, the flat portion of the heat transfer plate is set to a relatively large area. By doing so, a large elastic deformation region for this stress can be secured. As a result, plastic deformation of the heat transfer plate can be avoided, and reliability of the heat exchanger can be improved.

According to the fourth aspect of the invention, since the projecting side of the flow path forming portion is located in the water-side passage, the cross-sectional shape of the water-side passage can be set to a relatively simple shape such as a rectangular shape. And Therefore, it is possible to prevent the cross section from having a complicated shape. Therefore, the portion of the water-side passage where water easily stays can be reduced, and the operation of eliminating supercooling due to local cooling due to the stay of water can be avoided, and the prevention of freezing of the heat exchanger can be further ensured. Can be done.

According to the fifth to seventh aspects of the present invention, when the fluid in the second passage portion having a smaller passage cross-sectional area out of the fluid flowing through each passage portion becomes iced, the second passage portion is constituted. The first passage adjacent to the second passage portion so as to secure a large elastically deformable region for the stress acting on the heat transfer plate.
The cross-sectional area of the passage was set large. For this reason, plastic deformation of the heat transfer plate can be avoided, and this can also improve the reliability of the heat exchanger.

According to the eighth aspect of the present invention, the heat transfer plate is corrugated, and in the portion facing the fluid passage of the second fluid, the curved portions are joined to each other, while the portion facing the fluid passage of the first fluid. In, a gap was formed between the curved portions. With this. A specific configuration for forming each passage is obtained, and the practicality of the plate heat exchanger can be improved.

According to the ninth aspect of the present invention, the fluid for heat exchange in the plate heat exchanger is set to a refrigerant and water. By these specific items, the fluid flowing through each passage can be embodied. In particular, the present plate-type heat exchanger is used in an apparatus that once cools water to a supercooled state and then cancels the supercooling to perform an ice making operation. When a vessel is applied, the ice making operation can be performed favorably.

[Brief description of the drawings]

FIG. 1 is a diagram showing a refrigerant circulation circuit and a water circulation circuit of a regenerative air conditioner.

FIG. 2 is a diagram showing a water circulation circuit.

FIG. 3 is an exploded perspective view of the plate heat exchanger.

FIG. 4 is a cross-sectional view showing an arrangement state of a heat transfer plate.

FIG. 5 is a circuit diagram of a regenerative air conditioner showing a refrigerant circulation operation during a cold heat storage operation.

FIG. 6 is a circuit diagram of the regenerative air conditioner showing a refrigerant circulation operation during a cold storage use operation.

FIG. 7 is a diagram corresponding to FIG. 4 in a first modified example.

FIG. 8 is a perspective view showing an arrangement state of a heat transfer plate in a second modified example.

FIG. 9 is a view showing a fluid passage in a second modified example.

FIG. 10 is a diagram corresponding to FIG. 9 in a second embodiment.

FIG. 11 is a diagram corresponding to FIG. 9 in a modification of the second embodiment.

[Explanation of symbols]

 (50) Subcooling heat exchanger (plate type heat exchanger) (53 to 58) Heat transfer plate (69) Flat plate (70) Bend (passage forming part) (A) Refrigerant flow path (B) Water flow path

Claims (9)

[Claims] A plurality of heat transfer plates (53-58) are superimposed to form a fluid passage (A, A) between the heat transfer plates (53-58).
B) is formed, and fluids flowing in the fluid passages (A, B) adjacent to each other exchange heat through the heat transfer plates (53 to 58). A plate-type heat exchanger characterized in that at least one of the flowing fluid passages (A, B) has a fluid passage (B) having a uniform cross-sectional shape throughout the flow direction thereof. vessel. 2. The plate heat exchanger according to claim 1, wherein the first fluid and the second fluid are provided in the fluid passages (A, B) adjacent to each other.
Fluids are respectively circulated, and the second fluid is cooled to a supercooled state by heat exchange between the two fluids. The fluid passage (B) of the second fluid extends throughout the fluid flow direction. A plate-type heat exchanger characterized by having a uniform cross-sectional shape. 3. The plate type heat exchanger according to claim 1, wherein the heat transfer plates (53-58) include a flat plate portion (69) and a flat plate portion (69) of an adjacent heat transfer plate (53-58). A passage forming portion (70, 7
0,…)). 4. The plate type heat exchanger according to claim 3, wherein the refrigerant and the water circulate in the fluid passages (A, B) adjacent to each other, and the water exchanges by the heat exchange between the two. It is configured to cool to a cooling state, and the passage forming portions (70, 70, ...) of the heat transfer plates (53 to 58)
A part of the plates (53-58) is bent so as to protrude in one direction in the plate thickness direction and is integrally formed with the flat plate portion (69). The protruding side is located in the water side passage (B), and the flat part (69) of the adjacent heat transfer plate (53-58)
A plate-type heat exchanger, which is in contact with a plate. 5. A plurality of heat transfer plates (80, 80,...) Are superimposed and a fluid passage is provided between the heat transfer plates (80, 80,...).
(A, B) are formed, and the fluids flowing in the fluid passages (A, B) adjacent to each other exchange heat with each other via heat transfer plates (80, 80,...). The passages (A, B) include a first passage portion (A) having a larger passage cross-sectional area, and a second passage portion (B) having a smaller passage cross-sectional area than the first passage portion (A). And the first
A plate-type heat exchanger, wherein the passage (A) and the second passage (B) are arranged adjacent to each other. 6. The plate type heat exchanger according to claim 5, wherein the first passage portion (A) and the second passage portion (B) are formed to have a uniform cross-sectional shape throughout the flow direction. A plate-type heat exchanger. 7. The plate heat exchanger according to claim 5, wherein the fluid passages (A, B) adjacent to each other include a first fluid and a second fluid.
Fluids are circulated respectively, and heat exchange between the two fluids cools the second fluid to a supercooled state. The first fluid passage of the first fluid has a large passage cross-sectional area. (A), and the fluid passage for the second fluid is provided with a second passage (B) having a smaller passage cross-sectional area than the first passage (A). Plate heat exchanger. 8. The plate heat exchanger according to claim 5, wherein the first heat transfer plate is curved so as to bulge in one direction in the thickness direction. The curved portions (81, 81,...) And the second curved portions (82, 82,...) That are curved so as to bulge in the other direction are formed in a wave shape alternately formed, and are adjacent to each other. First curved portion between heat transfer plates (80,80)
(81, 81, ...) and the second curved portion (82, 82, ...) are opposed to each other, and a fluid flow path (A, B) is formed between the two plates (80, 80). The first fluid and the second fluid are provided in the fluid passages (A, B) adjacent to each other.
The fluids are respectively circulated, and are configured to cool the second fluid to a supercooled state by heat exchange between the two fluids. The first curved portions (81, 81,...) And the Part (82,
82,...), The curved portions (81, 82) are in contact with each other at the portion facing the fluid passage (B) of the second fluid, while the portion facing the fluid passage (A) of the first fluid. In the plate heat exchanger, a gap is formed between the curved portions (81, 82). 9. The plate heat exchanger according to claim 7, wherein the first fluid is a refrigerant that exchanges heat with the second fluid, and the second fluid is water. Plate heat exchanger.