JP2002107073A - Laminated heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated heat exchanger that has high pressure-tight strength and is compact with satisfactory heat transfer performance. SOLUTION: A plate 1 is folded into a wave shape to form channels 3 and 5 on both surfaces. The projected part at the upper stage and the recessed part at the lower stage are butted, and the recessed part at the upper stage and the projected part at the lower stage are butted for lamination. The channels 3 and 5 are formed adjacent to the direction along the plate 1, and the channels 3 and 5 are also formed on the multistage in the direction of lamination. Fluids A and B flow alternately in the channels 3 and 5 adjacent to the direction and along the plate 1, and the same kind of fluid A or B flows in the channels 3 and 5, in the direction in which the plates 1 are laminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a stacked heat exchanger, and more particularly to a stacked heat exchanger suitable for a refrigeration cycle of a chiller unit or the like.

[0002]

2. Description of the Related Art In general, a laminated heat exchanger has a structure in which a flow path is formed between a plurality of stacked plates, and heat is exchanged by alternately flowing fluids having different temperatures through these flow paths. This has the advantage of being significantly more compact than conventional heat exchangers such as multi-tube heat exchangers.

The most common type of herringbone type heat exchanger has a herringbone-shaped wave-shaped heat transfer surface which is inclined down from both directions from the longitudinal centerline of the plate. Forms a heat exchanger.

In the above-mentioned laminated heat exchanger, a large number of contact points are formed between the peaks of the herringbone-shaped corrugated heat transfer surfaces of the laminated plates, and a pressure resistance of about 3 MPa (10 ⁶ Pascal) at maximum is obtained. However, since a high-pressure part and a low-pressure part are formed every other plate, a force acts in the direction of peeling between the plates, and the pressure resistance strength (up to about 5 MPa) that can be used as a condenser for high-pressure refrigerant such as R410A ) Was difficult to secure.

[0005] In the above-mentioned prior art, the flow of the fluid is restricted at the contact point between the peaks of the corrugated heat transfer surface, so that the pressure loss increases particularly as the flow rate increases. Further, in the above prior art, although the heat transfer performance on the single-phase side can be sufficiently obtained, the heat transfer performance during the phase change on the refrigerant side is significantly inferior to that on the single-phase side. Reducing the size of each component in a refrigeration cycle such as a chiller unit has various advantages in reducing the size of the device and saving space. However, it has been practically difficult to make the above-described conventional heat exchanger more compact because the pressure loss is significantly increased and the heat transfer performance on the refrigerant side is a bottleneck.

[0006]

As a measure for reducing the water side pressure loss, as described in the prior art of Japanese Patent Application Laid-Open No. Hei 7-260384, the number of points of contact between the peaks of the waveform heat transfer surface is determined. What is necessary is just to form the angle of a wave so that it may become small.
However, in this case, the pressure loss can be reduced, but the pressure resistance is reduced this time, and it is necessary to consider this.

Japanese Patent Application Laid-Open No. 7-260384 discloses, as an improvement of the above-mentioned prior art, a vertical groove structure having a small flow resistance substantially along a flow direction of a fluid formed on a heat transfer surface of a plate. According to this, without lowering the pressure resistance,
Although the pressure loss on the water side can be reduced, since a part of the fluid flows by bypassing the vertical groove structure, the heat transfer performance is reduced, and it is necessary to consider this.

As a method for improving the heat transfer performance of a laminated heat exchanger having a heat transfer surface other than the herringbone type, there is a technique described in Japanese Patent Application Laid-Open No. Hei 6-123578.
Here, in order to further increase the heat transfer area of the heat exchange medium flow path composed of two forming plates and promote heat transfer,
A large number of minute projections are provided on the inner surface of the flow channel by embossing. However, further consideration was needed to simultaneously improve the pressure resistance.

It is an object of the present invention to provide a compact heat exchanger having high pressure resistance, compactness and good heat transfer performance.

[0010]

Means for Solving the Problems In order to achieve the above object, the invention according to the stacked heat exchanger of the present invention comprises a stack of a plurality of plates, and a stack of plates A and B for flowing two heat exchange fluids. In the heat exchanger, the flow path of the fluid A and the fluid B
Are formed on the same plate.

In order to achieve the above object, another aspect of the invention relates to a laminated heat exchanger according to the present invention. The laminated heat exchanger comprises a plurality of plates laminated and A and B heat exchange fluids flowing therethrough. In the above, forming a flow path on both sides as a wavy bent structure of the plate, the upper convex portion and the lower concave portion, the upper concave portion and the lower convex portion are abutted and laminated, and are adjacent in the direction along the plate. In addition to forming a flow path, a flow path is formed in multiple stages also in the laminating direction, and fluid A and fluid B alternately flow in the flow path adjacent in the direction along the plate, and the flow path in the laminating direction of the plate Are fluids of the same type A or B.

In order to achieve the above object, a still further aspect of the stacked heat exchanger according to the present invention is to stack a plurality of plates having openings for fluid inflow or outflow, and A, B In a stacked heat exchanger that allows two heat exchange fluids to flow, forming groove-shaped channels on both upper and lower surfaces of the plate,
The upper convex part and the lower concave part, and the upper concave part and the lower convex part are abutted and laminated, and a flow path is formed adjacent to the direction along the plate, and a multi-stage flow path is also formed in the laminating direction. The fluid A and the fluid B alternately flow in the flow path adjacent in the direction along the plate, and the same type of fluid A or B flows in the flow path in the direction in which the plates are stacked. Openings are provided at both ends of the fluid passage, and a header is attached to the opening, and a header is attached between the headers, which communicates with the flow passage of the other fluid.

In order to achieve the above object, a still further aspect of the present invention according to the stacked heat exchanger of the present invention is that a plurality of plates having openings for fluid inflow or outflow are laminated, and A, B In a stacked heat exchanger that allows two heat exchange fluids to flow, groove-shaped channels are formed on the upper and lower surfaces of the plate, and the upper convex portion and the lower concave portion, and the upper concave portion and the lower convex portion are laminated by abutting each other. In addition, a flow path is formed adjacent to the direction along the plate, and a multi-stage flow path is also formed in the laminating direction. Fluid A and fluid B alternately flow in the flow path adjacent to the plate. And the same type of fluid of A or B flows through the flow path in the direction in which the plates are stacked,
An opening provided at one end of the plate and communicating with the one flow path and a header attached to the opening, and an opening communicating with the other flow path provided at the other end of the plate and a header attached to the opening. It is.

More specifically, one or more openings are formed at the bottom between the upstream end and the downstream end of one of the flow paths through which the fluid flows.

Further, a fine uneven structure is formed on the inner wall of at least one of the flow paths through which the fluid flows.

[0016]

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

FIGS. 1 to 8 show a first embodiment of the laminated heat exchanger of the present invention. FIG. 1 is a plan view of a plate used in the laminated heat exchanger of the present embodiment. Yes, Figure 2
Is a perspective view thereof. Laminate multiple plates 1
A, B The plate 1 is used for flowing two heat exchange fluids.
Is bent in a wave shape (the cross section is substantially U-shaped) so that the flow path of the fluid A and the flow path of the fluid B are formed on the same plate.

That is, the channels 3 and 5 are formed on both upper and lower surfaces, and the downward convex portion of the upper plate 1 and the upward concave portion of the lower plate 1, and the downward concave portion of the upper plate 1 and the upward convex portion of the lower plate 1 are abutted. The channels 3 and 5 are formed adjacent to each other in the direction along the plate 1. At the same time, channels 3 and 5 are formed in multiple stages also in the vertical direction of lamination,
Fluid A is supplied to the flow paths 3 and 5 adjacent to the direction along the plate 1.
And the fluid B alternately flow, so that the same type of fluid A or B flows in the vertical channel where the plates 1 are stacked.

The laminated heat exchanger of the present embodiment has a plate 1
Are stacked and joined by means of, for example, diffusion bonding, brazing, or the like. The plate 1 is formed by pressing a thin (for example, 0.5 mm) metal plate such as stainless steel or aluminum, and then forming a fine uneven structure 2 by cutting. The entire plate 1 can be manufactured by cutting. On the upper surface side of the plate 1, a plurality of channels 3 having a fine concave-convex structure 2 and a substantially U-shaped cross section are formed along the plate 1.
The flow path 3 is provided with openings 4 (two) located at both ends at arbitrary intervals and an opening 4 '(four) at the center of the flow path.

When a fluid such as a refrigerant, which has a high degree of gasification with a rise in temperature, flows through the opening 4 ′, the pressure is increased depending on the degree of gasification between the flow paths of the upper and lower plates 1. To mitigate the differences,
It is formed to equalize the flow rate of the refrigerant between the fluids.

For example, in the case of heat exchange between water and water, such a flow rate difference is hardly generated, so that it is not particularly necessary.
In heat exchange between the refrigerants, the opening works effectively in the flow path of the refrigerant.

On the other hand, the plate 1
, A plurality of flow paths 5 are formed so as to be adjacent to the flow paths 3 respectively. At both ends of the plate 1, openings 6 are provided at positions away from the flow paths 3, 5.

FIG. 3 is a detailed view of the fine concavo-convex structure 2, and FIG.
FIG. 2 is a partial cross-sectional view taken along line AA of FIG.

The fine uneven structure 2 shown in FIG. 1 has a cavity 7 formed on the inner wall surface of the flow channel 3 and has a cross section having an elliptical shape that increases from the surface to the inside. That is, the internal cross-sectional area is larger than the opening horizontal area. 4 and 5 are detailed views of another embodiment of the fine concavo-convex structure 2, FIG. 4 is a partial cross-sectional view, and FIG. 5 is a perspective view thereof.

The micro uneven structure 8 of the present embodiment has a structure in which a secondary groove 15 is cut out in a semi-circular shape at the upper part of a micro fin 14, and a conical cavity 9 is formed on the bottom surface. The fine uneven structure 2 may be formed by forming either the semicircular secondary groove 15 or the conical cavity 9.

In the present embodiment, the refrigerant (R410A
(Freon, etc.), and a single-phase fluid such as water is passed through the flow path 5. In a state where the plates 1 are stacked, the space between the flow path 3 and the flow path 5 and the space between the flow path 3 and the outside are sealed by being separated by a seal portion 16 (see FIG. 1) indicated by a broken line. FIG. 6 is an overall perspective view of the stacked heat exchanger, and FIG. 7 is a vertical cross-sectional view along the line AA in FIG. 6, in which the flow directions of the fluids A and B are indicated by solid arrows. FIG. 8 is a cross-sectional view taken along the line BB of FIG.
The header side end plate 1 is provided on both upper and lower end surfaces of the laminated plate 1.
0 and the back end plate 11 are attached. further,
The header-side end plate 10 is provided with headers 12, 12 'and headers 13, 13' which serve as an inlet or outlet for the fluid.

The fluid A (refrigerant) flowing through the flow path 3 and the flow path 5
The flow path is configured so as to be a completely opposed flow (a flow flowing in a facing direction) with the fluid B (water) flowing through the flow path. When the laminated heat exchanger of the present embodiment is used, for example, as a water-refrigerant heat exchanger of a chiller unit, the channel configuration is set as follows in consideration of the heat exchange performance and the influence of gravity.

As shown in FIG. 7, the heat exchanger is connected to the header 1.
When used as an evaporator, a refrigerant is allowed to flow from the lower header 12 so that the refrigerant 2 and 13 'are on the lower side and the headers 12' and 13 are on the upper side. , From the upper header 12 '. Water is allowed to flow in from the upper header 13 and to flow out from the lower header 13 '. Conversely, when used as a condenser, the refrigerant flows in from the upper header 12 and flows out from the lower header 12 '. Water is allowed to flow in from the lower header 13 and to flow out from the upper header 13 '.

It should be noted that making the flow completely countercurrent is particularly effective in improving the efficiency of the refrigeration cycle when a non-azeotropic mixed refrigerant such as R407C is used as the refrigerant.

That is, the fluid A flows in from the header 12 on the inlet side through the opening 4 and flows out of the header 12 ′ on the outlet side after flowing through the flow path 3. Fluid B is the header 1 on the inlet side
When the fluid A flows through the opening 6 and flows out of the header 13 ′ on the outlet side after flowing through the flow path 5, heat exchange is performed between the fluid A and the fluid B, and a phase change occurs in the fluid A.

In addition to the function of the header 12, the refrigerant undergoing phase change passes through an opening 4 '(represented by one in FIG. 7) provided in the middle of the flow path 3. Between the plates 1 so as to eliminate the pressure difference caused by the difference in the phase change state, and this movement keeps the refrigerant distribution in each flow path 3 good (that is, equalizes the pressure).

When two fluids A and B flow in the same plate 1 as in this embodiment, the force is applied to the flow path in the same plate 1 even if the pressure difference between the fluids A and B is large. 3
It acts on the boundary between the fluid and the flow path 5 (ie, acts in the horizontal direction in FIG. 8), and does not act in the direction in which the seal portion 16 between the plates 1 is peeled off. Therefore, a high pressure resistance can be obtained.

In the present embodiment, the fine uneven structure 2
Since it is formed by cutting, a complicated shape can be easily made.

In the above embodiment, the refrigerant flowing between the plates 1 can obtain good heat transfer performance by the action of the fine uneven structure 2.

That is, when used as an evaporation surface,
The refrigerant in the two-phase flow state spreads over almost the entire heat transfer surface along the microfins 14 by the capillary effect, and the entire heat transfer surface becomes wet, and the nucleate boiling is remarkably promoted by the function of the cavity 9. .

When used as a condensing surface, the refrigerant in the two-phase flow state has a surface tension acting so as to pull the liquid toward the gap side of the micro fin 14, and the secondary groove 15 is thin at the tip of the micro fin 14. It works to form a liquid film. With these functions, extremely good heat transfer performance can be obtained on the refrigerant side, and the evaporation performance or condensation performance of the refrigerant can be maximized, contributing to the downsizing of the stacked heat exchanger.

When the fluid is water, the cross-sectional dimension of the flow path 5 is greatly reduced due to the miniaturization of the size of the flow path 5 accompanying the compactness, and thus good heat transfer performance can be obtained.

FIGS. 9 and 10 show a second embodiment of the stacked heat exchanger of the present invention. FIG. 9 is a plan view of a plate 1 used in the stacked heat exchanger of the present embodiment. FIG. 10 is a perspective view thereof.

Also in this embodiment, the stacked heat exchangers are joined by means such as diffusion joining with the plates 1 stacked. In this embodiment, the plate 1 is formed by press-forming a thin metal plate and then forming a fine uneven structure 2 by cutting. Alternatively, the entire plate 1 may be formed by press working.

A plurality of channels 3 having a fine uneven structure 2 are formed on the plate 1, and an opening 4 ″ is formed at the lower end of the channel 3 as an inlet for the fluid A, and at the center of the channel. Are provided with openings 4 '(two) at arbitrary intervals.
An opening 4 is provided above the flow path 2 as an outlet at a position away from an end of the flow path 2. Further, a plurality of flow paths 5 are formed so as to be adjacent to the flow path 3, and openings 6 and 6 ′ are provided at both ends of the flow path 5 as inlets or outlets of the fluid B. Have been. The fine concavo-convex structure 2 is made in the same manner as that shown in FIG. 3 or FIG. 4 and FIG.

Also in this embodiment, a fluid which undergoes a phase change like a refrigerant flows through the flow path 3 and a single-phase fluid such as water flows through the flow path 5. In a state where the plates 1 are stacked, the seal between the flow path 3 and the flow path 5 and between the flow path 5 and the outside are separated and sealed.

The fluid A flows in through the opening 4 ″, flows upward in the flow path 3, and then flows out of the opening 4 on the outlet side. The fluid B flows in through the opening 6 ′ on the inlet side. Then, after flowing in the flow channel 5 in the downward direction as indicated by the arrow, it flows out of the opening 6 on the outlet side.At this time, heat exchange is performed between the fluid A and the fluid B, and a phase change occurs in the fluid A.

Since the refrigerant in the middle of the phase change can move in accordance with the pressure difference between the plates 1 through the central opening 4 of the flow path 3, the distribution of the refrigerant in each flow path 3 is kept good. Further, the heat of the refrigerant flowing between the plates 1 is favorably transferred by the action of the fine uneven structure 2.

When the fluid is water, the cross-sectional dimension is greatly reduced due to the miniaturization of the dimensions of the flow path 5 accompanying the downsizing, so that good heat transfer performance can be obtained.

Also in this embodiment, the two fluids A and B flow in the same plate 1 and the opening 4 is provided, so that even when the pressure difference between the two fluids A and B is large, the force is the same. 1 acts on the boundary between the flow path 3 and the flow path 5 and does not act in the direction in which the seal portion 16 between the plates 1 is peeled off. Therefore, high pressure resistance can be obtained without increasing the number of contact points between the plates as in the conventional case.
This also contributes to reducing the flow resistance in the flow paths A and B.

The laminated heat exchanger of the present invention has good heat transfer performance and is compact, so that the amount of refrigerant to be used can be reduced. This is effective for preventing global warming when using an alternative refrigerant such as an HFC refrigerant and improving safety when using a natural refrigerant such as an HC refrigerant or ammonia.

Further, it is possible to provide a refrigerating machine cycle such as a chiller unit which is effective for making the refrigerating cycle high-performance and compact and does not require a large installation area.

Further, similar effects can be obtained by using the laminated heat exchanger of this embodiment in a refrigeration / air-conditioning system. Further, the same effect can be obtained in the case of using a natural refrigerant in the laminated heat exchanger of this embodiment.

[0049]

According to the present invention, it has a high pressure resistance,
A laminated heat exchanger that is compact and has good heat transfer performance can be provided.

[Brief description of the drawings]

FIG. 1 is a plan view of a first embodiment of a plate used in a stacked heat exchanger of the present invention.

FIG. 2 is a perspective view of the plate of FIG. 1;

FIG. 3 is a partial cross-sectional view of the plate of FIG. 1 taken along line AA.

FIG. 4 is a partial cross-sectional view of another embodiment of the fine concavo-convex structure of the plate.

FIG. 5 is a perspective view of the embodiment of FIG.

FIG. 6 is an overall perspective view of an embodiment according to the stacked heat exchanger of the present invention.

FIG. 7 is a longitudinal sectional view taken along the line AA of FIG. 7;

FIG. 8 is a transverse sectional view taken along the line BB of FIG. 7;

FIG. 9 is a plan view of a second embodiment of the plate used in the stacked heat exchanger of the present invention.

FIG. 10 is a perspective view of the embodiment of FIG. 9;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Plate 2 ... Fine uneven structure 3, 5 ... Flow path 4, 4 ', 4 ", 6, 6' ... Opening 7, 9 ... Cavity 10 ... Header end plate 11 ... Back end plate 12, 12 ', 13, 13 'header 14 microfin 15 secondary groove 16 seal part

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Mitsugu Aoyama 390 Muramatsu, Shimizu-shi, Shizuoka F-term in Hitachi Air Conditioning Systems Shimizu Production Headquarters (reference) 3L103 AA05 AA11 BB42 CC02 CC28 DD03 DD55 DD57

Claims (6)

[Claims] 1. A stacked heat exchanger in which a plurality of plates are stacked and two heat exchange fluids A and B are flowed, wherein a flow path for the fluid A and a flow path for the fluid B are formed on the same plate. A stacked heat exchanger, comprising: 2. A stacked heat exchanger in which a plurality of plates are stacked and two heat exchange fluids A and B are flowed, wherein the plates are formed in a wave-like bent structure to form flow paths on both surfaces, The lower concave part, the upper concave part, and the lower convex part are laminated and abutted to form a flow path adjacent to the direction along the plate, and also form a multi-level flow path in the laminating direction, and follow the plate. Fluid A and fluid B
Flow alternately, and A
Alternatively, the laminated heat exchanger wherein the same type of fluid B flows. 3. A laminated heat exchanger in which a plurality of plates having openings for fluid inflow or outflow are laminated, and A and B heat exchange fluids are flowed. The upper convex part and the lower concave part, the upper concave part and the lower convex part are abutted and laminated, and a flow path is formed adjacently in a direction along the plate, and the laminating direction is also multi-layered. A flow path is formed, and fluid A and fluid B are provided in flow paths adjacent in the direction along the plate.
Flow alternately, and A
Or, the same type of fluid of B flows, and an opening is provided at both ends of the plate to communicate with the flow path of the one fluid, and a header is attached to the opening, and the other fluid is interposed between the headers. A stacked heat exchanger comprising a header connected to a flowing channel. 4. A laminated heat exchanger in which a plurality of plates having openings for fluid inflow or outflow are stacked and A and B heat exchange fluids are flowed, wherein groove-shaped flow paths are formed on upper and lower surfaces of the plate. The upper convex part and the lower concave part, the upper concave part and the lower convex part are abutted and laminated, and a flow path is formed adjacently in a direction along the plate, and the laminating direction is also multi-layered. A flow path is formed, and fluid A and fluid B are provided in flow paths adjacent in the direction along the plate.
Flow alternately, and A
Alternatively, the same type of fluid B flows, and an opening is provided at one end of the plate to communicate with the one flow path, and a header is attached to the opening, and the other end of the plate is connected to the other flow path. A stacked heat exchanger having an opening and a header attached to the opening. 5. The method according to claim 1, wherein one or more openings are formed at the bottom of the upstream end and the downstream end of one of the flow paths through which the fluid flows. A stacked heat exchanger as described. 6. The stacked heat exchanger according to claim 2, wherein a fine uneven structure is formed on an inner wall of at least one of the flow paths through which the fluid flows.