A high temperature compact microchannel heat exchanger

Abstract

The present invention provides a high-temperature compact microchannel heat exchanger, which belongs to the field of high-temperature heat exchange. The microchannel heat exchanger includes a heat exchange medium inlet pipe, a primary flow distribution pipe, a secondary flow distribution pipe, a microchannel flat tube, a primary flow manifold, a secondary flow manifold and a heat exchange medium outlet pipe. The present invention achieves a design of high heat exchange efficiency and compact space structure through the internal heat exchange flow structure design. Compared with the traditional heat exchanger structure, the heat exchanger described in the present invention has high heat exchange efficiency, high temperature tolerance, uniform heat exchange, large equivalent heat exchange area, compact heat exchange structure design, and can tolerate a maximum temperature range of 1000℃~2500℃, and a maximum pressure range of 20MPa~40Mpa. It is suitable for application scenarios such as high pressure, high temperature, and compact space heat exchange.

Description

Technical Field

[0001] The invention belongs to the field of high-temperature heat exchange, and in particular relates to a microchannel annular heat exchanger using liquid metal as a heat exchange medium. Background Art

[0002] There are many types of existing heat exchangers, each with its own characteristics. According to the heat transfer principle, they can be divided into: partition heat exchangers, heat storage heat exchangers, fluid-connected indirect heat exchangers, direct contact heat exchangers, and compound heat exchangers, etc.; according to the structure, they can be divided into: floating head heat exchangers, fixed tube plate heat exchangers, U-shaped tube plate heat exchangers, and plate heat exchangers, etc. The shell and tube heat exchanger has a strong structure, is reliable, has strong adaptability, is easy to manufacture, and can withstand high pressure and temperature, but its heat transfer efficiency and compact structure are not as good as other new heat exchangers. The coil heat exchanger has a simple structure, low cost, and low operational sensitivity, but the flow rate of the fluid outside the tube is very small, so the heat transfer coefficient is small, the heat transfer efficiency is low, and the required heat transfer area is large. The shell and tube heat exchanger has a simple structure and a high heat transfer coefficient, but the metal consumption is large and the maintenance and cleaning are troublesome. The tube plate heat exchanger has a large heat transfer area, high heat transfer efficiency, and is easy to manufacture, but the flow resistance is large, the flow channel is easy to clog, and the pressure resistance is worse than that of the tube heat exchanger. The working temperatures of common existing heat exchangers vary greatly. The maximum temperature resistance of floating head heat exchangers is about 400℃ and the pressure resistance is about 6.4MPa; the working temperature of plate heat exchangers is between -30℃ and 180℃, and the maximum pressure is about 1.6MPa; plate-fin heat exchangers can be used for heat exchange at a temperature of 1000K if appropriate materials are selected. Existing heat exchangers are usually designed for different applicable occasions, and it is difficult to take into account the requirements of multiple parameters such as working temperature, heat exchange medium, structural compactness, flow pressure drop, etc. In addition, under high temperature conditions, due to the limitations of the use space and material properties, the heat exchange area of ​​common heat exchangers is difficult to meet the heat exchange requirements, and special structural design is required to increase the compactness of the structure.

[0003] In view of the above problems, the present invention proposes a high-temperature microchannel heat exchanger, which achieves a design of high heat exchange efficiency and compact space structure through the design of internal heat exchange flow structure.

[0004] Compared with the traditional heat exchanger structure, the heat exchanger described in the present invention has high heat exchange efficiency, high temperature tolerance, uniform heat exchange, large equivalent heat exchange area, and compact heat exchanger structure design, which is suitable for application scenarios such as high pressure, high temperature, and compact space heat exchange. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a heat exchanger with high heat exchange efficiency, compact structure and suitable for use in tube-type or ring-type channels. The heat exchanger is a composite heat exchanger that uses liquid metal as a heat transfer medium and uses microchannels for heat transfer.

[0006] The technical solution of the present invention is:

[0007] A high-temperature compact microchannel heat exchanger comprises a heat exchange medium inlet pipe, a primary flow distribution pipe, a secondary flow distribution pipe, a microchannel flat tube, a primary flow manifold, a secondary flow manifold and a heat exchange medium outlet pipe.

[0008] The microchannel flat tube is a flat tube with openings at both ends. The opening ends of the plurality of microchannel flat tubes are equally spaced along the circumferential direction, and the circumferential distribution angle is 0° to 180°, forming a cylindrical structure.

[0009] The primary flow distribution pipe and the secondary flow manifold are respectively located at the two ends of the cylindrical structure; the primary flow distribution pipe and the secondary flow manifold are both annular tubes, and an equal number of through holes are evenly spaced along the circumferential direction on the surfaces facing the cylindrical structure. The number of through holes, microchannel flat tubes, secondary flow distribution pipes and primary flow manifolds is the same. The secondary flow distribution pipe and the primary flow manifold are both open at one end and closed at the other end, and their lengths are consistent with the length of the open end of the microchannel flat tube; both are provided with grooves and slits in the length direction for drainage of heat exchange working fluids. The open ends of the secondary flow distribution pipe and the primary flow manifold are respectively connected to the through holes on the primary flow distribution pipe and the secondary flow manifold; and the grooves and slits of the secondary flow distribution pipe and the primary flow manifold are respectively connected to the open ends of the microchannel flat tubes located outside the cylindrical structure and the open ends located inside the cylindrical structure.

[0010] The microchannel flat tube is evenly provided with multiple partitions along the length direction of the secondary flow distribution pipe, and a heat exchange medium flow channel is formed between adjacent partitions, and the heat exchange medium flows in the flow channel and exchanges heat. The hydraulic diameter of the cross section of the microchannel flat tube flow channel does not exceed 12mm.

[0011] The channels between adjacent microchannel flat tubes form a heating flow channel for the fluid to be heated. The two ends of the heating flow channel are a heating inlet and a heating outlet, respectively. The heating inlet is located on the secondary flow manifold side, and the heating outlet is located on the primary flow distribution pipe side.

[0012] The heat exchange medium inlet pipe is connected to the primary flow distribution pipe. The secondary flow manifold is circumferentially connected to the heat exchange medium outlet pipe, and the heat exchange medium flows out from the heat exchange medium outlet pipe.

[0013] After the high-temperature heat exchange medium enters from the heat exchange medium inlet pipe, it passes through the primary flow distribution pipe and the secondary flow distribution pipe for flow distribution in sequence, and then enters the microchannel flat tube along the groove of the secondary flow distribution pipe for flow and heat exchange, and then the heat exchange medium flow is collected by the primary flow manifold and the secondary flow manifold in sequence, and finally flows out through the heat exchange medium outlet pipe. The fluid to be heated flows in through the front heating inlet, and flows out from the rear heating outlet after heat exchange in the heat exchanger.

[0014] Furthermore, the manufacturing materials of the heat exchange medium inlet pipe, primary flow distribution pipe, secondary flow distribution pipe, microchannel flat tube, primary flow manifold, secondary flow manifold and heat exchange medium outlet pipe have high temperature resistance and good thermal conductivity, including alloy materials such as tantalum-tungsten alloy, nickel-tungsten alloy, titanium-tungsten alloy, nickel-tantalum alloy, niobium-tungsten alloy or niobium-tantalum alloy, and composite materials such as silicon carbide.

[0015] Furthermore, the heat exchange medium is a liquid metal material having heat exchange capacity and high thermal conductivity under high temperature conditions, including liquid lithium, liquid sodium, liquid potassium, liquid rubidium or liquid cesium.

[0016] Furthermore, the cross-sectional shape of a single flow channel of the microchannel flat tube includes other closed curve shapes such as rectangle, circle or triangle; the shape of the groove seam on the secondary flow distribution pipe includes other closed curve shapes such as rectangle or circle.

[0017] Furthermore, there are 60 microchannel flat tubes, and the circumferential distribution angle is 6°.

[0018] Furthermore, there are four heat exchange medium outlet pipes, and the circumferential distribution angle is 90°.

[0019] Beneficial effects of the invention: The invention proposes a high-temperature compact microchannel heat exchanger, which realizes the design of high heat exchange efficiency and compact space structure through the design of internal heat exchange flow structure. Compared with the traditional heat exchanger structure, the heat exchanger described in the invention has high heat exchange efficiency, high temperature tolerance, uniform heat exchange, large equivalent heat exchange area, compact heat exchange structure design, and can tolerate a maximum temperature range of 1000℃~2500℃, and a maximum pressure range of 20MPa~40Mpa, which is suitable for high pressure, high temperature, compact space heat exchange and other application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of a high-temperature compact microchannel heat exchanger of the present invention;

[0021] Figure 2 It is a front view of the high temperature compact microchannel heat exchanger of the present invention;

[0022] Figure 3 Schematic diagram of the groove seam structure of the secondary flow distribution pipe in Example 1 and Example 2 of the present invention;

[0023] Figure 4 It is a schematic diagram of the microchannel flat tube structure in Example 1 and Example 2 of the present invention;

[0024] Figure 5 It is a flow channel structure diagram of the microchannel flat tube chamber in Example 1 and Example 2 of the present invention.

[0025] In the figure: 1 heat exchange medium inlet pipe; 2 primary flow distribution pipe; 3 secondary flow distribution pipe; 4 microchannel flat tube; 5 primary flow manifold; 6 secondary flow manifold; 7 heat exchange medium outlet pipe; 8 heating inlet; 9 heating outlet. DETAILED DESCRIPTION

[0026] The present invention is further described below in conjunction with embodiments and drawings.

[0027] The working principle of the present invention is: the high-temperature liquid medium enters from the heat exchange medium inlet pipe, and after the flow distribution is carried out in the primary flow distribution pipe and the secondary flow distribution pipe, it enters the microchannel flat tube channel for flow and heat exchange, and the medium after heat exchange is collected by the primary flow manifold and the secondary flow manifold, and finally flows out from the heat exchange medium outlet pipe. The fluid to be heated flows in from the heating inlet, heat exchanges in the heating flow channel, and the heated fluid flows out from the heating outlet, realizing the heat exchange process of the entire heat exchanger.

[0028] Embodiment 1:

[0029] like Figure 1 As shown, a high-temperature compact microchannel heat exchanger includes a heat exchange medium inlet pipe 1, a primary flow distribution pipe 2, a secondary flow distribution pipe 3, a microchannel flat tube 4, a primary flow manifold 5, a secondary flow manifold 6, a heat exchange medium outlet pipe 7, a heating inlet 8 and a heating outlet 9.

[0030] The microchannel flat tubes 4 are flat tubes with openings at both ends, and there are 60 of them in total. The opening ends of the 60 microchannel flat tubes 4 are distributed in a ring shape in space, and the spatial distribution angle is 6°, forming a cylindrical structure. The microchannel flat tubes 4 are evenly provided with multiple partitions along the opening direction, and rectangular flow channels are formed between adjacent partitions. A total of 48 flow channels are provided along the length direction of the secondary flow distribution pipe 3, and the flow channel interval is 20 mm.

[0031] High-temperature liquid lithium metal flows in from the heat exchange medium inlet pipe 1, and then the flow is distributed by the primary flow distribution pipe 2 connected to the heat exchange medium inlet pipe 1. The primary flow distribution pipe 2 is evenly and evenly provided with through holes at equal intervals along the circumference, and one end of the secondary flow distribution pipe 3 is connected to the through hole of the primary flow distribution pipe 2 by welding. The fluid flows into the chamber flow channel in the microchannel flat tube 4 from the rectangular groove seam opened in the length direction of the secondary flow distribution pipe 3, and then is collected by the primary flow manifold 5 through the rectangular groove seam opened in the length direction of the primary flow manifold 5, and then enters the secondary flow manifold 6 connected to one end of the primary flow manifold 5, and finally flows out from the four heat exchange medium outlet pipes 7 circumferentially connected to the secondary flow manifold 6, realizing the cooling process of the liquid lithium metal.

[0032] The air flows in from the heating inlet 8, exchanges heat in the heating flow channel, and the heated air flows out from the heating outlet 9, thus achieving the temperature increase process of the air in the heat exchanger.

[0033] In particular, the heat exchange medium is selected as high temperature liquid metal lithium, and the fluid to be heated is selected as air. The heat exchange medium inlet pipe 1, the primary flow distribution pipe 2, the secondary flow distribution pipe 3, the microchannel flat pipe 4, the primary flow manifold 5, the secondary flow manifold 6 and the heat exchange medium outlet pipe 7 are all made of tantalum tungsten alloy.

[0034] Embodiment 2:

[0035] like Figure 1 As shown, a high-temperature compact microchannel heat exchanger includes a heat exchange medium inlet pipe 1, a primary flow distribution pipe 2, a secondary flow distribution pipe 3, a microchannel flat tube 4, a primary flow manifold 5, a secondary flow manifold 6, a heat exchange medium outlet pipe 7, a heating inlet 8 and a heating outlet 9.

[0036] The microchannel flat tubes 4 are flat tubes with openings at both ends, and there are 60 of them in total. The opening ends of the 60 microchannel flat tubes 4 are distributed in a ring shape in space, and the spatial distribution angle is 6°, forming a cylindrical structure. The microchannel flat tubes 4 are evenly provided with multiple partitions along the opening direction, and rectangular flow channels are formed between adjacent partitions. A total of 48 flow channels are provided along the length direction of the secondary flow distribution pipe 3, and the flow channel interval is 20 mm.

[0037] High-temperature liquid lithium metal flows in from the heat exchange medium inlet pipe 1, and then the flow is distributed by the primary flow distribution pipe 2 connected to the heat exchange medium inlet pipe 1. The primary flow distribution pipe 2 is evenly and evenly provided with through holes at equal intervals along the circumference, and one end of the secondary flow distribution pipe 3 is connected to the through hole of the primary flow distribution pipe 2 by welding. The fluid flows into the chamber flow channel in the microchannel flat tube 4 from the rectangular groove seam opened in the length direction of the secondary flow distribution pipe 3, and then is collected by the primary flow manifold 5 through the rectangular groove seam opened in the length direction of the primary flow manifold 5, and then enters the secondary flow manifold 6 connected to one end of the primary flow manifold 5, and finally flows out from the heat exchange medium outlet pipe 7, realizing the cooling process of the liquid lithium metal.

[0038] The high-temperature grease flows in from the heating inlet 8, exchanges heat in the heating flow channel, and the heated high-temperature grease flows out from the heating outlet 9, thus realizing the temperature increase process of the high-temperature grease in the heat exchanger.

[0039] The heat exchange medium inlet pipe 1, the primary flow distribution pipe 2, the secondary flow distribution pipe 3, the microchannel flat tube 4, the primary flow manifold 5, the secondary flow manifold 6 and the heat exchange medium outlet pipe 7 are made of tantalum-tungsten alloy.

[0040] The above embodiments are only used to illustrate the present invention and are not intended to limit the technical solutions described in the present invention; therefore, although the present invention has been described in detail in this specification with reference to the above embodiments, it should be understood by those skilled in the art that the present invention can still be modified or replaced by equivalents; and all technical solutions and improvements thereof that do not depart from the spirit and scope of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A high temperature compact microchannel heat exchanger, characterized in that: The microchannel heat exchanger comprises a heat exchange medium inlet pipe, a primary flow distribution pipe, a secondary flow distribution pipe, a microchannel flat tube, a primary flow manifold, a secondary flow manifold and a heat exchange medium outlet pipe; The microchannel flat tube is a flat tube with openings at both ends, and the opening ends of the plurality of microchannel flat tubes are equally spaced along the circumference, with a circumferential distribution angle of 0° to 180°, forming a cylindrical structure; The primary flow distribution pipe and the secondary flow manifold are respectively located at the two ends of the cylindrical structure; the primary flow distribution pipe and the secondary flow manifold are both annular tubes, and the surfaces facing the cylindrical structure of the two are evenly and evenly provided with an equal number of through holes at equal intervals along the circumferential direction; the secondary flow distribution pipe and the primary flow manifold are both open at one end and closed at the other end, and the lengths are consistent with the lengths of the open ends of the microchannel flat tubes; both are provided with grooves and slits in the length direction for guiding the heat exchange medium; the open ends of the secondary flow distribution pipe and the primary flow manifold are respectively connected to the through holes on the primary flow distribution pipe and the secondary flow manifold; and the grooves and slits of the secondary flow distribution pipe and the primary flow manifold are respectively connected to the open ends of the microchannel flat tubes located outside the cylindrical structure and the open ends located inside the cylindrical structure; The microchannel flat tube is evenly provided with a plurality of partitions along the length direction of the secondary flow distribution pipe, and a heat exchange medium flow channel is formed between adjacent partitions, and the heat exchange medium flows in the flow channel and performs heat exchange; the hydraulic diameter of the cross section of the microchannel flat tube flow channel does not exceed 12 mm; The channels between adjacent microchannel flat tubes form a heating flow channel for the fluid to be heated, and the two ends of the heating flow channel are respectively a heating inlet and a heating outlet, wherein the heating inlet is located on the side of the secondary flow manifold, and the heating outlet is located on the side of the primary flow distribution pipe; The heat exchange medium inlet pipe is connected to the primary flow distribution pipe; the secondary flow manifold is circumferentially connected to the heat exchange medium outlet pipe; After the high-temperature heat exchange medium enters from the heat exchange medium inlet pipe, it passes through the primary flow distribution pipe and the secondary flow distribution pipe in sequence for flow distribution, and then enters the microchannel flat tube along the groove of the secondary flow distribution pipe for flow and heat exchange, and then the heat exchange medium flow is collected by the primary flow manifold and the secondary flow manifold in sequence, and finally flows out through the heat exchange medium outlet pipe; the fluid to be heated flows in through the heating inlet, and flows out from the heating outlet after heat exchange in the heat exchanger.

2. A high temperature compact microchannel heat exchanger according to claim 1, characterized in that: There are 60 microchannel flat tubes, and the circumferential distribution angle is 6°.

3. A high temperature compact microchannel heat exchanger according to claim 1 or 2, characterized in that: There are four heat exchange medium outlet pipes, and the circumferential distribution angle is 90°.

4. A high temperature compact microchannel heat exchanger according to claim 1 or 2, characterized in that: The cross-sectional shape of a single flow channel of the microchannel flat tube includes a rectangle, a circle or a triangle; the shape of the groove seam on the secondary flow distribution pipe includes a rectangle or a circle.

5. A high temperature compact microchannel heat exchanger according to claim 3, characterized in that: The cross-sectional shape of a single flow channel of the microchannel flat tube includes a rectangle, a circle or a triangle; the shape of the groove seam on the secondary flow distribution pipe includes a rectangle or a circle.

6. A high temperature compact microchannel heat exchanger according to claim 1, 2 or 5, characterized in that: The materials of the heat exchange medium inlet pipe, primary flow distribution pipe, secondary flow distribution pipe, microchannel flat tube, primary flow manifold, secondary flow manifold and heat exchange medium outlet pipe include tantalum-tungsten alloy, nickel-tungsten alloy, titanium-tungsten alloy, nickel-tantalum alloy, niobium-tungsten alloy, niobium-tantalum alloy or silicon carbide.

7. A high temperature compact microchannel heat exchanger according to claim 3, characterized in that: The materials of the heat exchange medium inlet pipe, primary flow distribution pipe, secondary flow distribution pipe, microchannel flat tube, primary flow manifold, secondary flow manifold and heat exchange medium outlet pipe include tantalum-tungsten alloy, nickel-tungsten alloy, titanium-tungsten alloy, nickel-tantalum alloy, niobium-tungsten alloy, niobium-tantalum alloy or silicon carbide.

8. A high temperature compact microchannel heat exchanger according to claim 4, characterized in that: The materials of the heat exchange medium inlet pipe, primary flow distribution pipe, secondary flow distribution pipe, microchannel flat tube, primary flow manifold, secondary flow manifold and heat exchange medium outlet pipe include tantalum-tungsten alloy, nickel-tungsten alloy, titanium-tungsten alloy, nickel-tantalum alloy, niobium-tungsten alloy, niobium-tantalum alloy or silicon carbide.

9. A high temperature compact microchannel heat exchanger according to claim 1, 2, 5, 7 or 8, characterized in that: The high-temperature heat exchange medium includes liquid lithium, liquid sodium, liquid potassium, liquid rubidium or liquid cesium.

10. A high temperature compact microchannel heat exchanger according to claim 6, characterized in that: The high-temperature heat exchange medium includes liquid lithium, liquid sodium, liquid potassium, liquid rubidium or liquid cesium.

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