Microchannel heat exchanger and heat pump system having the same

Abstract

The present invention specifically discloses a microchannel heat exchanger and a heat pump system having the same, comprising a liquid pipe and at least one bent flat tube. The sidewall of the liquid pipe is provided with a liquid pipe gas outlet and a liquid pipe liquid inlet, the liquid pipe liquid inlet being located below the liquid pipe gas outlet. One end of each bent flat tube is connected to a first flat tube connection port on the sidewall of the liquid pipe, and the bent flat tube extends into the interior of the liquid pipe. The microchannel heat exchanger of the present invention can separate the gas-phase refrigerant and the liquid-phase refrigerant as much as possible and deliver them more evenly to the flat tubes, avoiding "dry steaming" in the heat exchanger and thus improving the heat exchange performance of the microchannel heat exchanger.

Description

Technical Field

[0001] The present invention relates to the technical field of heat exchangers, and in particular to a microchannel heat exchanger and a heat pump system having the same. Background Art

[0002] Microchannel heat exchangers (MCUs), also known as microchannel heat exchangers, have channels with an equivalent diameter of 10-1000 μm. These heat exchangers have dozens of tiny flow channels within their flat tubes, which are connected to circular headers at both ends. Baffles within the headers divide the heat exchanger flow into several separate flow paths.

[0003] When the microchannel heat exchanger is used as an evaporator, the inlet refrigerant is generally in a gas-liquid two-phase state. However, the manifold of the traditional microchannel heat exchanger has no diversion measures. After entering the manifold, the gas-liquid two-phase refrigerant has obvious stratification phenomenon, resulting in uneven distribution of refrigerant entering the flat tube and poor heat exchange performance of the heat exchanger. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the existing technology and provide a microchannel heat exchanger. The microchannel heat exchanger can separate the gas phase refrigerant and the liquid phase refrigerant as much as possible and can deliver them more evenly to the flat tubes, thus avoiding the "dry steam" problem in the heat exchanger.

[0005] The above-mentioned problem to be solved by the present invention is achieved through the following technical solutions:

[0006] A microchannel heat exchanger includes a liquid pipe and at least one bent flat tube, wherein the side wall of the liquid pipe is provided with a liquid pipe air outlet and a liquid pipe liquid inlet, wherein the liquid pipe liquid inlet is located below the liquid pipe air outlet, one end of each bent flat tube is connected to the first flat tube connection port on the side wall of the liquid pipe, and the bent flat tube extends into the interior of the liquid pipe.

[0007] Preferably, the bent flat tube includes a flat tube transverse portion and a flat tube longitudinal portion, one port of the flat tube longitudinal portion is vertically connected to one port of the flat tube transverse portion as a whole, and the flat tube transverse portion and the flat tube longitudinal portion form an L-shaped bent flat tube, and the flat tube longitudinal portion is located inside the liquid pipe.

[0008] Preferably, the other end of the longitudinal portion of the flat tube is close to the liquid inlet of the liquid tube and the height of the liquid inlet of the liquid tube is higher than that of the other end of the longitudinal portion of the flat tube.

[0009] Preferably, the other ends of all the longitudinal portions of the flat tubes are located on the same water surface.

[0010] Preferably, at least one spacer groove is provided at a side end of the liquid pipe, and a spacer is fixed on the inner wall of the spacer groove. The spacer can divide the interior of the liquid pipe into at least two cavities.

[0011] Preferably, it further comprises an air pipe, wherein a second flat tube connection port is provided at a side end of the air pipe, and the second flat tube connection port is communicated with one end of the bent flat tube.

[0012] Preferably, the other side end of the trachea is provided with a first tracheal air guide port and a second tracheal air guide port, the second tracheal air guide port is located below the first tracheal air guide port and the first tracheal air guide port and the second tracheal air guide port are both connected to the circulation pipe group.

[0013] Preferably, the liquid pipe gas outlet is connected to the circulation pipe group through a first connecting pipe, and a one-way valve is provided on the first connecting pipe.

[0014] Preferably, a heat pump system comprises the microchannel heat exchanger described in any one of the above.

[0015] Preferably, it also includes a circulation pipe group, a diverter, a throttling device, a heat exchanger, a four-way valve and a compressor, the first connecting port of the diverter is connected to the liquid inlet of the liquid pipe, the second connecting port of the diverter is connected to the first connecting port of the throttling device, the second connecting port of the throttling device is connected to the first connecting port of the heat exchanger, the second connecting port of the heat exchanger is connected to the four-way valve, the four-way valve is connected to the circulation pipe group, and the compressor is connected to the four-way valve.

[0016] Beneficial effect: After adopting the structure described in the present invention, since the liquid inlet of the liquid pipe is located below the air outlet of the liquid pipe, after the gas-liquid two-phase refrigerant enters the interior of the collecting pipe, it is stratified in the cavity of the collecting pipe. Under the action of gravity, the liquid refrigerant enters the heat exchanger at the lower part of the collecting pipe cavity through the bent flat tube port extending into the interior of the liquid pipe. The gaseous refrigerant at the upper end does not pass through the heat exchanger, but enters the heat exchange system from the liquid pipe air outlet at the upper part of the liquid pipe, thereby achieving a more uniform refrigerant diversion state in the bent flat tube, and at the same time avoiding the "dry steaming" situation in the heat exchanger, which is beneficial to improving the heat exchange performance of the microchannel heat exchanger. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of a microchannel heat exchanger described in the present invention.

[0018] Figure 2 It is a structural schematic diagram of a liquid pipe of a microchannel heat exchanger described in the present invention.

[0019] Figure 3 It is a structural schematic diagram of a microchannel heat exchanger described in the present invention.

[0020] Figure 4 This is a schematic diagram of a system cycle when the heat pump system described in the present invention serves as an evaporator.

[0021] Figure 5This is a schematic diagram of a system cycle when the heat pump system described in the present invention serves as a condenser.

[0022] Figure 1-5 :1- bent flat tube; 2- liquid tube; 3- horizontal part of flat tube; 4- longitudinal part of flat tube; 5- gas outlet of liquid tube; 6- liquid inlet of liquid tube; 7- spacer; 8- spacer groove; 9- first flat tube connection port; 10- air tube; 11- first air tube air guide port; 12- second flat tube connection port; 13- second air tube air guide port; 14- one-way valve; 15- circulation tube group; 16- diverter; 17- throttling device; 18- heat exchanger; 19- four-way valve; 20- compressor. DETAILED DESCRIPTION

[0023] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but the embodiments do not limit the present invention in any form.

[0024] Example 1:

[0025] like Figure 1-2 A microchannel heat exchanger shown includes a liquid pipe 2 and at least one bent flat tube 1. The side wall of the liquid pipe 2 is provided with a liquid pipe air outlet 5 and a liquid pipe liquid inlet 6. The liquid pipe liquid inlet 6 is located below the liquid pipe air outlet 5. One end of the bent flat tube 1 is connected to the first flat tube connection port 9 on the side wall of the liquid pipe 2 and the bent flat tube 1 extends to the interior of the liquid pipe 2. The shape of the liquid pipe 2 can be round, square, D-shaped, etc.

[0026] In this embodiment, since the liquid inlet of the liquid pipe is located below the liquid pipe outlet, the gas-liquid two-phase refrigerant enters the manifold and is stratified in the manifold cavity. Under the action of gravity, the liquid refrigerant enters the heat exchanger at the lower part of the manifold cavity through the bent flat tube port extending into the liquid pipe. The gaseous refrigerant at the upper end does not pass through the heat exchanger, but enters the heat exchange system from the liquid pipe outlet at the upper part of the liquid pipe, thereby achieving a more uniform refrigerant diversion state in the bent flat tube. At the same time, it can also avoid the "dry steaming" phenomenon in the heat exchanger, which is beneficial to improving the heat exchange performance of the microchannel heat exchanger.

[0027] The other structures of this embodiment are the same as those of embodiment 1, except that: Figure 1-2 As shown, the bent flat tube 1 includes a flat tube transverse portion 3 and a flat tube longitudinal portion 4. One end of the flat tube longitudinal portion 4 is vertically connected to one end of the flat tube transverse portion 3 as a whole, and the flat tube transverse portion 3 and the flat tube longitudinal portion 4 form an L-shaped bent flat tube. The flat tube longitudinal portion 4 is located inside the liquid pipe 2. The L-shaped bent flat tube structure can make the liquid refrigerant more evenly transported to the heat exchanger, thereby avoiding "dry steam" in the heat exchanger.

[0028] The other structures of this embodiment are the same as those of the above embodiment, except that: Figure 1-2 As shown, the other end of the flat tube longitudinal portion 4 is close to the liquid pipe inlet 6 and the height of the liquid pipe inlet 6 is higher than the position of the other end of the flat tube longitudinal portion 4. Through the flat tube longitudinal portion in a suitable and reasonable position, the liquid-phase refrigerant can be transported to the heat exchanger more evenly as much as possible, thereby improving the utilization rate of the liquid-phase refrigerant.

[0029] The other structures of this embodiment are the same as those of the above embodiment, except that: Figure 1-2 As shown, the other ends of all the flat tube longitudinal portions 4 are on the same water surface. By maintaining the horizontal ends of the flat tube longitudinal portions, the liquid-phase refrigerant gas can be further transported more evenly.

[0030] The other structures of this embodiment are the same as those of the above embodiment, except that: Figure 1-2 As shown, the side end of the liquid pipe 2 is provided with at least one partition groove 8, and a partition 7 is fixed on the inner wall of the partition groove 8. The partition 7 can divide the interior of the liquid pipe 2 into at least two cavities. Through the separation effect of the partition, the refrigerant gas can be quickly stratified as much as possible, thereby improving the transportation speed and efficiency of the refrigerant gas, and thus improving the heat exchange efficiency.

[0031] The other structures of this embodiment are the same as those of the above embodiment, except that: Figure 1 As shown, it also includes an air pipe 10 , and a second flat tube connecting port 12 is provided at the side end of the air pipe 10 , and the second flat tube connecting port 12 is connected to one end of the bent flat tube 1 .

[0032] Specifically, the other side end of the trachea 10 is provided with a first tracheal air guide port 11 and a second tracheal air guide port 13, the second tracheal air guide port 13 is located below the first tracheal air guide port 11 and the first tracheal air guide port 11 and the second tracheal air guide port 13 are both connected to the circulation pipe group 15.

[0033] The other structures of this embodiment are the same as those of the above embodiment, except that: Figure 3 As shown, the liquid pipe outlet 5 is connected to the circulation pipe group 15 through a first connecting pipe, and a one-way valve 14 is provided on the first connecting pipe. The one-way valve can make the gas-phase refrigerant medium more stably transported to the heat pump system, thereby improving the utilization rate of the heat exchange medium.

[0034] like Figure 4-5 A heat pump system is shown, comprising the technical features of any of the above embodiments.

[0035] Specifically, it also includes a circulation pipe group 15, a diverter 16, a throttling device 17, a heat exchanger 18, a four-way valve 19 and a compressor 20. The first connecting port of the diverter 16 is connected to the liquid inlet 6 of the liquid pipe, the second connecting port of the diverter 16 is connected to the first connecting port of the throttling device 17, the second connecting port of the throttling device 17 is connected to the first connecting port of the heat exchanger 18, the second connecting port of the heat exchanger 18 is connected to the four-way valve 19, the four-way valve 19 is connected to the circulation pipe group 15, and the compressor 20 is connected to the four-way valve 19.

[0036] Working principle: When the microchannel heat exchanger is used as an evaporator, the ac and bd of the four-way valve are connected. The refrigerant discharged from the compressor enters the heat exchanger through the four-way valve for condensation and heat release, then enters the throttling device (valve) for throttling, and then is split into N paths by the splitter and enters the microchannel heat exchanger. The liquid refrigerant evaporates and absorbs heat through the flat tubes and flows out from the air pipe outlet. The gaseous refrigerant flows out from the upper part of the cavity, passes through the one-way valve for gas-liquid bypass, and then merges with the evaporated refrigerant coming out from the left side. Finally, it passes through the four-way valve and returns to the compressor to complete the cycle.

[0037] When the microchannel heat exchanger is used as a condenser, a and b of the four-way valve are connected, and c and d are connected. The refrigerant discharged from the compressor passes through the four-way valve. Due to the existence of the one-way valve, the gaseous refrigerant all enters from the gas pipe, condenses and releases heat through the bent flat tube, and then flows out through N liquid pipes. After being merged by the diverter, it enters the throttle valve (device) for throttling, then enters the heat exchanger for evaporation and heat absorption, and then returns to the compressor through the four-way valve to complete the cycle.

[0038] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings and the terms "first" and "second", which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the present invention.

[0039] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0040] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, from all perspectives, the embodiments should be regarded as illustrative and non-restrictive. The scope of the present invention is defined by the appended claims, not the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be included within the present invention. Any reference signs in the claims should not be construed as limiting the claim to which they relate.

[0041] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A microchannel heat exchanger, characterized in that: It includes a liquid pipe and at least one bent flat tube, the side wall of the liquid pipe is provided with a liquid pipe air outlet and a liquid pipe liquid inlet, the liquid pipe liquid inlet is located below the liquid pipe air outlet, one end of the bent flat tube is connected to the first flat tube connecting port on the side wall of the liquid pipe and the bent flat tube extends to the interior of the liquid pipe; the bent flat tube includes a flat tube transverse portion and a flat tube longitudinal portion, one port of the flat tube longitudinal portion is vertically connected to a port of the flat tube transverse portion as a whole, and the flat tube transverse portion and the flat tube longitudinal portion form an L-shaped bent flat tube, the flat tube longitudinal portion is located inside the liquid pipe, the other port of the flat tube longitudinal portion is close to the liquid pipe inlet, and the height of the liquid pipe inlet is higher than the position of the other port of the flat tube longitudinal portion.

2. The microchannel heat exchanger according to claim 1, characterized in that: The other ends of the longitudinal portions of all the flat tubes are located on the same water surface.

3. The microchannel heat exchanger according to claim 1, characterized in that: At least one spacer groove is provided at a side end of the liquid pipe, a spacer is fixed on the inner wall of the spacer groove, and the spacer divides the interior of the liquid pipe into at least two cavities.

4. The microchannel heat exchanger according to claim 1, characterized in that: It also includes an air pipe, and a second flat tube connecting port is provided at the side end of the air pipe, and the second flat tube connecting port is connected to one end of the bent flat tube.

5. The microchannel heat exchanger according to claim 4, characterized in that: The other side end of the trachea is provided with a first tracheal air guide port and a second tracheal air guide port, the second tracheal air guide port is located below the first tracheal air guide port, and the first tracheal air guide port and the second tracheal air guide port are both connected to the circulation pipe group.

6. The microchannel heat exchanger according to claim 5, characterized in that: The liquid pipe gas outlet is connected to the circulation pipe group through a first connecting pipe, and a one-way valve is provided on the first connecting pipe.

7. A heat pump system, characterized in that: The microchannel heat exchanger comprises the microchannel heat exchanger according to any one of claims 1 to 6.

8. A heat pump system according to claim 7, characterized in that: It also includes a circulation pipe group, a diverter, a throttling device, a heat exchanger, a four-way valve and a compressor. The first connecting port of the diverter is connected to the liquid inlet of the liquid pipe, the second connecting port of the diverter is connected to the first connecting port of the throttling device, the second connecting port of the throttling device is connected to the first connecting port of the heat exchanger, the second connecting port of the heat exchanger is connected to the four-way valve, the four-way valve is connected to the circulation pipe group, and the compressor is connected to the four-way valve.

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