Triangular jet heat exchange tube and heat exchanger

Abstract

The invention provides a triangular jet heat exchange tube and a heat exchanger, according to the triangular jet heat exchange tube, the cross section of the heat exchange tube is triangular, a regular triangle is formed between connecting lines of adjacent vertexes of the triangle, a tube wall is formed between the adjacent vertexes, the tube wall is in an arc shape, and the bending direction of the arc faces the interior of the regular triangle. And spraying holes for spraying from the inside of the heat exchange tube to the outside of the heat exchange tube are formed in the tube wall. The invention provides a novel heat exchange tube structure and a novel layout mode, so that the heat exchange area is enlarged, two fluids are mixed more uniformly, and the heat exchange efficiency is improved.

Description

Technical Field

[0001] This invention relates to a heat exchanger for direct mixing of two fluids, and more particularly to a shell-and-tube heat exchanger for vapor-liquid mixing heat exchange. Background Technology

[0002] Shell-and-tube heat exchangers are widely used in industries such as chemical, petroleum, refrigeration, nuclear power, and energy. Due to the global energy crisis, the demand for heat exchangers in industrial production is increasing, and the quality requirements for heat exchangers are also becoming more stringent. In recent decades, although compact heat exchangers (plate, plate-fin, and welded plate heat exchangers, etc.), heat pipe heat exchangers, and direct contact heat exchangers have developed rapidly, shell-and-tube heat exchangers still dominate in terms of production and usage due to their high reliability and wide adaptability. According to relevant statistics, shell-and-tube heat exchangers still account for about 70% of all heat exchangers used in industrial plants.

[0003] Currently, people usually use heat exchangers to heat water. In various shell-and-tube and plate heat exchangers, the two fluids flow through different channels and exchange heat through good conductors. The water flow channels are generally designed to be winding and tortuous to increase the contact area with steam and enable it to be fully heated. As a result, there are defects such as complex structure, slow heating speed, high vibration and noise, and low thermal efficiency. Although the noise can be reduced to some extent by installing silencers, the flow rate and velocity of steam must be limited, and the shortcomings of slow heating speed and low thermal efficiency still exist.

[0004] Existing technologies also include some inventions related to direct mixing and heat exchange of two fluids. For example, CN101705107A discloses a jet cooler, including a Venturi jet tube and a cyclone separator. The cyclone separator's mixing inlet is connected to the Venturi jet tube, and the pyrolysis gas inlet is located in the diffuser section of the Venturi jet tube at a 30-50 degree angle to its axis. A wire mesh, an airflow barrier cone, and an oil tank are added. The stacked wire mesh is installed inside the cyclone separator's outlet pipe, and an airflow barrier cone is suspended at the bottom of the outlet pipe. The liquid outlet at the bottom of the cyclone separator is inserted into the liquid in the oil tank. The cold bio-oil sprayed from the Venturi jet tube mixes with the pyrolysis gas to form a high-speed fluid carrying the pyrolysis gas. This fluid enters the cyclone separator horizontally and tangentially through the mixing inlet, rotating and mixing for heat exchange, thereby achieving rapid heat exchange, cooling, and liquefaction of the liquefiable gas. CN102636061A discloses a hybrid heat exchange and energy storage shell-and-tube evaporator, which is mainly used for the efficient evaporation of working fluids, and is particularly suitable for situations with fluctuating heat sources and low heat transfer coefficients. This hybrid heat exchange and energy storage shell-and-tube evaporator includes a shell and heat exchange tubes. Its main feature is that a liquid heat storage medium is injected between the heat exchange tubes, and a gas-liquid separation space is set above the heat storage medium. One or more guide tubes are set in the liquid heat storage medium, and one or more guide tube outlets are distributed on each guide tube. The high-temperature fluid first indirectly heats the heat storage medium through the heat exchange tubes, and the heat storage medium and the low-temperature fluid directly mix and contact to achieve heat exchange and evaporation. Since the liquid heat storage medium can play the role of heat storage and heat transfer, it solves the problem of system instability caused by heat source fluctuations, and also improves the heat transfer coefficient and thermal utilization rate of the system. This evaporator has the advantages of simple structure, high thermal efficiency, low cost, and strong applicability. CN119958313A discloses a shell-and-tube heat exchanger for vapor-liquid mixing and heat exchange, and a heat exchange method thereof. The shell-and-tube heat exchanger includes a shell, heat exchange tubes, a liquid inlet pipe, an inlet end cap, and an outlet end cap. A first end and a second end of the heat exchange tubes are fixedly connected to an inlet tube sheet and an outlet tube sheet, respectively. The first end is connected to the inlet end cap, while the second end is not connected to the outlet end cap. Vapor outlet holes are provided on the tube walls of the heat exchange tubes, and through holes are provided on the outlet tube sheet connecting the shell and the outlet end cap. The shell-and-tube heat exchanger is a horizontal type. Multiple through holes are provided, with the density increasing from bottom to top. This invention provides a shell-and-tube heat exchanger for direct vapor-liquid mixing. By varying the density of through holes in the vertical direction, the vapor-liquid heat exchange effect can be improved.

[0005] In existing technologies, heat exchange involving the mixing of two fluids presents several problems, such as a single heat exchange tube, a small heat exchange area for mixing steam and liquid, and uneven mixing of the two fluids. This application adopts a novel structure and layout of the heat exchange tube, which expands the heat exchange area, increases the mixing zone, and makes the mixing of the two fluids more uniform. Summary of the Invention

[0006] In order to overcome the defects and deficiencies in the existing technology, the present invention provides a shell-and-tube heat exchanger for vapor-liquid mixing and heat exchange, and the heat exchange method thereof, which can increase the heat exchange area, increase the mixing zone, and make the two fluids mix more uniformly, thereby effectively improving the heat transfer efficiency.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows: A triangular jet heat exchanger tube has a triangular cross-section. The lines connecting adjacent vertices of the triangle form an equilateral triangle, and a tube wall is formed between adjacent vertices. The tube wall is arc-shaped, and the curvature of the arc faces the inside of the equilateral triangle. Jet holes are formed on the tube wall to spray from the inside of the heat exchanger tube to the outside.

[0008] As an improvement, the three arcs of the heat exchange tube have the same diameter and the same curvature.

[0009] As an improvement, the extension line of the injection direction of the injection hole is directed toward the inner center of the equilateral triangle.

[0010] As an improvement, the arc's radius is 20-70°.

[0011] As an improvement, the arc's radius is 40-50°.

[0012] A heat exchanger includes a shell, heat exchange tubes, a liquid inlet pipe, an inlet end cap, and an outlet end cap. A first fluid inlet pipe is disposed on the shell, and a second fluid inlet pipe and a mixed fluid outlet pipe are respectively disposed on the inlet end cap and the outlet end cap. An inlet tube sheet is disposed between the inlet end cap and the shell, and an outlet tube sheet is disposed between the outlet end cap and the shell. The heat exchange tubes are disposed in the shell, and a first end and a second end of the heat exchange tubes are respectively fixedly connected to the inlet tube sheet and the outlet tube sheet, wherein the first end communicates with the inlet end cap, and the second end is not communicated with the outlet end cap. The outlet tube sheet has a through hole communicating with the shell and the outlet end cap. The heat exchange tubes are the aforementioned heat exchange tubes.

[0013] As an improvement, the heat exchange tubes are arranged in a triangular pattern, with the centers of the arcs between three adjacent heat exchange tubes at a single point.

[0014] As an improvement, the shell-and-tube heat exchanger is a horizontal shell-and-tube heat exchanger. The distribution density of the injection holes of different heat exchange tubes is different. Along the height direction from bottom to top, the distribution density of the injection holes of different heat exchange tubes increases.

[0015] As an improvement, the distribution density of the injection holes of different heat exchange tubes increases progressively along the upward height direction.

[0016] As an improvement, the second fluid is steam, and the first fluid is liquid.

[0017] Compared with the prior art, the present invention has the following advantages: 1. This invention improves the triangular tube into an inwardly curved arc shape, increasing the heat exchange area. Moreover, because of the inwardly curved arc, the fluid inside the tube flows more from the center of the tube to the apex, thereby increasing the pressure at the corner. Compared with other shapes, this reduces the flow dead zone and avoids uneven spraying caused by uneven fluid distribution at different locations, thus making the overall sprayed fluid uniform.

[0018] 2. This application improves the triangular tube by making it an inwardly curved arc shape, which increases the flow area of ​​the external fluid and the mixing area and mixing time of the two fluids, thereby making the mixing more uniform and the heat exchange effect better.

[0019] 3. This application improves the mixing effect and heat exchange efficiency by using a triangular distribution of heat exchange tubes within the heat exchanger, combined with the corresponding triangular shape of the heat exchange tubes, and ensuring that the centers of the arcs between three adjacent heat exchange tubes are at the same point. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the cross-sectional structure of the triangular jet heat exchanger tube of the present invention; Figure 2 This is a three-dimensional schematic diagram of the triangular jet heat exchanger tube of the present invention; Figure 3 This is a schematic diagram of the triangular jet heat exchanger tube of the present invention. Figure 1 ; Figure 4 This is a schematic diagram of the triangular jet heat exchanger tube of the present invention. Figure 2 ; Figure 5 This is a schematic diagram of the triangular jet heat exchanger tube of the present invention. Figure 3 ; Figure 6 This is a schematic diagram of the heat exchanger structure of the heat exchanger of the present invention; Figure 7 This is a schematic diagram of the heat exchange tube arrangement of the heat exchanger of the present invention; Figure 8 This is a partial schematic diagram of the heat exchange tube arrangement of the heat exchanger of the present invention. Detailed Implementation

[0021] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0022] Unless otherwise specified, in this article, " / " represents division, and "×" and "*" represent multiplication when formulas are involved.

[0023] Figure 1-8The triangular jet heat exchanger tube and heat exchanger of the present invention are shown. For example... Figure 1-5 As shown, a triangular jet heat exchanger tube 1 has a triangular cross-section. The lines connecting adjacent vertices 11 of the triangle form an equilateral triangle, and the adjacent vertices form a tube wall 12. Figure 1 As shown, the tube wall 12 is arc-shaped, and the curvature of the arc faces the inside of the equilateral triangle. The tube wall 12 has injection holes 13 that spray from the inside of the heat exchange tube to the outside.

[0024] This invention increases the heat exchange area by modifying the triangular tube into an inwardly curved arc shape. Moreover, because of the inwardly curved arc, the fluid inside the tube flows more from the center to the apex of the tube, thereby increasing the pressure at the corner. Compared with other shapes, this reduces the flow dead zone and avoids uneven spraying caused by uneven fluid distribution at different locations, thus making the overall sprayed fluid uniform.

[0025] As an improvement, the three arcs of the heat exchange tube have the same diameter and the same curvature. This arrangement ensures that the circumferential spray volume is uniform.

[0026] As an improvement, the extension line of the spray direction of the spray orifice is oriented towards the center of the equilateral triangle. This arrangement ensures more uniform spraying from the center of the spray tube outwards, including better heat exchange with the fluid outside the tube.

[0027] As an improvement, the arc angle is 20-70°. Alternatively, the arc angle is 40-50°. These angles are the optimal values ​​derived from extensive numerical simulations and experimental studies. These angles ensure the most uniform mixing and heat exchange between the two fluids inside and outside the tube, achieving the best heat exchange effect.

[0028] As an improvement, such as Figure 6 As shown, the vertex position is set as an arc, which curves outward. Injection holes are provided on the arc. By setting the vertex as an outward-curving arc, the internal fluid flow can be more evenly distributed. Furthermore, by setting the injection holes at fixed points, the injection direction can be distributed around the perimeter of the pipe, resulting in a more uniform distribution of the injected fluid and achieving better heat exchange.

[0029] As an improvement, the extension line of the jet direction of the jet orifice of the vertex arc passes through the center of the equilateral triangle. As an improvement, the center of the arc is located at the center of the equilateral triangle. With the above arrangement, the distribution of the jet fluid can be further made more uniform.

[0030] As an improvement, the radius of the vertex arc is 1.8-2.9 times that of the pipe wall arc, preferably 2.2-2.4 times. The above-mentioned radius is the optimal radius obtained through a large number of numerical simulations and experimental studies. With this radius, the heat exchange effect of the two fluids inside and outside the pipe can be made as uniform as possible, achieving the best heat exchange effect.

[0031] This invention also discloses a heat exchanger. For example... Figure 7 As shown, the heat exchanger includes a shell 2, heat exchange tubes 1, a first fluid inlet pipe 3, an inlet end cap 4, and an outlet end cap 5. The first fluid inlet pipe 3 is disposed on the shell 2. A second fluid inlet pipe 6 and a mixed fluid outlet pipe 7 are respectively disposed on the inlet end cap 4 and the outlet end cap 5. An inlet tube sheet 8 is disposed between the inlet end cap 4 and the shell 2, and an outlet tube sheet 9 is disposed between the outlet end cap 5 and the shell 2. The heat exchange tubes 1 are disposed in the shell 2. The first end 14 and the second end 15 of the heat exchange tubes are fixedly connected to the inlet tube sheet 8 and the outlet tube sheet 9, respectively. The first end is connected to the inlet end cap 4, and the second end is not connected to the outlet end cap 5. The outlet tube sheet is provided with a through hole 10 connecting the shell and the outlet end cap. The heat exchange tubes are the first... Figure 1-5 The heat exchange tubes.

[0032] The first fluid enters the heat exchange tube 1 through the first fluid inlet pipe 6 and the end cap 4, and then exits through the injection hole 13 of the heat exchange tube 1. Because the second end of the heat exchange tube 1 is a closed structure, the first fluid cannot directly enter the outlet end cap 5 through the second end, and therefore must flow out through the injection hole 13. The second fluid flows in through the second fluid inlet pipe 3, and then mixes and exchanges heat directly with the first fluid flowing out through the injection hole 13 inside the tube shell 2. The heat-exchanged fluid enters the outlet end cap through the through hole of the outlet tube sheet, and then flows out from the fluid outlet pipe.

[0033] As an improvement, the heat exchange tubes 1 are arranged in a triangular pattern, with the centers of the arcs between three adjacent heat exchange tubes converging at a single point. This application, through the triangular distribution of the heat exchange tubes within the heat exchanger, combined with the corresponding triangular shape of the heat exchange tubes and the convergence of the centers of the arcs between three adjacent heat exchange tubes, achieves better mixing and improves heat exchange efficiency. The triangular tubes and triangular arrangement of this invention are mutually complementary and inseparable; their combined effect optimizes the mixing and heat exchange performance.

[0034] As an improvement, the second fluid is steam, and the shell-and-tube heat exchanger is a horizontal type. The distribution density of the injection holes on different heat exchange tubes varies, increasing from bottom to top. Because steam has a low density, it tends to accumulate in the upper part of the tube as it flows. Therefore, by increasing the injection hole density on the upper heat exchange tubes, the amount of the first fluid injected increases at the top, allowing more fluid to mix and exchange heat with the upper steam. This optimizes the overall heat exchange effect and improves the mixing heat exchange efficiency.

[0035] As an improvement, the distribution density of the injection holes in different heat exchange tubes increases progressively from bottom to top. This arrangement further optimizes the overall heat exchange effect and improves the efficiency of mixed heat exchange.

[0036] Preferably, the density of the injection holes increases from the center of the arc towards both sides. This is because research has shown that the fluid injection volume is highest in the center. By adjusting the density of the injection holes, the overall injection can be made more uniform, thus improving the mixing and heat exchange efficiency.

[0037] Preferably, the distribution density of the injection holes increases progressively from the center of the arc towards both sides. This arrangement further optimizes the overall heat exchange effect and improves the mixing heat exchange efficiency.

[0038] As an improvement, the second fluid is steam, and the first fluid is liquid.

[0039] As an improvement, multiple baffles are installed inside the shell, including a lower baffle located at the bottom of the shell and an upper baffle located at the top of the shell, with the lower and upper baffles spaced apart. By installing baffles, the liquid flows in a tortuous manner, improving the heat exchange effect.

[0040] As an improvement, the spacing between adjacent baffles gradually increases from the shell-side inlet to the outlet. This is because the flow rate of the fluid in the shell-side continuously increases from the inlet to the outlet as mixing and heat transfer proceed. If the spacing remains constant, the flow velocity would increase, causing scouring of the shell-side outlet and increasing flow resistance. By increasing the spacing, the flow velocity remains relatively stable, thus ensuring a relatively balanced resistance throughout the flow process and preventing a decline in heat transfer efficiency due to increased downstream resistance.

[0041] As an improvement, the spacing between adjacent baffles gradually increases from the shell-side inlet to the outlet. This increasing spacing further balances the resistance throughout the flow process.

[0042] As an improvement, the heat exchange tubes are configured in multiple segments along the direction from the shell-side inlet to the outlet, with each segment having a different arc radius.

[0043] As an improvement, the curvature of the arc gradually decreases along the direction from the shell-side inlet to the outlet. By reducing the curvature, the flow area inside the heat exchange tube becomes larger, thereby gradually reducing the flow resistance towards the outlet. This results in more fluid flowing towards the outlet from inside the tube, leading to a more balanced amount of fluid ejected along the entire heat exchange tube direction, thus promoting heat transfer.

[0044] As an improvement, the rate of decrease in the curvature of the arc in different sections gradually increases along the direction from the shell-side inlet to the outlet. By varying the rate of decrease in the curvature, the amount of fluid injected along the entire heat exchange tube direction is further made relatively uniform, thereby further promoting heat transfer.

[0045] While the present invention has been disclosed above with reference to preferred embodiments, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A triangular jet heat exchange tube, wherein the heat exchange tube has a triangular cross-section, and the lines connecting adjacent vertices of the triangle form an equilateral triangle, and a tube wall is formed between adjacent vertices. The tube wall is arc-shaped, and the curvature of the arc is toward the inner center of the equilateral triangle. A jet hole is formed on the tube wall to spray from the inside of the heat exchange tube to the outside of the tube.

2. The heat exchange tube as described in claim 1, characterized in that, The three arcs of the heat exchange tube have the same diameter and the same curvature.

3. The heat exchange tube as described in claim 1, characterized in that, The extension line of the spray direction of the spray hole points towards the inner center of the equilateral triangle.

4. The heat exchange tube as described in claim 3, characterized in that, The arc has an radian angle of 20-70°.

5. The heat exchange tube as described in claim 3, characterized in that, The arc has an angle of 40-50°.

6. A heat exchanger, comprising a shell, heat exchange tubes, a liquid inlet pipe, an inlet end cap, and an outlet end cap, wherein a first fluid inlet pipe is disposed on the shell, and a second fluid inlet pipe and a mixed fluid outlet pipe are respectively disposed on the inlet end cap and the outlet end cap; an inlet tube sheet is disposed between the inlet end cap and the shell, and an outlet tube sheet is disposed between the outlet end cap and the shell, wherein the heat exchange tubes are disposed in the shell, and a first end and a second end of the heat exchange tubes are respectively fixedly connected to the inlet tube sheet and the outlet tube sheet, wherein the first end communicates with the inlet end cap, and the second end is not communicated with the outlet end cap; the outlet tube sheet is provided with a through hole communicating with the shell and the outlet end cap, characterized in that... The heat exchange tube is the heat exchange tube according to any one of claims 1-5.

7. The heat exchanger as described in claim 6, characterized in that, The heat exchange tubes are arranged in a triangular pattern, with the centers of the arcs between three adjacent heat exchange tubes at the same point.

8. The heat exchanger as described in claim 6, characterized in that, Shell-and-tube heat exchangers are horizontal shell-and-tube heat exchangers. The distribution density of the injection holes of different heat exchange tubes is different. Along the height direction from bottom to top, the distribution density of the injection holes of different heat exchange tubes increases.

9. The heat exchanger as described in claim 8, characterized in that, Along the vertical direction from bottom to top, the distribution density of the injection holes of different heat exchange tubes increases by a significant margin.

10. The heat exchanger as claimed in claim 6, characterized in that, The second fluid is steam, and the first fluid is liquid.

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