JPH11173770A - Plate type heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize a subcooling state by correcting an irregular temperature distribution of a water due to a drift of a refrigerant in a plate type heat exchanger for generating a subcooled water by heat exchanging the water with the refrigerant. SOLUTION: A heat transfer surface 81a made of a waveshape state is formed between a third opening 75a in which a water flows and a fourth opening 76a in which the water discharges. A first opening 73a in which a refrigerant flows is provided at a position of a center of a heat transfer plate P1 above the opening 75a at a heat transfer surface 81a. a refrigerant input part 57a made of a protruding sealing part 58a and a flat part 59a is provided around the opening 73a. The plates P1 are laminated, brought into contact with the part 58a, and a refrigerant inlet having a small opening area and partitioned by the part 58a and the flat part is formed to open from the center of the opening 73a obliquely downward.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plate heat exchanger, and more particularly, to a measure for preventing refrigerant drift.

[0002]

2. Description of the Related Art Conventionally, various heat exchangers have been used in air conditioners, refrigeration units, refrigeration units, and the like. Among those heat exchangers, the plate heat exchanger is
It is known as a compact heat exchanger having a large heat transfer rate.

As shown in FIG. 10, a plate heat exchanger is constituted by stacking a plurality of heat transfer plates (P, P,...) Between two frames (f1) and (f2). ing.

[0004] Each heat transfer plate (P) is made of a metal flat plate, and when laminated, the peripheral edges of the heat transfer plates come into contact with each other so that fluid flow paths (A, B, A) are formed between the heat transfer plates. , B,...) Are formed, and the contact portions are joined by brazing to be integrally formed.

Openings (a, b, c, d) are provided at the four corners of the heat transfer plate (P), and seal portions (e) are provided around the openings (a, b, c, d). By providing the one flow passage
Inflow channel (A1) and outflow channel (A2) communicating only with (A), and inflow channel (B1) and outflow channel (B2) communicating only with the other flow channel (B)
Are formed. In FIG. 10, one fluid flows through the flow passage (A) as shown by the solid arrow, and the other fluid flows through the flow passage (B) as shown by the dashed arrow. , (B) exchange heat with each other.

By the way, for example, Japanese Patent Application Laid-Open No. 4-251177
As disclosed in Japanese Unexamined Patent Application Publication No. 2002-125, a so-called dynamic ice storage type air conditioner is conventionally used in view of reducing the power demand at the peak of the cooling load and expanding the power demand at the off-peak time. Have been.
In this type of air conditioner, slurry-like ice is generated and stored in a heat storage tank at the time of a cooling load off-peak, and this ice is used as a cooling heat source at the time of a cooling load peak.

[0007] Such slurry ice is generated by eliminating the supercooled state of the supercooled water. In general,
The supercooled water is generated by cooling low-temperature water using latent heat of vaporization of the refrigerant flowing through the refrigerant circuit.

[0008]

When the plate heat exchanger is used as an evaporator (supercooling heat exchanger) for generating supercooled water in the air conditioner, the refrigerant and water are transferred to the heat transfer plate (supercooled heat exchanger). It flows through the flow passage formed by P) and performs heat exchange. However, as shown in FIG.
Inlet (a), (c) and outlet (b), (d)
Are provided at the four corners of the heat transfer plate (P), so that the flow velocity of the fluid in each flow passage is not uniform in the width direction of the flow passage, resulting in a drift of the fluid.

[0009] In the flow path of one fluid, a dead water zone where the one fluid does not flow much is generated around the inlet and the outlet of the other fluid. This also causes a drift. Then, due to the above-described drift of the fluid, the following problem occurs.

That is, when the refrigerant drifts, the amount of heat exchange between the refrigerant and water greatly differs from one region to another. For example, the water in the region adjacent to the region where the flow rate of the refrigerant is high is more likely to be cooled than the water in the region adjacent to the region where the flow rate of the refrigerant is low,
Lower temperature. As a result, for example, as shown in FIG. 11, the temperature distribution of water becomes uneven in the width direction of the flow path.

When the temperature of the supercooled water falls below a certain limit temperature, the supercooled state is eliminated. Further, the portion that has been frozen by the supercooled state being eliminated becomes seed ice, which is a factor for eliminating the supercooled state of other supercooled water. Therefore, in order to maintain the supercooled state of the supercooled water, it is necessary to maintain all the regions at a temperature higher than the limit temperature.

On the other hand, in order to efficiently produce slurry ice, it is desirable to make the average temperature of the supercooled water as low as possible. Therefore, in order to efficiently generate the supercooled water while maintaining the supercooled state, it is preferable to equalize the temperature of the supercooled water in the heat exchanger. For example, when generating supercooled water having an average temperature of −3 ° C.,
It is more preferable that all regions have a uniform state of −3 ° C. than a state where the temperature distribution is non-uniform such that the region has a region of 4 ° C. or less. This is because, assuming that the limit temperature is −4 ° C., in such a non-uniform state, icing occurs in a region of −4 ° C. or less.

However, as described above, in the conventional plate heat exchanger, due to the drift of the fluid flowing through each flow path, the flow rate in FIG.
As shown in FIG. 1, the temperature of the supercooled water was not uniform.
Therefore, in order to prevent the flow path from being blocked due to the elimination of the supercooling, the temperature of the lowest temperature region of the supercooling water needs to be higher than the above-mentioned limit temperature. As a result, the average temperature of the supercooled water could not be lowered, and there was a limit to improving the efficiency of producing slurry ice.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to correct the non-uniformity of the temperature distribution of the heat medium due to the drift of the refrigerant and to reduce the supercooled state of the heat medium. It is to stabilize.

[0015]

In order to achieve the above object, the present invention suppresses the drift of the refrigerant by changing the position and shape of the refrigerant inlet.

Specifically, the solution of the first invention is to provide a heat transfer plate (P1) provided with heat transfer surfaces (81a, 81b) for disturbing the refrigerant and the heat medium to promote heat exchange. , P2) are laminated, and a refrigerant flow path (61) or a heat medium flow path (62) is formed on both sides of each heat transfer plate (P1, P2).
In the plate type heat exchanger for exchanging heat between the refrigerant flowing through the heat medium (61) and the heat medium flowing through the heat medium flow passage (62) through the heat transfer plates (P1, P2), the heat transfer plates (P1, P2 The heat transfer surfaces (81a, 81b) pass through the heat transfer plates (P1, P2) and allow the refrigerant to flow from the refrigerant inlet pipe (53) to the refrigerant flow passages (6, 8).
Openings (73a, 7a) for forming a refrigerant inflow space (63) leading to 1)
3b) has been established.

As a result, the refrigerant flows through the refrigerant flow passage (61), while the heat medium flows through the heat medium flow passage (62), and the refrigerant and the heat medium exchange heat with each other. At this time, the refrigerant flows in from the refrigerant inlet pipe (53), passes through the refrigerant inflow space (63), and then flows into the refrigerant flow passage (61). The refrigerant that has flowed into the refrigerant flow passage (61) is quickly dispersed because the flow is disturbed by the heat transfer surfaces (81a, 81b) immediately after the flow. Therefore, the refrigerant flow passage
The drift of the refrigerant in (61) is suppressed.

Further, the solution taken by the second invention is that, in addition to the first invention, the openings (73a, 73b) are provided in the refrigerant flow passage (61) in the heat transfer plates (P1, P2). It is provided at the center in the direction orthogonal to the flow direction.

Thus, since the refrigerant flows into the refrigerant flow passage (61) from the central portion, it is easy to flow uniformly in the refrigerant flow passage (61). Therefore, the drift of the refrigerant in the refrigerant flow passage (61) is further suppressed.

The solution taken by the third invention is as follows.
In addition to the invention, the refrigerant inflow space (63) and each refrigerant flow passage (61)
Means that they are connected to each other by the refrigerant inlets (60, 60) whose opening area is smaller than the area obtained by multiplying the distance between the heat transfer plates (P1, P2) and the peripheral length of the openings (73a, 73b). It was done.

As a result, the refrigerant flowing into the refrigerant flow passage (61) from the refrigerant inflow space (63) passes through the refrigerant inlet (60) having a small opening area, and is accelerated at the refrigerant inlet (60). Then, the refrigerant flows vigorously into the refrigerant flow passage (61). Therefore, immediately after the inflow, the refrigerant is widely dispersed in the refrigerant flow passage (61), and the drift of the refrigerant is further suppressed.

The solution taken by the fourth invention is the third solution.
In addition to the invention of the above, the opening in each heat transfer plate (P1, P2)
(73a, 73b) around the adjacent heat transfer plates (P1, P2)
And a flat portion (93) for forming a predetermined interval that connects the refrigerant inflow space (63) and the refrigerant flow passage (61), and a flat portion (P1 and P2) in adjacent heat transfer plates (P1, P2). 59a, 59b) projecting toward the refrigerant flow passage (61) and abutting therethrough to partially prevent the refrigerant from flowing from the refrigerant inflow space (63) into the refrigerant flow passage (61). (58a, 58b) are provided,
The coolant inlets (60, 60) are connected to the flat part (93) and the seal part (58).
a, 58b).

As a result, the refrigerant in the refrigerant inflow space (63) passes through the inlet (60) defined by the seal portions (58a, 58b) and the flat portion (93), and the refrigerant flow passage (61) Rushed into. Thus, the drift of the refrigerant is suppressed by the simple configuration.

[0024] The solution means adopted by the fifth invention is the above-mentioned third means.
Alternatively, in addition to the fourth aspect, the openings (73a, 73b) are provided below the heat transfer plates (P1, P2), and the refrigerant outlets ( 74a, 74b) are formed, and the refrigerant inflow port is configured such that two flow ports (60, 60) facing obliquely downward from the center of the openings (73a, 73b) are provided in a C-shape. It was done.

As a result, the refrigerant in the refrigerant inflow space (63) flows obliquely downward from the center of the opening (73a, 73b) to the refrigerant flow passage (61) through the circulation port (60, 60). Inflow. The refrigerant that has flowed obliquely downward into the refrigerant flow path (61) is dispersed over a wide range of the refrigerant flow path (61) by being affected by the main flow flowing upward in the refrigerant flow path (61). Therefore, the drift of the refrigerant is further suppressed.

The solution means adopted by the sixth invention is the first means described above.
In addition to the fifth aspect, the heat medium is water, the heat medium flow passage is a water flow passage (62), while the refrigerant flow passage (61) is a refrigerant inlet pipe (53) and a refrigerant outlet pipe (54). Through the refrigerant circuit (20)
And a water circulation passage (62) having a heat storage tank (31) through a water inlet pipe (55) and a water outlet pipe (56).
0), the refrigerant flowing from the refrigerant inlet pipe (53) evaporates in the refrigerant flow passage (61) and flows out to the refrigerant outlet pipe (54), while the water flowing from the water inlet pipe (55) is In the water flow passage (62), the refrigerant is cooled by the refrigerant to be in a supercooled state, flows out of the water outlet pipe (56), is dissolved in the supercooled state, is frozen, and is stored in the heat storage tank (31). It is assumed that it is constituted.

As a result, the plate heat exchanger is used as a supercooling heat exchanger for generating supercooled water. Then, by suppressing the drift of the refrigerant, the water in the water flow path (62) is cooled substantially uniformly in the width direction of the flow path. Therefore, the temperature distribution of the water in the refrigerant flow passage (61) becomes uniform in a direction orthogonal to the flowing direction, and the supercooled state of the water is stabilized. Therefore, the degree of supercooling of water can be stably increased, and freezing in the heat exchanger can be prevented.

The solution taken by the seventh invention is the sixth solution.
In addition to the above invention, the refrigerant is a non-azeotropic mixed refrigerant.

As a result, the temperature of the non-azeotropic refrigerant mixture rises during evaporation, and the non-azeotropic refrigerant is easily affected by the drift, so that the effect of suppressing the drift is more remarkably exhibited.

[0030]

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

<Embodiment 1> As shown in FIG. 1, an air conditioner (10) equipped with a plate heat exchanger (50) of Embodiment 1 comprises a refrigerant circulation circuit (20) and a water circulation circuit (30). ).

The refrigerant circuit (20) includes a compressor (21), a four-way switching valve (22), an outdoor heat exchanger (23), an outdoor electric expansion valve (EV-1),
An indoor electric expansion valve (EV-2), an indoor heat exchanger (24), and an accumulator (25) are provided with a reversible operable main refrigerant circuit (27) configured by being connected by a refrigerant pipe (26). I have. Further, the refrigerant circulation circuit (20) is provided with a heat storage refrigerant circuit (2a), a seed ice circuit (2b), and a hot gas circuit (2c).

This refrigerant circuit (20) is filled with R407C which is a non-azeotropic refrigerant mixture. Therefore, in a subcooling heat exchanger (50) described later, water and R407C exchange heat, and the water is cooled to a supercooled state.

The heat storage refrigerant circuit (2a) is a circuit in which the refrigerant circulates during a cold heat storage operation described later, and has one end connected to the main refrigerant circuit (2a).
The other end is connected between the outdoor heat exchanger (23) of 7) and the outdoor electric expansion valve (EV-1), and the other end is connected between the four-way switching valve (22) and the accumulator (25). The heat storage refrigerant circuit (2a) includes a first solenoid valve (SV-1), a preheater (11), a heat storage electric expansion valve (EV-3), and a subcooling heat exchanger (50 ), And second
The solenoid valve (SV-2) is provided in order from the one end to the other end.

The seed ice circuit (2b) is a circuit for generating seed ice in the water circulation circuit (30). One end of the seed ice circuit (2b) is supercooled with the heat storage electric expansion valve (EV-3) in the heat storage refrigerant circuit (2a). The other end is connected between the subcooling heat exchanger (50) and the second solenoid valve (SV-2) between the heat exchanger (50). In the seed ice circuit (2b), a capillary tube (CP) and a seed ice generator (13) are provided in order from one end to the other end.

The hot gas circuit (2c) supplies a refrigerant discharged from the compressor (21) to the subcooling heat exchanger (50) during a cooling operation using ice stored in the heat storage tank (31). One end is connected to the discharge side of the compressor (21), and the other end is connected between the second solenoid valve (SV-2) and the supercooling heat exchanger (50) in the heat storage refrigerant circuit (2a). , A third solenoid valve (SV-3).

The configuration of the refrigerant circuit (20) has been described above.

On the other hand, as shown in FIG. 2, the water circulation circuit (30) comprises a heat storage tank (31), a pump (32), a preheater (11), and a mixer (3).
3), a supercooling heat exchanger (50), a seed ice generator (13), and a supercooling canceller (34) are sequentially connected by a water pipe (35).

The preheater (11) heats the ice water flowing from the heat storage tank (31) by the refrigerant flowing through the refrigerant circuit (20) and melts the ice chips flowing through the water pipe (35). It is. The mixer (33) stirs the water and ice heated by the preheater (11) to promote melting of the ice. The seed ice generator (13) cools part of the water flowing through the water pipe (35) with the refrigerant flowing through the refrigerant circulation circuit (20) and turns it into seed ice toward the supercooling canceller (34). Supply. The supercooling canceller (34) agitates the seed ice generated by the seed ice generator (13) and the supercooled water generated by the supercooled heat exchanger (50) to eliminate the supercooled state. I do.

As described above, the supercooling heat exchanger (50) composed of the plate heat exchanger of the first embodiment is provided with the refrigerant circulation circuit (20).
The heat exchange is performed between the refrigerant flowing through the water and the water flowing through the water circulation circuit (30), and the water is cooled to a supercooled state during the cold storage operation.

-Configuration of the subcooling heat exchanger (50)-As shown in Fig. 3, the subcooling heat exchanger (50) is composed of two types of transmissions, a first plate (P1) and a second plate (P2). Heat plates are alternately stacked, and they are integrally joined by brazing.

In FIG. 3, the plate located on the most front side includes a refrigerant inlet pipe (53), a refrigerant outlet pipe (54), and a water inlet pipe (5).
5) and the water outlet pipe (56) are joined. The water inlet pipe (55) and the water outlet pipe (56) are provided at the center of the heat transfer plate in the width direction (left-right direction shown in FIG. 3), and the water inlet pipe (55) is provided at the lower end of the plate and the water outlet. The tubes (56) are respectively joined to the upper ends of the plates. The refrigerant inlet pipe (53) is joined above the water inlet pipe (55) and at the center in the width direction of the heat transfer plate, and the refrigerant outlet pipe (54) is below the water outlet pipe (56) for heat transfer. It is joined to the end in the width direction of the plate (the right end in FIG. 3). Refrigerant inlet pipe (53), refrigerant outlet pipe (54), water inlet pipe
(55), the water outlet pipe (56) is a refrigerant inflow space to be described later, respectively.
(63), refrigerant outflow space (64), water inflow space (65), water outflow space
(66).

Both the first plate (P1) and the second plate (P2) have a refrigerant inlet pipe (53), a refrigerant outlet pipe (54), and a water inlet pipe (5).
5) At the position corresponding to the water outlet pipe (56),
(73a), (73b), second openings (74a), (74b), third openings (75a),
(75b), and fourth openings (76a) and (76b) are provided. Then, the plurality of first plates (P1) and the second plates (P2) are alternately stacked to form a refrigerant inflow space (63) composed of a cylindrical space defined by the first openings (73a) and (73b). ),
A coolant outflow space (64) consisting of a cylindrical space defined by the second openings (74a) and (74b), and a water inflow space consisting of a substantially rectangular parallelepiped space defined by the third openings (75a) and (75b) (6
5), a water outflow space (66) composed of a substantially rectangular parallelepiped space defined by the fourth openings (76a) and (76b) is formed.

Next, the configuration of the heat transfer plates (P1) and (P2) will be described. Both plates (P1) and (P2) are made of a flat plate made of metal (for example, stainless steel), and have a wave-shaped heat transfer surface (81a), (82a), which will be described later, and a convex portion that maintains a space between the plates.
(68a), (69a), (77a), etc. are formed by press working. The edges of both plates (P1) and (P2) are
1) and (P2) are entirely bent slightly so that the peripheral portions thereof overlap each other to form the side surface of the heat exchanger when they are stacked. In other words, the bent peripheral portions form side surfaces of the heat exchanger by overlapping.

FIG. 4 shows the front side of the first plate (P1), and FIG. 5 shows the front side of the second plate (P2). Both plates (P
The peripheral portions of 1) and (P2) are bent from the front side to the back side. 1st plate (P1) and 2nd plate (P2)
Are stacked such that one front side faces the other back side. Between the front side of the first plate (P1) and the back side of the second plate (P2), a refrigerant flow passage (61) through which the refrigerant flows is formed. On the other hand, the back side of the first plate (P1) and the second plate (P2)
A water flow passage (62) through which water flows is formed between the front side and the front side.

As shown in FIGS. 4 and 5, the first plate
(P1) and the second plate (P2) have a substantially rectangular fourth
Openings (76a) and (76b) have a substantially rectangular third opening (75a) at the lower end.
(75b) is formed. The fourth openings (76a) and (76b) and the third openings (75a) and (75b) have a horizontal length of the heat transfer plate (P
1) and (P2) are formed to be slightly shorter than the width, and the length in the vertical direction is formed to be substantially equal to the diameter of the water outlet pipe (56) and the water inlet pipe (55). That is, the fourth openings (76a), (7
6b) and the third openings (75a), (75b) are the heat transfer plates (P1),
The opening area is formed as large as possible according to the width of (P2) and the diameters of the water outlet pipe (56) and the water inlet pipe (55). Also, at the right end of the plate, the fourth opening (76a),
Below (76b), circular second openings (74a) and (74b) are formed. Above the third openings (75a) and (75b) and in the center in the width direction of the plate, a circular First openings (73a) and (73b) are formed. The first openings (73a), (73b) and the second openings (74a), (7
4b) is formed to have the same diameter as the refrigerant inlet pipe (53) and the refrigerant outlet pipe (54), respectively.

Around the first openings (73a) and (73b) of the first plate (P1) and the second plate (P2), a refrigerant inflow portion (57a) for preventing the refrigerant from flowing in the refrigerant flow passage (61) is provided. ) And (57b) are formed. As shown in FIG. 6, the refrigerant inflow portion (57a) of the first plate (P1) has a seal portion (58a) formed in a convex shape from the back side to the front side (front side in FIG. 5), and a flat portion. (Five
9a). On the other hand, the second plate (P2)
The refrigerant inflow portion (57b) includes a seal portion (58b) formed in a convex shape from the front side to the back side, and a flat portion (59b).

The flat portions (59a) and (59b) have first openings (73a) and (73).
(b) is formed in a substantially annular shape concentric with the first openings (73a) and (73b) so as to cover the periphery thereof, and has flat portions (93) and (93) continuous with the first opening (73a). ing. Then, the front side of the seal portion (58a) of the first plate (P1) comes into contact with the back side of the seal portion (58b) of the second plate (P2) and is brazed, so that the flat portions (93), ( 93) (60), (6
0) is formed. In other words, each heat transfer plate (P1),
Around the first openings (73a) and (73b) in (P2), a refrigerant inflow space (63) and a refrigerant flow passage (61) are connected between adjacent heat transfer plates (P1) and (P2). A flat portion (93) for forming such a predetermined interval and adjacent heat transfer plates (P1), (P2)
Of the flat parts (59a) and (59b) in the refrigerant flow passage (61)
Convex seal portions (58a) and (58b) that partially prevent the refrigerant from flowing into the refrigerant flow passage (61) from the refrigerant inflow space (63) by projecting toward and abutting the refrigerant flow. Entrance (60),
(60) is defined by the flat portion (93) and the seal portions (58a, 58b). As shown in FIG. 7, in the present embodiment, since the seal portions (58a) and (58b) adjacent to the flat portion (93) are formed in an arc shape, the refrigerant inlet (60) has a circular cross section. It becomes a communication port.

As shown in FIG. 6, as a feature of the present invention, the refrigerant inlets (60), (60)
The first opening (73a) is provided with a C-shape that opens downward from the center of the first opening (73a) so as to flow obliquely downward from left to right from the (63) toward the refrigerant flow passage (61). Specifically, the first opening (73a),
The horizontal line (N) passing through the center of (73b) and the center axis (M) of the refrigerant inlet (60) are formed at an angle of 22.5 degrees to each other. Also, each refrigerant inlet (60) is connected to the first opening (73a), (7
The openings are smaller than those in 3b). For more information,
The opening area of each refrigerant inlet (60) is equal to the heat transfer plate (P1), (P
2) and the area multiplied by the peripheral length of the first openings (73a) and (73b).

On the other hand, the back side of the flat portion (59a) of the first plate (P1) abuts on the front side of the flat portion (59b) of the second plate (P2) and is brazed to form the first opening (73a). ), (73b)
Is separated from the water flow passage (62), and as a result, the refrigerant inflow space
(63) and a water flow passage (62) are defined.

Further, as a feature of the present invention, the refrigerant inflow portion (5
7a) and (57b) are provided inside the heat transfer surfaces (81a) and (81b). Conversely, around the refrigerant inlets (57a) and (57b),
Heat transfer surfaces (81a) and (81b) are formed. That is, the first openings (73a) and (73b) are provided on the heat transfer surfaces (81a) and (81b).

As shown in FIGS. 4 and 5, the second opening (74
a) and (74b), flat portions (67a) and (67b) covering the periphery of the second openings (74a) and (74b), and approximately semispherical first convex portions (68a) and (6).
8b), and refrigerant outflow portions (70a) and (70b) formed of the second convex portions (69a) and (69b) in a semicircular shape. 1st plate
The first protrusion (68a) and the second protrusion (69a) of (P1) are convex from the back side to the front side, while the second plate (P2)
The first convex portion (68b) and the second convex portion (69b) are convex from the front side to the rear side. When the first plate (P1) and the second plate (P2) are stacked, the first plate (P1)
The front side of the projection (68a) and the first projection (68b) of the second plate (P2)
The back side of the first plate (P1) is brought into contact with the front side of the second protrusion (69a) of the first plate (P1) and the second protrusion (69b) of the second plate (P2). A predetermined distance is maintained between the front side of the plate (P1) and the back side of the second plate (P2), and a flow path from the refrigerant flow passage (61) to the refrigerant outflow space (64) is secured. On the other hand, the flat portion (59a) of the first plate (P1)
Of the second plate (P2) and the front side of the flat portion (59b) of the second plate (P2) are abutted and brazed so that the second openings (74a), (7
4b) is partitioned from the water flow passage (62), and the refrigerant outflow space (64) and the water flow passage (62) are partitioned.

A flat portion is provided around the third openings (75a) and (75b).
Water inflow portions (71a) and (71b) formed of (72a) and (72b) and a plurality of convex portions (77a) and (77b) are formed. Convex (77a), (77b)
Are provided in a scattered manner so as to surround the third openings (75a) and (75b), and the flat portions (72a) and (72b) have the third openings (75a) and (75b) and the convex portion (77a). , (77b). The convex portion (77a) of the first plate (P1) is convex from the front side to the rear side, while the convex portion (77a) of the second plate (P2) is convex.
(77b) is convex from the back side to the front side. Therefore, when the first plate (P1) and the second plate (P2) are stacked, the front side of the flat portion (72a) of the first plate (P1) and the flat portion (72b) of the second plate (P2) are stacked. The third openings (75a) and (75b) are separated from the refrigerant flow passage (61) by being in contact with the back side and brazing, and the refrigerant flow passage (61) and the water inflow space are separated.
(65). On the other hand, the projections (7
7a) and the front side of the projection (77b) of the second plate (P2) are brought into contact with each other and brazed, so that the first plate (P2)
A predetermined distance is maintained between the back side of 1) and the front side of the second plate (P2), and a flow path from the water inflow space (65) to the water flow passage (62) is secured. That is, water flows into the water flow passage (62) from all around the third openings (75a) and (75b).

Around the fourth openings (76a) and (76b), like the third openings (75a) and (75b), flat portions (78a) and (78b) and a plurality of convex portions (79a) and (79b) Water outflow portions (80a) and (80b) composed of 79b) are formed. The water outlets (80a), (80b) are the water inlets (71a),
(71b), and separates the refrigerant flow passage (61) from the water outflow space (66) and secures a flow path from the water flow passage (62) to the water outflow space (66). ing. Therefore, the water flows out of the water flow passage (62) through the entire periphery of the fourth openings (76a) and (76b), and flows into the water flow passage (62).

Next, the first plate (P1) and the second plate
The heat transfer surfaces (81a) and (81b) of (P2) will be described. Each heat transfer surface
(81a) and (81b) are portions that promote heat exchange by disturbing the refrigerant and the heat medium (water), and have a flat top (solid line in FIGS. 4 and 5) and a bottom. It has a wave shape in which flat valleys (broken lines in FIGS. 4 and 5) are alternately formed. In this wave shape, an upper inclined portion (86) inclined upward as the extension direction of the peak and the valley goes rightward, and a lower inclined portion (87) inclined downward are formed alternately. At the same time as the so-called herringbone shape, the upper sloping part (86) and the lower sloping part (87) are aligned in the longitudinal direction (vertical direction) of the plates (P1) and (P2). It is formed so that it becomes. First plate (P
In the heat transfer surface (81a) of (1) and the heat transfer surface (81b) of the second plate (P2), the extending directions of the peaks and valleys are different from each other. That is, in the first plate (P1), as shown in FIG. 4, the herringbone shape is formed in the order of the upper inclined portion (86) and the lower inclined portion (87) from the left end, while the second plate ( P2)
5, a herringbone shape is formed in the order of the lower inclined portion (87) and the upper inclined portion (86) from the left end.

The heat transfer surfaces (81a) and (81b) will be described in more detail. As shown in FIG. 8, the heat transfer surfaces (81a) of the first plate (P1)
a) is a valley (83) having a predetermined depth and a first peak (8) having a predetermined height.
4) and a second peak portion (85) lower in height than the first peak portion (84). The first mountain part (84) and the second mountain part (85)
They are formed alternately with the valleys (83) interposed therebetween. That is, the wave shape of the heat transfer surface (81a) is the first peak (84) and the valley (8
3), a second peak (85), and a valley (83) are sequentially and repeatedly provided. In the present embodiment, the second peak (85)
Is half the height of the first peak (84).

The heat transfer surface (81b) of the second plate (P2) has a first valley (88) having a predetermined depth and a second valley (89) which is shallower than the first valley (88). ) And a ridge (90) having a predetermined height. The first valleys (88) and the second valleys (89) are formed alternately with the ridges (90) interposed therebetween. In other words, the heat transfer surface (8
The wave shape of 1b) has a first valley (88), a peak (90), and a second valley (8).
9), the ridges (90) are repeatedly provided in order. In the present embodiment, the depth of the second valley (89) is the first valley (89).
It is half the depth of the valley (88).

Then, the first plate (P1) and the second plate
(P2) are alternately laminated, so that the first ridge (84) of the heat transfer surface (81a) and the first valley (88) of the heat transfer surface (81b) abut, while the heat transfer The second valley (89) of the surface (81a) and the second ridge (85) of the heat transfer surface (81b) are separated from each other at a predetermined interval,
A refrigerant flow passage (61) is formed between the front side of the heat transfer surface (81a) and the back side of the heat transfer surface (81b). In addition, the valley of the heat transfer surface (81a) (8
3) and the ridge (90) of the heat transfer surface (81b) abut against the heat transfer surface (81a).
A water flow passage (62) is formed between the back side of the heat transfer surface and the front side of the heat transfer surface (81b).

The first peak portion (84) of the heat transfer surface (81a) and the heat transfer surface (81)
The first valley (88) of b) is joined by brazing. In contrast, the valley (83) of the heat transfer surface (81a) and the heat transfer surface (81a)
The ridge (90) in b) is merely in contact and not joined. That is, when water freezes in the water flow passage (62), the heat transfer plates (P1) and (P2) are deformed so that the valley (83) and the ridge (90) are separated from each other, and Is adapted to absorb the volume expansion.

-Operation- Next, the operation of the air conditioner (10) (cold heat storage operation).
Will be described.

In the cold heat storage operation in which the slurry ice is stored in the heat storage tank (31), as shown in FIG. 1, the four-way switching valve (22) is set to the solid line side, and the heat storage electric expansion valve (EV-3) Is adjusted to a predetermined opening degree, while the other electric expansion valves (EV-1) and (EV-2) are closed. The first and second solenoid valves (SV-1) and (SV-2) are open, and the third solenoid valve (SV-3) is closed.

In this state, in the refrigerant circulation circuit (20), the refrigerant discharged from the compressor (21) circulates as shown by a solid line arrow in FIG. That is, the discharged refrigerant exchanges heat with the outside air in the outdoor heat exchanger (23) to be condensed, and the heat storage electric expansion valve (E
After the pressure is reduced in V-3), the water is exchanged with water in the supercooling heat exchanger (50) to evaporate, and the water is cooled to a supercooled state. Thereafter, the refrigerant is sucked into the compressor (21) via the accumulator (25).

In this operation, a part of the refrigerant is diverted from the downstream side of the heat storage electric expansion valve (EV-3) to the seed ice circuit (2b), and the refrigerant is decompressed by the capillary tube (CP). Is evaporated by the seed ice generator (13), and is sucked into the compressor (21) through the accumulator (25). In this seed ice generator (13),
The refrigerant exchanges heat with the water flowing through the water pipe (35), and the seed ice is transferred to the water pipe.
Generated on the inner wall of (35).

On the other hand, in the water circulation circuit (30), water is circulated by driving the pump (32). As shown in FIG. 2, 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), and reaches a predetermined supercooling state.
Outflow from (50). Then, the supercooled water flowing out of the supercooling heat exchanger (50) is further cooled in the seed ice generator (13) and generates seed ice on the inner wall surface of the water pipe (35). Thereafter, ice nuclei are generated around the seed ice, and the supercooled water containing the ice nuclei is supplied to the supercooling canceller (34). And
In the subcooling canceller (34), the ice nuclei and the supercooled water are agitated, and slurry-like ice for heat storage is generated and collected and stored in the heat storage tank (31).

-Flow of refrigerant and water in subcooling heat exchanger (50)-Next, the flow of refrigerant and water in the subcooling heat exchanger (50) will be described. As shown in FIG. 3, first, the refrigerant flows from the refrigerant inlet pipe (53) into the refrigerant inflow space (63),
The refrigerant flows into the refrigerant flow passage (61) through (60). Then, it flows through the refrigerant flow passage (61), exchanges heat with water in the adjacent water flow passage (62), evaporates, and cools the water. The evaporated refrigerant is
After passing through the refrigerant outflow space (64), it flows out of the subcooling heat exchanger (50) and flows through the refrigerant outlet pipe (54). On the other hand, water is
(55) into the water inflow space (65),
From (65), the water flows into the water passage (62). And the water passage (6
2), is cooled by performing heat exchange with the refrigerant in the adjacent refrigerant flow passage (61), and enters a supercooled state. The water cooled to the supercooled state passes through the water outflow space (66), flows out of the supercooling heat exchanger (50), and flows through the water outlet pipe (56).

Here, as a feature of the present invention, a refrigerant inflow portion
Since (57a) and (57b) are provided inside the heat transfer surfaces (81a) and (81b), the refrigerant inflow space (6
The refrigerant that has flowed out to 3) is the heat transfer surface (81a), (81b)
Is stirred by. Therefore, the state is dispersed immediately after the outflow. In addition, the refrigerant inflow space (63) is
1), (P2) is provided at the center in the width direction, and the refrigerant inflow space (6
3) and the refrigerant inlets (60), (60) that communicate the refrigerant flow passage (61).
Is a small opening and is provided in a C-shape, so that the refrigerant in the refrigerant inflow space (63) accelerates when passing through the refrigerant inflow ports (60), (60), and flows out diagonally right and left downward. The refrigerant flows into the refrigerant flow passage (61) in a more dispersed state. Therefore, the refrigerant flowing through the refrigerant flow passage (61) has a uniform flow without drift.

In the present embodiment, the refrigerant flowing through the supercooling heat exchanger (50) is a non-azeotropic mixed refrigerant. However, the temperature of the non-azeotropic mixed refrigerant increases with evaporation, so that the non-azeotropic mixed refrigerant increases in the heat exchanger. A temperature distribution occurs. However, in the subcooling heat exchanger (50), the refrigerant flows uniformly without any drift, so that the refrigerant temperature distribution in the width direction of the heat transfer plates (P1) and (P2) in the refrigerant flow passage (61) is uniform. Become.

On the other hand, the water inflow space (65) has a heat transfer plate (P
1) and (P2) are provided at the center in the width direction and have a large cross-sectional area.
The flow velocity of the water flowing into the water flow passage (65) decreases, and the flow of the water flowing into the water flow passage (62) becomes smooth. In other words, the water inflow space (6
5) serves as a buffer for the water flow and prevents its drift. Similarly to the water inflow space (65), the water outflow space (66) is provided at the center in the width direction of the heat transfer plates (P1) and (P2), and has a large cross-sectional area. The water flowing through the passage (62) flows almost uniformly over the entire width of the heat transfer plates (P1) and (P2). Then, the supercooled water in each water flow passage (62) flows into the water outlet pipe (56) after being mixed at a reduced flow velocity in the water outflow space (66), so that the supercooled Is less likely to occur.

As a result, both the refrigerant and the water flow uniformly without any drift, and the heat transfer plate (P
The water temperature distribution in the width direction of (1), (P2) becomes uniform.

As described above, the cold heat storage operation using the plate heat exchanger of the first embodiment as the supercooling heat exchanger (50) is performed.

In the air conditioner (10), in addition to the cold storage operation, the four-way switching valve (22) and the solenoid valves (SV-1, SV-
By switching between the SV-2 and the SV-3, etc., it is possible to perform indoor cooling operation using the cold heat of the ice stored in the heat storage tank (31). Further, a normal cooling operation or a normal heating operation in which the room is air-conditioned using only the refrigerant circulation circuit (20) is of course also possible.

According to the present embodiment, in each of the heat transfer plates (P1) and (P2) of the supercooling heat exchanger (50), the first cooling medium inlet space (63) is formed. Since the openings (73a) and (73b) are provided inside the heat transfer surfaces (81a) and (81b), the refrigerant flowing from the refrigerant inflow space (63) into the refrigerant flow passage (61) is Immediately after flowing into 61), it is stirred by the heat transfer surfaces (81a) and (81b), so that it is easily dispersed. As a result, drifting of the refrigerant is suppressed.

Further, since the first openings (73a) and (73b) are formed at the center in the width direction of the plate, the refrigerant flowing from the refrigerant inflow space (63) into the refrigerant flow passage (61) can be moved in the width direction of the plate. As a result, the drift can be effectively prevented.

Further, a refrigerant inflow portion (57) is provided around the first openings (73a) and (73b), and a refrigerant inflow space (63) and a refrigerant flow passage (61) are provided.
Is communicated by the refrigerant inlet (60), which is a small opening, so that the refrigerant vigorously flows from the refrigerant inlet (60) into the refrigerant inflow space (63), and the heat transfer plates (P1), (P2) Widely distributed in the width direction. Therefore, the drift of the refrigerant can be further suppressed.

Further, the refrigerant inlets (60), (60) are connected to the first opening.
(73a), (73b) are composed of two openings, one opening diagonally downward and right from the center of (73b) and the other opening diagonally downward from left, and these openings (60) and (60) are arranged in a C-shape. Therefore, when the refrigerant flows into the refrigerant flow passage (61), it flows diagonally right and left and downward. Therefore, the refrigerant is influenced by the main flow flowing upward in the refrigerant flow passage (61), and as a result, the drift of the refrigerant is more effectively mitigated, and the refrigerant flows through the refrigerant flow passage (61) in a more uniform state. .

In particular, since a non-azeotropic mixed refrigerant is used as the refrigerant, when there is a drift in the refrigerant, the temperature distribution becomes uneven in the width direction of the plate. However, as described above, since the drift of the refrigerant is prevented, the temperature distribution of the refrigerant becomes uniform in the width direction of the plate. Therefore, the effect of preventing drift is more remarkably exhibited.

By preventing the refrigerant from drifting in this manner, the amount of heat exchange increases, and as shown in FIG. 9, the temperature distribution of the water becomes uniform in the width direction of the plate, and the water is supercooled. The state stabilizes. In FIG. 9, illustration of the heat transfer surfaces (81a) and (81b) is omitted.

On the other hand, a third opening forming a water inflow space (65)
(75a), (75b) and the fourth opening (7
Since the heat transfer plates (6a) and (76b) are formed at the center in the width direction of the heat transfer plates (P1) and (P2), the drift of the water flowing through the water flow passage (62) is prevented.

Further, since the third openings (75a) and (75b) are large-area openings, the volume of the water inflow space (65) becomes large. Therefore, the water inflow space (65) serves as a buffer for the water flow, and the flow of the water into the water flow passage (62) becomes smooth.

Further, since the third openings (75a) and (75b) are formed so as to be wide over substantially the entire area in the width direction of the heat transfer plates (P1) and (P2), the water is spread in the width direction of the plates. Flows from the water inflow space (65) into the water flow passage (62). As a result, drifting of water is prevented.

The fourth openings (76a) and (76b) are also connected to the third openings (7
Like (5a) and (75b), the heat transfer plates (P1) and (P2) are formed wide in the width direction and have large openings, so the water inflow space (65) and the water outflow space (66) The flow of the water flowing to becomes smooth.

As described above, since the drift of water is also prevented, the amount of heat exchange is further increased, and the supercooled state of water is further stabilized.

Further, since the fourth openings (76a) and (76b) are large-area openings, the volume of the water outflow space (66) becomes large. Therefore, the supercooled water flowing through each water flow passage (62) joins in the water outflow space (66) at a low flow velocity. Therefore, the supercooled state is unlikely to be eliminated, and freezing in the heat exchanger is prevented.

<Other Embodiments> In the first embodiment, since the first openings (73a) and (73b) are provided at a predetermined distance from the water inflow portions (71a) and (71b), the refrigerant inlet Although (60) is provided obliquely downward, the opening direction of the refrigerant inlet (60) can be changed according to the position of the first opening.

For example, the first opening is the first opening of the first embodiment.
When provided below the openings (73a) and (73b), the refrigerant inlet (60) may be provided horizontally from the center of the first opening. When the first opening is formed at the lowermost end of the heat transfer surfaces (81a) and (81b), the refrigerant inlet (60) may be provided slightly obliquely upward from the center of the first opening. Also in these cases, the drift of the refrigerant is prevented, and the same effect as in the first embodiment can be obtained.

The number of refrigerant inlets (60), (60) is not limited to two, but is three
There may be more than one.

The refrigerant is not limited to the non-azeotropic refrigerant mixture, but may be another refrigerant such as a pseudo-azeotropic refrigerant or a single refrigerant.

The heating medium is not limited to water, and may be any heating medium that can produce a slurry-like icy substance by eliminating a supercooled state, and may be, for example, various aqueous solutions.

[0089]

As described above, according to the first aspect, the opening through which the refrigerant flows is provided on the heat transfer surface.
The flow of the refrigerant flowing into the refrigerant flow passage can be dispersed immediately after the flow, and as a result, the drift of the refrigerant can be suppressed. Therefore, heat exchange between the refrigerant and the heat medium can be performed uniformly, the amount of heat exchange can be increased, and the supercooled state of the heat medium can be stabilized.

According to the second aspect of the present invention, since the refrigerant flows from the central portion of the refrigerant flow passage, the refrigerant can be dispersed over a wide range of the refrigerant flow passage at the time of the flow and can flow uniformly.

According to the third aspect of the present invention, the refrigerant can be accelerated when flowing into the refrigerant flow passage, and can be vigorously flowed into the refrigerant flow passage, so that it can be widely dispersed immediately after the flow. Therefore, it is possible to further suppress the drift of the refrigerant.

According to the fourth aspect, the drift of the refrigerant can be suppressed with a simple and inexpensive configuration.

According to the fifth aspect, since the refrigerant flows obliquely downward into the refrigerant flow path, the refrigerant is dispersed over a wide area of the refrigerant flow path by utilizing the influence of the main flow flowing upward. Becomes possible. Therefore, the drift of the refrigerant can be further suppressed.

According to the sixth aspect of the present invention, by using the supercooled heat exchanger for generating the supercooled water, it is possible to stably generate the supercooled water having a high degree of supercooling.

According to the seventh aspect, the effect of suppressing the drift can be more remarkably exhibited by using the non-azeotropic mixed refrigerant which is easily affected by the drift.

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram and a water circuit diagram of an air conditioner.

FIG. 2 is a water circulation circuit diagram of the air conditioner.

FIG. 3 is a perspective view of a subcooling heat exchanger.

FIG. 4 is a front view of a first plate.

FIG. 5 is a front view of a second plate.

FIG. 6 is a partially enlarged front view of a first plate.

FIG. 7 is a sectional view taken along line XX of FIG. 6;

FIG. 8 is a sectional view of a heat transfer surface of the subcooling heat exchanger.

FIG. 9 is an isotherm diagram of water in a water flow passage.

FIG. 10 is an exploded perspective view of a conventional plate heat exchanger.

FIG. 11 is an isotherm diagram of water in a conventional plate heat exchanger.

[Explanation of symbols]

 (50) Subcooling heat exchanger (53) Refrigerant inlet pipe (54) Refrigerant outlet pipe (55) Water inlet pipe (56) Water outlet pipe (57a), (57b) Refrigerant inflow part (58a), (58b) Seal (59a), (59b) Flat part (61) Refrigerant flow path (62) Water flow path (63) Refrigerant inflow space (64) Refrigerant outflow space (73a), (73b) First opening (81a), (81b) Heat transfer surface (P1), (P2) Heat transfer plate

Claims (7)

[Claims] A heat transfer plate (P) provided with heat transfer surfaces (81a, 81b) for disturbing a refrigerant and a heat medium to promote heat exchange.
1, P2) are laminated, and a refrigerant flow passage (61) or a heat medium flow passage (62) is formed on both sides of each heat transfer plate (P1, P2).
In a plate heat exchanger for exchanging heat between the refrigerant flowing through the refrigerant flow passage (61) and the heat medium flowing through the heat medium flow passage (62) through the heat transfer plates (P1, P2), the heat transfer plates ( The heat transfer surfaces (81a, 81b) of the heat transfer plates (P1, P2) pass through the heat transfer plates (P1, P2) and guide the coolant from the coolant inlet pipe (53) to the coolant flow passage (61). Inflow space
A plate heat exchanger comprising openings (73a, 73b) for forming (63). 2. The plate heat exchanger according to claim 1, wherein the openings (73a, 73b) are formed in a direction orthogonal to a refrigerant flow direction of the refrigerant flow passage (61) in the heat transfer plates (P1, P2). A plate-type heat exchanger provided at a central portion. 3. The plate-type heat exchanger according to claim 1, wherein the refrigerant inflow space (63) and each of the refrigerant flow passages (61) are formed by an interval between the heat transfer plates (P1, P2) and an opening (73a, 73b) a plate-type heat exchanger, which is connected to each other by refrigerant inlets (60, 60) having an opening area smaller than an area multiplied by a peripheral length of the heat exchanger. 4. The plate heat exchanger according to claim 3, wherein the openings (73a, 73b) in each heat transfer plate (P1, P2) are surrounded by adjacent heat transfer plates (P1, P2). A flat portion (93) for forming a predetermined space between the refrigerant inflow space (63) and the refrigerant flow passage (61), and a heat transfer plate (P
Part of the flat part (59a, 59b) in (1, P2) is
1) a convex seal portion (58a, 58b) is provided to partially prevent the inflow of the refrigerant from the refrigerant inflow space (63) into the refrigerant flow passage (61) by projecting toward the side and abutting the refrigerant flow. The inlet (60, 60) is connected to the flat part (93) and the seal part (58).
a, 58b). A plate-type heat exchanger. 5. The plate heat exchanger according to claim 3, wherein the openings (73a, 73b) are provided below the heat transfer plates (P1, P2). Refrigerant outlets (74a, 74b) are formed in the upper part of the heat transfer plates (P1, P2), and the refrigerant inlets are two flow openings (60, 60) facing obliquely downward from the center of the openings (73a, 73b). (60) is provided in the shape of a letter "C". 6. The plate heat exchanger according to claim 1, wherein the heat medium is water, the heat medium flow path is a water flow path, and the refrigerant flow path is 61) is connected to the refrigerant circuit (20) via the refrigerant inlet pipe (53) and the refrigerant outlet pipe (54), and the water flow passage
(62) via the water inlet pipe (55) and the water outlet pipe (56)
The refrigerant flowing from the refrigerant inlet pipe (53) evaporates in the refrigerant flow passage (61) and flows out to the refrigerant outlet pipe (54) while being connected to the water circulation circuit (30) having the water inlet pipe (54). The water flowing in from 55) is cooled by the refrigerant in the water flow passage (62) to be in a supercooled state and flows out of the water outlet pipe (56), and the supercooled state is eliminated and iced,
A plate type heat exchanger configured to be stored in the heat storage tank (31). 7. The plate heat exchanger according to claim 6, wherein the refrigerant is a non-azeotropic mixed refrigerant.