Micro-channel heat exchanger with special-shaped cross section

Abstract

The application discloses a micro-channel heat exchanger with special-shaped section. The application comprises a shell and a capillary heat exchange pipe component, the capillary heat exchange pipe component is arranged in the shell, and the shell is provided with a liquid inlet and a liquid outlet on two sides. The capillary heat exchange pipe component comprises a plurality of capillary heat exchange pipe assemblies, each capillary heat exchange pipe assembly comprises a plurality of capillary heat exchange pipe pairs arranged in parallel. The capillary heat exchange pipe pair comprises two metal capillary heat exchange pipes with the same shape, the vertical section of the capillary heat exchange pipe is a special-shaped section, the contour line of the special-shaped section is a closed curve composed of two circular arc lines and an elliptical arc line, the hydraulic diameter of the closed curve is less than or equal to 2 mm, and the contour lines of the special-shaped sections of the two capillary heat exchange pipes are centrally symmetric. One end of all the capillary heat exchange pipes is connected with a working medium inflow cavity, and the other end is connected with a working medium outflow cavity. The application can obtain a more efficient heat exchanger system by reducing the hydraulic diameter of the flow channel, can bear higher pressure, and is beneficial to safe, stable and efficient working of refrigerant.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of air conditioning technology, and particularly relates to a micro-channel heat exchanger with special cross section. BACKGROUND

[0002] The conventional heat exchange pipe commonly used at present usually adopts the form of a 9.52mm copper pipe plus an aluminum fin. The large pipe diameter makes the proportion of the number and the outer surface area of the finned heat exchanger pipe small, and the outer surface area occupied by the fin large. Therefore, the optimization of pressure drop and air resistance is carried out from the optimization of the fin structure. The finless micro-pipe heat exchanger is welded by thousands of micro-pipe bundles with a diameter of less than 2mm. A large number of round pipes block the air flow like a forest, resulting in a large pressure loss and flow resistance, thereby reducing the overall efficiency. In view of this, the present application adopts a micro-pipe heat exchanger with a cross section in the shape of an airfoil to reduce the influence of air resistance and reduce the air side pressure drop. SUMMARY

[0003] The present application provides a micro-channel heat exchanger with special cross section according to the problems of insufficient pressure resistance of the conventional heat exchanger and low refrigeration efficiency in the existing air conditioning system, reduces the influence of fluid, and reduces the fluid side pressure drop.

[0004] The present application comprises a shell and a capillary heat exchange pipe component. The opposite sides of the shell are provided with a flow inlet and a flow outlet. The capillary heat exchange pipe component is arranged in the shell.

[0005] The capillary heat exchange pipe component comprises a plurality of capillary heat exchange pipe assemblies. Each capillary heat exchange pipe assembly comprises a plurality of capillary heat exchange pipe pairs arranged in parallel. The plurality of capillary heat exchange pipe pairs of the same capillary heat exchange pipe assembly are vertically projected identically.

[0006] Each capillary heat exchange pipe pair comprises two capillary heat exchange pipes with the same shape. The capillary heat exchange pipe is a metal cylindrical pipe. The vertical cross section of the capillary heat exchange pipe is a special cross section. The profile line of the special cross section is a closed curve composed of two circular arc lines and an elliptical arc line. The hydraulic diameter of the closed curve is less than or equal to 2mm.

[0007] The arc head of the closed curve is a half circumference of a positive ellipse. The starting point A is the highest point of the horizontal ellipse. The terminal point B is the lowest point of the positive ellipse. The straight line AB is the minor axis a of the positive ellipse. The major axis b of the positive ellipse is k*a. The ratio k of the major axis to the minor axis is 1.5-2.5.

[0008] The sharp corner tail of the closed curve is the intersection point C of the two circular arc lines. The two centers of the two circles where the two circular arc lines are located are vertically projected identically. The distance h between the two centers is a+R2-R1. R1 is the radius of the circle where the circular arc line AC is located. R2 is the radius of the circle where the circular arc line BC is located. R2=β*R1. The ratio coefficient β is 1.5-2.5.

[0009] On the same vertical section, the profile lines of the special-shaped sections of the two capillary heat exchange pipes in the pair are two center-symmetrical closed curves, the tip tail point C of the profile line ABC of one capillary heat exchange pipe is the same as the vertical projection point of the tip tail point C' of the profile line A'B'C' of the other capillary heat exchange pipe, the distance l1 between the two tip tail points is λ·a, and the proportion coefficient λ is 0.5-1.0.

[0010] All the capillary heat exchange pipes are connected in parallel, one end of the capillary heat exchange pipe is connected with the working medium inflow cavity, the other end is connected with the working medium outflow cavity, the working medium inlet of the working medium inflow cavity and the working medium outlet of the working medium outflow cavity are separately arranged at the diagonal positions of the capillary heat exchange pipe component.

[0011] Further, the interval l2 between the upper and lower two adjacent capillary heat exchange pipes of one capillary heat exchange pipe assembly is γ·l1, and the proportion coefficient γ is 1.0-1.5.

[0012] Further, on the vertical section of the capillary heat exchange pipe component, the arc head positions of the profile lines of the two adjacent capillary heat exchange pipes on the left and right correspond to each other, and the horizontal projection of the elliptic arc line part in the arc line is the same; the interval l3 between the two adjacent capillary heat exchange pipes on the left and right is δ·l1, and the proportion coefficient δ is 0.5-0.8.

[0013] The micro-pipe heat exchanger without fins used in the application has a hydraulic diameter less than 2mm, and the smaller diameter can bear higher pressure, which is beneficial to the safe, stable and efficient work of the refrigeration system. The application can obtain a more efficient heat exchanger system by reducing the hydraulic diameter of the flow channel, can bear higher pressure, and is beneficial to the safe, stable and efficient work of the refrigerant. The capillary heat exchange pipes are arranged in a forked row, and the pipe diameter along the wind blowing direction can be appropriately changed to reduce the wind resistance as much as possible, thereby reducing the pressure loss and improving the overall efficiency of the refrigeration system.

[0014] The application not only achieves better air conditioner control and energy saving effect, but also does not use dehumidifying solution and solid adsorbent which are toxic, harmful and strongly corrosive to human body, has the advantages of environmental protection, health and very high safety, and has the advantages of compact structure, convenient later maintenance and product upgrading, low cost and reliable operation. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 It is a whole structure schematic view of the application;

[0016] Figure 2 It is a structure diagram of the capillary heat exchange pipe component;

[0017] Figure 3 It is a position schematic view of the capillary heat exchange pipe in the capillary heat exchange pipe component;

[0018] Figure 4 A specific diagram of the capillary heat exchange tube;

[0019] Figure 5 A specific diagram of the flow direction of the fluid in the heat exchanger. DETAILED DESCRIPTION

[0020] The following detailed description of the embodiments of the present application is based on the technical solution of the present application, and gives a detailed implementation and specific operation process, but the protection scope of the present application is not limited to the following embodiments.

[0021] As shown in FIGS. Figure 1 , 2 and 3, a micro-channel heat exchanger with a special cross-section includes a shell 1 and a capillary heat exchange tube component 2. The shell 1 is provided with a fluid inlet 1-1 and a fluid outlet 1-2 on opposite sides, and the capillary heat exchange tube component 2 is arranged in the shell 1. The capillary heat exchange tube component 2 includes a plurality of (1000 or more) capillary heat exchange tubes 2-1, all of which are connected in parallel. One end of the capillary heat exchange tube is connected to a working fluid inlet chamber 2-2, and the other end is connected to a working fluid outlet chamber 2-3. The working fluid inlet of the working fluid inlet chamber 2-2 and the working fluid outlet of the working fluid outlet chamber 2-3 are arranged at opposite corners of the capillary heat exchange tube component 2. The solid arrows in the figure represent the inlet and outlet directions of the fluid, and the dashed arrows represent the inlet and outlet directions of the working fluid.

[0022] The capillary heat exchange tube component 2 includes a plurality of capillary heat exchange tube assemblies, each of which includes a plurality of capillary heat exchange tube pairs arranged in parallel in the vertical direction. Each capillary heat exchange tube pair includes two capillary heat exchange tubes 2-1 with the same shape. The capillary heat exchange tube is a metal cylindrical tube, and its vertical cross-section is a special cross-section. The profile of the special cross-section is a closed curve composed of two circular arcs and an elliptical arc. The hydraulic diameter of the closed curve is less than or equal to 2 mm.

[0023] As shown in FIGS. Figure 4 , the arc head of the closed curve is half the circumference of a positive ellipse. The starting point A is the highest point of the positive ellipse, the ending point B is the lowest point of the positive ellipse, the straight line AB is the minor axis a of the positive ellipse, the major axis b of the positive ellipse is k⋅a, and the ratio of the major axis to the minor axis k = 1.5-2.5. In this embodiment, the ratio of the major axis to the minor axis is 2:1.

[0024] The sharp corner tail of the closed curve is the intersection point C of the two circular arcs. The centers of the two circles where the two circular arcs are located are the same. The distance h between the two centers is a + R2-R1, R1 is the radius of the circle where the circular arc AC is located, R2 is the radius of the circle where the circular arc BC is located, R2 = β⋅R1, and the ratio coefficient β = 1.5-2.5. Thus, a capillary heat exchange tube similar to an airfoil is constructed. In this embodiment, R1:R2 = 3:4.

[0025] On the same vertical cross section, the contour lines of the irregular cross sections of the two capillary heat exchanger tubes in the middle of the capillary heat exchanger tube pair are two centrally symmetrical closed curves. The point C at the sharp end of the cross section contour line ABC of one capillary heat exchanger tube is the same as the vertical projection point of the sharp end of the cross section contour line A'B'C' of the other capillary heat exchanger tube. The distance between the two sharp end points is l1=λ⋅a, and the scaling factor λ=0.5~1.0. In this embodiment, λ=0.8.

[0026] The interval between two adjacent capillary heat exchange tubes in the capillary heat exchange tube assembly is l2=γ·l1, and the proportionality coefficient γ=1.0~1.5 (as shown in the figure, that is, the interval between the cross-sectional outline ABC of one capillary heat exchange tube and the cross-sectional outline A"B"C" of another capillary heat exchange tube on the same vertical section). In this embodiment, γ=1.2.

[0027] In the capillary heat exchanger assembly, on the same vertical cross section, the arc head positions of the cross section contour lines of two adjacent capillary heat exchangers correspond, and the horizontal projection of the elliptical arc portion in the arc is the same; the interval between two adjacent capillary heat exchangers is l3=δ⋅l1, and the proportionality coefficient δ=0.5~0.8.

[0028] In this embodiment, the airfoil-shaped cross-section microtubes are arranged in the following direction: Figure 5 As shown, the larger end of the cross-section typically faces the inlet direction of the fluid outside the tube, while the smaller end typically faces the outlet direction. This arrangement helps to minimize air resistance. The dashed line in the figure represents the flow path of the fluid inside the heat exchanger shell. It can be seen that this design increases the flow distance of the fluid, further improving the heat exchange effect.

[0029] Airfoil-shaped capillary heat exchange tubes satisfy the following relationship: and .in, To balance the pressure, The pressure of the fluid (gas or liquid) above the wing. The velocity of the fluid above the wing. The mass pressure below the wing. The velocity of the fluid under the wing. The density of the fluid. Airfoil-shaped capillary heat exchange tubes were designed. ,therefore Therefore, the airfoil-shaped cross-section reduces the pressure drop on the fluid side, accelerates the fluid flow rate, and thus improves heat exchange efficiency.

[0030] The finless microtube heat exchanger with an airfoil-shaped cross-section provided in the embodiments of the present invention can minimize wind resistance as much as possible, thereby reducing pressure loss and improving the overall efficiency of the refrigeration system.

[0031] The above merely preferred embodiments of the present application and are not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application. The above is merely the preferred embodiments of the present application, and it should be pointed out that, for ordinary skilled in the art, without departing from the technical principles of the present application, a number of improvements and variations can be made, and these improvements and variations should be considered as the protection scope of the present application.

Claims

1. A micro-channel heat exchanger with special-shaped cross-section, comprising a shell and a capillary heat exchange tube component, the shell being provided with a fluid inlet and a fluid outlet on opposite sides, and the capillary heat exchange tube component being arranged in the shell; characterized in that: the capillary heat exchange tube component comprises a plurality of capillary heat exchange tube assemblies, each capillary heat exchange tube assembly comprising a plurality of capillary heat exchange tube pairs arranged in parallel, and the plurality of capillary heat exchange tube pairs of the same capillary heat exchange tube assembly being vertically projected on the same plane; each capillary heat exchange tube pair comprises two capillary heat exchange tubes with the same shape, the capillary heat exchange tube being a metal cylindrical tube with a special-shaped cross-section, the special-shaped cross-section having a contour line formed by two circular arc lines and an elliptical arc line, and the hydraulic diameter of the contour line being less than or equal to 2 mm; the arc head of the contour line is a half circumference of a positive ellipse, the starting point A is the highest point of the positive ellipse, the ending point B is the lowest point of the positive ellipse, the straight line AB is the minor axis a of the positive ellipse, the major axis b of the positive ellipse is k·a, and the ratio k of the major axis to the minor axis is 1.5-2.5; the sharp corner tail of the contour line is the intersection point C of the two circular arc lines, the two circular arc lines are located on two circles with the same vertically projected center, the distance h between the two centers is a+R2-R1, R1 is the radius of the circle where the circular arc line AC is located, R2 is the radius of the circle where the circular arc line BC is located, R2=β·R1, and the ratio coefficient β is 1.5-2.5; on the same vertical cross-section, the contour lines of the special-shaped cross-sections of the two capillary heat exchange tubes in the capillary heat exchange tube pair are two center-symmetrical closed curves, the vertically projected point of the sharp corner tail point C of the cross-sectional contour line ABC of one capillary heat exchange tube is the same as the vertically projected point of the sharp corner tail point C' of the cross-sectional contour line A'B'C' of the other capillary heat exchange tube, the distance l1 between the two sharp corner tail points is λ·a, and the ratio coefficient λ is 0.5-1.0; all the capillary heat exchange tubes are connected in parallel, one end of each capillary heat exchange tube is connected to a working fluid inlet chamber, the other end is connected to a working fluid outlet chamber, and the working fluid inlet of the working fluid inlet chamber and the working fluid outlet of the working fluid outlet chamber are arranged at opposite corners of the capillary heat exchange tube component; the spacing l2 between the upper and lower adjacent two capillary heat exchange tubes of one capillary heat exchange tube assembly is γ·l1, and the ratio coefficient γ is 1.0-1.5; on the vertical cross-section of the capillary heat exchange tube component, the arc head positions of the cross-sectional contour lines of the left and right adjacent two capillary heat exchange tubes correspond to each other, and the horizontally projected elliptical arc line parts of the arc lines are the same; the spacing l3 between the left and right adjacent two capillary heat exchange tubes is δ·l1, and the ratio coefficient δ is 0.5-0.

8. ​ ​ ​ ​ ​ ​ 2. A microchannel heat exchanger of non-circular cross section as claimed in claim 1, wherein: ​ 3. A microchannel heat exchanger of non-circular cross section as claimed in claim 1, wherein: ​

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