Thermal stress prevention mechanism of micro-channel heat exchanger of rail transit air conditioner

Abstract

The utility model discloses a thermal stress prevention mechanism of a micro-channel heat exchanger of a rail transit air conditioner, which comprises at least one flexible fixing group, the flexible fixing group comprises a connecting frame and a flexible connecting sleeve, the connecting frame is provided with at least one connecting groove sleeved at one end of the outer side of a core body, and the flexible connecting sleeve is sleeved at the other end of the outer side of the core body. The base of the connecting frame is connected with the outer side of the flexible connecting sleeve in a sleeving mode and is flexibly connected with the rigid sleeve through the flexible connecting sleeve so that the base can be fixed to a preset position through a bolt and used for elastically offsetting the stress of the core body in the transverse direction. When the core body is subjected to thermal deformation due to temperature change, the flexible connecting sleeve connected between the bolt and the connecting frame plays a role in flexibly buffering transverse deformation, and the core body is prevented from being damaged due to thermal stress.

Description

Technical Field

[0001] The utility model relates to the technical field of microchannel heat exchangers, in particular to a thermal stress prevention mechanism for a microchannel heat exchanger of a rail transit air conditioner. Background Art

[0002] In the rail transit air conditioner unit, the microchannel heat exchanger scheme is adopted. Since the microchannel heat exchanger is made of all-aluminum alloy structure, during the operation of the air conditioner, the temperature of the microchannel itself will rise very high. The existence of temperature difference will cause the aluminum alloy structure to expand and contract thermally. In the past, heat exchangers were all fixed rigidly by bolts. If the microchannel heat exchanger is also fixed rigidly, the aluminum alloy structure will encounter the problem of thermal stress during thermal expansion and contraction, resulting in problems such as cracks or local cracking damage in the structure itself or the welding area.

[0003] Therefore, there is still a need for a thermal stress prevention mechanism for a microchannel heat exchanger of a rail transit air conditioner to solve the above problems. [[ID=##]] Summary of the Utility Model

[0004] The utility model provides a thermal stress prevention mechanism for a microchannel heat exchanger of a rail transit air conditioner to solve the above problems.

[0005] The purpose of the utility model is achieved by the following technical solutions:

[0006] A thermal stress prevention mechanism for a microchannel heat exchanger of a rail transit air conditioner, comprising:

[0007] At least one flexible fixing group, the flexible fixing group includes a connecting frame and a flexible connecting sleeve. The connecting frame has at least one connecting groove at one end of the outer side of the socket core, and the base of the connecting frame is sleeved on the outer side of the flexible connecting sleeve and fixed at a preset position by a flexible connecting sleeve flexible connecting bolt, for elastically offsetting the stress of the core body in the transverse direction.

[0008] In one embodiment, in the thickness direction, at least part of the flexible connecting sleeve is sleeved between the bolt and the base of the connecting frame, at least part of the outer peripheral wall of the flexible connecting sleeve abuts against the inner wall of the through hole of the base of the connecting frame, and at least part of the inner peripheral wall of the flexible connecting sleeve abuts against the bolt.

[0009] In one embodiment, the shape of the connecting groove is an arc surface matching the shape of one end of the outer side of the heat exchanger, and the arc bottom end of the connecting groove is located below the center of the arc of the corresponding end of the outer side of the heat exchanger.

[0010] In one embodiment, the flexible connecting sleeve further includes a limiting part connected to the top of the flexible connecting sleeve. The outer diameter of the limiting part is larger than the outer diameter of the flexible connecting sleeve, and it is connected between the bottom of the bolt nut and the top of the base.

[0011] In one embodiment, the distance between two parallel annular surfaces of the limiting portion is 1-5 mm, and the wall thickness of the flexible connecting sleeve is 1-4 mm.

[0012] In one embodiment, the flexible connecting sleeve is made of rubber or silica gel and has a hardness of 30-70 SHA.

[0013] In one embodiment, a rigid sleeve connected between the bolt and the flexible connecting sleeve is further included, and the rigid sleeve is used to rigidly support the inner wall of the flexible connecting sleeve.

[0014] Compared with the prior art, the beneficial effects of the present utility model at least include:

[0015] The flexible fixing group is connected to one side or both sides of the core body. The connecting frame is sleeved on the outer periphery of one side of the core body, and the bottom of the connecting frame is connected to the bolt through the flexible connecting sleeve. When the core body undergoes thermal deformation due to temperature change, the flexible connecting sleeve connected between the bolt and the connecting frame plays a role in flexibly buffering the lateral deformation, avoiding damage to the solder joints at the connection points caused by the self-stress of the core body or damage to the structure itself. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is an assembly schematic diagram of the flexible fixing group and the core body according to an embodiment of the present utility model;

[0017] Figure 2 is a top view of the assembly of the flexible fixing group and the core body according to an embodiment of the present utility model;

[0018] Figure 3 is a partial cross-sectional view of the flexible fixing group and the core body according to an embodiment of the present utility model.

[0019] In the figure: 1. Flexible fixing group; 11. Connecting frame; 111. Connecting groove; 112. Base; 12. Flexible connecting sleeve; 13. Limiting portion; 2. Bolt; 3. Core body; 4. Rigid sleeve. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. Like reference numerals refer to like or similar structures in the figures, and thus their repeated description will be omitted.

[0021] The words expressing positions and directions described in the present utility model are all illustrated by taking the drawings as examples, but can be changed according to needs, and all the changes made are included in the protection scope of the present utility model.

[0022] Reference Figures 1-3 , the present utility model provides a thermal stress prevention mechanism for a microchannel heat exchanger of a rail transit air conditioner, including:

[0023] At least one flexible fixing group 1, the flexible fixing group 1 includes a connecting frame 11 and a flexible connecting sleeve 12. The connecting frame 11 has at least one connecting groove 111 sleeving the outer end of the core body 3, and the base 112 of the connecting frame 11 is sleeved on the outer side of the flexible connecting sleeve 12 and is fixed at a preset position through the flexible connecting sleeve 12 by a flexible connecting bolt 2, so as to elastically offset the stress of the core body 3 in the transverse direction. The connecting frame 11 includes two parts, one part is in a shape for docking with the outer side of the end of the core body 3, and the other part is connected to the base 112. A part of the connecting base 112 passes through the thickness direction through the bolt 2, and the flexible connecting sleeve 12 is located between the bolt 2 and the base 112. When the core body 3 is heated and its length expands due to heat, the flexible connecting sleeve 12 abuts between the connecting seat and the bolt 2, transversely offsetting the stress transmitted by the connecting seat, and preventing the core body 3 from expanding transversely and causing local cracking.

[0024] Preferably, in the thickness direction, at least part of the flexible connecting sleeve 12 is sleeved between the bolt 2 and the base 112 of the connecting frame 11, at least part of the outer peripheral wall of the flexible connecting sleeve 12 abuts the inner wall of the through hole of the base 112 of the connecting frame 11, and at least part of the inner peripheral wall of the flexible connecting sleeve 12 abuts the bolt 2. At least part of the flexible connecting sleeve 12 is located between the bolt 2 and the connecting frame 11, so as to transversely offset the stress of the core body 3 during transverse expansion and prevent local rupture caused by excessive stress.

[0025] Preferably, the shape of the connecting groove 111 is an arc surface matching the shape of the outer end of the heat exchanger, and the arc bottom end of the connecting groove 111 is located below the center of the arc of the corresponding outer end of the heat exchanger. The cross-sectional shape of the connecting groove 111 is circular arc, and the lowest point of the arc is located below the center of the end of the heat exchanger, which can tightly sleeve the core body 3 of the heat exchanger and prevent the core body 3 from falling off.

[0026] Preferably, it further includes a rigid sleeve 4 connected between the bolt 2 and the flexible connecting sleeve 12, and the rigid sleeve 4 is used to rigidly support the inner wall of the flexible connecting sleeve 12. The rigid sleeve 4 is inserted into the flexible connecting sleeve 12. During connection, it passes through the inside of the flexible connecting sleeve 12, supports the flexible connecting sleeve 12 inserted into the hole, then passes the bolt 2 through the inside of the flexible connecting sleeve 12 and tightens it at a preset position, and connects the base 112, playing a role in offsetting the internal stress of the core body.

[0027] Preferably, the flexible connecting sleeve 12 further includes a limiting portion 13 connected to the top of the flexible connecting sleeve 12. The outer diameter of the limiting portion 13 is larger than that of the flexible connecting sleeve 12, and it is connected between the bottom of the nut of the bolt 2 and the top of the base 112. The top of the flexible limiting sleeve is integrally formed. During connection, by pressing the bottom of the nut, the flexible connecting sleeve 12 is fixed to the bottom of the bolt 2, preventing the flexible connecting sleeve 12 from moving out of place in the vertical direction and failing to offset the buffer stress.

[0028] Preferably, the distance between two parallel annular surfaces of the limiting portion 13 is 1-5 mm, and the wall thickness of the flexible connecting sleeve 12 is 1-4 mm. Through experimental verification, the dimensions of the limiting portion 13 and the flexible connecting sleeve 12 within this dimension range can effectively offset the lateral stress and keep the preset position of the core body 3 unchanged.

[0029] Preferably, the material of the flexible connecting sleeve 12 is rubber or silica gel, and the hardness is 30-70 SHA.

[0030] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Without departing from the principles and purposes of the present invention, those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention, and all these changes should fall within the protection scope of the claims of the present invention.

Claims

1. A thermal stress prevention mechanism for a microchannel heat exchanger of a rail transit air conditioner, characterized in that, Comprising: At least one flexible fixing group, the flexible fixing group includes a connecting frame and a flexible connecting sleeve, the connecting frame has at least one connecting groove at one outer end of the socket core body, and the base of the connecting frame is fixed at a preset position by sleeving the outer side of the flexible connecting sleeve and fixing it with a flexible connecting sleeve flexible connecting bolt, for elastically offsetting the stress of the core body in the lateral direction.

2. The thermal stress prevention mechanism according to claim 1, characterized in that, In the thickness direction, at least part of the flexible connecting sleeve is sleeved between the bolt and the base of the connecting frame, at least part of the outer peripheral wall of the flexible connecting sleeve abuts against the inner wall of the through hole of the base of the connecting frame, and at least part of the inner peripheral wall of the flexible connecting sleeve abuts against the bolt.

3. The thermal stress prevention mechanism according to claim 2, wherein, The shape of the connecting groove is an arc surface matching the shape of the outer end of the heat exchanger, and the arc bottom end of the connecting groove is located below the center of the arc of the corresponding outer end of the heat exchanger.

4. The thermal stress prevention mechanism according to claim 2, wherein, The flexible connecting sleeve further includes a limiting part connected to the top of the flexible connecting sleeve, the outer diameter of the limiting part is larger than the outer diameter of the flexible connecting sleeve, and it is connected between the bottom of the bolt nut and the top of the base.

5. The thermal stress prevention mechanism according to claim 4, wherein, The distance between the two parallel annular surfaces of the limiting part is 1-5 mm, and the wall thickness of the flexible connecting sleeve is 1-4 mm.

6. The thermal stress prevention mechanism according to claim 1, characterized in that, The material of the flexible connecting sleeve is rubber or silica gel, and the hardness is 30-70 SHA.

7. The anti-thermal stress mechanism according to claim 1, characterized in that, It further includes a rigid sleeve connected between the bolt and the flexible connecting sleeve, and the rigid sleeve is used for rigidly supporting the inner wall of the flexible connecting sleeve.

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