A high-efficiency single-row microchannel heat exchanger

Abstract

This invention relates to a high-efficiency single-row microchannel heat exchanger, comprising an upper collector, a lower collector, microchannel flat tubes, and supporting components. The upper collector is located above the lower collector, and the upper and lower collectors are connected by the microchannel flat tubes. The upper collector has inlet and outlet ports for the heat exchanger on its vertical end faces, with a refrigerant inlet pipe section on one end face and a refrigerant outlet pipe section on the opposite end face. The microchannel flat tubes are arranged in parallel to each other, and their axial direction is perpendicular to the horizontally arranged upper and lower collectors. This high-efficiency single-row microchannel heat exchanger effectively improves drainage performance, ensuring both drainage and defrosting capabilities. The flow channel aperture size of the microchannel flat tubes is further reduced compared to the current mainstream microchannel flow channel size, resulting in a thinner boundary layer, stronger convective heat transfer, more significant heat transfer effect, and better air heat transfer performance. Due to the simple air channel structure, the pressure drop on the air side and the manufacturing difficulty are reduced.

Description

Technical Field

[0001] This invention belongs to the field of heat exchange equipment and enhanced heat transfer technology, specifically relating to a high-efficiency single-row microchannel heat exchanger. Background Technology

[0002] Heat exchangers are devices that facilitate heat exchange between refrigerant and indoor / outdoor air. Improving their heat exchange efficiency can reduce equipment size, increase system compactness, and lower the weight and manufacturing cost of air conditioners. Optimizing the heat exchanger structure to reduce airflow resistance, thereby reducing fan power, is also an effective way to reduce air conditioning energy consumption and noise during operation. Microchannel heat exchangers are compact, highly efficient, and easy to manufacture and assemble, making them widely used in power, food, chemical, air conditioning, and refrigeration engineering fields. Structural optimization aimed at enhancing the performance of microchannel heat exchangers is a hot research topic.

[0003] Existing microchannel heat exchangers typically have fins attached to adjacent microchannel flat tubes in a folded manner. This structural feature makes drainage difficult, and poor drainage can easily lead to operational problems such as frost or dust accumulation, resulting in a decrease in the heat exchange efficiency of the microchannel heat exchanger as it operates. Summary of the Invention

[0004] In order to solve the above-mentioned problems in the prior art, the purpose of this invention is to provide a high-efficiency single-row microchannel heat exchanger with smooth drainage, which can avoid a series of problems caused by poor drainage at the microchannel flat tube and ensure heat exchange effect.

[0005] The technical solution adopted in this invention is as follows:

[0006] A high-efficiency single-row microchannel heat exchanger includes an upper collector, a lower collector arranged parallel below the upper collector, and several groups of microchannel flat tubes arranged between the upper collector and the lower collector. The several groups of microchannel flat tubes are arranged in a row, and the upper end of each group of microchannel flat tubes is connected to the upper collector and the lower end is connected to the lower collector.

[0007] Both the upper and lower collectors are equipped with flow divider baffles. The flow divider baffles are located at the junction between two adjacent groups of microchannel flat tubes. The flow divider baffles in the upper collector and the flow divider baffles in the lower collector enable the several groups of microchannel flat tubes to be connected in sequence to form a serpentine path.

[0008] The upper collector has a refrigerant inlet and a refrigerant outlet at both ends; or the upper collector has a refrigerant inlet and the lower collector has a refrigerant outlet; or the upper collector has a refrigerant outlet and the lower collector has a refrigerant inlet; or the lower collector has a refrigerant inlet and a refrigerant outlet at both ends; the refrigerant inlet and refrigerant outlet are respectively connected to both ends of the serpentine passage.

[0009] Each group of microchannel flat tubes contains multiple parallel microchannel flat tubes with smooth sidewall surfaces.

[0010] Within each group of microchannel flat tubes, the spacing between adjacent microchannel flat tubes is 1.9-2.0 mm; the spacing between two adjacent groups of microchannel flat tubes is 3.8-6.0 mm.

[0011] Preferably, each microchannel flat tube has multiple parallel flow channels, the upper end of which is connected to the upper collector and the lower end of which is connected to the lower collector;

[0012] The flow channels at both ends of the microchannel flat tube in the width direction are D-shaped tubes, with one side of the curved surface of the D-shaped tube facing the outside of the end of the microchannel flat tube in the width direction. The remaining flow channels in the microchannel flat tube are rectangular tubes.

[0013] Preferably, the width of the flow channel cross-section is 0.20-0.35 mm, the length is 0.6-0.7 mm, and the spacing between adjacent flow channels is 0.79-0.94 mm; wherein, the width direction of the flow channel cross-section is the thickness direction of the microchannel flat tube, and the length direction of the flow channel cross-section is the width direction of the microchannel flat tube.

[0014] Preferably, the microchannel flat tube has a width of 21-23 mm and a thickness of 0.65-0.75 mm; both ends of the microchannel flat tube are rounded along the width direction.

[0015] Preferably, the length of the microchannel flat tube is 220-230 mm.

[0016] Preferably, the upper axis of the microchannel flat tube along the height direction is perpendicular to the axis of the upper collector and the axis of the lower collector.

[0017] Preferably, the microchannel flat tube group is configured as four groups, and the ratio of the number of microchannel flat tubes in the four groups is (22-24):(26-28):(25-27):(22-24).

[0018] Preferably, one end of the upper collector is provided with a refrigerant inlet and the other end is provided with a refrigerant outlet;

[0019] The four groups of microchannel flat tubes are sequentially designated as the first group, the second group, the third group, and the fourth group of microchannel flat tubes along the direction from the refrigerant inlet to the refrigerant outlet on the upper collector. Diverter baffles are installed at the junctions of the first and second groups of microchannel flat tubes, and at the junctions of the third and fourth groups of microchannel flat tubes, in the upper collector. A diverter baffle is also installed at the junction of the second and third groups of microchannel flat tubes in the lower collector.

[0020] Preferably, the refrigerant inlet is connected to an inlet pipe section, and the refrigerant outlet is connected to an outlet pipe section.

[0021] Preferably, a support plate is connected between the upper collector and the lower collector, with one end of the support plate fixedly connected to the upper collector and the other end fixedly connected to the lower collector.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] In this invention, a high-efficiency single-row microchannel heat exchanger is constructed where the upper end of a microchannel flat tube group is connected to an upper collector and the lower end to a lower collector. Each microchannel flat tube group contains multiple parallel microchannel flat tubes with smooth sidewall surfaces. The outer surface of the microchannel flat tubes is smooth and finless. The vertical arrangement of the microchannel flat tubes helps reduce water droplet adhesion to the outer surface of the tubes. Under the combined action of wind and gravity, drainage performance is effectively improved, ensuring drainage and defrosting performance. Furthermore, the simple air channel structure reduces the pressure drop on the air side and the difficulty of manufacturing. Simultaneously, to compensate for the reduced heat dissipation capacity due to the lack of fins, the spacing between adjacent microchannel flat tubes in this invention is 1.9-2.0 mm. This increases the heat exchange area, intensifies heat exchange between the hot and cold working fluids, and improves heat exchange efficiency. It also reduces the overall size of the heat exchanger model, improving its compactness. In this invention, several groups of microchannel flat tubes are arranged in a row. The pressure resistance of the external cooling air flowing through the microchannel flat tube group is relatively small, which helps to reduce overall energy consumption. At the same time, the single-row arrangement reduces the overall processing difficulty of the heat exchanger and lowers the requirements for installation applicability. In summary, the high-efficiency single-row microchannel heat exchanger provided by this invention has smooth drainage, which can avoid a series of problems caused by poor drainage at the microchannel flat tubes, while also ensuring heat exchange efficiency.

[0024] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0025] Figure 1 This is a front view of the high-efficiency single-row microchannel heat exchanger of the present invention;

[0026] Figure 2 for Figure 1 The right view;

[0027] Figure 3 for Figure 1 Top view;

[0028] Figure 4 This is a cross-sectional view of the current collector of the present invention;

[0029] Figure 5 This is a cross-sectional view of the current collector of the present invention;

[0030] Figure 6 This is a schematic diagram of the refrigerant flow path of a high-efficiency single-row microchannel heat exchanger according to an embodiment of the present invention;

[0031] Figure 7(a) is a right view of the upper collector of the high-efficiency single-row microchannel heat exchanger of the present invention;

[0032] Figure 7(b) is a top view of the upper collector of the high-efficiency single-row microchannel heat exchanger of the present invention;

[0033] Figure 8(a) is a right view of the lower collector of the high-efficiency single-row microchannel heat exchanger of the present invention;

[0034] Figure 8(b) is a top view of the lower collector of the high-efficiency single-row microchannel heat exchanger of the present invention;

[0035] Figure 9 This is a horizontal cross-sectional view of the microchannel flat tube of the high-efficiency single-row microchannel heat exchanger of the present invention;

[0036] Figure 10 This is an isometric view of the support plate of the high-efficiency single-row microchannel heat exchanger of the present invention;

[0037] Figure 11 This is a top-view streamline distribution diagram of the numerical simulation of the high-efficiency single-row microchannel heat exchanger of the present invention;

[0038] Figure 12 This is a top-view temperature contour map showing the numerical simulation of a high-efficiency single-row microchannel heat exchanger according to an embodiment of the present invention.

[0039] Figure 13 This is a performance comparison diagram between the high-efficiency single-row microchannel heat exchanger of the present invention and existing heat exchangers;

[0040] In the figure: 1-Upper collector; 101-Upper collector inlet diversion baffle; 102-Upper collector outlet diversion baffle; 2-Inlet pipe section; 3-Outlet pipe section; 4-Outlet side support plate; 5-Inlet side support plate; 6-Microchannel flat tube; 6-1-Flow channel; 7-Lower collector; 701-Lower collector diversion baffle. Detailed Implementation

[0041] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the following detailed description of a high-efficiency single-row microchannel heat exchanger based on the present invention is provided in conjunction with the accompanying drawings and specific embodiments.

[0042] The foregoing and other technical contents, features, and effects of the present invention will be clearly presented in the following detailed description of specific embodiments in conjunction with the accompanying drawings. Through the description of the specific embodiments, a more in-depth and concrete understanding can be gained of the technical means and effects adopted by the present invention to achieve its intended purpose. However, the accompanying drawings are for reference and illustration only and are not intended to limit the technical solutions of the present invention.

[0043] See Figures 1-6 The high-efficiency single-row microchannel heat exchanger of this invention includes an upper collector 1, and a lower collector 7 is arranged parallel to the upper collector 1 below it, that is, the axes of the upper collector 1 and the lower collector 7 are parallel. Several groups of microchannel flat tubes are arranged between the upper collector 1 and the lower collector 7. These groups of microchannel flat tubes are arranged in a row, with the upper end of each group connected to the upper collector 1 and the lower end connected to the lower collector 7. Both the upper collector 1 and the lower collector 7 are provided with flow-diverting baffles, which are located at the junction between adjacent groups of microchannel flat tubes. The flow-diverting baffles in the upper collector 1 and the lower collector 7 connect the groups of microchannel flat tubes sequentially into a serpentine path. The refrigerant inlet and refrigerant outlet of this invention have several forms, which can be selected according to actual needs. Specific forms include: refrigerant inlets and refrigerant outlets are provided at both ends of the upper collector 1, such as... Figure 1 The situation shown, and refer to Figure 6 , Figure 6 The direction indicated by the middle arrow is the flow direction of the refrigerant in the serpentine path; or the upper collector 1 has a refrigerant inlet and the lower collector 7 has a refrigerant outlet; or the upper collector 1 has a refrigerant outlet and the lower collector 7 has a refrigerant inlet; or the lower collector 7 has a refrigerant inlet and a refrigerant outlet at both ends; the refrigerant inlet and refrigerant outlet are respectively connected to both ends of the serpentine path; each group of microchannel flat tubes contains multiple parallel microchannel flat tubes 6 with smooth sidewall surfaces. In this invention, no heat dissipation fins are provided between the microchannel flat tubes 6, and the sidewall surfaces of the microchannel flat tubes 6 are smooth, thus allowing water on the surface of the microchannel flat tubes 6 to be drained away in a timely manner. To prevent frost or dust from adhering to the surface of the microchannel flat tubes 6; in each group of microchannel flat tubes, the spacing between adjacent microchannel flat tubes 6 is 1.9-2.0mm. The small spacing arrangement of the microchannel flat tubes 6 increases the heat exchange area, intensifies the heat exchange of hot and cold working fluids, improves heat exchange efficiency, and compensates for the lack of heat dissipation capacity due to the absence of heat dissipation fins; on the other hand, it reduces the overall model size of the heat exchanger and improves the compactness of the heat exchanger; the spacing between two adjacent groups of microchannel flat tubes is 3.8-6.0mm, which is also small, and its function is similar to that of the small spacing between adjacent microchannel flat tubes 6, which can further reduce the overall model size of the heat exchanger.

[0044] See Figure 9In this invention, each microchannel flat tube 6 has multiple parallel flow channels. The upper end of each flow channel is connected to the upper collector 1, and the lower end is connected to the lower collector 7. The flow channels located at both ends of the microchannel flat tube 6 in the width direction are D-shaped tubes, with one side of the curved surface of the D-shaped tube facing outward from the end of the microchannel flat tube 6 in the width direction. Figure 9 Taking the orientation shown as an example, the leftmost D-shaped tube curved surface faces the left end of the width direction of the microchannel flat tube 6, and the rightmost D-shaped tube curved surface faces the right end of the width direction of the microchannel flat tube 6. This structural design ensures the uniformity of heat dissipation at both ends of the microchannel flat tube 6. The remaining flow channels in the microchannel flat tube 6 are rectangular tubes.

[0045] In a preferred embodiment of the present invention, the width of the cross-section of the microchannel flat tube 6 is 0.20-0.35 mm, the length is 0.6-0.7 mm, and the spacing between adjacent channels is 0.79-0.94 mm; the width of the microchannel flat tube 6 is 21-23 mm, and the thickness is 0.65-0.75 mm; wherein, the width direction of the cross-section of the channel is the same as the thickness direction of the microchannel flat tube 6 (i.e., the width direction is the same as the thickness direction). Figure 9 The vertical direction shown is the same as the width direction of the microchannel flat tube 6. Figure 9 (As shown in the left-right direction). In the high-efficiency single-row microchannel heat exchanger of this invention, the flow channel aperture size of the microchannel flat tube 6 is further reduced compared to the current mainstream microchannel flow channel size, and the number of channels on the microchannel flat tube 6 is large. On the one hand, this reduces the amount of refrigerant used; on the other hand, because the heat transfer coefficient of the microchannel increases significantly with the decrease in diameter, compared with existing larger diameter channels, the boundary layer of the microchannel is thinner, the convective heat transfer process is more intense, the heat transfer effect is more obvious, and the heat transfer effect on air is better. Utilizing microchannel heat exchange can effectively reduce the heat exchange area, reduce the overall size of the heat exchanger, ensure the normal operation of the heat exchanger, and improve the heat exchange efficiency.

[0046] See Figure 9 The microchannel flat tube 6 has rounded corners at both ends along its width direction, which helps to ensure uniform heat dissipation at both ends of the microchannel flat tube 6.

[0047] As a preferred embodiment of the above-mentioned solution of the present invention, the length of the microchannel flat tube 6 of the present invention can be 220-230mm. With the optimization of the flow channel design, the height of the microchannel flat tube 6 of the present invention can be reduced, which is beneficial to the miniaturization of the entire heat sink.

[0048] As a preferred embodiment of the above-mentioned solution of the present invention, the upper axis of the microchannel flat tube 6 along the height direction is perpendicular to the axis of the upper collector 1 and the axis of the lower collector 7. In this way, when the radiator of the present invention is used, the upper collector 1 and the lower collector 7 are in a horizontal state, and the microchannel flat tube 6 is in a vertical state, which is conducive to the smooth drainage of water on the surface of the microchannel flat tube 6 and effectively prevents dust accumulation.

[0049] As a preferred embodiment of the above-mentioned solution of the present invention, the microchannel flat tube group is configured as four groups, and the ratio of the number of microchannel flat tubes 6 in the four groups of microchannel flat tube groups is (22-24): (26-28): (25-27): (22-24).

[0050] As a preferred embodiment of the above-mentioned solution of the present invention, the refrigerant inlet is connected to an inlet pipe section 2, and the refrigerant outlet is connected to an outlet pipe section 3. The inlet pipe section 2 and the outlet pipe section 3 facilitate the connection between the high-efficiency single-row microchannel heat exchanger of the present invention and the external refrigerant delivery pipeline.

[0051] As a preferred embodiment of the above-mentioned solution of the present invention, a support plate is connected between the upper collector 1 and the lower collector 7. One end of the support plate is fixedly connected to the upper collector 1 and the other end is fixedly connected to the lower collector 7. The support plate can make the positions of the upper collector 1 and the lower collector 7 relatively fixed, and bear the load for the microchannel flat tube 6. This helps to prevent the microchannel flat tube 6 from deforming and being damaged under long-term stress.

[0052] Example

[0053] Please see Figure 1 , Figure 2 and Figure 3 The high-efficiency single-row microchannel heat exchanger in this embodiment includes an upper collector 1, a lower collector 7, several microchannel flat tubes 6, and other auxiliary accessories.

[0054] The upper collector 1 is located directly above the lower collector 7, and the upper collector 1 and the lower collector 7 are connected by several microchannel flat tubes 6. The microchannel flat tubes 6 are at a 90° angle to the horizontal plane, with their upper and lower ends inserted into the upper collector 1 and the lower collector 7 respectively. The connections between the microchannel flat tubes 6 and the upper collector 1, and between them and the lower collector 7, are sealed. The 90° vertical arrangement of the microchannel flat tubes 6 helps to reduce the adhesion of water droplets to the outside of the wall of the microchannel flat tubes 6 under the action of gravity, thereby improving the occurrence of frost and condensation in humid conditions. It also effectively reduces the residence time of water droplets on the wall of the microchannel flat tubes 6, effectively preventing dust in the environment from being deposited on the surface of the microchannel flat tubes 6 due to water droplet adsorption.

[0055] The upper collector 1 has heat exchanger inlet and outlet on both vertical end faces (i.e. left and right end faces), with refrigerant inlet pipe section 2 on the right end face and refrigerant outlet pipe section 3 on the left end face.

[0056] The upper collector 1 and the lower collector 7 are connected by several parallel microchannel flat tubes 6. These microchannel flat tubes 6 are divided into four groups, numbered from right to left as the first group, the second group, the third group, and the fourth group. All four groups are arranged in a single row, with the longitudinal axis of the microchannel flat tubes 6 perpendicular to the horizontal plane. Within the same group, the spacing between the microchannel flat tubes 6 is 1.9-2.0 mm. The spacing between adjacent groups is 3.8 mm. This single-row arrangement of microchannel flat tubes with a smaller spacing achieves a larger heat exchange area. A spacing of 1.9-2.0 mm results in better turbulence, a higher heat transfer coefficient, and a more significant heat exchange effect, particularly for air heat exchange. In this embodiment, 99 parallel microchannel flat tubes 6 are provided, wherein the ratio of the number of microchannel flat tubes 6 in the first group of microchannel flat tubes, the second group of microchannel flat tubes, the third group of microchannel flat tubes and the fourth group of microchannel flat tubes is 23:27:26:23.

[0057] like Figure 4 and Figure 5 As shown, both the upper collector 1 and the lower collector 7 are equipped with flow-dividing baffles. The upper collector 1 has two flow-dividing baffles, denoted as the upper collector inlet flow-dividing baffle 101 and the upper collector outlet flow-dividing baffle 102, respectively. From right to left, the upper collector inlet flow-dividing baffle 101 and the upper collector outlet flow-dividing baffle 102 are located at 1 / 4 and 3 / 4 of the length of the upper collector, respectively. That is, the upper collector inlet flow-dividing baffle 101 is located in the first group of microchannel flat tubes. At the junction of the first and second microchannel flat tube groups, the upper collector outlet diversion baffle 102 is located at the junction of the third and fourth microchannel flat tube groups; each lower collector 7 is equipped with a diversion baffle, namely the lower collector diversion baffle 701, which is located at 1 / 2 of the length of the lower collector 7, that is, at the junction of the second and third microchannel flat tube groups. By using these diversion baffles, all microchannel flat tubes 6 are divided into four regions in the collector, forming multiple U-shaped refrigerant flow paths (i.e., the serpentine pathways) with upper and lower "U"-shaped flow, allowing the refrigerant to flow through multiple paths and achieve sufficient heat exchange. Specifically, the refrigerant flow direction is as follows: Figure 6 As shown.

[0058] As shown in Figures 7(a), 7(b), 8(a) and 8(b), both the upper collector 1 and the lower collector 7 are rectangular tubes; several microchannel flat tubes 6 are evenly and regularly inserted into the upper collector 1 and the lower collector 7. Considering the processing difficulty and versatility, the insertion depth accounts for 1 / 2 of the height of the cavity inside the upper collector 1 and the lower collector 7.

[0059] like Figure 9 As shown, in this embodiment, the microchannel flat tube 6 is a straight flat tube with a width (left-right direction) of 22mm and a thickness (vertical) of 0.7mm, which is beneficial for improving the air-side heat transfer coefficient. This is mainly achieved by increasing the air-side heat transfer area and blocking the development of the air-side boundary layer. Therefore, the microchannel flat tube 6 is inserted into the collector in a parallel arrangement, as shown... Figure 11 As shown, air mixes along the flow direction, which helps to block the development of the air-side boundary layer and reduce uneven temperature distribution, thereby improving heat exchange efficiency. The microchannel flat tube 6 has a smooth outer surface without fins. The welded flat tube sidewall of the collector slopes downwards towards the airflow direction. Under the combined action of wind and gravity, this effectively improves drainage performance, ensuring drainage and defrosting capabilities. Furthermore, the simple air channel structure reduces pressure drop on the air side and manufacturing difficulty. The projection of the microchannel flat tube 6 on the horizontal plane is parallel to the short side direction, and the center distance of the outermost microchannel flat tube from both short sides of the collector is 10.05 mm. Both ends of the flat tube are rounded.

[0060] like Figure 9 As shown, the microchannel flat tube 6 has multiple parallel flow channels. The total length of these flow channels is 228 mm. The two ends of the flat tube form "D"-shaped flow channels, while the middle part forms an "U"-shaped flow channel. The flow channel orifice height is (…). Figure 9 The vertical direction shown is 0.22mm, and the hole width is (…). Figure 9 The diameter (in the left-right direction shown) is 0.67 mm, and the hole spacing is 0.94 mm. The microchannel orifice size is further reduced compared to the current mainstream microchannel size, and the number of channels on the flat tube is greater. This reduces refrigerant usage and improves operational reliability by reducing channel blockage due to the parallel and partitioned arrangement of the flat tubes. The heat transfer coefficient of the microchannel increases significantly with decreasing diameter. Compared to larger diameter channels, the boundary layer of the microchannel is thinner, resulting in stronger convective heat transfer, more significant heat transfer effect, and better air heat transfer. Utilizing microchannel heat exchange can effectively reduce the overall size of the heat exchanger, ensure normal operation, and improve heat transfer efficiency.

[0061] like Figure 10 As shown, all microchannel flat tubes 6 are equipped with support plates on both sides. The support plates on the left and right sides are designated as the outlet-side support plate 4 and the inlet-side support plate 5, respectively. The support plates are 22mm wide, 1.5mm thick, and 212mm long. The two support plates are located on the outside of the microchannel flat tubes 6 and are arranged parallel to the microchannel flat tubes 6. They support the upper and lower collectors, reduce the pressure on the flat tubes, thereby reducing the risk of deformation and damage to the flat tubes and improving the stability and practicality of the entire heat exchanger system.

[0062] Figure 11 and Figure 12The images show the streamline distribution diagram and temperature contour map of the novel high-efficiency single-row microchannel heat exchanger in this embodiment. Figure 11 It can be seen that after the airflow passes through the microchannel flat tube, a vortex core region is formed at the tail of the flat tube. Figure 12 This manifests as localized high-temperature areas. As airflow passes through each flat tube, it undergoes intense mixing, further enhancing heat exchange between the hot and cold fluids. Figure 12 The cooling air reaches its highest temperature near the wall and gradually decreases as it moves away from the wall. Furthermore, a tail-like temperature transition zone appears at the tail of the microchannel flat tube.

[0063] Figure 13 This paper compares the performance of the novel high-efficiency single-row microchannel heat exchanger of this invention with existing traditional heat exchangers. D7 and D5, as traditional tube-fin heat exchangers, are widely used in various heat exchanger devices. Through numerical simulations of four actual operating conditions, the two important indicators of temperature difference and pressure difference were compared using the same inlet and outlet cross-sections. Figure 13 As shown, for the three types of heat exchangers, the inlet and outlet temperature difference decreases with increasing air inlet velocity, while the inlet and outlet pressure difference increases continuously with increasing air inlet velocity. The high-efficiency single-row microchannel heat exchanger reduces the inlet and outlet pressure difference by 8.9% compared to the D7 heat exchanger under the same operating conditions, and by 7.1% compared to the D5 heat exchanger; the inlet and outlet temperature difference is slightly reduced by 2.8% and 0.1% respectively compared to the D7 and D5 heat exchangers under the same operating conditions. The pressure drop optimization effect of the high-efficiency single-row microchannel heat exchanger gradually improves with increasing inlet air velocity under four simulated operating conditions. Specifically, at an inlet air velocity of 0.8 m / s, the pressure drop between the inlet and outlet of the D7 heat exchanger is reduced by 0.1% and increased by 5.1% compared to the D5 heat exchanger; at an inlet air velocity of 1.3 m / s, the pressure drop between the inlet and outlet of the D7 heat exchanger is reduced by 7.3% and decreased by 5.2% compared to the D5 heat exchanger; at an inlet air velocity of 1.8 m / s, the pressure drop between the inlet and outlet of the D7 heat exchanger is reduced by 12.1% and decreased by 11.8% compared to the D5 heat exchanger; and at an inlet air velocity of 2.3 m / s, the pressure drop between the inlet and outlet of the D7 heat exchanger is reduced by 16.2% and decreased by 16.3% compared to the D5 heat exchanger. The inlet and outlet temperature difference of the high-efficiency single-row microchannel heat exchanger showed a smaller variation compared to the D7 and D5 heat exchangers under four operating conditions. The inlet and outlet temperature difference of the high-efficiency single-row microchannel heat exchanger was more than 2.2% higher than that of the D7 heat exchanger. At the same time, the inlet and outlet temperature difference of the high-efficiency single-row microchannel heat exchanger was also higher than that of the D5 heat exchanger under low inlet wind speed conditions, but the increase was less than that of the D7 heat exchanger.

[0064] The high-efficiency single-row microchannel heat exchanger of this invention effectively improves drainage performance, ensuring both drainage and defrosting capabilities. The flow channel aperture size of the microchannel flat tube is further reduced compared to current mainstream microchannel flow channel sizes, resulting in a thinner boundary layer, stronger convective heat transfer, more significant heat transfer effect, and better air heat transfer performance. Due to the simple air channel structure, the pressure drop on the air side and the manufacturing difficulty are reduced. The above-mentioned solution of this invention also reduces the difficulty of welding the outer side of the flat tube, improves the air-side heat transfer efficiency of the heat transfer tube, improves drainage performance, makes the overall air-side heat transfer more uniform, and reduces the air-side pressure drop. The technical problem to be solved by this invention is achieved through the following technical solutions.

[0065] It should be noted that, in this document, terms such as “comprising,” “including,” or any other variations are intended to cover non-exclusive inclusion, such that an article or device comprising a list of elements includes not only those elements but also other elements not expressly listed. Without further limitations, an element defined by the phrase “comprising…” does not exclude the presence of other identical elements in the article or device comprising said element. Terms such as “connected” or “linked” are not limited to physical or mechanical connections but can include electrical connections, whether direct or indirect. The orientations or positional relationships indicated by terms such as “up,” “down,” “left,” and “right” are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the invention.

[0066] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A high-efficiency single-row microchannel heat exchanger, characterized in that, It includes an upper collector (1), and a lower collector (7) is provided parallel below the upper collector (1). Several sets of microchannel flat tube groups are provided between the upper collector (1) and the lower collector (7). The several sets of microchannel flat tube groups are arranged in a row. The upper end of each set of microchannel flat tube groups is connected to the upper collector (1) and the lower end is connected to the lower collector (7). Both the upper collector (1) and the lower collector (7) are equipped with a flow divider baffle. The flow divider baffle is located at the junction between two adjacent microchannel flat tube groups. The flow divider baffle in the upper collector (1) and the flow divider baffle in the lower collector (7) make the several groups of microchannel flat tube groups connected in sequence to form a serpentine path. The upper collector (1) is provided with a refrigerant inlet and a refrigerant outlet at both ends; or the upper collector (1) is provided with a refrigerant inlet and the lower collector (7) is provided with a refrigerant outlet; or the upper collector (1) is provided with a refrigerant outlet and the lower collector (7) is provided with a refrigerant inlet; or the lower collector (7) is provided with a refrigerant inlet and a refrigerant outlet at both ends; the refrigerant inlet and the refrigerant outlet are respectively connected to the two ends of the serpentine passage; Each group of microchannel flat tubes contains multiple parallel microchannel flat tubes with smooth sidewall surfaces (6). In each group of microchannel flat tubes, the spacing between adjacent microchannel flat tubes (6) is 1.9-2.0 mm; the spacing between two adjacent groups of microchannel flat tubes is 3.8-6.0 mm. Each microchannel flat tube (6) is provided with multiple parallel flow channels, the upper end of which is connected to the upper collector (1) and the lower end of which is connected to the lower collector (7); The flow channels located at both ends of the microchannel flat tube (6) in the width direction are D-shaped tubes, with one side of the curved surface of the D-shaped tube facing the outside of the end of the microchannel flat tube (6) in the width direction. The remaining flow channels in the microchannel flat tube (6) are rectangular tubes. The width of the flow channel cross section is 0.20-0.35mm, the length is 0.60-0.70mm, and the spacing between adjacent flow channels is 0.79-0.94mm; wherein, the width direction of the flow channel cross section is the thickness direction of the microchannel flat tube (6), and the length direction of the flow channel cross section is the width direction of the microchannel flat tube (6); The microchannel flat tube (6) has a width of 21-23 mm and a thickness of 0.65-0.75 mm; both ends of the microchannel flat tube (6) along the width direction are rounded. The upper axis of the microchannel flat tube (6) along the height direction is perpendicular to the axis of the upper collector (1) and the axis of the lower collector (7); The microchannel flat tube group is set into four groups, and the ratio of the number of microchannel flat tubes (6) in the four groups is (22-24): (26-28): (25-27): (22-24).

2. The high-efficiency single-row microchannel heat exchanger according to claim 1, characterized in that, The length of the microchannel flat tube (6) is 220-230 mm.

3. The high-efficiency single-row microchannel heat exchanger according to claim 1, characterized in that, One end of the upper collector (1) is provided with a refrigerant inlet and the other end is provided with a refrigerant outlet; The four groups of microchannel flat tubes are sequentially named as the first group of microchannel flat tubes, the second group of microchannel flat tubes, the third group of microchannel flat tubes, and the fourth group of microchannel flat tubes along the direction from the refrigerant inlet to the refrigerant outlet on the upper collector (1). A flow divider baffle is provided at the junction of the first group of microchannel flat tubes and the second group of microchannel flat tubes, and at the junction of the third group of microchannel flat tubes and the fourth group of microchannel flat tubes in the upper collector (1). A flow divider baffle is provided at the junction of the second group of microchannel flat tubes and the third group of microchannel flat tubes in the lower collector (7).

4. The high-efficiency single-row microchannel heat exchanger according to claim 1, characterized in that, The refrigerant inlet is connected to an inlet pipe section (2), and the refrigerant outlet is connected to an outlet pipe section (3).

5. A high-efficiency single-row microchannel heat exchanger according to claim 1, characterized in that, A support plate is connected between the upper collector (1) and the lower collector (7). One end of the support plate is fixedly connected to the upper collector (1), and the other end is fixedly connected to the lower collector (7).

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