A molten salt energy storage system

Abstract

The application relates to the field of molten salt energy storage technology and discloses a molten salt energy storage system which comprises a low-temperature molten salt tank, a high-temperature molten salt tank, a molten salt electric heater connected with an electric power system, the low-temperature molten salt tank and the high-temperature molten salt tank being communicated with the molten salt electric heater, a steam generator, the high-temperature molten salt tank being communicated with a tube pass of the steam generator, high-temperature molten salt medium in the high-temperature molten salt tank flowing to the tube pass of the steam generator, one end of the tube pass of the steam generator away from the high-temperature molten salt tank being communicated with the low-temperature molten salt tank, and a heat exchange mechanism for circulating water supply to the steam generator, steam generated by heat exchange between circulating water in the steam generator and the high-temperature molten salt medium entering the heat exchange mechanism, and the heat exchange mechanism heating heat supply water of a user heat end by steam. The application can utilize off-peak electricity in an energy storage mode, reduces heating cost without increasing the burden of electricity peak period.

Description

Technical Field

[0001] This application relates to the field of molten salt energy storage technology, and in particular to a molten salt energy storage system. Background Technology

[0002] Hot water heating systems use hot water as the heat transfer medium and are commonly used in residential buildings for indoor heating. Traditional hot water heating systems mostly use coal combustion as the heat source, but the combustion process produces a lot of pollutants, which can easily pollute the atmospheric environment.

[0003] Currently, solar water heaters have become a common source of heat energy. However, their heating capacity drops significantly during cloudy or rainy weather. To compensate for this, electric heating is now added to solar water heaters. However, the electric heating operates during off-peak hours, which increases the burden on the power system and can easily lead to power shortages and power outages during peak hours.

[0004] Off-peak electricity refers to electricity used during periods after peak electricity consumption. Off-peak electricity has a lower price and offers higher economic benefits without increasing the electricity burden during peak periods. Therefore, how to utilize off-peak electricity has become an important issue. Summary of the Invention

[0005] To alleviate the burden on the power system during peak electricity demand periods and improve the utilization rate of off-peak electricity, this application provides a molten salt energy storage system.

[0006] This application provides a molten salt energy storage system, which adopts the following technical solution: A molten salt energy storage system, comprising: Low-temperature molten salt tank, used to hold low-temperature molten salt media; High-temperature molten salt tank, used to hold high-temperature molten salt media; A molten salt electric heater is connected to a power system, which supplies power to the molten salt electric heater. Both the low-temperature molten salt tank and the high-temperature molten salt tank are connected to the molten salt electric heater. The low-temperature molten salt medium in the low-temperature molten salt tank is pumped into the high-temperature molten salt tank after passing through the molten salt electric heater. A steam generator, wherein the high-temperature molten salt tank is connected to the tube side of the steam generator, the high-temperature molten salt medium inside the high-temperature molten salt tank flows to the tube side of the steam generator, and the end of the tube side of the steam generator away from the high-temperature molten salt tank is connected to the low-temperature molten salt tank; A heat exchange mechanism is used to circulate water to a steam generator. The steam generated by the heat exchange between the circulating water and the high-temperature molten salt medium in the steam generator will enter the heat exchange mechanism, which will heat the hot water supplied to the user's heating end.

[0007] By adopting the above technical solution, during off-peak electricity demand periods, the low-temperature molten salt medium in the low-temperature molten salt tank is pumped to the molten salt electric heater. Off-peak electricity is used to electrically heat the low-temperature molten salt medium. After absorbing energy, the low-temperature molten salt medium forms a high-temperature molten salt medium, which is then pumped back to the high-temperature molten salt tank for storage, thus storing electrical energy. During peak electricity demand periods, the high-temperature molten salt medium in the high-temperature molten salt tank is pumped to the tube side of the steam generator. Simultaneously, the heat exchange mechanism pumps circulating water into the steam generator. The circulating water and the high-temperature molten salt medium exchange heat in the steam generator, vaporizing the circulating water to form steam, which then enters the heat exchange mechanism. The steam then heats the hot water supplied to users, providing heating. By utilizing off-peak electricity through energy storage, heating costs are reduced without increasing the burden during peak electricity demand periods.

[0008] Preferably, a low-temperature supply pipe is connected between the low-temperature molten salt tank and the molten salt electric heater, and a first molten salt pump is installed on the low-temperature supply pipe; a high-temperature reflux pipe is connected between the molten salt electric heater and the high-temperature molten salt tank; a high-temperature supply pipe is connected between the high-temperature molten salt tank and the tube side of the steam generator, and a second molten salt pump is installed on the high-temperature supply pipe; a low-temperature reflux pipe is connected between the tube side of the steam generator and the low-temperature molten salt tank.

[0009] By adopting the above technical solution, the first molten salt pump is started to extract the low-temperature molten salt medium in the low-temperature molten salt tank, and then pump it into the molten salt electric heater. After being electrically heated, it can flow into the high-temperature molten salt tank. Then, the second molten salt pump is used to apply power to the high-temperature molten salt medium, so that the high-temperature molten salt medium can be extracted, thereby realizing the circulation of the high-temperature molten salt medium and the low-temperature molten salt medium.

[0010] Preferably, the heat exchange mechanism includes a heat exchanger and a first water tank. Both ends of the heat exchanger are connected to circulation pipes. The two circulation pipes are respectively connected to the inlet and outlet of the user's heating end. The first water tank is connected to the steam generator. The end of the steam generator away from the first water tank is connected to the tube side of the heat exchanger, and the end of the heat exchanger tube side away from the steam generator is connected to the first water tank.

[0011] By adopting the above technical solution, the steam generator heats the circulating water to generate steam, and then the steam enters the tube side of the heat exchanger. The hot water supplied by the user enters the heat exchanger and exchanges heat with the steam to raise its temperature, thereby heating the hot water. Then the steam condenses and flows back to the first water tank, waiting to continue the circulation.

[0012] Preferably, a second water tank is provided on one side of the first water tank, and an electric heating tube is provided in the second water tank. The electric heating tube is connected to a power system, and the power system supplies power to the electric heating tube. Each circulation pipe is connected to two branch pipes, one of which is connected to the heat exchanger and the other is connected to the second water tank. Each branch pipe is provided with a first control valve.

[0013] By adopting the above technical solution, energy loss is inevitable during the process of storing off-peak electricity using molten salt. Therefore, during peak electricity consumption periods, the circulation pipes are connected to the heat exchanger to utilize the energy stored in the molten salt. During off-peak electricity consumption periods, the two circulation pipes are connected to the second water tank through branch pipes, and the off-peak electricity is used to directly heat the hot water in the second water tank. The hot water is then circulated to the user's heating end through the circulation pipes, thus realizing the direct utilization of off-peak electricity and reducing energy loss.

[0014] Preferably, the low-temperature molten salt tank is connected to the second water tank via a first connecting pipe, and a third molten salt pump is installed on the first connecting pipe; the high-temperature molten salt tank is connected to the second water tank via a second connecting pipe, and a fourth molten salt pump is installed on the second connecting pipe.

[0015] By adopting the above technical solution, both the low-temperature molten salt tank and the high-temperature molten salt tank are connected to the second water tank. During the long-term use of the molten salt energy storage system, when the low-temperature molten salt tank or the high-temperature molten salt tank is damaged, the hot water in the second water tank is drained, and then the third or fourth molten salt pump is started to pump the molten salt medium in the low-temperature molten salt tank or the high-temperature molten salt tank to the second water tank for storage, which facilitates the timely transfer of the molten salt medium.

[0016] Preferably, the ends of the low-temperature supply pipe and the low-temperature return pipe near the low-temperature molten salt tank are both connected to a first three-way valve, and each of the two ports of the first three-way valve is connected to a low-temperature diversion pipe, one of which is connected to the low-temperature molten salt tank and the other is connected to the second water tank. The high-temperature reflux pipe and the high-temperature supply pipe are both connected to a second three-way valve at the end near the high-temperature molten salt tank. Both ports of the second three-way valve are connected to high-temperature diversion pipes. One of the high-temperature diversion pipes is connected to the high-temperature molten salt tank, and the other high-temperature diversion pipe is connected to the low-temperature molten salt tank.

[0017] By adopting the above technical solution, when the low-temperature molten salt tank is damaged and the low-temperature molten salt medium is pumped to the second water tank, the first three-way valve is controlled to connect both the low-temperature supply pipe and the low-temperature return pipe to the low-temperature diversion pipe extending into the second water tank, so that the molten salt energy storage system can form a loop and continue to operate. Similarly, when the high-temperature molten salt tank is damaged, the second three-way valve is controlled to connect both the high-temperature return pipe and the high-temperature supply pipe to the second water tank, so as to realize the operation of the molten salt energy storage system, reduce the possibility of molten salt energy storage system shutdown, and ensure the continuous efficiency of the molten salt energy storage system.

[0018] Preferably, a partition box is provided inside the second water tank, and an opening and closing mechanism is provided on the partition box. The opening and closing mechanism is used to control the opening and closing of the partition box. When the opening and closing mechanism drives the partition box to open, the partition box is connected to the interior of the second water tank. The second connecting pipe extends into the second water tank and then passes through the partition box. The low-temperature distribution pipe connected to the low-temperature supply pipe extends into the second water tank and then passes through the partition box.

[0019] By adopting the above technical solution, both the low-temperature branch pipe and the second connecting pipe of the low-temperature supply pipe are extended into the isolation box. When the second water tank is needed for circulating energy storage, the isolation box is opened, allowing both the low-temperature branch pipe and the second connecting pipe to connect with the second water tank. When the low-temperature supply pipe is transporting the low-temperature molten salt medium, if the temperature of the molten salt medium is too low, it will cause blockage of the second supply pipe. At this time, the second connecting pipe draws the high-temperature molten salt medium from the high-temperature molten salt tank into the isolation box. At the same time, the first three-way valve on the low-temperature supply pipe controls the low-temperature supply pipe to alternately connect with the two low-temperature branch pipes, so that the low-temperature molten salt medium and the high-temperature molten salt medium in the isolation box are drawn alternately. This allows the high-temperature molten salt medium to neutralize the low-temperature molten salt medium, increasing the temperature of the low-temperature molten salt medium and reducing the possibility of the low-temperature molten salt medium blocking the low-temperature supply pipe.

[0020] Preferably, a communication port is provided on one side of the partition box, and the opening and closing mechanism includes an electric push cylinder and a sealing plate. The sealing plate passes through the side wall of the second water tank and is slidably connected to the second water tank. The second water tank is slidably connected to the partition box, and the sealing plate is used to block the communication port.

[0021] By adopting the above technical solution, the opening and closing of the partition box can be controlled by using an electric pusher cylinder to drive the sliding of the sealing plate. When it is necessary to connect the partition box with the second water tank, the electric pusher cylinder can push the sealing plate to slide outward.

[0022] Preferably, the bottom of the second water tank is connected to a drain pipe, and the drain pipe is equipped with an on / off valve.

[0023] By adopting the above technical solution and opening the on / off valve, the hot water in the second water tank can be directly discharged from the second water tank, thereby improving the rate and timeliness of hot water discharge from the second water tank.

[0024] In summary, this application includes at least the following beneficial technical effects: 1. During off-peak electricity consumption periods, the system utilizes off-peak electricity to electrically heat and store energy in a low-temperature molten salt medium. During peak electricity consumption periods, the high-temperature molten salt medium in the high-temperature molten salt tank is pumped into the tube side of the steam generator. Simultaneously, the heat exchange mechanism pumps circulating water into the steam generator. The circulating water and the high-temperature molten salt medium exchange heat in the steam generator, and the circulating water vaporizes to form steam, which then enters the heat exchange mechanism. The steam then heats the hot water supplied to users to provide heating. By utilizing off-peak electricity through energy storage, heating costs are reduced without increasing the burden during peak electricity consumption periods. 2. By setting up a second water tank, during off-peak electricity periods, two circulation pipes are connected to the second water tank through branch pipes, using off-peak electricity to directly heat the hot water in the second water tank, and then circulating it to the user's heating end through the circulation pipes, thus realizing the direct use of off-peak electricity and reducing energy loss. 3. By connecting both the low-temperature molten salt tank and the high-temperature molten salt tank to the second water tank, when either the low-temperature molten salt tank or the high-temperature molten salt tank is damaged during long-term use of the molten salt energy storage system, the hot water in the second water tank is drained, and then the third or fourth molten salt pump is started to pump the molten salt medium in the low-temperature molten salt tank or the high-temperature molten salt tank to the second water tank for storage, which facilitates timely transfer of the molten salt medium. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall structure of an embodiment of this application; Figure 2 This is a schematic diagram of the heat exchange mechanism in the embodiments of this application; Figure 3 This is a schematic diagram of the structure of the second water tank in the embodiments of this application; Figure 4 This is a schematic diagram of the internal structure of the second water tank in an embodiment of this application; Figure 5 This is a schematic diagram of the opening and closing mechanism in the embodiments of this application.

[0026] Reference numerals: 100, Low-temperature molten salt tank; 110, Low-temperature supply pipe; 120, Low-temperature reflux pipe; 130, First molten salt pump; 140, Second molten salt valve; 150, First three-way valve; 160, Low-temperature diversion pipe; 200, High-temperature molten salt tank; 210, High-temperature reflux pipe; 220, High-temperature supply pipe; 230, First molten salt valve; 240, Second molten salt pump; 250, Second three-way valve; 260, High-temperature diversion pipe; 300, Molten salt electric heater; 400, Steam generator; 500, Heat exchange mechanism; 510, First water... 520. Water pump pipe; 530. Feed water pump; 540. Heat exchanger; 550. Steam pipe; 560. Return water pipe; 570. Return water valve; 600. Circulation pipe; 610. Circulation water pump; 620. Branch pipe; 630. First control valve; 700. Second water tank; 710. Drain pipe; 720. On / off valve; 730. First connecting pipe; 731. Third molten salt pump; 740. Second connecting pipe; 741. Fourth molten salt pump; 800. Isolation box; 810. Opening and closing mechanism; 811. Electric push cylinder; 812. Sealing plate. Detailed Implementation

[0027] The following is in conjunction with the appendix Figure 1-5 This application will be described in further detail.

[0028] This application discloses a molten salt energy storage system.

[0029] Reference Figure 1 and Figure 2 A molten salt energy storage system includes a cryogenic molten salt tank 100 and a high-temperature molten salt tank 200, with a molten salt electric heater 300 disposed between the cryogenic molten salt tank 100 and the high-temperature molten salt tank 200. The cryogenic molten salt tank 100 is connected to a cryogenic supply pipe 110, with one end of the cryogenic supply pipe 110 away from the cryogenic molten salt tank 100 connected to the molten salt electric heater 300. A first molten salt pump 130 is disposed on the cryogenic supply pipe 110, which pumps the cryogenic molten salt medium in the cryogenic molten salt tank 100 to the molten salt electric heater 300. The molten salt electric heater 300 is connected to a power system, which supplies power to the molten salt electric heater 300.

[0030] The end of the molten salt electric heater 300 away from the low-temperature supply pipe 110 is connected to a high-temperature reflux pipe 210. A first molten salt valve 230 is installed on the high-temperature reflux pipe 210 to control the opening and closing of the high-temperature reflux pipe 210. The end of the high-temperature reflux pipe 210 away from the molten salt electric heater 300 is connected to a high-temperature molten salt tank 200. A high-temperature supply pipe 220 is connected to the high-temperature molten salt tank 200. The end of the high-temperature supply pipe 220 away from the high-temperature molten salt tank 200 is connected to a steam generator 400. The high-temperature supply pipe 220 is connected to the tube side of the steam generator 400. The end of the tube side of the steam generator 400 away from the high-temperature supply pipe 220 is connected to a low-temperature reflux pipe 120. A second molten salt valve 140 is installed on the low-temperature reflux pipe 120 to control the opening and closing of the low-temperature reflux pipe 120. The low-temperature reflux pipe 120 is connected to the low-temperature molten salt tank 100 to realize the circulation loop of the molten salt medium.

[0031] Reference Figure 1 and Figure 2 A heat exchange mechanism 500 is connected to the steam generator 400. The heat exchange mechanism 500 includes a first water tank 510 containing circulating water. A pump pipe 520 is connected to the first water tank 510, and a water pump 530 is installed on the pump pipe 520. The end of the pump pipe 520 away from the first water tank 510 is connected to the steam generator 400. A steam pipe 550 is connected to the end of the steam generator 400 away from the pump pipe 520. The end of the steam pipe 50 away from the steam generator 400 is connected to a heat exchanger 540. The steam pipe 550 is connected to the tube side inside the heat exchanger 540. The end of the steam pipe 550 away from the steam pipe 550 is connected to a return water pipe 560. A return water valve 570 is installed on the return water pipe 560. The return water valve 570 is used to control the opening and closing of the return water pipe 560, forming a circulating water return. The circulating water exchanges heat with the high-temperature molten salt medium in the steam generator 400.

[0032] Both ends of the heat exchanger 540 are connected to circulation pipes 600. The ends of the two circulation pipes 600 away from the heat exchanger 540 are respectively connected to the inlet and outlet of the user's heat end. A circulation water pump 610 is installed on the circulation pipe 600 connected to the inlet of the user's heat end.

[0033] During periods of low electricity demand, the first molten salt pump 130 is started to pump the low-temperature molten salt medium in the low-temperature molten salt tank 100 to the molten salt electric heater 300. The molten salt electric heater 300 then electrically heats the low-temperature molten salt medium. After the low-temperature molten salt medium is heated to form a high-temperature molten salt medium, it will be pumped into the high-temperature molten salt tank 200 for storage, thus achieving the storage of electrical energy. During peak electricity consumption periods, when heating is required for users, the second molten salt pump 240 extracts the high-temperature molten salt medium stored in the high-temperature molten salt tank 200 and pumps it into the tube side of the steam generator 400. Simultaneously, the water supply pump 530 pumps the circulating water from the first water tank 510 into the steam generator 400. The circulating water exchanges heat with the high-temperature molten salt medium in the steam generator 400 to form steam, which enters the tube side of the heat exchanger 540. After the high-temperature molten salt medium dissipates heat, it flows back to the low-temperature molten salt tank 100 through the low-temperature return pipe 120, waiting to store energy during off-peak electricity consumption periods. At the same time, the hot water supplied for cooling the heating end is also pumped into the heat exchanger 540 by the circulating water pump 610. The steam exchanges heat with the hot water to heat it, and then the steam condenses and flows back to the first water tank 510, waiting to continue the circulation. By utilizing off-peak electricity through energy storage, heating costs are reduced without increasing the burden during peak electricity consumption periods.

[0034] Reference Figure 2 and Figure 3 In the process of storing off-peak electricity using molten salt, energy loss is inevitable. In order to reduce unnecessary energy loss, a second water tank 700 is placed between the high-temperature lava tank and the low-temperature molten salt tank 100. The second water tank 700 is equipped with an electric heating tube connected to the power system. The second water tank 700 contains hot water, and the electric heating tube can directly heat the hot water in the second water tank 700 under the power supply of the power system.

[0035] Each circulation pipe 600 is connected to two branch pipes 620. One branch pipe 620 connected to the same circulation pipe 600 is connected to the heat exchanger 540, and the other branch pipe 620 is connected to the second water tank 700. Each branch pipe 620 is equipped with a first control valve 630, which controls the opening and closing of the branch pipe 620 it is connected to. During peak electricity consumption periods, the circulation pipe 600 is connected to the heat exchanger 540 to provide heat using the energy stored in the high-temperature molten salt medium. During off-peak electricity consumption periods, both circulation pipes 600 are connected to the second water tank 700 through the branch pipes 620 to directly heat the hot water in the second water tank 700 using off-peak electricity. The heated water is then circulated through the circulation pipe 600 to the user's heating end, thus realizing the direct utilization of off-peak electricity and reducing energy loss.

[0036] Reference Figure 2 and Figure 3 The bottom of the second water tank 700 is connected to a drain pipe 710, and an on / off valve 720 is installed on the drain pipe 710. The on / off valve 720 is used to control the opening and closing of the drain pipe 710.

[0037] A first connecting pipe 730 connects the low-temperature molten salt tank 100 and the second water tank 700. A third molten salt pump 731 is installed on the first connecting pipe 730, which pumps the low-temperature molten salt medium in the low-temperature molten salt tank 100 into the second water tank 700. A second connecting pipe 740 connects the high-temperature molten salt tank 200 and the second water tank 700. A fourth molten salt pump 741 is installed on the second connecting pipe 741, which pumps the high-temperature molten salt medium in the high-temperature molten salt tank 200 into the second water tank 700.

[0038] Reference Figure 2 and Figure 3 The ends of the low-temperature supply pipe 110 and the low-temperature return pipe 120 near the low-temperature molten salt tank 100 are both connected to the first three-way valve 150. Both ports of the first three-way valve 150 are connected to the low-temperature diversion pipe 160. Two low-temperature diversion pipes 160 connected to the same first three-way valve 150 are connected, one of which is connected to the low-temperature molten salt tank 100 and the other is connected to the inside of the second water tank 700.

[0039] The ends of the high-temperature supply pipe 220 and the high-temperature return pipe 210 near the high-temperature molten salt tank 200 are both connected to the second three-way valve 250. Both ports of the second three-way valve 250 are connected to the high-temperature diversion pipe 260. Two high-temperature diversion pipes 260 connected to the same second three-way valve 250 are connected, one of which is connected to the high-temperature molten salt tank 200 and the other is connected to the inside of the second water tank 700. With increasing energy storage demand, molten salt tanks are becoming larger, making them susceptible to damage during use. When the low-temperature molten salt tank 100 or the high-temperature molten salt tank 200 requires maintenance, the on / off valve 720 is opened to drain the hot water from the second water tank 700. Then, the third molten salt pump 731 or the fourth molten salt pump 741 is started to pump the molten salt medium from the low-temperature molten salt tank 100 or the high-temperature molten salt tank 200 to the second water tank 700 for storage, facilitating timely transfer of the molten salt medium. Simultaneously, to ensure the continued operation of the heating system, after the low-temperature molten salt tank 100 is damaged and the low-temperature molten salt medium is pumped to the second water tank 700, the first three-way valve 150 and the low-temperature supply pipe 110 are controlled. Both the low-temperature reflux pipe 120 and the low-temperature diversion pipe 160 extending into the second water tank 700 are connected, allowing the low-temperature molten salt medium temporarily stored in the second water tank 700 to be pumped, enabling the molten salt energy storage system to continue operating. When the high-temperature molten salt tank 200 is damaged and the high-temperature molten salt medium is pumped into the second water tank 700, the second three-way valve 250 is controlled, and the high-temperature supply pipe 220 and the high-temperature reflux pipe 210 are both connected to the low-temperature diversion pipe 160 extending into the second water tank 700, allowing the high-temperature molten salt medium temporarily stored in the second water tank 700 to be pumped, thus achieving continuous operation of the molten salt energy storage system, reducing the possibility of molten salt energy storage system shutdown, and ensuring the continuous efficiency of the molten salt energy storage system.

[0040] Reference Figure 3and Figure 4 A partition box 800 is fixedly connected inside the second water tank 700. The partition box 800 is located in one corner inside the second water tank 700. A connecting port is provided on the side wall of the partition box 800. The partition box 800 communicates with the inside of the second water tank 700 through the connecting port. An opening and closing mechanism 810 is installed on the second water tank 700. The opening and closing mechanism 810 is used to close the connecting port on the partition box 800.

[0041] Reference Figure 4 and Figure 5 The opening and closing mechanism 810 includes an electric cylinder 811 fixedly connected to the outside of the second water tank 700. The piston rod of the electric cylinder 811 is fixedly connected to a sealing plate 812. The sealing plate 812 passes through the side wall of the second water tank 700 and is slidably and sealingly connected to the side wall of the second water tank 700. After passing through the second water tank 700, the sealing plate 812 is slidably and sealingly connected to the side wall of the partition box 800. When the sealing plate 812 slides into the interior of the second water tank 700, the sealing plate 812 blocks the communication port on the partition box 800.

[0042] The second connecting pipe 740 extends into the second water tank 700 and then passes through the partition box 800, connecting with the partition box 800. The low temperature distribution pipe 160, which connects to the low temperature supply pipe 110, passes through the partition box 800 and connects with the partition box 800. A temperature sensor is installed on the cryogenic supply pipe 110 to check the temperature of the molten salt medium inside the cryogenic supply pipe 110. The temperature sensor is electrically connected to an external controller. When the second water tank 700 is used to store the cryogenic or high-temperature molten salt medium, the connection port is open to ensure smooth utilization of the molten salt medium. During the operation of the molten salt energy storage system, if the temperature of the cryogenic molten salt medium is too low, its fluidity will deteriorate and it will block the cryogenic pump pipe. The temperature sensor detects the temperature of the molten salt medium inside the cryogenic supply pipe 110. When the temperature of the cryogenic molten salt medium is detected to be too low, the external controller controls the first three-way valve 150 on the cryogenic supply pipe 110 to control the cryogenic supply pipe 110 to alternately connect with the two cryogenic diversion pipes 160. This allows the cryogenic molten salt medium and the high-temperature molten salt medium in the isolation box 800 to be alternately extracted, so that the high-temperature molten salt medium neutralizes the cryogenic molten salt medium, increases the temperature of the cryogenic molten salt medium, and reduces the possibility of the cryogenic molten salt medium blocking the cryogenic supply pipe 110.

[0043] The implementation principle of a molten salt energy storage system according to an embodiment of this application is as follows: During off-peak electricity demand, the first molten salt pump 130 pumps the low-temperature molten salt medium in the low-temperature molten salt tank 100 to the molten salt electric heater 300. The low-temperature molten salt medium is electrically heated using off-peak electricity. After the low-temperature molten salt medium absorbs energy to form a high-temperature molten salt medium, it is pumped to the high-temperature molten salt tank 200 for storage, thereby realizing the storage of electrical energy. During peak electricity consumption periods, the high-temperature molten salt medium in the high-temperature molten salt tank 200 is pumped to the tube side of the steam generator 400. At the same time, the water supply pump 530 sends the circulating water pump 610 to the steam generator 400. The circulating water and the high-temperature molten salt medium exchange heat in the steam generator 400. The circulating water vaporizes to form steam, which then enters the heat exchange mechanism 500. The steam then heats the hot water supplied to the user's heating end to achieve heating. By utilizing off-peak electricity through energy storage, heating costs are reduced without increasing the burden during peak electricity consumption periods.

[0044] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A molten salt energy storage system, characterized in that: include: Low-temperature molten salt vessel (100) is used to hold low-temperature molten salt medium; High-temperature molten salt tank (200) is used to hold high-temperature molten salt media; A molten salt electric heater (300) is connected to an electrical system, which supplies power to the molten salt electric heater (300). Both the low-temperature molten salt tank (100) and the high-temperature molten salt tank (200) are connected to the molten salt electric heater (300). The low-temperature molten salt medium in the low-temperature molten salt tank (100) is pumped into the high-temperature molten salt tank (200) after passing through the molten salt electric heater (300). A steam generator (400) is provided, wherein the high-temperature molten salt tank (200) is connected to the tube side of the steam generator (400), the high-temperature molten salt medium inside the high-temperature molten salt tank (200) flows to the tube side of the steam generator (400), and the end of the tube side of the steam generator (400) away from the high-temperature molten salt tank (200) is connected to the low-temperature molten salt tank (100). A heat exchange mechanism (500) is used to circulate water to a steam generator (400). The steam generated by the heat exchange between the circulating water and the high-temperature molten salt medium in the steam generator (400) will enter the heat exchange mechanism (500). The heat exchange mechanism (500) heats the hot water supplied to the user's heating end with steam. A low-temperature supply pipe (110) is connected between the low-temperature molten salt tank (100) and the molten salt electric heater (300), and a first molten salt pump (130) is installed on the low-temperature supply pipe (110). A high-temperature reflux pipe (210) is connected between the molten salt electric heater (300) and the high-temperature molten salt tank (200). A high-temperature supply pipe (220) is connected between the high-temperature molten salt tank (200) and the tube side of the steam generator (400), and a second molten salt pump (240) is installed on the high-temperature supply pipe (220). A low-temperature reflux pipe (120) is connected between the tube side of the steam generator (400) and the low-temperature molten salt tank (100). The heat exchange mechanism (500) includes a heat exchanger (540) and a first water tank (510). Both ends of the heat exchanger (540) are connected to circulation pipes (600). The two circulation pipes (600) are respectively connected to the inlet and outlet of the user's heating end. The first water tank (510) is connected to the steam generator (400). The end of the steam generator (400) away from the first water tank (510) is connected to the tube side of the heat exchanger (540). The end of the heat exchanger (540) away from the steam generator (400) is connected to the first water tank (510). A second water tank (700) is provided on one side of the first water tank (510). An electric heating tube is provided inside the second water tank (700). The electric heating tube is connected to an electric power system, which supplies power to the electric heating tube. Each circulation pipe (600) is connected to two branch pipes (620). One branch pipe (620) is connected to the heat exchanger (540), and the other branch pipe (620) is connected to the second water tank (700). A first control valve (630) is provided on each branch pipe (620). The low-temperature molten salt tank (100) is connected to the second water tank (700) through a first connecting pipe (730), and the high-temperature molten salt tank (200) is connected to the second water tank (700) through a second connecting pipe (740).

2. The molten salt energy storage system according to claim 1, characterized in that: A third molten salt pump (731) is provided on the first connecting pipe (730), and a fourth molten salt pump (741) is provided on the second connecting pipe (740).

3. The molten salt energy storage system according to claim 2, characterized in that: The low-temperature supply pipe (110) and the low-temperature return pipe (120) are both connected to a first three-way valve (150) at the end near the low-temperature molten salt tank (100). Each of the two ports of the first three-way valve (150) is connected to a low-temperature diversion pipe (160). One of the low-temperature diversion pipes (160) is connected to the low-temperature molten salt tank (100), and the other of the low-temperature diversion pipes (160) is connected to the second water tank (700). The high-temperature return pipe (210) and the high-temperature supply pipe (220) are both connected to a second three-way valve (250) at the end near the high-temperature molten salt tank (200). Each of the two ports of the second three-way valve (250) is connected to a high-temperature diversion pipe (260). One of the high-temperature diversion pipes (260) is connected to the high-temperature molten salt tank (200), and the other of the high-temperature diversion pipes (260) is connected to the low-temperature molten salt tank (100).

4. The molten salt energy storage system according to claim 3, characterized in that: The second water tank (700) is provided with a partition box (800), and the partition box (800) is provided with an opening and closing mechanism (810). The opening and closing mechanism (810) is used to control the opening and closing of the partition box (800). When the opening and closing mechanism (810) drives the partition box (800) to open, the partition box (800) is connected to the interior of the second water tank (700). The second connecting pipe (740) extends into the second water tank (700) and then passes through the partition box (800). The low temperature diversion pipe (160) connected to the low temperature supply pipe (110) extends into the second water tank (700) and then passes through the partition box (800).

5. A molten salt energy storage system according to claim 4, characterized in that: The partition box (800) has a communication port on one side. The opening and closing mechanism (810) includes an electric push cylinder (811) and a sealing plate (812). The sealing plate (812) is installed on the side wall of the second water tank (700). The sealing plate (812) is slidably connected to the second water tank (700). The second water tank (700) is slidably connected to the partition box (800). The sealing plate (812) is used to block the communication port.

6. A molten salt energy storage system according to claim 1, characterized in that: The bottom of the second water tank (700) is connected to a drain pipe (710), and the drain pipe (710) is equipped with an on / off valve (720).

Images