JP4827905B2 - Plate type heat exchanger and air conditioner equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plate heat exchanger capable of suppressing increase of pressure loss of fluid even if a wave angle is increased and a wave pitch is reduced for improving heat transfer. <P>SOLUTION: In the plate heat exchanger 1, a first passage A and a second passage B are formed between a plurality of heat transfer plates 101, 102, and heat exchange is carried out by passing a first fluid and a second fluid through the first and second passages A, B. Heat transfer promoting faces 115, 117 promoting heat exchange are provided on surfaces of the heat transfer plates 101, 102, they are formed by wave parts of alternately repeating ridge parts and valley parts along a height direction of the heat transfer plate, and heights of the wave parts 116, 118 are changed in longitudinal directions of the wave parts 116, 118 such that junction lengths L of the wave parts 116, 118 in joints of the heat transfer plates 101, 102 are maintained at 30% with respect to a width W of the heat transfer plates 101, 102 to adjust the number of the joints of the heat transfer plates 101, 102. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a plate heat exchanger and an air conditioner equipped with the plate heat exchanger.

Conventionally, the plate heat exchanger has a problem that it is difficult to improve heat transfer because the fluid flows in a laminar flow, and the pressure loss increases because the increase in the flow velocity is accompanied by the improvement in heat transfer of the fluid.
In order to solve such a problem, the heat transfer plate having a reduced aspect ratio (ratio of the longitudinal length H to the lateral length W) (see, for example, Patent Document 1), or a wave angle or shape (For example, refer to Patent Document 2).

Japanese Patent No. 3292128 (2nd to 3rd pages, FIG. 5 and FIG. 6) Japanese Patent No. 3049450 (page 3, FIGS. 1 and 2)

However, as in the technique described in Patent Document 1, if the aspect ratio is reduced, the cross-sectional area of the flow path is increased and the flow velocity is reduced, so that the heat exchange efficiency at the same flow rate is poor.
Increasing the wave angle to improve heat transfer increases the brazing area of adjacent plate joints that form the flow path and narrows the flow path, increasing pressure loss and, in addition, joining adjacent plates. Since the points are reduced, the strength is insufficient. In addition, if the wave pitch is reduced in order to increase the joint points of adjacent plates in order to improve the strength, there is a problem that the pressure loss increases due to the increase of the joint points.

  For this reason, the wave angle and shape can be changed as in the technique described in Patent Document 2, but the brazing area of the adjacent plate joint becomes large in the hard notch region where the wave angle is large, and the wave angle In the soft notch region where the diameter is small, the number of joints between adjacent plates increases, so that the pressure loss increases as the strength increases.

  The present invention has been made in order to solve the above-mentioned problems, and in order to improve heat transfer, even if the wave angle is increased and the wave pitch is decreased, the plate type heat that can suppress the increase in the pressure loss of the fluid is achieved. An object is to provide an exchanger and an air conditioner equipped with the exchanger.

In the plate heat exchanger according to the present invention, a first flow path and a second flow path are formed between a plurality of heat transfer plates that are stacked and joined, and the first flow path and the second flow path respectively. A plate-type heat exchanger that circulates between a heat transfer plate through a first fluid and a second fluid, and exchanges heat between the first fluid and the second fluid. A heat transfer promotion surface that disturbs the flow of the two fluids to promote heat exchange, and the heat transfer promotion surface is alternately repeated in the height direction of the heat transfer plate at the peaks and valleys; The corrugation is formed by changing the height of the corrugation in the longitudinal direction of the peak portion, and the joining length of the corrugation at the joint of adjacent heat transfer plates is 30% of the width of the heat transfer plate. The wave portion is formed so as to maintain, and the number of junctions of the heat transfer plate is adjusted.
Moreover, the air conditioner which concerns on this invention mounts said plate type heat exchanger.

According to the plate heat exchanger according to the present invention, the height of the wave portion is set to be long so that the joining length of the wave portion at the joining portion of the adjacent heat transfer plates is maintained at 30% with respect to the width of the heat transfer plate. Since the number of junction points is adjusted by changing the direction, the fluid flow path can be configured with the minimum number of junction points, and while maintaining the same strength as before, the increase in pressure loss is suppressed and heat exchange is performed. The rate can be improved. For this reason, even when the wave angle of the heat transfer plate is set to 70 ° to 80 ° and the wave pitch is set to about 4 mm, an increase in pressure loss can be suppressed and the heat exchange rate can be improved. Moreover, when the width | variety of a heat exchanger plate is made narrow within the range of 4 to 6 aspect ratio, the inlet flow velocity of the fluid which flows in between heat exchanger plates becomes large, and the heat exchange rate between heat exchanger plates further improves.
In this way, heat transfer is good and the increase in pressure loss can be suppressed to a minimum while maintaining strength. Therefore, an inexpensive and reliable plate heat exchanger and an air conditioner equipped with the plate heat exchanger are provided. Obtainable.

Embodiment 1 FIG.
1 is an exploded perspective view schematically showing a plate heat exchanger according to Embodiment 1 of the present invention, FIG. 2 is a side view of the assembled state of FIG. 1, and FIG. 3 is a first reinforcing member of FIG. 4 is a front view of the first heat transfer plate in FIG. 1, FIG. 5 is a front view of the second heat transfer plate in FIG. 1, and FIG. 6 is a second reinforcing side in FIG. It is a front view of a plate.
As shown in FIG. 1, in the plate heat exchanger 1, the two outermost plates, that is, the first reinforcing side plate 2 (see FIG. 3) and the second reinforcing side plate 3 (see FIG. 1). 6)), two kinds of heat transfer plates, that is, the first heat transfer plate 101 (see FIG. 4) and the second heat transfer plate 102 (see FIG. 5) are alternately stacked and brazed. Are joined together. Between the first and second heat transfer plates 101 and 102, a first flow path A in which the first fluid flows and a second flow path B in which the second fluid flows are alternately and repeatedly formed.

  The first and second reinforcing side plates 2 and 3 and the first and second heat transfer plates 101 and 102 are made of a substantially rectangular flat plate made of metal, and at least the aspect ratio of the heat transfer plates 101 and 102 is 4. It is in the range of ~ 6. The aspect ratio is the ratio of the height to the width W of the heat transfer plates 101 and 102. By increasing the aspect ratio to 4 to 6, the increase in pressure loss of the fluid is suppressed and the heat of the plate heat exchanger 1 is increased. Transmission can be improved.

  A first fluid inflow pipe 4 and a first fluid outflow pipe 5 are respectively provided in the lower left part and the upper right part of the first reinforcing side plate 2, and a second fluid is provided in the upper left part and the lower right part, respectively. Inflow pipe 6 and second fluid outflow pipe 7 are provided.

  The first heat transfer plate 101 and the second heat transfer plate 102 include the first fluid inflow pipe 4, the first fluid outflow pipe 5, and the second fluid inflow pipe of the second reinforcing side plate 2. 6, a first opening 111, a second opening 112, a third opening 113, and a fourth opening 114 are formed at positions corresponding to the second fluid outflow pipe 7, respectively. 111-114 form the inflow port of each 1st flow path, the outflow port of each 1st flow path, the inflow port of each 2nd flow path, and the outflow port of each 2nd flow path, respectively.

  Around the first opening 111 to the fourth opening 114, there is a flat seal portion (not shown) that covers the periphery and bulges to the front side or the back side of the first and second heat transfer plates 101, 102. Is provided. The seal portion has the third opening 113 and the fourth opening 114 sealed in the first flow path A through which the first fluid flows, and the first opening 111 in the second flow path B through which the second fluid flows. The second opening 112 is sealed. In this way, the second fluid is prevented from flowing into the first flow path A, and the first fluid is prevented from flowing into the second flow path B.

  The first heat transfer plate 101 and the second heat transfer plate 102 are alternately stacked, and the first inflow space 10 defined by the first opening 111 and the first outflow space 11 defined by the second opening 112. The second inflow space 12 defined by the third opening 113 and the second outflow space 13 defined by the fourth opening 114 are formed.

  As shown in FIGS. 4 and 5, the first and second heat transfer plates 101 and 102 have heat transfer promotion surfaces 115 and 117 that are inclined in opposite directions on the surfaces thereof. The heat transfer promotion surfaces 115 and 117 are parts that disturb the flow of each fluid to promote heat exchange, and the wave portions 116 and 118 are alternately repeated along the height direction (vertical direction in the figure). Is formed. As shown in FIGS. 8 and 9, the wave portions 116 and 118 provided on the first and second heat transfer plates 101 and 102 have a low central portion in the width direction (left and right direction in the figure) and are directed toward both sides. A wave part that is inclined in a waveform and has a solid line at the center on both sides, and a broken line that is adjacent to the wave part, is high at the center, and is inclined in a waveform toward both sides and the center part on both sides is low. Wave portions shown are alternately formed.

  The heat transfer facilitating surfaces 115 and 117 change the height of the wave portions 116 and 118 in the longitudinal direction A (one side from the central portion in the width direction), thereby changing the first and second heat transfer surfaces. The tops of the wave portions 116 and 118 of the heat plates 101 and 102 are joined together to reduce the number of joints, thereby suppressing an increase in fluid pressure loss. However, as shown in FIG. 7, the length L of the brazing 130 at the joint between the wave portions 116 and 118 is relative to the width W (see FIG. 4) of the first and second heat transfer plates 101 and 102. Try to maintain 30%.

  In addition, an angle θ formed by the longitudinal direction A of the wave portions 116 and 118 with respect to the height direction of the first and second heat transfer plates 101 and 102 (angle θ on the acute angle side, hereinafter referred to as a wave angle θ) is, for example, It is formed as large as 70 ° to 80 °, and the pitch P between the adjacent wave portions 116 and 118 is reduced to be approximately 4 mm, for example, so that heat transfer is improved.

  Then, the top portions of the wave portions 116 and 118 of the first heat transfer plate 101 and the second heat transfer plate 102 are joined to each other, and a meandering zigzag flow path is formed between the heat transfer plates 101 and 102. 1 and 2nd flow paths A and B are formed.

  The peripheral portions of the first and second heat transfer plates 101 and 102 are bent, and when these heat transfer plates 101 and 102 are stacked, the peripheral portions overlap each other to form the side surface of the plate heat exchanger 1. It is designed to form. A first flow path A through which the first fluid flows is formed between the front side of the first heat transfer plate 101 and the back side of the second heat transfer plate 102 surrounded by the side surfaces. A second flow path B through which the second fluid flows is formed between the back side of the first heat transfer plate 101 and the front side of the second heat transfer plate 102.

Next, the structure of the wave parts 116 and 118 provided in the first and second heat transfer plates 101 and 102 will be described.
FIG. 8 is a schematic explanatory view of the flow path of the wave portion 116 of the first heat transfer plate 101. The wave portion 116 has a wave shape, and its height is changed in the longitudinal direction (a). With respect to the height of the wave portion 116, when the C plane is used as a reference, the top portion is H1, the portion other than the top portion is H2, and H1> H2. A broken line indicates adjacent wave portions 116.

FIG. 9 is a schematic explanatory diagram of the flow path when the second heat transfer plate 102 is further superimposed on the first heat transfer plate 101. In the plate heat exchanger 1 laminated in this manner, the top of the solid wave portion 116 of the first heat transfer plate 101 is connected to the bottom of the broken wave portion 118 of the second heat transfer plate 102 and two points D and E. Join with.
In this case, if the wave portions 116 and 118 have a height of 0.2 mm or less, the fillet formation of the brazing material 130 between the heat transfer plates 101 and 102 can be suppressed, and the number of joining points can be adjusted.

  10 schematically shows the flow path of the heat transfer promoting surface of the first heat transfer plate 141 for comparison with FIG. 8, and FIG. 11 shows the first heat transfer plate 141 for comparison with FIG. The outline of the flow path of the heat transfer promotion surface when the second heat transfer plate 142 is overlapped is shown. In this plate heat exchanger, unlike the cases of FIGS. 8 and 9, the heat transfer promoting surface has a constant height H1, so that many contacts are provided between the first and second heat transfer plates 141 and 142. It will be possible. However, in this comparative example, when the number of junction points increases, the pressure loss deteriorates, and thus the power consumption of the air conditioner increases. In addition, reliability such as dust clogging is reduced. Furthermore, it becomes impossible to use fluids with large pressure loss such as water, hydrocarbons, and low GWP refrigerants.

12 is a diagram showing the relationship between the angle θ of the wave portions 116 and 118 (hereinafter referred to as the wave angle), the heat passage rate, and the pressure loss, and FIG. 13 is formed by the wave angle θ and the joint portion. It is a diagram which shows the relationship with the brazing material length l of a fillet.
When the wave angle θ is 70 ° to 80 °, as can be seen from FIG. 12, the heat passage rate is 1.1 times as compared with the case where the wave angle θ is 66 °, for example, but the pressure loss also increases. growing. Further, as can be seen from FIG. 13, as the wave angle θ increases, the length L (see FIG. 7) of one fillet brazing material at the joint between adjacent heat transfer plates increases, and the fluid formed between the fillets increases. Since the flow path is narrowed, the pressure loss is increased.
However, in the present invention, the pressure loss can be reduced even if the wave angle θ is 70 ° to 80 °.

FIG. 14 is a diagram showing the relationship between the pitch P of the wave portions 116 and 118, the heat passage rate, and the pressure loss. As can be seen from FIG. 14, when the pitch P of the wave portions 116 and 118 is reduced to about 4 mm, the heat passage rate increases due to the fluid turbulence effect and the area expansion rate also increases. Although the performance is improved, the pressure loss increases due to the increase of the junction points (see FIG. 15).
However, in the present invention, the pressure loss can be reduced even if the wave portion pitch L is about 4 mm.

FIG. 16 is a diagram showing the relationship between the width W of the heat transfer plate, the heat passage rate, and the pressure loss, and FIG. 17 is a diagram showing the relationship between the aspect ratio of the heat transfer plate, the heat passage rate, and the pressure loss.
As shown in FIG. 16, when the width W of the heat transfer plate is reduced, the cross-sectional area of the flow path is reduced, so that the speed of the fluid is increased and the heat passage rate is improved, but the pressure loss is also increased.
In relation to this width W, FIG. 17 shows that the heat transfer area per one heat transfer plate is constant, and the aspect ratio (height H / width W) is a parameter, and the heat transfer rate, pressure loss, plate heat It shows the weight relationship of the exchanger. As the aspect ratio increases, the heat transfer rate increases and the heat transfer area required for capacity can be reduced, so the weight of the plate heat exchanger is also reduced. However, pressure loss also increases.
In the present invention, since the aspect ratio is 4 to 6, the pressure loss can be reduced.

FIG. 18 is an explanatory diagram summarizing the number of joining points of the upper and lower heat transfer plates necessary for ensuring the strength based on the wave angle θ and the width W of the heat transfer plate.
The number of joining points is such that the brazing length L (see FIG. 7) at the joining portion of the wave portion of the adjacent heat transfer plate is 30% or more with respect to the width W of the heat transfer plate, and is generally used. This is the ratio of the brazing length L to the width W of the plate heat exchanger. In the present invention, the number of junction points is determined so as to satisfy this ratio. If the wave height of the wave portion is adjusted so that the number of junction points is obtained, the pressure loss of the fluid can be reduced while maintaining the strength even if the number of junction points is reduced.

  As an example, in order to increase the heat transfer performance of a heat transfer plate having a width W of 100 mm, a height H of 300 mm (aspect ratio 3), a wave pitch of 7 mm, and an angle θ of 66 °, heat transfer per heat transfer plate If the area is constant, the width W is 77 mm, the height H is 390 mm (aspect ratio 5), the wave pitch is 4 mm, and the angle θ is 80 °, the heat transfer rate increases by 30%. The weight of the heat exchanger can be reduced by 30%. On the other hand, the pressure loss increases 3.6 times if the junction point is not reduced, but can be suppressed to 1.8 times and half in the present invention in which the junction point is reduced.

In the present invention, the number of joining points of the first and second heat transfer plates 101 and 102 is such that the height of the wave portions 116 and 118 of the adjacent heat transfer plates 101 and 102 is changed for each wave in the fluid flow direction. May be adjusted.
In this case, the height of the wave having no junction point is 0.2 mm or less with respect to the height of the wave having the junction point, and the junction point of the adjacent heat transfer plates is adjusted. As a result, the change in the wave height causes the flow disturbance, so that the heat transfer performance is excellent, and the pressure loss is reduced by reducing the junction points.

Further, in the present invention, the number of junctions of the first and second heat transfer plates 101 and 102 is changed by changing the pitch P of the wave portions of the adjacent heat transfer plates 101 and 102 for each wave in the fluid flow direction. You may adjust it.
In this case, the number of junction points can be reduced in the region where the pitch P of the wave portions 116 and 118 is large, and the number of junction points can be increased in the region where the pitch P of the wave portions 116 and 118 is small. The turbulence of the flow due to the change in the pitch P of the wave portions 116 and 118 improves the heat transfer performance, and the pressure loss is reduced by reducing the junction points.

Furthermore, in the above description, the case where the number of junction points is adjusted by changing the height of the wave portions 116 and 118 of the first and second heat transfer plates 101 and 102 in a wave shape in the longitudinal direction a is shown. The grooves 116a and 118a may be provided at predetermined intervals in the longitudinal direction A of one surface of the portions 116 and 118 so as to change the height and adjust the number of joint points. FIGS. It is a schematic explanatory drawing of a road.
In FIG. 19, the second heat transfer plate 102a is superimposed on the first heat transfer plate 101a. Since only the portions 116b and 118b which are not the grooves 116a and 118a become high and only these portions become the junction points D and E, the pressure loss in the fluid flow direction can be suppressed small, and the heat transfer promoting effect of the wave angle θ and the aspect ratio Is obtained.

Next, the operation of the present invention will be described with reference to FIG.
The heat exchange operation between the first fluid and the second fluid in the plate heat exchanger configured as described above is performed as follows.
As shown by solid line arrows in FIG. 1, the first refrigerant in the low-temperature gas-liquid two-phase state flows from the first inflow pipe 4 and passes through the first inflow space 8 to the first flow paths A, A,.・ Inflow. On the other hand, the second refrigerant in the high-temperature gas state flows in from the second inflow pipe 6 and flows into the second flow paths B, B,.

  The first refrigerant flowing through the first flow path A and the second refrigerant flowing through the second flow path B exchange heat with each other via the first and second heat transfer plates 101 and 102, and the first refrigerant evaporates. Then, the second refrigerant condenses. Then, the first refrigerant that has evaporated to a gas state flows out from the first outflow pipe 5 through the first outflow space 11. On the other hand, the second refrigerant that has condensed into a liquid state flows out from the second outflow pipe 7 through the second outflow space 13.

  When the first refrigerant flowing through the first flow path A and the second refrigerant flowing through the second flow path B exchange heat with each other via the first and second heat transfer plates 101 and 102, the heat transfer promotion surface 115 and 117 pass through wave portions 116 and 118, and heat exchange is performed efficiently here.

  According to the first embodiment, even if the wave angle θ of the heat transfer plates 101 and 102 is increased to 70 ° to 80 ° and the wave pitch P is reduced to approximately 4 mm, the adjacent heat transfer plates 101 and 102 Necessary because the height of the wave portions 116 and 118 is changed in the longitudinal direction A so that the brazing length L at the joint portion of the wave portions 116 and 118 is maintained at 30% with respect to the width W. The fluid flow path can be configured with the minimum number of joints, and the increase in pressure loss can be suppressed and the heat exchange rate can be improved while maintaining the same strength as a conventional plate heat exchanger. . And since it is possible to suppress an increase in pressure loss while maintaining the same strength as the conventional one, it is difficult to clog foreign matters such as scales on the heat transfer plates 101 and 102, and heat transfer performance is maintained over a long period of time. Can be made more reliable.

  In the above case, since the width of the heat transfer plates 101 and 102 is reduced within the range of the aspect ratio of 4 to 6, the inlet flow velocity of the fluid flowing between the heat transfer plates 101 and 102 is increased. Heat transfer between the heat transfer plates 101 and 102 is further improved, the number of heat transfer plates 102 and 103 to be stacked can be reduced, and manufacturing costs such as material costs and processing costs can be reduced.

  Thus, since heat transfer is good and the increase in pressure loss can be minimized while maintaining strength, the plate heat exchanger 1 that is inexpensive and excellent in reliability can be provided.

Embodiment 2. FIG.
The second embodiment of the present invention relates to an air conditioner equipped with the plate heat exchanger 1 according to the first embodiment (not shown).
Since the air conditioner according to the second embodiment is equipped with the plate heat exchanger 1 according to the first embodiment, the power consumption is small.

It is the disassembled perspective view which showed typically the plate type heat exchanger which concerns on Embodiment 1 of this invention. It is a side view of the assembly state of FIG. 2 is a front view of a first reinforcing side plate in FIG. 1. It is a front view of the 1st heat exchanger plate of FIG. It is a front view of the 2nd heat-transfer plate of FIG. It is a front view of the 2nd reinforcement side plate of FIG. It is explanatory drawing of the state of a junction part when a 1st heat-transfer plate and a 2nd heat-transfer plate are piled up. It is a schematic explanatory drawing of the flow path of the wave part of the heat-transfer promotion surface of a 1st heat-transfer plate. It is a schematic explanatory drawing of the channel at the time of overlapping the 2nd heat transfer plate on the 1st heat transfer plate. It is explanatory drawing which shows the outline of the heat-transfer promotion surface of the 1st heat-transfer plate for the comparison with FIG. FIG. 10 is a schematic explanatory diagram of a heat transfer promotion surface when a first heat transfer plate and a second heat transfer plate for comparison with FIG. 9 are overlapped. It is a diagram which shows the relationship between wave angle (theta), a heat passage rate, and pressure loss. It is a diagram which shows the relationship between wave angle (theta) and the fillet length formed in a junction part. It is a diagram which shows the relationship between the pitch L of a wave part, a heat passage rate, and a pressure loss. It is a diagram which shows the relationship between a wave pitch and the number of junction points. It is a diagram which shows the relationship between the width W of a heat-transfer plate, a heat passage rate, and a pressure loss. It is a diagram which shows the relationship between the aspect ratio of a heat-transfer plate, a heat passage rate, and a pressure loss. It is explanatory drawing which shows the relationship between the number of junction points of the upper and lower heat-transfer plates required for strength ensuring from wave angle (theta) and the width W of a heat-transfer plate. It is a schematic explanatory drawing which shows the other example of the flow path of the wave part of the heat-transfer promotion surface of a 1st heat-transfer plate. It is a schematic explanatory drawing which shows the other example of the flow path at the time of overlapping the 2nd heat-transfer plate on the 1st heat-transfer plate.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Plate type heat exchanger, 2 1st reinforcement side plate, 3 2nd reinforcement side plate, 4 Inflow pipe of 1st fluid, 5 Outflow pipe of 1st fluid, 6 Inflow pipe of 2nd fluid, 7 Second fluid outflow pipe, 101 first heat transfer plate, 102 second heat transfer plate, 115, 117 heat transfer promoting surface, 116, 118 wave part, 130 wave part joint (brazing material), A first 1 channel, B 2nd channel, H height, W width, L brazing length, P wave portion pitch, θ wave angle.

Claims (7)

A first flow path and a second flow path are formed between the plurality of heat transfer plates that are stacked and joined, and the first fluid and the second fluid are passed through the first flow path and the second flow path, respectively. A plate-type heat exchanger that circulates between the heat plates and exchanges heat between the first fluid and the second fluid,
On the surface of the heat transfer plate, there is provided a heat transfer promoting surface that disturbs the flow of the first and second fluids to promote heat exchange,
The heat transfer promotion surface is alternately repeated with the ridges and valleys along the height direction of the heat transfer plate ,
A wave portion is formed by changing the height of the peak portion in a wave shape in the longitudinal direction of the peak portion,
The wave portions are formed so that the joining length of the wave portions at the joining portions of the adjacent heat transfer plates is maintained at 30% with respect to the width of the heat transfer plate, and the number of joining points of the heat transfer plates is determined. A plate heat exchanger characterized by adjustment. 2. The plate heat exchanger according to claim 1, wherein the wave portion is formed such that a high portion and a low portion of the adjacent wave portions are opposed to each other. Longitudinal forms wave angle to the height direction of the heat transfer plate of the wave portion is 70 ° to 80 °, according to claim 1, wherein the pitch between the wave portion is substantially 4mm or 2. The plate heat exchanger according to 2 . The plate type heat exchanger according to any one of claims 1 to 3, wherein a ratio of a height to a width of the heat transfer plate is 4 to 6. The plate-type heat exchanger according to any one of claims 1 to 4 , wherein the height of the wave portion of the heat transfer plate is changed for each wave in the fluid flow direction. The plate-type heat exchanger according to any one of claims 1 to 4 , wherein the pitch of the wave portions of the heat transfer plate is changed for each wave in the fluid flow direction. An air conditioner equipped with the plate heat exchanger according to any one of claims 1 to 6 .

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