Plate-type vacuum heat exchanger

Abstract

The utility model discloses a plate type vacuum heat exchanger belongs to heat exchange field, solved the problem of poor heat transfer performance in prior art, including upper heat exchange cavity and lower heat exchange cavity, upper heat exchange cavity and lower heat exchange cavity all are equipped with the heat exchange plate of interval setting, and each heat exchange plate is by two thin plates and is fixed by a plurality of welding parts, and the non -welding area of two thin plates forms flowing cavity, and is equipped with phase change material in flowing cavity, and the heat exchange plate between two adjacent heat exchange plates in lower heat exchange cavity is flue gas channel, and the heat exchange plate between two adjacent heat exchange plates in upper heat exchange cavity is the fluid channel of waiting for heat exchange, and the flowing cavity of upper heat exchange cavity is communicated with the flowing cavity of lower heat exchange cavity, and a plurality of welding parts are linear equidistance arrangement along the transverse and longitudinal heat exchange plate, and the welding part of transverse is mutually aligned, and the welding part of longitudinal is mutually aligned, and the welding part of adjacent along transverse and longitudinal all enclose and form the flowing cavity of linear through -going. The utility model improves heat transfer performance.

Description

Technical Field

[0001] This utility model relates to the field of heat exchange, and in particular to a plate vacuum heat exchanger. Background Technology

[0002] A vacuum heat exchanger is a heat exchange device that operates in a vacuum environment, primarily used to achieve heat exchange between fluids at different temperatures. Currently, some plate-type vacuum heat exchangers on the market mainly rely on the heat absorption and release morphology changes of phase change materials to achieve heat storage and release, thus realizing heat exchange between media. For example, the existing technology CN119934870A discloses a heat exchange device where the cavity is divided into mutually isolated upper and lower heat exchange chambers. The upper chamber houses heat exchange tubes, and the lower chamber houses heat exchange plates, which are connected one-to-one. A segmented first flow chamber containing phase change material is set between the thin plates of the heat exchange plates, and a second flow chamber is set inside the heat exchange tubes. The two types of flow channels are connected by a transition structure. The lower chamber plates serve as a flue gas passage, while the upper chamber tubes facilitate the flow of the fluid to be heat exchanged. However, the structures and mechanical properties of the two types of heat exchange carriers, the upper tubes and the lower plates, are inconsistent, resulting in poor overall equipment integrity. The phase change material undergoes asynchronous morphological changes and heat absorption / release in the lower tube plate, and the transition flow channels between the tubes and plates have numerous bends, leading to high resistance to medium flow and poor overall heat exchange uniformity and efficiency.

[0003] Furthermore, the existing technology CN223449030U also uses double thin plates welded together and internally replaces the heat exchange medium. It relies on the medium to cooperate with the plate to complete the heat exchange. However, its welded parts are arranged in a wavy and misaligned manner, which causes the internal flow channels to spontaneously narrow and bend, causing the heat exchange medium to frequently change direction. There are many dead corners where the heat exchange medium is stuck, which reduces the flow performance of the heat exchange medium and affects the heat exchange performance. Utility Model Content

[0004] The purpose of this invention is to provide a plate vacuum heat exchanger that solves the problem of poor heat exchange performance in the prior art and improves heat exchange performance.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a plate vacuum heat exchanger, comprising an upper heat exchange chamber and a lower heat exchange chamber, wherein both the upper and lower heat exchange chambers are provided with heat exchange plates spaced apart, each heat exchange plate being fixed by welding two thin plates through multiple welding parts, the non-welded areas of the two thin plates forming a flow cavity, and a phase change material being provided in the flow cavity, the space between two adjacent heat exchange plates in the lower heat exchange chamber being a flue gas channel, the space between two adjacent heat exchange plates in the upper heat exchange chamber being a channel for the fluid to be heat exchanged, the flow cavity of the upper heat exchange chamber being connected to the flow cavity of the lower heat exchange chamber, and the multiple welding parts being arranged equidistantly in a straight line along the transverse and longitudinal directions of the heat exchange plates, the transverse welding parts being aligned with each other, the longitudinal welding parts being aligned with each other, and the adjacent welding parts along the transverse and longitudinal directions forming a straight through flow cavity.

[0006] After adopting the above technical solution, this utility model has the following advantages: During heat exchange, the high-temperature flue gas in the flue gas channel of the lower heat exchange chamber heats the liquid phase change material inside the flow chamber through the thin plate. The liquid phase change material absorbs heat and vaporizes into a gaseous state. Through the neat arrangement of the welded parts, the flow chamber is a straight through structure without bends, turning points, local narrowing, or structural interruptions. This can minimize the upward flow resistance of the gaseous phase change material, allowing it to rise more quickly along the flow chamber and reducing stagnation. After the high-temperature gaseous phase change material enters the flow chamber of the upper heat exchange chamber, it transfers heat to the low-temperature fluid to be exchanged. After releasing heat, the liquid phase change material condenses and liquefies, then falls back into the flow chamber under gravity. The straight, continuous flow chamber minimizes backflow obstruction, further accelerating the overall circulation rate of the phase change material and improving heat exchange performance. At the same time, the neatly arranged welded parts more evenly limit the thin plate, minimizing deformation and compression of the flow chamber. In addition, both the upper and lower heat exchange chambers use heat exchange plates, making the vaporization, heat transfer, condensation, and backflow of the phase change material in both chambers more synchronized and the heat exchange material more evenly distributed. This effectively improves the heat transfer efficiency of the phase change material and the heat exchange uniformity of the entire machine, ensuring continuous, efficient, and stable operation of the gas-liquid phase change heat exchange.

[0007] Furthermore, the plurality of the welded portions are arranged in a rectangular array.

[0008] By adopting the aforementioned technical solution, the cavity contour of the flow cavity is made more consistent, which can make the gaseous and liquid phase change materials in the flow cavity more uniformly distributed, and the phase change materials in each area of ​​the heat exchange plate undergo phase change under heat and the cross-cavity flow conditions are more consistent, resulting in more uniform heat exchange.

[0009] Furthermore, the spacing between the transverse welded portions of the heat exchange plate is the same as the spacing between the longitudinal welded portions.

[0010] By adopting the aforementioned technical solution, the differences in lateral and longitudinal flow resistance can be eliminated as much as possible, and the problems of local flow lag and uneven phase change rate of phase change material can be avoided as much as possible. This allows the heat absorption and release and gas-liquid conversion of phase change material in the plate to be more synchronized, thereby further improving the heat uniformity of the heat exchange plate.

[0011] Furthermore, the welded sections arranged laterally and longitudinally on the heat exchange plate are all formed by intermittent welding.

[0012] By adopting the aforementioned technical solution, the inner wall of the flow cavity is smoother and more even, which further reduces the frictional resistance of the gaseous phase change material flowing upward and the liquid phase change material flowing back by gravity, resulting in a more stable two-phase flow of the phase change material.

[0013] Furthermore, the transverse and longitudinal cross-sections of the flow cavity are the same.

[0014] By adopting the aforementioned technical solution, the gas-liquid two-phase flow pattern and flow rate of the phase change material are more constant throughout the process, minimizing the need to overcome additional flow losses caused by abrupt changes in cross-section, and ensuring uniform circulation of the phase change material as much as possible.

[0015] Furthermore, the flow chambers in the upper heat exchange chamber and the lower heat exchange chamber are arranged in the same direction.

[0016] Through the above technical solution, the flow cavity is smoothly connected without misalignment or flow direction bends, which can further reduce the overall flow resistance of the gaseous phase change material being transported upward and the liquid phase change material being transported downward by gravity, weaken the flow loss caused by the misalignment of the flow cavity, and make the gas-liquid two-phase circulation flow of the phase change material smoother.

[0017] Furthermore, the multiple welded portions have the same shape.

[0018] Through the above technical solutions, the shape of the welded part is more uniform, and the structure of the enclosed flow cavity is more consistent, which can ensure that the flow state of the phase change material is consistent as much as possible, eliminate the problem of local unevenness and uneven flow resistance in the flow cavity caused by the difference in the shape of the welded part, reduce the turbulence disturbance when the gaseous phase change material rises and the liquid phase change material falls, reduce the overall flow resistance of the phase change material, and ensure the smooth circulation flow of the phase change material.

[0019] Furthermore, the welded part is a spot weld or a strip weld.

[0020] Through the above technical solutions, both spot welding and strip welding structures have high regularity, which is more suitable for the forming requirements of straight-through flow cavities and will not abruptly disturb the flow state of phase change materials in the flow cavity. Among them, spot welding occupies less space in the flow cavity and has less interference with the flow of phase change materials; strip welding can form a directional guiding effect on the phase change materials in the flow cavity, further optimizing the directional flow effect of phase change materials.

[0021] Furthermore, all of the aforementioned welded parts are the same size.

[0022] The above technical solutions aim to maintain the overall regularity of the flow cavity of the heat exchange plate as much as possible, and to ensure that the flow resistance and flow rate of the phase change material inside each flow cavity are more consistent, thereby reducing the problem of uneven flow of phase change material and unbalanced heat exchange load caused by differences in the size of the welded parts.

[0023] Furthermore, the spacing between adjacent welded portions is greater than the width of the welded portion.

[0024] The above technical solutions maximize the effective flow cross-sectional area of ​​the flow cavity, reduce the obstruction and encroachment of the welded part on the flow channel, further reduce the gas-liquid two-phase flow resistance of the phase change material, accelerate the circulation flow rate of the phase change material, and improve the cross-cavity heat transfer efficiency of the phase change material. Attached Figure Description

[0025] The present invention will be further described below with reference to the accompanying drawings: Figure 1This is a schematic diagram of the plate vacuum heat exchanger of this utility model; Figure 2 This is a schematic diagram of the heat exchange plate in this utility model.

[0026] In the figure, 10 is the upper heat exchange chamber; 11 is the channel for the fluid to be heat exchanged; 20 is the lower heat exchange chamber; 21 is the flue gas channel; 30 is the heat exchange plate; 301 is the thin plate; 302 is the welded part; 303 is the flow chamber; and 304 is the partition. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments.

[0028] The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the utility model described herein can be implemented in orders other than those illustrated or described herein.

[0029] It should be understood that in the various embodiments of this utility model, the number of each process does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this utility model.

[0030] It should be understood that in this invention, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or device.

[0031] It should be understood that in this utility model, "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, or Y alone. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "Contains X, Y, and Z", "Contains X, Y, and Z" means that all three X, Y, and Z are contained; "Contains X, Y, or Z" means that one of X, Y, and Z is contained; "Contains X, Y, and / or Z" means that any one, two, or three of X, Y, and Z are contained.

[0032] The technical solution of this utility model will be described in detail below with specific embodiments. The following specific embodiments can be selected to 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 Figure 1 and Figure 2 As shown, this utility model provides a plate vacuum heat exchanger, including an upper heat exchange chamber 10 and a lower heat exchange chamber 20. Both the upper heat exchange chamber 10 and the lower heat exchange chamber 20 are provided with heat exchange plates 30 spaced apart. Each heat exchange plate 30 is formed by welding two thin plates 301 together with multiple welding parts 302. The non-welded areas of the two thin plates 301 form a flow cavity 303, which contains a phase change material. The space between two adjacent heat exchange plates 30 in the lower heat exchange chamber 20 is a flue gas passage. Channel 21, the upper heat exchange cavity 10 has a flow channel 11 between two adjacent heat exchange plates 30. The flow cavity 303 of the upper heat exchange cavity 10 is connected to the flow cavity 303 of the lower heat exchange cavity 20. Multiple welded parts 302 are arranged in a straight line at equal intervals along the transverse and longitudinal directions of the heat exchange plates 30. The transverse welded parts 302 are aligned with each other, and the longitudinal welded parts 302 are aligned with each other. The adjacent welded parts 302 along the transverse and longitudinal directions are surrounded to form a straight through flow cavity 303.

[0034] During heat exchange, flue gas flows from left to right through flue gas channel 21. The phase change material circulates vertically between the upper heat exchange chamber 10 and the lower heat exchange chamber 20, while the fluid to be heat-exchanged flows from left to right through the fluid to be heat-exchanged channel 11. Specifically, high-temperature flue gas in the lower heat exchange chamber 20's flue gas channel 21 heats the liquid phase change material inside the flow chamber 303 through the thin plate 301. The liquid phase change material absorbs heat and vaporizes, turning into a gaseous state. The neat arrangement of the welded parts 302 ensures that the flow chamber 303 is a straight, continuous structure without bends, inflections, local narrowing, or structural interruptions. This minimizes the upward flow resistance of the gaseous phase change material, allowing it to rise more quickly along the flow chamber 303 and reducing stagnation. After the high-temperature gaseous phase change material enters the flow chamber 303 of the upper heat exchange chamber 10, it transfers heat to the low-temperature fluid to be heat-exchanged. The phase change material releases heat and condenses, liquefying into a liquid phase change. The material falls back and flows back under gravity. The straight-through flow cavity 303 can minimize backflow obstruction, further accelerating the overall circulation rate of the phase change material and improving heat exchange performance. At the same time, the neatly arranged welded parts 302 more evenly limit the thin plate 301, which can minimize the deformation of the thin plate 301 and squeeze the flow cavity 303. In addition, both the upper heat exchange cavity 10 and the lower heat exchange cavity 20 use heat exchange plates 30, which makes the vaporization, heat transfer, condensation and backflow of the phase change material in the upper heat exchange cavity 10 and the lower heat exchange cavity 20 more synchronized, and the heat exchange material more evenly distributed. This effectively improves the heat transfer efficiency of the phase change material and the heat exchange uniformity of the whole machine, ensuring continuous, efficient and stable operation of gas-liquid phase change heat exchange.

[0035] Meanwhile, the welding section 302 is arranged in a regular rectangular array. In addition to affecting the internal flow cavity 303 of the heat exchange plate 30, it can also improve the external structure of the heat exchange plate 30, making the cross-sectional dimensions of the flue gas channel 21 between the plates of the lower heat exchange cavity 20 and the heat exchange fluid channel 11 between the plates of the upper heat exchange cavity 10 more uniform. This reduces the flow resistance between the flue gas and the heat exchange fluid, eliminates the local stagnation and flow deviation of the flue gas and the heat exchange fluid as much as possible, optimizes the overall flow field distribution of the heat exchange fluid and flue gas on the outside, improves the flow uniformity of the flue gas and the heat exchange fluid, and strengthens the contact heat exchange effect between the heat exchange fluid, flue gas and the heat exchange plate 30. This improves the heat exchange between the heat exchange fluid, flue gas and the phase change material, and further improves the waste heat recovery efficiency of the whole machine.

[0036] It should be noted that the phase change material can be any one of composite paraffin-based phase change materials, inorganic salt-based phase change materials, or composite fatty acid phase change materials. This type of phase change material has a gas-liquid phase change range suitable for the flue gas heat exchange temperature conditions of the equipment, a large latent heat of vaporization, high heat storage and release efficiency, strong gas-liquid conversion reversibility, long cycle life, better gas phase fluidity, and better liquid phase gravity reflux effect. The 301 thin plate is made of metal.

[0037] It should be noted that the heat exchange plate 30 is equipped with a valve for connecting to a vacuum pump, which allows air and other gases to be extracted from inside the heat exchange plate 30, creating a vacuum or low-pressure environment. This facilitates the utilization of the unique thermophysical properties of fluids under vacuum conditions, such as enabling phase change materials to evaporate and absorb heat at lower temperatures, thereby improving heat transfer efficiency. Furthermore, during equipment maintenance, this valve can be connected to relevant testing equipment to perform pressure testing, leak detection, and other operations inside the heat exchange plate 30, quickly and accurately determining whether there are any faults or potential hazards in the equipment. For example, after vacuuming and closing the valve, observing the system pressure changes can identify any leaks, facilitating timely detection and repair of problems and ensuring the safe and stable operation of the equipment.

[0038] Furthermore, multiple welded parts 302 are arranged in a rectangular array. For example, the welded parts 302 of the entire heat exchange plate 30 are arranged in a rectangular array, which makes the cavity outline of the flow cavity 303 more consistent. This allows the gaseous and liquid phase change materials in the flow cavity 303 to flow more evenly, and the phase change materials in each region of the heat exchange plate 30 to undergo phase change under heat and the cross-cavity flow conditions to be more consistent, resulting in more uniform heat exchange.

[0039] Of course, the heat exchange plate 30 can also be equipped with separators 304 that divide the flow chambers 303 into multiple independent rectangular arrays. The separators 304 can be welding rods, which allows the phase change material to flow more orderly in each independent flow chamber 303, thereby improving heat exchange efficiency and avoiding blockage problems caused by poor flow of phase change material. Secondly, when the heat exchange plate 30 is damaged, since it is a structure of multiple independent flow chambers 303, even if the thin plate 301 corresponding to individual flow chambers 303 is partially damaged, it is not necessary to replace the entire thin plate 301 or use patch repairs with subsequent risks as in the past. Only the damaged flow chambers 303 need to be repaired by using a sealing structure. Therefore, there is no need for long-term shutdown, and it will not affect the heat exchange efficiency of other flow chambers 303, which greatly reduces the maintenance cost of the heat exchange plate 30 after damage.

[0040] Furthermore, the spacing of the transverse welding parts 302 of the heat exchange plate 30 is the same as that of the longitudinal welding parts 302, so as to eliminate the difference in transverse and longitudinal flow resistance as much as possible, and avoid the problems of local flow lag and uneven phase change rate of the phase change material as much as possible. This allows the phase change material in the heat exchange plate 30 to absorb and release heat and the gas-liquid conversion conditions to be more synchronized, and further improves the heat uniformity of the heat exchange plate 30.

[0041] Among them, the welding part 302 is a spot weld, which has a high degree of regularity and is more suitable for the forming requirements of the straight through flow cavity 303. It will not abruptly disturb the flow state of the phase change material in the flow cavity 303, occupy less space in the flow cavity 303, and have extremely low interference to the flow of the phase change material.

[0042] The welded parts 302 arranged horizontally and vertically on the heat exchange plate 30 are all intermittently welded, and the inner wall of the flow cavity 303 is smoother and more even, which further reduces the frictional resistance of the gaseous phase change material flowing upward and the liquid phase change material flowing back by gravity, making the two-phase flow of the phase change material more stable.

[0043] Furthermore, the multiple welded parts 302 have the same shape, and the structure of the flow cavity 303 formed by them is more consistent, so as to ensure that the flow state of the phase change material is consistent as much as possible. This eliminates the problem of local unevenness and uneven flow resistance in the flow cavity 303 caused by the difference in the shape of the welded parts 302, reduces the turbulence disturbance when the gaseous phase change material rises and the liquid phase change material falls, and reduces the overall flow resistance of the phase change material, ensuring the smooth circulation of the phase change material.

[0044] Multiple welded parts 302 are the same size to maintain the regularity of the overall flow cavity 303 of the heat exchange plate 30 as much as possible, and to ensure that the flow resistance and flow rate of the phase change material inside each flow cavity 303 are more consistent, thereby reducing the problem of uneven flow of phase change material and unbalanced heat exchange load caused by the size difference of the welded parts 302.

[0045] This ensures that the transverse and longitudinal cross sections of the flow cavity 303 are the same, making the gas-liquid two-phase flow pattern and flow rate of the phase change material more constant throughout the process, minimizing the need to overcome additional flow losses caused by abrupt changes in cross section, and ensuring uniform circulation of the phase change material as much as possible.

[0046] The spacing between adjacent welded parts 302 is greater than the width of the welded parts 302, so as to maximize the effective flow cross-sectional area of ​​the flow cavity 303, reduce the obstruction and squeezing of the flow channel by the welded parts 302, further reduce the gas-liquid two-phase flow resistance of the phase change material, accelerate the circulation flow rate of the phase change material, and improve the cross-cavity heat transfer efficiency of the phase change material.

[0047] The flow chambers 303 in the upper heat exchange chamber 10 and the lower heat exchange chamber 20 are arranged in the same direction. The flow chambers 303 are smoothly connected without misalignment or flow direction bends, which can further reduce the overall flow resistance of the gaseous phase change material being transported upward and the liquid phase change material being dropped downward by gravity, weaken the flow loss caused by the misalignment of the flow chambers 303, and make the gas-liquid two-phase circulation flow of the phase change material smoother.

[0048] Understandably, in other embodiments, the welded part is a strip weld, such as a vertical strip, which can form a directional flow guiding effect on the phase change material in the flow cavity, further optimizing the directional flow effect of the phase change material.

[0049] In addition to the preferred embodiments described above, there are other embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection claimed by this utility model.

Claims

1. A plate-type vacuum heat exchanger, comprising an upper heat exchange chamber (10) and a lower heat exchange chamber (20), wherein both the upper heat exchange chamber (10) and the lower heat exchange chamber (20) are provided with heat exchange plates (30) spaced apart, each heat exchange plate (30) being fixed by welding two thin plates (301) through multiple welding parts (302), the non-welded areas of the two thin plates (301) forming a flow chamber (303), the flow chamber (303) being provided with a phase change material, a flue gas passage (21) between two adjacent heat exchange plates (30) in the lower heat exchange chamber (20), and a fluid passage (11) to be heat exchanged between two adjacent heat exchange plates (30) in the upper heat exchange chamber (10), wherein the flow chamber (303) of the upper heat exchange chamber (10) and the flow chamber (303) of the lower heat exchange chamber (20) are connected, characterized in that, Multiple welded parts (302) are arranged equidistantly in a straight line along the heat exchange plate (30) in both the transverse and longitudinal directions. The welded parts (302) in the transverse direction are aligned with each other, and the welded parts (302) in the longitudinal direction are aligned with each other. The welded parts (302) adjacent to each other in the transverse and longitudinal directions enclose each other to form a straight through flow cavity (303).

2. The plate vacuum heat exchanger according to claim 1, characterized in that, The multiple welded parts (302) are arranged in a rectangular array.

3. The plate vacuum heat exchanger according to claim 1, characterized in that, The spacing between the transverse welded portions (302) and the longitudinal welded portions (302) of the heat exchange plate (30) are the same.

4. The plate vacuum heat exchanger according to claim 1, characterized in that, The welded parts (302) arranged horizontally and vertically on the heat exchange plate (30) are all formed by intermittent welding.

5. The plate vacuum heat exchanger according to claim 1, characterized in that, The flow cavity (303) has the same cross-section in both the transverse and longitudinal directions.

6. The plate vacuum heat exchanger according to claim 1, characterized in that, The upper heat exchange cavity (10) and the flow cavity (303) in the lower heat exchange cavity (20) are arranged in the same direction.

7. The plate vacuum heat exchanger according to claim 1, characterized in that, The multiple welded parts (302) have the same shape.

8. The plate vacuum heat exchanger according to claim 1, characterized in that, The welding part (302) is a spot weld or a strip weld.

9. The plate vacuum heat exchanger according to claim 1, characterized in that, The multiple welded parts (302) are the same size.

10. The plate vacuum heat exchanger according to claim 1, characterized in that, The spacing between adjacent welded portions (302) is greater than the width of the welded portion (302).

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