A heat exchange tube anti-damage structure applied to a jet impact environment

Abstract

The application relates to a heat exchange pipe anti-damage structure applied to a jet flow impact environment, and relates to a heat exchange pipe anti-damage structure. In order to solve the problem that high-speed jet flow generates impact force on a heat exchange pipe, stress deformation and fatigue damage of the heat exchange pipe in the prior art, the application comprises a flow shedding column and a rectangular venturi pipe, the flow shedding column is provided with a through hole, a heat exchange pipe is arranged in the through hole, the rectangular venturi pipe can slide relative to the flow shedding column, the cross section of the flow shedding column is oval, when jet flow passes through the flow shedding column, the maximum pressure on the flow-approaching side of the flow shedding column is reduced, and the minimum pressure on the flow-receding side is increased, the pressure difference between the flow-approaching side and the flow-receding side can be effectively reduced, the impact force on the flow shedding column is reduced, and fatigue damage of the heat exchange pipe is reduced; meanwhile, the increase of the minimum pressure can prevent the occurrence of cavitation. The application belongs to the technical field of heat exchange pipe protection.

Description

Technical Field

[0001] This invention relates to a heat exchanger tube damage prevention structure, specifically a heat exchanger tube damage prevention structure applied in a jet impact environment, belonging to the field of heat exchanger tube protection technology. Background Technology

[0002] Some equipment commonly generates heat during operation, especially high-power equipment such as internal combustion engines, motors, and boilers. Cooling systems or heat exchange equipment are required to reduce the temperature and ensure safe operation of the equipment.

[0003] In the design of cooling systems or heat exchange equipment, in order to reduce the overall size of the equipment, the heat exchange medium is usually flowed through the tube bundle in a high-speed jet manner, thereby increasing the heat exchange efficiency.

[0004] However, the high-speed jet inevitably exerts an impact force on the heat exchange tube, causing stress deformation. At the same time, the fixed-frequency vibration generated during the flow of the heat exchange medium will also increase fatigue damage to the heat exchange tube, thereby increasing cavitation and accelerating corrosion.

[0005] In summary, how to propose a damage-resistant structure for heat exchange tubes to address the aforementioned technical problems has become a pressing issue for those skilled in the art. Summary of the Invention

[0006] To address the shortcomings of the prior art, this invention provides a heat exchange tube anti-damage structure applicable to jet impact environments.

[0007] The technical solution of the present invention is: a heat exchange tube anti-damage structure applied in jet impact environment, including a flow separation column and a rectangular venturi tube.

[0008] The cross-section of the de-flow column is oval. The de-flow column has a through hole and two insertion holes. The axis of the through hole is parallel to the axis of the de-flow column, and the heat exchange tube is inserted into the through hole.

[0009] The axis of the rectangular venturi tube is perpendicular to the axis of the heat exchange tube, and the larger end of the rectangular venturi tube opening faces the heat exchange tube.

[0010] The rectangular venturi tube is a rectangular tube body welded together with a lower inclined plate, an upper inclined plate and two side plates; the angle between the upper and lower inclined plates and the horizontal plane is β, and the angle between the upper and lower inclined plates is 2β; both side plates are arranged perpendicular to the horizontal plane, the length of the side plates is greater than the height of the de-flow column, and the side plates are inserted into the insertion holes.

[0011] Furthermore, the height of the de-flow column is H, and the length of the heat exchange tube is L, where L = (10~20)·H.

[0012] Furthermore, the outer contour of the de-flow column cross-section includes a semi-elliptical segment and a semi-circular segment. The semi-elliptical segment and the semi-circular segment are tangent, with the semi-circular segment on the upstream side and the semi-elliptical segment on the downstream side. The minor axis radius of the semi-elliptical segment is a, the major axis radius of the semi-elliptical segment is b, and the radius of the semi-circular segment is R, where a = R, H = (2~3)·b, and b = (2~3)·R.

[0013] Compared with the prior art, the present invention has the following advantages:

[0014] The cross-section of the de-flow column 2 of this invention is oval. When the jet flows through the de-flow column 2, the maximum pressure on the front side of the de-flow column 2 decreases, and the minimum pressure on the back side increases. This change can effectively reduce the pressure difference between the front and back sides, reduce the impact force on the de-flow column 2, and reduce fatigue damage to the heat exchange tube 1. At the same time, the increase in minimum pressure can prevent cavitation.

[0015] The de-fluidization column 2 can slide on the heat exchange tube 1. During the sliding process, it can interrupt the vibration at various positions on the heat exchange tube 1 at any time, thereby generating a disturbance effect, thus avoiding stress concentration on the heat exchange tube 1 and further reducing its fatigue loss. Attached Figure Description

[0016] Figure 1 This is an isometric sectional view of the present invention;

[0017] Figure 2 This is an isometric sectional view of the dewatering column 2 of the present invention;

[0018] Figure 3 This is an isometric view of the rectangular venturi tube 2-2 of the present invention;

[0019] Figure 4 This is a cross-sectional view of the rectangular venturi tube 2-2 of the present invention;

[0020] Figure 5 This is a top view of the dewatering column 2 of the present invention;

[0021] Figure 6 This is a schematic diagram of the invention installed on a heat exchange tube;

[0022] Figure 7 This is a schematic diagram of the rectangular venturi tube 2-2 of the present invention sliding on the dewatering column 2;

[0023] Figure 8 This is a velocity distribution cloud map of the high-speed jet directly impacting the heat exchange tube 1 when the present invention is not used. The transition from blue to red in the cloud map indicates that the velocity of the high-speed jet is increasing.

[0024] Figure 9This is a pressure distribution diagram of the high-speed jet directly impacting the heat exchange tube 1 when the present invention is not used. The transition from blue to red on the line indicates that the pressure of the high-speed jet is increasing.

[0025] Figure 10 This is a graph showing the change in the impact force of the high-speed jet over time when the heat exchanger tube 1 is not using this invention.

[0026] Figure 11 This is a velocity distribution cloud map of the high-speed jet impacting the de-fluidization column 2 when the heat exchange tube 1 uses the present invention. The transition from blue to red in the cloud map indicates that the velocity of the high-speed jet is increasing.

[0027] Figure 12 This is a pressure distribution diagram of the high-speed jet impacting the de-flow column 2 when the heat exchange tube 1 uses the present invention. The transition from blue to red on the line indicates that the pressure of the high-speed jet is increasing.

[0028] Figure 13 This is a graph showing the change in the impact force of the high-speed jet over time when the heat exchanger tube 1 uses the present invention.

[0029] In the diagram: 1. Heat exchange tube; 2. Flow separation column; 2-2. Rectangular Venturi tube; 2-2-1. Side plate; 2-2-2. Upper inclined plate; 2-2-3. Lower inclined plate; 2-3. Low friction sleeve; 3. Lower heat exchanger; 4. Upper heat exchanger. Detailed Implementation

[0030] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments.

[0031] Specific implementation method one: Combining Figures 1 to 7 This embodiment describes a heat exchange tube damage prevention structure applied in a jet impact environment, which includes a flow-depleting column 2 and a rectangular venturi tube 2-2.

[0032] The cross-section of the de-flow column 2 is oval. The de-flow column 2 has a through hole and two insertion holes. The axis of the through hole is parallel to the axis of the de-flow column 2. The heat exchange tube 1 is inserted into the through hole. The axis of the rectangular venturi tube 2-2 is perpendicular to the axis of the heat exchange tube 1, and the larger end of the opening of the rectangular venturi tube 2-2 faces the heat exchange tube 1.

[0033] The rectangular venturi tube 2-2 is a rectangular tube body welded together from the lower inclined plate 2-2-3, the upper inclined plate 2-2-2, and two side plates 2-2-1; the included angles between the upper inclined plate 2-2-2 and the lower inclined plate 2-2-3 and the horizontal plane are both β, and the included angle between the upper inclined plate 2-2-2 and the lower inclined plate 2-2-3 is 2β.

[0034] Both side plates 2-2-1 are arranged perpendicular to the horizontal plane. The length of the side plate 2-2-1 is greater than the height of the dewatering column 2. The side plate 2-2-1 is inserted into the socket. With this arrangement, the side plate 2-2-1 can slide in the socket so that the rectangular venturi tube 2-2 and the dewatering column 2 can slide relative to each other.

[0035] In this embodiment, both side plates 2-2-1 are isosceles trapezoidal side plates, and the length of the short base of the isosceles trapezoid is greater than the height of the dewatering column 2.

[0036] Specific Implementation Method Two: Combining Figure 2 and Figure 5 In this embodiment, the height of the de-flow column 2 is H, the length of the heat exchange tube 1 is L, and L = (10~20)·H.

[0037] Furthermore, the outer contour of the cross-section of the de-flow column 2 includes a semi-elliptical segment and a semi-circular segment. The center of the through hole coincides with the center of the semi-circular segment. The semi-elliptical segment is tangent to the semi-circular segment, and the semi-circular segment is on the front side of the flow, while the semi-elliptical segment is on the back side of the flow.

[0038] The minor axis radius of the semi-elliptical segment is a, the major axis radius of the semi-elliptical segment is b, and the radius of the semicircle segment is R, and a=R, H=(2~3)·b, b=(2~3)·R.

[0039] The other components and connections are the same as in Specific Implementation Method 1.

[0040] Specific implementation method three: Combining Figure 2 , Figure 3 and Figure 4 In this embodiment, the upper surface of the dewatering column 2 has an upper groove with a right-angled triangular cross-section. The inclined surface of the upper groove is parallel to the upper inclined plate 2-2-2. This arrangement facilitates the upper inclined plate 2-2-2 to abut against the inclined surface of the upper groove.

[0041] Furthermore, the lower surface of the dewatering column 2 has a groove with a right-angled triangular cross-section. The inclined surface of the groove is parallel to the lower inclined plate 2-2-3. This arrangement facilitates the lower inclined plate 2-2-3 to abut against the inclined surface of the groove.

[0042] The other components and connections are the same as in specific implementation method one or two.

[0043] Specific implementation method four: Combination Figure 1 This embodiment further includes a low-friction sleeve 2-3. The outer circumferential surface of the low-friction sleeve 2-3 is fixedly connected to the inner circumferential surface of the through hole, and the inner circumferential surface of the low-friction sleeve 2-3 is slidably connected to the outer circumferential surface of the heat exchange tube 1. This arrangement reduces the friction between the de-fluidization column 2 and the heat exchange tube 1.

[0044] The other components and connections are the same as those in specific implementation methods one, two, or three.

[0045] Specific Implementation Method Five: Combining Figure 1 and Figure 3 In this embodiment, the low-friction sleeve 2-3 is made of polytetrafluoroethylene.

[0046] Furthermore, the lower inclined plate 2-2-3, the upper inclined plate 2-2-2, and the two side plates 2-2-1 are all made of stainless steel.

[0047] The other components and connections are the same as those in specific implementation methods one, two, three, or four.

[0048] Example

[0049] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings:

[0050] Example 1:

[0051] Combination Figures 8 to 10 In this embodiment, when the cooling system or heat exchange equipment is working, the heat exchange medium flows through the heat exchange tube in the form of a high-speed jet. When the jet impacts the heat exchange tube 1, a Karman vortex street often forms downstream of the heat exchange tube 1. The flow velocity of the jet also changes after impacting the heat exchange tube 1. This is analyzed and explained using COMSOL Multiphysics simulation software. Before the simulation calculation, a flow field is established in the software. The jet inlet is defined upstream of the heat exchange tube 1, and the jet outlet is defined downstream of the heat exchange tube 1.

[0052] like Figure 8 As shown, when the present invention is not installed on heat exchange tube 1, the high-speed jet directly impacts heat exchange tube 1. When the jet velocity is 3 m / s, a Karman vortex street appears downstream of heat exchange tube 1, such as... Figure 9 As shown, the flow-facing side of heat exchanger tube 1 experiences higher pressure, while the flow-reverse side exhibits negative pressure (the static pressure at the jet outlet is 0). This pressure difference between the flow-facing and flow-reverse sides creates an impact force on heat exchanger tube 1, and the negative pressure easily leads to cavitation. Figure 10 As shown, by integrating the force on the outer circumference of heat exchange tube 1 along the jet flow direction in the simulation software, the trend of the impact force changing with time can be obtained. It can be seen that the force on heat exchange tube 1 exhibits periodic changes, and this periodic force causes fatigue damage to heat exchange tube 1.

[0053] Example 2:

[0054] Combination Figures 11 to 13 This embodiment is described as follows: Figure 11As shown, when the present invention is installed on heat exchange tube 1, the high-speed jet simultaneously impacts heat exchange tube 1 and flow separation column 2. While ensuring the flow characteristics remain unchanged and the jet velocity is still 3 m / s, the comparison... Figure 8 and Figure 11 As can be seen, although a Karman vortex street still exists downstream of the separation column 2, the pressure drop on the upstream and downstream sides of the separation column 2 changes significantly. Figure 9 and Figure 12 As can be seen, the maximum pressure on the upstream side of the de-current column 2 decreases, while the minimum pressure on the downstream side increases. This change can effectively reduce the pressure difference between the upstream and downstream sides and reduce the impact force on the de-current column 2.

[0055] At the same time, increasing the minimum pressure can prevent cavitation from occurring. For example... Figure 13 As shown, by integrating the force on the outer circumference of the de-fluidizing column 2 along the jet flow direction, it can be seen that the fluctuation amplitude and fluctuation frequency of the impact force are reduced, which is beneficial to reducing the fatigue damage of the heat exchange tube 1.

[0056] Working principle

[0057] Combination Figures 1 to 7 Explanation of the working principle of this invention:

[0058] The two ends of the heat exchange tube 1 are fixedly connected to the lower heat exchanger 3 and the upper heat exchanger 4 on the cooling system or heat exchange equipment, respectively. The heat exchange tube 1 is inserted into the through hole of the de-flow column 2. The cross-section of the de-flow column 2 is oval, and the large end of the opening of the rectangular venturi tube 2-2 faces the heat exchange tube 1.

[0059] When the jet flows through the de-flow column 2, the maximum pressure on the front side of the de-flow column 2 decreases, while the minimum pressure on the back side increases. This change can effectively reduce the pressure difference between the front and back sides, reduce the impact force on the de-flow column 2, and reduce fatigue damage to the heat exchange tube 1.

[0060] Since the length of the side plate 2-2-1 in the rectangular venturi tube 2-2 is greater than the height of the dewatering column 2, the rectangular venturi tube 2-2 and the dewatering column 2 can slide relative to each other. When the jet flows through the area between the lower surface of the upper inclined plate 2-2-2 and the upper surface of the dewatering column 2, the jet velocity in this area increases, generating an upward force that pushes the upper inclined plate 2-2-2. At the same time, the lower inclined plate 2-2-3 abuts against the inclined surface of the lower groove, thereby applying an upward force to the entire dewatering column 2, pushing the dewatering column 2 to move upward along the heat exchange tube 1.

[0061] When the de-flow column 2 approaches the top of the heat exchange tube 1, the upper inclined plate 2-2-2 first collides with the upper heat exchange element 4, and then the rectangular venturi tube 2-2 stops moving. The de-flow column 2 will continue to move upward due to inertia until the lower surface of the upper inclined plate 2-2-2 abuts against the inclined surface of the upper groove. At the same time, the upper surface of the lower inclined plate 2-2-3 separates from the lower surface of the de-flow column 2. The jet flows through the area between the upper surface of the lower inclined plate 2-2-3 and the lower surface of the de-flow column 2, and then generates a downward force to push the lower inclined plate 2-2-3, pushing the de-flow column 2 to move downward along the heat exchange tube 1. This process is repeated to realize the de-flow column 2 moving back and forth on the heat exchange tube 1.

[0062] Similarly, multiple de-flow columns 2 can be installed on a heat exchange tube 1. The movement pattern of each de-flow column 2 is generated randomly by itself. That is, during the collision between two de-flow columns 2, their respective commutation effects can also be achieved. When the weak point of the heat exchange tube 1 is known (for example, there is obvious deformation or corrosion on the circumference of the heat exchange tube 1), and protection is required for a specific location, the rectangular Venturi tube 2-2 on the de-flow column 2 can be removed, and the de-flow column 2 can be fixed to the location that needs protection.

[0063] The present invention has been disclosed above with reference to preferred embodiments, but it is not intended to limit the present invention. Any simple modifications, equivalent changes and alterations made by those skilled in the art to the above embodiments without departing from the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A heat exchange tube damage prevention structure applied in jet impact environments, characterized in that: It includes a de-flow column (2) and a rectangular venturi tube (2-2); The cross-section of the dewatering column (2) is oval. The dewatering column (2) has a through hole and two insertion holes. The axis of the through hole is parallel to the axis of the dewatering column (2). The heat exchange tube (1) is inserted into the through hole. The axis of the rectangular venturi tube (2-2) is perpendicular to the axis of the heat exchange tube (1), and the large end of the opening of the rectangular venturi tube (2-2) faces the heat exchange tube (1). The rectangular venturi tube (2-2) is a rectangular tube body welded together from a lower inclined plate (2-2-3), an upper inclined plate (2-2-2), and two side plates (2-2-1); the included angles between the upper inclined plate (2-2-2) and the lower inclined plate (2-2-3) and the horizontal plane are both... β And the included angle between the upper inclined plate (2-2-2) and the lower inclined plate (2-2-3) is 2. β Both side plates (2-2-1) are arranged perpendicular to the horizontal plane. The length of the side plate (2-2-1) is greater than the height of the dewatering column (2). The side plate (2-2-1) is inserted into the socket. The upper surface of the de-flow column (2) has an upper groove with a right-angled triangle cross-section, and the inclined surface of the upper groove is parallel to the upper inclined plate (2-2-2); the lower surface of the de-flow column (2) has a lower groove with a right-angled triangle cross-section, and the inclined surface of the lower groove is parallel to the lower inclined plate (2-2-3).

2. The heat exchange tube anti-damage structure applied in a jet impact environment according to claim 1, characterized in that: The height of the de-flow column (2) is H, and the length of the heat exchange tube (1) is L, where L = (10~20)·H.

3. The heat exchange tube anti-damage structure applied in a jet impact environment according to claim 2, characterized in that: The outer contour of the cross-section of the de-flow column (2) includes a semi-elliptical segment and a semi-circular segment. The semi-elliptical segment and the semi-circular segment are tangent, and the semi-circular segment is the front side and the semi-elliptical segment is the back side. The minor axis radius of the semielliptic segment is a The major axis radius of the semi-elliptic segment is b The radius of the semicircle is R ,and a = R H = (2~3)· b , b =(2~3)· R .

4. The heat exchanger tube damage prevention structure applied in a jet impact environment according to claim 1, characterized in that: It also includes a low-friction sleeve (2-3), the outer circumferential surface of the low-friction sleeve (2-3) is fixedly connected to the inner circumferential surface of the through hole, and the inner circumferential surface of the low-friction sleeve (2-3) is slidably connected to the outer circumferential surface of the heat exchange tube (1).

5. The heat exchange tube anti-damage structure applied in a jet impact environment according to claim 4, characterized in that: The low-friction sleeve (2-3) is made of polytetrafluoroethylene.

6. The heat exchanger tube damage prevention structure applied in a jet impact environment according to claim 1, characterized in that: The lower inclined plate (2-2-3), the upper inclined plate (2-2-2), and the two side plates (2-2-1) are all made of stainless steel.

Images