Vacuum heat exchange system

Abstract

The utility model discloses a vacuum heat exchange system, belongs to the technical field of heat exchangers, solves the problem of low heat exchange efficiency of a vacuum heat exchanger in the prior art, and adopts the technical scheme that the vacuum heat exchange system comprises a plate heat exchanger and a tubular heat exchanger, a flue for circulating flue gas is formed between the heat exchange plates, a first flowing cavity is formed in each heat exchange plate, a phase change material is arranged in each first flowing cavity, a plurality of heat exchange pipes arranged at intervals are arranged in the tubular heat exchanger, and heat exchange channels for flowing the phase change material are formed between the heat exchange pipes. A second flowing cavity used for flowing of fluid to be subjected to heat exchange is formed in the heat exchange pipe, the upper end of the first flowing cavity is connected with the upper side of the heat exchange channel through a first pipeline, and the lower side of the heat exchange channel is connected with the lower end of the first flowing cavity through a backflow pipe. The vacuum heat exchanger is mainly used for improving the heat exchange efficiency of the heat exchange tubes in the vacuum heat exchanger.

Description

Technical Field

[0001] This application relates to the field of heat exchanger technology, and in particular to a vacuum heat exchange system. Background Technology

[0002] In existing vacuum heat exchange systems, insufficient contact area often leads to low heat exchange efficiency when heat exchange tubes are used for heat exchange in flue gas. A common solution is to add a threaded ring to the outer surface of the heat exchange tube to increase the contact area with the flue gas. However, this causes dust in the flue gas to accumulate on the leeward side of the threaded ring, resulting in corrosion of the heat exchange tube at the threaded ring and leakage of the phase change material. To address this technical problem, placing a corrugated heat exchange plate on the flue gas side for heat exchange can effectively solve the corrosion problem of the heat exchanger on the flue gas side. However, due to the large number of welding points on the heat exchange plate, and the leakage caused by pressure fluctuations during heat exchange with the fluid to be exchanged, the fluid to be exchanged also leaks. Therefore, heat exchange tubes are used for heat exchange with the fluid to be exchanged.

[0003] During the heat exchange process in the heat exchange tube, the phase change material will turn into a liquid and flow downward due to heat release. In the existing technology, the gaseous phase change material rises and the liquid phase change material flows downward in the same pipe. This causes the gaseous phase change material to a certain extent to cool down due to contact with the liquid phase change material, which reduces the heat exchange efficiency of the heat exchange tube and wastes the temperature transfer in the flue gas. Summary of the Invention

[0004] In order to overcome the shortcomings of low heat exchange efficiency in existing vacuum heat exchangers, this application provides a vacuum heat exchange system that can increase the heat exchange efficiency of heat exchange tubes in a vacuum heat exchanger.

[0005] To achieve the above objectives, this application adopts the following technical solution: a vacuum heat exchange system, comprising a plate heat exchanger and a tubular heat exchanger, wherein the plate heat exchanger is provided with multiple spaced heat exchange plates, and a flue is formed between the heat exchange plates for circulating flue gas; a first flow cavity is provided within the heat exchange plates, and a phase change material is provided within the first flow cavity; the tubular heat exchanger is provided with multiple spaced heat exchange tubes, and a heat exchange channel for flowing phase change material is formed between the heat exchange tubes; a second flow cavity is provided within the heat exchange tubes for flowing fluid to be heat exchanged; the upper end of the first flow cavity is connected to the upper side of the heat exchange channel through a first pipe, and the lower side of the heat exchange channel is connected to the lower end of the first flow cavity through a return pipe.

[0006] With the above technical solution, when the flue gas flows in the flue, heat is transferred to the heat exchange plate, causing the phase change material in the first flow chamber to absorb heat and undergo a phase change to a gaseous state. The gaseous phase change material, entering the upper side of the heat exchange channel from the upper end of the first flow chamber through the first pipe, exchanges heat with the fluid to be heat-exchanged in the heat exchange tube. After releasing heat, the gaseous phase change material reverts to a liquid state, flows down the side wall of the heat exchange channel, and returns to the lower end of the first flow chamber through the return pipe, completing the circulation of the phase change material. The fluid to be heat-exchanged absorbs heat from the phase change material in the second flow chamber, causing its temperature to rise, thus achieving heating or temperature increase of the fluid. This design achieves heat transfer between the flue gas, the phase change material, and the fluid to be heat-exchanged, achieving the purpose of heat exchange. This application has the following advantages: by allowing the gaseous phase change material to enter from the upper side of the heat exchange channel through the first pipe and the liquid phase change material to flow out from the lower side of the heat exchange channel through the return pipe, the flow paths of the gaseous and liquid phase change materials are relatively independent, avoiding the situation where the gaseous phase change material cools down due to contact with the liquid phase change material during the flow process or the gaseous phase change material dissolves into the liquid phase change material, thus ensuring the heat exchange efficiency of the flue gas to the fluid to be heat exchanged.

[0007] Furthermore, the return pipe is divided into a second pipe and a third pipe. The lower end of the first flow chamber is connected to a water collection tank through the second pipe. The water collection tank is connected to the lower side of the heat exchange channel through the third pipe. The diameter of the third pipe is larger than that of the first pipe, and the number of third pipes is less than that of the first pipe. The diameter of the third pipe is larger than that of the second pipe, and the number of third pipes is less than that of the second pipe.

[0008] By adopting the aforementioned technical solution, the larger diameter of the third pipe provides more spacious flow space for the liquid phase change material flowing from the water collection tank to the lower side of the heat exchange channel, reducing flow resistance and allowing the liquid phase change material to flow back to the heat exchange channel more smoothly. This helps maintain the circulation efficiency of the phase change material in the system and ensures the stability of the heat exchange process. The relatively small number of third pipes reduces the amount of pipe material used while meeting the system's functional requirements, thus lowering the system's construction cost. Furthermore, the larger pipe diameter reduces the number of pipe connections, further reducing material and installation costs.

[0009] Furthermore, the heat exchange plate is formed by welding two thin plates together with a welding wire, so that the first flow cavity is divided into several mutually isolated heat exchange cavities by the welding wire.

[0010] The aforementioned technical solution involves welding heat exchange plates using weld points or weld rings. This results in multiple weld initiation and termination points during welding, leading to repeated arc initiation and termination. A single heat exchange plate can have thousands of weld points or weld rings, making it susceptible to defects due to improper welding during manufacturing. This makes the heat exchange plate vulnerable to damage from particle impacts in the flue gas during use. This design, however, uses wire bonding to weld the heat exchange plate, resulting in a higher yield rate during welding. Furthermore, dividing the first flow cavity into several isolated heat exchange chambers increases the contact area between the phase change material and the fluid (flue gas) outside the heat exchange plate. This allows the phase change material to more fully absorb heat from the flue gas and transfer it more efficiently to the fluid being exchanged, thereby improving heat exchange efficiency.

[0011] Furthermore, a second pipe is connected to each heat exchange chamber, and the second pipe is interconnected through the water collection tank so that the heat exchange chambers connected to the second pipes are interconnected.

[0012] By employing the aforementioned technical solution, since each heat exchange chamber is interconnected via a second pipe and a water collection tank, when the pressure in a heat exchange chamber changes due to heat exchange, the fluid can flow between the heat exchange chambers through the second pipe, thereby balancing the pressure in each heat exchange chamber and preventing equipment damage or impact on heat exchange efficiency due to uneven pressure. Furthermore, because the heat exchange chambers are isolated from each other, the heat exchange efficiency varies at different locations, resulting in different phase change rates for the phase change materials. To ensure timely supply of phase change materials to the heat exchange chambers, the second pipes connecting the heat exchange chambers are interconnected via the water collection tank, allowing heat exchange chambers with faster phase change rates to quickly replenish phase change materials, thus balancing the phase change materials in each heat exchange chamber.

[0013] Furthermore, the tubular heat exchanger is provided with a shell for fitting over the heat exchange tubes, the shell having an interface communicating with the heat exchange channel, and an air extraction device being detachably connected to the interface.

[0014] By employing the aforementioned technical solution, reducing the gas pressure within the heat exchange channel allows the phase change material to undergo a phase change at a lower boiling point. This enables the phase change material to absorb heat more quickly and transition from a liquid to a gaseous state at the same heat source temperature, accelerating the phase change process and thus improving the overall system's heat exchange efficiency. The gaseous phase change material can exchange heat with the fluid being heated more rapidly, resulting in more efficient heat transfer. Furthermore, since plate heat exchangers have multiple heat exchange plates, only one interface is needed on a tubular heat exchanger, which is more convenient than requiring multiple interfaces on a plate heat exchanger. Additionally, when extracting internal gas, the heat exchange channel space of the tubular heat exchanger is larger than the first flow chamber space inside the plate heat exchanger, allowing for a higher extraction rate and preventing the rapid contraction of the plates during extraction, which is common in plate heat exchangers.

[0015] Furthermore, the heat exchange tubes inside the tubular heat exchanger are U-shaped heat exchange tubes, with the two ends of the U-shaped heat exchange tubes being the inlet and outlet of the tubular heat exchanger, respectively.

[0016] By employing the aforementioned technical solution, the shape of the U-shaped heat exchange tube allows for an increase in the length of the heat exchange tube within a limited space, thereby increasing the heat exchange area and enhancing the heat exchange effect. Compared to straight-tube heat exchangers, U-shaped heat exchange tubes can achieve more efficient heat exchange within the same equipment volume, making the structure of the tube heat exchanger more compact and saving installation space.

[0017] Furthermore, the inlet of the tubular heat exchanger is located on the lower side, and the outlet of the tubular heat exchanger is located on the upper side of the tubular heat exchanger opposite to the inlet. A baffle is provided between the inlet and the outlet to extend the flow path of the fluid to be exchanged in the heat exchange tube.

[0018] Using the aforementioned technical solution, the inlet is located on the lower side and the outlet on the upper side. Because the gaseous phase change material within the heat exchange channel exhibits a distribution with high-temperature gas at the top and low-temperature gas at the bottom, the fluid to be heat-exchanged first exchanges heat with the low-temperature phase change material as it flows in from the bottom, and then gradually exchanges heat with the high-temperature phase change material. This results in higher heat exchange efficiency. The presence of the baffle not only extends the path of the fluid to be heat-exchanged but also promotes multiple turns and mixing during the flow process. This mixing effect makes the temperature and composition inside the fluid more uniform, avoiding excessive local differences and improving the overall heat exchange effect and product quality.

[0019] Furthermore, the first pipe is divided into a first vertical pipe connected to the upper end of the first flow chamber and a first horizontal pipe connected to the upper side of the heat exchange channel, and a number of first vertical pipes are connected to the side wall of the first horizontal pipe.

[0020] By adopting the aforementioned technical solution, dividing the first pipeline into a first horizontal pipe and multiple first vertical pipes, fewer pipes are used between the plate heat exchanger and the tube heat exchanger, resulting in material savings and reduced heat exchange system costs. The combination structure of the first pipeline into first vertical pipes and first horizontal pipes offers greater flexibility and convenience during installation. The length and angle of the first vertical pipes and first horizontal pipes can be adjusted according to the specific location and layout of the plate heat exchanger and the tube heat exchanger, making the connection smoother. In terms of maintenance, if a problem occurs in a section of the pipeline, it is easier to inspect, repair, or replace the first vertical pipe or first horizontal pipe individually, reducing maintenance difficulty and costs.

[0021] Furthermore, the height of the first vertical pipe is lower than the height of the connection between the first horizontal pipe and the heat exchange channel.

[0022] Using the aforementioned technical solution, after the gaseous phase change material enters the first vertical pipe from the first flow cavity, because the height of the first vertical pipe is lower than the connection between the first horizontal pipe and the heat exchange channel, gravity will cause the gaseous phase change material to flow more smoothly into the first horizontal pipe, and then into the heat exchange channel. This gravity-assisted flow method reduces the resistance of the gaseous phase change material in the pipe, ensuring the continuous and stable flow of the gaseous phase change material, and avoiding the problems of gaseous phase change material accumulation or poor flow caused by excessive resistance in the pipe.

[0023] Furthermore, the tubular heat exchanger is equipped with a pressure gauge for detecting the gas pressure inside the heat exchange channel.

[0024] Using the aforementioned technical solution, the pressure gauge can accurately display the pressure value within the heat exchange channel in real time. Operators can intuitively understand the current operating status of the system by observing the pressure gauge reading. By monitoring the pressure, the risk of equipment damage caused by excessive pressure, such as pipe rupture or seal failure, can be effectively prevented. Attached Figure Description

[0025] The following description, in conjunction with the accompanying drawings, further illustrates this application:

[0026] Figure 1 This is a schematic diagram of a vacuum heat exchange system according to this application;

[0027] Figure 2 for Figure 1 The left view;

[0028] Figure 3 This is a cross-sectional view of a tubular heat exchanger.

[0029] Figure descriptions: 1. Plate heat exchanger; 11. Heat exchange plate; 12. Flue; 13. First flow chamber; 14. Heat exchange chamber; 2. Tubular heat exchanger; 21. Heat exchange tube; 22. Second flow chamber; 23. Heat exchange channel; 24. Baffle; 3. First pipe; 31. First horizontal pipe; 32. First vertical pipe; 4. Return pipe; 41. Second pipe; 42. Third pipe; 43. Interface; 44. Inlet; 45. Outlet; 5. Water collection tank; 6. Pressure gauge. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0031] The terms "first," "second," etc. (if present) in the specification and claims of this application are used to distinguish similar objects, not to describe a specific order or sequence. Even if "second" is used before a technical feature for distinction, it does not necessarily imply the presence of "first." It should be understood that in this application, "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. It should be understood that in this application, "multiple" refers to two or more. "And / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, X and / or Y can represent: X alone, X and Y simultaneously, and Y alone. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "Containing X, Y, and Z," "Containing X, Y, and Z" means that all three X, Y, and Z are included; "Containing X, Y, or Z" means that one of X, Y, and Z is included; "Containing X, Y, and / or Z" means that any one, two, or three of X, Y, and Z are included.

[0032] The technical solutions of this application will be described in detail below with specific embodiments. The following specific embodiments can be combined or substituted with each other according to the actual situation, and the same or similar concepts or processes may not be described again in some embodiments.

[0033] like Figures 1 to 3As shown, this application provides a vacuum heat exchange system, including a plate heat exchanger 1 and a tubular heat exchanger 2. The plate heat exchanger 1 has multiple spaced heat exchange plates 11, and a flue duct 12 for circulating flue gas is formed between the heat exchange plates 11. A first flow cavity 13 is provided in the heat exchange plate 11, and a phase change material is provided in the first flow cavity 13. The tubular heat exchanger 2 has multiple spaced heat exchange tubes 21, and a heat exchange channel 23 for flowing phase change material is formed between the heat exchange tubes 21. A second flow cavity 22 for flowing fluid to be heat exchanged is provided in the heat exchange tube 21. The upper end of the first flow cavity 13 is connected to the upper side of the heat exchange channel 23 through a first pipe 3, and the lower side of the heat exchange channel 23 is connected to the lower end of the first flow cavity 13 through a return pipe 4.

[0034] With the above technical solution, when the flue gas flows in the flue 12, heat is transferred to the heat exchange plate 11, which in turn causes the phase change material in the first flow chamber 13 to absorb heat and undergo a phase change to a gaseous state. The gaseous phase change material enters the upper side of the heat exchange channel 23 from the upper end of the first flow chamber 13 of the plate heat exchanger 1 through the first pipe 3. In the heat exchange channel 23, it exchanges heat with the fluid to be heat exchanged in the heat exchange tube 21. After releasing heat, the gaseous phase change material turns back into a liquid phase change material, flows down the side wall of the heat exchange channel 23, and returns to the lower end of the first flow chamber 13 through the return pipe 4, completing the circulation of the phase change material. The fluid to be heat exchanged absorbs heat from the phase change material in the second flow chamber 22, and its temperature rises, thereby achieving the heating or temperature increase treatment of the fluid to be heat exchanged. Through this design, heat transfer between the flue gas, the phase change material, and the fluid to be heat exchanged is realized, achieving the purpose of heat exchange. This application has the following advantages: by allowing the gaseous phase change material to enter from the upper side of the heat exchange channel 23 through the first pipe 3 and the liquid phase change material to flow out from the lower side of the heat exchange channel 23 through the return pipe 4, the flow paths of the gaseous phase change material and the liquid phase change material are relatively independent, avoiding the situation where the gaseous phase change material does not cool down due to contact with the liquid phase change material during the flow process or the gaseous phase change material dissolves into the liquid phase change material, thus ensuring the heat exchange efficiency of the flue gas to the fluid to be heat exchanged.

[0035] Specifically, the phase change material can be one of the following: Freon, ethanol, acetone, water, etc.; preferably, the liquid level of the phase change material in the initial state is greater than or equal to the height of the heat exchange plate 11 in the flue 12, so that the phase change material can better contact the flue gas, thereby conducting heat and preventing the heat exchange plate 11 from dry burning.

[0036] Furthermore, the return pipe 4 is divided into a second pipe 41 and a third pipe 42. The lower end of the first flow chamber 13 is connected to a water collection tank 5 through the second pipe 41. The water collection tank 5 is connected to the lower side of the heat exchange channel 23 through the third pipe 42. The diameter of the third pipe is larger than that of the first pipe and the number of third pipes is less than that of the first pipe. The diameter of the third pipe is larger than that of the second pipe and the number of third pipes is less than that of the second pipe.

[0037] By adopting the aforementioned technical solution, the larger diameter of the third pipe provides more spacious flow space for the liquid phase change material flowing from the water collection tank 5 to the lower side of the heat exchange channel 23, reducing flow resistance and allowing the liquid phase change material to flow back to the heat exchange channel 23 more smoothly. This helps maintain the circulation efficiency of the phase change material in the system and ensures the stability of the heat exchange process. The relatively small number of third pipes reduces the amount of pipe material used while meeting the system's functional requirements, thus lowering the system's construction cost. Furthermore, the larger pipe diameter reduces the number of pipe connections, further reducing material and installation costs.

[0038] Furthermore, the heat exchange plate 11 is formed by welding two thin plates together with a welding wire, so that the first flow cavity 13 is divided into several mutually isolated heat exchange cavities 14 by the welding wire.

[0039] Using the aforementioned technical solution, the heat exchange plate 11 in the prior art is welded by weld points or weld rings. This results in multiple weld start and stop points during welding, leading to repeated arc initiation and termination. A single heat exchange plate 11 may have thousands of weld points or weld rings, which can cause weak points due to improper welding during manufacturing. This makes the heat exchange plate 11 susceptible to damage from particle impact in the flue gas during use. This design, however, welds the heat exchange plate 11 using wire bonding, resulting in a higher yield rate during welding. Furthermore, dividing the first flow cavity 13 into several isolated heat exchange cavities 14 increases the contact area between the phase change material and the fluid (flue gas) outside the heat exchange plate 11. This allows the phase change material to absorb heat from the flue gas more fully and transfer it to the fluid more efficiently, thereby improving heat exchange efficiency.

[0040] Furthermore, a second pipe 41 is connected to each heat exchange chamber 14, and the second pipe 41 is interconnected through the water collection tank 5 so that the heat exchange chambers 14 connected to the second pipe 41 are interconnected.

[0041] By adopting the aforementioned technical solution, since each heat exchange chamber 14 is interconnected through the second pipe 41 and the water collection tank 5, when the pressure in a heat exchange chamber 14 changes due to heat exchange, the fluid can flow between the heat exchange chambers 14 through the second pipe 41, thereby balancing the pressure in each heat exchange chamber 14 and preventing equipment damage or impact on heat exchange efficiency due to uneven pressure. Furthermore, since the heat exchange chambers 14 are isolated from each other, the heat exchange efficiency varies at different locations, resulting in different phase change rates of the phase change material. To ensure timely supply of phase change material to the heat exchange chambers 14, the second pipe 41 connecting the heat exchange chambers 14 is interconnected through the water collection tank 5, allowing the heat exchange chambers 14 with faster phase change rates to quickly replenish phase change material and balance the phase change material in each heat exchange chamber 14.

[0042] Furthermore, the tubular heat exchanger 2 is provided with a housing for fitting over the heat exchange tube 21, and the housing is provided with an interface 43 communicating with the heat exchange channel 23, and an air extraction device is detachably connected to the interface.

[0043] By adopting the aforementioned technical solution, reducing the gas pressure within the heat exchange channel 23 allows the phase change material to undergo a phase change at a lower boiling point. This enables the phase change material to absorb heat more quickly and transition from a liquid to a gaseous state at the same heat source temperature, accelerating the phase change process and thus improving the overall system's heat exchange efficiency. The gaseous phase change material can exchange heat with the fluid being heated more rapidly, resulting in more efficient heat transfer. Furthermore, since the heat exchange plates 11 of the plate heat exchanger 1 have multiple first flow chambers 13, multiple interfaces are required for simultaneous gas extraction. In contrast, only one interface 43 is needed on the tubular heat exchanger 2, which is more convenient than requiring multiple interfaces on the plate heat exchanger 1. Additionally, when extracting internal gas, the heat exchange channel 23 of the tubular heat exchanger 2 has a larger space than the first flow chamber 13 inside the plate heat exchanger 1, allowing for a higher extraction rate and preventing the rapid contraction of the plates during extraction in the plate heat exchanger 1. Preferably, the interface is equipped with a vacuum pump to maintain the vacuum level of the space where the phase change material is located, ensuring that the phase change material can undergo phase change at low temperature, and the phase change material can also be injected into it through the interface.

[0044] Furthermore, the heat exchange tube 21 inside the tubular heat exchanger 2 is a U-shaped heat exchange tube 21, and the two ends of the U-shaped heat exchange tube 21 are the water inlet 44 and the water outlet 45 of the tubular heat exchanger 2, respectively.

[0045] By adopting the aforementioned technical solution, the shape of the U-shaped heat exchange tube 21 allows for an increase in the length of the heat exchange tube 21 within a limited space, thereby increasing the heat exchange area and enhancing the heat exchange effect. Compared to the straight tube heat exchanger 2, the U-shaped heat exchange tube 21 can achieve more efficient heat exchange within the same equipment volume, making the structure of the tube heat exchanger 2 more compact and saving installation space.

[0046] Furthermore, the inlet 44 of the tubular heat exchanger 2 is located on the lower side, and the outlet 45 of the tubular heat exchanger 2 is located on the upper side of the tubular heat exchanger 2 opposite to the inlet 44. A baffle 24 is provided between the inlet 44 and the outlet 45 to extend the flow path of the fluid to be exchanged in the heat exchange tube 21.

[0047] Using the aforementioned technical solution, the inlet 44 is located on the lower side and the outlet 45 is located on the upper side. Because the gaseous phase change material within the heat exchange channel 23 exhibits a distribution with high-temperature gas at the top and low-temperature gas at the bottom, the fluid to be heat-exchanged first exchanges heat with the low-temperature phase change material when flowing in from the bottom, and then gradually exchanges heat with the high-temperature phase change material. This results in higher heat exchange efficiency. The presence of the baffle 24 not only extends the path of the fluid to be heat-exchanged but also promotes multiple turns and mixing of the fluid during flow. This mixing effect makes the temperature and composition inside the fluid to be heat-exchanged more uniform, avoiding excessive local differences and improving the overall heat exchange effect and product quality.

[0048] Preferably, the partition 24 can isolate the temperature on both sides, so that the higher temperature fluid flowing out of the second flow chamber 22 is not affected by the lower temperature fluid flowing in, and also allows the fluid to be exchanged to be at a relatively lower temperature, so that the heat exchange efficiency of the gaseous phase change material is higher.

[0049] Understandably, in another embodiment, the outlet 45 is located on the lower side and the inlet 44 is located on the upper side, so that when the fluid to be heat-exchanged flows in from the upper side, it first exchanges heat with the high-temperature phase change material, and can achieve a high heat exchange rate when it first enters.

[0050] Furthermore, the first pipe is divided into a first vertical pipe 32 connected to the upper end of the first flow chamber 13 and a first horizontal pipe 31 connected to the upper side of the heat exchange channel 23. Several first vertical pipes 32 are connected to the side wall of the first horizontal pipe 31.

[0051] By adopting the aforementioned technical solution, dividing the first pipeline into a first horizontal pipe 31 and multiple first vertical pipes 32, fewer pipes are used between the plate heat exchanger 1 and the tubular heat exchanger 2, saving materials and reducing the cost of the heat exchange system. The combined structure of the first pipeline into first vertical pipes 32 and first horizontal pipes 31 allows for more flexible and convenient installation. The length and angle of the first vertical pipes 32 and first horizontal pipes 31 can be adjusted according to the specific location and layout of the plate heat exchanger 1 and the tubular heat exchanger 2, resulting in smoother connections. In terms of maintenance, if a problem occurs in a section of the pipeline, it is easier to inspect, repair, or replace the first vertical pipe 32 or the first horizontal pipe 31 individually, reducing the difficulty and cost of maintenance.

[0052] Furthermore, the height of the first vertical pipe 32 is lower than the height of the connection between the first horizontal pipe 31 and the heat exchange channel 23.

[0053] Using the aforementioned technical solution, after the gaseous phase change material enters the first vertical pipe 32 from the first flow cavity 13, since the height of the first vertical pipe 32 is lower than the connection between the first horizontal pipe 31 and the heat exchange channel 23, gravity will cause the gaseous phase change material to flow more smoothly into the first horizontal pipe 31, and then into the heat exchange channel 23. This gravity-assisted flow method reduces the resistance of the gaseous phase change material in the pipe, ensuring the continuous and stable flow of the gaseous phase change material, and avoiding the problem of gaseous phase change material accumulation or poor flow caused by excessive resistance in the pipe.

[0054] Furthermore, the tubular heat exchanger 2 is equipped with a pressure gauge 6 for detecting the air pressure inside the heat exchange channel 23.

[0055] Using the aforementioned technical solution, pressure gauge 6 can accurately display the pressure value within the heat exchange channel 23 in real time. Operators can intuitively understand the current operating status of the system by observing the reading of pressure gauge 6. By monitoring the pressure, the risk of equipment damage caused by excessive pressure, such as pipe rupture or seal failure, can be effectively prevented.

[0056] In addition to the preferred embodiments described above, this application has other implementation methods. All other embodiments obtained by those skilled in the art based on the embodiments in this application without creative effort are within the scope of protection claimed in this application.

Claims

1. A vacuum heat exchange system, characterized by, The device includes a plate heat exchanger and a tubular heat exchanger. The plate heat exchanger contains multiple spaced heat exchange plates, which form a flue for circulating flue gas. Each heat exchange plate contains a first flow chamber containing a phase change material. The tubular heat exchanger contains multiple spaced heat exchange tubes, which form a heat exchange channel for the flow of the phase change material. Each heat exchange tube contains a second flow chamber for the flow of the fluid to be heat exchanged. The upper end of the first flow chamber is connected to the upper side of the heat exchange channel via a first pipe, and the lower side of the heat exchange channel is connected to the lower end of the first flow chamber via a return pipe.

2. The vacuum heat exchange system of claim 1, wherein The return pipe is divided into a second pipe and a third pipe. The lower end of the first flow chamber is connected to a water collection tank through the second pipe. The water collection tank is connected to the lower side of the heat exchange channel through the third pipe. The diameter of the third pipe is larger than that of the first pipe and the number of third pipes is less than that of the first pipe. The diameter of the third pipe is larger than that of the second pipe and the number of third pipes is less than that of the second pipe.

3. A vacuum heat exchange system according to claim 2, wherein The heat exchange plate is made of two thin plates welded together by a welding wire, so that the first flow cavity is divided into several mutually isolated heat exchange cavities by the welding wire.

4. The vacuum heat exchange system of claim 3, wherein, Each heat exchange chamber is connected to a second pipe, and the second pipes are interconnected through the water collection tank, so that the heat exchange chambers connected to the second pipes are interconnected.

5. The vacuum heat exchange system of claim 1, wherein, The tubular heat exchanger is provided with a shell for fitting over the heat exchange tubes. The shell is provided with an interface that communicates with the heat exchange channel, and an air extraction device is detachably connected to the interface.

6. The vacuum heat exchange system of claim 1, wherein, The inlet of the tubular heat exchanger is located on the lower side, and the outlet of the tubular heat exchanger is located on the upper side of the tubular heat exchanger opposite to the inlet. A baffle is provided between the inlet and the outlet to extend the flow path of the fluid to be exchanged in the heat exchange tube.

7. The vacuum heat exchange system of claim 1, wherein The heat exchange tubes inside the tubular heat exchanger are U-shaped heat exchange tubes, with the inlet and outlet of the tubular heat exchanger at each end.

8. The vacuum heat exchange system of claim 1, wherein, The first pipe is divided into a first vertical pipe connected to the upper end of the first flow chamber and a first horizontal pipe connected to the upper side of the heat exchange channel. Several first vertical pipes are connected to the side wall of the first horizontal pipe.

9. A vacuum heat exchange system according to claim 8, wherein The height of the first vertical pipe is lower than the height of the connection between the first horizontal pipe and the heat exchange channel.

10. The vacuum heat exchange system of claim 1, wherein, The tubular heat exchanger is equipped with a pressure gauge for detecting the air pressure inside the heat exchange channel.

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