WO2014125566A1

WO2014125566A1 - Plate-type heat exchanger and refrigeration cycle device

Info

Publication number: WO2014125566A1
Application number: PCT/JP2013/053253
Authority: WO
Inventors: 伊東　大輔
Original assignee: 三菱電機株式会社
Priority date: 2013-02-12
Filing date: 2013-02-12
Publication date: 2014-08-21
Also published as: JPWO2014125566A1; CN203758092U

Abstract

A plate-type heat exchanger is provided with: a plurality of rectangular heat transfer plates (8) that comprise a passage hole serving as an inlet/outlet for a first fluid and a second fluid and that are stacked to form a first flow path through which the first fluid passes and a second flow path through which the second fluid passes; a first fluid-side inner fin (10) that is arranged in the first flow path and that accelerates heat transfer; and a second fluid-side inner fin (9) that is arranged in the second flow path and that accelerates heat transfer. The first fluid-side inner fin (10) comprises a protrusion that protrudes on the second flow path side along the direction in which the first fluid flows in the first flow path. In the heat transfer plates (8), the surface serving as the first flow path comprises a recess that matches the protrusion of the first fluid-side inner fin (10).

Description

Plate heat exchanger and refrigeration cycle apparatus

The present invention relates to a plate heat exchanger and a refrigeration cycle apparatus. In particular, the present invention relates to an inner fin type plate heat exchanger or the like.

Conventionally, a laminated heat exchanger in which a flow path is formed by a plurality of plates and an inner fin is inserted between the plates has been proposed for hot water supply and oil coolers (for example, see Patent Documents 1 and 2). . In addition, a plate-type evaporator has been proposed in which irregularities are provided in the fluid flow path to increase the heat transfer area (see, for example, Patent Document 3).

JP 2003-185375 A (page 5, FIG. 1) Japanese Unexamined Patent Publication No. 2003-294382 (page 4, FIG. 1) JP 2003-056990 A (page 5, FIG. 3)

However, the inner fin plate type heat exchanger as in Patent Document 1 has the following problems. For example, when heat exchange is performed between the first fluid (for example, refrigerant) and the second fluid (for example, water) and the first fluid is condensed from gas to liquid, a liquid film is formed on the wall surface of the fin on the second fluid side. It becomes easy to be done. Since the liquid film becomes a thermal resistance, the heat transfer coefficient has been lowered. Furthermore, when two types of fluids flow in adjacent flow paths, the shape of the flow paths is the same, so that only the characteristics of one of the fluids can be matched. Therefore, it has become impossible to design optimally in terms of heat transfer and strength.

Further, in the heat exchanger as in Patent Document 2, the grooves are inclined with respect to the flow direction and are formed intermittently. For this reason, it is possible to hold a condensed liquid fluid (hereinafter referred to as “condensate”), but the liquid repellency is poor and the condensate becomes a thermal resistance. When viewed from the fluid of the flat tube, the grooves are supported by the convex portions of each other, and the joining area of the adjacent heat transfer tubes is small and the strength is weak. And in the evaporator like patent document 3, a groove | channel is a cyclic | annular dent and is formed intermittently. Although the condensate can be retained, the liquid repellency is poor. In addition, the bonding area between adjacent heat transfer plates was small and the strength was weak.

From the above, it is an object of the present invention to obtain a plate heat exchanger or the like that can improve heat exchange performance and increase strength.

The plate type heat exchanger according to the present invention has a passage hole serving as an outflow inlet for the first fluid and an outflow inlet for the second fluid. A heat transfer plate forming a second flow path through which the second fluid passes, a first fluid-side inner fin disposed in the first flow path for promoting heat transfer, and disposed in the second flow path, for heat transfer The first fluid fin has a convex portion protruding from the first flow path side to the second flow path side, and the surface serving as the first flow path in the heat transfer plate is The first fluid side inner fin has a concave portion matched with the convex portion.

In the plate type heat exchanger according to the present invention, the first inner fin has a convex portion projecting to the second flow path side. For example, the first fluid side inner fin has a liquid generated when the first fluid is condensed. It can hold | maintain to a convex part, the expansion of the liquid film in a fin wall surface perimeter can be suppressed, liquid films other than a convex part can be made thin, and heat-transfer performance can be improved.

It is a figure which shows the structure of the plate type heat exchanger which concerns on Embodiment 1 of this invention. 2 is a perspective view showing a partial cross section of the heat exchanger according to Embodiment 1. FIG. FIG. 3 is a diagram in which an upper second fluid side inner fin 9 is removed from FIG. 2. FIG. 6 is a perspective view showing a partial cross section of a second fluid side inner fin 9. FIG. 4 is a perspective view showing a partial cross section of a heat transfer plate 8. It is the figure which remove | excluded the heat-transfer plate 8 from FIG. 3 is a perspective view showing a cross section of a part of the first fluid-side inner fin 10. FIG. It is the figure which expanded a part of cross section of the heat exchanger in this Embodiment shown in FIG. It is a figure which shows the structure of the refrigerating-cycle apparatus which concerns on Embodiment 4 of this invention.

Embodiment 1 FIG.
FIG. 1 is a view showing a plate heat exchanger according to Embodiment 1 of the present invention. In the following embodiments, an inner fin type plate heat exchanger (hereinafter referred to as a heat exchanger) will be described. Here, the upper side in each drawing will be described as the upper side, and the lower side will be described as the lower side. In the present embodiment, the first fluid is a refrigerant (for example, a fluid that changes phase by heat exchange), and the second fluid is water.

In one side plate 5 of the heat exchanger of the present embodiment, the first fluid inlet pipe 1, the first fluid outlet pipe 2, the first fluid outlet pipe 2, the first fluid outlet pipe 2, the first fluid outlet pipe 2, the first fluid outlet pipe 2, and the second fluid. A two-fluid inflow pipe 3 and a second fluid outflow pipe 4 are provided. The side plate 5 which does not have the first fluid inflow pipe 1, the first fluid outflow pipe 2, the second fluid inflow pipe 3 and the second fluid outflow pipe 4 does not have a passage hole. The side plate 5 serves to reinforce the heat exchanger and increase the strength.

The inner fin promotes heat transfer between the first fluid and the second fluid. In the present embodiment, the first fluid-side inner fin 10 disposed in the flow path (first flow path) through which the first fluid flows and the second flow path disposed in the flow path (second flow path) through which the second fluid flows. It has a fluid side inner fin 9. In the present embodiment, the first fluid side inner fin 10 and the second fluid side inner fin 9 through which the second fluid flows are different in shape. The first fluid side inner fin 10 and the second fluid side inner fin 9 will be described later.

A plurality of heat transfer plates 8 are stacked to form a flow path between the first fluid and the second fluid between the plates, and to exchange heat between the fluids. Here, the direction from the passage hole communicating with the fluid inflow pipe to the passage hole communicating with the outflow pipe is the major axis direction (longitudinal direction), and the orthogonal direction is the minor axis direction (short direction). In the heat exchanger of the present embodiment, the first flow path and the second flow path are formed by laminating one or a plurality of heat transfer plates 8 between the pair of side plates 5. The first fluid side inner fins 10 and the second fluid side inner fins 9 are alternately sandwiched between the heat transfer plates 8. The heat transfer plate 8 of the present embodiment has irregularities corresponding to the shapes of the first fluid side inner fin 10 and the second fluid side inner fin 9. In addition, since the first fluid-side inner fin 10 and the second fluid-side inner fin 9 have different heights (directions perpendicular to the direction in which the fluid flows), two types of heat transfer plates 8 matched to the height are used. have. And it has a passage hole corresponding to the 1st fluid inflow pipe 1, the 1st fluid outflow pipe 2, the 2nd fluid inflow pipe 3, and the 2nd fluid outflow pipe 4. Here, as shown in FIG. 1, let the flow direction of the first fluid be X and let the flow direction of the second fluid be Y. From FIG. 1, in the flow path formed in the heat transfer plate 8, the flow direction of the refrigerant in the first fluid and the second fluid is the opposite flow.

FIG. 2 is a perspective view showing a partial cross section of the heat exchanger according to Embodiment 1 of the present invention. In FIG. 2, the heat transfer plate 8, the second fluid side inner fin 9, the heat transfer plate 8, the first fluid side inner fin 10, the heat transfer plate 8, and the second fluid side inner fin 9 are stacked in this order from the lower side. The figure is shown.

3 is a view obtained by removing the upper second fluid side inner fin 9 from FIG. FIG. 4 is a perspective view showing a cross section of a part of the second fluid side inner fin 9. FIG. 5 is a perspective view showing a partial cross section of the heat transfer plate 8. FIG. 6 is a view obtained by removing the heat transfer plate 8 from FIG. FIG. 7 is a perspective view showing a partial cross section of the first fluid-side inner fin 10.

FIG. 8 is an enlarged view of a part of the cross section of the heat exchanger in the present embodiment shown in FIG. As shown in FIGS. 7 and 8, in the heat exchanger of the present embodiment, at least the first fluid-side inner fin 10 has a protruding portion that protrudes toward the second flow path. And according to the convex part of the 1st fluid side inner fin 10, as shown in FIG.3 and FIG.5, an unevenness | corrugation is also formed in the heat-transfer plate 8. FIG. The concave portion of the heat transfer plate 8 corresponds to the convex portion of the first fluid-side inner fin 10. For this reason, the convex part when viewed from the first flow path side becomes a concave part on the second fluid side. Since the first fluid-side inner fin 10 has the convex portion, when the first fluid passes through the first flow path and condenses, a liquid film (condensed liquid film) formed by condensation is converted into the first fluid-side inner fin 10. It is made to concentrate on the convex part. For this reason, the condensate film formed on the wall surface of the first fluid-side inner fin 10 other than the convex portion and the wall surface of the heat transfer plate 8 can be thinned, and the heat transfer coefficient can be improved.

Here, as shown in FIGS. 3 and 4, in the present embodiment, the second fluid-side inner fin 9 is also formed with a convex portion. Here, the arrangement of the inner fins may be parallel or orthogonal to the fluid flow direction. In particular, in order to improve the liquid spillability, the heat transfer plate 8 and the protrusions formed on each inner fin may be formed so as to be linear along the fluid flow direction. The convex portion is formed from the passage hole communicating with the first fluid inflow pipe 1 toward the passage hole communicating with the first fluid outflow pipe 2 along the fluid flow direction (long axis direction). The first fluid that has been condensed and turned into a liquid is concentrated on the convex portion and flows down, so that the liquid spillability from the fin wall surface is improved and the heat transfer rate is improved. On the other hand, when the refrigerant evaporates, in the case of a single-phase fluid, the flow of the fluid is agitated at the convex portion, and heat transfer is improved. For this reason, the amount of heat exchange can be increased. For example, at the time of evaporation, the heat transfer coefficient is improved by holding the condensate in the convex portion of the first fluid-side inner fin 10 and activating nucleate boiling between adjacent bubbles. For this reason, regardless of two-phase or single-phase, the convex portions protruding into the flow paths promote local disturbance of the fluid, and compared to the case where the inner fin and heat transfer plate surfaces are flat, The heat transfer coefficient can be improved. Moreover, by forming convex portions on the first fluid-side inner fin 10 and the second fluid-side inner fin 9, it is possible to increase the effective heat transfer area and further increase the amount of heat exchange.

Moreover, since the convex portions of the first fluid-side inner fin 10 and the second fluid-side inner fin 9 can be fitted by forming the heat transfer plate 8 to be uneven, an offset type heat exchange having a flat surface is possible. Compared with a vessel, the bonding strength can be greatly improved. Thereby, the plate | board thickness of the side plate 5 and the heat-transfer plate 8 can be made thinner than the conventional offset type heat exchanger, and a heat exchanger can be manufactured cheaply.

From the above, it is possible to achieve both heat transfer and strength improvement regardless of the fluid flow state. For this reason, for example, a high-pressure refrigerant such as carbon dioxide can be used. In addition, by forming the irregularities of the heat transfer plate 8 along the flow of the fluid, high heat exchange performance can be achieved even in simultaneous cooling and heating operations and defrosting operations in which the flow directions of the first fluid and the second fluid change. Can be realized.

Embodiment 2. FIG.
Although not particularly shown in the first embodiment, the arrangement of the heat transfer plate 8 having a convex portion and a concave portion will be described in the present embodiment. For example, in accordance with the convex portion of the first fluid-side inner fin 10, as shown in FIG. 5 and the like, the convex portions (between concave portions) are arranged at equal intervals in the short axis direction.

For example, as shown in FIGS. 7 and 8, the dimension s, which is the interval between the convex portions of the first fluid-side inner fin 10, and the interval t between the convex portions of the heat transfer plate 8 are each in the minor axis direction. Are arranged at equal intervals with the same length. Thereby, the unevenness | corrugation of the 1st fluid side inner fin 10 and the unevenness | corrugation of the heat-transfer plate 8 corresponding to the 1st fluid side inner fin 10 can be formed with the same kind of metal mold | die. Similarly, if the interval between the convex portions of the second fluid side inner fin 9 and the interval between the convex portions of the heat transfer plate 8 are equally spaced in the minor axis direction, The unevenness of the two-fluid-side inner fins 9 and the unevenness of the heat transfer plate 8 corresponding to the second fluid-side inner fins 9 can be formed by the same type (two types in total, one type each). For example, in the example shown in FIG. 8, the interval between the convex portions of the first fluid-side inner fin 10 and the interval between the convex portions of the second fluid-side inner fin 9 are the same. There is no need to make the heat transfer plate 8. For this reason, in addition to the effect of Embodiment 1, a heat exchanger can be obtained more inexpensively.

Embodiment 3 FIG.
In the present embodiment, the convex portion of the first fluid-side inner fin 10 will be described. As shown in FIGS. 7 and 8, the convex portions and concave portions of the first fluid-side inner fin 10 are arranged in a staggered manner. For this reason, for example, in the first fluid-side inner fin 10 in which the protrusions are formed in rows with respect to the flow direction of the refrigerant, the unevenness of the heat transfer plate 8 can be fitted so that a plurality of rows of protrusions can be fitted. Form. In FIG. 8 etc., the unevenness | corrugation of the heat-transfer plate 8 is formed so that the convex part for 2 rows of the 1st fluid side inner fin 10 can be fitted by one recessed part.

This makes it possible to increase the heat transfer coefficient and heat transfer area of the first fluid compared to the second fluid. However, if the inner fin is formed in such a shape, the pressure loss increases. Therefore, this is effective when a fluid having a restriction on pressure loss is used as the second fluid, and a fluid that has no restriction on the pressure loss and can prioritize heat transfer performance is used as the first fluid.

For example, as shown in FIG. 8, when the convex portion of the first fluid-side inner fin 10 is set to s1 that is ½ of the dimension s, the convex portion of the first fluid-side inner fin 10 becomes the concave portion of the heat transfer plate 8. It will fit. For this reason, the 1st fluid side inner fin 10 and the heat-transfer plate 8, and the 2nd fluid side inner fin 9 and the heat-transfer plate 8 can each be created with 1 type (total 3 types) metal mold | die. Therefore, it is excellent in productivity.

Although the case where two convex portions of the first fluid-side inner fin 10 are arranged in the concave portion on the second fluid side has been described as an example, the first fluid-side inner fin 10 may be used as long as pressure loss and manufacturing restrictions of the first fluid are not exceeded. The number of convex portions may be divided.

Further, as shown in FIG. 7, the first fluid-side inner fin 10 is arranged so that the direction u is the flow direction X, but may be arranged so that the direction s is the flow direction X. Similar effects can be obtained. Similarly, as shown in FIG. 4, the second fluid-side inner fin 9 is arranged so that the direction of v is the flow direction Y, but is arranged so that the direction of t is the flow direction X. The same effect can be obtained.

Embodiment 4 FIG.
FIG. 9 is a diagram showing a configuration of a refrigeration cycle apparatus according to Embodiment 4 of the present invention. In the refrigeration cycle apparatus of FIG. 9, a refrigerant circuit (refrigerant circulation circuit) is configured by connecting a compressor 21, a condenser (including a gas cooler) 22, an expansion device 23, and an evaporator 24. In addition, the blower 25 drives the blower motor 26 to form an air flow in order to promote heat exchange between the refrigerant passing through the evaporator 24 and the air.

Compressor 21 sucks in refrigerant, compresses it, discharges it in a high temperature / high pressure state. Here, for example, it may be configured by a compressor of a type that can control the number of revolutions by an inverter circuit or the like and adjust the discharge amount of the refrigerant.

The condenser 22 having the heat exchanger described in the first embodiment or the like performs heat exchange between, for example, water (second fluid) flowing through the water circuit 27 and the refrigerant (first fluid) to condense the refrigerant. To make a liquid refrigerant (condensed liquid).

Further, the expansion device 23 expands the refrigerant by decompressing it. For example, it is constituted by a flow rate control means such as an electronic expansion valve, but may be constituted by an expansion valve having a temperature sensing cylinder, a refrigerant flow rate adjustment means such as a capillary tube (capillary), or the like. The evaporator 24 evaporates the refrigerant by exchanging heat with air or the like to form a gas (gas) -like refrigerant (evaporation gasification). Although not particularly shown in FIG. 9, for example, the heat exchanger described in Embodiments 1 to 3 can be used for the evaporator 24.

In the refrigeration cycle apparatus of the fourth embodiment, heat transfer performance can be improved by using the heat exchanger described in the first to third embodiments. By improving the heat transfer performance, an energy-efficient and energy-saving refrigeration cycle apparatus can be obtained.

Here, each energy efficiency in cooling and heating is as follows.
Heating energy efficiency = indoor heat exchanger (condenser) capacity / total input Cooling energy efficiency = indoor heat exchanger (evaporator) capacity / total input

Next, operations and the like in each component device of the refrigeration cycle apparatus will be described based on the flow of the refrigerant circulating in the refrigerant circuit. First, the compressor 21 sucks the refrigerant, compresses it, and discharges it in a high temperature / high pressure state. The discharged refrigerant flows into the condenser 22. The condenser 22 performs heat exchange between the water flowing through the water circuit 27 and the refrigerant to condense and liquefy the refrigerant. The condensed and liquefied refrigerant passes through the expansion device 23. The expansion device 23 depressurizes the condensed and liquefied refrigerant that passes therethrough. The decompressed refrigerant flows into the evaporator 24. The evaporator 24 exchanges heat between the air supplied from the blower 25 and the refrigerant, and evaporates the refrigerant. The compressor 21 sucks the evaporated gas refrigerant.

Here, the refrigeration cycle apparatus described above includes HCFC (R22) and HFC (R116, R125, R134a, R14, R143a, R152a, R227ea, R23, R236ea, R236fa, R245ca, R245fa, R32, R41, RC318, etc. Several mixed refrigerants R407A, R407B, R407C, R407D, R407E, R410A, R410B, R404A, R507A, R508A, R508B, etc.), HC (butane, isobutane, ethane, propane, propylene, etc.) Refrigerant), natural refrigerant (several mixed refrigerants such as air, carbon dioxide, and ammonia), low GWP refrigerant such as HFO1234yf, and several mixed refrigerants of these refrigerants. In particular, the effect can be achieved more efficiently in R410A, R410A, and R32 whose design pressure and physical property values are close.

Here, with respect to the heat exchanger and the refrigeration cycle apparatus described in the first embodiment and the second embodiment, the refrigerant and the oil dissolve, such as mineral oil, alkylbenzene oil, ester oil, ether oil, and fluorine oil. The effect can be achieved with any refrigeration oil, whether or not.

The present invention is not particularly limited to the above-described embodiments, and can be combined as appropriate. Moreover, as an application example of the present invention, for example, the present invention can be used for many industrial and household equipment equipped with a plate heat exchanger such as air conditioning, power generation, and food sterilization equipment.

1 1st fluid inflow pipe, 2nd 1st fluid outflow pipe, 3rd 2nd fluid inflow pipe, 4th 2nd fluid outflow pipe, 5 side plate, 8 heat transfer plate, 9 2nd fluid side inner fin, 10 1st fluid side Inner fin, 21 compressor, 22 condenser, 23 throttling device, 24 evaporator, 25 blower, 26 blower motor, 27 water circuit, X first fluid flow direction, Y second fluid flow direction.

Claims

A first flow path through which the first fluid passes and a second flow through which the second fluid passes by having a plurality of passage holes that serve as the first fluid outflow inlet and the second fluid outflow inlet. A heat transfer plate forming a path;
A first fluid-side inner fin disposed in the first flow path to promote heat transfer;
A second fluid-side inner fin that is disposed in the second flow path and promotes heat transfer;
The first fluid side inner fin has a convex portion protruding from the first flow path side to the second flow path side,
In the heat transfer plate, the surface serving as the first flow path is a plate heat exchanger having a concave portion matched with the convex portion of the first fluid-side inner fin.
The plate heat exchanger according to claim 1, wherein the recesses of the heat transfer plate are arranged at equal intervals in a direction orthogonal to a direction in which the first fluid flows in the first flow path.
The convex portions of the first fluid-side inner fins are formed in a row along the direction in which the first fluid flows in the first flow path,
The plate-type heat exchanger according to claim 1 or 2, wherein convex portions for a plurality of rows of the first fluid-side inner fins are fitted into one concave portion of the heat transfer plate.
A compressor that compresses and discharges the refrigerant; a condenser that condenses the refrigerant by heat exchange; a throttling device that depressurizes the refrigerant related to condensation; and A refrigerant circuit is configured by connecting a pipe to an evaporator that evaporates
A refrigeration cycle apparatus, wherein at least one of the evaporator and the condenser includes the plate heat exchanger according to any one of claims 1 to 3.