Shell-and-tube heat exchanger and heat exchange system thereof

Abstract

The invention provides a shell-and-tube heat exchanger and a heat exchange system thereof.The heat exchanger comprises a shell, a heat tube, a liquid inlet tube, a liquid outlet tube, a left plug and a right plug, the left plug and the right plug are arranged at openings in the two ends of the shell respectively, and the liquid inlet tube and the liquid outlet tube are arranged on the upper side and the lower side of the shell respectively; the heat pipes comprise the left heat pipe and the right heat pipe, the heat absorption end of the left heat pipe is fixed to the left plug, the heat release end of the left heat pipe extends towards the right plug, the heat absorption end of the right heat pipe is fixed to the right plug, the heat release end of the right heat pipe extends towards the left plug, and the heat absorption ends of the left heat pipe and the right heat pipe are thermally connected with a heat source. And the left heat pipes and the right heat pipes are arranged at intervals. Uniform heat exchange is achieved on the whole, and the heat exchange effect is improved.

Description

Technical Field

[0001] This invention belongs to the field of heat exchange, and particularly relates to shell-and-tube heat pipe heat exchangers and their heat exchange systems. Background Technology

[0002] Shell-and-tube heat exchangers are widely used in industries such as power generation, chemical engineering, and oil refining, accounting for approximately 70% of all heat exchangers. Currently, most shell-and-tube heat exchangers consist of a tube box, tube shell, tube sheet, heat exchange tubes, and fluid inlet / outlet. Specifically, the heat exchange tubes pass through and are sealed between two tube sheets at both ends. Two tube boxes are sealed to two tube sheets (on the side of the tube sheet where the heat exchange tubes are connected). The tube shell is located outside the heat exchange tubes, between the two tube sheets, and together with the tube sheets and heat exchange tubes, forms a sealed heat exchange chamber. One type of fluid requiring heat exchange enters through an inlet on one tube box, flows through the tube box space into the inside of the heat exchange tubes connected to the tube sheet, longitudinally flushes the inside of the heat exchange tubes, and after heat exchange, enters the tube box on the other side, then exits through the tube box space and the fluid outlet connected to the tube box. The other type of fluid requiring heat exchange enters the tube shell through a fluid inlet connected to the tube shell, flushes the outside of the heat exchange tubes for heat exchange, and then exits the tube shell through a fluid outlet connected to the tube shell.

[0003] A heat pipe utilizes the phase change process of a medium evaporating at the hot end and condensing at the cold end (i.e., utilizing the latent heat of vaporization and condensation of the liquid) to rapidly conduct heat. A typical heat pipe consists of a shell, a wick, and end caps. The inside of the heat pipe is evacuated to a negative pressure state and filled with a suitable liquid with a low boiling point and high volatility. The pipe wall has a wick made of a capillary porous material. One end of the heat pipe is the evaporation end, and the other end is the condensation end. When one end of the heat pipe is heated, the liquid in the capillary rapidly vaporizes. The vapor flows to the other end under the force of thermal diffusion, condenses at the cold end, and releases heat. The liquid then flows back to the evaporation end along the porous material by capillary action. This cycle continues until the temperature at both ends of the heat pipe is equal (at which point thermal diffusion of the vapor stops). This cycle is rapid, and heat can be continuously conducted.

[0004] In the prior art, CN102288055A discloses a heat pipe shell-and-tube heat exchanger, including a shell, a fluid inlet and a fluid outlet formed on the shell, a tube sheet, and heat exchange tubes fixed on the tube sheet. A closed heat exchange cavity is formed inside the shell, and the heat exchange tubes are disposed within the heat exchange cavity. The tube sheet divides the heat exchange cavity into a first heat exchange cavity and a second heat exchange cavity. Part of the heat exchange tubes are located in the first heat exchange cavity, and part are located in the second heat exchange cavity. The first heat exchange cavity has a first fluid inlet and a first fluid outlet; the second heat exchange cavity has a second fluid inlet and a second fluid outlet. The heat exchange tubes are heat pipes. This invention uses high-efficiency heat pipes, improving the structure of the shell-and-tube heat exchanger. It prevents thermal stress from occurring at the connection points between the heat pipes, tube sheet, and shell, and can adapt to heat exchange between fluids with large temperature differences. Both sides employ transverse scouring, resulting in high heat exchange efficiency, simple structure, and convenient arrangement.

[0005] CN118602848A provides an intelligent control heat exchanger system. An inlet valve is installed on the bypass pipe between the heat exchanger and the main pipeline to control the opening and closing of the heat exchanger inlet pipe and the fluid flow rate. An outlet valve is installed on the bypass pipe between the outlet pipe and the main pipeline to control the opening and closing of the bypass pipe. The system also includes a controller, which is connected to a temperature sensor, the outlet valve, the main valve, the inlet valve, and the outlet valve. This invention, by implementing an intelligent control heat exchanger system, ensures that the outlet fluid remains within a certain range, preventing temperature discrepancies. When the temperature is below the required level, the internal circulation of the fluid continues until the required temperature is reached, thereby achieving energy savings.

[0006] The aforementioned technologies suffer from the following problems: the evaporation and condensation sections of shell-and-tube heat pipe heat exchangers are completely separated, with one section absorbing heat completely and the other releasing heat completely, potentially causing uneven local heat release temperatures along the direction of heat release. Furthermore, existing heat exchange systems suffer from uneven heat exchange, poor heat transfer efficiency, and complex heat exchanger structures, requiring an external fluid heat source.

[0007] To address the aforementioned problems, this invention improves the heat exchanger by optimizing the distribution of heat pipes, thereby achieving uniform heat exchange of the fluid within the heat exchanger and enhancing the overall heat exchange effect. Summary of the Invention

[0008] This invention provides a novel heat exchanger and its heat exchange system, thereby solving the aforementioned technical problems.

[0009] To achieve the above objectives, the technical solution of the present invention is as follows: A shell-and-tube heat pipe heat exchanger includes a shell, heat pipes, a liquid inlet pipe, a liquid outlet pipe, a left end cap, and a right end cap. The shell has openings at both ends, with the left and right end caps respectively. The liquid inlet pipe and liquid outlet pipe are respectively located on the upper and lower sides of the shell. The heat pipes include a left heat pipe and a right heat pipe. The heat-absorbing end of the left heat pipe is fixed to the left end cap, and the heat-releasing end extends towards the right end cap. The heat-absorbing end of the right heat pipe is fixed to the right end cap, and the heat-releasing end extends towards the left end cap. The heat-absorbing ends of the left and right heat pipes are thermally connected to a heat source. Viewed from the cross-section of the shell, the left and right heat pipes are spaced apart.

[0010] As an improvement, when viewed from the cross-section of the tube shell, the left heat pipe is arranged in an equilateral triangle, and the right heat pipe is located at the center of the triangle of the left heat pipe.

[0011] As an improvement, the left heat pipe is arranged in a square, and the right heat pipe is located at the center of the square of the left heat pipe.

[0012] As an improvement, the heat source is a resistance heater, which is located inside the left and right plugs.

[0013] As an improvement, the left and right plugs are made of insulating material.

[0014] As an improvement, one side of the resistance heater rests against the left or right plug, while the other side is thermally connected to the fluid.

[0015] As an improvement, a baffle plate is included, comprising a first baffle plate extending downward from top to bottom and a second baffle plate extending upward from bottom to top, wherein the first baffle plate and the second baffle plate are spaced apart.

[0016] As an improvement, the end of the heat-dissipating end of the left heat pipe is not thermally connected to the heat source on the right, and the end of the heat-dissipating end of the right heat pipe is not thermally connected to the heat source on the left.

[0017] A heat exchange system includes a circulation pipe and a heat exchanger, the heat exchanger being the aforementioned heat exchanger. The circulation pipe connects the fluid inlet pipe and the liquid outlet pipe of the heat exchanger. An outlet pipe is provided on the circulation pipe connected to the liquid outlet pipe for discharging the fluid from the circulation pipe. An outlet valve is provided on the outlet pipe.

[0018] As an improvement, a temperature sensor is installed on the liquid outlet pipe to detect the outlet temperature of the fluid, and the opening and closing of the outlet valve is determined based on the temperature detected by the temperature sensor.

[0019] As an improvement, the spacing between the baffles gradually increases from both ends to the middle.

[0020] Compared with the prior art, the present invention has the following advantages: This invention features heat pipes with heat absorption ends on both sides of the left and right end caps, extending to heat release ends in the opposite direction. The left and right heat pipes are spaced apart, so that the location of the left heat pipe with a large heat exchange capacity corresponds to the location of the right heat pipe with a small heat exchange capacity. This ensures that the heat exchange capacity is relatively consistent at different cross-sectional locations of the tube shell, thereby achieving uniform heat exchange along the overall length of the tube shell and improving the overall heat exchange effect. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the shell-and-tube heat pipe heat exchanger structure of the present invention; Figure 2 This is a schematic diagram of the heat exchange system structure of the present invention. Detailed Implementation

[0022] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0023] Unless otherwise specified, the left and right mentioned in this invention are relative positions and are not required to be set to left and right.

[0024] Figure 1 The shell-and-tube heat pipe heat exchanger of the present invention is disclosed. Preferably, it is a horizontal shell-and-tube heat exchanger. For example... Figure 1 As shown, a shell-and-tube heat pipe heat exchanger includes a shell 1, heat pipes 2, a liquid inlet pipe 3, a liquid outlet pipe 4, a left plug 5, and a right plug 6. The shell 1 has openings at both ends, with the left plug 5 and right plug 6 respectively for sealing the shell. The liquid inlet pipe 3 and liquid outlet pipe 4 are respectively located on the upper and lower sides of the shell. The heat pipes include a left heat pipe 21 and a right heat pipe 22. The heat-absorbing end of the left heat pipe 21 is fixed to the left plug, and the heat-releasing end extends towards the right plug. The heat-absorbing end of the right heat pipe 22 is fixed to the right plug, and the heat-releasing end extends towards the left plug. The heat-absorbing ends of the left and right heat pipes are thermally connected to a heat source 7. Viewed from the cross-section of the shell, the left heat pipe 21 and right heat pipe 22 are spaced apart.

[0025] This invention features heat pipes with heat absorption ends on both sides of the left and right end caps, extending to heat release ends in the opposite direction. The left and right heat pipes are spaced apart, ensuring that locations with high heat exchange capacity on the left heat pipe correspond to locations with low heat exchange capacity on the right heat pipe, and vice versa. This intermittent arrangement of the left and right heat pipes achieves heat complementarity, resulting in relatively consistent heat exchange across different cross-sectional areas of the tube shell. This leads to uniform heat exchange along the entire length of the tube shell, thereby improving the overall heat exchange efficiency.

[0026] By employing a heat pipe, this invention enables the fluid inside the heat pipe to rapidly evaporate and expand to a location far from the heat-absorbing section, releasing heat even when the heat absorption section absorbs only a small amount of heat. Compared to ordinary heat exchange tubes, this allows for rapid long-distance heat exchange.

[0027] As an improvement, the liquid inlet pipe is located on the upper part of the pipe shell near the left plug, and the liquid outlet pipe is located on the lower part of the pipe shell near the right plug.

[0028] As an improvement, when viewed from the cross-section of the tube shell, the left heat pipe is arranged in an equilateral triangle, with the right heat pipe positioned at the center of the triangle formed by the left heat pipe. This arrangement ensures that the left heat pipe is surrounded by right heat pipes, and vice versa, thereby further promoting a more balanced heat exchange at different locations on the tube shell's cross-section and improving the heat exchange efficiency.

[0029] As an improvement, the left heat pipes are arranged in a square, with the right heat pipe positioned at the center of the square of the left heat pipes. This arrangement ensures that the left heat pipes are surrounded by right heat pipes, and vice versa, thereby further promoting a more balanced heat exchange across different locations on the pipe shell cross-section and improving the heat exchange efficiency.

[0030] As an improvement, such as Figure 1 As shown, the heat source 7 is a resistance heater, which is disposed inside the left and right end caps. By using a resistance heater, a heat exchanger fluid is not required, unlike in previous applications, thus simplifying the heat exchanger structure.

[0031] As an improvement, the left and right plugs are made of insulating material. This insulation helps prevent heat loss.

[0032] As an improvement, one side of the resistance heater rests against the left or right end cap, while the other side is thermally connected to the fluid. With this configuration, the resistance heater can not only heat the heat pipe but also directly heat the fluid in contact with it, thereby further improving the heat exchange effect.

[0033] As an improvement, such as Figure 1 As shown, the heat exchanger includes a baffle plate 8, which includes a first baffle plate extending downward and a second baffle plate extending upward, with the first baffle plate and the second baffle plate being spaced apart.

[0034] As an improvement, the spacing between adjacent baffles gradually increases from both ends of the shell 1 towards the middle. Specifically, in the middle position, the temperatures of the left and right heat pipes are essentially the same, with no temperature difference across the entire shell cross-section, resulting in the best heat exchange effect. At the ends, the temperature difference between the left and right heat pipes is the greatest, leading to the worst and most uneven heat exchange. Therefore, by reducing the spacing between the baffles at the ends, the fluid velocity is increased, enhancing convection and making the overall heat exchange more uniform, further improving the heat exchange effect.

[0035] As an improvement, the spacing between adjacent baffles gradually increases from both ends of the tube shell 1 towards the middle. By varying the spacing between the baffles, the overall heat transfer becomes more uniform, further improving the heat transfer effect.

[0036] As an improvement, protrusions are set on the outside of the heat pipe to increase the heat exchange area, disrupt the laminar flow layer, improve the heat exchange effect, and enhance heat transfer.

[0037] As an improvement, the density of the protrusions gradually increases from the middle of the shell 1 towards the left and right ends. Specifically, in the middle, the temperatures of the left and right heat pipes are essentially the same, with no temperature difference across the entire shell cross-section, resulting in the best heat exchange effect. At the ends, the temperature difference between the left and right heat pipes is the greatest, leading to the worst and most uneven heat exchange. Therefore, by increasing the number of protrusions at the ends, the fluid heat exchange area is increased, further disrupting the laminar sublayer and enhancing convection, thus making the overall heat exchange more uniform and further improving the heat exchange effect.

[0038] As an improvement, the distribution density of the protrusions gradually increases from the middle of the tube shell 1 to both ends. This variation in density further enhances the overall uniformity of heat transfer and improves the heat exchange efficiency.

[0039] As an improvement, such as Figure 1 As shown, the end of the heat-dissipating end of the left heat pipe is not thermally connected to the heat source on the right, and the end of the heat-dissipating end of the right heat pipe is not thermally connected to the heat source on the left. By avoiding contact, the heat source can be prevented from heating the condensing end, thus avoiding disruption of the overall heat exchange balance.

[0040] As an improvement, the length of the heat pipe is 95-98% of the shell length. This length ensures both the heat exchange area and avoids the influence of the heat source on the heat dissipation end.

[0041] As an improvement, a capillary structure is installed inside the heat pipe to introduce the fluid condensed at the heat-releasing end into the heat-absorbing section, thereby forming a circulation inside the heat pipe.

[0042] As an improvement, the heat source is located only at the heat-absorbing end of the heat pipe. Preferably, it is located at the heat-absorbing end inside the heat pipe. The fluid inside the heat pipe evaporates by heating the heat-absorbing section, then releases heat at the heat-releasing end, and after condensation, it circulates back to the heat-absorbing end.

[0043] As an improvement, the power of the heat source for each heat pipe can be controlled by a controller.

[0044] As an improvement, when viewed from the cross-section of the tube shell, the heating power of the heat source gradually increases from the center to the edge of the cross-section. Because the heat exchange efficiency is best in the middle and worst at the periphery, by varying the heating power, the heat exchange efficiency across the entire cross-section is made to be essentially the same, thereby improving the overall heat exchange efficiency.

[0045] As an improvement, when viewed from the cross-section of the tube shell, the heating power of the heat source gradually increases from the center of the cross-section to the edge. This variation in heating power further enhances heat exchange efficiency.

[0046] Figure 2 A heat exchange system is disclosed. For example... Figure 2 As shown, the heat exchange system includes a circulation pipe 10 and a heat exchanger 9, which is the one mentioned earlier. Figure 1 The heat exchanger has a circulation pipe 10 connecting the fluid inlet pipe 3 and the liquid outlet pipe 4. A discharge pipe 12 is installed on the circulation pipe connected to the liquid outlet pipe to discharge the fluid from the circulation pipe. A discharge valve 13 is installed on the discharge pipe. The fluid from the circulation pipe is discharged for use by opening and closing the discharge valve.

[0047] As an improvement, a temperature sensor is installed on the liquid outlet pipe 4 to detect the outlet temperature of the fluid, and the opening and closing of the outlet valve is determined based on the temperature detected by the temperature sensor.

[0048] In a further improvement, the heat exchange system includes a replenishment pipe 15, on which a replenishment valve 16 is installed. The replenishment function is achieved by opening and closing the replenishment valve.

[0049] As an improvement, when the temperature detected by the temperature sensor is lower than the lower limit or higher than the upper limit, the controller closes the outlet valve, and the fluid continues to flow in the circulation pipe.

[0050] As an improvement, when the temperature detected by the temperature sensor is between the upper and lower limits, the controller controls the outlet valve to open, allowing the fluid to be discharged.

[0051] As an improvement, the system is equipped with an alarm, and the controller issues a low-temperature or high-temperature alarm signal based on the temperature monitored by the temperature sensor.

[0052] Through the aforementioned intelligent control, the extracted fluid can be kept within a certain range to avoid temperature discrepancies. If the temperature does not meet the requirements, the internal circulation of the fluid continues until the temperature meets the requirements.

[0053] As an improvement, fluid is liquid.

[0054] As an improvement, fluid temperature control is achieved by adjusting the heating power of the heat source. When the monitored temperature is too high, the controller reduces the heating power of the heat source; when the monitored temperature is too low, the controller increases the heating power of the heat source, thereby automatically controlling the outlet temperature and achieving energy conservation.

[0055] As an improvement, a circulation pump 11 is installed on the circulation pipeline.

[0056] 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 shell-and-tube heat pipe heat exchanger, the heat exchanger comprising a shell, heat pipes, a liquid inlet pipe, a liquid outlet pipe, a left plug, and a right plug, wherein the shell has openings at both ends and a left plug and a right plug are respectively disposed thereon, and the liquid inlet pipe and the liquid outlet pipe are respectively disposed on the upper and lower sides of the shell, characterized in that, The heat pipe includes a left heat pipe and a right heat pipe. The heat-absorbing end of the left heat pipe is fixed to the left end cap, and the heat-releasing end extends towards the right end cap. The heat-absorbing end of the right heat pipe is fixed to the right end cap, and the heat-releasing end extends towards the left end cap. The heat-absorbing ends of the left and right heat pipes are thermally connected to a heat source. When viewed from the cross-section of the pipe shell, the left and right heat pipes are spaced apart.

2. The shell-and-tube heat pipe heat exchanger as described in claim 1, characterized in that, Viewed from the cross-section of the tube shell, the left heat pipe is arranged in an equilateral triangle, and the right heat pipe is located at the center of the triangle of the left heat pipe.

3. The shell-and-tube heat pipe heat exchanger as described in claim 1, characterized in that, The left heat pipes are arranged in a square, and the right heat pipe is located at the center of the square of the left heat pipes.

4. The shell-and-tube heat exchanger as described in claim 1, characterized in that, The heat source is a resistance heater, which is located inside the left and right plugs.

5. The shell-and-tube heat pipe heat exchanger as described in claim 4, characterized in that, The left and right plugs are made of insulating material.

6. The shell-and-tube heat pipe heat exchanger as described in claim 4, characterized in that, One side of the resistance heater rests against the left or right plug, while the other side is thermally connected to the fluid.

7. The shell-and-tube heat pipe heat exchanger as described in claim 1, characterized in that, It includes a baffle plate, which includes a first baffle plate extending downward from top to bottom and a second baffle plate extending upward from bottom to top, with the first baffle plate and the second baffle plate being spaced apart.

8. The shell-and-tube heat pipe heat exchanger as described in claim 1, characterized in that, The end of the heat-dissipating end of the left heat pipe is not thermally connected to the heat source on the right, and the end of the heat-dissipating end of the right heat pipe is not thermally connected to the heat source on the left.

9. A heat exchange system, comprising a circulation pipe and a heat exchanger, wherein the heat exchanger is the heat exchanger as described in any one of claims 1-8, the circulation pipe connecting the fluid inlet pipe and the liquid outlet pipe of the heat exchanger, and an outlet pipe provided on the circulation pipe connected to the liquid outlet pipe for discharging the fluid from the circulation pipe, wherein an outlet valve is provided on the outlet pipe.

10. The heat exchange system as described in claim 9, characterized in that, A temperature sensor is installed on the liquid outlet pipe to detect the outlet temperature of the fluid, and the opening and closing of the outlet valve is determined based on the temperature detected by the temperature sensor.

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