Microchannel Heat Exchanger

Abstract

The present application discloses a microchannel heat exchanger comprising: a flat tube body and a row of channels, wherein the row of channels is arranged in the flat tube body along the width direction, and the row of channels penetrates the flat tube body along the length direction, wherein the cross section of each channel comprises a first width along the width direction and a first height along the thickness direction, and the row of channels at least comprises a first channel, a second channel and a third channel along the width direction; the first widths of the first channel, the second channel and the third channel are reduced at a fixed ratio, thereby facilitating the control of the thickness of the microchannel flat tube and improving the heat exchange efficiency of the microchannel heat exchanger.

Description

Technical Field

[0001] The present application relates to the field of heat exchange, and in particular, to a microchannel heat exchanger. Background Art

[0002] Microchannel heat exchanger is a heat exchange device commonly used in automobile, household or commercial air conditioning systems. It can be used as an evaporator of the air conditioning system or as a condenser. Microchannel heat exchanger is a heat exchanger composed of flat tubes, fins, manifolds, etc. When the wind generated by the external fan acts on the microchannel fins and flat tubes, the refrigerant in the flat tube flow channel of the microchannel heat exchanger exchanges heat with the air. Each flat tube of the microchannel heat exchanger has a flow channel composed of multiple side-by-side small holes, and the refrigerant evaporates or condenses in the side-by-side flow channels of the flat tubes; when used as a condenser, the refrigerant is cooled in the side-by-side flow channels of the flat tubes; when used as an evaporator, the refrigerant is evaporated in the side-by-side flow channels of the flat tubes. The flat tubes used in the related technology have multiple side-by-side flow channels with the same cross-sectional area. When wind flows through the heat exchanger, due to the heat transfer between the wind and the refrigerant, the refrigerant temperature in each side-by-side flow channel is different along the wind flow direction. Therefore, along the refrigerant flow direction, the refrigerant evaporates or condenses at different positions in the side-by-side flow channels, resulting in a mismatch between the refrigerant flow distribution in the flow channel and the heat exchange temperature difference, thereby reducing the heat exchange efficiency of the heat exchanger.

[0003] like Figure 1 As shown, another related technology uses the cross-section of the microchannel flat tube to gradually decrease from the windward side to the leeward side. The temperature difference of the windward side channel is relatively large, and the refrigerant flow rate is relatively large, so more heat exchange can be performed at a high heat exchange rate. The flow rate of the leeward side channel is relatively small, and its heat exchange rate is also low, so the heat exchange is very small. In this related technology, along the wind blowing direction, the width of all flat tube channels remains unchanged, and the height of the flat tube channels gradually decreases. Due to the different heights of the flat tube channels set in this way, the wall thickness of the flat tube channels with a smaller height on the leeward side is larger, resulting in waste of flat tube materials and increased costs; and the channel thermal resistance at the thicker wall increases. Summary of the invention

[0004] According to one aspect of the present application, a microchannel heat exchanger is provided, comprising: a first header, a second header, a microchannel flat tube and a fin, wherein the microchannel flat tube is connected between the first header and the second header, the fin is sandwiched between two adjacent microchannel flat tubes, a row of channels of the microchannel flat tube communicates with the inner cavity of the first header and the inner cavity of the second header, the microchannel flat tube comprises a flat tube body and a row of channels, and the row of channels is arranged in the flat tube body along the width direction;

[0005] The flat tube body comprises a first plane, a second plane, a first side surface and a second side surface, wherein the first plane and the second plane are arranged at two opposite sides of the flat tube body in the thickness direction, the first side surface and the second side surface are arranged at two opposite sides of the flat tube body in the width direction, the first side surface connects the first plane and the second plane, and the second side surface connects the first plane and the second plane;

[0006] Each of the channels includes a first width along the width direction and a first height along the thickness direction, and the row of channels includes at least a first channel, a second channel and a third channel arranged along the width direction, the first heights of the first channel, the second channel and the third channel are equal, and the first widths of the first channel, the second channel and the third channel decrease at a fixed ratio.

[0007] The first heights of the first channel, the second channel and the third channel of the microchannel heat exchanger of the present application are equal, and the first widths of the first channel, the second channel and the third channel are reduced at a fixed ratio. In this way, the material of the microchannel flat tube is effectively utilized, material waste is reduced, and the heat exchange efficiency of the third channel is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a schematic diagram of a microchannel flat tube of the related art;

[0009] Figure 2 is a three-dimensional schematic diagram of a microchannel heat exchanger according to an embodiment of the present application;

[0010] Figure 3 like Figure 2 A schematic cross-sectional view of a microchannel flat tube;

[0011] Figure 4 for Figure 3 Schematic diagram of the relationship between the channel width and channel number of the microchannel flat tube channel shown. DETAILED DESCRIPTION

[0012] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0013] The terms used in this application are only for the purpose of describing specific embodiments, and are not intended to limit this application. In the description of this application, it should be understood that the orientation or position relationship indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to this application. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" can explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0014] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0015] In the present application, unless otherwise expressly specified and limited, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or the first and second features not being in direct contact but being in contact through another feature between them. Moreover, the first feature being "above", "above" and "above" the second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature includes the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature. The exemplary embodiments of the present application are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the features in the following embodiments and implementations may complement or combine with each other.

[0016] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms "a", "said" and "the" used in this application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0017] The exemplary embodiments of the present application are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the features of the following embodiments and implementations can be combined with each other.

[0018] like Figures 2 to 4 The microchannel heat exchanger 100 according to the present application is shown, which includes a first header 11, a second header 12, a plurality of microchannel flat tubes 2 and a plurality of fins 3. The plurality of microchannel flat tubes 2 are arranged in parallel with each other and connected side by side between the first header 11 and the second header 12, and each fin 3 is sandwiched between two adjacent microchannel flat tubes 2.

[0019] The microchannel flat tube 2 includes a flat tube body 21 and a row of channels 22 that penetrate the flat tube body 21. The length of the flat tube body 21 is greater than its width, and the width is greater than its thickness. The flat tube body 21 includes a first plane 211, a second plane 212, a first side surface 213 and a second side surface 214. The first plane 211 and the second plane 212 are arranged on opposite sides of the flat tube body 21 in the thickness direction H, and the first side surface 213 and the second side surface 214 are arranged on opposite sides of the flat tube body 21 in the width direction W. The first side surface 213 connects the first plane 211 and the second plane 212, and the second side surface 214 connects the first plane 211 and the second plane 212. In this embodiment, the first side surface 213 and the second side surface 212 are arc-shaped. In other optional implementations, the first side surface 213 and the second side surface 212 can also be planes or other shapes, as long as they can connect the first plane 211 and the second plane 212, and the present application is not limited to this shape.

[0020] A row of channels 22 connects the inner cavity of the first header 11 and the inner cavity of the second header 12, and the row of channels 22 is arranged in the flat tube body 21 along the width direction W, and the row of channels 22 penetrates the flat tube body 21 along the length direction L. Each channel 22 includes a first width 22W along the width direction W and a first height 22H along the thickness direction H. The row of channels 22 includes a first channel 221, a second channel 222, and a third channel 223 arranged along the width direction, wherein the first height 22H of the first channel 221, the second channel 222, and the third channel 223 are equal in size, and the first width 22W of the first channel 221, the second channel 222, and the third channel 223 decreases at a fixed ratio. In other words, the first width 22W of the first channel 221, the second channel 222, and the third channel 223 changes linearly, and the cross-sectional areas of the first channel 221, the second channel 222, and the third channel 223 change linearly.

[0021] A row of channels 22 includes a group of first channels 221, a group of second channels 222, and a group of third channels 223. A group of first channels 221 includes five of the first channels 221, a group of second channels 222 includes five of the second channels 222, and a group of third channels 223 includes five of the third channels 223. Optionally, a group of first channels 221, a group of second channels 222, and a group of third channels 223 may also be other numbers, and the present application is not limited thereto. The number of a group of first channels 221 is equal to the number of the group of second channels 222, and the number of a group of first channels 221 is equal to the number of the group of third channels 223.

[0022] The cross-sectional areas of the first channel 221, the second channel 222, and the third channel 223 are all in the shape of a rounded rectangle. The first channel 221 includes four first chamfers 231, the second channel 222 includes four second chamfers 232, and the third channel 223 includes four third chamfers 233. The radius of the first chamfer 231, the radius of the second chamfer 232, and the radius of the third chamfer 233 are equal or reduced at a fixed ratio. In this embodiment, the radius of the first chamfer 231 and the radius of the second chamfer 232 are equal.

[0023] The spacing J1 between two adjacent first channels 221 in a group of first channels 221 is equal, the spacing J2 between two adjacent second channels 222 in a group of second channels 222 is equal, and the spacing J3 between two adjacent third channels 233 in a group of third channels 223 is equal. The spacing J4 between adjacent first channels 221 and second channels 222 is greater than or equal to the spacing J5 between adjacent second channels 222 and third channels 223. The spacing J4 between adjacent first channels 221 and second channels 222 is equal to the spacing J1 between two adjacent first channels 221. The spacing J5 between adjacent second channels 222 and third channels 223 is equal to the spacing between two adjacent third channels J3, and the spacing J5 between adjacent second channels 222 and third channels 223 is less than the spacing J2 between two adjacent second channels 222.

[0024] As an optional embodiment of the present invention, a row of channels 22 further includes five fourth channels 224 and six fifth channels 225. The spacing J6 between two adjacent fourth channels 224 in a group of fourth channels 224 is equal, and the spacing J7 between two adjacent fifth channels 225 in a group of fifth channels 225 is equal. The spacing J8 between adjacent third channels 223 and fourth channels 224 is equal to the spacing J9 between adjacent fourth channels 224 and fifth channels 225.

[0025] As an optional embodiment of the present invention, the width of the microchannel flat tube 2 is 25.4 mm, and the thickness of the microchannel flat tube 2 is 1.3 mm. The first height 22H of the first channel 221, the second channel 222, the third channel 233, the fourth channel 224, and the fifth channel 225 is equal, all of which are 0.74 mm. The distance between the first channel 221, the second channel 222, the third channel 233, the fourth channel 224, and the fifth channel 225 and the first plane is 0.28 mm, and the distance between the first channel 221, the second channel 222, the third channel 233, the fourth channel 224, and the fifth channel 225 and the first width 22H are 0.86, 0.76, 0.66, 0.56, and 0.46 mm, respectively. The dimensions of J1, J2, and J4 are all 0.32 mm, and the dimensions of J3, J5, J6, J7, J8, and J9 are all 0.28 mm. The radius of the chamfer of the first channel 221 , the second channel 222 , the third channel 233 , and the fourth channel 224 is 0.2 mm, and the radius of the chamfer of the fifth channel 225 is 0.1 mm.

[0026] As another optional embodiment of the present invention, the first width 22H of the five first channels 221 can also be reduced in sequence, for example, the first width 22W of the five second channels 221 are respectively: 0.90, 0.88, 0.86, 0.84, 0.82 mm. The first width 22W of the five second channels 222 can also be reduced in sequence, for example, the first width 22W of the five second channels 222 are respectively: 0.80, 0.78, 0.76, 0.74, 0.62 mm. The first width 22W of the five third channels 223 can also be reduced in sequence, for example, the first width 22W of the five third channels 223 are respectively: 0.70, 0.68, 0.66, 0.64, 0.62 mm. The first width 22W of the five fourth channels 224 can also be reduced in sequence, for example, the first width 22W of the five fourth channels 224 are respectively: 0.50, 0.58, 0.56, 0.54, 0.52 mm. The first width 22H of the six fifth channels 225 can also be reduced in sequence. For example, the first width 22W of the six fourth channels 224 are respectively 0.40, 0.48, 0.46, 0.44, 0.42, and 0.40 mm. In this way, the first width 22W of a row of channels 22 satisfies the relationship y=-0.02x+0.92, where x represents the sequence number of the channels in a row of channels 22 from left to right, and y represents the size of the first width 22W of the corresponding x-th channel. Relatively speaking, the sizes of the first width 22H of the five first channels 221, the five second channels 222, the five third channels 233, the five fourth channels 224, and the six fifth channels 225 are respectively 0.86, 0.76, 0.66, 0.56, and 0.46 mm, which are easier to process and easier to control tolerances. Of course, since the specific size of the first width 22W in the present application is an optional embodiment, other specific sizes can also be selected, as long as the first width size of a row of channels 22 changes linearly in sequence or in groups. Of course, the above-mentioned slight changes in size due to processing errors are also within the protection scope of the present application.

[0027] The above is only a preferred embodiment of the present application and does not constitute any form of limitation to the present application. Although the present application has been disclosed as a preferred embodiment as above, it is not intended to limit the present application. Any technician familiar with the profession can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present application. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application still falls within the scope of the technical solution of the present application.

Claims

1. A microchannel heat exchanger, characterized in that: include: A first header, a second header, a microchannel flat tube and a fin, wherein the microchannel flat tube is connected between the first header and the second header, the fin is sandwiched between two adjacent microchannel flat tubes, a row of channels of the microchannel flat tube communicates with the inner cavity of the first header and the inner cavity of the second header, the microchannel flat tube comprises a flat tube body and a row of channels, and the row of channels is arranged in the flat tube body along the width direction; The flat tube body comprises a first plane, a second plane, a first side surface and a second side surface, wherein the first plane and the second plane are arranged at two opposite sides of the flat tube body in the thickness direction, the first side surface and the second side surface are arranged at two opposite sides of the flat tube body in the width direction, the first side surface connects the first plane and the second plane, and the second side surface connects the first plane and the second plane; Each of the channels includes a first width along the width direction and a first height along the thickness direction, and the row of channels includes at least a first channel, a second channel and a third channel arranged along the width direction, wherein the first heights of the first channel, the second channel and the third channel are equal, the first widths of the first channel, the second channel and the third channel decrease at a fixed ratio, and the first widths of the first channel, the second channel and the third channel change linearly.

2. The microchannel heat exchanger according to claim 1, characterized in that: The row of channels includes a group of first channels and a group of second channels, the group of first channels includes a plurality of the first channels, the group of second channels includes a plurality of the second channels, and the number of the group of first channels is equal to the number of the group of second channels.

3. The microchannel heat exchanger according to claim 2, characterized in that: The row of channels includes a group of third channels, the group of third channels includes a plurality of the third channels, and the number of the group of first channels is equal to the number of the group of third channels.

4. The microchannel heat exchanger according to claim 1, characterized in that: The cross-sectional areas of the first channel, the second channel and the third channel are all in the shape of a rounded rectangle. The first channel includes four first chamfers, the second channel includes four second chamfers, and the third channel includes four third chamfers.

5. The microchannel heat exchanger according to claim 4, characterized in that: The radius of the first chamfer, the radius of the second chamfer, and the radius of the third chamfer are equal or decrease at a fixed ratio.

6. The microchannel heat exchanger according to claim 1, characterized in that: The distance between the first channel and the second channel is greater than or equal to the distance between the second channel and the third channel.

7. The microchannel heat exchanger according to claim 3, characterized in that: The spacing between two adjacent first channels in the group of first channels is equal, the spacing between two adjacent second channels in the group of second channels is equal, and the spacing between two adjacent third channels in the group of third channels is equal.

8. The microchannel heat exchanger according to claim 7, characterized in that: The distance between adjacent first channels and second channels is equal to the distance between two adjacent first channels.

9. The microchannel heat exchanger according to claim 7, characterized in that: The spacing between adjacent second channels and third channels is equal to the spacing between two adjacent third channels, and the spacing between adjacent second channels and third channels is smaller than the spacing between two adjacent second channels.

10. The microchannel heat exchanger according to claim 1, characterized in that: The first current collecting pipe and the second current collecting pipe are arranged parallel to each other, the extension direction of the microchannel flat tube is perpendicular to the extension direction of the first current collecting pipe, and the extension direction of the microchannel flat tube is perpendicular to the extension direction of the second current collecting pipe.

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