Molten salt energy storage combined heat and power generation system and molten salt energy storage heat exchange device thereof

Abstract

The invention discloses a fused salt energy storage combined heat and power generation system and a fused salt energy storage heat exchange device thereof, and relates to the technical field of high-temperature fused salt heat storage. The fused salt energy storage combined heat and power generation system comprises a low-temperature fused salt tank, a fused salt electric heater, an energy storage heat exchanger, a steam turbine water supply module, a reheater, a high-pressure cylinder, an intermediate-pressure cylinder, a low-pressure cylinder and a condenser, and a low-temperature fused salt pump is arranged between the fused salt electric heater and the low-temperature fused salt tank. The heated high-temperature fused salt enters the energy storage heat exchanger; in the heat release process, the steam turbine water supply module is used for supplying water into the energy storage heat exchanger, so that the water exchanges heat with the high-temperature fused salt, the fused salt energy storage combined heat and power generation system mainly takes a fused salt energy storage technology as a core, comprehensively utilizes valley electricity and abandoned electricity in a heat storage mode, and adopts a structure that a heat exchange and energy storage device is separated from a fused salt electric heater; the heating effect is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of high-temperature molten salt heat storage, and in particular to a molten salt energy storage cogeneration system and a molten salt energy storage heat exchange device. Background Art

[0002] Under the carbon peak and carbon neutrality, the installed capacity of renewable energy such as wind power and photovoltaic power in my country has continued to increase. According to data, as of the end of October 2021, my country's cumulative installed capacity of renewable energy power generation reached 1.002 billion kilowatts, doubling from the end of 2015; accounting for 43.5% of the country's total installed capacity of power generation, an increase of 10.2 percentage points from the end of 2015.

[0003] Accelerating the construction of a new power system that adapts to the development of a high proportion of renewable energy means that the power system will become increasingly low-carbon (renewable energy generation) and decentralized (distributed generation). However, renewable energy generation is random and volatile. According to the "Research on Analysis of Key Factors and Solutions for New Energy Consumption", the maximum daily fluctuation of wind power can reach 80% of the installed capacity, and it exhibits certain anti-peak characteristics; photovoltaic power generation is affected by day and night changes, weather changes, and moving clouds, and is also intermittent and volatile. This means that the balancing process of a system with a high proportion of renewable energy access becomes increasingly complex. In order to ensure the stable, efficient and safe operation of the system, the importance of power auxiliary services is becoming increasingly prominent.

[0004] From the perspective of the structure of power auxiliary service compensation costs, peak load regulation, frequency regulation and standby are currently the main types of power auxiliary service market in my country, accounting for more than 90%. Taking the first half of 2019 as an example, the total amount of peak load compensation costs was 5.009 billion yuan, accounting for 38.44% of the total compensation costs; the total amount of frequency regulation compensation costs was 2.701 billion yuan, accounting for 20.73% of the total compensation costs; the total amount of standby compensation costs was 4.741 billion yuan, accounting for 36.38%; the voltage regulation compensation costs were 551 million yuan, accounting for 4.23%; and other compensation costs were 29 million yuan, accounting for 0.22%.

[0005] Peak-shaving services will gradually be replaced by the spot market. Compared with the auxiliary service varieties in mature foreign markets, a major difference is that foreign power auxiliary service markets do not have peak-shaving varieties, but are achieved through real-time markets or balancing mechanisms in the spot market. The "Notice on Further Improving the Pilot Work of Electricity Spot Market Construction" (Fagaibantigai

[2021] No. 339) issued this year has also clearly required that "the spot electricity market will replace the peak-shaving market during the operation of the spot market." With the continuous deepening of the reform of the power system, after the spot market is built and operated, the electricity price in the spot market will guide the changes in the output of power generation units, thereby replacing peak-shaving.

[0006] Existing systems that use molten salt for energy storage and power generation generally use the molten salt in the high-temperature molten salt tank after heating to be pumped to a heat exchanger for heat exchange with water, and use the generated steam to generate electricity.

[0007] In order to avoid heat loss caused by the process of pumping the molten salt in the high-temperature molten salt tank to the heat exchanger, the water pipeline system can be directly assembled in the high-temperature molten salt tank.

[0008] A similar patent with application number CN201410114259.9 proposes a single-tank electric energy storage device, in which the energy storage stage is as follows: heat storage medium is added to the energy storage tank from the heat transfer medium inlet, electric energy is heated by the electric heater to increase the temperature of the heat storage medium in the energy storage tank, and the electric energy is converted into heat energy and transferred to the heat storage medium, which is stored in the energy storage tank until the entire energy storage tank is filled with high-temperature heat storage medium and the energy storage is completed; the heat transfer medium can be molten salt, water or other heat transfer oil, etc. Energy release stage: low-temperature energy release medium enters the energy storage tank from the energy release medium inlet, exchanges heat with the high-temperature heat storage medium, and the temperature increases. The heated high-temperature energy release medium is discharged from the energy release medium outlet, and the discharged high-temperature energy release medium either directly enters the energy utilization device to be utilized, or passes through the energy utilization heat exchanger, and the energy is utilized by the energy utilization heat exchanger and the energy utilization device. Among them, the energy storage stage and the energy release stage can be carried out simultaneously.

[0009] However, it is generally best to store energy during valley power periods and release energy during peak power periods. If the above-mentioned energy storage and heat exchange device adopts a method of storing and releasing energy simultaneously, it will lead to the use of peak power storage. If it adopts a state of releasing energy alone, as the heat exchange proceeds, its overall temperature will become lower and lower over time. During the peak power consumption period of 6-8 pm, its heat exchange capacity is seriously insufficient, affecting the work done by the high-pressure cylinder, the medium-pressure cylinder and the low-pressure cylinder, resulting in a serious drop in power production and insufficient power supply.

[0010] For places with large power requirements, the required molten salt storage tank is very large, and its storage capacity is even as high as 5,000 tons. The above-mentioned structure of arranging a heating device in the tank body has poor heating effect and is not applicable. Summary of the invention

[0011] In view of the shortcomings of the prior art, the present invention provides a molten salt energy storage cogeneration system and a molten salt energy storage heat exchange device, which solves the problems of poor heating effect caused by assembling a heating device in a storage tank in the prior art and the decrease in power generation capacity as time goes by during the day.

[0012] To achieve the above objectives, on the one hand, the present invention provides a molten salt energy storage cogeneration system, including a low-temperature molten salt tank, a molten salt electric heater, an energy storage heat exchanger, a steam turbine feed water module, a reheater, a high-pressure cylinder, a medium-pressure cylinder, a low-pressure cylinder and a condenser, and a low-temperature molten salt pump is provided between the molten salt electric heater and the low-temperature molten salt tank: Heat storage process: the molten salt electric heater can heat the low-temperature molten salt in the low-temperature molten salt tank, and the heated high-temperature molten salt enters the energy storage heat exchanger; Heat release process: The steam turbine water supply module can supply water to the energy storage heat exchanger, so that the water exchanges heat with the high-temperature molten salt, and generates steam that can enter the high-pressure cylinder and the medium-pressure cylinder to do work. The high-temperature molten salt of the energy storage heat exchanger can partially enter the reheater; the exhaust steam formed by the high-pressure cylinder and the medium-pressure cylinder can exchange heat with the high-temperature molten salt in the reheater, and the exhaust steam is heated and pressurized to enter the low-pressure cylinder to do work. The condenser can condense the high-temperature gas in the low-pressure cylinder, and the generated condensed water enters the steam turbine water supply module.

[0013] Furthermore, the energy storage heat exchanger and the reheater are both provided with a reflux pipe, and the reflux pipe is provided with a spent liquid reflux pump. The reflux pipe can return the low-temperature molten salt after heat exchange in the energy storage heat exchanger to the low-temperature molten salt tank.

[0014] On the other hand, the present invention also provides a molten salt energy storage and heat exchange device, including: a high-temperature molten salt tank, which is used to store high-temperature molten salt; an inner floating plate, which is arranged in the high-temperature molten salt tank along the radial section direction of the high-temperature molten salt tank, and the height of the inner floating plate changes with the liquid level of the high-temperature molten salt; a heat exchange tube group, which is assembled on the side of the inner floating plate close to the high-temperature molten salt and changes its height synchronously with the inner floating plate, and the heat exchange tube group can exchange heat with the high-temperature molten salt near the inner floating plate area; a reflux hose, one end of the reflux hose passes through the inner floating plate and contacts with the liquid surface of the high-temperature molten salt, and the other end of the reflux hose enters the connection of the spent liquid reflux pump through the reflux pipe.

[0015] Furthermore, a heat insulation plate is fixedly provided on one side of the inner floating plate close to the high-temperature molten salt, and the heat exchange tube group is located in the area between the inner floating plate and the heat insulation plate; the heat insulation plate divides the molten salt in the high-temperature molten salt tank into two areas of molten salt, wherein the molten salt in one area is the molten salt in the area where the heat exchange tube group is located, and the molten salt in the other area is the molten salt in the remaining areas of the high-temperature molten salt tank, so as to reduce the heat exchange of the molten salt in the two areas; a plurality of groups of through holes are provided on the heat insulation plate, and a valve plate is provided in the through hole, and the valve plate can rotate in the through hole to control the through hole to be in an open or closed state, and the opening of the heat insulation plate can allow the molten salt in the remaining areas to enter the area where the heat exchange tube group is located.

[0016] Furthermore, a storage cylinder 1 is fixedly provided at one end of the heat exchange tube group, a pipe 1 is fixedly passed through the inner floating plate along the axial direction and is fixedly connected to the storage cylinder 1, a compensating hose 1 is fixedly provided at the end of the pipe 1 away from the storage cylinder 1, a pipe 3 is fixedly provided on the top of the high-temperature molten salt tank and passes through the top layer of the tank, and the pipe 3 is fixedly connected to one end of the compensating hose 1; a storage cylinder 2 is fixedly provided at the other end of the heat exchange tube group, a pipe 2 is fixedly passed through the inner floating plate along the axial direction and is fixedly connected to the storage cylinder 2, a compensating hose 2 is fixedly provided at the end of the pipe 2 away from the storage cylinder 2, a pipe 4 is fixedly provided on the top of the high-temperature molten salt tank and passes through the top layer of the tank, and the pipe 4 is fixedly connected to one end of the compensating hose 2; the pipe 3 is used to allow condensed water to enter and the pipe 4 is used to discharge steam, or the pipe 4 is used to allow condensed water to enter and the pipe 3 is used to discharge steam.

[0017] Furthermore, the molten salt energy storage and heat exchange device also includes a reversing valve arranged on the top of the tank top layer, and the reversing valve includes: a valve housing, a side of the valve housing close to the tank top layer is fixedly provided with a bottom joint 1 and a bottom joint 2 arranged side by side, the lower end of the bottom joint 1 is fixedly connected to the connecting pipe 3, and the lower end of the bottom joint 2 is fixedly connected to the connecting pipe 4; a side of the valve housing away from the high-temperature molten salt tank is fixedly provided with a water inlet head and a steam joint arranged side by side, the water inlet head is vertically opposite to the bottom joint 2, and the steam joint is vertically opposite to the bottom joint 1; a valve core, the valve core is located in the valve housing, and the valve core is provided with three groups of valve holes, the first group of valve holes The holes include a vertical valve hole 1 and a vertical valve hole 2, the vertical valve hole 1 can conduct the steam joint and the bottom joint 1, and the vertical valve hole 2 can conduct the water inlet head and the bottom joint 2; the second group of valve holes includes two emptying valve holes, the two emptying valve holes can conduct the steam channel and disconnect the water flow channel; the third group of valve holes includes an inclined hole 1 and an inclined hole 2, the inclined hole 1 can conduct the steam joint and the bottom joint 2, and the inclined hole 2 can conduct the water inlet head and the bottom joint 1; a driving cylinder, the driving cylinder is located at one end of the valve housing, and the piston rod of the driving cylinder can push and pull the valve core by telescoping, so that the three groups of valve holes can work in sequence.

[0018] Furthermore, the molten salt energy storage and heat exchange device also includes an air bag, which is arranged above the reversing valve and is used to supply water to the water inlet head and dehydrate the steam discharged from the steam joint. The air bag includes: an outer shell, which is arranged above the reversing valve, and the outer shell is provided with side-by-side centrifugal dehydrators; a water supply joint, which is arranged on the side of the outer shell close to the centrifugal dehydrator, and the water supply joint is arranged along the tangential direction of the centrifugal dehydrator, and the water supply joint is connected to a water supply pipe, and the water supply pipe is fixedly connected to the steam turbine water supply module; a steam exhaust port, which is arranged on the top wall of the outer shell and vertically opposite to the centrifugal dehydrator, and the steam exhaust port is connected to a steam exhaust pipe, and the steam exhaust pipe is fixedly connected to the high-pressure cylinder and the medium-pressure cylinder.

[0019] Furthermore, the centrifugal dehydrator includes: an inner cylinder, the lower end of which is provided with an integral lower extension part 2, the lower end of which is fixed to the bottom surface of the outer shell, and the upper end of the inner cylinder is provided with an upper extension part 2; a water receiving wheel, which is rotatably assembled on the outside of the upper extension part 2, and the upper end of the water receiving wheel is provided with an upper extension part 1; a conical wire mesh, which is located in the inner cylinder, and a rotating shaft is fixedly provided in the middle of the conical wire mesh, and the upper end of the rotating shaft is fixedly connected to the upper extension part 1 through spokes; an integral conical part is provided at the lower end of the inner cylinder, and a drainage hole 1 is opened on one side of the inner cylinder; a steam inlet pipe is installed on one side of the lower extension part 2, and the other end of the steam inlet pipe is fixedly connected to the steam joint; a drainage hole 2 is provided on one side of the lower extension part 2; water entering the outer shell through the water supply joint enters the reversing valve through the water inlet head.

[0020] Furthermore, an overflow hole is opened on one side of the shell, and the height of the overflow hole is lower than the height of the drain hole 2; a connecting rod passes through the overflow hole, and a sealing plate 1 is fixedly provided on the side of the connecting rod located inside the shell, and a sealing plate 2 is fixedly provided on the side of the connecting rod located outside the shell; one end of the connecting rod is fixedly connected to the piston rod of the driving cylinder; when the vertical valve hole 1 and the vertical valve hole 2 are working, the sealing plate 1 blocks the overflow hole; when the emptying valve hole is working, the overflow hole is in an open state; when the inclined hole 1 and the inclined hole 2 are working, the sealing plate 2 blocks the overflow hole.

[0021] Furthermore, it also includes temperature sensor 1 and temperature sensor 2, wherein temperature sensor 1 is fixed at one end of the heat exchange tube group close to storage cylinder 1, and temperature sensor 2 is fixed at one end of the heat exchange tube group close to storage cylinder 2, and is used to detect the temperature of the high-temperature molten salt on both sides of the heat exchange tube group area; a controller, the detection results of temperature sensor 1 and temperature sensor 2 are transmitted to the controller, and the controller controls the operation of the spent liquid reflux pump.

[0022] The present invention has the following beneficial effects: 1. The molten salt energy storage cogeneration system mainly takes molten salt energy storage technology as the core. It converts electricity into heat and stores it in molten salt through the comprehensive utilization of valley electricity and abandoned electricity in a heat storage manner. When the application scenario matures, high-temperature and high-pressure steam is produced through heat exchange equipment, and the steam turbine performs work to achieve cogeneration and grid auxiliary services. In addition, it adopts a structure that separates the heat exchange energy storage device from the molten salt electric heater, so that the molten salt flowing through the molten salt electric heater can be heated and then enter the energy storage heat exchange device, so that a small amount of molten salt is in contact with the molten salt electric heater, thus ensuring the heating effect.

[0023] 2. The molten salt energy storage heat exchange device, on the one hand, sets the heat exchange tube group inside the tank body, abandons the molten salt transportation pipeline for transporting the molten salt in the high-temperature molten salt tank to the molten salt in the heat exchanger, saves the cost of setting up long-distance pipelines, and makes the device occupy a small area; on the other hand, because the heat exchange tube group in this embodiment can change with the height change of the inner floating plate, the heat exchange tube group changes the heat exchange area of ​​the high-temperature molten salt, so that the high-temperature molten salt with reduced temperature is discharged immediately, avoiding the situation where the temperature of the molten salt in the low temperature area is transferred to the high-temperature molten salt in the high temperature area, causing the temperature of the molten salt in the entire high-temperature molten salt tank to be synchronously reduced.

[0024] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the molten salt energy storage cogeneration system of the present invention; Figure 2 It is an overall diagram of the molten salt energy storage and heat exchange device of the present invention; Figure 3 This is a schematic diagram of the internal structure of the molten salt energy storage and heat exchange device of the present invention; Figure 4 It is a schematic structural diagram of the heat insulation board of the present invention; Figure 5 It is a structural schematic diagram of the heat insulation board of the present invention without assembling the valve plate; Figure 6 It is a structural schematic diagram of the valve plate of the present invention; Figure 7 It is a pipe system connection diagram of the heat exchange tube group of the present invention; Figure 8 For the present invention Figure 3 Schematic diagram of the unassembled tank top layer; Fig. 9 This is an appearance diagram of the reversing valve of the present invention; Fig.10 It is a schematic diagram of the internal structure of the reversing valve of the present invention; Fig.11 It is a schematic diagram of the second state of the reversing valve of the present invention; Fig.12 It is a schematic diagram of the first emptying state of the reversing valve of the present invention; Fig.13 It is a schematic diagram of the second emptying state of the reversing valve of the present invention; Fig.14 It is a schematic diagram of the reversing valve state 1 of the present invention; Fig.15 It is a schematic diagram of the internal structure of the steam drum of the present invention; Fig.16 It is a structural schematic diagram of the centrifugal dehydrator of the present invention.

[0026] In the figure, 1. low-temperature molten salt tank; 2. molten salt electric heater; 3. energy storage heat exchanger; 4. turbine feed water module; 5. reheater; 6. high-pressure cylinder; 7. medium-pressure cylinder; 8. low-pressure cylinder; 9. condenser; 10. low-temperature molten salt pump; 11. feed water booster pump; 12. spent liquid reflux pump; 310, high-temperature molten salt tank; 310b, tank top layer; 311, pressure relief valve; 312, ladder; 313a, top manhole; 313b, high-position manhole; 313c, low-position manhole; 314, molten salt inlet interface; 315, return hose; 316, light-transmitting hole; 317, tank top vent; 318, drain valve; 320, air bag; 321, outer shell; 321a, overflow hole; 322, steam exhaust port; 322a, steam exhaust pipe; 323, water supply joint; 323a, water supply pipe; 324, centrifugal dehydrator; 3241, water receiving wheel; 3241a, upper extension part 1; 3242, spokes; 3243, rotating shaft; 3244, conical wire mesh; 3245, inner cylinder; 3245a, upper extension part 2; 3245b, conical part; 3245c, drainage hole 1; 3245d, lower extension part 2; 3245e, drainage hole 2; 3246, steam inlet pipe; 330, inner floating plate; 331, sealing ring; 332, buoy; 333, floating plate manhole; 340, heat exchange tube group; 341, storage cylinder 1; 341a, pipe 1; 341b, compensation hose 1; 341c, pipe 3; 342, storage cylinder 2; 342a, pipe 2; 342b, compensation hose 2; 342c, pipe 4; 343, hanging frame; 350, driving cylinder; 360, reversing valve; 361, valve housing; 362, water inlet head; 363, steam joint; 364, bottom joint 1; 365, bottom joint 2; 366, connecting rod; 367, valve core; 367a, vertical valve hole 1; 367b, vertical valve hole 2; 367c, drain valve hole; 367d, inclined hole 1; 367e, inclined hole 2; 370, connecting rod; 370a, sealing plate 1; 370b, sealing plate 2; 380, heat insulation board; 380a, through hole; 380b, through hole; 381, suspension rod; 382, ​​valve plate; 391. Temperature sensor one; 392. Temperature sensor two. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] In the description of the present invention, it should be understood that the terms "opening", "upper", "lower", "thickness", "top", "middle", "length", "inside", "all around" and the like indicating orientation or positional relationship are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the components or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0029] According to the following Figure 1-Figure 16 The present invention describes a molten salt energy storage cogeneration system and a molten salt energy storage heat exchange device provided in an embodiment of the present invention.

[0030] On the one hand, the embodiment of the present invention provides a molten salt energy storage cogeneration system, please refer to Figure 1 .

[0031] The molten salt energy storage cogeneration system comprises a low-temperature molten salt tank 1, a molten salt electric heater 2, an energy storage heat exchanger 3, a steam turbine feed water module 4, a reheater 5, a high-pressure cylinder 6, a medium-pressure cylinder 7, a low-pressure cylinder 8 and a condenser 9. A low-temperature molten salt pump 10 is provided between the molten salt electric heater 2 and the low-temperature molten salt tank 1. A reflux pipe is provided on the energy storage heat exchanger 3 and the reheater 5. A spent liquid reflux pump 12 is provided on the reflux pipe. The reflux pipe is used to return the low-temperature molten salt after heat exchange in the energy storage heat exchanger 3 to the low-temperature molten salt tank 1. It includes a heat storage stage and a heat release stage; ① Heat storage stage: During the period when valley electricity or clean energy such as wind and solar power generates abandoned electricity (cannot be connected to the grid or cannot be absorbed), the low-temperature molten salt pump 10 is started, and the low-temperature molten salt in the low-temperature molten salt tank 1 flows through the molten salt electric heater 2 under the work of the pump. The molten salt electric heater 2 is used to heat the low-temperature molten salt in the low-temperature molten salt tank 1. The low-temperature molten salt is heated from 290°C to 560°C and then stored in the energy storage heat exchanger 3 (high-temperature molten salt tank 310), and the heat storage process is completed.

[0032] The specific flow rate of the low-temperature molten salt pump 10 here is adjusted according to the total amount of molten salt, the heating rate of the molten salt electric heater 2 and the duration of the heat storage process.

[0033] ② Heat release stage: The high-temperature molten salt that has been heated and stored in the heat storage process is stored in the high-temperature molten salt tank 310. After the heat release process begins, a pump is used to pump out part of the high-temperature molten salt into the reheater 5. The steam turbine feed water module 4 provides qualified feed water to enter the energy storage heat exchanger 3 for heat exchange, and produces high-temperature and high-pressure superheated steam, which flows through the high-pressure cylinder 6 and the medium-pressure cylinder 7 respectively, driving the steam turbine to rotate and do work, driving the generator to generate electricity.

[0034] In the reheater 5, the high-temperature molten salt exchanges heat again with the exhaust steam generated by the high-pressure cylinder 6 and the medium-pressure cylinder 7. The exhaust steam is heated and pressurized in the reheater 5 and then goes to the low-pressure cylinder 8 to perform work. The steam in the low-pressure cylinder 8 passes through the condenser 9, which condenses the steam by water cooling and recovers the heat in the steam. The condensed feed water returns to the steam turbine feed water module 4. The steam turbine feed water module 4 contains water treatment, deaerator, high and low pressure boosters. The water treated by the steam turbine feed water module 4 forms heat exchange water that can exchange heat with the energy storage heat exchanger 3. The heat exchange water absorbs the heat recovered by the condenser 9 before entering the energy storage heat exchanger 3, thereby raising the water temperature to 50-60°. The heat exchange water with the increased water temperature is sent to the energy storage heat exchanger 3 by the feed water booster pump 11 for further heat exchange.

[0035] After completing the above heat exchange function, the temperature of the high-temperature molten salt drops from 560°C to 290°C, turning into low-temperature molten salt. Under the action of the spent liquid reflux pump 12, it flows through the system molten salt pipeline to and is stored in the low-temperature molten salt tank 1, preparing for the next heat storage.

[0036] At this point, the heat storage and heat release process of the system of the present invention is completed.

[0037] The parameters of superheated steam produced by heat exchange between molten salt and system feed water are generally determined according to the technical requirements of the steam turbine feed water module 4 for superheated steam. Under normal circumstances, the superheated steam outlet parameter is 540℃ / 14.42MPa; the steam outlet parameter after reheating in the reheater 5 is 540℃ / 2.732MPa.

[0038] The system can not only generate electricity, but also supply high-quality industrial steam to the outside by extracting steam to achieve cogeneration. By calculating and configuring the core equipment parameters such as molten salt heat storage, molten salt electric heater power, and steam turbine system power, the free combination of various results such as system power generation time, external steam supply time, and steam parameters can be achieved to adapt to different application scenarios.

[0039] Preferably, the molten salt in the present invention is a binary salt.

[0040] The above processes are all completed under the control of the intelligent control system. According to the temperature, flow, pressure and other intelligent terminal hardware data feedback installed in the system, the intelligent control system calculates the output to realize automatic operation of the system.

[0041] On the other hand, the present invention also provides a molten salt energy storage heat exchange device, see Figure 2-Figure 16 .

[0042] Combination Figure 2 and Figure 3 The molten salt energy storage heat exchange device is actually the above-mentioned energy storage heat exchanger 3, which includes a high-temperature molten salt tank 310, which is used to store high-temperature molten salt. An inner floating plate 330 is provided in the high-temperature molten salt tank 310 along its own radial section direction. The inner floating plate 330 can float on the liquid surface of the high-temperature molten salt due to the buoyancy of the high-temperature molten salt, that is, the height of the inner floating plate 330 is the same as the liquid level of the high-temperature molten salt, and changes with the change of the liquid level of the high-temperature molten salt. A heat exchange tube group 340 is assembled on the side of the inner floating plate 330 close to the high-temperature molten salt. The heat exchange tube group 340 can change its height synchronously with the inner floating plate 330, so that the position of the heat exchange tube group 340 can also change. Since the height of the heat exchange tube group 340 is always located close to the liquid surface, the heat exchange tube group 340 can exchange heat with the high-temperature molten salt in the area close to the inner floating plate 330, so that the water in the heat exchange tube group 340 can form high-temperature and high-pressure steam required by the steam turbine.

[0043] Therefore, the molten salt energy storage heat exchange device provided in the embodiment of the present invention, on the one hand, directly sets the heat exchange tube group 340 inside the tank body loaded with high-temperature molten salt, abandons the molten salt transportation pipeline for transporting the molten salt in the high-temperature molten salt tank 310 to the molten salt in the heat exchanger, saves the cost of setting long-distance pipelines, and makes the device occupy a small area; on the other hand, since the heat exchange tube group 340 in this embodiment can change with the height change of the inner floating plate 330, the heat exchange tube group 340 changes the heat exchange area of ​​the high-temperature molten salt, so that the high-temperature molten salt with reduced temperature is discharged immediately, avoiding the molten salt temperature in the low-temperature area from being transferred to the high-temperature molten salt in the high-temperature area, which causes the temperature of the molten salt in the entire high-temperature molten salt tank 310 to decrease synchronously (the temperature in the entire high-temperature molten salt tank 310 decreases synchronously within a unit time, which will make its overall temperature lower and lower with the passage of time. At the peak of electricity consumption from 6 to 8 pm, its heat exchange capacity is seriously insufficient, affecting the work of the high-pressure cylinder 6, the medium-pressure cylinder 7 and the low-pressure cylinder 8, resulting in a serious decrease in power production and insufficient power supply).

[0044] In addition, the inner floating plate 330 here can also reduce the volatilization amount of high-temperature molten salt and the heat loss.

[0045] Preferably, a guide rod for guiding the inner floating plate 330 is further provided in the high-temperature molten salt tank 310 .

[0046] Preferably, the heat exchange tube group 340 is fixed below the inner floating plate 330 by a hanging frame 343 .

[0047] Preferably, the inner floating plate 330 is made of stainless steel, and a buoy 332 is assembled thereunder so that the inner floating plate 330 has the ability to float.

[0048] Preferably, a metal sealing ring 331 is provided at the edge of the inner floating plate 330 .

[0049] Preferably, at least two groups of floating plate manholes 333 are provided on the upper surface of the inner floating plate 330 . The nominal diameter of the floating plate manholes 333 is generally 500 mm. A sealing plate is locked on the floating plate manholes 333 by bolts.

[0050] Furthermore, since the high-temperature molten salt in the area of ​​the heat exchange tube group 340 will gradually become low-temperature molten salt after heat exchange, a reflux hose 315 is also provided here. One end of the reflux hose 315 passes through the inner floating plate 330 and contacts the liquid surface of the high-temperature molten salt, and the other end of the reflux hose 315 enters the connection of the spent liquid reflux pump 12 through the reflux pipe. When the high-temperature molten salt in the area of ​​the heat exchange tube group 340 becomes low-temperature molten salt, the spent liquid reflux pump 12 works and can transport the molten salt with lower temperature back to the low-temperature molten salt tank 1 through the reflux hose 315.

[0051] The high-temperature molten salt tank 310 is also provided with the same pipe as the return hose 315 , and is connected to the reheater 5 .

[0052] like Figure 3-Figure 6 As shown, preferably, in order to further avoid the fusion of the molten salt whose temperature is gradually reduced in the area of ​​the heat exchange tube group 340 and the molten salt temperature in the lower area that has not yet undergone heat exchange, a heat insulation plate 380 is fixedly provided on the side of the inner floating plate 330 close to the high-temperature molten salt, and the heat exchange tube group 340 is located in the area between the inner floating plate 330 and the heat insulation plate 380. The heat insulation plate 380 divides the molten salt in the high-temperature molten salt tank 310 into two areas of molten salt, wherein the molten salt in one area is the molten salt in the area where the heat exchange tube group 340 is located, and the molten salt in the other area is the molten salt in the remaining areas of the high-temperature molten salt tank 310, so as to reduce the heat exchange of the molten salt in the two areas, thereby ensuring the high temperature state of the molten salt below the heat insulation plate 380, so that even during the peak electricity consumption from 6 to 8 pm, the heat exchange capacity is still strong, providing better power supply capacity.

[0053] Preferably, a through hole 380 b is provided on the heat insulation plate 380 for the guide rod to pass through.

[0054] Preferably, the heat insulation board 380 is a component of a composite polyurethane foam board in a stainless steel sleeve, and is fixed below the inner floating plate 330 through a suspension rod 381.

[0055] In fact, the molten salt drawn out by the return hose 315 is the molten salt in the area around the heat exchange tube group 340. As the return hose 315 is drawn out, the liquid level of the high-temperature molten salt drops, and the insulation board 380 and the inner floating plate 330 both move downward. During this process, the high-temperature molten salt under the insulation board 380 needs to re-enter the area where the heat exchange tube group 340 is located (i.e., the area between the insulation board 380 and the inner floating plate 330). The insulation board 380 is provided with a plurality of through holes 380a. A valve plate 382 is provided in the hole 380a. When the insulation plate 380 and the inner floating plate 330 move downward synchronously, the valve plate 382 is squeezed by the high-temperature molten salt below and rotates in the through hole 380a, so that the through hole 380a is in an open state. The insulation plate 380 is opened to allow the molten salt in the remaining area to enter the area where the heat exchange tube group 340 is located. Of course, when the insulation plate 380 is stationary, the valve plate 382 is in a horizontal state, which closes the through hole 380a to isolate the upper and lower heat.

[0056] Therefore, the molten salt energy storage and heat exchange device provided in the embodiment of the present invention can further reduce the molten salt temperature exchange between the two areas, thereby reducing the heat loss of the molten salt below, thereby avoiding a significant decrease in power generation capacity in the afternoon and evening.

[0057] Combination Figure 2 , Figure 3 and Figure 7 As shown, in order to realize the water inlet and steam outlet of the heat exchange tube group 340, a storage cylinder 341 is fixedly provided at one end of the heat exchange tube group 340, a connecting pipe 341a which is fixedly penetrated along the axial direction on the inner floating plate 330 and is fixedly connected with the storage cylinder 341, a compensating hose 341b is fixedly provided at one end of the connecting pipe 341a away from the storage cylinder 341, and a connecting pipe 341c which penetrates the top layer 310b of the tank is fixedly provided on the top of the high-temperature molten salt tank 310, and the connecting pipe 341c is fixedly connected to one end of the compensating hose 341b, that is, the connecting pipe 341c, the compensating hose 341b, the connecting pipe 341a, the storage cylinder 341 and the heat exchange tube group 340 form a connected pipeline.

[0058] A second storage cylinder 342 is fixedly provided at the other end of the heat exchange tube group 340, and a second pipe 342a is fixedly passed through the inner floating plate 330 along the axial direction and is fixedly connected to the second storage cylinder 342. A second compensation hose 342b is fixedly provided at one end of the second pipe 342a away from the second storage cylinder 342. A fourth pipe 342c passing through the top layer 310b of the tank is fixedly provided at the top of the high-temperature molten salt tank 310. The fourth pipe 342c is fixedly connected to one end of the second compensation hose 342b, that is, the fourth pipe 342c, the second compensation hose 342b, the second pipe 342a, the second storage cylinder 342 and the heat exchange tube group 340 form a connected pipeline.

[0059] The two connected pipes mentioned above have two usage modes: State 1: pipe 3 341c is used to take in condensed water, and pipe 4 342c is used to discharge steam; State 2: pipe 4 342c is used to take in condensed water, and pipe 3 341c is used to discharge steam; the reason for designing this method of feeding and discharging is that, for example, in the initial state, it is state 2, pipe 4 342c takes in water to be exchanged, and the water flows through compensation hose 2 342b, pipe 2 342a, and storage cylinder 2 342 and then enters heat exchange tube group 340, and the water exchanges heat with high-temperature molten salt in the heat exchange tube group 340. In this heat exchange process, Figure 3 and Figure 7 From the perspective of , for the high-temperature molten salt in the area of ​​the heat exchange tube group 340, the left area first exchanges heat with the cold water. As the water flows gradually to the right, it absorbs less heat, resulting in the molten salt temperature in the area on the right decreasing at a higher rate than the molten salt temperature in the left area. That is, under continuous heat exchange, the heat exchange capacity on the left side is gradually weakened, and the water starts to be exchanged only when it flows to the right side. The heat exchange time is greatly shortened, which may very likely cause the water to be discharged before it forms steam. Therefore, in order to ensure the heat exchange capacity of the high-temperature molten salt in the area of ​​the heat exchange tube group 340, it is switched to state 1 at this time, so that cold water enters the heat exchange tube group 340 from the right, so that the high-temperature molten salt with a higher temperature on the right side can first exchange heat with the cold water to ensure the heat exchange effect.

[0060] In addition, it is worth noting that when water passes through the above-mentioned compensation hose 2 342b or compensation hose 1 341b, it can be preheated due to the influence of the temperature in the high-temperature molten salt tank 310, otherwise the steam in the compensation hose 2 342b or compensation hose 1 341b will not cool down.

[0061] In order to realize the switching between the above-mentioned state 1 and state 2, the molten salt energy storage heat exchange device provided in the embodiment of the present invention further includes a reversing valve 360 ​​disposed at the top of the tank top layer 310b, referring to Figure 3 , Figure 7-Figure 11 shown.

[0062] The reversing valve 360 ​​includes a valve housing 361, and a side of the valve housing 361 close to the tank top layer 310b is fixedly provided with a bottom joint 1 364 and a bottom joint 2 365 arranged side by side. The lower end of the bottom joint 1 364 is fixedly connected to the pipe 3 341c, and the lower end of the bottom joint 2 365 is fixedly connected to the pipe 4 342c, that is, the bottom joint 1 364 forms a passage with the pipe system below the pipe 3 341c, and the bottom joint 2 365 forms a passage with the pipe system below the pipe 4 342c; a side of the valve housing 361 away from the high-temperature molten salt tank 310 is fixedly provided with a water inlet head 362 and a steam joint 363 arranged side by side, the water inlet head 362 is vertically opposite to the bottom joint 2 365, and the steam joint 363 is vertically opposite to the bottom joint 1 364, and a valve core 367 is located in the valve housing 361, and three groups of valve holes are provided on the valve core 367, and the three groups of valve holes are respectively used to form state 1, state 2 and emptying state.

[0063] ① The first group of valve holes is used to form state 2: the valve holes include vertical valve hole 1 367a and vertical valve hole 2 367b. The vertical valve hole 1 367a is used to conduct the steam joint 363 and the bottom joint 1 364, and the vertical valve hole 2 367b is used to conduct the water inlet head 362 and the bottom joint 2 365. At this time, the state is formed. Fig.11 The state shown is Figure 7 From the perspective shown, the heat exchange tube group 340 should have water inlet on the left side and steam exhaust on the right side.

[0064] ② The second group of valve holes is used to form an emptying state. The reason why the emptying state is needed is that, for example, when the state 2 is changed to the state 1, the water inlet on the left side is adjusted to the water inlet on the right side. If the water in the left compensation hose 2 342b is not emptied downward, the water entering from the right side will directly push the water on the left side that has not yet become steam to the pipe 4 342c, which will affect the subsequent steam discharge from the pipe 4 342c. Conversely, when the state 1 is changed to the state 2, this problem will also occur. The valve hole includes an emptying valve hole 367c, and the emptying valve hole 367c has two, one of which is an emptying valve hole 367c in a vertical state, which is used to connect the steam joint 363 and the bottom joint 1 364 (such as Fig.12 ), this state is used to drain the water in the left compensation hose 2 342b downward when the state 2 is changed to the state 1; the other is the inclined state, which is used to connect the steam joint 363 and the bottom joint 2 365 (such as Fig.13 ), this state is used to drain the water in the right compensation hose 341b downward when changing from state one to state two; both states maintain the normal discharge of steam.

[0065] ③ The second group of valve holes is used to form state 1: the valve holes include inclined hole 1 367d, which is used to conduct the steam joint 363 and the bottom joint 2 365, and the inclined hole 2 367e is used to conduct the water inlet head 362 and the bottom joint 1 364. Fig.13 The state shown is Figure 7 From the perspective of FIG. 3 , the heat exchange tube group 340 should have water inlet on the right side and steam exhaust on the left side.

[0066] In addition, a drive cylinder 350 should also be provided, and the drive cylinder 350 is located at one end of the valve housing 361. The piston rod of the drive cylinder 350 is retracted to push and pull the valve core 367, so that the three groups of valve holes can work in sequence.

[0067] It should be noted that, in actual work, the emptying state needs to be maintained for 30-40 seconds, and after 30-40 seconds, the drive cylinder 350 can be activated to adjust to state one or state two.

[0068] Combination Fig.15 and Fig.16As shown, in order to remove moisture from the steam discharged from the steam joint 363, an air bag 320 is also provided here. The air bag 320 is arranged above the reversing valve 360, and in addition to being used to remove moisture from the steam, the air bag 320 is also used to supply water to the water inlet head 362.

[0069] It includes an outer shell 321, a water supply connector 323 and a steam exhaust port 322. The outer shell 321 is arranged above the reversing valve 360. The outer shell 321 is provided with a side-by-side centrifugal dehydrator 324. The water supply connector 323 is arranged on one side of the outer shell 321 close to the centrifugal dehydrator 324, and the water supply connector 323 is arranged along the tangent direction of the centrifugal dehydrator 324. The water supply connector 323 is connected to a water supply pipe 323a, and the water supply pipe 323a is fixedly connected to the steam turbine water supply module 4, so that the cold water provided by the steam turbine water supply module 4 can be rushed to the centrifugal dehydrator 324 through the water supply connector 323, so that the centrifugal dehydrator 324 can dehydrate the steam.

[0070] Preferably, the steam exhaust port 322 is arranged on the top wall of the shell 321 and is vertically opposite to the centrifugal dehydrator 324. The steam exhaust port 322 is connected to a steam exhaust pipe 322a, and the steam exhaust pipe 322a is fixedly connected to the high-pressure cylinder 6 and the medium-pressure cylinder 7.

[0071] Preferably, the centrifugal dehydrator 324 mentioned above includes an inner cylinder 3245 , a water receiving wheel 3241 and a conical wire mesh 3244 .

[0072] The lower end of the inner cylinder 3245 is provided with an integral lower extension part 2 3245d, the lower end of the lower extension part 2 3245d is fixed to the bottom surface of the outer shell 321, the upper end of the inner cylinder 3245 is provided with an upper extension part 2 3245a, a steam inlet pipe 3246 is installed on one side of the lower extension part 2 3245d, the other end of the steam inlet pipe 3246 is fixedly connected to the steam joint 363, the water receiving wheel 3241 is rotatably assembled on the outside of the upper extension part 2 3245a, the upper end of the water receiving wheel 3241 is provided with an upper extension part 1 3241a, and the conical wire mesh 3244 is located in the inner cylinder 3245. A rotating shaft 3243 is fixedly provided in the middle of the conical wire mesh 3244, and the upper end of the rotating shaft 3243 is fixedly connected to the upper extension portion 3241a through the spokes 3242; in this embodiment, when the water supply joint 323 rushes toward the water receiving wheel 3241, the water receiving wheel 3241 drives the conical wire mesh 3244 to rotate through the upper extension portion 3241a and the spokes 3242, and the water in the steam entering from the steam inlet pipe 3246 can be intercepted by the conical wire mesh 3244, and the water attached to the conical wire mesh 3244 is separated from the conical wire mesh 3244 outward by the action of centrifugal force.

[0073] Therefore, the air bag 320 in the molten salt energy storage and heat exchange device provided by the present invention can quickly remove moisture from the steam. In addition, since the steam path is located inside the inner cylinder 3245 and the cold water path is located outside the inner cylinder 3245, the water path and the steam path are completely separated. Compared with the water and gas separation method in the prior art, it can avoid the situation where the water content in the steam increases due to the water in the water path entering the steam.

[0074] Preferably, an integrated conical portion 3245b is provided at the lower end of the inner cylinder 3245, and a drainage hole 3245c is opened on one side of the inner cylinder 3245, so that the water that is separated from the conical screen 3244 by the centrifugal force can be discharged through the drainage hole 3245c.

[0075] Preferably, a second drainage hole 3245e is provided on one side of the second lower extension portion 3245d, so that a small amount of water falling from above the inner cylinder 3245 can be discharged into the outer shell 321 through the second drainage hole 3245e.

[0076] In addition, it is worth mentioning that the water entering the housing 321 through the water supply connector 323 enters the reversing valve 360 ​​through the water inlet head 362 .

[0077] Combination Figure 10-Figure 14 As shown, since steam is still being discharged when the second set of valve holes forms an empty state for the pipe system, the conical wire mesh 3244 still needs to be continuously rotated, so that the water supply pipe 323a also needs to be continuously supplied with water at this time. However, too much water will cause water to flow into the inner tube 3245 through the drainage hole 1 3245c and the drainage hole 2 3245e, resulting in the mixing of the steam path and the water path. Therefore, an overflow hole 321a is opened on one side of the outer shell 321. The height of the overflow hole 321a is lower than the height of the drainage hole 2 3245e. The water discharged from the overflow hole 321a can be sent back to the steam turbine water supply module 4.

[0078] In the non-draining state, the overflow hole 321a does not need to be opened (this is because the water inlet parameter setting, the water level in the outer shell 321 will not exceed the height of the drain hole 2 3245e), so a connecting rod 370 passes through the overflow hole 321a, and a sealing plate 1 370a is fixedly provided on the side of the connecting rod 370 located inside the outer shell 321, and a sealing plate 2 370b is fixedly provided on the side of the connecting rod 370 located outside the outer shell 321, and one end of the connecting rod 370 is fixedly connected to the piston rod of the drive cylinder 350 through a connecting rod 366.

[0079] In the present embodiment, when the vertical valve hole 1 367a and the vertical valve hole 2 367b are working, the sealing plate 1 370a blocks the overflow hole 321a; when the emptying valve hole 367c is working, the overflow hole 321a is in an open state; when the inclined hole 1 367d and the inclined hole 2 367e are working, the sealing plate 2 370b blocks the overflow hole 321a, thereby achieving the purpose of automatically opening the overflow hole 321a in the above-mentioned emptying state.

[0080] Preferably, a sealing gasket is provided on one side of the sealing plate 2 370b and the sealing plate 1 370a close to the overflow hole 321a.

[0081] The molten salt energy storage and heat exchange device provided in an embodiment of the present invention also includes a temperature sensor 1 391, a temperature sensor 2 392 and a controller. The temperature sensor 1 391 is fixed to one end of the heat exchange tube group 340 close to the storage cylinder 1 341, and the temperature sensor 2 392 is fixed to one end of the heat exchange tube group 340 close to the storage cylinder 2 342, and is used to detect the temperature of the high-temperature molten salt on both sides of the heat exchange tube group 340 area.

[0082] In this embodiment, when the detection results of temperature sensor 1 391 and temperature sensor 2 392 meet the set threshold (300° C.), the controller controls the spent liquid reflux pump 12 to operate, thereby extracting a certain amount of lower temperature molten salt from the high temperature molten salt tank 310 .

[0083] Temperature sensor 1 391 and temperature sensor 2 392 have another function, that is, when the temperature difference between the two is greater than 60°C, the control drive cylinder 350 is operated to make the reversing valve 360 ​​work, thereby adjusting the water inlet end of the heat exchange tube group 340 to the exhaust end and the exhaust end to the water inlet end.

[0084] It is worth noting that the hoses used in the present invention are all stainless steel hoses.

[0085] Preferably, a molten salt liquid inlet interface 314 is provided on the lower side of the high-temperature molten salt tank 310, and the molten salt liquid inlet interface 314 is fixed to the pipeline of the molten salt electric heater 2, and a low manhole 313c and a drain valve 318 are also provided at the lower position.

[0086] Preferably, a top manhole 313a, a tank top vent 317, and a light-transmitting hole 316 are also provided on the tank top layer 310b.

[0087] Preferably, a high-position manhole 313 b and a pressure relief valve 311 are provided at a high position of the high-temperature molten salt tank 310 .

[0088] Preferably, a ladder 312 is provided on the periphery of the high-temperature molten salt tank 310 .

[0089] When in use (working), in the initial state, the reversing valve 360 ​​is in state 2, the steam turbine water supply module 4 supplies water through the water supply pipe 323a, the water flows into the shell 321, and the water receiving wheel 3241 rotates, and the water entering the shell 321 passes through the water inlet head 362 and enters the vertical valve hole 2 367b, and then enters the pipe 4 342c through the bottom joint 2 365, and then passes through the compensation hose 2 342b, the pipe 2 342a and the storage cylinder 2 342 in turn to enter the heat exchange tube group 340, the heat exchange tube group The water in 340 first quickly exchanges heat with the high-temperature molten salt on the left, and the steam formed subsequently passes through the storage cylinder 1 341, the pipe 1 341a, the compensation hose 1 341b, the pipe 3 341c, the bottom joint 1 364, the vertical valve hole 1 367a, the steam joint 363 and the steam inlet pipe 3246 to enter the inner cylinder 3245, and is dehydrated by the conical wire mesh 3244. The dehydrated steam enters the high-pressure cylinder 6 and the medium-pressure cylinder 7 through the steam exhaust port 322 and the steam exhaust pipe 322a to perform work. As the heat exchange tube group 340 continues to input cold water, the temperature of the high-temperature molten salt around the heat exchange tube group 340 gradually decreases, especially the high-temperature molten salt on the left, until the detection temperature of the temperature sensor 2 392 is greater than the detection temperature of the temperature sensor 1 391 by 60°C, and the drive cylinder 350 is controlled to work. At this time, Fig.11 In the state shown, the valve core 367 moves to the left, forming Fig.12 In the state shown in FIG. 1 , the water in the left compensation hose 2 342b is drained downward (the draining time is preferably 30-40 seconds), and then the drive cylinder 350 continues to work, and the valve core 367 continues to move to the right until a Fig.14 In the state shown, the water inlet end and the steam exhaust end of the heat exchange tube group 340 are exchanged (state 1 is formed at this time).

[0090] In state one, after the heat exchange tube group 340 has been exchanging heat for a period of time, when the detection values ​​of temperature sensor 1 391 and temperature sensor 2 392 both reach 300°C, the controller controls the spent liquid reflux pump 12 to operate and transport the molten salt with reduced temperature back to the internal storage of the low-temperature molten salt tank 1.

[0091] As the liquid level in the high-temperature molten salt tank 310 drops, the inner floating plate 330 and the heat insulation plate 380 move downward synchronously. The valve plate 382 is squeezed by the high-temperature molten salt below and rotates in the through hole 380a, so that the through hole 380a is in an open state. The insulation plate 380 is opened to allow the molten salt in the remaining area to enter the area where the heat exchange tube group 340 is located. At this time, the heat exchange tube group 340 can exchange heat with the higher temperature molten salt again.

[0092] As the heat exchange proceeds, the temperature of the molten salt on the right side is lower than that of the molten salt on the left side, and the drive cylinder 350 extends, causing the reversing valve 360 ​​to move from Fig.14 The state reaches Fig.13In the state shown, the water in the right compensation hose 341b is emptied downward, and then the valve core 367 continues to move to re-form Fig.11 The state shown (state 2).

Claims

1. Molten salt energy storage cogeneration system, characterized in that: It comprises a low-temperature molten salt tank (1), a molten salt electric heater (2), an energy storage heat exchanger (3), a turbine feedwater module (4), a reheater (5), a high-pressure cylinder (6), a medium-pressure cylinder (7), a low-pressure cylinder (8) and a condenser (9), wherein a low-temperature molten salt pump (10) is provided between the molten salt electric heater (2) and the low-temperature molten salt tank (1); The molten salt electric heater (2) is capable of heating the low-temperature molten salt in the low-temperature molten salt tank (1), and the heated high-temperature molten salt enters the energy storage heat exchanger (3); The steam turbine water supply module (4) can supply water to the energy storage heat exchanger (3), so that the water exchanges heat with the high-temperature molten salt and generates steam that can enter the high-pressure cylinder (6) and the medium-pressure cylinder (7) to perform work. The high-temperature molten salt in the energy storage heat exchanger (3) can partially enter the reheater (5); the exhaust steam formed by the high-pressure cylinder (6) and the medium-pressure cylinder (7) can exchange heat with the high-temperature molten salt in the reheater (5), and the exhaust steam is heated and pressurized to enter the low-pressure cylinder (8) to perform work. The condenser (9) can condense the high-temperature gas in the low-pressure cylinder (8), and the generated condensed water enters the steam turbine water supply module (4).

2. The molten salt energy storage cogeneration system according to claim 2 is characterized in that: The energy storage heat exchanger (3) and the reheater (5) are both provided with a reflux pipe, and the reflux pipe is provided with a spent liquid reflux pump (12). The reflux pipe can return the low-temperature molten salt after heat exchange in the energy storage heat exchanger (3) to the low-temperature molten salt tank (1).

3. The molten salt energy storage heat exchange device used in the molten salt energy storage cogeneration system according to claim 2, characterized in that: include: A high-temperature molten salt tank (310), wherein high-temperature molten salt is stored in the high-temperature molten salt tank (310); An inner floating plate (330), wherein the inner floating plate (330) is arranged in the high-temperature molten salt tank (310) along a radial section direction of the high-temperature molten salt tank (310), and the height of the inner floating plate (330) changes with the liquid level of the high-temperature molten salt; A heat exchange tube group (340), wherein the heat exchange tube group (340) is assembled on a side of the inner floating plate (330) close to the high-temperature molten salt and changes height synchronously with the inner floating plate (330). The heat exchange tube group (340) can exchange heat with the high-temperature molten salt in a region close to the inner floating plate (330); A return hose (315), one end of which passes through the inner floating plate (330) and contacts the liquid surface of the high-temperature molten salt, and the other end of the return hose (315) passes through the return pipe and enters the connection with the spent liquid return pump (12).

4. The molten salt energy storage and heat exchange device according to claim 3 is characterized in that: A heat insulation plate (380) is fixedly provided on one side of the inner floating plate (330) close to the high-temperature molten salt, and the heat exchange tube group (340) is located in the area between the inner floating plate (330) and the heat insulation plate (380); The heat insulation plate (380) divides the molten salt in the high-temperature molten salt tank (310) into two areas of molten salt, wherein the molten salt in one area is the molten salt in the area where the heat exchange tube group (340) is located, and the molten salt in the other area is the molten salt in the remaining areas of the high-temperature molten salt tank (310); The heat insulation plate (380) is provided with a plurality of through holes (380a), and a valve plate (382) is provided in the through hole (380a). The valve plate (382) can rotate in the through hole (380a) to control the through hole (380a) to be in an open or closed state. When the heat insulation plate (380) is opened, molten salt in other areas can enter the area where the heat exchange tube group (340) is located.

5. The molten salt energy storage and heat exchange device according to claim 4 is characterized in that: A storage cylinder 1 (341) is fixedly provided at one end of the heat exchange tube group (340); a pipe 1 (341a) is fixedly passed through the inner floating plate (330) in the axial direction and is in fixed communication with the storage cylinder 1 (341); a compensating hose 1 (341b) is fixedly provided at one end of the pipe 1 (341a) away from the storage cylinder 1 (341); a pipe 3 (341c) is fixedly provided on the top of the high-temperature molten salt tank (310) and passes through the top layer (310b) of the tank; and the pipe 3 (341c) is fixedly connected to one end of the compensating hose 1 (341b); A second storage cylinder (342) is fixedly provided at the other end of the heat exchange tube group (340); a second pipe (342a) is fixedly passed through the inner floating plate (330) along the axial direction and is fixedly connected to the second storage cylinder (342); a second compensation hose (342b) is fixedly provided at one end of the second pipe (342a) away from the second storage cylinder (342); a fourth pipe (342c) is fixedly provided on the top of the high-temperature molten salt tank (310) and passes through the top layer (310b) of the tank; and the fourth pipe (342c) is fixedly connected to one end of the second compensation hose (342b).

6. The molten salt energy storage and heat exchange device according to claim 5, characterized in that: The tank further comprises a reversing valve (360) disposed on the top of the tank top layer (310b), wherein the reversing valve (360) comprises: A valve housing (361), wherein a side of the valve housing (361) close to the tank top layer (310b) is fixedly provided with a bottom joint 1 (364) and a bottom joint 2 (365) arranged side by side, wherein the lower end of the bottom joint 1 (364) is fixedly connected to the pipe 3 (341c), and the lower end of the bottom joint 2 (365) is fixedly connected to the pipe 4 (342c); a side of the valve housing (361) away from the high-temperature molten salt tank (310) is fixedly provided with a water inlet head (362) and a steam joint (363) arranged side by side, wherein the water inlet head (362) is vertically opposite to the bottom joint 2 (365), and the steam joint (363) is vertically opposite to the bottom joint 1 (364); A valve core (367), the valve core (367) being located in the valve housing (361), the valve core (367) being provided with three groups of valve holes, the first group of valve holes comprising a vertical valve hole 1 (367a) and a vertical valve hole 2 (367b), the vertical valve hole 1 (367a) being able to conduct the steam joint (363) and the bottom joint 1 (364), the vertical valve hole 2 (367b) being able to conduct the water inlet head (362) and the bottom joint 2 (365) The second group of valve holes includes two drain valve holes (367c), and the two drain valve holes (367c) can conduct the steam channel and disconnect the water channel; the third group of valve holes includes an inclined hole 1 (367d) and an inclined hole 2 (367e), and the inclined hole 1 (367d) can conduct the steam joint (363) and the bottom joint 2 (365), and the inclined hole 2 (367e) can conduct the water inlet head (362) and the bottom joint 1 (364); A drive cylinder (350) is located at one end of the valve housing (361), and a piston rod of the drive cylinder (350) can push and pull the valve core (367) by extending and retracting.

7. The molten salt energy storage and heat exchange device according to claim 6, characterized in that: It also includes an air bag (320), wherein the air bag (320) is arranged above the reversing valve (360), and the air bag (320) includes: A housing (321), the housing (321) being arranged above the reversing valve (360), and having centrifugal dehydrators (324) arranged side by side in the housing (321); A water supply joint (323), the water supply joint (323) being arranged on a side of the housing (321) close to the centrifugal dehydrator (324), and the water supply joint (323) being arranged along a tangent direction of the centrifugal dehydrator (324), the water supply joint (323) being connected to a water supply pipe (323a), and the water supply pipe (323a) being fixedly connected to a steam turbine water supply module (4); A steam exhaust port (322), the steam exhaust port (322) being arranged on the top wall of the outer shell (321) and vertically opposite to the centrifugal dehydrator (324), the steam exhaust port (322) being connected to a steam exhaust pipe (322a), the steam exhaust pipe (322a) being fixedly connected to the high-pressure cylinder (6) and the medium-pressure cylinder (7).

8. The molten salt energy storage and heat exchange device according to claim 7, characterized in that: The centrifugal dehydrator (324) comprises: An inner cylinder (3245), wherein the lower end of the inner cylinder (3245) is provided with an integral lower extension portion (3245d), the lower end of the lower extension portion (3245d) is fixed to the bottom surface of the outer shell (321), and the upper end of the inner cylinder (3245) is provided with an upper extension portion (3245a); A water receiving wheel (3241), wherein the water receiving wheel (3241) is rotatably assembled outside the second upper extension part (3245a), and the upper end of the water receiving wheel (3241) is provided with the first upper extension part (3241a); A conical wire mesh (3244), the conical wire mesh (3244) being located in the inner cylinder (3245), a rotating shaft (3243) being fixedly arranged in the middle of the conical wire mesh (3244), and an upper end of the rotating shaft (3243) being fixedly connected to an upper extension portion (3241a) via spokes (3242); An integral conical portion (3245b) is provided at the lower end of the inner cylinder (3245), and a drainage hole (3245c) is provided on one side of the inner cylinder (3245); A steam inlet pipe (3246) is installed on one side of the second lower extension portion (3245d), and the other end of the steam inlet pipe (3246) is fixedly connected to a steam joint (363); A second drainage hole (3245e) is provided on one side of the second lower extension portion (3245d); Water that enters the housing (321) through the water supply joint (323) enters the reversing valve (360) through the water inlet head (362).

9. The molten salt energy storage and heat exchange device according to claim 8, characterized in that: An overflow hole (321a) is provided on one side of the housing (321), and the height of the overflow hole (321a) is lower than the height of the second drainage hole (3245e); A connecting rod (370) passes through the overflow hole (321a); ​​a sealing plate 1 (370a) is fixedly provided on the side of the connecting rod (370) located inside the housing (321); and a sealing plate 2 (370b) is fixedly provided on the side of the connecting rod (370) located outside the housing (321); One end of the connecting rod (370) is fixedly connected to the piston rod of the driving cylinder (350); When the vertical valve hole 1 (367a) and the vertical valve hole 2 (367b) are working, the sealing plate 1 (370a) blocks the overflow hole (321a); ​​when the drain valve hole (367c) is working, the overflow hole (321a) is in an open state; when the inclined hole 1 (367d) and the inclined hole 2 (367e) are working, the sealing plate 2 (370b) blocks the overflow hole (321a).

10. The molten salt energy storage and heat exchange device according to any one of claims 3 to 9, characterized in that: It also includes a temperature sensor 1 (391) and a temperature sensor 2 (392), wherein the temperature sensor 1 (391) is fixed to one end of the heat exchange tube group (340) close to the storage tube 1 (341), and the temperature sensor 2 (392) is fixed to one end of the heat exchange tube group (340) close to the storage tube 2 (342), and is used to detect the temperature of the high-temperature molten salt on both sides of the heat exchange tube group (340); The detection results of the temperature sensor 1 (391) and the temperature sensor 2 (392) are transmitted to the controller, and the controller controls the operation of the spent liquid reflux pump (12).

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