Flat heat exchange tube, heat exchanger and engineering machinery

Abstract

The invention relates to a flat heat exchange tube, which is provided with planar wall parts which extend in the length and width directions of the heat exchange tube and are separated from each other in the thickness direction of the heat exchange tube, and side wall parts which stretch across the side edges of the planar wall parts and extend in the length and thickness directions of the heat exchange tube, a stress relieving part used for relieving the stress of the pipe wall is arranged in the area, close to the installation position, of at least one plane wall part of the flat heat exchange pipe, and the stress relieving part comprises one or more thin and long corrugated parts formed by locally arching or recessing the plane wall part. And the longitudinal direction of the corrugated part is basically consistent with the width direction of the heat exchange tube. The invention further relates to a heat exchanger with the flat heat exchange tube and engineering machinery with the heat exchanger.

Description

Technical Field

[0001] This invention relates to the field of heat dissipation technology, and more specifically to a flat heat exchange tube, a heat exchanger for engineering machinery, and engineering machinery having the heat exchanger. Background Technology

[0002] In construction machinery, to improve engine power and reduce fuel consumption, turbocharged air coolers are commonly used to cool the pressurized air supplied to the engine with coolant. Specific applications include engine turbocharged air coolers and compressor turbocharged air coolers. The heat exchangers in turbocharged air coolers are mostly of a tube-and-fin design, including heat exchange tube bundles and heat exchange fins. The heat exchange fins are often connected to the heat exchange tubes, and the heat exchange tubes are often connected to the end tube sheet using an expansion joint process. The heat exchange tubes and fins are often made of copper. For example, in gas engine turbocharged air coolers, due to the use of corrosive media, the heat exchanger is often made of stainless steel. This tube-plate design has the following drawbacks: 1) Low utilization rate of effective heat exchange area, with contact gaps between heat exchange elements leading to high thermal resistance and thus low heat exchange performance; 2) High material cost, complex manufacturing process, and high labor cost; 3) Difficult and costly expansion joint of stainless steel tubes; 4) Low production efficiency, unsuitable for mass production; 5) Hundreds of heat exchange tubes need to be expanded, making expansion joint quality control difficult; 6) Mechanical and thermal stresses are concentrated in the expansion joint area between the heat exchange tubes and the end tube sheet, which can easily lead to tube or tube sheet breakage and leakage.

[0003] Therefore, the present invention aims to overcome one or more of the above-mentioned problems. Summary of the Invention

[0004] To address the aforementioned problems, this invention proposes an improved flat heat exchange tube and a heat exchanger incorporating the flat heat exchange tube, which significantly improves manufacturing and assembly efficiency, enhances heat exchange efficiency, ensures product quality stability and operational reliability, reduces manufacturing and material costs, and minimizes product weight and size.

[0005] According to one aspect of the invention, a flat heat exchange tube is provided, having planar wall portions extending in the length and width directions of the heat exchange tube and spaced apart from each other in the thickness direction of the heat exchange tube, and side wall portions extending across the side edges of the planar wall portions in the length and thickness directions of the heat exchange tube. On at least one planar wall portion of the flat heat exchange tube, in a region near its installation position, a stress-reducing portion for reducing tube wall stress is provided, the stress-reducing portion including one or more elongated corrugated portions formed by partially arching or recessing the planar wall portions, the longitudinal direction of the corrugated portions being substantially aligned with the width direction of the heat exchange tube.

[0006] The corrugated feature of the flat heat exchanger tube according to the present invention can be directly formed during tube manufacturing via a stamping process. Therefore, manufacturing efficiency is high and cost is low. This corrugated feature advantageously provides stress mitigation during subsequent assembly and operation, especially in areas near the installation location of the heat exchanger tube (where high-temperature, high-pressure pressurized air enters but does not exchange heat with the coolant inside the heat exchanger tube), reducing stress concentration and ensuring product quality stability and heat exchanger operational reliability. The flat heat exchanger tube has a large contact area with the fins, which also helps reduce the thermal resistance between the heat exchanger tube and the fins, improving heat exchange efficiency. Under the same heat exchange requirements, the size and therefore weight of the heat exchanger can be designed to be smaller.

[0007] In an advantageous embodiment, a first corrugated portion is formed on the first planar wall portion of the flat heat exchange tube, and a second corrugated portion is formed on the second planar wall portion of the flat heat exchange tube opposite to the first planar wall portion. This advantageously ensures that the upper and lower planar wall portions of the flat heat exchange tube are subjected to different stresses, and the flat heat exchange tube according to the invention has better stress adaptability, thus expanding its application scenarios.

[0008] In an advantageous embodiment, the first corrugated portion protrudes along a first direction relative to the plane containing the first planar wall portion, and the second corrugated portion protrudes along a second direction relative to the plane containing the second planar wall portion, wherein the first direction is opposite to the second direction.

[0009] In an advantageous embodiment, the first and second corrugated portions are positioned opposite each other in the thickness direction of the flat heat exchange tube. This facilitates the assembly and positioning of the heat exchange tube to the tube sheet.

[0010] In an advantageous embodiment, the first and second corrugations are raised ribs that arch outwards towards the heat exchange tube. In this configuration, the cross-sectional area of ​​the fluid inside the tube is enlarged. Furthermore, the high-temperature, high-pressure air is diverted by the ribs, advantageously reducing the mechanical stress acting on the tube and tubesheet. Simultaneously, the deformation potential inherent in the rib structure itself allows for the absorption of some of the inherent mechanical stress on the tube or tubesheet, advantageously ensuring the quality of the connection between the tube and tubesheet, as well as the integrity of the seal.

[0011] In an advantageous embodiment, the flat heat exchange tube is made of stainless steel. This expands the applicability of the heat exchange tube and the heat exchanger incorporating it. Stainless steel also facilitates brazing, thus significantly improving assembly efficiency.

[0012] According to another aspect of the present invention, a heat exchanger for engineering machinery is provided, comprising: a heat exchange core, the heat exchange core including a plurality of flat heat exchange tubes and fins disposed between the flat heat exchange tubes; a first manifold box connected to one end of each flat heat exchange tube; and a second manifold box connected to the other end of each flat heat exchange tube, wherein the flat heat exchange tubes are the aforementioned flat heat exchange tubes, each flat heat exchange tube is installed to the corresponding manifold box with its open end passing through an opening formed in a fixed tube sheet fixedly connected to the corresponding manifold box and communicating with the interior of the corresponding manifold box, and a stress relief portion disposed near the installation position is located on the side of the fixed tube sheet opposite to the corresponding manifold box.

[0013] In an advantageous embodiment, the flat heat exchange tubes are fixedly connected to the fixed tube sheet in a sealed manner by brazing. Compared with the existing expansion joint process, the brazing process is more efficient and ensures both quality and reliability.

[0014] In an advantageous embodiment, the heat exchanger includes a tube sheet frame integrally or detachably connected to a manifold, with the periphery of the fixed tube sheet and the inner peripheral wall of the tube sheet frame fixedly connected in a sealed manner.

[0015] In an advantageous embodiment, the heat exchanger includes a floating tube sheet spaced apart from the fixed tube sheet on the side of the fixed tube sheet facing away from the manifold. The peripheral side of the floating tube sheet faces the inner peripheral wall of the tube sheet frame and maintains a predetermined gap with the inner peripheral wall of the tube sheet frame. Flat heat exchange tubes extend through openings in the floating tube sheet and are fixedly connected to it. The floating tube sheet facilitates the guidance or imposition of constraints on the deformation of the planar wall portion of the flat heat exchange tubes, and also absorbs some of the loads or stresses acting on the heat exchange tubes and tube sheet.

[0016] In an advantageous embodiment, at least one stress-relief section is provided between the paired floating tubesheets and the fixed tubesheet in the region near the installation location of the flat heat exchange tube. Thus, the floating tubesheets provide a layer of protection for the stress-relief section. When the dynamic or thermal load is excessive, the floating tubesheets can mitigate the impact on the stress-relief section through partial deformation, and the stress-relief section can absorb the remaining load through deformation, thereby ensuring that the load on the connection area between the tube and the tubesheet is within a controllable range. Therefore, the structure providing layered protection is more conducive to improving the operational stability and reliability of the heat exchanger.

[0017] In an advantageous embodiment, a flexible material is filled between the pairs of floating tubesheets and fixed tubesheets, and between adjacent flat heat exchange tubes, to absorb loads acting on the floating tubesheets, fixed tubesheets, or flat heat exchange tubes. Advantageously, the flexible material includes rubber or asphalt. The arrangement of the flexible filler further facilitates the absorption of most of the loads acting on or transferred from the heat exchange tubes or tubesheets, providing a buffer for the relatively rigid tubes and tubesheets, ensuring that the deformation of the tubes and tubesheets is kept as small as possible or almost zero.

[0018] In an advantageous embodiment, the stress-relief portion extends across the entire width of the flat heat exchanger tube. This ensures that the stress-relief portion is present in areas of high thermal or dynamic loads, regardless of whether the heat exchanger tube is mounted frontally or rearally. Therefore, the step of determining the installation direction of the heat exchanger tube can be eliminated during the assembly process, facilitating efficient mass production of heat exchanger tubes and heat exchangers.

[0019] According to another aspect of the present invention, an engineering machine is provided, which includes the heat exchanger described above.

[0020] Advantageously, the heat exchanger is an engine booster air cooler or a compressor booster air cooler.

[0021] The heat exchanger according to the present invention advantageously mitigates the thermal expansion of the heat exchange tubes along their length and thickness directions and enhances their structural strength in the width direction through the provision of stress-reducing portions on the heat exchange tubes. Furthermore, the floating tube sheet provides constraints on the displacement of the heat exchange tubes and the entire heat exchange core, guiding the deformation and displacement of the heat exchange tubes while simultaneously enhancing the overall strength of the heat exchange tube bundle. Additionally, the flexible filler absorbs the load transmitted between the floating tube sheet, the heat exchange tubes, and the fixed tube sheet, providing better buffering and protection for the tubes and tube sheet, as well as the connections between them. Moreover, the heat exchanger of the present invention uses flat steel heat exchange tubes, which facilitates a reduction in the size and weight of the heat exchanger product while maintaining the same performance. It also allows for direct assembly using brazing processes, improving assembly efficiency and reducing costs. Due to the aforementioned material and structural design, the heat exchanger of the present invention is suitable for completely different application scenarios, such as for turbocharged air cooling in diesel engines or turbocharged air cooling in gas engines. Attached Figure Description

[0022] The features and advantages of an example of the present invention will become apparent from the following detailed description and accompanying drawings, wherein:

[0023] Figure 1 A general schematic diagram of a heat exchanger according to the invention is shown, wherein fins are not shown in order to clearly show the layout of the flat heat exchange tubes;

[0024] Figure 2 Show Figure 1 The diagram shows a cross-section of the heat exchanger taken along line AA.

[0025] Figure 3 Show Figure 2 A magnified view of the lower right part;

[0026] Figure 4 Show Figure 3 An enlarged schematic diagram of a portion thereof; and

[0027] Figure 5 Show Figure 4 The diagram shown is a partial view of the area after the fixed tube sheet has been removed.

[0028] List of reference numerals

[0029] 1-Heat exchanger; 10-Heat exchange core; 100-Flat heat exchange tube; 11-First manifold box; 12-Second manifold box; 13-Fixed tube sheet; 14-Tube sheet frame; 101-Stress relief section; 100a-First planar wall section; 100b-Second planar wall section; 100c-Side wall section; 101a-First corrugated section; 101b-Second corrugated section; 15-Floating tube sheet; 11i-Inlet; 12o-Outlet; L-Length direction; W-Width direction; T-Thickness direction; CL-Longitudinal direction of corrugated section; AD-Air inflow direction; G-Gap. Detailed Implementation

[0030] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0031] It should be noted that the terms "comprising" and "having" and any variations thereof in the specification, claims and accompanying drawings of this invention are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such processes, methods, products or devices.

[0032] The terms "first," "second," etc., introduced in this description are for descriptive purposes only and should not be construed as indicating or implying relative importance. The directional terms "top," "bottom," "upper," "lower," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings.

[0033] See Figure 1 As shown, the heat exchanger 1 according to the present invention includes a heat exchange core 10 and manifold boxes disposed at both ends of the heat exchange core. The heat exchange core 10 includes a plurality of flat heat exchange tubes 100 arranged side by side vertically and fins (not shown) disposed between the flat heat exchange tubes. The first open end of each flat heat exchange tube 100 is connected to a first manifold box 11 for fluid communication with the internal space of the first manifold box. The second open end of each flat heat exchange tube 100 is connected to a second manifold box 12 for fluid communication with the internal space of the second manifold box.

[0034] See details Figure 2 and Figure 3 As shown, the two open ends of each flat heat exchange tube 100 pass through orifices formed on the fixed tube sheet 13 and enter the interior of the corresponding manifold box, communicating with the interior of the manifold box. The fixed tube sheet 13 is fixedly connected to the corresponding manifold box. In the illustrated embodiment, the periphery of the fixed tube sheet is fixedly connected to the inner peripheral wall of the tube sheet frame 14 in a sealed manner. The tube sheet frame 14 is detachably connected to the side of the manifold box facing the heat exchange core 10. It can be understood that the tube sheet frame can also be configured as an integral extension of the manifold box extending in the direction toward the heat exchange core. The tube sheet frame 14 is arranged to surround the end section of the heat exchange core 10. The flat heat exchange tubes 100 of the heat exchange core 10 are fixedly connected to the fixed tube sheet 13 in a sealed manner by brazing. Thus, the part of the flat heat exchange tube 100 that engages with the inner wall of the orifice on the fixed tube sheet 13 is the installation position of the flat heat exchange tube. For each flat heat exchange tube, its installation position is located in the end region where it engages with the orifice of the fixed tube sheet.

[0035] In the heat exchanger according to the invention, the flat heat exchange tube 100 is provided with a stress relief section 101 for reducing tube wall stress. The stress relief section 101 is located on the side of the fixed tube sheet 13 opposite to the corresponding manifold box.

[0036] Combination Figure 2 as well as Figures 3 to 5 As can be seen, the flat heat exchange tube 100 has planar wall portions extending in the length direction L and width direction W of the heat exchange tube and spaced apart from each other in the thickness direction T of the heat exchange tube, and side wall portions extending across the side edges of the planar wall portions in the length and thickness directions of the heat exchange tube (see...). Figure 2The diagram only shows the rear-end sidewall portion 100c located in the front-rear direction of the heat exchanger. Opposing planar wall portions and opposing sidewall portions form a pipe with a flat cavity. The flat cavity defines a channel through which working fluid flows. Working fluid from, for example, a first manifold flows through this flat cavity to a second manifold. In an embodiment of the invention, the stress-reducing portion is provided on at least one planar wall portion of the flat heat exchange tube in a region near its installation location. In the illustrated embodiment, the stress-reducing portion 101 is implemented as including one or more elongated corrugations formed by partial arching or recessing of the planar wall portions, the longitudinal direction CL of the corrugations being substantially aligned with the width direction of the heat exchange tube (see details). Figure 5 (As shown).

[0037] See Figure 4 and Figure 5 As shown, a first corrugated portion 101a is formed on the first planar wall portion 100a (upper planar wall portion) of the flat heat exchange tube 100, and a second corrugated portion 101b is formed on the second planar wall portion 100b (lower planar wall portion) of the flat heat exchange tube opposite to the first planar wall portion. The first and second corrugated portions are implemented as protrusions arching outwards from the heat exchange tube. The first corrugated portion protrudes in a first direction (upward thickness direction) relative to the plane where the first planar wall portion is located, and the second corrugated portion protrudes in a second direction (downward thickness direction) relative to the plane where the second planar wall portion is located, the first direction being opposite to the second direction. The first and second corrugated portions can be positioned opposite each other in the thickness direction of the flat heat exchange tube. Advantageously, the outer edges of the first and second corrugated portions in the length direction of the flat heat exchange tube fall in the same vertical plane, thereby facilitating the positioning and installation of the tube sheet. Therefore, from the perspective of the longitudinal section of the flat heat exchange tube, in the area near the installation position, the stress relief part 101 can provide sufficient deformable expansion to ensure that the deformation or displacement of the flat wall portion of the flat heat exchange tube due to installation stress or expansion stress occurs within a controllable range, thereby avoiding tube wall breakage and the resulting fluid leakage.

[0038] Although the first and second corrugated portions in the illustrated embodiment are shown in the form of raised strips, it can be understood that the stress relief portion can be designed as a corrugated structure with multiple peaks or troughs.

[0039] In the heat exchanger according to the present invention, a floating tube sheet 15 is provided at a distance from the fixed tube sheet 13 on the side opposite to the manifold box. The peripheral side of the floating tube sheet 15 faces the inner peripheral wall of the tube sheet frame 14 and maintains a predetermined gap G between the floating tube sheet 15 and the inner peripheral wall of the tube sheet frame 14. Flat heat exchange tubes extend through openings formed in the floating tube sheet 15 and are fixedly connected to it. Because the floating tube sheet 15 is not fixedly connected to the tube sheet frame 14, it provides certain guidance for the deformation of the flat heat exchange tubes 100 in the length, width, and thickness directions, ensuring that the deformation or displacement of the tube wall of the flat heat exchange tube is within a controllable range, constraining the displacement of individual tubes and the overall displacement of the heat exchange core, and thus absorbing some thermal stress, effectively reducing the stress or load transmitted to the fixed tube sheet. In addition, the floating tube sheet 15 and the fixed tube sheet 13 arranged in pairs in the above manner are conducive to obtaining good sealing between the tubes and the tube sheet and between the tube sheet and the tube sheet frame 14.

[0040] In the advantageous embodiment illustrated, at least one stress-relief portion 101 is provided between the paired floating tube sheet 15 and the fixed tube sheet 13 in the region near the installation location of the flat heat exchanger tube. The stress-relief portion 101 may be positioned closer to the fixed tube sheet 13 than the floating tube sheet. Thus, the stress-relief portion 101 provides stronger protection for the sealing and fixing connections at the installation location of the flat heat exchanger tube.

[0041] In the heat exchanger according to the invention, a flexible material (not shown) may be filled between the pairs of floating tube sheets 15 and fixed tube sheets 13, and between adjacent flat heat exchange tubes 100, to absorb loads acting on the floating tube sheets, fixed tube sheets, or flat heat exchange tubes. The flexible material includes, for example, rubber or asphalt, or mixtures thereof. During the operation of the heat exchanger, the loads acting on the floating tube sheets, fixed tube sheets, or flat heat exchange tubes are primarily dynamic and / or thermal loads. Excessive dynamic and / or thermal loads can lead to deformation of the heat exchange tube walls or the tube sheet, and consequently, failure of the sealing connections. Therefore, these flexible fillers can absorb excessive loads, effectively protecting the heat exchange tubes and tube sheets, and ensuring that the deformation of the tube walls and tube sheets remains within a controllable range.

[0042] According to the present invention, an engineering machine having the above-described heat exchanger is provided. This heat exchanger can be used as an engine booster air cooler or a compressor booster air cooler. In this booster air cooler, the fluid flowing through the fin gaps is high-temperature air, and the fluid flowing through the internal channels of the flat heat exchange tubes is low-temperature coolant.

[0043] In embodiments of the invention, the flat heat exchange tube 100 and the fins can be made of stainless steel. This allows for applications utilizing corrosive media (e.g., gas engines, compressors, etc.). Stainless steel also offers advantages in improving heat exchange performance, reducing material weight, and minimizing size. Furthermore, it facilitates the use of brazing processes, reducing manufacturing time.

[0044] Floating tube sheets and fixed tube sheets are made, for example, from stamped steel plates 1–3 mm thick. To ensure sufficient strength, in Figure 2-3 In the illustrated embodiment, the fixed tube sheet comprises two side-by-side steel plates. To facilitate welding, an abutment flange is provided around the periphery of the fixed tube sheet, which increases the area of ​​the contact surface with the inner peripheral wall of the tube sheet frame.

[0045] In cases where the heat exchanger of the present invention is used, for example, as a pressurized air cooler, the airflow outside the tubes experiences a high-temperature scouring section near the installation location of the heat exchange tubes. This portion of the high-temperature airflow, before heat exchange with the coolant flow inside the tubes, exerts significant dynamic and thermal loads on the connection between the tubes and the fixed tube sheet. Stress-reducing sections can be generally distributed in areas of extreme dynamic or thermal loads; that is, stress-reducing sections can be designed to extend over a portion of the width of the flat heat exchange tube. To facilitate mass production and simplify the installation process, stress-reducing sections can also be configured to extend over the entire width of the flat heat exchange tube. To improve assembly efficiency, the stress-reducing sections and / or floating tube sheets at both ends of the flat heat exchange tube can be configured to be mirror-symmetrical with respect to the central vertical cross-section of the heat exchange core.

[0046] In the embodiment shown in the attached figures, stress-reducing sections are provided at both ends of the flat heat exchange tube, and the structures of the stress-reducing sections at both ends are basically the same. A floating tube sheet is provided on the side of the stress-reducing section facing away from the fixed tube sheet. It can be understood that, depending on the specific flow channel design of the high-temperature airflow, a floating tube sheet or stress-reducing section may also be provided only at one end of the heat exchange core.

[0047] Industrial applicability

[0048] To facilitate understanding of the present invention, the installation process and working principle of the heat exchanger illustrated in the present invention will be explained below:

[0049] Multiple flat heat exchange tubes made of stainless steel are provided, with stress-reducing sections on two opposing flat wall sections at both ends of the heat exchange tubes. The heat exchange tubes are installed at predetermined intervals onto a floating tube sheet made of stainless steel (the floating tube sheet can be composed of two halves). Stainless steel fins are placed between the heat exchange tubes. After assembling the floating tube sheet, fixed tube sheets made of stainless steel are installed at both ends of the heat exchange tubes, with flexible material filled between the floating and fixed tube sheets. The fixed tube sheets are then assembled into a tube sheet frame. Welding is applied between the heat exchange tubes and fins, between the floating tube sheet and the heat exchange tubes, and between the abutment flange of the fixed tube sheet and the inner wall of the tube sheet frame. All welded parts are connected by brazing, thus obtaining the entire heat exchange core. Next, the tube sheet frames at both ends are fixedly connected to a manifold box and top and bottom side plates covering the top and bottom rows of heat exchange fins, thus obtaining the entire heat exchanger.

[0050] See Figure 1 and Figure 2 As shown, the pressurized airflow to be cooled enters the heat exchanger along the airflow direction AD. The coolant enters the manifold box from the inlet 11i of the first manifold box 11, and is distributed into each flat heat exchange tube. When flowing through the heat exchange tube, it exchanges heat with the airflow outside the tube. Then, the coolant enters the second manifold box 12 and is discharged from the outlet 12o of the second manifold box.

[0051] Therefore, in the tube-to-tubesheet connection area, the part closest to the incoming pressurized air experiences the largest thermal and dynamic loads. Thanks to the stress-relief section, the floating tubesheet, and the flexible packing, the load ultimately transmitted to the connection between the tube and the fixed tubesheet is significantly reduced, thereby ensuring the integrity of the heat exchange tubes and the strength and sealing of the connection between the tubes and the fixed tubesheet.

[0052] The above description is merely of exemplary embodiments according to the present invention. The method and apparatus are not limited to the specific embodiments described herein. Throughout this specification, references to “an example,” “another example,” “example,” etc., mean that a certain element / component (e.g., feature, structure, and / or characteristic) associated with an example is included in at least one example described herein, and may appear and / or may not appear in other examples. Furthermore, it is understood that multiple elements of any example described may be combined in any suitable manner in multiple different examples unless the context clearly indicates otherwise.

[0053] This specification uses examples to disclose the invention, including preferred embodiments, and enables any person skilled in the art to implement the invention. The patentable scope of the invention is defined by the claims, but may include other examples that may be conceived by a person skilled in the art. Such other examples should fall within the scope of the claims if they have structural elements that are not distinct from the literal language of the claims, or if they include equivalent structural elements that are not substantially distinct from the literal language of the claims.

Claims

1. A flat heat exchange tube, comprising planar wall portions extending in the length and width directions of the heat exchange tube and spaced apart from each other in the thickness direction of the heat exchange tube, and side wall portions extending across the planar wall portions in the length and thickness directions of the heat exchange tube, wherein, On at least one planar wall portion of the flat heat exchange tube, in a region near its installation location, a stress-reducing section is provided for mitigating tube wall stress. The stress-reducing section includes one or more elongated corrugated portions formed by partial arching or recessing of the planar wall portion, the longitudinal direction of which is substantially aligned with the width direction of the heat exchange tube.

2. The flat heat exchange tube according to claim 1, characterized in that, A first corrugated portion is formed on the first planar wall portion of the flat heat exchange tube, and a second corrugated portion is formed on the second planar wall portion of the flat heat exchange tube opposite to the first planar wall portion.

3. The flat heat exchange tube according to claim 2, characterized in that, The first corrugated portion protrudes along a first direction relative to the plane containing the first planar wall portion, and the second corrugated portion protrudes along a second direction relative to the plane containing the second planar wall portion, with the first direction being opposite to the second direction.

4. The flat heat exchange tube according to claim 3, characterized in that, The first and second corrugated sections are positioned opposite each other in the thickness direction of the flat heat exchange tube.

5. The flat heat exchange tube according to claim 4, characterized in that, The first and second corrugated sections are raised ridges that arch outwards towards the outside of the heat exchange tube.

6. The flat heat exchange tube according to any one of claims 1-5, characterized in that, The flat heat exchange tubes are made of stainless steel.

7. A heat exchanger for engineering machinery, comprising: Heat exchanger core, The heat exchange core includes multiple flat heat exchange tubes and fins disposed between the flat heat exchange tubes; The first manifold box is connected to one end of each flat heat exchange tube; And a second manifold box connected to the other end of each flat heat exchange tube, wherein the flat heat exchange tube is a flat heat exchange tube according to any one of claims 1-6, each flat heat exchange tube is installed to the corresponding manifold box with its open end passing through an opening formed on a fixed tube sheet fixedly connected to the corresponding manifold box and communicating with the interior of the corresponding manifold box, and the stress relief part provided near the installation position is located on the side of the fixed tube sheet opposite to the corresponding manifold box.

8. The heat exchanger according to claim 7, characterized in that, Each flat heat exchange tube is fixedly connected to the fixed tube sheet by brazing in a sealed manner.

9. The heat exchanger according to claim 8, characterized in that, The heat exchanger includes a tube sheet frame integrally or detachably connected to a manifold, with the periphery of the fixed tube sheet and the inner peripheral wall of the tube sheet frame fixedly connected in a sealed manner.

10. The heat exchanger according to claim 9, characterized in that, The heat exchanger includes a floating tube sheet spaced apart from the fixed tube sheet on the side of the fixed tube sheet away from the manifold. The peripheral side of the floating tube sheet faces the inner peripheral wall of the tube sheet frame and maintains a predetermined gap with the inner peripheral wall of the tube sheet frame. Flat heat exchange tubes extend through the openings of the floating tube sheet and are fixedly connected to it.

11. The heat exchanger according to claim 10, characterized in that, In the region near the installation location of the flat heat exchange tube, at least one stress-relief section is provided between the paired floating tube sheet and the fixed tube sheet.

12. The heat exchanger according to claim 11, characterized in that, Flexible material is filled between pairs of floating tube sheets and fixed tube sheets, and between adjacent flat heat exchange tubes, to absorb the loads acting on the floating tube sheets, fixed tube sheets, or flat heat exchange tubes.

13. The heat exchanger according to claim 12, characterized in that, The flexible material includes rubber or asphalt.

14. The heat exchanger according to any one of claims 7-13, characterized in that, The stress-relief section extends across the entire width of the flat heat exchange tube.

15. An engineering machine comprising a heat exchanger according to any one of claims 7-14.

16. The engineering machinery according to claim 15, characterized in that, The heat exchanger is an engine booster air cooler or a compressor booster air cooler.

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