Vacuum plate heat exchanger

Abstract

The invention discloses a vacuum plate heat exchanger, belongs to the field of heat exchange, overcomes the defect that a vacuum heat exchanger is prone to leakage, and is mainly characterized in that a heat exchange plate is correspondingly connected with at least one heat exchange tube, and the heat exchange plate is formed by welding two thin plates arranged front and back; a plurality of first flowing cavities which are arranged at intervals in the smoke flowing direction are arranged between the two thin plates, phase change materials are arranged in the first flowing cavities, a smoke channel is formed between every two adjacent heat exchange plates in the lower heat exchange cavity, fluid to be subjected to heat exchange is arranged between the heat exchange pipes in the upper heat exchange cavity, second flowing cavities are formed in the heat exchange pipes, and phase change materials are arranged in the second flowing cavities. The second flow cavities are communicated with the first flow cavities in the corresponding heat exchange plates through transition structures; the first flowing cavities in the same heat exchange plate communicate with one another, and / or the second flowing cavities in the heat exchange pipes on the single heat exchange plate communicate with one another. The heat exchange device is mainly used for solving the problems of dust accumulation of the heat exchange element on the smoke side and damage to the heat exchange element on the low-temperature side.

Description

Technical Field

[0001] The present application relates to the field of heat exchange, and in particular to a vacuum plate heat exchanger. Background Art

[0002] A vacuum heat exchanger is a heat exchange device that works in a vacuum environment. It is mainly used to achieve heat transfer between fluids of different temperatures. Its structure usually includes components such as a shell, a tube bundle, and a tube sheet. The shell ensures the internal vacuum environment. The tube bundle is the main place for heat exchange. The tube sheet is used to fix the tube bundle and separate different fluid areas. The working principle is to use the special thermophysical properties of the fluid in a vacuum state, such as a lower boiling point, to make it easier for the low-temperature fluid to evaporate and absorb heat in a vacuum environment. The high-temperature fluid transfers heat to the low-temperature fluid through the tube bundle to achieve effective heat transfer. The vacuum heat exchanger has many advantages, such as efficient evaporation at a lower temperature, which can reduce energy consumption. In addition, because it can effectively avoid problems such as material oxidation in a vacuum environment, it is suitable for heating or cooling heat-sensitive materials. It is widely used in chemical, pharmaceutical, food and other industries, and is one of the important equipment for improving production efficiency and product quality.

[0003] However, the vacuum heat exchanger in the prior art uses a heat exchange tube, which has a low heat exchange efficiency. In order to improve the heat exchange efficiency, a spiral protrusion is formed on the side wall of the heat exchange tube on the side with a higher temperature to increase the contact area and improve the heat exchange efficiency. When this type of heat exchanger is used to exchange high-temperature flue gas, the flue gas tends to accumulate dust on the leeward side of the heat exchange tube and on the spiral protrusion, resulting in a decrease in the heat exchange efficiency of the leeward side. In addition, because the temperature in the flue gas channel varies greatly and may contain water vapor, long-term use may even cause dust accumulation on the heat exchange tube to cause corrosion, greatly reducing the life of the heat exchange tube. When a whole heat exchange plate is used to exchange heat with low-temperature fluid and flue gas respectively, the welding quality of the welding rings is often unstable due to the large number of welding rings of the heat exchange plate. When the fluid on the low-temperature side is unstable, the welding ring on the low-temperature side will be damaged and leaks will appear. At this time, the heat exchange plate will leak the lower temperature fluid into the flue during operation, causing a large amount of low-temperature fluid to flow into the flue, causing the entire heat exchanger to paralyze. Summary of the invention

[0004] In order to overcome the defect of easy leakage of vacuum heat exchangers in the prior art, the present application provides a vacuum plate heat exchanger, which can solve the problem of dust accumulation on the heat exchange element on the flue gas side and avoid damage to the heat exchange element on the low temperature side.

[0005] In order to achieve the above-mentioned purpose, the present application adopts the following technical scheme: a vacuum plate heat exchanger, comprising an upper heat exchange chamber and a lower heat exchange chamber isolated from each other, and a plurality of heat exchange tubes whose main body is located in the upper heat exchange chamber and a plurality of heat exchange plates whose main body is located in the lower heat exchange chamber and arranged in a front-to-back manner, wherein one heat exchange plate is connected to at least one heat exchange tube, the heat exchange plate is welded by two thin plates arranged in a front-to-back manner, a plurality of first flow chambers arranged in a spaced manner along the flue gas flow direction are arranged between the two thin plates, a phase change material is arranged in the first flow chamber, a flue gas channel is provided between two adjacent heat exchange plates in the lower heat exchange chamber, a fluid to be heat exchanged is provided between the heat exchange tubes in the upper heat exchange chamber, a second flow chamber is provided in the heat exchange tube, and the second flow chamber is connected to the first flow chamber in the corresponding heat exchange plate through a transition structure; the first flow chambers in the same heat exchange plate are connected to each other and / or the second flow chambers in the heat exchange tubes on a single heat exchange plate are connected to each other.

[0006] After adopting the above technical solution, the present application has the following advantages: in terms of structural design, the heat exchange tubes that do not require welding are placed in the upper heat exchange cavity, which greatly improves the reliability of the equipment, reduces the risk of damage, and effectively prevents the low-temperature fluid from entering the heat exchange tubes and then entering the lower heat exchange cavity; at the same time, a heat exchange plate is used on the flue gas side to reduce the leeward area, reduce the degree of ash accumulation, and ensure stable heat exchange efficiency. In terms of heat exchange method, a phase change material is placed in the first flow cavity of the heat exchange plate, and through phase change, it changes from liquid to gas, and transfers heat to the heat exchange tube of the upper heat exchange cavity. The gaseous phase change material then transfers the temperature to the low-temperature fluid, achieving efficient heat exchange, and the phase change material becomes liquid again and falls into the heat exchange plate. In addition, since the second flow cavity is isolated from the low-temperature fluid, even if the welding strength of the heat exchange plate is low and a leak occurs, only the phase change material will leak out, and the low-temperature fluid will not leak, thereby minimizing equipment losses and extending the service life of the equipment. Furthermore, by designing the first flow chambers in the same heat exchange plate to be interconnected and / or the second flow chambers that are connected to the first flow chambers on the same heat exchange plate to be interconnected, the complexity of injecting phase change materials into the heat exchange tubes or reducing the air pressure is solved. The prior art is to connect the phase change materials or the air pumps to the heat exchange tubes respectively and then inject the phase change materials or reduce the air pressure, which effectively increases the work efficiency.

[0007] Furthermore, a connecting portion for connecting two adjacent first flow chambers is provided between the first flow chambers.

[0008] By adopting the above-mentioned technical solution, the connecting part can make each first flow chamber interconnected, and when reducing the gas pressure and injecting the phase change material, it can be done together as a plate unit, which improves the work efficiency. Since the connecting part is an external structure, the heat exchange tube needs to be welded when it is added to the heat exchange tube. Compared with setting it in the second flow chamber, the loss to the entire heat exchanger when the connecting part is damaged is smaller when the connecting part is set at the first flow chamber. Although the degree of damage to the heat exchange plate is increased, it is much smaller than the loss caused by the damage to the heat exchange tube. Moreover, the connection part is set at the first flow chamber to enhance the fault tolerance of the system to a certain extent. If a first flow chamber has problems such as local blockage or poor flow of phase change material, the connecting part can provide an additional flow path so that the phase change material can continue to circulate through other channels, reducing the possibility of performance degradation or failure of the entire heat exchange system due to local failures, and improving the reliability and stability of the entire heat exchange system.

[0009] Furthermore, the connecting portion is located above the liquid surface of the liquid phase change material.

[0010] With the above-mentioned technical solution, since the position of the connecting part will increase the risk of leakage compared to the original structure, setting the connecting part at a position above the liquid level can reduce the risk of liquid phase change material leaking to other chambers through the connecting part. Even if leakage occurs, the gaseous accompanying material will leak first, and the loss caused by the gaseous phase change material entering the flue gas channel is much smaller than the impact caused by the liquid phase change material. In addition, during the circulation and heat transfer of the gaseous phase change material, the pressure balance in the system is very important. The connecting part is located above the liquid level, which is more conducive to the pressure balance of the gaseous phase change material between adjacent chambers. The gaseous phase change material can quickly flow from the chamber with higher pressure to the chamber with lower pressure through the connecting part, making the pressure distribution of the entire system more uniform, avoiding problems such as poor flow of the phase change material or unstable system operation due to pressure imbalance.

[0011] Furthermore, the heat exchange plate further comprises a welding portion and the connecting portion provided between two adjacent first flow cavities, and the welding portion separates the first flow cavities on both sides.

[0012] Adopting the above technical solution, in the improvement here, the connecting part is a channel surrounded by the unwelded part and the thin plates far away from each other on the front and rear sides, and the channel is connected with the first flow chambers on the adjacent two sides, so that the original heat exchange plate can achieve the purpose of mutual connection between the first flow chambers through a small change, which greatly reduces the workload and material cost, and the connecting part and the heat exchange plate adopt a similar construction method, so that the connecting part and the heat exchange plate have better adaptability and integrity in structure. This design helps the entire heat exchanger to be more regular in appearance and internal structure, facilitates installation, maintenance and coordination with other components, and optimizes the overall performance of the heat exchanger.

[0013] Furthermore, the height of the connecting portion gradually decreases along the flow direction of the smoke.

[0014] By adopting the above-mentioned technical solution, the temperature of the flue gas will change during the flow process, and the temperature will gradually decrease along the flow direction. Therefore, the liquid level of the liquid phase change material in the first flow chambers that are interconnected is often higher along the flow direction of the flue gas. Therefore, the height of the connecting part is gradually reduced along the flow direction of the flue gas, which can make it easier for the liquid phase change material to be distributed to other first flow chambers, ensuring that there is sufficient phase change material in other first flow chambers, thereby improving the heat exchange efficiency in the heat exchange plate.

[0015] Furthermore, the heat exchange tube or heat exchange plate is provided with a valve communicating with the outside and used for connecting to a vacuum pumping device.

[0016] By adopting the above-mentioned technical solution, the air and other gases inside the heat exchange tube or heat exchange plate can be extracted by connecting the vacuum equipment through the valve, thereby creating a vacuum or low-pressure environment. This is the basic condition for the normal operation of the vacuum heat exchanger, which is conducive to utilizing the special thermophysical properties of the fluid under the vacuum state, such as allowing the low-temperature fluid to evaporate and absorb heat at a lower temperature, thereby improving the heat transfer efficiency. In addition, when the equipment is repaired, the relevant detection equipment can be connected through the valve to perform pressure detection, leakage detection and other operations on the inside of the heat exchange tube or heat exchange plate, so as to quickly and accurately determine whether the equipment has faults or hidden dangers. For example, after vacuuming, close the valve and observe the changes in system pressure to determine whether there are leaks, so as to facilitate timely discovery and repair of problems and ensure the safe and stable operation of the equipment.

[0017] Furthermore, a single heat exchange plate and the heat exchange tubes connected thereto form a single set of heat exchange modules, and the valves between two adjacent heat exchange modules are connected via a vacuum tube, and the vacuum tube is provided with a valve port for connecting to a vacuum pumping device.

[0018] By adopting the above-mentioned technical solution, the valves of adjacent heat exchange modules are connected through vacuum tubes, and valve ports are set on the vacuum tubes to connect to vacuum equipment, so that multiple heat exchange modules can be centrally vacuumed. Compared with connecting the valves of each heat exchange tube or heat exchange plate to vacuum equipment separately, this method greatly simplifies the piping layout of the vacuum system, improves the efficiency of the vacuum operation, and can more quickly make the entire heat exchanger reach the required vacuum environment. And by vacuuming through a common vacuum tube, the consistency of the vacuum degree between each heat exchange module can be better guaranteed.

[0019] Furthermore, the vacuum tube is detachably connected to the valve.

[0020] With the above technical solution, when a heat exchange module fails or needs to be maintained separately, since the vacuum tube and valve are detachable, the connection between the module valve and the vacuum tube can be easily disconnected to completely isolate it. In addition, the vacuum tube can be removed while the heat exchanger is working, so as to avoid the vacuum tube working in an alternating high and low temperature environment and increase the service life of the vacuum tube.

[0021] Furthermore, the valve is arranged on the top of the heat exchange tube.

[0022] With the above technical solution, during the vacuuming process, air and other gases will naturally gather upwards. The valve is set at the top of the heat exchange tube, so that the gas can be discharged from the top more conveniently, accelerating the vacuuming process, and helping to quickly create a vacuum environment in the heat exchange tube, thereby giving full play to the efficient heat exchange performance of the vacuum heat exchanger under vacuum. If the valve is set in other positions, especially near the bottom, during the vacuuming process, the residual liquid in the heat exchange tube may hinder the discharge of gas, and may even enter the valve and connecting pipes, affecting the vacuuming effect and the normal operation of the valve.

[0023] Furthermore, each first flow cavity in the heat exchange plate is correspondingly connected to a second flow cavity in a heat exchange tube.

[0024] With the above technical solution, each first flow cavity is connected to a corresponding second flow cavity, making the heat transfer path more direct and accurate. After the phase change material undergoes phase change in the first flow cavity and absorbs heat, it can be quickly and efficiently transferred to the second flow cavity connected to it, and heat exchange is carried out with the low-temperature fluid in the heat exchange tube, reducing the loss and dispersion of heat during the transfer process, and improving the efficiency and speed of heat transfer. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present application is further described below in conjunction with the accompanying drawings: Figure 1 A schematic diagram of a vacuum plate heat exchanger for this application; Figure 2 for Figure 1 AA section view; Figure 3 It is a schematic diagram of the heat exchange plate; Figure 4 It is a schematic diagram of a vacuum plate heat exchanger viewed from the left.

[0026] Description of the drawings: 1. Upper heat exchange chamber; 11. Water inlet; 12. Water outlet; 13. Partition; 2. Lower heat exchange chamber; 3. Heat exchange tube; 31. Second flow chamber; 4. Heat exchange plate; 41. First flow chamber; 42. Flue gas channel; 5. Transition structure; 6. Connecting part; 7. Valve; 8. Vacuum tube; 81. Valve port. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments.

[0028] The terms "first", "second", etc. (if any) in the specification and claims of this application are used to distinguish similar objects, rather than to describe a specific order or sequence. Even if "second" is used to distinguish before a certain technical feature, it does not necessarily indicate that it has "first". It should be understood that in this application, "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. It should be understood that in this application, "multiple" refers to two or more. "And / or" is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, X and / or Y can represent: X exists alone, X and Y exist at the same time, and Y exists alone. The character " / " generally indicates that the related objects before and after are in an "or" relationship. "Contains X, Y and Z", "Contains X, Y, Z" means that X, Y, and Z are all included, "Contains X, Y or Z" means that one of X, Y, and Z is included, and "Contains X, Y and / or Z" means that any one, any two, or three of X, Y, and Z are included.

[0029] The following specific embodiments are used to describe the technical solution of the present application in detail. The following specific embodiments can be combined or replaced with each other according to actual conditions, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0030] like Figures 1 to 4 As shown, the present application provides a vacuum plate heat exchanger, comprising an upper heat exchange chamber 1 and a lower heat exchange chamber 2 isolated from each other, and a plurality of heat exchange tubes 3 whose main body is located in the upper heat exchange chamber 1 and a plurality of heat exchange plates 4 whose main body is located in the lower heat exchange chamber 2 and arranged at intervals in front and back, one heat exchange plate 4 is correspondingly connected to at least one heat exchange tube 3, the heat exchange plate 4 is welded by two thin plates arranged in front and back, and a plurality of first flow chambers 41 arranged at intervals along the flue gas flow direction are provided between the two thin plates, and a phase change material is provided in the first flow chamber 41, a flue gas channel is provided between two adjacent heat exchange plates 4 in the lower heat exchange chamber 2, and a fluid to be heat exchanged is provided between the heat exchange tubes 3 in the upper heat exchange chamber 1, a second flow chamber 31 is provided in the heat exchange tube 3, and the second flow chamber 31 is connected to the first flow chamber 41 in the corresponding heat exchange plate 4 through a transition structure 5; the first flow chambers 41 in the same heat exchange plate 4 are connected to each other.

[0031] After adopting the above technical solution, the present application has the following advantages: in terms of structural design, the heat exchange tube 3 that does not require welding is placed in the upper heat exchange chamber 1, which greatly improves the reliability of the equipment, reduces the risk of damage, and effectively prevents the low-temperature fluid from entering the heat exchange tube 3 and then entering the lower heat exchange chamber 2; at the same time, a heat exchange plate 4 is used on the flue gas side to reduce the leeward area, reduce the degree of ash accumulation, and ensure stable heat exchange efficiency. In terms of heat exchange mode, a phase change material is placed in the first flow chamber 41 of the heat exchange plate 4, which changes from liquid to gas through phase change, and transfers heat to the heat exchange tube 3 of the upper heat exchange chamber 1. The gaseous phase change material then transfers the temperature to the low-temperature fluid, achieving efficient heat exchange, and the phase change material becomes liquid again and falls into the heat exchange plate 4. In addition, since the second flow chamber 31 is isolated from the low-temperature fluid, even if the welding strength of the heat exchange plate 4 is low and leaks, only the phase change material will leak out, and the low-temperature fluid will not leak, which minimizes equipment losses and extends the service life of the equipment. Furthermore, by designing the first flow chambers 41 in the same heat exchange plate 4 to be interconnected, the complexity of injecting phase change materials or reducing air pressure in the heat exchange tube 3 is solved. The prior art is to connect the phase change materials or the air pumps to the heat exchange tubes 3 one by one and then inject the phase change materials or reduce the air pressure, which effectively increases the work efficiency.

[0032] Specifically, the heat exchange tube can be processed without welds by drawing or extrusion process. The transition structure 5 is an intermediate pipe. The part where the transition structure 5 is connected to the heat exchange tube is a circular pipe. The part where the transition structure 5 is connected to the heat exchange plate is an elliptical pipe. The heat exchange tube 3 can partially enter the lower heat exchange chamber 2, but the heat exchange plate 4 cannot partially enter the upper heat exchange chamber 1, ensuring that the damage of the heat exchange plate 4 will not allow the low-temperature fluid in the upper heat exchange chamber 1 to enter the two flow chambers. The unwelded parts of the heat exchange plate 4 are far away from each other, which means that the two thin plates are far away from each other, so that the space surrounded by the two thin plates becomes the first flow chamber 41. The phase change material can be converted between solid, gaseous and liquid states, so that the temperature of the lower heat exchange chamber 2 is brought to the upper heat exchange chamber 1 through the state change of the phase change material.

[0033] It is understandable that the upper heat exchange chamber 1 and the lower heat exchange chamber 2 may also have a certain inclination with the plumb line, but cannot be completely horizontal, which will cause the gaseous phase change material to be unable to flow into the second flow chamber 31 in the upper heat exchange chamber 1.

[0034] Furthermore, the heat exchange plate 4 further includes a welding portion and the connecting portion 6 provided between two adjacent first flow chambers 41 , the welding portion separates the first flow chambers 41 on both sides, and the connecting portion 6 is used to connect the two adjacent first flow chambers 41 .

[0035] By adopting the above technical solution, the connecting part 6 can make each first flow chamber 41 interconnected, and when reducing the gas pressure and injecting the phase change material, it can be done together as a plate unit, which improves the work efficiency. Since the connecting part 6 is an external structure, it is necessary to weld the heat exchange tube 3 when it is added to the heat exchange tube 3. Compared with setting the connecting part 6 at the first flow chamber 41, the loss of the entire heat exchanger when the connecting part 6 is damaged is smaller than that when it is set at the second flow chamber 31. Although the degree of damage at the heat exchange plate 4 is increased, it is much smaller than the loss caused by the damage of the heat exchange tube 3. Moreover, the connection part 6 is set at the first flow chamber 41, which enhances the fault tolerance of the system to a certain extent. If a first flow cavity 41 is partially blocked or the phase change material does not flow smoothly, the connecting portion 6 can provide an additional flow path so that the phase change material can continue to circulate through other channels, reducing the possibility of performance degradation or failure of the entire heat exchange system due to local failures, and improving the reliability and stability of the entire heat exchanger system. The connecting portion 6 is a channel surrounded by the unwelded part and the thin plates on the front and rear sides that are far away from each other, and the channel is connected to the first flow cavities 41 on the adjacent sides, so that the original heat exchange plate 4 can achieve the purpose of interconnection between the first flow cavities 41 with a small amount of changes, greatly reducing the workload and material costs, and the connecting portion 6 and the heat exchange plate 4 adopt a similar construction method, so that the connecting portion 6 and the heat exchange plate 4 have better adaptability and integrity in structure. This design helps the entire heat exchanger to be more regular in appearance and internal structure, facilitates installation, maintenance and coordination with other components, and optimizes the overall performance of the heat exchanger.

[0036] It can be understood that in other embodiments, the second flow chambers 31 in the same heat exchange plate 4 are interconnected, so that the air inside the same heat exchange plate can be completely extracted through only one interface to achieve the effect of reducing the air pressure.

[0037] It can be understood that in other embodiments, the first flow chambers 41 in the same heat exchange plate 4 are interconnected, and the second flow chambers 31 connected to the first flow chamber 41 on the same heat exchange plate 4 are also interconnected, so that the air inside the same heat exchange plate can be completely extracted through only one interface to achieve the effect of reducing the air pressure.

[0038] Further, such as Figure 3 As shown, the height of the connecting portion 6 gradually decreases along the flow direction of the flue gas.

[0039] By adopting the above-mentioned technical solution, the temperature of the flue gas will change during the flow process, and the temperature will gradually decrease along the flow direction. Therefore, the first flow chambers 41 that are interconnected often have a higher liquid level of the liquid phase change material along the flow direction of the flue gas. Therefore, gradually reducing the height of the connecting part 6 along the flow direction of the flue gas can make it easier for the liquid phase change material to be distributed to other first flow chambers 41, ensuring that there is sufficient phase change material in other first flow chambers 41, thereby improving the heat exchange efficiency in the heat exchange plate 4.

[0040] Furthermore, the connecting portion 6 is located above the liquid surface of the liquid phase change material.

[0041] With the above-mentioned technical solution, since the position of the connecting portion 6 will increase the risk of leakage compared to the original structure, setting the connecting portion 6 at the position of the connecting portion 6 above the liquid level can reduce the risk of liquid phase change material leaking to other chambers through the connecting portion 6. Even if leakage occurs, the gaseous accompanying material will leak first, and the loss caused by the gaseous phase change material entering the flue gas channel 42 is much smaller than the impact caused by the liquid phase change material. In addition, during the circulation and heat transfer of the gaseous phase change material, the pressure balance in the system is very important. The connecting portion 6 is located above the liquid level, which is more conducive to the pressure balance of the gaseous phase change material between adjacent chambers. The gaseous phase change material can quickly flow from the chamber with higher pressure to the chamber with lower pressure through the connecting portion 6, making the pressure distribution of the entire system more uniform, avoiding problems such as poor flow of the phase change material or unstable system operation due to pressure imbalance.

[0042] Further, such as Figures 1 to 3 As shown, the heat exchange plate 4 is provided with a valve 7 communicating with the outside and used for connecting to a vacuum pumping device.

[0043] By connecting the vacuum equipment through the valve 7, the air and other gases inside the heat exchange plate 4 can be extracted, thereby creating a vacuum or low-pressure environment. This is the basic condition for the normal operation of the vacuum heat exchanger, which is conducive to utilizing the special thermophysical properties of the fluid under the vacuum state, such as allowing the low-temperature fluid to evaporate and absorb heat at a lower temperature, thereby improving the heat transfer efficiency. In addition, when the equipment is repaired, the relevant detection equipment can be connected through the valve 7 to perform pressure detection, leakage detection and other operations on the inside of the heat exchange plate 4, so as to quickly and accurately determine whether the equipment has faults or hidden dangers. For example, after vacuuming, close the valve 7 and observe the changes in the system pressure to determine whether there are leaks, so as to facilitate timely discovery and repair of problems and ensure the safe and stable operation of the equipment.

[0044] Furthermore, each first flow cavity 41 in the heat exchange plate 4 is correspondingly connected to a second flow cavity 31 in the heat exchange tube 3 .

[0045] By adopting the above technical solution, each first flow cavity 41 is connected to a corresponding second flow cavity 31, making the heat transfer path more direct and accurate. After the phase change material undergoes phase change in the first flow cavity 41 and absorbs heat, it can be quickly and efficiently transferred to the second flow cavity 31 connected thereto, and heat exchange is performed with the low-temperature fluid in the heat exchange tube 3, reducing the loss and dispersion of heat during the transfer process, and improving the efficiency and speed of heat transfer.

[0046] In another embodiment, Figure 4 As shown, the heat exchange tube 3 is provided with a valve 7 communicating with the outside world for connecting to a vacuum pumping device. Further, the valve 7 and the connecting portion 6 are arranged at the top of the heat exchange tube 3 .

[0047] By adopting the above technical solution, the air and other gases inside the heat exchange tube 3 can be extracted by connecting the vacuum equipment through the valve 7, thereby creating a vacuum or low pressure environment. This is the basic condition for the normal operation of the vacuum heat exchanger, which is conducive to utilizing the special thermophysical properties of the fluid under the vacuum state, such as allowing the low-temperature fluid to evaporate and absorb heat at a lower temperature, thereby improving the heat transfer efficiency. In addition, during equipment maintenance, the valve 7 can be connected to the relevant detection equipment to perform pressure detection, leakage detection and other operations on the inside of the heat exchange tube 3, so as to quickly and accurately determine whether the equipment has faults or hidden dangers. For example, after vacuuming, the valve 7 is closed and the system pressure changes are observed to determine whether there are leakage points, which is convenient for timely discovery and repair of problems and ensuring the safe and stable operation of the equipment. The valve 7 and the connecting part 6 are arranged at the top of the heat exchange tube 3. During the vacuuming process, air and other gases will naturally gather at a high place. The valve 7 is arranged at the top of the heat exchange tube 3, so that the gas can be discharged from the top more conveniently, accelerating the vacuuming process, and helping to quickly create a vacuum environment in the heat exchange tube 3, thereby giving full play to the efficient heat exchange performance of the vacuum heat exchanger under the vacuum state. If the valve 7 is set at other positions, especially near the bottom, during the vacuuming process, the residual liquid in the heat exchange tube 3 may hinder the discharge of gas and may even enter the valve 7 and the connecting pipeline, affecting the vacuuming effect and the normal operation of the valve 7.

[0048] Furthermore, a single heat exchange plate 4 and the heat exchange tube 3 connected thereto form a single set of heat exchange modules, and the valves 7 between two adjacent heat exchange modules are connected via a vacuum tube 8, and the vacuum tube 8 is provided with a valve port 81 for connecting to a vacuum pumping device.

[0049] By adopting the above-mentioned technical solution, the valves 7 of adjacent heat exchange modules are connected through vacuum tubes 8, and valve ports 81 are provided on the vacuum tubes 8 to connect to the vacuum pumping equipment, so that a centralized vacuum pumping operation can be performed on multiple heat exchange modules. Compared with connecting the valve 7 of each heat exchange plate 4 to the vacuum pumping equipment separately, this method greatly simplifies the piping layout of the vacuum pumping system, improves the efficiency of the vacuum pumping operation, and can more quickly achieve the required vacuum environment inside the entire heat exchanger. And by vacuuming through the shared vacuum tube 8, the consistency of the vacuum degree between each heat exchange module can be better guaranteed.

[0050] Furthermore, the vacuum tube 8 is detachably connected to the valve 7 .

[0051] By adopting the above technical solution, when a heat exchange module fails or needs to be maintained separately, since the vacuum tube 8 and the valve 7 are detachable, the connection between the valve 7 and the vacuum tube 8 of the module can be easily disconnected to completely isolate it. In addition, the vacuum tube 8 can be removed when the heat exchanger is working, so as to avoid the vacuum tube 8 working in an alternating high and low temperature environment and increase the service life of the vacuum tube 8.

[0052] like Figure 1 and Figure 4 As shown, a water inlet 11 and a water outlet 12 are provided on the top surface of the upper heat exchange chamber 1, wherein the water inlet 11 is located downstream of the flue gas flow, and the water outlet 12 is located upstream of the flue gas flow, and mutually staggered partitions 13 are also provided in the upper heat exchange chamber 1. Under the guidance of the partition 13, the fluid entering through the water inlet 11 can more fully fill the entire upper heat exchange chamber 1, and extend the flow path, so that the heat exchange tube 3 is in full contact with the fluid in the upper heat exchange chamber 1 to exchange heat. Since the downstream temperature of the flue gas flow is relatively low, the fluid flowing into the water inlet 11 indirectly exchanges heat with it, so that the temperature difference can be relatively small, and there will be no drastic temperature difference reaction, thereby protecting the life and safety of the equipment. The water outlet 12 is arranged upstream of the flue gas flow, so that the fluid with relatively increased temperature can indirectly exchange heat with the flue gas that has just entered the heat exchanger, so that the temperature difference between the two can also be relatively reduced, thereby protecting the safety of the equipment.

[0053] In addition to the above-mentioned preferred embodiments, the present application also has other implementation modes. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making any creative work are within the scope of protection requested by the present application.

Claims

1. A vacuum plate heat exchanger, characterized in that: It comprises an upper heat exchange chamber and a lower heat exchange chamber which are isolated from each other, a plurality of heat exchange tubes whose main body is located in the upper heat exchange chamber, and a plurality of heat exchange plates whose main body is located in the lower heat exchange chamber and are arranged in a front-to-back interval. One heat exchange plate is connected to at least one heat exchange tube. The heat exchange plate is welded by two thin plates arranged in a front-to-back manner. A plurality of first flow chambers which are arranged in a spaced manner along the flow direction of the flue gas are arranged between the two thin plates. Phase change material is arranged in the first flow chamber. A flue gas channel is provided between two adjacent heat exchange plates in the lower heat exchange chamber. The fluid to be heat exchanged is provided between the heat exchange tubes in the upper heat exchange chamber. A second flow chamber is provided in the heat exchange tube, and the second flow chamber is connected to the first flow chamber in the corresponding heat exchange plate through a transition structure. The first flow chambers in the same heat exchange plate are connected to each other and / or the second flow chambers in the heat exchange tubes on a single heat exchange plate are connected to each other.

2. A vacuum plate heat exchanger according to claim 1, characterized in that: A connecting portion for connecting two adjacent first flow chambers is provided between the first flow chambers.

3. The vacuum plate heat exchanger according to claim 2, characterized in that: The connecting portion is located above the liquid surface of the liquid phase change material.

4. The vacuum plate heat exchanger according to claim 2, characterized in that: The heat exchange plate further includes a welding portion and the connecting portion provided between two adjacent first flow chambers, and the welding portion separates the first flow chambers on both sides.

5. The vacuum plate heat exchanger according to claim 4, characterized in that: The height of the connecting portion gradually decreases along the flow direction of the smoke.

6. The vacuum plate heat exchanger according to claim 1, characterized in that: The heat exchange tube or heat exchange plate is provided with a valve communicating with the outside world and used for connecting to a vacuum pumping device.

7. The vacuum plate heat exchanger according to claim 6, characterized in that: A single heat exchange plate and the heat exchange tubes connected thereto form a single group of heat exchange modules. The valves between two adjacent heat exchange modules are connected via a vacuum tube. The vacuum tube is provided with a valve port for connecting to a vacuum pumping device.

8. The vacuum plate heat exchanger according to claim 7, characterized in that: The vacuum tube is detachably connected to the valve.

9. The vacuum plate heat exchanger according to claim 7, characterized in that: The valve is arranged on the top of the heat exchange tube.

10. The vacuum plate heat exchanger according to claim 1, characterized in that: Each first flow cavity in the heat exchange plate is correspondingly connected to a second flow cavity in a heat exchange tube.

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