Compact molten salt heat exchange device

Abstract

The utility model provides a compact type fused salt heat exchange device which comprises a fused salt pump assembly and a heat exchange assembly, the fused salt pump assembly is communicated with the heat exchange assembly, the heat exchange assembly comprises a heat exchange unit, the heat exchange unit comprises a spiral heat exchange tube bundle, the spiral heat exchange tube bundle is provided with a plurality of spiral heat exchange tubes, and the spiral heat exchange tubes are arranged in a winding mode. The spiral heat exchange tubes in the spiral heat exchange tube bundle are arranged in a winding mode, the heat exchange area can be effectively increased, so that the heat exchange power is improved, compared with a traditional straight tube structure, the turbulent flow effect can be formed when fused salt flows through at the low flow speed, and the formation of turbulent flow is beneficial to enhancing the heat transfer coefficient; and the temperature gradient problem possibly caused by non-uniform flow is reduced. In addition, the parallel structural design of the multiple spiral heat exchange pipe assemblies can be more compact in structure, the occupied area of heat exchange equipment can be reduced, an efficient and compact integrated structure is provided for the molten salt heat exchange device, and the spiral heat exchange device is suitable for being applied to a molten salt reactor system with limited space.

Description

Technical Field

[0001] This utility model relates to the field of molten salt driven heat exchange, and in particular to a compact molten salt heat exchange device. Background Technology

[0002] A molten salt reactor is an advanced fourth-generation nuclear reactor type. Its molten salt loop system is responsible for the core functions of supplying liquid fuel and transferring nuclear fission energy (thermal energy) to the reactor cycle. The molten salt reactor loop system consists of molten salt heat exchangers, molten salt pumps, and piping. Molten salt heat exchangers typically employ straight-tube or U-tube heat exchange structures, offering high reliability but relatively low heat exchange efficiency. As heat exchange power increases, conventional heat exchangers cannot be designed with compact dimensions, affecting the overall structural dimensions and layout. Utility Model Content

[0003] The technical problem to be solved by this utility model is to overcome the relatively low heat exchange efficiency and structural defects of existing molten salt heat exchange devices, and to provide a compact molten salt heat exchange device.

[0004] The present invention solves the above-mentioned technical problems through the following technical solution:

[0005] A compact molten salt heat exchange device includes a molten salt pump assembly and a heat exchange assembly. The molten salt pump assembly is connected to the heat exchange assembly. The heat exchange assembly includes a heat exchange unit, which includes a spiral heat exchange tube bundle. The spiral heat exchange tube bundle has a plurality of spiral heat exchange tubes wound together.

[0006] In this scheme, heat transfer is achieved through the connection of the molten salt pump assembly and the heat exchange assembly. The heat exchange unit, as a crucial structure for heat exchange operation, includes a spiral heat exchange tube bundle. Several spiral heat exchange tubes within the bundle are wound together, effectively increasing the heat exchange area and thus enhancing the heat exchange power. Compared to traditional straight tube structures, the spiral heat exchange tube structure creates turbulence when the molten salt flows through at a lower velocity, thereby increasing the heat transfer rate. The formation of turbulence helps enhance the heat transfer coefficient and reduces temperature gradient problems that may be caused by uneven flow. Furthermore, the wound design of the spiral heat exchange tube bundle allows for a more compact structure. Compared to straight tubes or U-shaped tubes, it significantly reduces the height of the heat exchanger and the overall volume of the equipment, improving space utilization. This not only reduces the footprint of the heat exchange equipment but also provides a highly efficient and compact integrated structure for the molten salt heat exchange device, suitable for application in space-constrained molten salt reactor systems.

[0007] Preferably, the heat exchange assembly further includes a heat exchange shell, and the heat exchange unit is disposed inside the heat exchange shell. The heat exchange shell includes an inlet nozzle and an outlet nozzle, and the heat exchange unit includes a molten salt inlet and a molten salt outlet. The molten salt inlet is connected to the inlet nozzle to allow molten salt to be introduced into the heat exchange unit so that the molten salt contacts the outer wall of the spiral heat exchange tube. The molten salt outlet is connected to the outlet nozzle to form a flow path for the molten salt.

[0008] In this design, inlet and outlet nozzles are installed, enabling a controllable flow path for the molten salt within the heat exchange assembly. After the heat exchange process, the molten salt can be smoothly discharged, forming a complete molten salt flow loop. This structural design improves the uniformity and continuity of the molten salt flow path, thereby optimizing heat exchange efficiency. The molten salt inlet is connected to the inlet nozzle, allowing precise control over the molten salt flowing in from the inlet nozzle into the heat exchange unit and ensuring full contact with the outer wall of the spiral heat exchange tube.

[0009] Preferably, the heat exchange unit includes at least one first heat exchange unit and at least one second heat exchange unit. Both the first and second heat exchange units include a spiral heat exchange tube bundle. The outer wall of the second heat exchange unit is fitted to the outer wall of the first heat exchange unit. The molten salt inlet of the first heat exchange unit is connected to the molten salt inlet of the second heat exchange unit so that molten salt can flow into both units. The molten salt outlet of the first heat exchange unit is connected to the molten salt outlet of the second heat exchange unit so that molten salt can flow out from both units to the outside.

[0010] In this design, the outer walls of the first and second heat exchange units are fitted together to minimize leakage and heat loss caused by gaps between them. The molten salt inlets of the first and second heat exchange units are connected, allowing molten salt to enter both units simultaneously. This simultaneous heat exchange across multiple units significantly improves heat exchange efficiency. Furthermore, the fitted outer walls of the first and second heat exchange units enhance thermal conductivity and improve overall structural compactness, making the entire heat exchange device smaller and easier to integrate. The molten salt outlets of the first and second heat exchange units are connected, ensuring smooth discharge of the high-temperature molten salt after heat exchange, forming a complete flow loop. This reduces the risk of localized overheating, improves the uniformity of molten salt heat exchange and the continuity of flow, thereby significantly enhancing the system's stability and safety.

[0011] Preferably, the first heat exchange unit further includes a first outer sleeve and a first inner sleeve, and a spiral heat exchange tube bundle is located between the first outer sleeve and the first inner sleeve. Multiple spiral heat exchange tubes are spaced apart along the radial direction of the first heat exchange unit and spirally arranged along the axial direction of the first heat exchange unit. The gap between the spiral heat exchange tube bundle and the first inner sleeve and the first outer sleeve is used to form a flow path for part of the molten salt.

[0012] And / or, the second heat exchange unit further includes a second inner sleeve and a second outer sleeve, a spiral heat exchange tube bundle is located between the second inner sleeve and the second outer sleeve, a plurality of spiral heat exchange tubes are spaced apart along the radial direction of the second heat exchange unit and spirally arranged along the axial direction of the first heat exchange unit; the gap between the spiral heat exchange tube bundle and the second inner sleeve and the second outer sleeve is used to form a flow path for part of the molten salt.

[0013] In this design, a spiral heat exchange tube bundle is placed in the space between the first outer sleeve and the first inner sleeve to form an independent first heat exchange unit. This optimizes the flow path of the molten salt. Multiple spiral heat exchange tubes are spaced apart in the radial direction and spirally arranged in the axial direction, allowing the molten salt to generate sufficient turbulence in the spiral path as it flows through the outer wall of the tube bundle, further enhancing heat transfer efficiency. This design structure enables the molten salt to flow uniformly between the spiral heat exchange tubes, thereby further improving the heat exchange effect. In addition, by adjusting the axial spacing and spiral angle, the molten salt flow rate and heat exchange effect can be further adjusted according to actual needs.

[0014] Similarly, the second heat exchange unit, by setting up a second inner and outer jacket tube and a spiral heat exchange tube bundle, also forms a flow path for molten salt in the space between the second inner and outer jacket tubes. This design of the two heat exchange units can jointly achieve uniform molten salt distribution and multi-stage parallel heat exchange, ensuring the high efficiency and stability of the molten salt heat exchange process, and also optimizing space utilization, providing strong support for compact and efficient molten salt heat exchange devices.

[0015] Preferably, the heat exchange assembly further includes an upper heat exchange tube sheet and a lower heat exchange tube sheet. There are gaps between the two ends of the first outer sleeve and the upper and lower heat exchange tube sheets to form a molten salt inlet and a molten salt outlet, respectively. The first inner sleeve abuts against the upper and lower heat exchange tube sheets to isolate the chamber of the first inner sleeve from the molten salt. The molten salt inlet and the molten salt outlet are both arranged along the circumference of the first outer sleeve. The molten salt inlet is connected to the primary side molten salt outlet of the molten salt pump assembly through an inlet nozzle to introduce molten salt into the first heat exchange unit.

[0016] And / or, along the circumferential direction of the second outer sleeve, there are gaps between the two ends of the second outer sleeve and the upper heat exchange tube sheet and the lower heat exchange tube sheet to communicate with the molten salt inlet and molten salt outlet of the first heat exchange unit, and the second inner sleeve abuts against the upper heat exchange tube sheet and the lower heat exchange tube sheet to seal the chamber of the second inner sleeve.

[0017] In this design, the flow path and heat exchange process of the molten salt are further optimized through the structural design of the upper and lower heat exchange tube sheets. The molten salt inlet and outlet are arranged circumferentially along the first outer jacket tube, allowing the molten salt to enter and exit the first heat exchange unit uniformly in the circumferential direction. This ensures uniform distribution of the molten salt throughout the entire heat exchange tube bundle, avoiding localized overheating or uneven temperature. The circumferentially arranged inlet and outlet design, connected to the molten salt outlet of the molten salt pump assembly, ensures the uniformity and stability of the flow rate of molten salt from the pump assembly into the first heat exchange unit, improving heat exchange efficiency. Furthermore, the molten salt makes full contact with the outer wall of the spiral heat exchange tubes in the flow path formed by the gaps, achieving continuous and efficient heat transfer. The outer tube of the second heat exchange unit also has gaps between its two ends and the upper and lower heat exchange tube sheets, which can also ensure that the molten salt can flow smoothly and continuously in the two-stage heat exchange unit; the two ends of the second inner tube abut against the upper and lower heat exchange tube sheets, sealing the chamber of the inner tube, which helps the directional flow of molten salt and prevents unnecessary leakage in the chamber, thereby maintaining the required heat exchange power.

[0018] Preferably, the heat exchange assembly further includes an upper cover plate and a lower end cap, wherein the upper cover plate and the upper heat exchange tube sheet form an upper water chamber for storing the heat exchange medium to be exchanged after heat exchange;

[0019] The lower end cap and the lower heat exchange tube sheet form a lower water chamber for storing the heat exchange medium to be exchanged before heat exchange. The upper water chamber and the lower water chamber are located on the side of the upper heat exchange tube sheet and the lower heat exchange tube sheet away from the heat exchange unit, respectively. The two ends of the first heat exchange unit and the second heat exchange unit are connected to the upper water chamber and the lower water chamber through the upper heat exchange tube sheet and the lower heat exchange tube sheet, respectively.

[0020] In this design, by setting an upper cover plate and a lower end cap, the heat exchange assembly forms an upper water chamber and a lower water chamber on the side of the upper and lower heat exchange tube sheets opposite to the heat exchange units, respectively. The upper water chamber stores the heat exchange medium after heat exchange, while the lower water chamber stores the heat exchange medium before it enters the heat exchange assembly, effectively achieving stable flow and stratified management of the heat exchange medium. The upper water chamber is connected to the upper ends of the first and second heat exchange units through the upper heat exchange tube sheet, and the lower water chamber is connected to the lower ends of the first and second heat exchange units through the lower heat exchange tube sheet. This allows the heat exchange medium to flow into the lower water chamber, gradually transferring heat through the spiral heat exchange tube bundle of the heat exchange unit, and finally reaching the upper water chamber. This flow path creates a bottom-up flow within the heat exchange assembly, contributing to stability during the heat exchange process. The upper and lower water chambers play a significant role in fluid distribution and flow guidance, improving the heat transfer efficiency of the heat exchange medium. Meanwhile, this layout further optimizes the compactness of the equipment, providing higher space utilization for the design of heat exchange components. Overall, the synergy between the water chamber design and the spiral heat exchange tube bundle ensures the efficiency and stability of the fluid flow path within the system, making it suitable for high-efficiency molten salt heat exchange applications.

[0021] Preferably, both the upper and lower heat exchange tube sheets are provided with a number of molten salt through holes, which are connected to the spiral heat exchange tube bundles of the first and second heat exchange units, so that the heat exchange medium to be exchanged in the lower water chamber enters the upper water chamber through the spiral heat exchange tube bundles to form a flow path for part of the heat exchange medium.

[0022] In this design, several molten salt through-holes are provided on the upper and lower heat exchanger tube sheets, allowing the spiral heat exchanger tube bundles of the first and second heat exchange units to communicate with these through-holes. This forms a flow path for the heat exchange medium within the heat exchange device. The heat exchange medium in the lower water chamber can enter the spiral heat exchanger tube bundle through these molten salt through-holes, and after heat transfer, flow into the upper water chamber from the tube bundle outlet. The path of the heat exchange medium through the spiral heat exchanger tube bundle is fully extended, significantly increasing the contact area between the medium and the tube wall. The high-temperature molten salt located outside the tube wall can fully heat the medium inside the tube bundle, resulting in more uniform heating and a more efficient heat exchange effect. The molten salt through-holes on the upper and lower heat exchanger tube sheets communicate with the corresponding spiral heat exchanger tube ends, ensuring that the heated medium is evenly distributed within each spiral heat exchanger tube, avoiding flow deviations and localized heat accumulation, and improving the heat exchange uniformity and temperature control of the equipment.

[0023] Preferably, the heat exchange unit further includes at least one heat exchange inlet pipe, which passes through the upper water chamber, the first heat exchange unit and the lower heat exchange tube sheet in sequence, and the outer wall of the heat exchange inlet pipe is in contact with the first inner sleeve, and the heat exchange inlet pipe is connected to the lower water chamber.

[0024] And / or, the heat exchange unit also includes at least one heat exchange outlet pipe, with its two ends connected to the upper water chamber and the outside, respectively.

[0025] In this design, the fluid flow direction and path are more directional, avoiding leakage or uneven flow in the heat exchange unit. One end of the heat exchange outlet pipe connects to the upper water chamber, while the other end directly connects to the outside, allowing the heat-exchanged medium to flow smoothly out of the heat exchange unit, forming a continuous flow path from inlet to outlet. The heat-exchanged medium can then be smoothly discharged from the equipment through the outlet pipe. Furthermore, the piping design between the molten salt pump and the heat exchanger has been simplified, making the heat exchange system more compact and efficient. This structure reduces the space occupied by the equipment, helping to save costs and improve system efficiency.

[0026] Preferably, a gap is provided between the heat exchange inlet pipe and the upper cover plate and the upper heat exchange tube sheet, and / or, a gap is provided between the heat exchange inlet pipe and the lower heat exchange tube sheet.

[0027] In this design, the gap between the heat exchange inlet pipe and the upper and lower heat exchange tube sheets forms a buffer zone, which can effectively absorb the thermal expansion deviation caused by the temperature difference between the high-temperature molten salt and the medium to be heated, thereby improving the structural stability of the heat exchange system and extending the service life of the equipment.

[0028] Preferably, the heat exchange assembly further includes several corrugated pipes, at least one corrugated pipe is sleeved on the heat exchange inlet pipe and its two ends abut against the upper cover plate and the upper heat exchange tube plate, and at least one corrugated pipe is sleeved on the heat exchange inlet pipe and its one end abuts against the lower heat exchange tube plate.

[0029] In this design, the bellows exhibits excellent elasticity, adapting to thermal expansion and contraction caused by temperature changes during heat exchange. Positioned outside the heat exchange inlet pipe, the bellows provides flexible compensation space, reducing stress concentration caused by thermal expansion and contraction, and preventing deformation or damage to the inlet pipe. After contact with the upper cover plate, upper heat exchange tube sheet, and lower heat exchange tube sheet, the bellows forms a good seal, effectively preventing cross-leakage between the heat exchange medium and molten salt, ensuring the safety and purity of the heat exchange process. The bellows also possess excellent fatigue resistance to temperature and pressure fluctuations, effectively delaying fatigue damage caused by long-term thermal cycling. Therefore, in high-temperature molten salt heat exchange applications, the bellows extends the service life of the equipment, enabling the system to operate stably for longer periods.

[0030] Preferably, there are six first heat exchange units and one second heat exchange unit. The six first heat exchange units are arranged around the second heat exchange unit, and the outer walls of the six first heat exchange units are sequentially attached to each other.

[0031] In this design, by arranging six first heat exchange units around the second heat exchange unit, the overall heat exchange area is significantly increased. The surrounding arrangement of the six first heat exchange units ensures a smoother flow path for the fluid within each heat exchange unit, allowing the fluid to flow more evenly through each unit, thus achieving better heat exchange performance and improving the overall efficiency of the heat exchange system. Furthermore, the surrounding arrangement of the first heat exchange units enhances the space utilization of the entire heat exchange assembly. This compact design not only reduces the space occupied by the equipment but also helps to lower the system's construction and maintenance costs.

[0032] The positive and progressive effects of this utility model are as follows:

[0033] Heat transfer is achieved through the connection between the molten salt pump assembly and the heat exchange assembly. The heat exchange unit, a crucial structure for heat exchange operation, comprises a spiral heat exchange tube bundle. The spiral heat exchange tubes within this bundle are wound together, effectively increasing the heat exchange area and thus enhancing heat exchange power. Compared to the straight or U-shaped tube structures commonly used in molten salt reactors, the spiral heat exchange tube structure can achieve turbulence at lower molten salt flow velocities. Turbulence contributes to a higher heat transfer coefficient. Furthermore, the winding design of the spiral heat exchange tube bundle allows for a more compact structure, reducing the overall height and volume of the equipment and improving space utilization. This not only reduces the footprint of the heat exchange equipment but also provides a highly efficient and compact integrated structure for molten salt heat exchange devices, making it suitable for application in space-constrained molten salt reactor systems. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the structure of a compact molten salt heat exchanger, an example of this utility model;

[0035] Figure 2 This is a schematic diagram of the heat exchange core of a heat exchange component according to an example of this utility model;

[0036] Figure 3 This is a schematic diagram of the structure of the second heat exchange unit in an embodiment of this utility model.

[0037] Explanation of reference numerals in the attached figures:

[0038] 100 Molten Salt Heat Exchanger

[0039] 1100 heat exchange unit

[0040] 111 First heat exchange unit

[0041] 1111 First Outer Tube

[0042] 1112 First Inner Sleeve

[0043] 112 Second Heat Exchange Unit

[0044] 1121 Second outer tube

[0045] 1122 Second Inner Bushing

[0046] 1123 Upper sealing plate

[0047] 1124 lower sealing plate

[0048] 1110 spiral heat exchanger tube

[0049] 113 Heat Exchanger Shell

[0050] 1131 Imported Nozzle

[0051] 1132 Outlet Nozzle

[0052] 1101 Molten Salt Import

[0053] 1102 Molten Salt Export

[0054] 114 Upper heat exchanger tube sheet

[0055] 115 Lower heat exchanger tube sheet

[0056] 116 Upper Cover Plate

[0057] 117 lower head

[0058] 1160 upper water chamber

[0059] 1170 lower water chamber

[0060] 118 heat exchanger inlet pipe

[0061] 119 heat exchanger outlet pipe

[0062] 1130 corrugated pipe

[0063] 120 Molten Salt Pump Assembly

[0064] 121 Molten Salt Pump Inlet Detailed Implementation

[0065] The present invention will be described more clearly and completely below with reference to the accompanying drawings, using a preferred embodiment.

[0066] One embodiment of this utility model provides a molten salt heat exchanger 100, which is a compact molten salt heat exchanger. For example... Figure 1-3 As shown, it includes a molten salt pump assembly 120 and a heat exchange assembly. The molten salt pump assembly 120 is connected to the heat exchange assembly. The heat exchange assembly includes a heat exchange unit 1100. The heat exchange unit 1100 includes a spiral heat exchange tube bundle. The spiral heat exchange tube bundle has a plurality of spiral heat exchange tubes 1110, which are wound together.

[0067] In this embodiment, heat transfer is achieved through the connection between the molten salt pump assembly 120 and the heat exchange assembly. The heat exchange unit 1100, as a crucial structure for heat exchange, includes a spiral heat exchange tube bundle. Several spiral heat exchange tubes 1110 within the bundle are wound together, effectively increasing the heat exchange area and thus enhancing the heat exchange power. Compared to traditional straight tube structures, the spiral heat exchange tube 1110 structure creates turbulence when the molten salt flows through at a lower velocity, thereby increasing the heat transfer rate. The formation of turbulence also helps to enhance the heat transfer coefficient. Furthermore, the winding design of the spiral heat exchange tube bundle allows for a more compact structure, reducing the overall size of the equipment. This not only reduces the footprint of the heat exchange equipment but also provides a highly efficient and compact integrated structure for the molten salt heat exchange device 100, making it suitable for application in space-constrained molten salt reactor systems.

[0068] like Figure 1-3 As shown, the heat exchange assembly also includes a heat exchange housing 113, and a heat exchange unit 1100 is disposed inside the heat exchange housing 113. The heat exchange housing 113 includes an inlet nozzle 1131 and an outlet nozzle 1132. The heat exchange unit 1100 includes a molten salt inlet 1101 and a molten salt outlet 1102. The molten salt inlet 1101 is connected to the inlet nozzle 1131 to allow molten salt to be introduced into the heat exchange unit 1100 so that the molten salt contacts the outer wall of the spiral heat exchange tube 1110. The molten salt outlet 1102 is connected to the outlet nozzle 1132 to form a flow path for the molten salt. By setting up inlet nozzle 1131 and outlet nozzle 1132, a controllable flow path for molten salt is achieved within the heat exchange component. After the heat exchange process, the molten salt can be smoothly discharged, forming a complete molten salt flow loop. This structural design can improve the uniformity and continuity of the molten salt flow path, thereby optimizing heat exchange efficiency and further enhancing the stability and safety of the heat exchange system. It provides efficient and reliable technical support for the entire device. Molten salt inlet 1101 is connected to inlet nozzle 1131, which can precisely control the molten salt flowing in from inlet nozzle 1131 into heat exchange unit 1100 to fully contact the outer wall of spiral heat exchange tube 1110, achieving full heat exchange and thus improving heat exchange efficiency.

[0069] like Figure 1 and Figure 3As shown, the heat exchange unit 1100 includes at least one first heat exchange unit 111 and at least one second heat exchange unit 112. Both the first heat exchange unit 111 and the second heat exchange unit 112 include a spiral heat exchange tube bundle. The outer wall of the second heat exchange unit 112 is fitted to the outer wall of the first heat exchange unit 111. The molten salt inlet 1101 of the first heat exchange unit 111 is connected to the molten salt inlet 1101 of the second heat exchange unit 112 so that molten salt can flow into the first heat exchange unit 111 and the second heat exchange unit 112. The molten salt outlet 1102 of the first heat exchange unit 111 is connected to the molten salt outlet 1102 of the second heat exchange unit 112 so that molten salt can flow out from the first heat exchange unit 111 and the second heat exchange unit 112 to the outside. The outer walls of the first heat exchange unit 111 and the second heat exchange unit 112 are fitted together. The molten salt inlet 1101 of the first heat exchange unit 111 is connected to the molten salt inlet 1101 of the second heat exchange unit 112, allowing molten salt to enter both heat exchange units 1100 simultaneously. This structure not only enhances the heat conduction effect but also improves the overall compactness of the structure, making the entire heat exchange device more compact and easier to integrate. The molten salt outlets 1102 of the first heat exchange unit 111 and the second heat exchange unit 112 are connected, allowing the molten salt located in the first heat exchange unit 111 and the second heat exchange unit 112 to be smoothly discharged from the heat exchange device after completing heat exchange, forming a complete flow loop. This improves the uniformity of molten salt heat exchange and the continuity of flow, thereby significantly improving the stability and safety of the system.

[0070] like Figure 1-3 As shown, the first heat exchange unit 111 also includes a first outer sleeve 1111 and a first inner sleeve 1112. A spiral heat exchange tube bundle is located between the first outer sleeve 1111 and the first inner sleeve 1112. Multiple spiral heat exchange tubes 1110 are spaced apart in the radial direction of the first heat exchange unit 111 and spirally arranged in the axial direction of the first heat exchange unit 111. The gap between the spiral heat exchange tube bundle and the first inner sleeve 1112 and the first outer sleeve 1111 is used to form a flow path for part of the molten salt. The spiral heat exchange tube bundle is placed in the space between the first outer sleeve 1111 and the first inner sleeve 1112 to form an independent first heat exchange unit 111, which optimizes the flow path of the molten salt. The multiple spiral heat exchange tubes 1110 are spaced apart in the radial direction and spirally arranged in the axial direction, so that the molten salt can generate sufficient turbulence in the spiral path when flowing through the outer wall of the tube bundle, which further enhances the heat transfer efficiency. This design structure allows the gap between the spiral heat exchange tube bundle and the first inner and outer sleeves to form a flow path for the molten salt, ensuring that the molten salt can flow evenly between each spiral heat exchange tube 1110, and enabling the molten salt to maintain continuous and efficient contact with the outer wall of the spiral heat exchange tube 1110, thereby further improving the heat exchange effect. In addition, by adjusting the spacing and spiral angle in the axial direction, the molten salt flow rate and heat exchange effect can be further adjusted according to actual needs.

[0071] like Figure 3 As shown, the second heat exchange unit 112 also includes a second inner sleeve 1122 and a second outer sleeve 1121. A spiral heat exchange tube bundle is located between the second inner sleeve 1122 and the second outer sleeve 1121. Multiple spiral heat exchange tubes 1110 are spaced apart along the radial direction of the second heat exchange unit 112 and spirally arranged along the axial direction of the first heat exchange unit 111. The gap between the spiral heat exchange tube bundle and the second inner sleeve 1122 and the second outer sleeve 1121 is used to form a flow path for part of the molten salt. By setting the second inner and outer sleeves and the spiral heat exchange tube bundle, the space between the second inner and outer sleeves of the second heat exchange unit 112 also forms a flow path for the molten salt. This design of the two heat exchange units 1100 can jointly achieve uniform molten salt distribution and multi-stage parallel heat exchange, ensuring the high efficiency and stability of the molten salt heat exchange process, and also optimizing space utilization, providing strong support for the compact and efficient molten salt heat exchange device 100.

[0072] like Figure 1-3 As shown, the heat exchange assembly also includes an upper heat exchange tube sheet 114 and a lower heat exchange tube sheet 115. There are gaps between the two ends of the first outer sleeve 1111 and the upper heat exchange tube sheet 114 and the lower heat exchange tube sheet 115 to form a molten salt inlet 1101 and a molten salt outlet 1102, respectively. The first inner sleeve 1112 abuts against the upper heat exchange tube sheet 114 and the lower heat exchange tube sheet 115 to seal the chamber of the first inner sleeve 1112 and isolate the chamber of the first inner sleeve 1112 from the molten salt. Molten salt inlet 1101 and molten salt outlet 1102 are both arranged circumferentially along the first outer sleeve 1111. Molten salt inlet 1101 is connected to the primary side molten salt outlet 1102 of molten salt pump assembly 120 through inlet nozzle 1131 to introduce molten salt into the first heat exchange unit 111. Along the circumferential direction of the second outer sleeve 1121, there are gaps between the two ends of the second outer sleeve 1121 and the upper heat exchange tube plate 114 and the lower heat exchange tube plate 115 to communicate with the molten salt inlet 1101 and molten salt outlet 1102 of the first heat exchange unit 111. The second inner sleeve 1122 abuts against the upper heat exchange tube plate 114 and the lower heat exchange tube plate 115 to seal the chamber of the second inner sleeve 1122.

[0073] The structural design of the upper heat exchanger tube sheet 114 and the lower heat exchanger tube sheet 115 optimizes the flow path and heat exchange process of the molten salt. The molten salt inlet 1101 and molten salt outlet 1102 are arranged circumferentially along the first outer sleeve 1111, allowing the molten salt to enter and exit the first heat exchange unit 111 uniformly in the circumferential direction. This ensures the uniform distribution of the molten salt throughout the heat exchanger tube bundle and avoids local overheating or uneven temperature. The circumferentially arranged inlet and outlet design, connected to the primary side molten salt outlet 1102 of the molten salt pump assembly 120, ensures the uniformity and stability of the flow rate of the molten salt as it flows from the pump assembly into the first heat exchange unit 111, improving heat exchange efficiency. Furthermore, the molten salt makes full contact with the outer wall of the spiral heat exchanger tube 1110 in the flow path formed by the gaps, achieving continuous and efficient heat transfer and enhancing the overall heat exchange effect of the device. The outer sleeve of the second heat exchange unit 112 also maintains gaps between its two ends and the upper and lower heat exchange tube sheets 115, which can also ensure that the molten salt can flow smoothly and continuously in parallel in the two-stage heat exchange units 1100; the two ends of the second inner sleeve 1122 abut against the upper and lower heat exchange tube sheets 115, sealing the chamber of the inner sleeve, which helps the directional flow of the molten salt and prevents unnecessary leakage in the chamber, thereby maintaining the heat exchange power required by the molten salt.

[0074] like Figure 1 and Figure 2As shown, the heat exchange assembly also includes an upper cover plate 116 and a lower end cap 117. The upper cover plate 116 and the upper heat exchange tube plate 114 form an upper water chamber 1160 for storing the medium to be exchanged after heat exchange. The lower end cap 117 and the lower heat exchange tube plate 115 form a lower water chamber 1170 for storing the medium to be exchanged before heat exchange. The upper water chamber 1160 and the lower water chamber 1170 are located on the side of the upper heat exchange tube plate 114 and the lower heat exchange tube plate 115 away from the heat exchange unit 1100, respectively. The two ends of the first heat exchange unit 111 and the second heat exchange unit 112 are connected to the upper water chamber 1160 and the lower water chamber 1170 through the upper heat exchange tube plate 114 and the lower heat exchange tube plate 115, respectively. The upper water chamber 1160 stores the heat exchange medium after heat exchange, while the lower water chamber 1170 stores the heat exchange medium before it enters the heat exchange assembly, effectively achieving stable flow and stratified management of the heat exchange medium. The upper water chamber 1160 is connected to the upper ends of the first heat exchange unit 111 and the second heat exchange unit 112 via an upper heat exchange tube sheet 114, and the lower water chamber 1170 is connected to the lower ends of the first heat exchange unit 111 and the second heat exchange unit 112 via a lower heat exchange tube sheet 115. In this way, the heat exchange medium can flow into the lower water chamber 1170, and through the spiral heat exchange tube bundle of the heat exchange unit 1100, gradually transfer heat until it reaches the upper water chamber 1160. This flow path creates a bottom-up flow of the medium within the heat exchange assembly, contributing to stability during the heat exchange process and establishing a natural circulation trend of the molten salt. The upper water chamber 1160 and the lower water chamber 1170 play a significant role in fluid storage and flow guidance. Meanwhile, this layout further optimizes the compactness of the equipment, providing higher space utilization for the design of heat exchange components. Overall, the synergy between the water chamber design and the spiral heat exchange tube bundle ensures the efficiency and stability of the fluid flow path within the system, making it suitable for high-efficiency molten salt heat exchange applications.

[0075] like Figure 1 and Figure 3As shown, both the upper heat exchange tube plate 114 and the lower heat exchange tube plate 115 are provided with several molten salt through holes (not shown in the figure). These molten salt through holes communicate with the spiral heat exchange tube bundles of the first heat exchange unit 111 and the second heat exchange unit 112, allowing the heat exchange medium in the lower water chamber 1170 to enter the upper water chamber 1160 through the spiral heat exchange tube bundles, thus forming a flow path for part of the heat exchange medium. The spiral heat exchange tubes 1110 are connected to the molten salt through holes, thereby forming a flow path for the heat exchange medium in the heat exchange device. The heat exchange medium in the lower water chamber 1170 can enter the spiral heat exchange tube bundle through these molten salt through holes, and after the heat transfer process, flow into the upper water chamber 1160 from the tube bundle outlet. The path of the heat exchange medium through the spiral heat exchange tube bundle is sufficiently extended, significantly increasing the contact area between the medium and the tube wall. The high-temperature molten salt located outside the tube wall can fully heat the medium located inside the tube bundle, resulting in a more uniform heating effect and achieving a more efficient heat exchange effect. The design of the molten salt through-holes ensures a stable flow path for the heat exchange medium from the lower water chamber 1170 through the spiral heat exchange tube bundle into the upper water chamber 1160. This makes the entire heat exchange process more stable. The molten salt through-holes on the upper and lower heat exchange tube plates 115 are connected to the ends of the corresponding spiral heat exchange tubes 1110, allowing the heated medium to be evenly distributed within each spiral heat exchange tube 1110, avoiding flow deviation and local heat accumulation, improving the heat exchange uniformity and temperature control effect of the equipment. Directly connecting the fluid path with the spiral heat exchange tube bundle enables effective flow and switching of the medium in different areas. The heating molten salt and the heated medium flow through the external and internal pipes of the spiral heat exchange tubes 1110 respectively, which not only optimizes the structural compactness of the device but also reduces the additional piping requirements and improves the space utilization of the equipment.

[0076] like Figure 1 As shown, the heat exchange unit 1100 also includes at least one heat exchange inlet pipe 118, which passes sequentially through the upper water chamber 1160, the first heat exchange unit 111, and the lower heat exchange tube sheet 115. The outer wall of the heat exchange inlet pipe 118 is fitted with the first inner sleeve 1112, and the heat exchange inlet pipe 118 is connected to the lower water chamber 1170. The heat exchange unit 1100 also includes at least one heat exchange outlet pipe 119, with its two ends connected to the upper water chamber 1160 and the outside, respectively. The flow direction and path of the fluid are more directional, avoiding leakage or uneven flow in the heat exchange unit. One end of the heat exchange outlet pipe 119 is connected to the upper water chamber 1160, and the other end is directly connected to the outside, allowing the heat-exchanged medium to flow smoothly out of the heat exchange unit 1100, forming a continuous flow path from the inlet to the outlet. The heat-exchanged medium can be smoothly discharged from the equipment through the outlet pipe. The piping design between the molten salt pump and the heat exchanger has been further simplified, making the heat exchange system more compact and efficient. This structure reduces the space occupied by the equipment, helping to save costs and improve system efficiency.

[0077] A gap (not shown in the figure) is provided between the heat exchange inlet pipe 118 and the upper cover plate 116 and the upper heat exchange tube plate 114, and / or, a gap is provided between the heat exchange inlet pipe 118 and the lower heat exchange tube plate 115. The gap design between the heat exchange inlet pipe 118 and the upper and lower heat exchange tube plates 115 can form a buffer zone, which can effectively absorb the thermal expansion deviation caused by the temperature difference between the high-temperature molten salt and the medium to be heated, thereby improving the structural stability of the heat exchange system and extending the service life of the equipment.

[0078] like Figure 1 As shown, the heat exchange assembly also includes several corrugated pipes 1130. At least one corrugated pipe 1130 is sleeved on the heat exchange inlet pipe 118, and its two ends abut against the upper cover plate 116 and the upper heat exchange tube plate 114. At least one corrugated pipe 1130 is sleeved on the heat exchange inlet pipe 118, and its one end abuts against the lower heat exchange tube plate 115. The bellows 1130 possesses excellent elastic properties, enabling it to adapt to thermal expansion and contraction caused by temperature changes during heat exchange. Located outside the heat exchange inlet pipe 118, the bellows 1130 provides flexible compensation space, reducing stress concentration in the inlet pipe 118 due to thermal expansion and contraction, thus preventing deformation or damage to the heat exchange pipeline. After the bellows 1130 abuts against the upper cover plate 116, upper heat exchange tube plate 114, and lower heat exchange tube plate 115, it forms a good seal, effectively preventing cross-leakage between the heat exchange medium and molten salt, ensuring the safety and purity of the heat exchange process, and further improving the system's heat exchange efficiency. The elastic structure of the bellows 1130 alleviates thermal stress and extends the system's service life. The bellows 1130 also exhibits excellent fatigue resistance in the face of temperature and pressure fluctuations, effectively delaying fatigue damage to equipment caused by long-term thermal cycling. Therefore, in high-temperature molten salt heat exchange applications, the use of corrugated pipe 1130 extends the service life of the equipment, enabling the system to operate stably for a longer period of time.

[0079] like Figure 1 and Figure 3 As shown, the second heat exchange unit 112 also includes an upper sealing plate 1123 and a lower sealing plate 1124 disposed within the second inner sleeve 1122. The upper sealing plate 1123 and the lower sealing plate 1124 are positioned between the molten salt inlet 1101 and the molten salt outlet 1102. The sealing plates prevent high-temperature molten salt from flowing into the cavity formed by the inner sleeve of the second heat exchange unit 112, and this isolation design improves the sealing performance of the heat exchange unit 1100.

[0080] In this embodiment, six first heat exchange units 111 and one second heat exchange unit 112 are configured. The six first heat exchange units 111 are arranged around the second heat exchange unit 112, and the outer walls of the six first heat exchange units 111 are sequentially attached to each other. By arranging the six first heat exchange units 111 around the second heat exchange unit 112, the overall heat exchange surface area is significantly increased. The surrounding arrangement of the six first heat exchange units 111 makes the flow path of the fluid within the heat exchange unit 1100 smoother, allowing the fluid to flow more evenly through each heat exchange unit 1100, thereby achieving better heat exchange effect and improving the overall working efficiency of the heat exchange system. The surrounding arrangement of the six first heat exchange units 111 effectively reduces the heat load of a single heat exchange unit 1100 by evenly distributing the heat input. The surrounding arrangement of the first heat exchange units 111 around the second heat exchange unit 112 also improves the space utilization of the entire heat exchange assembly. This compact design not only reduces the space occupied by the equipment but also helps to reduce the construction and maintenance costs of the system.

[0081] In other alternative embodiments, the first heat exchange unit 111 and the second heat exchange unit 112 can also be set to other quantities according to actual needs, as long as the heat exchange work described above can be met.

[0082] During heat exchange operation, the primary side molten salt (i.e., heated molten salt) enters through the molten salt pump inlet 121 of the molten salt pump assembly 120, and then drives the molten salt through the nozzle 1131 of the primary side molten salt inlet 1101 into the housing of the heat exchange assembly. It then flows into the molten salt inlet 1101 of the heat exchange unit 1100, flows circumferentially along the heat exchange assembly, enters the interior of each first heat exchange unit 111 and the second heat exchange unit 112, flows in the gap between the spiral heat exchange tube 1110 and the first inner sleeve 1112 and the second outer sleeve 1121 for heat exchange, and finally flows out from the molten salt outlet 1102. It then converges through the gap between each heat exchange unit 1100 and the housing into the chamber between the lower water chamber 1170 and the lower end cap of the housing, and flows out from the nozzle 1132 of the primary side molten salt outlet 1102. The secondary side molten salt (i.e. the medium to be heated) enters the lower water chamber 1170 through the heat exchange inlet pipe 118, then flows upward through the lower heat exchange tube plate 115 into the spiral heat exchange tube 1110. After exchanging heat with the primary side molten salt, it enters the upper water chamber 1160 through the upper heat exchange tube plate 114 and finally flows upward out of the heat exchanger through the heat exchange outlet pipe 119.

[0083] While specific embodiments of this utility model have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of this utility model is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of this utility model, but all such changes and modifications fall within the scope of protection of this utility model.

Claims

1. A compact molten salt heat exchanger, comprising a molten salt pump assembly and a heat exchange assembly, wherein the molten salt pump assembly is connected to the heat exchange assembly, characterized in that, The heat exchange assembly includes a heat exchange unit, the heat exchange unit includes a spiral heat exchange tube bundle, the spiral heat exchange tube bundle has a plurality of spiral heat exchange tubes, and the plurality of spiral heat exchange tubes are wound together. The heat exchange assembly further includes a heat exchange shell, and the heat exchange unit is disposed inside the heat exchange shell. The heat exchange shell includes an inlet nozzle and an outlet nozzle. The heat exchange unit includes a molten salt inlet and a molten salt outlet. The molten salt inlet is connected to the inlet nozzle to allow molten salt to be introduced into the heat exchange unit so that the molten salt contacts the outer wall of the spiral heat exchange tube. The molten salt outlet is connected to the outlet nozzle to form a flow path for the molten salt. The heat exchange unit includes at least one first heat exchange unit and at least one second heat exchange unit. Both the first heat exchange unit and the second heat exchange unit include the spiral heat exchange tube bundle. The outer wall of the second heat exchange unit is fitted to the outer wall of the first heat exchange unit. The molten salt inlet of the first heat exchange unit is connected to the molten salt inlet of the second heat exchange unit so that the molten salt can flow into the first heat exchange unit and the second heat exchange unit. The molten salt outlet of the first heat exchange unit is connected to the molten salt outlet of the second heat exchange unit so that the molten salt can flow out from the first heat exchange unit and the second heat exchange unit to the outside.

2. The compact molten salt heat exchanger as described in claim 1, characterized in that, The first heat exchange unit further includes a first outer sleeve and a first inner sleeve. The spiral heat exchange tube bundle is located between the first outer sleeve and the first inner sleeve. A plurality of spiral heat exchange tubes are spaced apart along the radial direction of the first heat exchange unit and spirally arranged along the axial direction of the first heat exchange unit. The gap between the spiral heat exchange tube bundle and the first inner sleeve and the first outer sleeve is used to form a flow path for part of the molten salt. And / or, the second heat exchange unit further includes a second inner sleeve and a second outer sleeve, the spiral heat exchange tube bundle is located between the second inner sleeve and the second outer sleeve, a plurality of the spiral heat exchange tubes are spaced apart along the radial direction of the second heat exchange unit and spirally arranged along the axial direction of the first heat exchange unit; the gap between the spiral heat exchange tube bundle and the second inner sleeve and the second outer sleeve is used to form a flow path for part of the molten salt.

3. The compact molten salt heat exchanger as described in claim 2, characterized in that, The heat exchange assembly further includes an upper heat exchange tube sheet and a lower heat exchange tube sheet. There are gaps between the two ends of the first outer sleeve and the upper and lower heat exchange tube sheets to form the molten salt inlet and the molten salt outlet, respectively. The first inner sleeve abuts against the upper and lower heat exchange tube sheets to isolate the chamber of the first inner sleeve from the molten salt. The molten salt inlet and the molten salt outlet are both arranged along the circumference of the first outer sleeve. The molten salt inlet is connected to the primary side molten salt outlet of the molten salt pump assembly through the inlet nozzle to introduce the molten salt into the first heat exchange unit.

4. The compact molten salt heat exchanger as described in claim 3, characterized in that, Along the circumferential direction of the second outer sleeve, there are gaps between the two ends of the second outer sleeve and the upper heat exchange tube sheet and the lower heat exchange tube sheet to communicate with the molten salt inlet and the molten salt outlet of the first heat exchange unit. The second inner sleeve abuts against the upper heat exchange tube sheet and the lower heat exchange tube sheet to seal the chamber of the second inner sleeve.

5. The compact molten salt heat exchanger as described in claim 3 or 4, characterized in that, The heat exchange assembly further includes an upper cover plate and a lower end cap. The upper cover plate and the upper heat exchange tube sheet form an upper water chamber for storing the medium to be exchanged after heat exchange. The lower end cap and the lower heat exchange tube sheet form a lower water chamber for storing the medium to be exchanged before heat exchange. The upper water chamber and the lower water chamber are respectively located on the side of the upper heat exchange tube sheet and the lower heat exchange tube sheet away from the heat exchange unit. The two ends of the first heat exchange unit and the second heat exchange unit are respectively connected to the upper water chamber and the lower water chamber through the upper heat exchange tube sheet and the lower heat exchange tube sheet.

6. The compact molten salt heat exchanger as described in claim 5, characterized in that, Both the upper heat exchange tube sheet and the lower heat exchange tube sheet are provided with a plurality of molten salt through holes. The molten salt through holes are connected to the spiral heat exchange tube bundles of the first heat exchange unit and the second heat exchange unit, so that the heat exchange medium to be exchanged in the lower water chamber enters the upper water chamber through the spiral heat exchange tube bundles to form a flow path for part of the heat exchange medium.

7. The compact molten salt heat exchanger as described in claim 5, characterized in that, The heat exchange unit further includes at least one heat exchange inlet pipe, which passes through the upper water chamber, the first heat exchange unit and the lower heat exchange tube sheet in sequence, and the outer wall of the heat exchange inlet pipe is in contact with a portion of the first inner sleeve. The heat exchange inlet pipe is connected to the lower water chamber. And / or, the heat exchange unit further includes at least one heat exchange outlet pipe, the two ends of which are respectively connected to the upper water chamber and the outside.

8. The compact molten salt heat exchanger as described in claim 7, characterized in that, A gap is provided between the heat exchange inlet pipe and the upper cover plate and the upper heat exchange tube sheet, and / or a gap is provided between the heat exchange inlet pipe and the lower heat exchange tube sheet.

9. The compact molten salt heat exchanger as described in claim 8, characterized in that, The heat exchange assembly also includes several corrugated pipes, at least one of which is sleeved on the heat exchange inlet pipe and its two ends abut against the upper cover plate and the upper heat exchange tube plate, and at least one of which is sleeved on the heat exchange inlet pipe and its one end abuts against the lower heat exchange tube plate.

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