High-temperature heat storage and exchange device

Abstract

A high-temperature heat storage and exchange device comprises a heat storage and exchange module, a heat exchange module and a first heat release and exchange module, a first heat exchanger and a plurality of first overflow pipes are arranged in the heat storage and exchange module, and steam and fused salt flow into the heat storage and exchange module to exchange heat by means of the first heat exchanger; the fused salt subjected to heat exchange overflows to the top of the heat exchange module through a first overflow pipe, and steam subjected to heat exchange flows out of the heat storage and exchange module; a plurality of second overflow pipes are arranged in the heat exchange modules, and the fused salt overflows to the top of the next heat exchange module or the top of the first heat release heat exchange module through the second overflow pipes; a plurality of second heat exchangers which are arranged side by side are arranged in the first heat release and exchange module, the second heat exchangers are inclined coil pipes which are spirally upward, feed water or steam flows into the first heat release and exchange module to exchange heat with the fused salt by means of the second heat exchangers, and the steam after heat exchange flows out of the first heat release and exchange module. The heat storage efficiency and the heat exchange efficiency are improved by optimizing the flowing paths of steam and fused salt.

Description

Technical Field

[0001] This utility model relates to the field of heat storage and heat exchange devices, and in particular to a high-temperature heat storage and heat exchange device. Background Technology

[0002] Large-scale power storage systems can effectively address the instability of renewable energy, adjust peak and off-peak power grids, and improve the economic efficiency and stability of the power system. Currently, power grids often use thermal energy storage devices to store electrical energy. These devices typically use molten salt as the heat storage medium, converting low-cost electricity generated at night or surplus wind and solar power into high-temperature molten salt for storage. When electricity is needed, the high-temperature molten salt is fully exchanged with water to generate superheated steam, which is then used to generate electricity, thus achieving energy conservation.

[0003] Existing heat storage and heat exchange devices, such as the Chinese invention with application number CN202210608538.5 (authorization announcement number CN114838611B), include a heating unit, a high-temperature heat exchange and heat storage structure, and a reflux circulation unit. During the heat storage process, the heating unit uses high-temperature steam as a heat source to heat the heat transfer fluid. The heated heat transfer fluid enters the high-temperature heat exchange and heat storage structure through a distribution pipe. The high-temperature heat exchange and heat storage structure is assembled by stacking at least two high-temperature heat exchange and heat storage units. The heat transfer fluid in each high-temperature heat exchange and heat storage unit overflows step by step and finally reaches the reflux circulation unit to complete the heat storage of solid heat storage particles. During the heat release process, feedwater enters the reflux circulation unit and flows upward to each high-temperature heat exchange and heat storage unit in sequence, turning into high-temperature steam during the upward flow.

[0004] Although the aforementioned heat storage and heat exchange device can store and release heat, the path for high-temperature steam to store heat is relatively long. Superheated steam needs to pass through multiple heat storage and heat exchange modules sequentially before exiting, making the heat storage process slow. Similarly, the path for feedwater to enter the heat storage and heat exchange device and become high-temperature steam is also long, requiring the feedwater to pass through multiple heat release modules sequentially before exiting, thus slowing the heat release process. Therefore, the heat storage and heat release efficiency of this device is poor, affecting its operational performance. Further improvements to the high-temperature heat storage and heat exchange device are therefore necessary. Summary of the Invention

[0005] The technical problem to be solved by this utility model is to provide a high-temperature heat storage and heat exchange device that can improve heat storage efficiency and heat release efficiency, in view of the above-mentioned existing technology.

[0006] The technical solution adopted by this utility model to solve the above-mentioned technical problem is as follows: the high-temperature heat storage and heat exchange device, from top to bottom, includes a heat storage and heat exchange module, a heat exchange module, and a first heat release and heat exchange module, characterized in that:

[0007] The heat storage and heat exchange module is equipped with a first heat exchanger and multiple first overflow pipes. Steam and molten salt flow into the heat storage and heat exchange module and exchange heat with the first heat exchanger. After heat exchange, the molten salt overflows to the top of the heat exchange module through the first overflow pipes, and the steam after heat exchange flows out of the heat storage and heat exchange module.

[0008] Multiple heat exchange modules are stacked one on top of the other, and each heat exchange module is provided with multiple second overflow pipes. Molten salt overflows through the second overflow pipes to the top of the next heat exchange module or the first heat release heat exchange module.

[0009] The first heat exchange module is equipped with multiple second heat exchangers arranged side by side. The second heat exchangers are spiral upward inclined coils. Water or steam flows into the first heat exchange module and exchanges heat with molten salt through the second heat exchangers. The steam after heat exchange flows out of the first heat exchange module.

[0010] To allow steam and molten salt to flow into the heat storage module, preferably, it also includes a steam inlet pipe, a first outlet pipe, and a molten salt inlet pipe. The two ends of the first heat exchanger of the heat storage module are connected to the steam inlet pipe and the first outlet pipe, respectively. The heat storage module is also connected to the molten salt inlet pipe. The first outlet pipe and the molten salt inlet pipe are located on one side of the heat storage module, and the steam inlet pipe and the first overflow pipe are located on the other side. Low-temperature molten salt flows into the heat storage module through the molten salt inlet pipe, and steam flows into the first heat exchanger of the heat storage module through the steam inlet pipe. Because the molten salt inlet pipe and the steam inlet pipe are located on opposite sides of the heat storage module, the steam and low-temperature molten salt flow in opposite directions, further improving the heat exchange capacity of the heat storage module. The steam, cooled by the heat exchange, flows out of the heat storage module through the first outlet pipe.

[0011] To enable the high-temperature heat storage and heat exchange device to adapt to changes in the volume of molten salt, preferably, it also includes a second heat exchange module located below the first heat exchange module. The second heat exchange module contains a third heat exchanger. The first heat exchange module contains a connecting channel and multiple third overflow pipes. The molten salt in the first heat exchange module overflows into the second heat exchange module through the third overflow pipes. The two ends of the connecting channel are connected to the first and second heat exchange modules respectively. Steam after heat exchange through the third heat exchanger flows into the first heat exchange module via the connecting channel. During the operation of the high-temperature heat storage and heat exchange device, the molten salt temperature and density change, causing changes in the volume of molten salt within the unit. The volumes of the heat storage module, the heat exchange module, and the first heat exchange module remain constant, while the second heat exchange module has a larger volume, utilizing its space to accommodate changes in molten salt volume. Furthermore, the second heat exchange module also releases heat, i.e., the feedwater and the high-temperature molten salt undergo sufficient heat exchange through the third heat exchanger.

[0012] To enhance the heat exchange capacity of the second exothermic heat exchange module, preferably, a partition is provided within the second exothermic heat exchange module. The partition divides the second exothermic heat exchange module into an upper first space and a lower second space. The third heat exchanger is disposed within the second space, and the third heat exchanger is a serpentine heat exchange tube. The partition separates the third heat exchanger from the upper space (first space) within the second exothermic heat exchange module, restricting the flow of high-temperature molten salt to the second space during operation, thereby improving the heat exchange capacity of the second exothermic heat exchange module.

[0013] Furthermore, it also includes a water supply pipe and a second outflow pipe. The water supply pipe is connected to the inlet of the third heat exchanger of the second heat exchange module. The outlet of the third heat exchanger is connected to one end of a connecting channel, and the other end of the connecting channel is connected to the inlet of the second heat exchanger of the first heat exchange module. The second outflow pipe is connected to the outlet of the second heat exchanger of the first heat exchange module. Water is fed into the third heat exchanger of the second heat exchange module through the water supply pipe to exchange heat with the high-temperature molten salt. The steam generated by the third heat exchanger flows into the second heat exchanger of the first heat exchange module through the connecting channel to continue exchanging heat with the high-temperature molten salt, thereby generating superheated steam. The superheated steam flows out through the second outflow pipe. The superheated steam flowing out of the first heat exchange module can be mixed with the steam flowing out of the second heat exchange module to regulate the temperature of the outflowing steam.

[0014] To optimize the layout of the first exothermic heat exchange module, preferably, the first exothermic heat exchange module includes a water inlet pipe and a steam pipe. The water inlet pipe is located below the steam pipe. The inlet of the second heat exchanger is located at the bottom and communicates with the water inlet pipe, and the outlet of the second heat exchanger is located at the top and communicates with the steam pipe. The water inlet pipe can collect the steam flowing into the second heat exchanger and then evenly distribute it into each second heat exchanger. The steam pipe can also collect the superheated steam flowing out of each second heat exchanger. The water inlet pipe is located below the steam pipe, making the flow direction of the second heat exchanger a bottom-up path. This causes the steam in the second heat exchanger to flow in the opposite direction to the high-temperature molten salt. Therefore, the path of the second heat exchanger is adapted to the characteristics of the temperature field, which is lower at the bottom and higher at the top, thus improving the heat exchange capacity of the first exothermic heat exchange module.

[0015] Furthermore, the water inlet pipe is connected to the connecting channel, and the steam pipe is connected to the second outlet pipe. Part of the steam generated by the second heat exchange module can flow into the first heat exchange module through the connecting channel for secondary heat exchange, generating superheated steam which then flows out through the second outlet pipe. The remaining steam generated by the second heat exchange module can flow out directly. The steam generated by the second heat exchange module is then mixed with the superheated steam generated by the first heat exchange module in a certain proportion to produce steam at the temperature required by the user.

[0016] To improve the heat storage capacity of the heat storage module, preferably, the heat storage module also includes multiple baffles arranged in an alternating pattern to form a serpentine flow channel for molten salt. The first heat exchanger is a serpentine heat exchange tube arranged along the flow channel, and multiple first overflow pipes are located at the ends of the flow channel. The baffles and the serpentine heat exchange tube-shaped first heat exchanger within the heat storage module increase the flow path of molten salt and steam, allowing for sufficient heat exchange and improving the heat storage capacity of the heat storage module.

[0017] Furthermore, the first overflow pipe includes a pipe body for overflow and a guide pipe sleeved outside the pipe body. The upper end of the guide pipe is open and higher than the opening at the upper end of the pipe body. The lower end of the guide pipe is an inlet for molten salt to flow in. The inlet height of the guide pipe of each first overflow pipe is inconsistent. The heat storage and heat exchange module is also provided with multiple first overflow pipes at the end of the flow channel formed by the baffle plate. The guide pipe is sleeved outside the pipe body of the first overflow pipe. The high-temperature molten salt after heat exchange can flow into the guide pipe from the inlet of the guide pipe. Then, the high-temperature molten salt flows into the pipe body through the guide pipe, so that the high-temperature molten salt overflows downward through the first overflow pipe. Moreover, the inlet height of each first overflow pipe is different, so that the molten salt can flow evenly in the upper and lower regions of the flow cross section. That is, each layer of molten salt at the end of the flow channel can flow into the first overflow pipe through the guide pipe. Therefore, the molten salt in the heat storage and heat exchange module can flow stably, which enhances the reliability of molten salt heat exchange and improves the efficiency of molten salt heat exchange.

[0018] To improve the flexibility of the second overflow pipe's layout within the heat exchange module, preferably, the second overflow pipe includes an inner pipe, an outer pipe, and a filter box. The upper opening of the inner pipe is oblique, and the outer pipe is sleeved outside the inner pipe. The upper end of the outer pipe is open, and the lower opening of the outer pipe is an inlet for fluid to flow in. There is a gap between the outer pipe and the inner pipe. The lower end of the outer pipe is connected to the upper end of the filter box. The surface of the filter box is provided with multiple through holes for molten salt to flow in. The lower end of the inner pipe passes through the filter box and is connected to the next heat exchange module or the first exothermic heat exchange module. The second overflow pipe has an inner pipe, an outer pipe, and a filter box. The gap between the inner and outer pipes forms a channel for molten salt to flow in. Molten salt at the bottom flows in through the through holes on the surface of the filter box, then flows into the channel through the lower end of the outer pipe, and finally overflows out of the heat exchange module from the inner pipe. The flow path of the molten salt in the second overflow pipe is inverted U-shape. The inner and outer pipes can reduce the volume of the second overflow pipe, making the space occupied by the second overflow pipe in the heat exchange module smaller, and the layout of the second overflow pipe more reasonable and flexible. In addition, the overflow port of the inner pipe of the second overflow pipe is oblique, which can reduce the gradient of the overflow flow rate as the molten salt level rises. Therefore, even if the height of each inner pipe in the heat exchange module is not consistent, it can be ensured that each second overflow pipe can overflow, which improves the flexibility of the layout of the second overflow pipe in the heat exchange module.

[0019] Compared with the prior art, the advantages of this utility model are:

[0020] (1) The steam heat storage process of the high temperature heat storage heat exchange device is as follows: superheated steam enters the first heat exchanger of the heat storage heat exchange module and fully exchanges heat with low temperature molten salt. After heat exchange, the cooled steam flows out of the heat storage heat exchange module. The high temperature molten salt after heat exchange overflows to the top of the heat exchange module through the first overflow pipe. The lower temperature molten salt near the bottom of the heat exchange module overflows to the top of the next heat exchange module or the first heat release heat exchange module through the second overflow pipe. That is, the high temperature molten salt after being heated by the heat storage heat exchange module moves from top to bottom, so that the high temperature molten salt replaces the low temperature molten salt. The low temperature molten salt at the bottom of the device is transported to the heat storage heat exchange module by the molten salt pump to exchange heat with the steam, thereby shortening the steam heat storage path, making full use of the heat storage capacity of the device, and thus improving the heat storage efficiency of the high temperature heat storage heat exchange device.

[0021] (2) The heat release process of the high-temperature heat storage heat exchange device is as follows: feedwater or steam enters the second heat exchanger of the first heat release heat exchange module, and fully exchanges heat with high-temperature molten salt through multiple second heat exchangers. After generating superheated steam, the steam is discharged. The low-temperature molten salt cooled by the feedwater is transported to the heat storage heat exchange module through the molten salt pump. The low-temperature molten salt replaces the high-temperature molten salt, so that the high-temperature molten salt overflows to the top of the heat exchange module through the first overflow pipe, so that the high-temperature molten salt continuously flows to the lower module, thereby enabling the first heat release heat exchange module to continuously obtain new high-temperature molten salt, and thus enabling the first heat release heat exchange module to continuously generate steam. That is, during the heat release process, the heat exchange between the high-temperature molten salt and the feedwater or steam only occurs in the first heat release heat exchange module. The temperature field of the first heat release heat exchange module is relatively stable, which shortens the path of heat exchange between the high-temperature molten salt and the feedwater or steam to generate steam, thereby improving the heat release efficiency of the high-temperature heat storage heat exchange device. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of an embodiment of the present utility model;

[0023] Figure 2 This is a structural schematic diagram of an embodiment of the present invention from another perspective;

[0024] Figure 3 This is a schematic diagram of the heat storage and heat exchange module in an embodiment of this utility model;

[0025] Figure 4 This is a schematic diagram of the heat storage and heat exchange module in an embodiment of the present invention from another perspective (the outer shell is omitted);

[0026] Figure 5 This is a cross-sectional view of the second overflow pipe in an embodiment of the present invention;

[0027] Figure 6 This is a schematic diagram of the structure of the first heat release and heat exchange module in an embodiment of this utility model;

[0028] Figure 7 This is a schematic diagram of the structure of the third heat exchanger, water inlet pipe, and steam pipe in this embodiment of the present invention;

[0029] Figure 8 This is a schematic diagram of the structure of the second heat release and heat exchange module in an embodiment of this utility model. Detailed Implementation

[0030] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0031] like Figures 1-8 The image shown is the preferred embodiment of this utility model.

[0032] like Figure 1 and Figure 2As shown, the high-temperature heat storage heat exchange device in this embodiment includes, from top to bottom, a heat storage heat exchange module 1, a heat exchange module 2, a first heat release heat exchange module 3, and a second heat release heat exchange module 4. The high-temperature heat storage heat exchange device is also provided with a steam inlet pipe 5, a first outflow pipe 6, a molten salt inlet pipe 7, a water supply pipe 8, and a second outflow pipe 9.

[0033] like Figure 3 and Figure 4 As shown, the heat storage and heat exchange module 1 of this embodiment is provided with multiple first heat exchangers 11, multiple first overflow pipes 12, and multiple baffles 13. The multiple baffles 13 are arranged in an alternating manner to form a serpentine flow channel for the flow of molten salt. The first heat exchangers 11 are serpentine heat exchange pipes. The first heat exchangers 11 are arranged along the flow channel. Steam and molten salt flow into the heat storage and heat exchange module 1 and exchange heat with the first heat exchangers 11. The multiple first overflow pipes 12 are set at the end of the flow channel. The molten salt after heat exchange overflows to the top of the heat exchange module 2 through the first overflow pipes 12. Specifically, the first overflow pipes 12 are connected to a molten salt distributor (not shown in the figure). The porous structure of the molten salt distributor distributes the molten salt to various parts of the top of the heat exchange module 2. Furthermore, in this embodiment, the first overflow pipe 12 includes a pipe body 121 for overflow and a guide pipe 122 sleeved outside the pipe body 121. The upper end of the guide pipe 122 is open and higher than the opening at the upper end of the pipe body 121. The lower end of the guide pipe 122 is the inlet for molten salt to flow in. The inlet height of the guide pipe 122 of each first overflow pipe 12 is not consistent, so that the molten salt can flow evenly in the upper and lower regions of the flow cross section. That is, each layer of molten salt at the end of the flow channel can flow into the first overflow pipe 12 through the guide pipe 122. Therefore, the molten salt in the heat storage and heat exchange module 1 can flow stably, which enhances the reliability of molten salt heat exchange and improves the efficiency of molten salt heat exchange.

[0034] In addition, in this embodiment, the two ends of the first heat exchanger 11 of the heat storage heat exchange module 1 are connected to the steam inlet pipe 5 and the first outlet pipe 6, respectively. The heat storage heat exchange module 1 is also connected to the molten salt inlet pipe 7. The first outlet pipe 6 and the molten salt inlet pipe 7 are arranged on one side of the heat storage heat exchange module 1, and the steam inlet pipe 5 and the first overflow pipe 12 are arranged on the other side of the heat storage heat exchange module 1. Low-temperature molten salt flows into the flow channel of the heat storage heat exchange module 1 through the molten salt inlet pipe 7, and steam flows into the first heat exchanger 11 of the heat storage heat exchange module 1 through the steam inlet pipe 5. Since the molten salt inlet pipe 7 and the steam inlet pipe 5 are arranged on both sides of the heat storage heat exchange module 1, the steam and the low-temperature molten salt flow in opposite directions in the flow channel of the heat storage heat exchange module 1, which further improves the heat exchange capacity of the heat storage heat exchange module 2. The steam cooled by heat exchange flows out of the heat storage heat exchange module from the first outlet pipe 6, and the molten salt heated by heat exchange overflows downward from the first overflow pipe 12 at the end of the flow channel to the top of the heat exchange module 2.

[0035] like Figure 1 and Figure 5 As shown, in this embodiment, there are multiple heat exchange modules 2, which are stacked vertically. Each heat exchange module 2 has multiple second overflow pipes 21, through which molten salt overflows to the top of the next heat exchange module 2 or the first exothermic heat exchange module 3. The second overflow pipes 21 in this embodiment are as follows: Figure 5 As shown, it includes an inner tube 211, an outer tube 212, and a filter box 213. The upper opening of the inner tube 211 is oblique. The outer tube 212 is sleeved on the outside of the inner tube 211. The upper end of the outer tube 212 is open, and the lower opening of the outer tube 212 is an inlet for fluid to flow in. There is a gap between the outer tube 212 and the inner tube 211. The lower end of the outer tube 212 is connected to the upper end of the filter box 213. The surface of the filter box 213 is provided with multiple through holes for molten salt to flow in. The lower end of the inner tube 211 passes through the filter box 213 and is connected to a heat exchange module 2 or a first exothermic heat exchange module 3. A gap exists between the inner tube 211 and the outer tube 212, forming a channel for molten salt to flow in. The through-holes on the filter box 213 are filter holes, allowing only molten salt to flow in; other solid heat storage medium particles cannot flow in. The molten salt at the bottom flows in through the through-holes on the surface of the filter box 213, then flows into the channel through the lower end of the outer tube 212, and finally overflows from the inner tube 211 out of the heat exchange module 2. The flow path of the molten salt within the second overflow pipe 21 is inverted U-shaped. The inner tube 211 and the outer tube 212 can... This reduces the volume of the second overflow pipe 21, making it occupy less space within the heat exchange module 2, and allowing for a more reasonable and flexible layout. Furthermore, the overflow port of the inner tube 211 of the second overflow pipe 21 is angled, which reduces the gradient of overflow flow as the molten salt level rises. Therefore, even if the height of each inner tube 211 within the heat exchange module 2 is inconsistent, it can still ensure that each second overflow pipe 21 can overflow, thus improving the flexibility of the layout of the second overflow pipe 21 within the heat exchange module 2.

[0036] like Figure 6 and Figure 7As shown, the first heat exchange module 3 of this embodiment includes a second heat exchanger 31, a connecting channel 32, a third overflow pipe 33, a water inlet pipe 34, and a steam pipe 35. Multiple second heat exchangers 31 are arranged side-by-side laterally within the first heat exchange module 3. Each second heat exchanger 31 is a spirally upward-facing inclined coil. Water or steam flows into the first heat exchange module 3 and exchanges heat with the molten salt through the second heat exchangers 31. The steam after heat exchange flows out of the first heat exchange module 3. Both the water inlet pipe 34 and the steam pipe 35 are arranged laterally. The water inlet pipe 34 is located below the steam pipe 35 and is connected to the connecting channel 32. The steam pipe 35 is connected to the second outflow pipe 9. The inlet of the second heat exchanger 31 is located at the bottom and is connected to the water inlet pipe 34. 4. The outlet of the second heat exchanger 31 is located at the top and connected to the steam pipe 35. The water inlet pipe 34 allows steam from the connecting channel 32 to flow in and then flow evenly into each second heat exchanger 31. The flow direction of the second heat exchanger 31 is from bottom to top. Therefore, the steam in the second heat exchanger 31 flows upward in a spiral, causing the steam in the second heat exchanger 31 to flow in the opposite direction to the high-temperature molten salt. The path of the second heat exchanger 31 is adapted to the characteristics of the temperature field, which is lower at the bottom and higher at the top, so that the heat exchange capacity of the first heat exchange module 3 is better. The superheated steam after heat exchange in the second heat exchanger 31 flows into the steam pipe 35. The steam pipe 35 can collect the superheated steam flowing out of each second heat exchanger 31. The collected superheated steam then flows out through the second outflow pipe 9. In addition, the molten salt in the first heat exchange module 3 overflows into the second heat exchange module 4 through the third overflow pipe 33. The two ends of the connecting channel 32 are connected to the first heat exchange module 3 and the second heat exchange module 4 respectively. The steam after heat exchange through the third heat exchanger 41 flows into the first heat exchange module 3 through the connecting channel 32.

[0037] like Figure 1 , Figure 2 and Figure 8As shown, in this embodiment, the second exothermic heat exchange module 4 is located below the first exothermic heat exchange module 3. The second exothermic heat exchange module 4 has a larger volume, and the space of the second exothermic heat exchange module 4 is used to adapt to the change in the volume of molten salt. The second heat exchange module 4 in this embodiment is provided with a partition (not shown in the figure), a third heat exchanger 41 and a second baffle 42. The partition divides the second heat exchange module 4 into a first space at the top and a second space at the bottom. The third heat exchanger 41 and the second baffle 42 are arranged in the second space. The third heat exchanger 41 is a serpentine heat exchange tube. The water supply pipe 8 is connected to the inlet of the third heat exchanger 41. The outlet of the third heat exchanger 41 is connected to one end of the connecting channel 32. The other end of the connecting channel 32 is connected to the inlet of the second heat exchanger 31 of the first heat exchange module 3. The partition separates the third heat exchanger 41 and the second baffle 42 from the upper space (first space) in the second heat exchange module 4, so that the high-temperature molten salt can only flow in the second space when working, thereby improving the heat exchange capacity of the second heat exchange module 4. The second heat exchange module 4 also releases heat, that is, the water supply and the high-temperature molten salt are fully exchanged through the third heat exchanger 41.

[0038] The working process of the high-temperature thermal storage heat exchange device in this embodiment is as follows:

[0039] The steam heat storage process is as follows: Superheated steam flows from the steam inlet pipe 5 into the first heat exchanger 11 of the heat storage module 1. Low-temperature molten salt is lifted by the molten salt pump and flows from the molten salt inlet pipe 7 into the flow channel of the heat storage module 1. The superheated steam and the low-temperature molten salt flow in opposite directions in the flow channel of the heat storage module 1, allowing for sufficient heat exchange between the superheated steam and the low-temperature molten salt. The steam cooled by the heat exchange flows out of the heat storage module from the first outlet pipe 6. The high-temperature molten salt heated by the heat exchange overflows downward from the first overflow pipe 12 at the end of the flow channel to the top of the heat exchange module 2. Then, the low-temperature molten salt at the bottom of the heat exchange module 2 is replaced by the high-temperature molten salt at the top and flows into the top of the heat exchange module 2, thereby heating the solid heat storage medium in the heat exchange module 2. The particles cause the low-temperature molten salt at the bottom to overflow downwards through the second overflow pipe 21 to the top of the next heat exchange module 2 or the first heat-releasing heat exchange module 3; then, the low-temperature molten salt at the bottom of the first heat-releasing heat exchange module 3 is replaced by the high-temperature molten salt at the top of the first heat-releasing heat exchange module 3 by means of the third overflow pipe 33, and the low-temperature molten salt overflows into the second heat-releasing heat exchange module 4; finally, the low-temperature molten salt in the second heat-releasing heat exchange module 4 flows out and then flows into the heat storage heat exchange module 1 through the molten salt pump and the molten salt inlet pipe 7. During this process, the solid heat storage medium particles in the first heat-releasing heat exchange module 3 and the second heat-releasing heat exchange module 4 are also heated and their temperature rises until the temperature of the molten salt flowing out of the second heat-releasing heat exchange module 4 rises to a certain level, thus completing the heat storage process of the high-temperature heat storage heat exchange device.

[0040] The process of generating steam through heat release is as follows: Water flows through water supply pipe 8 into the third heat exchanger 41 of the second heat release module 4, where it exchanges heat with high-temperature molten salt. The resulting steam flows out of the second heat release module 4 and then through connecting channel 32 into the inlet pipe 34 of the first heat release module 3. The inlet pipe 34 directs the steam to each second heat exchanger 31, allowing the steam to undergo secondary heat exchange with the high-temperature molten salt, thus generating superheated steam. The superheated steam from each second heat exchanger 31 is then collected through steam pipe 35 and flows out of the high-temperature heat storage device through the second outlet pipe 9. The molten salt cooled after heat exchange in the first heat release module 3 overflows downwards through the third overflow pipe 33. The cooled molten salt, after heat exchange in the second heat exchange module 4, flows out and is then pumped by a molten salt pump into the flow channel of the heat storage module 1 through the molten salt inlet pipe 7. The low-temperature molten salt replaces the high-temperature molten salt in the heat storage module 1, causing the high-temperature molten salt to overflow through the first overflow pipe 12 to the top of the heat exchange module 2. The molten salt in each heat exchange module 2 undergoes the same replacement, causing the high-temperature molten salt to continuously flow to the lower modules, thereby continuously providing the first heat exchanger 3 with new high-temperature molten salt, and enabling the first heat exchanger 3 to continuously generate superheated steam. As the process continues, the temperature of the molten salt in the first heat exchanger 3 gradually decreases, and the heat release ends when the steam temperature at the outlet of the first heat exchanger 3 is lower than the required temperature.

[0041] The second heat exchange module 4 in this embodiment can also be provided with an outflow channel for the steam after heat exchange to flow out. The steam after heat exchange in the third heat exchanger 41 in the second heat exchange module 4 can partially flow into the first heat exchange module 3 through the connecting channel 32 for secondary heat exchange. The remaining steam can flow out of the second heat exchange module 4 through the outflow channel. The superheated steam after secondary heat exchange in the first heat exchange module 3 flows out of the first heat exchange module 3 through the second outflow pipe 9. The superheated steam flowing out of the first heat exchange module 3 and the steam flowing out of the second heat exchange module 4 can be mixed in a certain proportion outside the high-temperature heat storage heat exchange device to obtain superheated steam at the temperature required by the user for power generation.

[0042] In addition, the heat storage and heat exchange module 1 in this embodiment can be replaced with an electric heater. During the heat storage process, the low-temperature molten salt is heated by the electric heater and then injected into the molten salt distributor through the overflow pipe, overflowing to the top of the heat exchange module 2. The rest of the process is the same.

Claims

1. A high-temperature heat storage and heat exchange device, comprising, from top to bottom, a heat storage and heat exchange module (1), a heat exchange module (2), and a first heat release and heat exchange module (3), characterized in that: The heat storage and heat exchange module (1) is provided with a first heat exchanger (11) and a plurality of first overflow pipes (12). Steam and molten salt flow into the heat storage and heat exchange module (1) and exchange heat with the first heat exchanger (11). The molten salt after heat exchange overflows to the top of the heat exchange module (2) through the first overflow pipes (12), and the steam after heat exchange flows out of the heat storage and heat exchange module (1). Multiple heat exchange modules (2) are stacked one on top of the other. Each heat exchange module (2) is provided with multiple second overflow pipes (21). Molten salt overflows through the second overflow pipes (21) to the top of the next heat exchange module (2) or the first heat release heat exchange module (3). The first heat exchange module (3) is provided with multiple second heat exchangers (31) arranged in parallel. The second heat exchanger (31) is a spiral upward inclined coil. Water or steam flows into the first heat exchange module (3) and exchanges heat with molten salt through the second heat exchanger (31). The steam after heat exchange flows out of the first heat exchange module (3).

2. The high-temperature heat storage and heat exchange device according to claim 1, characterized in that: It also includes a steam inlet pipe (5), a first outlet pipe (6) and a molten salt inlet pipe (7). The two ends of the first heat exchanger (11) of the heat storage heat exchange module (1) are connected to the steam inlet pipe (5) and the first outlet pipe (6) respectively. The heat storage heat exchange module (1) is also connected to the molten salt inlet pipe (7). The first outlet pipe (6) and the molten salt inlet pipe (7) are located on one side of the heat storage heat exchange module (1), and the steam inlet pipe (5) and the first overflow pipe (12) are located on the other side of the heat storage heat exchange module (1).

3. The high-temperature heat storage and heat exchange device according to claim 1, characterized in that: It also includes a second heat exchange module (4) located below the first heat exchange module (3). The second heat exchange module (4) is provided with a third heat exchanger (41). The first heat exchange module (3) is provided with a connecting channel (32) and a plurality of third overflow pipes (33). The molten salt in the first heat exchange module (3) overflows into the second heat exchange module (4) through the third overflow pipes (33). The two ends of the connecting channel (32) are respectively connected to the first heat exchange module (3) and the second heat exchange module (4). The steam after heat exchange through the third heat exchanger (41) flows into the first heat exchange module (3) through the connecting channel (32).

4. The high-temperature heat storage and heat exchange device according to claim 3, characterized in that: The second heat exchange module (4) is provided with a partition, which divides the second heat exchange module (4) into a first space located at the top and a second space located at the bottom. The third heat exchanger (41) is located in the second space and is a serpentine heat exchange tube.

5. The high-temperature heat storage and heat exchange device according to claim 3, characterized in that: It also includes a water supply pipe (8) and a second outflow pipe (9). The water supply pipe (8) is connected to the inlet of the third heat exchanger (41) of the second heat exchange module (4). The outlet of the third heat exchanger (41) is connected to one end of the connecting channel (32). The other end of the connecting channel (32) is connected to the inlet of the second heat exchanger (31) of the first heat exchange module (3). The second outflow pipe (9) is connected to the outlet of the second heat exchanger (31) of the first heat exchange module (3).

6. The high-temperature heat storage and heat exchange device according to claim 5, characterized in that: The first heat exchange module (3) includes a water inlet pipe (34) and a steam pipe (35). The water inlet pipe (34) is located below the steam pipe (35). The inlet of the second heat exchanger (31) is located at the bottom and is connected to the water inlet pipe (34). The outlet of the second heat exchanger (31) is located at the top and is connected to the steam pipe (35).

7. The high-temperature heat storage and heat exchange device according to claim 6, characterized in that: The water inlet pipe (34) is connected to the connecting channel (32), and the steam pipe (35) is connected to the second outflow pipe (9).

8. The high-temperature heat storage and heat exchange device according to claim 1, characterized in that: The heat storage and heat exchange module (1) is also provided with multiple baffles (13). The multiple baffles (13) are arranged in an alternating manner to form a serpentine flow channel for the flow of molten salt. The first heat exchanger (11) is a serpentine heat exchange tube. The first heat exchanger (11) is arranged along the flow channel. Multiple first overflow pipes (12) are set at the end of the flow channel.

9. The high-temperature thermal storage heat exchange device according to claim 1, characterized in that: The first overflow pipe (12) includes a pipe body (121) for overflow and a guide pipe (122) sleeved outside the pipe body (121). The upper end of the guide pipe (122) is open and higher than the opening at the upper end of the pipe body (121). The lower end of the guide pipe (122) is an inlet for molten salt to flow in. The inlet height of the guide pipe (122) of each first overflow pipe (12) is not consistent.

10. The high-temperature heat storage and heat exchange device according to claim 1, characterized in that: The second overflow pipe (21) includes an inner pipe (211), an outer pipe (212), and a filter box (213). The upper opening of the inner pipe (211) is oblique. The outer pipe (212) is sleeved on the outside of the inner pipe (211). The upper end of the outer pipe (212) is open. The lower opening of the outer pipe (212) is an inlet for fluid to flow in. There is a gap between the outer pipe (212) and the inner pipe (211). The lower end of the outer pipe (212) is connected to the upper end of the filter box (213). The surface of the filter box (213) is provided with multiple through holes for molten salt to flow in. The lower end of the inner pipe (211) passes through the filter box (213) and is connected to a heat exchange module (2) or a first exothermic heat exchange module (3).

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