Radiating core body for tubular heat exchanger and radiator

Abstract

The invention discloses a radiating core body for a tubular heat exchanger and a radiator. Comprising an end plate (1), connecting holes (2) are distributed in the end plate (1), and the connecting holes (2) are in expanded connection with a radiating pipe (3). High-pressure reliable sealing between the core body and the end plate of the aluminum alloy shell-and-tube heat exchanger is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of high-pressure heat exchangers and seals, and in particular relates to a heat dissipation core and a radiator for a shell-and-tube heat exchanger. Background Art

[0002] Shell and tube heat exchangers are easy to manufacture, have low production costs, a wide range of material selection, are easy to clean, have strong adaptability, large processing capacity, operate reliably, and can adapt to high temperature and high pressure. They are still widely used in high-pressure environments in aero engines, chemical industry and other fields.

[0003] With the rapid development of the modern aviation industry, the heat dissipation demand for aircraft and engines is increasing. As the main component for heat dissipation of airborne equipment, heat exchangers have higher requirements for their design optimization. Shell and tube heat exchangers for aircraft engines have more prominent requirements for product pressure bearing capacity, lightweight, and miniaturization. Aluminum alloy materials show excellent characteristics in lightweight, and due to the particularity of aviation application scenarios, the equivalent diameter (inner diameter) of the heat dissipation pipe of the shell and tube heat exchanger is in the range of 1 to 5 mm. How to solve the sealing connection problem of high-strength aluminum alloy and small-channel heat exchangers is the key to solving the high-pressure lightweight heat exchanger for aircraft engines.

[0004] At present, the connection and sealing between the core and the end plate of the aluminum alloy shell and tube heat exchanger in China are mainly brazing, argon arc welding, and expansion joint without expansion sleeve. Among the above processing methods, the overall brazing requires high-temperature brazing of the core as a whole, and the material strength and corrosion resistance are reduced after brazing; argon arc welding is only suitable for industrial shell and tube heat exchangers with a diameter greater than 10mm; the yield of expansion joint without expansion sleeve is low, and it is easy to leak after long-term use and is not resistant to high pressure. Summary of the invention

[0005] The purpose of the present invention is to provide a heat dissipation core and a radiator for a shell-and-tube heat exchanger. The present invention can achieve high-pressure reliable sealing between the core and the end plate of the aluminum alloy shell-and-tube heat exchanger.

[0006] The technical solution of the present invention is: a heat dissipation core for a shell-and-tube heat exchanger, comprising an end plate, the end plate is provided with connection holes, and the connection holes are expansion-connected with the heat dissipation tubes.

[0007] In the aforementioned heat dissipation core for shell-and-tube heat exchanger, the end plate and heat dissipation tube are both made of aluminum alloy, the strength of the end plate aluminum alloy is not less than 380MPa, the yield strength and elongation of the heat dissipation tube aluminum alloy are 150MPa~210MPa and 0.5% respectively, the outer diameter of the heat dissipation tube is 2~5mm, and the wall thickness is 0.3~0.4mm; the minimum margin L1 between adjacent connecting holes is 0.5~0.6mm; the clearance between the connecting hole and the heat dissipation tube before expansion is 0.035~0.06mm, and the expansion length L2 of the connecting hole and the heat dissipation tube is 7~10mm.

[0008] In the aforementioned heat dissipation core for the shell-and-tube heat exchanger, a stepped hole is provided at the outer end opening of the connecting hole.

[0009] In the aforementioned heat dissipation core for the shell-and-tube heat exchanger, the diameter of the step hole is 0.04 to 0.1 mm larger than the connecting hole, and the depth of the step hole is 1 mm.

[0010] In the heat dissipation core for the aforementioned shell-and-tube heat exchanger, an end plate end surface facing away from the expansion joint side is provided with an inwardly concave arch structure.

[0011] In the aforementioned heat dissipation core for shell-and-tube heat exchanger, the maximum diameter D of the expansion head of the expansion rod used for expansion connection is 1mm~4mm, the expansion sleeve used is made of aluminum alloy, and the hardness of the expansion sleeve aluminum alloy is 75~100HV; the wall thickness of the expansion sleeve is 0.3mm; the matching clearance between the expansion sleeve and the inner hole of the heat dissipation tube is 0.02~0.1mm.

[0012] In the heat dissipation core for the aforementioned shell-and-tube heat exchanger, after expansion, the outer wall of the heat dissipation tube at the step hole is squeezed and contacts the inner wall of the step hole.

[0013] A radiator composed of the above-mentioned heat dissipation core includes a dome-shaped cover covering the end surface of the expansion joint side of the end plate. The connection structure between the dome-shaped cover and the end plate is a falcon groove sealing structure. The locking bottom structure size of the falcon groove sealing structure is not less than 1mm×1mm, and the fitting clearance is 0~0.12mm.

[0014] In the aforementioned heat sink, the connection structure is fixed by vacuum electron beam welding.

[0015] In the aforementioned radiator, the dome of the dome-shaped cover is connected to the end plate via bolts.

[0016] The advantages of the present invention are: the present invention proposes a built-in expansion sleeve core-pulling mechanical expansion sealing structure, and at the same time cooperates with the end plate arch structure to achieve high-pressure reliable sealing between the core and the end plate of the aluminum alloy shell and tube heat exchanger. The processing methods of the present invention are all mechanical cold processing, which retains the original strength and corrosion resistance of the material itself, and can make the aluminum alloy shell and tube heat exchanger suitable for working environments with pressures up to 20MPa, and improve the reliability of the product.

[0017] The present invention explores the expansion process parameters of the above-mentioned micro-channel heat dissipation pipe by combining simulation and experiment. A macroscopic dynamics simulation model is established for the expansion process, a contact mechanics simulation model is established for the microscopic interface, and sensitive factors are analyzed for the geometric parameters, material parameters, and expansion process of the parts involved in the expansion process to screen out a suitable matching combination. The selected matching combination is verified by a large number of actual process tests, repeatability verification, etc., to obtain the above-mentioned key process parameters and methods.

[0018] The pressure bearing capacity of the conventional brazed aluminum alloy heat exchanger is about 10 MPa, while the pressure bearing capacity of the expansion-jointed aluminum alloy heat exchanger of the present invention is about 20 MPa. Moreover, under the same pressure bearing capacity, the weight is reduced by more than 20%.

[0019] Compared with the traditional assembled expansion heat exchanger, the present invention adopts the electron beam welding method, eliminating the end plate peripheral bolts, flange and other structures, and the maximum outer diameter can be reduced by more than 20%, meeting the miniaturization requirements of aviation heat exchangers. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structure of the internal expansion sleeve core-pulling mechanical expansion joint sealing structure of the present invention;

[0021] Figure 2 This is a schematic diagram of the expansion process;

[0022] Figure 3 Schematic diagram of the expansion sequence. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0024] The features and illustrative embodiments of various aspects of the present invention will be described in detail below. In the detailed description below, many specific details are proposed to provide a comprehensive understanding of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present invention by illustrating examples of the present invention. The present invention is by no means limited to any specific settings and methods proposed below, but covers any improvements, replacements and modifications of structures, methods, devices without departing from the spirit of the present invention. In the accompanying drawings and the following description, known structures and technologies are not shown to avoid unnecessary ambiguity in the present invention.

[0025] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other, and the embodiments can refer to and quote each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0026] Example 1. A heat dissipation core and a heat dissipation device for a shell-and-tube heat exchanger, see Figure 1-3, including an end plate 1, on which connection holes 2 are distributed, and the connection holes 2 are expanded with the heat dissipation tube 3. Through the expansion, the connection holes 2 and the heat dissipation tube 3 are plastically extruded and deformed, and a pre-tightening force is formed to form a seal. This structure can avoid the influence of high temperature of brazing sealing on material strength.

[0027] The aforementioned end plate 1 and heat dissipation tube 3 are both made of aluminum alloy. The strength of the aluminum alloy of the end plate 1 is not less than 380MPa. The yield strength and elongation of the aluminum alloy of the heat dissipation tube 3 are 150MPa~210MPa and 0.5% respectively. The outer diameter of the heat dissipation tube 3 is 2~5mm, and the wall thickness is 0.3~0.4mm; the minimum margin distance L1 between adjacent connecting holes 2 is 0.5~0.6mm; the clearance between the connecting hole 2 and the heat dissipation tube 3 before expansion is 0.035~0.06mm, and the expansion length L2 of the connecting hole 2 and the heat dissipation tube 3 is 7~10mm.

[0028] A stepped hole 4 is provided at the outer end of the aforementioned connecting hole 2.

[0029] The diameter of the aforementioned step hole 4 is 0.04-0.1 mm larger than that of the connecting hole 2, and the depth of the step hole 4 is 1 mm.

[0030] The end surface of the end plate 1 away from the expansion joint side is provided with a concave arch structure 5. The arch structure can increase the ability of the end plate 1 to resist compression deformation.

[0031] The maximum diameter D of the expansion head 8 of the expansion rod 6 used for expansion connection is 1mm~4mm, the expansion sleeve 7 used is made of aluminum alloy, and the hardness of the aluminum alloy of the expansion sleeve 7 is 75~100HV; the wall thickness of the expansion sleeve 7 is 0.3mm; the matching clearance between the expansion sleeve 7 and the inner hole of the heat dissipation tube 3 is 0.02~0.1mm.

[0032] After expansion, the outer wall of the heat dissipation tube 3 at the step hole 4 is squeezed and contacts the inner wall of the step hole 4. During the expansion process, the excess metal of the heat dissipation tube 3 will be filled into the step hole 4 to form a secondary seal, and the heat dissipation tube 3 and the end plate form a T-shaped step seal, which increases the axial pull-off resistance of the expansion sleeve, thereby increasing the pressure bearing capacity of the cavity. The expansion sleeve, heat dissipation tube and end plate should be made of aluminum alloy, and the hardness of the heat dissipation tube should be the lowest among the three.

[0033] The radiator composed of the above-mentioned heat dissipation core includes a dome cover 10 covering the end surface of the expansion side of the end plate 1. The connection structure between the dome cover 10 and the end plate 1 is a falcon groove sealing structure. The lock bottom structure size of the falcon groove sealing structure is not less than 1mm×1mm, and the matching clearance is 0-0.12mm. The falcon groove structure should be set at the connection to prevent excess objects from entering the cavity during welding and being difficult to remove.

[0034] The connection structure is fixed by vacuum electron beam welding. Low-heat welding is used to reduce the impact on the sealing of the heat dissipation core. Compared with the traditional bolt assembly method, the welding method can effectively reduce weight and save space.

[0035] The dome of the dome cover 10 is connected to the end plate 1 via bolts 11. The end plate and the cover are screwed together with bolts 11 to increase their ability to resist compression deformation.

[0036] The aforementioned expansion method of the heat dissipation core comprises the following steps:

[0037] S1. Insert the end of the heat pipe 3 into the connecting hole 2;

[0038] S2. The expansion rod 6 is installed into the expansion sleeve 7 to form an expansion assembly;

[0039] S3. Install the expansion assembly into the inner hole of the heat dissipation tube 3;

[0040] S4. The expansion sleeve 7 is axially limited, and the expansion rod 6 is pulled to pull the expansion head 8 out of the expansion sleeve 7 along the axial direction to extrude the expansion sleeve 7 and the heat dissipation tube 3 for plastic deformation to complete the expansion connection; this step is completed using an expansion gun;

[0041] S5. Remove the expansion cap 9 of the expansion sleeve 7.

[0042] In step S4, when expanding, expand in the order of odd / even rows. In actual operation, when expanding the tube holes, expand every other row, and then return to expand again, such as Figure 2 As shown, when expansion joints are performed, the 1st row, 3rd row, 5th row... should be expanded first, and then the 2nd row, 4th row, 6th row... should be expanded to avoid mutual interference that affects the expansion joint effect.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the field can easily think of various equivalent modifications or substitutions within the technical scope disclosed by the present invention, and these modifications or substitutions should all be covered within the protection scope of the present invention.

Claims

1. A heat dissipation core for a shell-and-tube heat exchanger, characterized in that: It comprises an end plate (1), on which connection holes (2) are distributed, and the connection holes (2) are expansion-connected with the heat dissipation pipes (3).

2. The heat dissipation core for a shell-and-tube heat exchanger according to claim 1, characterized in that: The end plate (1) and the heat dissipation pipe (3) are both made of aluminum alloy. The strength of the aluminum alloy of the end plate (1) is not less than 380 MPa. The yield strength and elongation of the aluminum alloy of the heat dissipation pipe (3) are 150 MPa to 210 MPa and 0.5% respectively. The outer diameter of the heat dissipation pipe (3) is 2 to 5 mm, and the wall thickness is 0.3 to 0.4 mm. The minimum margin L1 between adjacent connecting holes (2) is 0.5 to 0.6 mm. The clearance between the connecting hole (2) and the heat dissipation pipe (3) before expansion is 0.035 to 0.06 mm, and the expansion length L2 of the connecting hole (2) and the heat dissipation pipe (3) is 7 to 10 mm.

3. The heat dissipation core for a shell-and-tube heat exchanger according to claim 1, characterized in that: A stepped hole (4) is provided at the outer end opening of the connecting hole (2).

4. The heat dissipation core for a shell-and-tube heat exchanger according to claim 3, characterized in that: The diameter of the step hole (4) is 0.04-0.1 mm larger than that of the connecting hole (2), and the depth of the step hole (4) is 1 mm.

5. The heat dissipation core for a shell-and-tube heat exchanger according to claim 1, characterized in that: The end surface of the end plate (1) facing away from the expansion joint side is provided with a concave arch structure (5).

6. The heat dissipation core for a shell-and-tube heat exchanger according to claim 1, characterized in that: The maximum diameter D of the expansion head (8) of the expansion rod (6) used for expansion connection is 1 mm to 4 mm, the expansion sleeve (7) used is made of aluminum alloy, and the hardness of the aluminum alloy of the expansion sleeve (7) is 75 to 100 HV; the wall thickness of the expansion sleeve (7) is 0.3 mm; and the matching clearance between the expansion sleeve (7) and the inner hole of the heat dissipation pipe (3) is 0.02 to 0.1 mm.

7. The heat dissipation core for a shell-and-tube heat exchanger according to claim 3, characterized in that: After the expansion connection, the outer wall of the heat dissipation pipe (3) at the step hole (4) is squeezed and contacts the inner wall of the step hole (4).

8. A radiator composed of the heat dissipation core according to any one of claims 1 to 7, characterized in that: It comprises a dome-shaped cover (10) covering the expansion-joined side end surface of the end plate (1); the connection structure between the dome-shaped cover (10) and the end plate (1) is a falcon groove sealing structure; the locking bottom structure size of the falcon groove sealing structure is not less than 1mm×1mm, and the matching clearance is 0-0.12mm.

9. The heat sink according to claim 8, characterized in that: The connection structure is fixed by vacuum electron beam welding.

10. The heat sink according to claim 8, characterized in that The dome of the dome-shaped cover (10) is connected to the end plate (1) via bolts (11).

Images