Tubular paraffin heat storage device

Abstract

The invention discloses a tube nest type paraffin heat storage device, and relates to the technical field of heat storage devices, the tube nest type paraffin heat storage device comprises an outer shell, a mounting shell and a plurality of groups of tube nest assemblies, each tube nest assembly comprises a fixing frame, a plurality of heat storage tubes and tube hoops used for fixing the heat storage tubes, and each heat storage tube comprises a tube body, a heat storage medium and a heat exchange promoting mechanism. The heat exchange promoting mechanism is arranged in the pipe body and used for removing solid paraffin solidified on the inner wall of the pipe body in the heat release process and pushing the solid paraffin towards the inner wall of the pipe body in the heat absorption process so as to promote heat exchange. The heat exchange promoting mechanism is arranged in the heat storage pipe, solid paraffin solidified on the inner wall of the pipe body can be effectively removed in the heat release stage, heat resistance is reduced, it is ensured that heat is smoothly transmitted to liquid paraffin, and heat release is completed; and the contact area between the paraffin and the pipe wall is increased, and efficient absorption of heat is promoted.

Description

Technical Field

[0001] The invention relates to the technical field of heat storage devices, and in particular to a tubular paraffin heat storage device. Background Art

[0002] With the country's emphasis on and promotion of energy storage and heat storage technology, phase change heat storage technology has been widely used in many fields such as solar thermal collection, industrial waste heat utilization, waste heat recovery and building energy conservation due to its significant advantages such as constant temperature, high heat storage density, small heat storage container volume and high thermal efficiency. Especially in the field of building heating and air conditioning, phase change heat storage technology has become a hot topic of research at home and abroad.

[0003] As a common energy storage material, paraffin wax has been widely used in the field of building energy conservation due to its high phase change enthalpy, stable chemical properties, non-toxic and harmless, stable phase change process and adjustable phase change temperature. According to the specific requirements of the phase change temperature, different types of paraffin wax can be selected to meet various application scenarios such as medium-temperature heat storage, floor heat storage or solar heat storage. According to the standard of "GB / T 1202-2016 Crude Paraffin Wax", the melting point range of paraffin wax covers 50℃ to 70℃. For example, the melting point of No. 50 crude paraffin wax is 50℃, and so on to No. 70 crude paraffin wax. Its melting point temperature is usually consistent with the label, because the water temperature of hot water central heating projects is usually between 50℃ and 75℃, which coincides with the common melting point temperature of paraffin wax, making paraffin wax an ideal choice for hot water central heating projects.

[0004] The thermal conductivity of paraffin is relatively poor, and its volume changes significantly during the solid-liquid phase change process. Among them, the patent with application number 2019216412211 proposes a shell-and-tube structure that uses metal tubes to store paraffin, and sets metal wires in the tubes to enhance thermal conductivity. However, this structure has limitations, because the water in the shell flows axially along the metal tube, and the metal tube cannot effectively disturb the water flow. The addition of metal wires mainly strengthens the axial heat conduction process in the tube, and has limited effect on radial heat conduction. In addition, due to the volume change during the solid-liquid phase change of paraffin, it is necessary to use thickened metal tubes or fill nitrogen when making the heat exchange tubes, which not only increases the manufacturing cost, but also increases the difficulty of the manufacturing process.

[0005] Another improvement is the patent with application number 2024102147042, which proposes a graded phase change heat storage tank, which uses an oil storage tank as a carrier, and a water circulation coil is set in the tank. Paraffin wax of different temperatures is filled between the coil and the tank body as a heat storage medium. However, this device also has problems in practical applications. Due to the poor thermal conductivity of paraffin wax and the uneven thickness distribution (the paraffin wax between the coils is thinner, and the paraffin wax in the center and corners of the tank body is thicker), during the heat storage process, only a small amount of paraffin wax outside the coil will solidify in a short time, and the melting and solidification of the paraffin wax in the tank are uneven. This is not only not conducive to the rapid response of the thermal system, but also reduces the actual utilization rate of paraffin wax. Summary of the invention

[0006] The purpose of the present invention is to solve the problems of small heat exchange area, low heat exchange efficiency and insufficient solidification and melting of paraffin wax in short-time heat exchange in the phase change heat storage tank in the prior art, and to propose a tubular paraffin heat storage device.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions: A tube-in-tube paraffin heat storage device comprises an outer shell, a mounting shell and a plurality of tube-in-tube assemblies, wherein: A water inlet pipe is arranged at the lower part of the outer shell, and a water outlet pipe is arranged at the upper part of the outer shell; The installation shell is a rectangular shell with two ends open, and the installation shell is fixedly installed in the outer shell and is provided with an upper fixing frame and a lower fixing frame for supporting multiple groups of tube assemblies; The tube array assembly includes a fixing frame, a plurality of heat storage tubes and a pipe clamp for fixing the heat storage tubes, and a plurality of groups of the tube array assemblies are stacked in sequence along the longitudinal direction starting from the lower fixing frame until reaching the upper fixing frame; The heat storage pipe comprises: The tube body has an interior divided into a heat storage area and buffer areas located at both ends of the heat storage area along the length direction; A heat storage medium is filled in the heat storage area, wherein the heat storage medium is paraffin with a melting point between 50° C. and 70° C.; The heat exchange promotion mechanism is arranged in the tube body and is used to remove the solid paraffin solidified on the inner wall of the tube body during the heat release process, and to push the solid paraffin toward the inner wall of the tube body to promote heat exchange during the heat absorption process.

[0008] Preferably, the heat exchange promoting mechanism comprises: The pushing structure can rotate and move in the heat storage area; The driving structure buffers the volume change of the paraffin when the paraffin changes phase and drives the pushing structure to move at the same time.

[0009] Preferably, the pushing structure includes two groups of symmetrically arranged pushing elements, the pushing elements include a sealing block, a plurality of scraper cylinders and a scraper strip connecting the plurality of scraper cylinders, wherein the sealing block is sealingly and slidably arranged in the buffer area, the side wall of the scraper cylinder has a plurality of openings, the plurality of scraper cylinders are equidistantly arranged in the heat storage area and adhere to the inner wall of the heat storage area, the scraper strip is adhered to the inner wall of the heat storage area and is slidably connected to the scraper cylinder of another group of pushing elements.

[0010] Preferably, the scraper is conical, and the small diameter end of the scraper is close to the sealing block. When the paraffin changes from liquid phase to solid phase, the large diameter ends of the scraper barrels of the two groups of pushing elements approach each other until they fit together. When the paraffin changes from solid phase to liquid phase, the small diameter ends of the scraper barrels of the two groups of pushing elements approach each other until they fit together.

[0011] Preferably, the length of the scraper strip is consistent with the length of the heat storage area, and the scraper strip comprises a rigid portion and an elastic portion, the rigid portion is in contact with the inner wall of the tube body, and the elastic portion is arc-shaped and extends toward the inside of the tube body.

[0012] Preferably, the cross-section of the rigid part is wedge-shaped, forming a large angle side and a small angle side with the inner wall of the tube body. When the paraffin changes from liquid phase to solid phase, the rigid part rotates toward the large angle side, and when the paraffin changes from solid phase to liquid phase, the rigid part rotates toward the small angle side.

[0013] Preferably, the driving structure comprises a driving rod fixedly mounted on the end of the tube body, the outer surface of the driving rod has a spiral pattern, the center of the sealing block is provided with a special-shaped hole adapted to the surface pattern of the driving rod, and a spring is arranged between the sealing block and the end of the tube body.

[0014] Preferably, the heat storage tubes of two adjacent groups of tube-in-tube assemblies are laterally staggered so that the projections of the heat storage tubes in the two adjacent groups of tube-in-tube assemblies on the horizontal plane do not completely overlap.

[0015] Preferably, the upper ends of the fixing frame and the lower fixing frame are provided with protrusions, and the lower ends of the fixing frame and the upper fixing frame are provided with bayonet holes, so that the upper fixing frame, the lower fixing frame and the fixing frames at adjacent positions can be snap-fitted.

[0016] Preferably, the bottom surface of the lower fixing frame is flush with the upper tangent line of the water inlet pipe, and the upper fixing frame is flush with the lower tangent line of the water outlet pipe.

[0017] Compared with the prior art, the present invention has the following advantages: 1. The present invention adopts paraffin as the heat storage medium. Based on the high heat storage density per unit volume of paraffin, compared with the traditional water tank heat storage method, paraffin can store a large amount of heat energy in a smaller volume, thereby greatly reducing the footprint of the heat storage equipment. In addition, by arranging stacked tube components in sequence, not only the heat exchange area is increased, but also the effective exchange of heat energy between paraffin and the heat transfer medium is promoted, which solves the problems of small heat exchange area and low heat exchange efficiency in traditional paraffin heat storage devices, ensures that even under short-time heat exchange conditions, paraffin can be fully solidified and melted, and improves the overall efficiency of the system.

[0018] 2. In the traditional paraffin heat storage device, since paraffin has poor thermal conductivity and is easily condensed on the inner wall of the tube body to form a thermal resistance layer during the heat exchange process, the heat exchange rate is greatly reduced. The present invention arranges a heat exchange promotion mechanism in the heat storage tube, which can effectively remove the solid paraffin solidified on the inner wall of the tube body in the heat release stage, reduce thermal resistance, ensure that heat is smoothly transferred to the liquid paraffin, and complete heat release. At the same time, in the heat absorption stage, the heat exchange promotion mechanism actively pushes the solid paraffin to the inner wall of the tube body, increases the contact area between the paraffin and the tube wall, and promotes the efficient absorption of heat, thereby significantly improving the heat exchange efficiency of the entire system. When releasing heat, the paraffin layer on the inner wall of the tube is removed to avoid the accumulation of thermal resistance; when absorbing heat, it ensures that the solid paraffin maintains good contact with the tube wall, making the heat transfer more uniform and efficient, and effectively solving the common "tube wall effect" in paraffin heat storage, that is, after the paraffin near the tube wall melts quickly, the internal solid paraffin has low heat exchange efficiency due to insufficient contact.

[0019] 3. The heat exchange promotion mechanism in the present invention utilizes the volume change of paraffin during phase change as the power, and can realize the movement of the pushing structure without external energy input, which not only reduces the energy consumption of the system, but also improves the energy utilization efficiency, which is in line with the green and sustainable development concept. The driving structure is not only responsible for driving the pushing structure, but also can effectively buffer the volume change of paraffin during the phase change process, prevent abnormal internal pressure or structural damage of the tube body caused by sudden volume change, and enhance the stability and durability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the overall structure of a tubular paraffin heat storage device proposed by the present invention; Figure 2 This is a schematic cross-sectional view of a tubular paraffin heat storage device proposed by the present invention; Figure 3 for Figure 2 A schematic diagram of the enlarged structure of part A; Figure 4 This is a schematic diagram of the installation and arrangement structure of multiple groups of tube-in-tube components of a tube-in-tube paraffin heat storage device proposed by the present invention; Figure 5 for Figure 4A schematic diagram of the enlarged structure of part B; Figure 6 A schematic diagram of the explosion structure of a middle heat storage tube of a tubular paraffin heat storage device proposed by the present invention; Figure 7 for Figure 6 A schematic diagram of the enlarged structure of the middle C part; Figure 8 This is a schematic structural diagram of a heat storage tube in a paraffin solid phase state of a tubular paraffin heat storage device proposed by the present invention; Fig. 9 This is a schematic structural diagram of a heat storage tube in a paraffin liquid phase state of a tubular paraffin heat storage device proposed by the present invention; Fig.10 This is a schematic diagram of the structure of a tubular paraffin heat storage device proposed by the present invention in which the paraffin is transformed from liquid phase to solid phase by a scraper working state; Fig.11 This is a schematic diagram of the structure of a tubular paraffin heat storage device proposed by the present invention, in which the paraffin is transformed from a solid phase to a liquid phase by a scraper working state; Fig.12 A schematic diagram of the structure of a tubular paraffin heat storage device proposed by the present invention in which the paraffin is transformed from liquid phase to solid phase scraper working state; Fig.13 A schematic diagram of the structure of a tubular paraffin heat storage device proposed by the present invention in which the paraffin is transformed from a solid phase to a liquid phase scraper working state; Fig.14 This is a schematic diagram of the structure of a driving structure in a shell-and-tube paraffin heat storage device proposed by the present invention.

[0021] In the figure: 1. outer shell; 11. water inlet pipe; 12. water outlet pipe; 2. mounting shell; 21. upper fixing frame; 22. lower fixing frame; 23. protrusion; 24. bayonet; 3. tube assembly; 31. fixing frame; 32. heat storage tube; 321. tube body; 3211. heat storage area; 3212. buffer area; 322. heat storage medium; 323. heat exchange promotion mechanism; 33. pipe clamp; 4. pushing structure; 41. sealing block; 411. special-shaped hole; 42. scraper; 421. opening; 43. scraper strip; 431. rigid part; 432. elastic part; 5. driving structure; 51. driving rod; 52. spring. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0023] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside" and "outside" etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0024] Reference Figure 1-5 A shell-and-tube paraffin heat storage device comprises an outer shell 1, a mounting shell 2 and a plurality of groups of shell-and-tube assemblies 3. A heat-insulating interlayer is provided between the outer shell 1 and the mounting shell 2. The shell-and-tube assemblies 3 are located in the mounting shell 2. The heat loss in the mounting shell 2 is effectively reduced by the heat-insulating interlayer, thereby improving the heat storage effect of the heat storage device.

[0025] A water inlet pipe 11 is provided at the lower part of the outer shell 1, and a water outlet pipe 12 is provided at the upper part of the outer shell 1. The water inlet pipe 11 and the water outlet pipe 12 are connected to the thermal network. After water enters from the water inlet pipe 11, it flows through the gap between the tube components 3 and completes the heat exchange. Since the water enters from the bottom and exits from the top, the water will submerge all the tube components 3 to fully exchange heat. The water after heat exchange flows out from the water outlet pipe 12 and enters the inlet of the next heat storage device or flows back to the thermal network.

[0026] The installation shell 2 is a rectangular shell with two ends open. The installation shell 2 is fixedly installed in the outer shell 1 and is provided with an upper fixing frame 21 and a lower fixing frame 22 for supporting a plurality of tube array assemblies 3 .

[0027] Reference Figure 1-5 The tube assembly 3 includes a fixing frame 31, a plurality of heat storage tubes 32 and a pipe clamp 33 for fixing the heat storage tubes 32. The fixed spacing of the heat storage tubes 32 should be set according to the water flow rate flowing through the heat storage device. The spacing size is related to the cross-sectional area of ​​the flow channel. In principle, the water flow rate flowing through the heat storage tubes 32 should be 0.8-3m / s. The plurality of groups of tube assemblies 3 are stacked in sequence along the longitudinal direction starting from the lower fixing frame 22 until reaching the upper fixing frame 21. The multi-layer stacking form of the tube assembly 3 enhances heat transfer, has a long service life and a large heat exchange area, and solves the problems of small heat exchange area, low heat exchange efficiency, and insufficient solidification and melting of paraffin wax in a short heat exchange in the paraffin heat storage device.

[0028] The bottom surface of the lower fixing frame 22 is flush with the upper tangent line of the water inlet pipe 11, and the upper fixing frame 21 is flush with the lower tangent line of the water outlet pipe 12, ensuring that the water fully covers the tube assembly 3 when flowing through the heat storage device, thereby ensuring efficient heat exchange.

[0029] The upper ends of the fixing frame 31 and the lower fixing frame 22 are provided with protrusions 23, and the lower ends of the fixing frame 31 and the upper fixing frame 21 are provided with snap-fitting holes 24, so that the upper fixing frame 21, the lower fixing frame 22 and the fixing frames 31 at adjacent positions can be snap-fitted together, and the upper fixing frame 21, the lower fixing frame 22 and multiple fixing frames 31 can be snap-fitted together in the vertical direction for stable assembly, which simplifies the installation process, improves assembly efficiency, and ensures the stability of the tube array assembly 3 in the vertical direction.

[0030] Reference Figure 3 The heat storage tubes 32 of two adjacent groups of tube-in-tube assemblies 3 are laterally staggered, so that the projections of the heat storage tubes 32 in the two adjacent groups of tube-in-tube assemblies 3 on the horizontal plane do not completely overlap, thereby improving the space utilization when the tube-in-tube assemblies 3 are distributed. At the same time, this layout method also helps water to flow through the heat storage tubes 32 more evenly, thereby improving the uniformity and efficiency of heat exchange.

[0031] Reference Figure 6-11 The heat storage tube 32 includes a tube body 321, a heat storage medium 322 and a heat exchange promotion mechanism 323. The tube body 321 is made of metal, and in this embodiment, stainless steel is used, which has sufficient strength and good thermal conductivity.

[0032] The interior of the tube body 321 is divided into a heat storage area 3211 and buffer areas 3212 located at both ends of the heat storage area 3211 along the length direction.

[0033] The heat storage medium 322 is filled in the heat storage area 3211. The heat storage medium 322 is paraffin with a melting point between 50-70°C. The use of paraffin as the heat storage medium 322 has a large heat storage density per unit volume and a small footprint, which solves the problem of large footprint of traditional water tank heat storage. The specific usage grade of paraffin is determined according to the water temperature in the thermal pipeline network of the hot water centralized heating project.

[0034] In the process of heat storage and release of traditional paraffin heat storage devices, the heat transfer speed inside the heat storage material is slow due to the poor thermal conductivity of paraffin itself. Only the paraffin near the inner wall of the heat exchange pipe can achieve rapid heat exchange. The paraffin located in the center of the heat exchange pipe has low heat transfer efficiency due to the barrier of the outer layer of paraffin. During the heat absorption process of paraffin (converting from solid phase to liquid phase), the paraffin near the inner wall of the heat exchange pipe melts quickly, and the liquid phase paraffin fills the gap between the remaining solid phase paraffin and the inner wall of the heat exchange pipe, hindering the smooth transfer of heat. In particular, during the heat release process (transformation from liquid phase to solid phase) of paraffin, the liquid phase paraffin will directly condense on the inner wall of the heat exchange pipe to form a layer of solid paraffin thermal resistance layer when it releases heat and solidifies. This thermal resistance layer not only hinders the smooth transfer of heat, but also reduces the heat exchange efficiency, which greatly reduces the overall performance of the heat storage system. The heat exchange promotion mechanism 323 is provided to remove the solid paraffin solidified on the inner wall of the tube body 321 during the heat release process, and to push the solid paraffin toward the inner wall of the tube body 321 during the heat absorption process to promote heat exchange.

[0035] Reference Figure 6-11 The heat exchange promotion mechanism 323 is arranged in the tube body 321. The heat exchange promotion mechanism 323 includes a pushing structure 4 and a driving structure 5. The driving structure 5 buffers the volume change of the paraffin when the paraffin changes phase and drives the pushing structure 4 to move. The pushing structure 4 can rotate and move in the heat storage area 3211 to remove the solid paraffin solidified on the inner wall of the tube body 321 during the heat release process, and push the solid paraffin toward the inner wall of the tube body 321 during the heat absorption process to promote heat exchange.

[0036] The volume change of paraffin wax mainly depends on its solid and liquid densities and the properties of phase change. When the solid state changes to the liquid state, the increase in temperature has little direct effect on the volume change. In actual situations, the effect on the heat storage tube 32 can be ignored. Under normal conditions, the density of solid paraffin wax is about 0.9g / cm³, and the density of liquid paraffin wax is about 0.8g / cm³. Since the paraffin wax is sealed in the tube body 321, the mass of the paraffin wax does not change when the phase change occurs. Therefore, the volume change of the paraffin wax when it changes from the solid phase to the liquid phase can be calculated. Specifically: Paraffin volume change rate ; Simplification can give the paraffin volume change rate

[0037] Where ΔV is the volume change; ρ g is the density of solid paraffin, about 0.9g / cm³; ρ l is the density of liquid paraffin, about 0.8g / cm³; V g is the volume of solid paraffin; V lis the volume of liquid paraffin; M is the mass of paraffin.

[0038] From the above, it can be seen that the volume changes significantly during the solid-liquid phase change process, the inner diameter of the tube body 321 remains unchanged, and the axial length of the paraffin in the tube body 321 increases by about 12.5%. Therefore, the volume change during the phase change of the paraffin can be used as a driving force, and the movement of the pushing structure 4 can be achieved without external energy input, which not only reduces the energy consumption of the system, but also improves the energy utilization efficiency, which is in line with the green and sustainable development concept. The driving structure 5 is not only responsible for driving the pushing structure 4, but also can effectively buffer the volume change of the paraffin during the phase change process, prevent abnormal internal pressure or structural damage of the tube body 321 caused by sudden volume changes, and enhance the stability and durability of the system.

[0039] Reference Figure 6-11 The pushing structure 4 includes two groups of symmetrically arranged pushing elements, the pushing elements include a sealing block 41, a plurality of scrapers 42 and a scraper strip 43 connecting the plurality of scrapers 42, wherein the sealing block 41 is sealingly and slidably arranged in the buffer area 3212, and when the phase of the paraffin changes, the sealing block 41 is driven to move axially along the tube body 321 by the volume change of the paraffin, and the side wall of the scraper tube 42 has a plurality of openings 421, and since the scraper tube 42 moves with the scraper strip 43, the liquid phase paraffin in the tube body 321 can flow freely through the openings 421, thereby ensuring that the pressure of each part in the tube body 321 is consistent, and the plurality of scrapers 42 are equidistantly arranged in the heat storage area 3211 and are in contact with the inner wall of the heat storage area 3211, the scraper strip 43 is in contact with the inner wall of the heat storage area 3211 and is slidably connected with the scraper tube 42 of another group of pushing elements, and the scrapers 42 on different pushing elements are alternately arranged at intervals, and two adjacent scrapers 42 can cooperate to promote the heat exchange of the paraffin.

[0040] The scraper 42 is conical, and the small diameter end of the scraper 42 is close to the sealing block 41. When the paraffin changes from liquid phase to solid phase, the volume of the paraffin decreases, the sealing block 41 moves toward the heat storage area 3211, and the large diameter end of the scraper 42 moves forward to scrape off the solid phase paraffin layer formed on the inner wall of the tube body 321, and the unsolidified liquid phase paraffin supplements the scraped part, so as to quickly realize heat exchange. The large diameter ends of the scrapers 42 of the two sets of pushing elements approach each other until they fit together (such as Fig.10 As shown), at this time, the solid paraffin is sealed in the conical space formed by the two scrapers 42, which are located at the central axis of the tube body 321, so that the liquid paraffin gathers on the inner wall of the tube body 321, and the heat is quickly exchanged. When the paraffin changes from the solid phase to the liquid phase, the volume of the paraffin increases, and the sealing block 41 moves to the side away from the heat storage area 3211, and the small diameter end of the scraper 42 moves forward. During the movement, the liquid paraffin flows through the opening 421, and the small diameter ends of the scrapers 42 of the two sets of pushing elements approach each other until they fit together (as shown in FIG. Fig.11As shown in the figure, the solid paraffin cannot pass through the opening 421, and the solid paraffin is squeezed close to the inner wall of the tube body 321 by the small diameter end of the scraper 42. As the scraper 42 continues to move, the paraffin is liquefied by heat exchange at the inner wall of the tube body 321 and is immediately squeezed away, so that the solid paraffin continues to exchange heat with the inner wall of the tube body 321.

[0041] Reference Figure 6-14 Since the phase change of paraffin is a continuous process, the re-condensed or melted paraffin on the inner wall of the tube body 321 behind the moving direction of the scraper 42 cannot be processed by the scraper 42 during the continuous movement of the scraper 42. Under the action of the driving structure 5, the pushing structure 4 can rotate while moving in the heat storage area 3211. During rotation, the scraper bar 43 will promote heat exchange of the paraffin in the tube body 321 in all directions.

[0042] Specifically, the length of the scraper 43 is consistent with the length of the heat storage area 3211. When the paraffin is completely in the solid phase, the volume is the smallest and the distance between the two sealing blocks 41 is the smallest. During the solidification of the paraffin, the distance between the two sealing blocks 41 gradually decreases, and the sealing blocks 41 rotate forwardly. During the liquefaction of the paraffin, the distance between the two sealing blocks 41 gradually increases, and the sealing blocks 41 rotate reversely. The scraper 43 includes a rigid portion 431 and an elastic portion 432. The rigid portion 431 is in contact with the inner wall of the tube body 321, and the elastic portion 432 is an arc extending toward the inside of the tube body 321.

[0043] The rigid part 431 has a wedge-shaped cross section, and forms a large angle side and a small angle side with the inner wall of the tube body 321. When the paraffin changes from a liquid phase to a solid phase, the rigid part 431 rotates toward the large angle side, and the sealing block 41 rotates forward. When the paraffin changes from a solid phase to a liquid phase, the rigid part 431 rotates toward the small angle side, and the sealing block 41 rotates reversely.

[0044] Reference Figure 6-14 , when the sealing block 41 rotates forward (such as Fig.12 As shown in FIG. 4 ), the inner wall of the tube body 321 is scraped by the rigid part 431, and the scraped solid paraffin gathers toward the center of the tube body 321 along the elastic part 432, and along with the arc-shaped concave winding core of the elastic part 432, the liquid paraffin is ensured to flow toward the inner wall of the tube body 321. When the sealing block 41 rotates in the opposite direction (as shown in FIG. Fig.13 As shown in the figure, the unmelted solid paraffin accumulates along the convex surface of the elastic portion 432 toward the rigid portion 431, and as the accumulation of the solid paraffin increases, the elastic portion 432 will deform toward the concave side and generate elastic force, so that the elastic portion 432 applies an extrusion force on the solid paraffin toward the inner wall of the tube body 321, ensuring sufficient heat exchange between the solid paraffin and the inner wall of the tube body 321.

[0045] The driving structure 5 includes a driving rod 51 fixedly mounted at the end of the tube body 321, the outer surface of the driving rod 51 has a spiral pattern, and a special-shaped hole 411 adapted to the surface pattern of the driving rod 51 is opened in the center of the sealing block 41. When the sealing block 41 moves during the phase change of paraffin, the special-shaped hole 411 on the sealing block 41 cooperates with the pattern on the outside of the driving rod 51 to rotate the sealing block 41, and when the moving direction of the sealing block 41 is opposite, the rotation direction also changes. A spring 52 is arranged between the sealing block 41 and the end of the tube body 321. When the paraffin changes from a liquid phase to a solid phase, the elastic force of the spring 52 promotes the sealing block 41 to move toward the side of the heat storage area 3211.

[0046] The specific working principle of the present invention is as follows: The heat storage device is mainly used for water heat storage or fluid heat storage with similar properties. The heat storage temperature is related to the type of paraffin and can be selected according to the use requirements. Taking water heat storage in the thermal network as an example, the heat storage device has two processes: heat storage and heat release.

[0047] When in use, the water inlet pipe 11 and the water outlet pipe 12 are connected to the thermal network. After water enters from the water inlet pipe 11, it flows through the gap between the tube components 3 and completes the heat exchange. Since the water enters from the bottom and exits from the top, the water will submerge all the tube components 3 to fully exchange heat. The water after heat exchange flows out from the water outlet pipe 12 and enters the inlet of the next heat storage device or flows back to the thermal network.

[0048] When storing heat, the paraffin absorbs heat and changes from the liquid phase to the solid phase, the volume of the paraffin decreases, the sealing block 41 moves toward the side of the heat storage area 3211, and the large-diameter end of the scraper 42 moves forward to scrape off the solid-phase paraffin layer formed on the inner wall of the tube body 321, and the unsolidified liquid-phase paraffin replenishes the scraped part to quickly achieve heat exchange. The large-diameter ends of the scrapers 42 of the two sets of pushing elements approach each other until they fit together. At this time, the solid-phase paraffin is sealed in the conical space formed by the two scrapers 42, which is located at the center axis of the tube body 321, so that the liquid-phase paraffin gathers on the inner wall of the tube body 321 to quickly exchange heat.

[0049] When releasing heat, the paraffin changes from a solid phase to a liquid phase, the volume of the paraffin increases, the sealing block 41 moves to the side away from the heat storage area 3211, and the small-diameter end of the scraper 42 moves forward. During the movement, the liquid paraffin flows through the opening 421, and the small-diameter ends of the scrapers 42 of the two sets of pushing elements approach each other until they fit together, and the solid-phase paraffin cannot pass through the opening 421. Under the squeezing action of the small-diameter end of the scraper 42, the solid-phase paraffin approaches the inner wall of the tube body 321, and as the scraper 42 continues to move, the paraffin is liquefied after heat exchange at the inner wall of the tube body 321 and is immediately expelled by the squeezing action, so that the solid-phase paraffin continues to exchange heat with the inner wall of the tube body 321.

[0050] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A tubular paraffin heat storage device, comprising an outer shell (1), a mounting shell (2) and a plurality of tubular components (3), characterized in that: in: A water inlet pipe (11) is provided at the lower part of the outer shell (1), and a water outlet pipe (12) is provided at the upper part of the outer shell (1); The mounting shell (2) is a rectangular shell with two ends open; the mounting shell (2) is fixedly mounted in the outer shell (1) and is provided with an upper fixing frame (21) and a lower fixing frame (22) for supporting a plurality of tube array assemblies (3); The tube array assembly (3) comprises a fixing frame (31), a plurality of heat storage tubes (32) and a pipe clamp (33) for fixing the heat storage tubes (32); a plurality of groups of the tube array assemblies (3) are stacked in sequence along the longitudinal direction starting from the lower fixing frame (22) until reaching the upper fixing frame (21); The heat storage pipe (32) comprises: The tube body (321) has its interior divided into a heat storage area (3211) and buffer areas (3212) located at both ends of the heat storage area (3211) along its length direction; A heat storage medium (322) is filled in the heat storage area (3211), wherein the heat storage medium (322) is paraffin with a melting point between 50°C and 70°C; The heat exchange promotion mechanism (323) is arranged in the tube body (321) and is used to remove the solid paraffin solidified on the inner wall of the tube body (321) during the heat release process, and to push the solid paraffin toward the inner wall of the tube body (321) to promote heat exchange during the heat absorption process.

2. A tubular paraffin heat storage device according to claim 1, characterized in that: The heat exchange promoting mechanism (323) comprises: The pushing structure (4) is rotatable and movable within the heat storage area (3211); The driving structure (5) buffers the volume change of the paraffin when the paraffin changes phase, and at the same time drives the pushing structure (4) to move.

3. A tubular paraffin heat storage device according to claim 2, characterized in that: The pushing structure (4) comprises two groups of symmetrically arranged pushing elements, the pushing elements comprising a sealing block (41), a plurality of scraper cylinders (42) and a scraper strip (43) connecting the plurality of scraper cylinders (42), wherein the sealing block (41) is sealingly and slidably arranged in the buffer region (3212), the side wall of the scraper cylinder (42) has a plurality of openings (421), the plurality of scraper cylinders (42) are equidistantly arranged in the heat storage region (3211) and are in contact with the inner wall of the heat storage region (3211), and the scraper strip (43) is in contact with the inner wall of the heat storage region (3211) and is slidably connected to the scraper cylinder (42) of the other group of pushing elements.

4. A tubular paraffin heat storage device according to claim 3, characterized in that: The scraper cylinder (42) is conical, and the small diameter end of the scraper cylinder (42) is close to the sealing block (41). When the paraffin changes from a liquid phase to a solid phase, the large diameter ends of the scraper cylinders (42) of the two groups of pushing elements approach each other until they fit together. When the paraffin changes from a solid phase to a liquid phase, the small diameter ends of the scraper cylinders (42) of the two groups of pushing elements approach each other until they fit together.

5. The shell-and-tube paraffin heat storage device according to claim 3, characterized in that: The length of the scraper strip (43) is consistent with the length of the heat storage area (3211), and the scraper strip (43) comprises a rigid portion (431) and an elastic portion (432), wherein the rigid portion (431) is in contact with the inner wall of the tube body (321), and the elastic portion (432) is arc-shaped and extends toward the inside of the tube body (321).

6. A tubular paraffin heat storage device according to claim 5, characterized in that: The rigid portion (431) has a wedge-shaped cross section, and forms a large angle side and a small angle side with the inner wall of the tube body (321). When the paraffin changes from a liquid phase to a solid phase, the rigid portion (431) rotates toward the large angle side, and when the paraffin changes from a solid phase to a liquid phase, the rigid portion (431) rotates toward the small angle side.

7. The tubular paraffin heat storage device according to claim 3, characterized in that: The driving structure (5) comprises a driving rod (51) fixedly mounted on the end of the tube body (321); the outer surface of the driving rod (51) has a spiral pattern; a special-shaped hole (411) matching the pattern on the surface of the driving rod (51) is provided at the center of the sealing block (41); and a spring (52) is provided between the sealing block (41) and the end of the tube body (321).

8. The tubular paraffin heat storage device according to claim 1, characterized in that: The heat storage tubes (32) of two adjacent groups of tube-in-tube assemblies (3) are arranged in a transversely staggered manner, so that the projections of the heat storage tubes (32) in the two adjacent groups of tube-in-tube assemblies (3) on the horizontal plane do not completely overlap.

9. The tubular paraffin heat storage device according to claim 1, characterized in that: The upper ends of the fixing frame (31) and the lower fixing frame (22) are provided with protrusions (23), and the lower ends of the fixing frame (31) and the upper fixing frame (21) are provided with bayonet openings (24), so that the upper fixing frame (21), the lower fixing frame (22) and the fixing frames (31) at adjacent positions can be snap-fitted.

10. The tubular paraffin heat storage device according to claim 1, characterized in that: The bottom surface of the lower fixing frame (22) is flush with the upper tangent line of the water inlet pipe (11), and the bottom surface of the upper fixing frame (21) is flush with the lower tangent line of the water outlet pipe (12).

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