JP2007333353A - Micro-channel integrated type laminated structure heat exchanger for super critical refrigerant - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To materialize a heat exchanger comprising micro scale minute channels for super critical refrigerant having pressure resistance against CO<SB>2</SB>getting under a super critical condition at 80 atmospheres or higher or chlorofluorocarbon refrigerant getting under a super critical condition at 40 atmospheres or higher, materializing high overall heat transfer coefficient, and having short start time as a heat exchanger without increasing friction loss. <P>SOLUTION: Many metal plates 6 having minute channels 3, 5 formed on a surface thereof are joined by using diffused junction to form the heat exchanger having an integrated structure having many minute channels laminated. Consequently, the heat exchanger has a high pressure resistant structure enduring against high pressure, and enables the super critical CO<SB>2</SB>refrigerant to flow at high speed by that, and become a compact structure having heat transfer quantity exceeding that of a former type heat exchanger as the result. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a heat exchanger, and more particularly, to a microchannel integrated layered structure heat exchanger for a supercritical refrigerant suitable for a heat pump using a supercritical refrigerant.

  Currently, the development of small and distributed energy systems such as cogeneration systems using micro gas turbines and fuel cells is actively underway, and there is a great demand for miniaturization suitable for home use and on-vehicle use. Development for is underway.

  In conventional heat exchangers, those that greatly exceed the scale of micro gas turbines and fuel cell bodies are used. If the heat exchangers are downsized, the efficiency of the heat exchangers decreases, and micro gas turbines and fuel cells are reduced. There is a problem that the efficiency of a single unit is significantly reduced. As an example of a conventional heat exchanger, a plate-type heat exchanger is known in which a predetermined number of plates are stacked and welded together (see Patent Document 1).

  As described above, in order to improve efficiency in a small energy system, it is indispensable to use a high-efficiency heat exchanger. It becomes an extremely large device and cannot be made into an original small energy system.

  For this reason, research on heat exchangers using fine flow paths has been conducted, but leakage from the formed flow path joints occurs when an actual device is used in the conventional technology. There is a problem that it can be used only under low pressure conditions and cannot apply high pressure and high flow velocity.

  By the way, as the basic theory of heat transfer engineering, the smaller the flow path, the more uniformly it can be heated and cooled, but if the flow path is fine and short, the heat exchangeable heat is limited. Become. Therefore, if a high flow rate can be made to flow through a large number of fine flow paths, it is expected that the required efficiency can be obtained by increasing the amount of exchange heat.

  When this heat transfer theory is applied to a heat exchanger, a highly efficient heat exchanger, even if it is small, is first a laminated structure having many fine channels. Second, a high flow rate is applied. It is a necessary condition that the structure has a high breakdown voltage.

  On the other hand, in a heat exchanger having a micro-channel structure currently manufactured by MEMS (micro electro mechanical system small electromechanical system), etc., it can be used at high pressure due to leakage from the formed channel junction. There is a problem that it is impossible.

  In order to solve these problems, the present inventors have already developed a small, high-priced element that is an essential element for realizing a small distributed energy system such as a cogeneration system using a micro gas turbine or a fuel cell. As an efficient heat exchanger, an integrated laminated heat exchanger has been proposed (see Patent Document 2).

The outline of this integrated laminated structure heat exchanger is a device with an integrated structure in which a number of metal plates with fine channels formed on the surface are joined together using diffusion bonding, and a number of fine channels are stacked. It is.
JP 2000-356491 A JP 2005-282951 A

Incidentally, for the heat pump, in recent years, from the viewpoint of preventing global warming, CFC, instead of the conventionally utilized once it was refrigerant, supercritical CO ₂ refrigerant Pump utilize CO ₂ as a refrigerant in a supercritical state is noticed ing.

However, since it has to be utilized in a compressed state CO ₂ to the supercritical pressure (80 atm) or more high pressure to the CO ₂ in a supercritical state, heat exchanger for passing therethrough is destroyed, There is a problem that it is difficult to put into practical use. Also, although a fluorocarbon refrigerant heat pump that uses a fluorocarbon refrigerant compressed to a supercritical pressure (40 atm) or more has been attracting attention, there is also a problem that it is difficult to put into practical use.

The present inventors proceeded with the practical development of the integrated laminated structure heat exchanger of Patent Document 2 described above, and for that purpose, pressure resistance test (relationship between flow rate and pressure loss), heat passage rate test (relationship between flow rate and heat passage rate). When performing a performance test such as a start-up test (time to reach a steady operation state), this integrated laminated structure heat exchanger compresses CO ₂ or a fluorocarbon refrigerant to a supercritical pressure or higher. The present inventors have found that it is extremely useful as a heat exchanger for the CO ₂ or CFC refrigerant heat pump to be used.

INDUSTRIAL APPLICABILITY The present invention is a supercritical refrigerant that is extremely useful as a heat exchanger for a heat pump having a pressure resistance against CO _{2 that is} supercritical at 80 atmospheres or more or a fluorocarbon refrigerant that is supercritical at 40 atmospheres or more. It is an object of the present invention to realize an integrated laminated structure heat exchanger.

  In order to solve the above-mentioned problems, the present invention is such that the plurality of metal plates are formed in an integrated laminated structure so that the heating flow path and the cooling flow path formed in each of the plurality of metal plates do not communicate with each other. In the integrated laminated structure heat exchanger, each of the plurality of metal plates has one of a heating channel and a cooling channel formed on each surface, and a heating channel and a back surface with respect to the surface. The other of the cooling channels is formed, and the cross-sectional dimensions of the heating channel and the cooling channel are 10 to 1000 μm in vertical and horizontal dimensions, respectively. provide.

  The plurality of metal plates are formed in an integrated laminated structure by diffusion bonding, and the joining surface of the laminated structure has the same strength as the metal plate, and is in a supercritical state in the heating channel and the cooling channel. It is preferable that the structure has a pressure resistance capable of flowing a high-pressure fluid.

  It is preferable that the heating channel and the cooling channel have a configuration in which a fluid is flowed at a high speed and heat exchange is possible by condensing or boiling.

  The heating channel or the cooling channel is used for a heat pump having a pressure resistance against a carbon dioxide refrigerant that becomes supercritical at 80 atmospheres or more or a fluorocarbon refrigerant that becomes a supercritical state at 40 atmospheres or more. It is preferable that the configuration be

  The heating channel or cooling channel is a heat generated by boiling and condensation of a carbon dioxide refrigerant that becomes supercritical at 80 atm or higher or a fluorocarbon refrigerant that becomes supercritical at 40 atm or higher. A configuration having a microchannel structure used for a heat pump with movement is preferable.

  The integrated laminated structure heat exchanger of the present invention is 1/10 to 1/100 the size of a conventional heat exchanger having the same performance, and is configured to be used as a heat exchanger of a refrigeration air conditioner. Is preferred.

  The integrated laminated structure heat exchanger of the present invention is used in a cogeneration system using a micro gas turbine or a fuel cell, and has a configuration that can be used with high efficiency as a heat exchanger for waste heat utilization. preferable.

  The integrated laminated structure heat exchanger according to the present invention preferably has a configuration in which the vertical and horizontal dimensions are 10 to 1000 μm and enables high-performance heat exchange that can be used in a small distributed energy system.

In order to solve the above-mentioned problems, the present invention is configured such that the plurality of metal plates are laminated and diffusion-bonded to each other so that the heating channel and the cooling channel formed in each of the plurality of metal plates do not communicate with each other. An integrated laminated structure heat exchanger for a supercritical CO ₂ refrigerant having a laminated structure, wherein each of the plurality of metal plates has one of a heating channel and a cooling channel formed on each surface. The other of the heating channel and the cooling channel is formed on the back surface with respect to the front surface, and the cross-sectional dimensions of the heating channel and the cooling channel are microscales in the vertical and horizontal dimensions, respectively. A supercritical CO ₂ refrigerant-integrated laminated heat exchanger is provided in which a supercritical CO ₂ refrigerant is used in a heating channel or a cooling channel.

In order to solve the above-mentioned problems, the present invention provides an integrated laminated structure in which the plurality of metal plates are laminated and diffusion-bonded to each other so that heating channels and cooling channels formed in the plurality of metal plates do not communicate with each other. In the integrated laminated structure heat exchanger for a supercritical CO ₂ refrigerant, the plurality of metal plates each have one of a heating channel and a cooling channel formed on the front surface or the back surface. The cross-sectional dimensions of the heating channel and the cooling channel are microscales in the vertical and horizontal dimensions, respectively, and the supercritical CO ₂ refrigerant is used in the heating channel or the cooling channel. An integrated laminated structure heat exchanger for supercritical CO ₂ refrigerant is provided.

  An integrated laminated structure heat exchanger for a supercritical refrigerant according to the present invention comprises a plurality of metal plates, each having a microscale having a cross-sectional dimension of microscale on the surface, and an integrated laminated structure using diffusion bonding. By doing so, a structure in which a large number of microchannels (microchannels) are crossed and stacked without communicating with each other has the following effects.

(1) A high pressure resistant structure capable of flowing a high-pressure supercritical CO ₂ refrigerant or a supercritical chlorofluorocarbon refrigerant at a high flow rate can be realized.
(2) The amount of heat exchange can be increased, high heat exchange efficiency can be achieved, and a compact configuration can be achieved.
(3) The start-up time for rising to a steady state is short.

  The best mode for carrying out an integral laminated structure heat exchanger for a supercritical refrigerant according to the present invention will be described based on examples with reference to the drawings.

(Characteristic)
The outline of the integrated laminated structure heat exchanger for supercritical refrigerant according to the present invention (hereinafter, simply referred to as “heat exchanger”) is a micro-scale flow channel (for example, 10 to 1000 μm) in vertical and horizontal cross-sectional dimensions (for example, 10 to 1000 μm). In the present invention and in the present specification, it is called “microchannel”). A plurality of different or similar metal plates are laminated by diffusion bonding to form an integrated laminated structure, so that even a high pressure can be obtained. It is an integrated laminated heat exchanger for supercritical CO ₂ refrigerant that can withstand high efficiency.

  The joint surface of this laminated structure is formed so as to have the same strength as the metal plate in the case of the same kind of metal plate, and the same strength as any one of them in the case of a different kind of metal plate.

The present invention is characterized by its use as a heat exchanger for a supercritical refrigerant that is incorporated and used as a heat exchanger for a heat pump that uses a supercritical CO ₂ refrigerant or a supercritical chlorofluorocarbon refrigerant. The efficiency of the entire system can be improved, which helps to solve global environmental problems. The characteristics of the heat exchanger according to the present invention in terms of its characteristics are as follows.

(1) Pressure resistance is required even when a high-pressure supercritical CO ₂ refrigerant of 80 atm or higher is passed through the heat exchanger. The heat exchanger of the present invention is configured by laminating micro flow channels with micro and vertical dimensions that intersect each other. However, if there is no pressure resistance, the flow channel is formed when a high-pressure fluid flows in one flow channel. It expands and deforms, and this deformation impedes the flow of the other channel that intersects each other. The heat exchanger according to the present invention is configured such that even if a high-pressure fluid flows through one flow path, the flow of the other flow path that intersects each other is not hindered.

(2) Even when a high-pressure fluid such as a supercritical CO ₂ refrigerant or a supercritical chlorofluorocarbon refrigerant is caused to flow through a micro-scale microchannel, there is a concern that friction loss increases and heat transfer rate is reduced. The heat exchanger of the present invention does not cause such a concern, and has high flow characteristics and heat transfer characteristics (heat exchange amount, heat exchange rate), and the start-up time as a heat exchanger Is also a short configuration.

(Constitution)
FIG. 1 is a diagram illustrating an embodiment of a heat exchanger according to the present invention. Fig.1 (a) is a perspective view which shows the external appearance of the heat exchanger 1 of this Example, FIG.1 (b) is the top view. This heat exchanger 1 has an integral rectangular structure as an overall configuration of the appearance.

  As shown in FIGS. 1A and 1B, the flow path extends in the front-rear direction (longitudinal direction, y direction in the illustrated example) and in the left-right direction (lateral direction, x direction in the illustrated example). Although there are flow paths, for convenience of explanation, the flow path extending in the front-rear direction (longitudinal direction) is referred to as a cooling flow path (flow path through which a low-temperature medium flows) 3, and the flow path extending in the left-right direction (lateral direction) is heated. A path (flow path through which a high-temperature medium flows) is defined as 5.

  The heat exchanger 1 includes a group (cooling flow path group 2) composed of a large number of fine (for example, 10 to 1000 μm) cooling flow paths 3 that are arranged in parallel in the same plane and whose vertical and horizontal dimensions are microscales, A plurality of fine heating channels 5 (heating channel groups 4) alternately arranged in the vertical direction are arranged in parallel in the same plane and are composed of a large number of fine (for example, 10 to 1000 μm) heating channels 5 with micro dimensions in the vertical and horizontal dimensions. It has a laminated structure.

  1 (a) and 1 (b), in each cooling flow path group 2, a large number of fine cooling flow paths 3 extending in one direction (in the direction of the arrow y in the example of the figure) are spaced at regular intervals in the x direction. It is installed side by side. Similarly, in each heating channel group 4, a number of fine heating channels 5 extending in one direction (in the direction of the arrow x in the example in the figure) are arranged in parallel in the y direction at regular intervals.

  In the heat exchanger 1 of this embodiment, the cooling flow path 3 of the cooling flow path group 2 and the heating flow path 5 of the heating flow path group 5 extend in the xy direction, and as shown in FIG. Although formed so as to extend in an orthogonal direction, the multiple cooling flow paths 3 of the cooling flow path group 2 and the multiple heating flow paths 5 of the heating flow path group 4 are arranged vertically so as not to cross each other and communicate with each other. Laminated and arranged with the position shifted in the direction.

  In the heat exchanger 1 of this embodiment, the cooling flow path 3 of the cooling flow path group 2 and the heating flow path 5 of the heating flow path group 4 extend in directions orthogonal to each other as shown in FIG. However, this is merely an example, and the cooling flow path 3 and the heating flow path 5 may cross each other at any angle (not necessarily in communication with each other) even if they are not orthogonal to each other. It may be configured to extend as is. For example, they may be formed so as to intersect with each other at an angle α as shown in FIG. 1C, or may be parallel to each other as long as the cooling channel and the heating channel can be arranged. In short, the cooling flow path 3 and the heating flow path 5 may be extended so that the refrigerants flowing through the cooling flow path 3 and the heating flow path 5 are parallel flow or counter flow.

  Furthermore, in the heat exchanger 1 of this embodiment, the cooling flow path 3 and the heating flow path 5 are each formed linearly, but may be a curved line instead of a straight line. However, since the load on the pump that sends the cooling and heating fluid increases as the flow resistance increases, energy loss increases. Considering these points, the shapes and structures of the cooling flow path 3 and the heating flow path 5 are Should be designed.

  The configuration of the heat exchanger 1 according to the present invention shown in FIG. 1 will be described in more detail with reference to FIGS. The heat exchanger 1 according to the present invention has an integral laminated structure in which a plurality of metal plates having fine channels formed on the surface thereof are diffusion bonded.

  FIG. 2 is a view for explaining the structure of one metal plate 6 (metal thin plate) that is a component of the heat exchanger 1, FIG. 2 (a) is a perspective view, and FIG. 2 (b) is a front view. FIG. 2 (c) is a side view.

  As shown in FIGS. 2A to 2C, the upper surface 7 of the metal plate 6 has a large number of fine dimensions (for example, 10 to 1000 μm) in the vertical direction (front-rear direction) of the vertical and horizontal dimensions. A flow path (for the sake of explanation, referred to as “cooling flow path 3”) is formed, and the lower surface 8 of the metal plate 6 has a large number of microscopic scales (for example, vertical and horizontal dimensions) , 10 to 1000 μm) channels (for convenience, referred to as “heating channels 5”) are formed.

  The metal plate 6 having the structure shown in FIG. 2A is made of a metal plate 6 made of different materials, for example, two types of A-type metal plates made of different materials A and B, respectively. A plurality of 6A and B type metal plates 6B are formed and prepared. Of course, the same type of metal plate may be used, but in this embodiment, a description will be given using different types of metal plates.

  2D to 2G are views for explaining a laminated structure in which metal plates 6 that are constituent elements of the heat exchanger 1 are laminated. In order to simplify the description, a structure in which a total of four metal plates 6 of an A type metal plate 6A and a B type metal plate 6B are alternately laminated in the vertical direction will be described.

  FIG.2 (d) shows the front view of the four metal plates 6 which should be laminated | stacked, and FIG.2 (e) shows the side view. 2 (f) and 2 (g) show a front view and a side view of the heat exchanger 1 to be manufactured. By the way, although the A-type metal plate 6 and the B-type metal plate 6 are made of different materials, their structures are completely the same including the flow paths formed on the upper and lower surfaces of each.

  As shown in FIGS. 2 (d) and 2 (e), the upper and lower surfaces of the A type metal plate 6 and the B type metal plate 6 that are adjacent to each other are alternately turned upside down. Place and abut. For example, the A type metal plate 6 </ b> A is formed so that the laterally extending heating channel 5 formed in the B type metal plate 6 </ b> B matches the laterally extending heating channel 5 formed in the lower surface of the A type metal plate 6 </ b> A. The lower surface of the metal plate 6A and the upper surface of the B type metal plate 6B face each other and come into contact with each other.

  As described above, when the upper surface of the B-type metal plate 6B is in contact with the lower surface of the A-type metal plate 6A and the pressure is applied while heating in a vacuum atmosphere, the A-type metal plates 6A of different materials are used. And atomic diffusion occurs at the interface 9 between the materials of the B type metal plate 6B, and diffusion bonding can be performed as if they were the same material in terms of molecular structure.

  Next, the bottom surface of the B type metal plate 6B is aligned with the cooling channel 3 formed on the A type metal plate 6A and the cooling channel 3 on the bottom surface of the B type metal plate 6B. The top surface of the A-type metal plate 6A is brought into contact with and similarly diffusion-bonded. In the same manner, the heat exchanger 1 can be formed by sequentially stacking a plurality of metal plates 6 adjacent to each other by diffusion bonding.

  FIG. 3A is a top view of the heat exchanger unit 11 in which the heat exchanger 1 according to the present invention formed as described above is inserted and packaged in the housing 10 of the heat exchanger. It is. In front and rear of the housing 10, a vertical direction (front-rear direction) flow path entrance 12 is provided, and on the left and right sides of the housing 10 lateral direction (left and right direction) flow path entrances 13 are provided. Yes. In addition, the flow paths in the vertical direction (front-rear direction) and the left-right direction are appropriately selected as the cooling flow path 3 and the heating flow path 5 according to the use, structure, etc. of the entire apparatus to which the heater is attached.

  FIG.3 (b) shows the cut surface cut | disconnected diagonally seeing from the heat exchanger unit upper direction shown to Fig.3 (a), The partial enlarged view of the cut surface is shown in FIG.3 (c). The cut surface of the heat exchanger unit 11 shown in FIGS. 3B and 3C includes a front-rear direction (vertical direction) flow path and a lateral direction used as the cooling flow path 3 and the heating flow path 5, respectively. The cut-out of the (left-right direction) flow path is shown.

  Next, specific specification examples (specification example 1) of the embodiment of the present invention will be described. Regarding the cooling flow path and the heating flow path, the cross-sectional dimensions of the flow path are 250 μm long × 250 μm wide, and the number of stacked layers is 20 ( When one cooling channel or heating channel is formed on one sheet), channel length is 22 mm, distance between channels is 150 μm, inlet / outlet hole diameter is 1/4 inch (cooling channel), 1/4 inch (heating flow) Road).

  Furthermore, when another specification example (specification example 2) is given, for the cooling channel and the heating channel, the channel cross-sectional dimensions are 500 μm in length × 250 μm in width, the number of stacked layers is 13 or 14 (one cooling channel) Alternatively, when one of the heating channels is formed), the channel length is 22 mm, the distance between channels is 150 μm, the inlet / outlet hole diameter is 1/4 inch (cooling channel), and 1/4 inch (heating channel).

  In the heat exchanger 1 of the above-described embodiment, the metal plate 6 as an element has cooling or heating channels formed on the upper and lower surfaces, respectively, but only on one of the upper and lower surfaces of the metal plate. A plurality of metal plates in which a direction or a horizontal flow path is formed may be laminated and diffusion-bonded so that the vertical flow path and the horizontal flow path are alternately communicated with each other.

  The specific configuration of the heat exchanger according to the present invention has been described above. The points are summarized as follows. As the basic theory of heat transfer, heating and cooling (heat transfer) can be performed more uniformly as the flow path is made smaller. Even if the flow path contributing to the heat transfer of the heat exchanger is short, if a large number of fine flow paths are provided, a sufficient heat transmission rate as a heat exchanger can be obtained. Moreover, in order to exchange heat in large quantities, it is necessary to flow a large flow rate fluid, and it is necessary to flow the fluid at a high flow rate in the flow path.

  According to the present invention, by applying such heat transfer theory to an actual heat exchanger, a laminated structure having a large number of micro-scale fine channels is formed, and the heat exchanger itself has a high pressure resistance in order to apply a high flow rate. This is the basic concept of the heat exchanger.

However, although the heat exchange in one flow path is efficiently performed by using a fine flow path, the absolute value of the amount of heat transferred is small. Further, although there is a problem that it cannot be used at a high pressure due to leakage from the flow path joint portion, in the present invention, by forming the flow path as an integral structure, a high pressure of 80 atmospheres or more, which is the supercritical pressure of CO _2. Has been developed as a heat exchanger and developed as a micro flow channel that can withstand heat.

Therefore, the heat exchanger of the present invention is
(1) A number of fine flow paths have a laminated structure,
(2) High flow rate
With this structure, the amount of heat transferred is increased.

Furthermore, in order to realize such a structure,
(3) By joining a plurality of metal plates having a large number of fine channels formed on the surface by diffusion bonding to form an integrated laminated structure, a large number of laminated fine channels (fine channels) Layer) are laminated and integrated,
(4) High pressure resistant structure capable of high flow rate,
Is realized.

The application is a heat exchanger for a supercritical CO ₂ refrigerant or a supercritical chlorofluorocarbon refrigerant, which is incorporated in a heat pump that uses the supercritical CO ₂ refrigerant. Here, the fine flow channels formed as the heating flow channel and the cooling flow channel in the present invention allow fluid to flow at a high speed and allow heat exchange due to condensation or boiling. The heat pump has a structure that has pressure resistance against a carbon dioxide refrigerant that becomes supercritical at 80 atm or higher or a fluorocarbon refrigerant that becomes supercritical at 40 atm or higher in the heating channel or the cooling channel. is there.

  The integrated laminated structure heat exchanger of the present invention is used in a cogeneration system using a micro gas turbine or a fuel cell, and can be used with high efficiency as a heat exchanger for using waste heat.

  Furthermore, the monolithic laminated heat exchanger of the present invention has a vertical and horizontal dimension of 10 to 1000 μm, and enables high performance heat exchange that can be used in a small distributed energy system.

(Test example)
Several tests were conducted to confirm that the heat exchanger according to the present invention is useful as a heat exchanger for supercritical CO ₂ refrigerant, and test examples thereof will be described.

Pressure test:
Using the heat exchanger of the present invention described in the embodiment (specification example 1 above), a supercooling CO ₂ refrigerant is placed in one of the fine cooling and heating channels crossing each other. In order to investigate the influence of pressure resistance on the other flow path by flowing high pressure water, air flow was changed in the other flow path, and the pressure loss at each flow rate was measured.

  Specifically, high pressure water is flowed into one flow path of the heat exchanger of the present invention by changing the pressure to water by a plunger pump from 0.1 MPa, 5 MPa, 10 MPa, and 15 MPa, and for each pressure, the other The flow rate was appropriately changed by a compressor and air was passed through the flow channel, and the pressure loss due to the flow channel resistance generated in the other flow channel was measured for each flow rate.

  FIG. 4 shows the result of the pressure test, in which water is flowed by changing the pressure of water in one flow path, and for each water pressure, the pressure loss generated in the other flow path with respect to the air flow rate flowing in the other flow path is shown. It is a graph to show. As is apparent from FIG. 4, even if the pressure of water flowing through one flow path is changed to 0.1 MPa, 5 MPa, 10 MPa, and 15 MPa, the resulting pressure loss is not substantially different from each other. However, it was obtained that the pressure loss only increased with respect to the air flow rate.

Then, it was confirmed by visual inspection that there was no deformation or leakage of the heat exchanger even when water was flowed by applying a pressure of 15 MPa to one channel. From the result of this pressure test, it was proved that it can be used for a supercritical CO ₂ refrigerant operated in a refrigeration cycle at about 10 MPa at the highest.

Heat transfer rate test:
Using the heat exchanger of the present invention described in the embodiment (specification example 1 above), one of the microchannels crossing each other is cooled by cooling water (inlet temperature condition: 11.5 ± 1). ° C) is allowed to flow at a different flow rate, and heated water (temperature condition: 80 ± 1 ° C) is passed through the other flow path at flow rates of 0.017 kg / s, 0.025 kg / s, and 0.03 kg / s, The amount of heat exchange was measured by measuring the temperature at which the cooling water in one channel was heated.

  FIG. 5 is a graph showing the results of this heat transfer rate test and showing the heat exchange amount of the water with respect to the flow rate of the water in one flow path. According to FIG. 5, the heat and heat exchange amount tends to increase with an increase in the flow rate of the heating water in the other channel, and a sufficient heat exchange amount is provided. In addition, since the heat exchanger actually used is designed to be larger than the heat transfer area of the above specification example 1, it can be used as a heat exchanger.

Comparison test of heat exchange performance with conventional heat exchanger:
In order to compare the heat exchange performance of the heat exchanger of the present invention (specification example 1) described in the examples with conventional products (comparative examples 1 and 2), A comparative test of exchange performance was performed. In this comparative test, the heating capacity in the condenser of the heat exchanger of the present invention and the heat exchangers of Comparative Examples 1 and 2 is 4.5 kW class. (The scale is suitable for household heat pumps and water heaters.)

The specification of the heat exchanger used in this test is shown in FIG. The amount of heat exchange performance (W / m ³ ) per unit volume of the water heat exchanger with respect to the water flow rate (Kg / s) of one channel is measured, and the measurement result is shown in FIG. It shows with. As shown in FIG. 6 (b), the heat exchange performance (W / m ³ ) of the heat exchanger of the present invention is proved to be about 100 times that of the conventional comparative examples 1 and 2. It was done. Therefore, the heat exchanger can be greatly reduced in size.

Startability test:
A test for a time (start-up time) during which the heat exchanger of the present invention described in the example (specification example 1) is in a steady state (operational state of steady heat exchange) was performed. In this test, cooling water was flowed at a rate of 0.017 kg / s in advance, and heating water was flowed at a rate of 0.017 kg / s later, and the cooling water inlet temperature (T _cin ), the cooling water outlet temperature (T _cout ), and the heating water inlet temperature _{(T hin)} and the heating water outlet temperature _{(T hout),} as well as to measure the time until the steady state.

The results of this startability test are shown in FIG. Approximately 8 seconds after the start of measurement, heating water was started to flow. A few seconds later (about 5 seconds later), the cooling water outlet temperature (T _cout ) also increased rapidly and became a substantially flat steady state. From this result, it is shown that the heat exchanger of the present invention has extremely excellent startability. This is considered to be because the heat exchanger of the present invention has a volume of 0.00005 m ³ , a mass of 230 g and a heat capacity of water that is very small and requires a small amount of heat to reach a steady state.

From the above test results, it was demonstrated that the heat exchanger of the present invention does not deform or break at 15 MPa or less and can withstand a pressure of 15 Mpa or more. As a result of comparison with other types of heat exchangers (Comparative Examples 1 and 2), the amount of heat exchange per unit volume (W / m ³ ) is about 100 times that of the heat exchanger of the present invention. Therefore, the use as a heat exchanger for supercritical CO ₂ refrigerant is optimal from the viewpoints of pressure resistance, heat exchange, and compactness, and it can be incorporated into a heat pump using supercritical CO ₂ refrigerant.

  The best mode for carrying out the heat exchanger according to the present invention has been described based on the embodiments. However, the present invention is not particularly limited to such embodiments, and is described in the claims. It goes without saying that there are various embodiments within the scope of technical matters.

Since the heat exchanger according to the present invention is a small, rich pressure-resistant and highly efficient heat exchanger, it is suitable for a heat pump using a supercritical CO ₂ refrigerant. Furthermore, the heat exchanger according to the present invention constitutes a part of a small distributed energy system for a cogeneration system using a micro gas turbine, a fuel cell, etc., and can use waste heat with high efficiency. is there.

It is a figure explaining the Example of the heat exchanger which concerns on this invention. It is a figure explaining the Example of the heat exchanger which concerns on this invention. (A) is the figure which looked at the heat exchanger unit using the heat exchanger which concerns on this invention from the top, (b) is the figure which cut | disconnected diagonally what is shown by (a), (c) is FIG. It is a figure which shows the result of the pressure | voltage resistant test of the heat exchanger which concerns on this invention. It is a figure which shows the result of the heat exchange amount test of the heat exchanger which concerns on this invention. The heat exchange performance of the heat exchanger according to the present invention is related to a comparative test with a comparative example, (a) shows the respective specifications, and (b) shows the test results. It is a figure which shows the result of the starting time test of the heat exchanger which concerns on this invention.

Explanation of symbols

1 heat exchanger
2 Cooling channel group
3 Cooling channel
4 Heating channel group
5 Heating channel
6 Metal plate
7 Top surface of metal plate
8 Lower surface of metal plate
6A A type metal plate
6B B type metal plate
9 Interface between metals
10 Heat exchanger housing
11 Heat exchanger unit
12, 13 Entrance / exit for flow path

Claims (8)

An integral laminated structure heat exchanger in which the plurality of metal plates are formed in an integral laminated structure so that the heating channel and the cooling channel formed in each of the plurality of metal plates do not communicate with each other,
Each of the plurality of metal plates has one of a heating channel and a cooling channel formed on each surface, and the other of the heating channel and the cooling channel is formed on the back surface with respect to the surface. And
The cross-sectional dimension of the heating channel and the cooling channel is 10 to 1000 μm in length and width, respectively.   The plurality of metal plates are formed in an integrated laminated structure by diffusion bonding, and the joining surface of the laminated structure has the same strength as the metal plate, and is in a supercritical state in the heating channel and the cooling channel. 2. The integrated laminated structure heat exchanger according to claim 1, having a pressure resistance capable of flowing a high-pressure fluid.   3. The integrated laminated structure heat exchanger according to claim 2, wherein the heating channel and the cooling channel allow fluid to flow at high speed and can exchange heat by condensing or boiling.   The heating channel or the cooling channel is used for a heat pump having a pressure resistance against a supercritical carbon dioxide refrigerant or a supercritical chlorofluorocarbon refrigerant. Integrated laminated heat exchanger.   4. The heating channel or the cooling channel has a microchannel structure used for a heat pump accompanied by heat transfer by evaporation and condensation of a supercritical carbon dioxide refrigerant or a supercritical chlorofluorocarbon refrigerant. Or the integral-type laminated structure heat exchanger of 4.   6. The integrated laminated structure heat exchanger according to any one of claims 1 to 5, which is 1/10 to 1/100 the size of a conventional heat exchanger having the same performance, The integrated laminated structure heat exchanger according to claim 2, 3 or 4, wherein the heat exchanger is used as an exchanger.   It is a one-piece | stacked laminated-structure heat exchanger in any one of Claims 1-6, Comprising: It is used for the cogeneration system using a micro gas turbine or a fuel cell, and is highly efficient as a heat exchanger for waste heat utilization An integrated laminated heat exchanger characterized by being usable in   The integrated laminated structure heat exchanger according to any one of claims 2 to 6, wherein the vertical and horizontal dimensions are 10 to 1000 µm, and high-performance heat exchange that can be used in a small distributed energy system is possible. An integrated laminated structure heat exchanger.

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