A heat exchange unit and a microchannel heat exchanger

Abstract

The present invention discloses a heat exchange unit and a microchannel heat exchanger, relating to the technical field of heat exchangers. The heat exchange unit includes: a square cylinder is horizontally arranged with both ends open, and a channel is formed on the inner wall of the square cylinder for the refrigerant to flow through. A plurality of grooves are respectively formed on both sides of the channel, and the plurality of grooves are spaced apart in a linear pattern along the length direction of the channel. The grooves are inclined, and the cross-section of the groove is an isosceles triangle. The base of the isosceles triangle is flush with the side wall of the channel, and the apex angle of the isosceles triangle is an obtuse angle; a plurality of flow disturbing structures are respectively arranged on the bottom wall of the channel, and the plurality of flow disturbing structures are spaced apart in a linear pattern along the length direction of the channel. The advantages of the present invention are that the peak value of the local high-temperature and high-pressure area is effectively reduced, and at the same time, an effective balance between efficiency and energy consumption is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of heat exchangers, and particularly to a heat exchange unit and a microchannel heat exchanger. Background Art

[0002] Modern society increasingly relies on electronic technology products, and various electronic products have become increasingly important around us. At the same time, the development of modern technology products also trends towards being portable and intelligent. This has led to an increasing problem of heat dissipation due to the continuous increase in the chip power density. Modern electronic devices such as servers, high-performance computers, and smartphones generate a large amount of heat during operation, and the average heat flux density of electronic chips is as high as 400W / cm 2 ~800W / cm 2 , and high temperatures can cause problems such as chips losing their effectiveness and shortening their service life.

[0003] Currently, heat dissipation is usually carried out through heat transfer methods such as heat dissipation fins or heat exchangers. The principle of heat dissipation fins is to accelerate the air circulation for heat exchange, but the heat dissipation degree is limited. The principle of heat exchangers is to cool the inside of electronic devices through the heat exchange of refrigerants, which is suitable for highly integrated electronic products. Considerable progress has been made in the design, performance, and application of existing microchannel heat exchangers. Microchannel heat exchangers provide a huge heat exchange surface area through tiny channels, significantly increasing the heat transfer coefficient. Due to their high heat transfer ability, microchannel heat exchangers can achieve the same cooling or heating effect as traditional heat exchangers in a smaller volume, which is particularly suitable for application scenarios with limited space. Although existing microchannel heat exchangers have advantages such as high efficiency and compactness, the channels of current microchannel heat exchangers adopt a uniform flow channel structure, resulting in the accumulation of a thermal boundary layer in the near-wall region due to the velocity gradient, and insufficient turbulent kinetic energy in the mainstream region, leading to a non-linear growth relationship between the heat transfer efficiency and the pump power loss. At the same time, there is an obvious flow stagnation area in the internal channels of existing microchannel heat exchangers, which will result in obvious local high temperature and high pressure conditions. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a heat exchange unit and a microchannel heat exchanger, which effectively reduce the peak value of the local high temperature and high pressure area, and at the same time achieve an effective balance between efficiency and energy consumption.

[0005] The present invention provides a heat exchange unit, comprising:

[0006] A square tube, horizontally arranged, with both ends of the square tube open. A channel is formed on the inner wall of the square tube, and the channel is used for circulating refrigerant. A plurality of grooves are respectively formed on both sides of the channel, and the plurality of grooves are arranged at intervals in a line along the length direction of the channel. The grooves are inclined, and the cross-section of the groove is an isosceles triangle, with the base of the isosceles triangle flush with the side wall of the channel, and the vertex angle of the isosceles triangle being an obtuse angle.

[0007] A plurality of flow disturbing structures are respectively arranged on the bottom wall of the channel, and the plurality of flow disturbing structures are arranged at intervals in a line along the length direction of the channel.

[0008] Preferably, the flow disturbing structure is a flow disturbing column, the flow disturbing column is inclined, the flow disturbing column is located between the grooves on both sides of the channel, and the distances from the flow disturbing column to the grooves on both sides are equal.

[0009] Preferably, the grooves penetrate through the side wall of the channel, and the inclination directions of the plurality of grooves are the same. The flow disturbing column has the same inclination direction as the grooves, and the inclination angle of the flow disturbing column is the same as the inclination angle of the grooves.

[0010] Preferably, the plurality of grooves on each side wall of the channel are distributed in a staggered manner up and down. The top of the groove located above is flush with the top of the channel, the bottom of the groove located below is flush with the bottom of the channel. The inclination directions of the grooves located above are the same, the inclination directions of the grooves located below are the same. The inclination direction of the plurality of flow disturbing columns is the same as the inclination direction of the grooves located below, and the inclination angle of the flow disturbing column is the same as the inclination angle of the grooves located below. The ratios of the projected heights of the grooves located above and below on the side wall of the channel to the height of the channel are both 1:2.

[0011] Preferably, the cross-section of the flow disturbing column is an isosceles triangle or a rectangle or an ellipse.

[0012] Preferably, the flow disturbing structure is two fins, the two fins are arranged at intervals along the width direction of the channel, and the two fins are inclined.

[0013] Preferably, the ratio of the projected height of the fin on the side wall of the channel to the height of the channel is 1:3 to 1:2.

[0014] Preferably, the angle between the central axis of the groove and the length direction of the channel is 30° to 50°.

[0015] Preferably, the ratio of the height of the isosceles triangle to the wall thickness of the square tube is 2:5 to 1:2.

[0016] The present invention provides a microchannel heat exchanger, which includes multiple groups of the heat exchange units. The multiple groups of heat exchange units are arranged in a linear pattern, and the side walls of the square cylinders in two adjacent groups of heat exchange units are fixed. The multiple groups of heat exchange units form an integral structure.

[0017] Compared with the prior art, the present invention discloses a heat exchange unit and a microchannel heat exchanger, and its beneficial effects are as follows:

[0018] The device of the present invention adopts inclined grooves, which greatly increases the surface heat exchange area inside the channels. The grooves change the flow path of the fluid, increasing the chance of the fluid contacting the groove surface. This not only increases the actual contact surface area but also increases the residence time of the fluid inside the channels, thereby improving the heat exchange efficiency. By guiding the development of secondary flow through the curvature of the flow channel cross-section, the vortices in the corner regions of the channels of traditional heat exchangers are effectively dispersed, effectively reducing the peak values in the local high-temperature and high-pressure regions, causing the fluid to generate more vortices and shear layers inside the channels. These vortices and shear layers contribute to increasing the intensity of the secondary flow inside the channels and reducing the stagnation region inside the grooves. Due to the increase in the intensity of the secondary flow and the reduction of the stagnation region, the heat transfer coefficient and heat transfer performance between the fluid and the channel wall surface are significantly improved. At the same time, spoiler columns are also provided. By setting the spoiler columns, the limitation that the grooves can only affect the region close to the channel wall surface can be overcome, thereby improving the fluid mixing and heat transfer efficiency throughout the channels. The spoiler columns will disrupt the laminar flow state of the fluid, prompting the fluid to generate more turbulence, further increasing the contact chance between the fluid and the channel wall surface, improving the heat transfer efficiency, increasing the disturbance effect on the central region of the fluid, and further promoting the enhanced heat transfer of the heat exchanger. Finally, an effective balance between efficiency and energy consumption is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0020] Figure 1 It is a schematic structural diagram of the heating unit of the present invention.

[0021] Figure 2 It is a side view of the heating unit of the present invention.

[0022] Figure 3 It is a side view of the heating unit of the present invention.

[0023] Figure 4 It is a schematic internal structural diagram of the heating unit of the present invention.

[0024] Figure 5Another internal structure schematic diagram of the heating unit of the present invention.

[0025] Figure 6 Schematic diagram of the structure of the turbulator column of the present invention when the cross-section is an isosceles triangle.

[0026] Figure 7 Schematic diagram of the structure of the turbulator column of the present invention when the cross-section is a rectangle.

[0027] Figure 8 Schematic diagram of the structure of the turbulator column of the present invention when the cross-section is an ellipse.

[0028] Figure 9 Schematic diagram of the structure of the microchannel heat exchanger of the present invention.

[0029] Figure 10 Heat distribution nephogram of the present invention when the turbulator column is in the middle and is divided into two fins.

[0030] Figure 11 Heat distribution nephogram of the present invention when the groove is single-layer, double-layer in the same direction, and double-layer in the opposite direction.

[0031] Figure 12 Heat distribution nephogram of the present invention when the ratio of the projected width of the groove to the width of the first side is 2:5 to 1:2, greater than 1:2, and less than 2:5.

[0032] Figure 13 Heat distribution nephogram of the present invention when the inclination angle of the groove is 30° to 50°, greater than 50°, and less than 30°.

[0033] Figure 14 Heat distribution nephogram of the present invention when the ratio of the fin height to the channel height is 1:3 to 1:2, greater than 1:2, and less than 1:3. Detailed description of specific embodiments

[0034] The following combines the accompanying drawings to describe a specific embodiment of the present invention in detail, but it should be understood that the protection scope of the present invention is not limited by the specific embodiment.

[0035] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the technical solutions of the present invention 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 of the present invention.

[0036] In the description of the present invention, it should be noted that, unless otherwise clearly specified and defined, the term "connection" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection. It may be a mechanical connection or an electrical connection. It may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific situations.

[0037] In addition, in the description of the present invention, "a plurality of" means two or more than two. The terms "first" and "second" are only used for descriptive purposes and cannot be understood as implying or indicating relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features.

[0038] Embodiment 1

[0039] An embodiment of the present invention provides a heat exchange unit such as Figure 1As shown, it includes: a square tube 1 and a spoiler structure. Both ends of the square tube 1 are open. The square tube 1 is placed horizontally when in use. A channel 11 is formed on the inner wall of the square tube 1. The channel 11 is used to circulate refrigerant. The square tube 1 includes a first plate and a second plate 4 in an integrated structure. A through groove is provided on the top of the first plate along its length direction. The through groove is the channel 11. The second plate 4 is arranged on the top of the first plate to block the top of the through groove. The first plate and the second plate 4 form a square tube 1 with a hollow center. The wall thickness of the four sides of the square tube 1 is equal. One end of the channel 11 is a fluid inlet for the refrigerant to enter. The other end of the channel 11 is a fluid outlet for the refrigerant to be discharged after heat exchange. When in use, the bottom of the first plate is close to the heat source. At the same time, the material of the first plate is a material with good thermal conductivity, such as copper or aluminum or other materials. The heat dissipated by the heat source is transferred to the first plate. The refrigerant circulates in the channel 11 all the time, thereby performing heat exchange in the channel 11 all the time, cooling the channel 11 and the first plate. At the same time, the first plate performs heat exchange with the heat source, thereby cooling and dissipating the heat source. The heat source can be a computer, a smart phone, etc. The second plate 4 blocks the channel The top of 11 allows the refrigerant to exchange heat through the channel 11 to avoid dissipation from the top of the channel 11. In actual use, the two ends of the channel 11 are connected with a tube body, and the refrigerant flows in the tube body. It also has a cooling structure for cooling the refrigerant, so that the refrigerant discharged from the channel 11 after heat exchange can be cooled again to ensure that the heat source is continuously cooled and dissipated in a cycle. A plurality of grooves 2 are respectively opened on both sides of the channel 11, and the plurality of grooves 2 are spaced in a straight line along the length direction of the channel 11. The grooves 2 are spaced in a straight line along the height direction of the channel 11. The groove 2 is inclined, and the cross section of the groove 2 is an isosceles triangle. The base of the isosceles triangle is flush with the side wall of the channel 11, and the vertex angle of the isosceles triangle is an obtuse angle, that is, the groove 2 is a V-shaped groove recessed toward the inside of the first plate, and the angle of the V-shape is 130°~150°. By setting the V-shaped groove 2, the inner wall area of the channel 11 is increased, that is, the contact area between the refrigerant and the inner wall of the channel 11 can be increased, thereby enhancing the heat exchange effect. The groove 2 is inclined, which can preliminarily enhance the turbulent effect of the groove 2 on the fluid, thereby further enhancing the heat exchange effect. A plurality of flow-disturbing structures are respectively arranged on the bottom wall of the channel 11, and the plurality of flow-disturbing structures are distributed in a straight line along the length direction of the channel 11. In the present embodiment, the flow-disturbing structure is a flow-disturbing column 3, and the flow-disturbing column 3 is arranged obliquely, and the inclination angle of the flow-disturbing column 3 is consistent with the inclination angle of the groove 2. By arranging the flow-disturbing column 3, the incoming refrigerant is further disturbed, the heating boundary layer is periodically disturbed, and a vortex is generated behind the flow-disturbing column 3, which enhances lateral mixing, increases the contact opportunity between the refrigerant and the channel 11 and the wall surface of the groove 2, and enhances the heat exchange effect. The inclined groove 2 arranged in the present device greatly increases the surface heat exchange area in the channel 11 without changing the number of the grooves 2, and the grooves 2 change the flow path of the fluid, so that the opportunity for the fluid to contact the surface of the grooves 2 is increased.This not only increases the actual contact surface area but also increases the residence time of the fluid in channel 11, thereby improving the heat transfer efficiency. At the same time, by setting the inclined groove 2, more vortices and shear layers are generated in channel 11 for the fluid. These vortices and shear layers contribute to increasing the intensity of the secondary flow in channel 11 and reducing the stagnation zone inside groove 2. Due to the increase in the secondary flow intensity and the reduction of the stagnation zone, the heat transfer coefficient and heat transfer performance between the fluid and the wall surface of channel 11 are significantly improved. In addition, the device is also provided with turbulators 3. By setting the turbulators 3, the limitation that the groove 2 can only affect the area near the wall surface of channel 11 can be overcome, thereby improving the fluid mixing and heat transfer efficiency throughout channel 11. The turbulators 3 will disrupt the laminar state of the fluid, prompting the fluid to generate more turbulence, thereby increasing the contact opportunity between the fluid and the wall surface of channel 11 and improving the heat transfer efficiency. This heat exchange unit adopts the inclined groove 2, guides the development of the secondary flow through the curvature of the flow channel cross-section, effectively disperses the vortices in the corner area of the traditional heat exchanger channel, effectively reduces the peak value of the local high-temperature and high-pressure area, and embeds the turbulators 3 between adjacent grooves 2, increasing the turbulator effect on the central area of the fluid and further promoting the enhanced heat transfer of the heat exchanger. Finally, an effective balance between efficiency and energy consumption is achieved.

[0040] As Figure 5 shown, further, the ratio of the projected height of each groove 2 on the side wall of channel 11 to the height of channel 11 is 1:2, that is, the projected height of groove 2 is half of the height of channel 11. The multiple grooves 2 on each side wall of channel 11 are distributed in a staggered manner up and down, that is, the grooves 2 on the side wall of channel 11 are divided into two layers, upper and lower. The grooves 2 in the two layers are distributed in a staggered manner. The top of the groove 2 located above is flush with the top of channel 11, and the bottom of the groove 2 located below is flush with the bottom of channel 11. The inclined directions of the grooves 2 located above are the same, and the inclined directions of the grooves 2 located below are the same, which are divided into two ways. One is that the inclined directions of the grooves 2 located above are the same as those of the grooves 2 located below, and the other is that the inclined directions of the grooves 2 located above are opposite to those of the grooves 2 located below. The inclined directions of the multiple turbulators 3 are the same as those of the grooves 2 located below. As Figure 5 shown, in this embodiment, dividing the groove 2 into two layers, upper and lower, can strengthen the fluid mixing in the same layer, interrupt and reconstruct the thermal boundary layer, and the fluid fluctuation layer can strengthen the fluid mixing between different layers, which is beneficial to further improving the heat transfer.

[0041] Furthermore, the ratio of the height of the isosceles triangle to the wall thickness of the square tube 1 is 2:5 to 1:2. The isosceles triangle means that the cross-section of the above-mentioned groove 2 is an isosceles triangle. Among them, the top surface of the first plate is divided into two first side surfaces 12 with equal widths by the channel 11. The ratio of the projected width of the groove 2 on the first side surface 12 to the width of the first side surface is 2:5 to 1:2, and the best ratio is 2:5, that is, the best ratio of the depth of the groove 2 to the width of the first side surface is 2:5. At this ratio, the heat exchange effect is the best. When it is less than 2:5, the depth of the groove 2 is relatively shallow, so the effective heat transfer area may be reduced, resulting in a decrease in the heat exchange efficiency. The flow velocity may increase, but the residence time is insufficient, and the fluid cannot fully perform heat exchange. When it is greater than 1:2, the depth of the groove 2 is relatively deep, resulting in an increase in the flow resistance, leading to too large a pressure drop and requiring a larger pumping power, which will increase the energy consumption. As Figure 12 shown, it is the heat distribution nephogram when the ratio of the projected width of the groove 2 on the first side surface 12 to the width of the first side surface 12 is 2:5 to 1:2, greater than 1:2, and less than 2:5. Less than the value range means less than 2:5, that is, when the depth of the groove 2 is relatively shallow. Within the value range means that the ratio of the projected width of the groove 2 to the width of the first side surface 12 is within 2:5 to 1:2. Greater than the value range means greater than 1:2, that is, when the depth of the groove 2 is relatively deep, Re refers to the dimensionless parameter of the fluid flow state, Temperature refers to the temperature in the channel 11, and from Figure 12 it can be seen that the heat exchange effect when the ratio of the projected width of the groove 2 to the width of the first side surface 12 is within 2:5 to 1:2 is better than that when it is greater than 1:2 and less than 2:5.

[0042] Furthermore, the angle between the central axis of the groove 2 and the length direction of the channel 11 is 30° to 50°, that is, the inclination angle of the groove 2 is 30° to 50°. When the inclination angle of the groove 2 is greater than or less than this range, it will cause the turbulence effect of the groove 2 on the fluid to weaken and reduce the heat exchange effect. As Figure 13 shown, it is the heat distribution nephogram when the inclination angle of the groove 2 is 30° to 50°, greater than 50°, and less than 30°. Less than the value range means when the inclination angle of the groove 2 is less than 30°. Within the value range means when the inclination angle of the groove 2 is within 30° to 50°. Greater than the value range means when the inclination angle of the groove 2 is greater than 50°, Re refers to the dimensionless parameter of the fluid flow state, Temperature refers to the temperature in the channel 11, and from Figure 13 it can be seen that the heat exchange effect when the inclination angle of the groove 2 is 30° to 50° is better than that when the inclination angle of the groove 2 is greater than 50° and less than 30°.

[0043] Example 2

[0044] As a further improvement based on Embodiment 1, this embodiment provides another distribution pattern of the grooves 2. As Figure 4 shown, further, the ratio of the projected height of the groove 2 on the side wall of the channel 11 to the height of the channel 11 is 1:1, that is, the groove 2 penetrates through the side wall of the channel 11, the top of the groove 2 is flush with the top of the channel 11, the bottom of the groove 2 is flush with the bottom of the channel 11, and the groove 2 is an isosceles triangle, that is, the two waists of the isosceles triangle penetrate through the channel 11 along the height direction of the channel 11 respectively, and the inclination directions of the multiple grooves 2 are the same, and the inclination directions of the multiple flow disturbing columns 3 are the same as the inclination direction of the groove 2. As Figure 4 shown, in this embodiment, the grooves 2 are distributed in a single layer. Firstly, the processing is simpler, and at the same time, the pressure loss is lower than that of the double layer. As Figure 11 shown, the heat distribution nephograms are for the case when the grooves 2 are in a single layer, when the grooves 2 are in a double layer with the same direction, and when the grooves 2 are in a double layer with opposite directions. When in a single layer, the grooves 2 are distributed as Figure 4 shown, the same-direction double layer means the grooves 2 are distributed as Figure 5 shown, and the opposite-direction double layer means taking Figure 5 as an example, the upper-layer grooves 2 are changed to the obliquely upper-left direction or the lower-layer grooves 2 are changed to the obliquely upper-left direction, so that the inclination directions of the upper-layer grooves 2 and the lower-layer grooves 2 are inconsistent. Re refers to the dimensionless parameter of the fluid flow state, Temperature refers to the temperature in the channel 11. It can be seen from Figure 11 that the heat transfer effect when the grooves 2 are distributed in a double layer is better than that when the grooves 2 are distributed in a single layer, and the heat transfer effect when the grooves 2 are in a double layer with the same direction is better than that when the grooves 2 are in a double layer with opposite directions.

[0045] Among them, the other structures of this embodiment are the same as those of Embodiment 1, which is just an optimization of Embodiment 1.

[0046] Embodiment 3

[0047] As a further improvement based on Embodiment 1, further, the multiple grooves 2 on both sides of the channel 11 are divided into multiple groups, with two in each group. The two grooves 2 are symmetrically arranged on both sides of the channel 11. The multiple flow disturbing columns 3 correspond to the number of groups of the grooves 2 one by one. The flow disturbing columns 3 are located between the grooves 2 on both sides of the channel 11, and the distances from the flow disturbing columns 3 to the grooves 2 on both sides are equal. Such a setting of the flow disturbing columns 3 has the best flow disturbing effect.

[0048] As Figures 6 - 8 shown, further, the cross section of the flow disturbing column 3 is an isosceles triangle or a rectangle or an ellipse. The flow disturbing columns 3 with the above shapes all have good flow disturbing effects.

[0049] Furthermore, the cross-section of the turbulator 3 is an isosceles triangle, and the turbulator effect is optimal when the cross-section of the turbulator 3 is an isosceles triangle.

[0050] Among them, the other structures of this embodiment are the same as those of Embodiment 1, except that it is an optimization made to Embodiment 1.

[0051] Embodiment 4

[0052] As a further improved solution based on Embodiment 1, in order to further enhance the turbulator effect, this embodiment provides another turbulator structure. The turbulator structure is two fins 31. The two fins 31 are arranged at intervals along the width direction of the channel 11, and the two fins 31 are inclined. The two fins 31 are respectively close to the two grooves 2. The turbulator structure in this embodiment is to vertically cut the turbulator 3 in the middle in Embodiment 3 to form two fins 31. When the interval between the two fins 31 is zero, the whole turbulator 3 is formed. When the interval between the two fins 31 is greater than zero, two separate fins 31 are formed. According to Embodiment 3, the turbulator effect is optimal when the cross-section of the turbulator 3 is an isosceles triangle. In this embodiment, the cross-sections of the two fins 31 are right-angled triangles, and the longer right-angled sides of the two fins 31 are arranged opposite to each other. The cross-sections of the two fins 3 can be combined to form an isosceles triangle. As Figure 2 shown, the schematic diagram when the turbulator structure is the turbulator 3, as Figure 3 shown, the schematic diagram when the turbulator structure is two fins 31. After being divided into two fins 31, the turbulator effect can be further enhanced, thereby enhancing the heat exchange effect. As Figure 10 shown, the heat distribution nephogram when the turbulator structure is the turbulator 3 and when the turbulator structure is two fins 31. The overall fin refers to the case when the turbulator structure is the turbulator 3, and the separated fin refers to the case when the turbulator structure is two fins 31. Re refers to the dimensionless parameter of the fluid flow state, Temperature refers to the temperature in the channel 11. It can be seen from Figure 10 that the turbulator structure being two fins 31 has a better heat exchange effect. When the turbulator structure is the turbulator 3 and is arranged between two symmetric grooves 2, the heat transfer or the mixing of hot and cold fluids can be effectively enhanced, thereby more evenly destroying the boundary layer and improving the heat exchange effect. When the turbulator structure is two fins 31, compared with the turbulator 3, the pressure loss will increase, but the heat exchange effect becomes better, and at the same time the heat transfer coefficient increases, and the comprehensive evaluation factor also increases. In actual applications, the form of the turbulator structure setting is selected after comprehensively considering factors such as the size of the whole device, heat source and pump power.

[0053] Further, the ratio of the projected height of the fin 31 on the side wall of the channel 11 to the height of the channel 11 is 1:3 to 1:2, and the optimal ratio is 1:3. At this ratio, the flow disturbance effect is the best. When the ratio is less than this value, the projected height of the fin 31 is relatively small, and the pressure loss inside the channel 11 is too large. When the ratio is greater than this value, the projected height of the fin 31 is relatively large, and the heat transfer effect is weak. As Figure 14 shown, for the fin 31, that is, the heat distribution nephograms when the ratio of the height of the flow disturbance column 3 to the channel height is 1:3 to 1:2, greater than 1:2, and less than 1:3. The value less than the range means that the projected height of the fin 31 is relatively small, the value within the range means that the ratio of the projected height of the fin 31 to the channel height is within 1:3 to 1:2, and the value greater than the range means that the projected height of the fin 31 is relatively large. Re refers to the dimensionless parameter of the fluid flow state, Temperature refers to the temperature inside the channel 11, and from Figure 14 it can be seen that when the ratio of the projected height of the fin 31 to the channel height is within 1:3 to 1:2, the heat transfer effect is better than that when it is greater than 1:2 and less than 1:3. As can be seen from the above, the flow disturbance column 3 is the case where the interval between two fins 31 is zero. Therefore, the ratio of the projected height of the flow disturbance column 3 to the channel height is also 1:3 to 1:2.

[0054] Among them, the other structures of this embodiment are the same as those of Embodiment 3, except that it is an optimization of Embodiment 3.

[0055] Embodiment 5

[0056] The embodiment of the present invention provides a microchannel heat exchanger, as Figure 9 shown, including multiple groups of heat exchange units in the above-mentioned Embodiments 1 to 4. The multiple groups of heat exchange units are arranged in a linear pattern, and the side walls of the square cylinders 1 in two adjacent groups of heat exchange units are fixed, usually the side walls in the length direction are fixed together, and the multiple groups of heat exchange units form an integral structure. In practical applications, an appropriate number of heat exchange units can be installed according to the size of the actual heat source, and the multiple groups of heat exchange units are combined together to form a microchannel heat exchanger.

[0057] Comparing this device with the existing microchannel heat exchanger, it is found that:

[0058] When the refrigerant flow rate is 4 m / s, in terms of pressure loss, the pressure loss of this device is approximately 8000 Pa - 10000 Pa greater than that of the existing microchannel heat exchanger. This indicates that the structure of this device will increase the flow resistance of the fluid. In the study of the heat dissipation surface, the temperature of the heat dissipation surface of this device is approximately 4.5 K - 18 K lower than that of the existing microchannel heat exchanger. K is the unit of Kelvin in the Kelvin temperature scale. This shows that the heat dissipation capacity of the structure of this device is 13.5% - 40% higher than that of the existing microchannel heat exchanger. To comprehensively consider the performance of the microchannel heat exchanger, the comprehensive performance index PEC is proposed. PEC refers to the index considering both pressure loss and heat transfer performance. The results show that PEC of this device is 1.54, and PEC of the existing microchannel heat exchanger is 1 - 1.16. The PEC of this device is 24.6% - 54% higher than that of the existing microchannel heat exchanger. In summary, it is concluded that the structure of this device has good heat transfer performance.

[0059] When comparing this device with and without the turbulator 3 added, it is found that: the pressure loss with the turbulator 3 added is 12000 Pa greater than that without the turbulator 3 added. The heating surface temperature with the turbulator 3 added is 1.9 K lower than that without the turbulator 3 added. The PEC with the turbulator 3 added is 1.63, which is 5.8% higher than that without the turbulator 3 added. In summary, the heat transfer performance of the microchannel heat exchanger with the turbulator 3 added is better.

[0060] When comparing the case where the turbulator structure is the turbulator 3 with the case where the turbulator structure is two fins 31, it is found that: increasing the distance between the two fins 31 has little effect on the pressure drop. When the refrigerant flow rate is 4 m / s, the pressure loss when the turbulator structure is two fins 31 increases by 6%. The heating surface temperature is 1.5 K lower than that when the turbulator structure is the turbulator 3. The PEC when the turbulator structure is two fins 31 is 1.65, which is 2% higher than that when the turbulator structure is the turbulator 3 and 5.8% higher than that without the turbulator 3 added. In summary, when the turbulator structure is two fins 31, that is, when the turbulator 3 is separated into two fins 31, the heat transfer performance of the microchannel heat exchanger is better.

[0061] The advantages of the present invention are as follows. The device adopts inclined grooves, which greatly increases the surface heat transfer area in the channel. The grooves change the flow path of the fluid, increasing the chance of contact between the fluid and the groove surface. This not only increases the actual contact surface area but also increases the residence time of the fluid in the channel, thereby improving the heat transfer efficiency. By guiding the development of secondary flow through the curvature of the flow channel cross-section, the vortices in the corner area of the traditional heat exchanger channel are effectively dispersed, and the peak value of the local high-temperature and high-pressure area is effectively reduced, causing more vortices and shear layers to be generated in the channel. These vortices and shear layers contribute to increasing the intensity of the secondary flow in the channel and reducing the stagnation area inside the groove. Due to the increase in the intensity of the secondary flow and the reduction of the stagnation area, the heat transfer coefficient and heat transfer performance between the fluid and the channel wall surface are significantly improved. At the same time, spoiler columns are provided. By setting the spoiler columns, the limitation that the grooves can only affect the area near the channel wall surface can be overcome, thereby improving the fluid mixing and heat transfer efficiency in the entire channel. The spoiler columns will disrupt the laminar flow state of the fluid, prompting the fluid to generate more turbulence, thereby increasing the contact chance between the fluid and the channel wall surface, improving the heat transfer efficiency, increasing the disturbance effect on the central area of the fluid, and further promoting the enhanced heat transfer of the heat exchanger. Finally, an effective balance between efficiency and energy consumption is achieved.

[0062] The above are only several specific embodiments of the present invention disclosed. However, the embodiments of the present invention are not limited thereto, and any changes that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A heat exchange unit, characterized in that, Comprising: A square cylinder (1), horizontally arranged, with both ends of the square cylinder (1) open. A channel (11) is formed on the inner wall of the square cylinder (1), and the channel (11) is used for circulating a refrigerant. A plurality of grooves (2) are respectively formed on both sides of the channel (11). The plurality of grooves (2) are arranged at intervals in a line along the length direction of the channel (11). The grooves (2) are inclined. The cross-section of the groove (2) is an isosceles triangle. The base of the isosceles triangle is flush with the side wall of the channel (11), and the apex angle of the isosceles triangle is an obtuse angle. The plurality of grooves (2) on each side wall of the channel (11) are arranged in a staggered manner up and down. The top of the groove (2) located above is flush with the top of the channel (11), and the bottom of the groove (2) located below is flush with the bottom of the channel (11). The inclination directions of the grooves (2) located above are the same, and the inclination directions of the grooves (2) located below are the same. The projection heights of the grooves (2) located above and the grooves (2) located below on the side wall of the channel (11) and the height of the channel (11) have a ratio of 1:

2. A plurality of flow disturbance structures, respectively arranged on the bottom wall of the channel (11). The plurality of flow disturbance structures are arranged at intervals in a line along the length direction of the channel (11). The flow disturbance structure is a flow disturbance column (3). The flow disturbance column (3) is inclined. The inclination directions of the plurality of flow disturbance columns (3) are the same as the inclination direction of the groove (2) located below, and the inclination angle of the flow disturbance column (3) is the same as the inclination angle of the groove (2) located below. The flow disturbance column (3) is located between the grooves (2) on both sides of the channel (11), and the distances from the flow disturbance column (3) to the grooves (2) on both sides are equal.

2. The heat exchange unit according to claim 1, wherein The groove (2) penetrates the side wall of the channel (11), and the inclination directions of the plurality of grooves (2) are the same. The flow disturbance column (3) has the same inclination direction as the groove (2), and the inclination angle of the flow disturbance column (3) is the same as the inclination angle of the groove (2).

3. The heat exchange unit according to claim 1, characterized in that, The cross-section of the flow disturbance column (3) is an isosceles triangle or a rectangle or an ellipse.

4. The heat exchange unit according to claim 1, characterized in that, The flow disturbance structure is two fins (31). The two fins (31) are arranged at intervals along the width direction of the channel (11), and the two fins (31) are inclined.

5. The heat exchange unit according to claim 4, characterized in that The projection height of the fin (31) on the side wall of the channel (11) and the height of the channel (11) have a ratio of 1:(2 - 3).

6. The heat exchange unit according to claim 1, characterized in that The included angle between the central axis of the groove (2) and the length direction of the channel (11) is 30° - 50°.

7. The heat exchange unit according to claim 1, characterized in that, The ratio of the height of the isosceles triangle to the wall thickness of the square cylinder (1) is 1:(2 - 2.5).

8. A microchannel heat exchanger, characterized in that, Comprising multiple groups of heat exchange units as described in claim 1. The multiple groups of heat exchange units are arranged in a line, and the side walls of the square cylinders (1) in adjacent two groups of heat exchange units are fixed. The multiple groups of heat exchange units form an integral structure.

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