WO2013076751A1

WO2013076751A1 - Plate-type heat exchanger and refrigeration cycle device using same

Info

Publication number: WO2013076751A1
Application number: PCT/JP2011/006460
Authority: WO
Inventors: 伊東　大輔
Original assignee: 三菱電機株式会社
Priority date: 2011-11-21
Filing date: 2011-11-21
Publication date: 2013-05-30
Also published as: GB201406880D0; US20140290921A1; GB2510738A

Abstract

A plate-type heat exchanger for which the plate thickness t of heat transfer plates (2, 3) is 0.2 mm or less, the pitch Λ of concavities and convexities (9, 10) is 4-7 mm, the distance h between the apexes of the concavities and convexities (9, 10) is 1.0-1.2 mm, and the area enlargement ratio Φ, defined as the value when the wavelength s corresponding to the length of the heat transfer plates (2, 3) between the apexes of the waves of the concavities and convexities (9, 10) of the heat transfer plates (2, 3) is divided by the pitch Λ of the concavities and convexities (9, 10), is 1.05-1.15.

Description

Plate heat exchanger and refrigeration cycle apparatus using the same

The present invention relates to a plate heat exchanger and a refrigeration cycle apparatus using the plate heat exchanger.

In the plate heat exchanger, heat transfer plates having a plurality of rows of corrugated irregularities are laminated, and a line connecting the apexes of the corrugated peaks (or the bottom points of the valleys) of the heat transfer plates is adjacent. The thing arrange | positioned so that it may cross | intersect with respect to a heat exchanger plate is proposed. And such a plate type heat exchanger has a wave height h corresponding to the interval between the apex of the corrugated peak of the heat transfer plate and the apex of the valley of the valley of the heat transfer plate adjacent to the heat transfer plate, for example, 1 It is set to about 6 mm to 2.2 mm.

When the wave height h is set in this way, the flow rate of the refrigerant is reduced as the refrigerant flow passage cross section is large, so that the heat transfer efficiency between the refrigerants is reduced. Therefore, in order to suppress the reduction in heat transfer efficiency, a plate heat exchanger in which the wave height h of the heat transfer plate is set to 0.5 to 1.5 mm (hydraulic diameter is 1 to 3 mm) has been proposed ( For example, see Patent Document 1).

However, when the refrigerant flow rate increases, the refrigerant easily gets over the waveform formed on the heat transfer plate, and may flow in the long axis direction of the heat transfer plate. That is, it is difficult for the refrigerant to spread in the short axis direction (width direction) of the heat transfer plate, and the flow velocity in the short axis direction may become non-uniform. Thereby, the flow of the refrigerant on the width side of the heat transfer plate is retained, and there is a possibility that the effective heat transfer area is reduced and dust clogging occurs.

Therefore, the wave angle θ, which is the angle formed by the line connecting the peaks of the corrugated peaks and the longitudinal direction of the heat transfer plate, is set to a small value (for example, 45 degrees) so that the refrigerant can easily spread in the short axis direction of the heat transfer plate. A plate-type heat exchanger designed to do this has been proposed (see, for example, Patent Document 2).
In the technique described in Patent Document 2, the wave pitch Λ, which is the distance between the peaks and peaks (or valleys and valleys) of the heat transfer plate, is set small (for example, 4 mm or less) to increase the refrigerant flow rate.

JP 2001-56192 A (for example, paragraph [0017] and FIG. 2 of the specification) JP 2011-516815 A (for example, paragraphs [0025] to [0028] of the specification)

The technique described in Patent Document 1 is to reduce the wave height h, thereby reducing the refrigerant flow path cross section and increasing the refrigerant flow velocity. Here, when the refrigerant flow rate increases, the refrigerant is easily stirred at the intersection of adjacent heat transfer plates, and the pressure loss increases. Thereby, the subject that the power consumption of the compressor which supplies a refrigerant | coolant to a plate type heat exchanger will increase occurred.
In addition, the refrigerant hardly spreads in the short axis direction (width direction) of the heat transfer plate, and the refrigerant flow in the short axis direction may become non-uniform. Thereby, the flow of the refrigerant on the width side of the heat transfer plate is retained, and there is a possibility that the effective heat transfer area is reduced and dust clogging occurs.

Since the technique described in Patent Document 2 sets the wave angle θ to 45 degrees, it is possible to suppress the “non-uniform refrigerant flow in the minor axis direction” as in the technique described in Patent Document 1. it can. However, since the setting of the wave pitch Λ is set to 4 mm or less, when the wave angle θ is set in this way, the distance in the minor axis direction between the junction points is reduced. As a result, when the heat transfer plate is brazed, the joining point is filled with the brazing material, and there is a possibility that the refrigerant flow path is blocked (increase in pressure loss).

Moreover, since the technique described in Patent Document 2 reduces the wave pitch Λ, the area enlargement ratio Φ increases. An increase in the area expansion rate Φ corresponds to an increase in the elongation of the plate material when the heat transfer plate is formed from the plate material. When the area enlargement ratio Φ increases, there is a possibility that the heat transfer plate is cracked or the thickness t is uneven.
That is, in the technique described in Patent Document 2, since the strength of the plate heat exchanger may be impaired, the plate material cannot be thinned, and the material cost and weight have increased. Further, since the thickness cannot be reduced, the processing cost has increased due to the increased set load during press processing.

The present invention has been made to solve at least one of the above-described problems, and provides heat transfer efficiency, reduction of pressure loss, blockage of a refrigerant flow path, cost increase suppression, and weight reduction. An object of the present invention is to provide a plate-type heat exchanger designed to be designed.

The plate heat exchanger according to the present invention includes an inflow port through which a fluid flows in, an outflow port through which the fluid flowing in from the inflow port flows out, and a substantially V-shaped unevenness arranged in a plurality from the inflow port toward the outflow port. A plate in which a plurality of heat transfer plates on which waves are formed are alternately turned upside down and stacked, and a flow path connecting the inlet and the outlet is formed in the space formed by the uneven waves of adjacent heat transfer plates Type heat exchanger, wherein the thickness t of the heat transfer plate is 0.2 mm or less, the uneven pitch Λ is 4 to 7 mm, the distance h between the apexes of the unevenness is 1.0 to 1.2 mm, When the value obtained by dividing the wavelength s corresponding to the length of the heat transfer plate between the vertices of the uneven wave by the uneven pitch Λ is defined as the area expansion rate Φ, the area expansion rate Φ is 1.05 to 1. 15.

According to the plate heat exchanger of the present invention, the plate thickness t is 0.2 mm or less, the uneven pitch Λ is 4 mm to 7 mm, and the distance h between the apexes of the uneven corresponding to the stacking direction is 1. 0mm to 1.2mm, and the area expansion ratio Φ is in the range of 1.05 to 1.15, so heat transfer efficiency, pressure loss reduction, refrigerant flow path blockage, cost increase suppression and weight reduction Can be achieved.

It is explanatory drawing of the plate type heat exchanger which concerns on Embodiment 1 of this invention. FIG. 2 is a schematic view of a heat transfer plate of the plate heat exchanger illustrated in FIG. 1. It is explanatory drawing of the various dimensions of the heat-transfer plate of the plate type heat exchanger shown in FIG. It is explanatory drawing of the relationship between wave pitch (LAMBDA) of the plate type heat exchanger shown in FIG. 1, and area expansion rate (PHI). It is a graph which shows the weight reduction amount of a plate type heat exchanger when changing the wave height h and wave angle (theta) as a parameter when the heat exchange amount of a plate type heat exchanger is 15 kW. It is a graph which shows the weight reduction amount of a plate-type heat exchanger when changing area expansion rate (PHI) and wave angle (theta) as a parameter. It is a figure explaining the distance between the junction points of an adjacent heat-transfer plate for every wave angle (theta). It is explanatory drawing of the refrigerating-cycle apparatus which concerns on Embodiment 2 of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Embodiment 1 FIG.
FIG. 1 is an explanatory diagram of a plate heat exchanger 100 according to the first embodiment. Here, Fig.1 (a) is a side view in the state in which the plate type heat exchanger 100 was assembled. FIG. 1B is a front view of the side plate 1. FIG. 1C is a front view of the heat transfer plate 2. FIG. 1D is a front view of the heat transfer plate 3. FIG. 1E is a front view of the side plate 4. FIG. 1 (f) is a diagram illustrating a state in which the heat transfer plate 2 and the heat transfer plate 3 are overlapped. FIG. 2 is a schematic view of the heat transfer plate 20 of the plate heat exchanger 100 illustrated in FIG. In FIG. 2, it is assumed that the solid line arrow represents the flow of the first refrigerant and the dotted line arrow represents the flow of the second refrigerant.
In addition, in the following drawings including FIG. 1, the relationship of the size of each component may be different from the actual one. With reference to FIG.1 and FIG.2, the structure of the plate-type heat exchanger 100 is demonstrated.

[Configuration of Plate Heat Exchanger 100]
First, the configuration of the plate heat exchanger 100 will be described.
The plate heat exchanger 100 heats, for example, a heat source side refrigerant (first refrigerant) conveyed from an outdoor unit on the heat source side and a heat medium (second refrigerant) conveyed from an indoor unit on the usage side. It is to be exchanged. That is, the plate heat exchanger 100 is a heat exchanger of a heat medium such as refrigerant versus refrigerant or refrigerant versus water or brine. The plate heat exchanger 100 is formed with a first refrigerant channel X through which the first refrigerant flows and a second refrigerant channel Y through which the second refrigerant flows so that the first refrigerant and the second refrigerant are not mixed. Has been.
As shown in FIG. 1, the plate heat exchanger 100 includes a heat transfer plate 20 and

side plates

1 and 4 that reinforce the plate heat exchanger 100.

(Heat transfer plate 20)
As shown in FIG. 2, the heat transfer plate 20 forms the first refrigerant flow paths X and Y for the first refrigerant and the second refrigerant. The heat transfer plate 20 is composed of two types of plates, that is,

heat transfer plates

2 and 3 having a rectangular planar shape. The heat transfer plate 2 is obtained by inverting the heat transfer plate 3 upside down.
The heat transfer plate 20 has a substantially V-shaped wave on the surface thereof, and the heat transfer plate 2 formed in a plurality of rows in the “vertical direction” and the lower direction of the heat transfer plate 2 are reversed. The arranged heat transfer plates 3 are alternately arranged oppositely (stacked). Therefore, the heat transfer plate 3 having the reverse direction of the heat transfer plate 2 is arranged behind the heat transfer plate 2, and the heat transfer plate 2 is arranged behind the heat transfer plate 3. .
Here, the “vertical direction” indicates not only the direction perpendicular to the surface on which the plate heat exchanger 100 is installed, but also the general vertical direction.
Moreover, although the shape of the heat transfer plate 20 in plan view is described as being rectangular, the shape is not limited thereto, and may be, for example, a square. Further, the top and bottom of the heat transfer plate 20 correspond to the top and bottom of the paper surface of FIG. That is, the top of the heat transfer plate 20 corresponds to the side where the first opening 11 and the fourth opening 14 described later are present, and the bottom of the heat transfer plate 20 is the second opening 13 and the third opening 12. Corresponds to the side.

The heat transfer plate 2 is provided in parallel to the heat transfer plate 3 and the

side plates

1 and 4, and is a plate-like member disposed to face the adjacent heat transfer plate 3.
As shown in FIG. 1C, the heat transfer plate 2 is formed with a plurality of rows of waves of unevenness 9 having a substantially inverted V shape when viewed in plan. And the line | wire which tied the vertex (or bottom point) of the unevenness | corrugation 9 is formed symmetrically about the centerline parallel to the longitudinal direction (up-down direction of the paper surface of FIG.1 and FIG.2) of the heat-transfer plate 2. As shown in FIG. Further, the unevenness 9 is formed so that a line connecting the apexes of the unevenness 9 forms a predetermined angle with respect to the center line.

The heat transfer plate 3 also has an angle other than the angle formed by the line connecting the tops (or bottom points) of the irregularities 10 of the heat transfer plate 3 and the longitudinal direction of the heat transfer plate 3 (the vertical direction of the paper surface in FIGS. 1 and 2). Is the same as the configuration of the heat transfer plate 2. That is, the heat transfer plate 3 is a plate-like member that is provided in parallel to the heat transfer plate 2 and the

side plates

1 and 4 and is disposed to face the adjacent heat transfer plate 2.
As shown in FIG. 1D, the heat transfer plate 3 is formed with a plurality of rows of waves of substantially V-shaped irregularities 10 when viewed in plan. A line connecting the apexes (bottom points) of the unevenness 10 is formed symmetrically with respect to a center line parallel to the longitudinal direction of the heat transfer plate 3. The unevenness 10 is formed so that a line connecting the apexes of the unevenness 10 forms a predetermined angle with respect to the center line.

The unevenness 9 formed on the heat transfer plate 2 and the unevenness 10 formed on the heat transfer plate 3 increase the area where the heat (or cold) of the first refrigerant and the second refrigerant is released, and increase the heat exchange efficiency. It is formed for such reasons. Here, when the heat transfer plate 2 and the heat transfer plate 3 are viewed in a state of being opposed to each other as shown in FIG. 1 (f), a line connecting the vertices of the unevenness 9 of the heat transfer plate 2 and It is provided so that the line which connected the vertex of the unevenness | corrugation 10 of the heat plate 3 may cross | intersect. In addition, the cross-section of the

unevennesses

9 and 10 formed on the

heat transfer plates

2 and 3 may be, for example, a saw shape or a wave shape (curved surface). The

irregularities

9 and 10 will be described in detail with reference to FIG.

As shown in FIGS. 1C and 1D, the heat transfer plate 2 and the heat transfer plate 3 include a first opening 11 through which the first refrigerant flowing into the plate heat exchanger 100 flows, and the plate. A second opening 13 through which the first refrigerant flowing out of the heat exchanger 100 flows is formed. The heat transfer plate 2 and the heat transfer plate 3 also have a third opening 12 through which the second refrigerant flowing into the plate heat exchanger 100 flows, and a second refrigerant flowing out from the plate heat exchanger 100. Four openings 14 are formed.
That is, the first opening 11 formed in the heat transfer plate 2 corresponds to the inlet of the first refrigerant flowing into the first refrigerant flow path X formed between the

heat transfer plates

2 and 3, and The second opening 13 formed in the heat plate 2 corresponds to the outlet of the first refrigerant flowing into the first refrigerant channel X. The second refrigerant passes through the third opening 12 and the fourth opening 14 formed in the heat transfer plate 2 without flowing into the first refrigerant flow path X.
The third opening 12 formed in the heat transfer plate 3 corresponds to the inlet of the second refrigerant flowing into the second refrigerant flow path Y formed between the

heat transfer plates

3 and 2, and The fourth opening 14 formed in the heat plate 3 corresponds to the outlet of the second refrigerant that has flowed into the second refrigerant flow path Y. Note that the first refrigerant passes through the first opening 11 and the second opening 13 formed in the heat transfer plate 2 without flowing into the second refrigerant flow path Y.
Note that the first openings 11 of the

heat transfer plates

2 and 3 communicate with each other. The same applies to the second opening 13, the third opening 12, and the fourth opening 14.

Further, as shown in FIG. 2, the heat transfer plate 2 and the heat transfer plate 3 form a first refrigerant flow path X through which the first refrigerant flows by the rear surface of the heat transfer plate 2 and the front surface of the heat transfer plate 3, A second refrigerant flow path Y through which the second refrigerant flows is formed by the rear surface of the heat transfer plate 3 and the front surface of the heat transfer plate 2. In this example, “front” corresponds to “right of paper” in FIG. 2, and “rear” corresponds to “left of paper”.

(Side plates 1, 4)
The

side plates

1 and 4 reinforce the plate heat exchanger 100.
The side plate 1 is provided in parallel to the heat transfer plate 20 and the side plate 4, and is disposed opposite to the foremost heat transfer plate 2 as shown in FIG. . Further, the side plate 4 is provided in parallel to the heat transfer plate 20 and the side plate 1, and is disposed opposite to the rearmost heat transfer plate 3 as shown in FIG. It is.
The side plate 1 includes a first refrigerant inflow pipe 5 for allowing the first refrigerant to flow into the plate heat exchanger 100 and a first refrigerant outflow pipe 7 for allowing the first refrigerant to flow out of the plate heat exchanger 100. Is provided. The side plate 1 has a second refrigerant inflow pipe 6 for allowing the second refrigerant to flow into the plate heat exchanger 100, and a second refrigerant outflow for causing the second refrigerant to flow out of the plate heat exchanger 100. A tube 8 is provided.

[Dimensions of Heat Transfer Plate 20]
FIG. 3 is an explanatory diagram of various dimensions of the heat transfer plate 20 of the plate heat exchanger 100 shown in FIG. FIG. 3A is a plan view of the heat transfer plate 20 using the heat transfer plate 2 as an example. Moreover, FIG.3 (b) is sectional drawing in the surface orthogonal to the line | wire which connected the vertex (bottom point) of the unevenness | corrugation 9 of the heat-transfer plate 2 of Fig.3 (a). FIG. 4 is an explanatory diagram of the relationship between the area expansion ratio Φ and the wave pitch Λ of the plate heat exchanger 100 shown in FIG. In FIG. 4, the plate thickness t is 0.2 mm, and the wave height h is 1.4 mm.

In the first embodiment, the wave angle θ, wave pitch Λ, wave height h, wavelength s, area enlargement ratio Φ, and plate thickness are specified in the wave shape specification of the

irregularities

9, 10 formed on the heat transfer plate 20. The variable t is adopted.

The wave angle θ corresponds to the wave spreading angle with respect to the wave arrangement direction of the substantially V-shaped

irregularities

9 and 10. That is, as shown in FIG. 3, the wave angle θ is an angle formed by a line connecting the vertices (or bottom points) of the unevenness of the heat transfer plate 20 with respect to the longitudinal direction of the heat transfer plate 20.
As shown in FIG. 3B, the wave pitch Λ corresponds to the length between adjacent vertices.
As shown in FIG. 3B, the wave height h corresponds to the length between the bottom and top of the unevenness.

The wavelength s corresponds to the length of the heat transfer plate 20 between adjacent vertices, as shown in FIG. This wavelength s is expressed by the following (Formula 1). In addition, R1 of the following formula | equation is a curvature radius corresponding to the distance of the perpendicular direction from the curvature center O shown to FIG. Θ represents a range in which the distance from the center of curvature O to the waves of the

unevennesses

9 and 10 is the same radius of curvature R1.

Formula 1

The plate thickness t corresponds to the thickness of the heat transfer plate 20.
As shown in FIG. 3B, the area enlargement ratio Φ is obtained by dividing the wavelength s at a predetermined wave height h by the wave pitch Λ. Further, the area enlargement ratio Φ can also be represented by the wave height h and the wave pitch Λ because the wavelength s is represented by the above (Formula 1). When the area expansion rate Φ is small, the elongation of the plate material is small, and when the area expansion rate Φ is large, the elongation of the plate material is large. FIG. 4 shows the value of the area enlargement ratio Φ when the plate thickness t is 0.2 mm and the wave height h is 1.4 mm.

[Setting of wave height h and wave angle θ when heat exchange amount is 15 kW]
FIG. 5 is a graph showing the weight reduction amount of the plate heat exchanger 100 when the wave height h and the wave angle θ are changed as parameters when the heat exchange amount of the plate heat exchanger 100 is 15 kW. is there. In FIG. 5, the plate thickness t is 0.2 mm.
As shown in FIG. 5, the wave height h is preferably 1.0 to 1.2 mm. In the case of this wave height h range, the area enlargement ratio Φ is small and the elongation of the plate material is small. Therefore, by adjusting the wave angle θ, the weight reduction ratio can be set to 20% or more or a value close thereto. This is because it can.
When the wave height h is 1.0 to 1.2 mm, the wave angle θ may be set within a range of 40 degrees to 50 degrees. This is because, in the range of the wave angle θ, it is possible to prevent the refrigerant flow in the minor axis direction of the heat transfer plate 20 from becoming uneven while securing the weight reduction rate. Further, in the range of the wave angle θ, the flow of the refrigerant on the width side of the heat transfer plate 20 stays, and the reduction of the effective heat transfer area and the occurrence of clogging of dust are suppressed, and the pressure loss is reduced. Because it can.
Furthermore, if the wave height h is 1.0 to 1.2 mm, it is possible to suppress the occurrence of cracks in the heat transfer plate 20 and uneven thickness t because the elongation of the plate material is small. it can.

Here, when the wave height h is larger than 1.2 mm, compared with the case where the wave height h is 1.0 to 1.2 mm, the area enlargement ratio Φ is increased and the elongation of the plate material is increased. There is a possibility that a crack in the heat transfer plate 20 or an uneven thickness t may occur.

When the wave height h is less than 1.0 mm, as compared with the case where the wave height h is 1.0 to 1.2 mm, the area expansion rate Φ is reduced and the elongation of the plate material is reduced. However, in this wave height h range, the refrigerant flow path is small, so the pressure loss is large. That is, when the wave height h is less than 1.0 mm, in order to set the heat exchange amount to 15 kW, it is necessary to increase the number of stacked heat transfer plates 20 in order to reduce the pressure loss. The weight of the heat exchanger 100 cannot be reduced.

[Setting of area expansion rate Φ and wave angle θ when heat exchange amount is 15 kW and 9 kW]
FIG. 6 is a graph showing the weight reduction amount of the plate heat exchanger 100 when the area expansion ratio Φ and the wave angle θ are changed as parameters. In FIG. 6, the plate thickness t is 0.2 mm. In addition, the continuous line of FIG. 6 is a result in the plate type heat exchange whose heat exchange amount is 15 kW, and a dotted line is a result in the plate type heat exchanger whose heat exchange amount is 9 kW.

As shown in FIG. 6, the area expansion rate Φ is preferably 1.05 to 1.15 in any heat exchange amount. This is because, in the case of the area enlargement ratio Φ, the weight reduction ratio can be set to 20% or more or a value close thereto by adjusting the wave angle θ.

When the area enlargement ratio Φ is set to 1.05 to 1.15, the wave angle θ may be set within a range of 40 degrees to 50 degrees. This is because, in the range of the wave angle θ, it is possible to prevent the refrigerant flow in the minor axis direction of the heat transfer plate 20 from becoming uneven while securing the weight reduction rate. Further, in the range of the wave angle θ, the flow of the refrigerant on the width side of the heat transfer plate 20 stays, and the reduction of the effective heat transfer area and the occurrence of clogging of dust are suppressed, and the pressure loss is reduced. Because it can.

From the description of FIGS. 5 and 6 above, when the thickness t of the heat transfer plate 20 is reduced to 0.2 mm or less, the plate heat exchanger is independent of the heat exchange amount of the plate heat exchanger 100. In order to reduce the weight of 100, the following wave height h, area enlargement ratio Φ, and wave angle θ may be set. That is, the wave height h is set to 1.0 to 1.2 mm, the wave angle θ is set to a range of 40 degrees to 50 degrees, and the area enlargement ratio Φ is set to 1.05 to 1.15. . Thereby, the optimal weight reduction effect in the case of reducing the thickness t to 0.2 mm or less can be obtained.

In FIGS. 5 and 6, the case where the plate thickness t is 0.2 mm has been described as an example. However, even when the plate thickness t is less than 0.2 mm, the wave pitch Λ and the wave height h are set as described above. By setting the range (value), the weight reduction rate is increased, the refrigerant flow in the minor axis direction of the heat transfer plate 20 is prevented from becoming non-uniform, and the heat transfer plate 20 is cracked or the thickness t is decreased. Bias suppression can be realized.

[Setting of wave pitch Λ]
In the description of FIGS. 5 and 6, the wave angle θ is set to 40 to 50 degrees, and the wave height h is set to 1.0 to 1.2 mm, so that the heat exchange of the plate heat exchanger 100 is performed. It has been explained that an optimum weight reduction effect can be obtained by reducing the plate thickness t regardless of the amount. In addition to this, the wave pitch Λ is preferably 4 mm or more, and will be described below with reference to FIG.

FIG. 7 is a diagram for explaining the distance between junction points of adjacent

heat transfer plates

2 and 3 for each wave angle θ. In FIG. 7A, the wave angle θ is 65 degrees, and in FIG. 7B, the wave angle θ is 45 degrees. Further, the junction point corresponds to the position of the point where the line connecting the vertices of the unevenness of the heat transfer plate 2 and the line connecting the vertices of the unevenness of the heat transfer plate 3 intersect. Moreover, the dotted line illustrated in FIG. 7A and FIG. 7B represents a line connecting the vertices of the unevenness formed in the adjacent

heat transfer plates

2 and 3. Moreover, the point a and the point b described in FIG. 7 are junction points of the

heat transfer plates

2 and 3 and are closest to each other in the minor axis direction among the junction points. Furthermore, L1 is the distance between point a and point b when the wave angle θ is 65 degrees, and L2 is the distance between point a and point b when the wave angle θ is 45 degrees.

As shown in FIG. 7A and FIG. 7B, when the wave angle θ is reduced from 65 degrees to 45 degrees, the refrigerant flows in the short axis direction of the

heat transfer plates

2 and 3 in a non-uniform manner. It is possible to prevent the refrigerant flow on the width side of the

heat transfer plates

2 and 3 from staying, and to reduce the effective heat transfer area and clogging of dust.
On the other hand, when the wave angle θ is reduced from 65 degrees to 45 degrees, the distance L1> the distance L2. That is, the distance between the junction points closest to each other in the minor axis direction is reduced.

Therefore, when the wave angle θ is set to 45 degrees, if the wave pitch Λ is too narrow, the distance L2 is further reduced, so that the junction is filled with the brazing material, and the refrigerant flow path is blocked (pressure). (Increased loss) may occur. Therefore, the wave pitch Λ is preferably set to 4 to 7 mm. As a result, the radius of the minimum fillet is about 1.5 mm, and about 50% or more is secured as the refrigerant flow path, so that blocking of the refrigerant flow path is suppressed.
If the wave pitch Λ is excessively widened, the number of junctions between the adjacent heat transfer plate 2 and the heat transfer plate 3 decreases, resulting in a decrease in heat transfer efficiency. However, by setting the wave pitch Λ to 4 to 7 mm, it is possible to suppress a decrease in heat transfer efficiency.

[Effect of plate heat exchanger 100 according to Embodiment 1]
In the plate heat exchanger 100 according to the first embodiment, the thickness t of the heat transfer plate 20 is set to 0.2 mm or less, the wave height h is set to 1.0 to 1.2, and the wave angle θ Is set to 40 to 50 degrees, and the wave pitch Λ is set to 4 to 7 mm, thereby reducing heat transfer efficiency, reducing pressure loss, equalizing the refrigerant flow in the short axis direction, and blocking the refrigerant flow path. In addition, cost increase can be suppressed and weight can be reduced.

Specifically, the heat transfer plate 20 has a wave height h set to 1.0 to 1.2 mm, a wave angle θ set to 40 degrees to 50 degrees, and an area enlargement ratio Φ of 1.05 to 1. 15 (see FIGS. 5 and 6). In the range of the wave height h, the area enlargement ratio Φ is decreased, and the elongation of the plate material is small. The refrigerant flows in the short axis direction of the heat transfer plate 20 in a non-uniform manner. The occurrence of cracks in the heat plate 20, uneven thickness t, and the like, and the refrigerant flow path being made thinner, increase the flow rate of the refrigerant and improve the heat transfer efficiency. can do.

In the heat transfer plate 20 of the plate heat exchanger 100, the wave angle θ is set to 40 degrees to 50 degrees, and the wave pitch Λ is set to 4 to 7 mm (see FIG. 7).
As a result, when the wave pitch Λ is excessively narrowed, the joint point is filled with the brazing material, and blockage of the refrigerant flow path is suppressed. Further, by excessively widening the wave pitch Λ, the number of junctions between the heat transfer plate 2 and the heat transfer plate 3 is reduced, and the heat transfer efficiency is suppressed from being lowered.

Further, the heat transfer plate 20 of the plate heat exchanger 100 has a wave height h set to 1.0 mm to 1.2 mm and a wave pitch Λ set to 4 to 7 mm. 05 to 1.15 can be satisfied. Thereby, since the diameter of the refrigerant flow path is reduced, the flow rate of the refrigerant is increased, and the heat transfer efficiency can be improved.
Further, it is possible to reduce the elongation of the plate material when forming the heat transfer plate 20 from the plate material, and it is possible to suppress the occurrence of cracks in the heat transfer plate 20, unevenness of the plate thickness t, and the like. That is, the strength of the plate heat exchanger 100 is not easily impaired (high strength). Thereby, the plate material can be thinned, and the material cost and weight can be reduced. And since the setting load at the time of press work can be set small by the part which can be thinned, processing cost can be reduced.

If the thickness t, wave height h, wave angle θ, and wave pitch Λ of the heat transfer plate 20 deviate from the ranges described in the first embodiment, there are the following adverse effects.
First, if the plate thickness t is out of the range, the weight of the plate heat exchanger 100 is increased in the first place.
Further, when the wave height h and the wave angle θ are out of the range, the increase in the weight of the plate heat exchanger 100, the occurrence of cracks in the heat transfer plate 20 and the deviation of the plate thickness t, or the increase in pressure loss. If the number of stacked heat transfer plates 20 is increased, the weight of the plate heat exchanger 100 is increased.
Further, when the wave pitch Λ is out of the range, the heat transfer efficiency is lowered due to the blockage of the refrigerant flow path or the reduction of the junction points between the adjacent

heat transfer plates

2 and 3.

[Others]
As described above, the plate heat exchanger 100 realizes suppression of pressure loss and high strength. Therefore, the plate heat exchanger 100 can suppress pressure loss even when supplied with, for example, a CO ₂ refrigerant, a hydrocarbon refrigerant, a low-density flammable low GWP refrigerant, etc. The deformation of the heat transfer plate 20 and the like can be suppressed.
Moreover, since the plate-type heat exchanger 100 can reduce the elongation rate of the plate material as described above, the elongation rate is 30% or more of stainless steel (elongation rate 40%), copper (elongation rate 40%), Even if the heat transfer plate 20 is constituted by not only industrial aluminum (elongation rate 30%) but also metals such as titanium (elongation rate 14%) and corrosion-resistant aluminum (elongation rate 16%) as small as 20% or less. Alternatively, the heat transfer plate 20 may be made of synthetic resin or the like.

In addition, although the heat transfer plate 2 is the heat transfer plate 3 upside down and has the same configuration, the heat transfer plate 2 is not limited thereto. That is, the heat transfer plate 2 and the heat transfer plate 3 have a thickness t of 0.2 mm or less, a wave height h in the range of 1.0 to 1.2 mm, a wave angle θ in the range of 40 degrees to 50 degrees, and a wave pitch. It is sufficient that Λ is set in the range of 4 to 7 mm and the area enlargement ratio Φ is set in the range of 1.05 to 1.15.

Embodiment 2.
FIG. 8 is an explanatory diagram of a refrigeration cycle apparatus (air conditioner) according to Embodiment 2 of the present invention. In the second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and differences from the first embodiment will be mainly described. The refrigeration cycle apparatus according to the second embodiment is, for example, an air conditioner, a power generator, a food heat sterilization apparatus or the like equipped with a plate heat exchanger. In the following description, a case where the refrigeration cycle apparatus is the air conditioner 200 will be described as an example.

The air-conditioning apparatus 200 according to Embodiment 2 uses the heat of the indoor unit 102 as the cooling heat of the heat source side refrigerant that flows through the one outdoor unit 101, the one indoor unit 102, and the outdoor unit 101 that are heat source units. It has a heat medium converter 103 for transmitting to the medium.
The outdoor unit 101 and the heat medium relay unit 103 are connected by a refrigerant pipe 120 that conducts the heat source side refrigerant (first refrigerant) to constitute a refrigerant circulation circuit A. Further, the heat medium converter 103 and the indoor unit 102 are connected by a heat medium pipe 121 that conducts the heat medium (second refrigerant), and constitutes a heat medium circuit B.

The outdoor unit 101 is mounted with at least a heat source side heat exchanger 110, a compressor 118, and an expansion device 111.
The indoor unit 102 is equipped with at least a use side heat exchanger 112.
At least the plate heat exchanger 100 and the pump 119 according to the first embodiment are mounted on the heat medium relay unit 103.
Although an example in which the plate heat exchanger 100 is mounted on the heat medium converter 103 will be described, at least one of the outdoor unit 101, the indoor unit 102, and the heat exchanger of the heat medium converter 103 is used. It is sufficient that the plate heat exchanger 100 is employed.
In the second embodiment, the air conditioning apparatus 200 that performs the cooling operation is described as an example of the refrigeration cycle apparatus. However, the refrigerant circulation circuit A may be provided with a four-way valve or the like to enable the heating operation. Needless to say.

The heat source side heat exchanger 110 functions as a condenser and performs heat exchange between the heat source side refrigerant flowing through the refrigerant pipe 120 and the outdoor air. One of the heat source side heat exchangers 110 is connected to the plate heat exchanger 100 and the other is connected to the discharge side of the compressor 118.
The compressor 118 compresses the heat source side refrigerant and conveys it to the refrigerant circuit A. The compressor 118 has a discharge side connected to the heat source side heat exchanger 110 and a suction side connected to the plate heat exchanger 100.
The expansion device 111 expands the heat source side refrigerant flowing through the refrigerant pipe 120 by reducing the pressure. One of the expansion devices 111 is connected to the heat source side heat exchanger 110, and the other is connected to the plate heat exchanger 100. The throttling device 111 may be composed of, for example, a capillary tube or a solenoid valve.

The usage-side heat exchanger 112 performs heat exchange between the heat medium flowing through the heat medium pipe 121 and the air in the air-conditioning target space. One of the use side heat exchangers 112 is connected to the plate heat exchanger 100 and the other is connected to the suction side of the pump 119.

The plate heat exchanger 100 exchanges heat between the heat source side refrigerant and the heat medium. The plate heat exchanger 100 is connected to the suction side of the compressor 118 and the expansion device 111 via the refrigerant pipe 120. Further, the plate heat exchanger 100 is connected to the use side heat exchanger 112 and the pump 119 via the heat medium pipe 121. That is, the plate heat exchanger 100 is cascade-connected to the refrigerant circuit A and the heat medium circuit B.
The pump 119 conveys the heat medium to the heat medium circulation circuit B. The pump 119 has a suction side connected to the use side heat exchanger 112 and a discharge side connected to the plate heat exchanger 100.

[Description of operation]
The flow of the heat source side refrigerant in the refrigerant circuit A will be described.
The low-temperature / low-pressure heat source side refrigerant is compressed by the compressor 118 and discharged as a high-temperature / high-pressure gas refrigerant. The high-temperature and high-pressure gas refrigerant discharged from the compressor 118 flows into the heat source side heat exchanger 110. And it becomes a high-pressure liquid refrigerant while radiating heat to the outdoor air by the heat source side heat exchanger 110. The high-pressure liquid refrigerant that has flowed out of the heat source side heat exchanger 110 is expanded by the expansion device 111 and becomes a low-temperature, low-pressure two-phase refrigerant. This low-temperature, low-pressure two-phase refrigerant flows into the plate heat exchanger 100 that functions as an evaporator. The low-temperature / low-pressure two-phase refrigerant absorbs heat from the heat medium circulating in the heat medium circuit B, and becomes a low-temperature / low-pressure gas refrigerant while cooling the heat medium. The gas refrigerant that has flowed out of the plate heat exchanger 100 is sucked into the compressor 118 again.

Next, the flow of the heat medium in the heat medium circuit B will be described.
The heat medium pressurized and discharged by the pump 119 flows into the plate heat exchanger 100, and the cold heat of the heat source side refrigerant of the plate heat exchanger 100 is transmitted to the heat medium. When this heat medium flows out of the plate heat exchanger 100, it flows into the use side heat exchanger 112. The heat medium absorbs heat from the indoor air by the use side heat exchanger 112, thereby cooling the air-conditioning target space. The heat medium flowing out from the use side heat exchanger 112 is sucked into the pump 119 again.

1, 4 side plate, 2, 3, 20 heat transfer plate, 5 first refrigerant inflow pipe, 6 second refrigerant inflow pipe, 7 first refrigerant outflow pipe, 8 second refrigerant outflow pipe, 9 irregularities, 10 irregularities, 11 1st opening part, 12 3rd opening part, 13 2nd opening part, 14 4th opening part, 100 plate type heat exchanger, 101 outdoor unit, 102 indoor unit, 103 heat medium converter, 110 heat source side heat exchanger , 111 throttle device, 112 utilization side heat exchanger, 118 compressor, 119 pump, 120 refrigerant piping, 121 heat medium piping, 200 air conditioner, A refrigerant circulation circuit, B heat medium circulation circuit, X first refrigerant flow path , Y Second refrigerant flow path.

Claims

An inflow port through which fluid flows in, an outflow port through which fluid flows in from the inflow port, and heat transfer in which a plurality of substantially V-shaped uneven waves arranged from the inflow port toward the outflow port are formed A plate-type heat exchanger in which a plurality of plates are alternately turned upside down and stacked, and a flow path that connects the inlet and the outlet is formed in a space formed by uneven waves of the adjacent heat transfer plates. There,
The thickness t of the heat transfer plate is 0.2 mm or less,
The uneven pitch Λ is 4 to 7 mm,
The distance h between the tops of the irregularities is 1.0 to 1.2 mm;
When the value obtained by dividing the wavelength s corresponding to the length of the heat transfer plate between the vertices of the unevenness of the heat transfer plate by the pitch Λ of the unevenness is defined as the area enlargement rate Φ, the area enlargement rate A plate heat exchanger characterized in that Φ is 1.05 to 1.15.
The plate heat exchanger according to claim 1, wherein the wave spreading angle θ with respect to the arrangement direction of the substantially V-shaped uneven waves is 40 degrees to 50 degrees.
All the heat transfer plates
The plate type heat exchanger according to claim 1 or 2, wherein the wave spread angle θ, the plate thickness t, the pitch Λ, and the distance h are set to the same value.
The heat transfer plate is
The plate heat exchanger according to any one of claims 1 to 3, wherein the plate heat exchanger is made of titanium, corrosion-resistant aluminum, or synthetic resin.
A refrigeration cycle apparatus, wherein two refrigerant circuits are cascade-connected via the plate heat exchanger according to any one of claims 1 to 4.