Microchannel heat exchanger

Abstract

To provide a microchannel heat exchanger having a simple structure composed of a component capable of being formed by pressing.SOLUTION: The present invention relates to a microchannel heat exchanger 1 comprising a cylindrical housing 2 and a rectangular parallelepiped heat exchanger 3 whose four corners are integrally coupled to an inner peripheral surface of the housing, where the housing 2 is formed by a frame part 31 of a first plate unit 30 and a frame part 41 of a second plate unit 40, and the heat exchanger 3 is formed by a closure plate part 32 of the first plate unit 30 and a heat exchange channel plate part 42 of the second plate unit 40.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a microchannel heat exchanger that performs heat exchange between two types of fluids.

Background Art

[0002] Patent Document 1 (Japanese Patent Application Laid-Open No. 2005-83676) addresses the problem of increasing the flow path cross-sectional area in a heat exchanger core used in a microchannel heat exchanger to reduce the resistance of the flow path. A first plate with a plurality of flow paths formed on its surface and a flat second plate are overlapped to form a plate portion. The plate portions are stacked in a plurality of stages such that the longitudinal directions of the flow paths are alternately orthogonal, and the side edge portions are removed to form the heat exchanger core.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Disclosure of the Invention

Problems to be Solved by the Invention

[0004] In a heat exchanger, it is generally known that the heat transfer coefficient inside the tube of the heat exchanger is proportional to the reciprocal of the flow path cross-sectional dimension of the tube. When the heat exchanger is made into a microchannel, a high heat transfer coefficient can be obtained. Also, when the fluid in a narrow channel is made into a high-speed flow, the boundary layer becomes thinner, but the temperature gradient inside the tube becomes even larger, so an increase in the heat exchange rate through the tube wall can be expected. Especially in the field of cold and heat equipment, high performance improvements such as a dramatic reduction in size and weight and an improvement in heat transfer performance of the heat exchanger due to microchannelization are expected.

[0005] A microchannel refers to a narrow flow path formed using microfabrication technology and the like, and generally refers to those with a diameter of several millimeters or less where the influence of surface tension appears.

[0006] The advantages of using microchannels include: (1) Miniaturization and weight reduction facilitate the exploration of new applications and the optimal design of the system. (2) By improving the efficiency of the heat exchanger, it is possible to reduce the blower power such as an air-cooling fan. (3) It is possible to increase the pressure resistance of the heat exchanger. (4) Since the heat exchanger can be miniaturized, the refrigerant filling amount can be reduced, and the environmental load can be reduced. And so on.

[0007] The disadvantages include: (1) Since etching or diffusion bonding is generally used for microchannel formation, the cost is high. (2) Also, defects such as leakage due to problems with etching or diffusion bonding increase the defect rate, which is a factor in cost increase. And so on are assumed.

[0008] A general manufacturing method for a laminated type small heat exchanger (microchannel heat exchanger) is to perform half-etching (referred to as half-etching) on the flow path part in a concave shape from one side of a thin plate material (stainless steel plate, aluminum plate, cylinder plate, etc.) by etching. Since the through part is also etched simultaneously from the opposite side to create the through part and the non-through part, two types of plates are required. In addition, the etching process takes a long time, there are many pre-processes such as pattern creation, exposure, resist, and development, expensive equipment is used, and plate costs are involved, so there is a drawback that the cost inevitably increases.

[0009] In Patent Document 1, an example is disclosed in which the flow path portion of the plate is pierced by pressing without using etching. However, as it is, since the structure cannot secure the flow path portion after joining, mechanical processing is unavoidably performed in a subsequent process. By performing mechanical processing, it is possible to secure the flow path, but there is a risk that cutting powder, cutting oil containing dust, etc. may enter the narrow flow path, and there is a drawback that the cost increases due to the addition of the cutting process.

[0010] In addition, since the plate is not integrated with the housing, even if it is pressed, the cost reduction effect is incomplete.

[0011] Therefore, the present invention provides a microchannel heat exchanger comprising components that do not require cutting, have a structure capable of securing a flow path after plate joining, and can be formed by inexpensive pressing, etching, or laser processing.

Means for Solving the Problems

[0012] Therefore, the microchannel heat exchanger according to the present invention includes a cylindrical housing portion, a rectangular parallelepiped heat exchange portion integrally connected at four corners to the inner peripheral surface of the housing, four fluid passages defined between the inner peripheral surface of the housing portion and the heat exchange portion, a lid plate that closes one end of the housing portion and has four fluid inlets and outlets communicating with the respective four fluid passages, and a bottom plate that shields the other end of the housing portion. The heat exchange portion includes a first heat exchange passage that communicates two of the fluid passages arranged opposite to each other, and a second heat exchange passage that communicates the other two fluid passages arranged opposite to each other, and in the microchannel heat exchanger arranged to be alternately orthogonal in the axial direction of the housing portion, the housing portion and the heat exchange portion are composed of an annular frame portion forming the housing portion and a square closing plate portion integrally connected at four corners to the frame portion, and a first plate unit having four fluid passage forming spaces between the frame portion and the closing plate portion, and an annular frame portion forming the housing portion, and a heat exchange flow path plate portion integrally connected at four corners to the frame portion and having a short side substantially equal to one side of the closing plate portion, and a second plate unit having four fluid passage forming spaces between the frame portion and the heat exchange flow path plate portion, and the second plate unit in which a plurality of microchannel openings extending along the longitudinal direction are formed in the heat through-flow path plate, and the first plate unit, the second plate unit, the first plate unit, the second plate unit rotated 90°, and the first plate unit are stacked in this order.

[0013] With the above configuration, according to the present invention, for example, one of the fluids that performs heat exchange flows into one of the fluid passages (the first fluid passage) communicating with one of the fluid inlet and outlet portions (the first fluid inlet) formed in the lid plate, passes through the first heat exchange passage communicating with the first fluid passage, and is discharged from one of the fluid inlet and outlet portions (the first fluid outlet) facing one of the fluid inlet and outlet portions through the other fluid passage (the third fluid passage) located at a position facing the first fluid passage. Thus, the first fluid circulation cycle is constituted.

[0014] On the other hand, the other fluid that undergoes heat exchange flows from a fluid inlet / outlet portion (second fluid inlet) adjacent to one of the fluid inlet / outlet portions into a fluid passage (second fluid passage) that communicates with it, passes through a second heat exchange passage that communicates with this second fluid passage, and is discharged from a fluid passage (second fluid outlet) that faces the fluid inlet / outlet portion adjacent to one of the fluid inlet / outlet portions via the other fluid passage (fourth fluid passage) located opposite the second fluid passage. This completes a second fluid circulation cycle. In this way, heat exchange can be performed between the fluid flowing through the first heat exchange passage and the fluid flowing through the second heat exchange passage that is perpendicular to the first heat exchange passage.

[0015] In addition, by clamping and fixing the second plate unit with the first plate unit, the heat exchange flow passage plate part of the second plate unit is closed at the top and bottom by the closing plate part of the first plate unit, and the top and bottom of the multiple microchannel openings extending along the longitudinal direction of the heat exchange flow passage plate part are closed, so that multiple microchannels extending along the longitudinal direction of the heat exchange flow passage plate are formed, and for example, a first heat exchange flow passage that communicates the first fluid passage and the third fluid passage is formed. In addition, by disposing the second plate unit rotated by 90° with respect to the second plate unit above it under the first plate unit that closes the lower side of the second plate unit, and further closing the lower side of the first plate unit, a second heat exchange flow passage perpendicular to the first heat exchange flow passage can be formed. By repeating this operation, four fluid passages and microchannels that alternately communicate with each of the opposing fluid passages are formed, and the first heat exchange flow passage and the second heat exchange flow passage are formed.

[0016] This allows the microchannel heat exchanger to be constructed with a small number of parts, and also reduces the manufacturing cost because it is necessary to create only the molds for manufacturing the first and second plates. [Effects of the Invention]

[0017] According to the microchannel heat exchanger of the present invention, the structure is changed to be manufacturable by press punching the microchannel openings, and only two types of the first plate and the second plate are used, so that the number of parts can be reduced and the manufacturing cost can also be reduced.

[0018] In addition, since the outer diameter is cylindrical, the pressure resistance performance is improved. Also, regarding the joining of the first plate unit and the second plate unit, since the microchannels are arranged so as to intersect, the strength is improved. Further, since the two fluids (for example, gas and liquid) that perform heat exchange are completely separated, only the outer peripheral portion of the housing needs to be sealed, so that joining with an inexpensive adhesive or caulking can be enabled without using an expensive processing method such as diffusion bonding.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Figure 4

Best Mode for Carrying Out the Invention

[0020] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Embodiment

[0021] As shown in FIG. 1, a microchannel heat exchanger 1 according to an embodiment of the present invention comprises a cylindrical housing portion 2, a rectangular parallelepiped heat exchange portion 3 having four corners 21, 22, 23, and 24 integrally connected to the inner peripheral surface of the housing portion, four fluid passages (a first fluid passage 4, a second fluid passage 5, a third fluid passage 6, and a fourth fluid passage 7) defined between the inner peripheral surface of the housing portion and the heat exchange portion 3, and a first fluid passage 4 that closes one end of the housing portion 2 and communicates with each of the four fluid passages 4, 5, 6, and 7. The heat exchange section 3 is composed of a cover plate 12 having four fluid inlets and outlets (a first fluid inlet 8, a first fluid outlet 9, a second fluid inlet 10, and a second fluid outlet 11) and a bottom plate 13 that covers the other end of the housing section 2. In the heat exchange section 3, a first heat exchange passage 14 that connects the first and third fluid passages 4, 6 arranged opposite to each other, and a second heat exchange passage 15 that connects the second and fourth fluid passages 5, 7 arranged opposite to each other are arranged so as to be alternately perpendicular to the axial direction of the housing section 2.

[0022] With the above configuration, according to the present invention, for example, one fluid performing heat exchange flows from the first fluid inlet 8 formed in the cover plate into the first fluid passage 4 communicating therewith, passes through the first heat exchange passage 14 communicating with this first fluid passage 4, and is discharged from the first fluid outlet 9 opposing the first fluid inlet 8 via the third fluid passage 6 positioned opposite the first fluid passage 4. This constitutes a first fluid circulation cycle.

[0023] On the other hand, the other fluid that performs heat exchange flows from the second fluid inlet 10 into the second fluid passage 5 communicating therewith, passes through the second heat exchange passage 15 communicating with the second fluid passage 5, and is discharged from the second fluid outlet 11 via the fourth fluid passage 7 located opposite to the second fluid passage 5. This forms a second fluid circulation cycle. In this way, heat exchange can be performed between the fluid flowing through the first heat exchange passage 14 and the fluid flowing through the second heat exchange passage 15 perpendicular to the first heat exchange passage 14.

[0024] With the above configuration, since the two fluids flow through the first heat exchange passage 14 and the second heat exchange passage 15 arranged to cross alternately in the heat exchange section 3, heat exchange between the two fluids is achieved.

[0025] In addition, the housing section 2 and the heat exchange section 3 are configured by alternately arranging a first plate unit 30 as shown in FIG. 2(a) and a second plate unit 40 as shown in FIG. 2(b).

[0026] As shown in FIG. 2(a), the first plate unit 30 is composed of an annular frame body section 31 that forms the housing section 2, and a square closed plate section 32 whose four corners 21’, 22’, 23’, 24’ are integrally connected to the frame body section 31. There are four fluid passage forming spaces 4’, 5’, 6’, 7’ between the frame body section 31 and the closed plate section 32. Also, the length of one side of the closed plate section 32 is set to be L-α. This first plate unit 30 is preferably formed by press working.

[0027] As shown in FIG. 2(b), the second plate unit 40 is composed of an annular frame body section 41 that forms the housing section 2, and a rectangular heat exchange flow path plate section 42 whose four corners 21”, 22”, 23”, 24” are integrally connected to the frame body section 41 and whose short side is approximately equal to L-α, which is one side of the closed plate section. There are four fluid passage forming spaces 4”, 5”, 6”, 7” between the frame body section 41 and the heat exchange flow path plate section 42. Incidentally, the longitudinal length of the heat exchange flow path plate section 42 is L.

[0028] In the second plate unit 40, a plurality of microchannel openings 44 extending along the longitudinal direction are formed in the heat exchange channel plate portion 42. The second plate 40 is also preferably formed by pressing, similar to the first plate unit 30, and it is preferable to simultaneously form the microchannel openings 44 during this pressing process. Incidentally, the description will continue with the third plate unit 40' which is obtained by rotating the second plate unit 40 by 90°.

[0029] With the first plate unit 30 and the second plate unit 40 (and the third plate unit 40') having the above configuration, the housing portion 2 and the heat exchange portion 3 are formed. Specifically, as shown in FIG. 3, it is configured by stacking the first plate unit 30, the second plate unit 40, the first plate unit 30, and the third plate unit 40' in order. As a result, the microchannel openings 44 in the heat exchange channel plate portion 42 of the second plate unit 40 are blocked in the vertical direction by the closing plate portion 32 of the first plate unit 30 arranged above and below, so that the first heat exchange channel 14 is formed by a plurality of microchannels defined thereby. Further, the microchannel openings 44 of the third plate 40' located below and arranged after being rotated by 90° are blocked in the vertical direction by the closing plate portion 32 of the first plate unit 30 arranged above and below, so that the second heat exchange channel 15 formed by a plurality of microchannels formed thereby is formed.

[0030] The first fluid passage 4 is formed by a fluid passage forming space 4' of the first plate unit 30 and a fluid passage forming space 4" of the second plate unit 40, the second fluid passage 5 is formed by a fluid passage forming space 5' of the first plate unit 30 and a fluid passage forming space 5" of the second plate unit 40, the third fluid passage 6 is formed by a fluid passage forming space 6' of the first plate unit 30 and a fluid passage forming space 6" of the second plate unit 40, and the fourth fluid passage 7 is formed by a fluid passage forming space 7' of the first plate unit 30 and a fluid passage forming space 7" of the second plate unit 40.

[0031] 4, the housing section 2 is formed by the frame section 31 of the first plate unit 30 and the frame section 41 of the second plate unit 40, and the heat exchange section 3 is formed by the closing plate section 32 of the first plate unit 30 and the heat exchange flow path plate section 42 of the second plate unit 40. The four corners 21, 22, 23, 24 of the heat exchange section 3 are formed by stacking the four corners 21', 22', 23', 24' of the first plate unit 30 and the four corners 21", 22", 23", 24" of the second plate unit 40, and block the first, second, third and fourth fluid passages 5, 6, 7, 8.

[0032] As described above, according to the present invention, the microchannel heat exchanger 1 can be configured with a small number of parts. In addition, the first plate unit 30 and the second plate unit 40 can be manufactured by punching with a press, and since it is necessary to create only a die for the press, the manufacturing cost can be reduced. [Explanation of symbols]

[0033] 1. Microchannel heat exchanger 2 Housing 3 Heat exchange section 4. First fluid passage 5 Second fluid passage 6 Third fluid passage 7 Fourth fluid passage 8 First fluid inlet 9 First fluid outlet 10 Second fluid inlet 11 Second fluid outlet 12 Lid plate 13 Bottom plate 14 First heat exchange passage 15 Second heat exchange passage 30 First Plate Unit 31 Frame body part 32 Closure plate part 40 Second Plate Unit 41 Frame body part 42 Heat exchange flow path plate part 44 microchannel openings

Claims

【Claim 1】 A microchannel heat exchanger comprising: a cylindrical housing portion; a rectangular parallelepiped heat exchange portion integrally connected at four corners to the inner peripheral surface of the housing; four fluid passages defined between the inner peripheral surface of the housing portion and the heat exchange portion; a lid plate that closes one end of the housing portion and has four fluid inlets and outlets communicating with each of the four fluid passages; and a bottom plate that shields the other end of the housing portion. In the microchannel heat exchanger, the heat exchange portion includes a first heat exchange passage that communicates two of the fluid passages arranged opposite to each other and a second heat exchange passage that communicates the other two fluid passages arranged opposite to each other, and the first and second heat exchange passages are arranged alternately orthogonally to the axial direction of the housing portion. The housing portion and the heat exchange portion are composed of an annular frame portion forming the housing portion and a square closing plate portion integrally connected at four corners to the frame portion, and a first plate unit having four fluid passage forming spaces between the frame portion and the closing plate portion. A second plate unit composed of an annular frame portion forming the housing portion and a heat exchange flow path plate portion integrally connected at four corners to the frame portion and having a short side substantially equal to one side of the closing plate portion, and having four fluid passage forming spaces between the frame portion and the heat exchange flow path plate portion. The heat exchange flow path plate has a plurality of microchannel openings extending along the longitudinal direction. The microchannel heat exchanger is formed by stacking the first plate unit, the second plate unit, the first plate unit, the second plate unit rotated 90°, and the first plate unit in this order.

Images