Steam supply system and method for molten salt industry

Abstract

This invention discloses a steam supply system and method for molten salt industry. The molten salt industry steam supply system includes a water supply component, a pressure reducing and expanding vessel, a heater, a photovoltaic power station, and a heat exchanger. The water supply component generates boiler feedwater and is adapted to be connected to the boiler so that the boiler feedwater flowing out of the water supply component can flow into the boiler. The pressure reducing and expanding vessel is connected to the water supply component so that the boiler feedwater flowing out of the water supply component can flow into the pressure reducing and expanding vessel to be converted into saturated steam. The heater is adapted to heat molten salt to a high temperature. The photovoltaic power station is used to generate electricity using solar energy and is electrically connected to the heater so that the photovoltaic power station can provide power to the heater. One end of the heat exchanger is connected to both the heater and the pressure reducing and expanding vessel, and the other end of the heat exchanger is connected to both the heater and the industrial system. The molten salt industry steam supply system of this invention has the advantages of high steam supply capacity, low cost, and long service life.

Description

Technical Field

[0001] This invention discloses the field of energy and energy-saving technology, specifically relating to a steam supply system and method for molten salt industry. Background Technology

[0002] For cogeneration retrofitting, high-parameter industrial steam supply has always been a key and challenging area, especially for industrial steam supply above 3.5MPa. There are few steam extraction points in the thermal system to choose from, and the means of steam supply are very limited, which has created a bottleneck for expanding cogeneration.

[0003] Among related technologies, industrial steam supply has limited steam volume, poor steam quality, and poor reliability. Summary of the Invention

[0004] This invention is based on the inventor's discoveries and understanding of the following facts and problems:

[0005] In related technologies, desuperheating and pressure reduction are achieved through methods such as superheated steam extraction, steam extraction via the supplementary gas regulating valve, and No. 0 steam extraction. However, due to the overheating limitation of the reheater, the actual steam extraction volume is limited. Combined with deep peak shaving of the unit, the steam supply capacity drops sharply at low loads, severely affecting the quality and reliability of the steam supply. Conventional methods such as central valve-assisted reheating and steam supply, connecting pipe extraction, and rotating diaphragms are insufficient to meet the steam supply pressure requirements across a wide load range, resulting in low steam supply pressure. Other technologies, such as steam ejection, are ill-suited to the current power situation where units frequently participate in deep peak shaving, exhibiting poor variable operating condition capabilities. Therefore, all related technologies have certain limitations, hindering the development of combined heat and power (CHP).

[0006] The present invention aims to at least partially solve one of the technical problems in the related art.

[0007] Therefore, embodiments of the present invention propose a molten salt industrial steam supply system with sufficient steam supply and long service life.

[0008] This invention proposes an industrial steam supply method that is simple in structure and low in cost.

[0009] A molten salt industrial steam supply system according to an embodiment of the present invention includes: a water supply assembly for generating boiler feedwater, the water supply assembly being adapted to be connected to a boiler so that the boiler feedwater flowing out of the water supply assembly flows into the boiler; a pressure reducing and expanding vessel, the pressure reducing and expanding vessel being connected to the water supply assembly so that the boiler feedwater flowing out of the water supply assembly flows into the pressure reducing and expanding vessel to convert the boiler feedwater into saturated steam after pressure reduction and expansion; a heater and a photovoltaic power station, the heater being adapted to heat molten salt to a high temperature, the photovoltaic power station being used to generate electricity using solar energy, the photovoltaic power station being electrically connected to the heater so that the photovoltaic power station provides electrical energy to the heater; and a heat exchanger, one end of the heat exchanger being connected to both the heater and the pressure reducing and expanding vessel so that the molten salt heated by the heater and the saturated steam flowing out of the pressure reducing and expanding vessel both flow into the heat exchanger so that the molten salt heats the saturated steam, the other end of the heat exchanger being connected to the heater and an industrial system so that the molten salt heated by the heat exchanger flows into the heater and the saturated steam heated by the heat exchanger flows into the industrial system.

[0010] The molten salt industrial steam supply system of this invention includes a pressure-reducing expansion vessel, a heater, a photovoltaic power station, and a heat exchanger. It eliminates the need for superheated steam extraction and allows boiler feedwater to be directly introduced into the inlet of the pressure-reducing expansion vessel as needed. This increases the amount of steam supplied to the industrial system, thereby improving its steam supply capacity and ensuring the steam flow rate into the reheater within the boiler. This solves the problem of overheating caused by an imbalance in the flow rates between the superheater and reheater after a large amount of main steam is extracted from the main steam of medium and large-sized cogeneration units, leading to a decrease in the reheater inlet steam flow rate.

[0011] In some embodiments, the molten salt industrial steam supply system further includes: a low-temperature molten salt tank, which is connected to the heat exchanger so that molten salt after heat exchange by the heat exchanger flows into the low-temperature molten salt tank, and the low-temperature molten salt tank is connected to the heater so that molten salt flowing out of the low-temperature molten salt tank flows into the heater so that the heater heats the molten salt; and a high-temperature molten salt tank, which is connected to the heater so that molten salt after heat exchange by the heater flows into the high-temperature molten salt tank, and the high-temperature molten salt tank is connected to the heat exchanger so that molten salt flowing out of the high-temperature molten salt tank flows into the heat exchanger.

[0012] In some embodiments, the molten salt industrial steam supply system further includes a temperature measuring device, which is mounted on and connected to the high-temperature molten salt tank so that the temperature measuring device can detect the temperature inside the high-temperature molten salt tank.

[0013] In some embodiments, the molten salt industrial steam supply system further includes an energy storage component, which is electrically connected to the photovoltaic power station and the heater, respectively. The energy storage component has a first state and a second state. In the first state, the power required by the heater is less than the output power of the photovoltaic power station, and the excess electrical energy of the photovoltaic power station is stored in the energy storage component. In the second state, the power required by the heater is greater than the output power of the photovoltaic power station, and the energy storage component replenishes the electrical energy of the heater.

[0014] In some embodiments, the molten salt industrial steam supply system further includes: a boiler, the water supply assembly for generating boiler feedwater, the boiler and the water supply assembly being connected so that the boiler feedwater flowing out of the water supply assembly flows into the boiler, the boiler being used to heat the water supply assembly into steam; and a steam turbine, one end of the steam turbine being connected to the boiler so that the steam flowing out of the boiler flows into the steam turbine to drive the steam turbine to do work, and the other end of the steam turbine being connected to the water supply assembly so that the steam after the steam turbine has done work flows into the water supply assembly so that the water supply assembly converts the steam into boiler feedwater.

[0015] In some embodiments, the molten salt industrial steam supply system further includes: a high-temperature molten salt pump, which is connected to both the heat exchanger and the high-temperature molten salt tank, so that molten salt in the high-temperature molten salt tank flows into the heat exchanger through the high-temperature molten salt pump; and a low-temperature molten salt pump, which is connected to both the high-temperature molten salt tank and the low-temperature molten salt tank, so that molten salt in the low-temperature molten salt tank flows into the high-temperature molten salt tank through the low-temperature molten salt pump.

[0016] In some embodiments, the molten salt industrial steam supply system further includes a reheater and a superheater, both of which are located within the boiler. The superheater is adapted to receive boiler feedwater so that it heats the boiler feedwater into superheated steam. Both the superheater and the reheater are connected to the steam turbine so that the superheated steam flowing out of the superheater and the reheated steam flowing out of the reheater both flow into the steam turbine to enable the steam turbine to perform work.

[0017] In some embodiments, the steam turbine includes a high-pressure cylinder, an intermediate-pressure cylinder, and a low-pressure cylinder connected in sequence. The high-pressure cylinder is connected to the superheater so that superheated steam flowing out of the superheater flows into the high-pressure cylinder to do work. The high-pressure cylinder is connected to the reheater so that superheated steam flowing out of the high-pressure cylinder flows into the reheater to heat the superheated steam into reheated steam. The reheater is connected to the intermediate-pressure cylinder so that reheated steam flowing out of the reheater flows into the intermediate-pressure cylinder.

[0018] An industrial steam supply system method according to an embodiment of the present invention is characterized by comprising:

[0019] S1: Reduce the pressure and expand the capacity of the boiler feedwater to convert the boiler feedwater into saturated steam;

[0020] S2: Use a heater to heat the molten salt to a high temperature;

[0021] S3: Use a heat exchanger to exchange heat between the high-temperature molten salt and the saturated steam, so that the high-temperature molten salt heats the saturated steam to a preset temperature;

[0022] S4: The heated saturated steam is introduced into the industrial system.

[0023] In some embodiments, in step S2, the heater is powered by a photovoltaic power station. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the molten salt industrial steam supply system according to an embodiment of the present invention.

[0025] 100 molten salt industrial steam supply system;

[0026] Boiler 1;

[0027] Steam turbine 2; high-pressure cylinder 21; intermediate-pressure cylinder 22; low-pressure cylinder 23;

[0028] Water supply assembly 3; high-pressure heater 31; deaerator 32; feedwater pump 33; low-pressure heater 34; condensate pump 35; condenser 36;

[0029] 4. Butterfly valve for connecting pipe of medium and low pressure cylinder; 5. First isolation valve; 6. Photovoltaic power station; 7. Cryogenic molten salt tank; 8. Pressure reducing expansion tank; 9. Cryogenic molten salt pump; 10. Heat exchanger; 11. Sixth isolation valve; 12. Second isolation valve;

[0030] Heater 13; High-temperature molten salt tank 14; High-temperature molten salt pump 15; Energy storage transformer 16; High-temperature transformer 17; Third isolation valve 18; Temperature measuring device 19; Fourth isolation valve 20; Fifth isolation valve 21;

[0031] Reheater 22; Superheater 23. Detailed Implementation

[0032] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0033] A molten salt industrial steam supply system 100 according to an embodiment of the present invention is described below with reference to the accompanying drawings.

[0034] like Figure 1 As shown, the molten salt industrial steam supply system 100 according to an embodiment of the present invention includes a water supply assembly 3, a pressure reducing expansion vessel 8, a heater 13, a photovoltaic power station 6, and a heat exchanger 10.

[0035] The water supply assembly 3 is used to generate boiler feedwater. The water supply assembly 3 is adapted to be connected to the boiler 1 so that the boiler feedwater flowing out of the water supply assembly 3 flows into the boiler 1. Specifically, as shown... Figure 1 As shown, the water supply component 3 can generate boiler feedwater, and the boiler 1 can be connected to the water supply component 3 to heat the boiler feedwater into steam for the steam turbine 2 to do work.

[0036] The pressure-reducing expansion tank 8 is connected to the water supply assembly 3 so that the boiler feedwater flowing out of the water supply assembly 3 flows into the pressure-reducing expansion tank 8, thereby converting the boiler feedwater into saturated steam after pressure reduction and expansion. Specifically, as follows... Figure 1 As shown, the pressure reducing and expansion vessel 8 can be a pressure reducing and expansion device with good sealing performance and strong heat insulation performance. Boiler feedwater can be introduced into the inlet of the pressure reducing and expansion vessel. The boiler feedwater is converted into saturated steam in the pressure reducing and expansion vessel 8, so that the boiler feedwater generated by the water supply component 3 is divided into two parts, one part flows into the boiler 1 and the other part flows into the pressure reducing and expansion vessel.

[0037] Heater 13 is suitable for heating molten salt to a high temperature. Photovoltaic power station 6 is used to generate electricity using solar energy. Photovoltaic power station 6 is electrically connected to heater 13 so that photovoltaic power station 6 provides power to heater 13. Specifically, as... Figure 1 As shown, heater 13 can be a molten salt heater 13, and photovoltaic power station 6 can be a distributed photovoltaic power generation system. Photovoltaic power station 6 is electrically connected to heater 13, so that photovoltaic power station 6 supplies power to heater 13, thereby enabling heater 13 to convert electrical energy into heat energy to heat the molten salt to a high temperature.

[0038] One end of the heat exchanger 10 is connected to both the heater 13 and the pressure-reducing expansion vessel 8, so that the molten salt heated by the heater 13 and the saturated steam flowing out of the pressure-reducing expansion vessel 8 both flow into the heat exchanger 10 to heat the saturated steam with the molten salt. The other end of the heat exchanger 10 is connected to both the heater 13 and the industrial system, so that the molten salt after heat exchange in the heat exchanger 10 flows into the heater 13 and the saturated steam heated by the heat exchanger 10 flows into the industrial system. Specifically, as... Figure 1As shown, the heat exchanger 10 includes a first channel (not shown in the figure) and a second channel (not shown in the figure) for heat exchange. The inlet of the first channel is connected to the outlet of the pressure reducing expansion vessel 8, so that the saturated steam generated by the pressure reducing expansion vessel 8 flows into the first channel. The inlet of the second channel is connected to the outlet of the heater 13, so that the high-temperature molten salt heated by the heater 13 flows into the second channel, thereby exchanging heat between the saturated steam in the first channel and the high-temperature molten salt in the second channel. The temperature of the saturated steam in the first channel increases, and the temperature of the high-temperature molten salt in the second channel decreases to that of low-temperature molten salt. The outlet of the first channel is connected to the industrial system, thereby providing high-temperature steam to the industrial system. The outlet of the second channel is connected to the heater 13, thereby allowing the low-temperature molten salt to flow into the heater 13 for heating.

[0039] The molten salt industrial steam supply system 100 of this invention uses a photovoltaic power station 6 and a heater 13 to heat molten salt. The high-temperature molten salt serves as a high-temperature heat source, drawing boiler feedwater from the outlet of the water supply component 3 and passing it through a pressure reducing and expanding vessel 8 to the required steam pressure. The high-temperature molten salt then heats the saturated steam to superheated steam at the required temperature. This invention allows the unit to significantly increase its industrial steam supply capacity and expand its heating range based on existing steam supply schemes such as main steam extraction and supplementary steam valve supply, thereby enhancing its market competitiveness and heating economy. Furthermore, the molten salt energy storage system can also be used as a start-up boiler 1.

[0040] The molten salt industrial steam supply system 100 of this invention includes a pressure-reducing expansion vessel 8, a heater 13, and a heat exchanger 10. Boiler feedwater is depressurized and expanded through the pressure-reducing expansion vessel 8 to form saturated steam. Molten salt is heated to a high temperature through the heater 13, and the heated high-temperature molten salt is then heated to the required temperature of the industrial system through the heat exchanger 10. Compared with related technologies, there is no need to extract superheated steam. Boiler feedwater can be directly introduced into the inlet of the pressure-reducing expansion vessel 8 according to actual needs, which increases the amount of steam supplied to the industrial system and thus improves the steam supply capacity of the industrial system. It also ensures the steam flow rate of the reheater 22 in the boiler 1, thereby solving the problem of overheating caused by the imbalance of the flow rates of the superheater 23 and the reheater 22 after a large amount of main steam is extracted from the main steam of medium and large cogeneration units. This ensures the service life of the reheater 22.

[0041] In some embodiments, the molten salt industrial steam supply system 100 further includes a cryogenic molten salt tank 7 and a high-temperature molten salt tank 14.

[0042] The cryogenic molten salt tank 7 is connected to the heat exchanger 10 so that the molten salt after heat exchange in the heat exchanger 10 flows into the cryogenic molten salt tank 7. The cryogenic molten salt tank 7 is connected to the heater 13 so that the molten salt flowing out of the cryogenic molten salt tank 7 flows into the heater 13 so that the heater 13 heats the molten salt. Specifically, as shown in... Figure 1As shown, the inlet of the low-temperature molten salt tank 7 is connected to the outlet of the second channel of the heat exchanger 10, so that the low-temperature molten salt flowing out of the heat exchanger 10 flows into the low-temperature molten salt tank 7 for storage. The outlet of the low-temperature molten salt tank 7 is connected to the heater 13, so that the low-temperature molten salt in the low-temperature molten salt tank 7 is heated to high-temperature molten salt by the heater 13.

[0043] The high-temperature molten salt tank 14 is connected to the heater 13 so that the molten salt heated by the heater 13 flows into the high-temperature molten salt tank 14. The high-temperature molten salt tank 14 is connected to the heat exchanger 10 so that the molten salt flowing out of the high-temperature molten salt tank 14 flows into the heat exchanger 10. Specifically, as shown... Figure 1 As shown, the outlet of heater 13 is connected to the inlet of high-temperature molten salt tank 14. The high-temperature molten salt heated by heater 13 flows into high-temperature molten salt tank 14 for storage. The outlet of high-temperature molten salt tank 14 is connected to the inlet of the second channel of heat exchanger 10. The high-temperature molten salt generated by high-temperature molten salt tank 14 flows into the second channel of heat exchanger 10 to heat the saturated steam in the first channel.

[0044] In some embodiments, the molten salt industrial steam supply system 100 further includes a temperature measuring device 19, which is mounted on and connected to the high-temperature molten salt tank 14 to detect the temperature inside the high-temperature molten salt tank 14. Thus, by detecting the temperature inside the high-temperature molten salt tank 14, when the temperature inside the high-temperature molten salt tank 14 is lower than a preset value, the molten salt inside the high-temperature molten salt tank 14 can be flowed into the low-temperature molten salt tank 7, thereby heating the high-temperature molten salt to the preset temperature via the heater 13.

[0045] In some embodiments, the molten salt industrial steam supply system 100 further includes an energy storage component, which is electrically connected to the photovoltaic power station 6 and the heater 13, respectively. The energy storage component has a first state and a second state. In the first state, the power required by the heater 13 is less than the output power of the photovoltaic power station 6, and the excess electrical energy of the photovoltaic power station 6 is stored in the energy storage component. In the second state, the power required by the heater 13 is greater than the output power of the photovoltaic power station 6, and the energy storage component replenishes the electrical energy of the heater 13. Specifically, as shown... Figure 1 As shown, the energy storage component includes a high-voltage transformer 17 and an energy storage transformer 16. In the first state, the power generation bus of the photovoltaic power station 6 is connected to the energy storage transformer 16 or the high-voltage transformer 17. When the photovoltaic power station 6 generates too much electricity, it can store the electricity in the high-voltage transformer 17 and the energy storage transformer 16. In the second state, both the high-voltage transformer 17 and the energy storage transformer 16 are connected to the heater 13. When the electricity generated by the photovoltaic power station 6 is insufficient to maintain the normal operation of the heater 13, the high-voltage transformer 17 and the energy storage transformer 16 can supply power to the heater 13 to ensure the normal operation of the heater 13. This allows the molten salt in the low-temperature molten salt tank 7 to enter the electric heater 13 and be heated into high-temperature molten salt, which then flows into the high-temperature molten salt tank 14 and is maintained at the set temperature.

[0046] The molten salt industrial steam supply system 100 also includes: a boiler 1 and a steam turbine 2.

[0047] Water supply assembly 3 is used to generate boiler feedwater. Boiler 1 and water supply assembly 3 are connected so that the boiler feedwater flowing out of water supply assembly 3 flows into boiler 1. Boiler 1 is used to heat water supply assembly 3 into steam. One end of steam turbine 2 is connected to boiler 1 so that the steam flowing out of boiler 1 flows into steam turbine 2 to drive steam turbine 2 to do work. The other end of steam turbine 2 is connected to water supply assembly 3 so that the steam after steam turbine 2 has done work flows into water supply assembly 3 so that water supply assembly 3 can convert steam into boiler feedwater. Specifically, as follows... Figure 1 As shown, boiler 1 heats boiler feedwater into steam. The inlet of turbine 2 is connected to the outlet of boiler 1, allowing the superheated steam generated by boiler 1 to flow into turbine 2. Turbine 2 can utilize the superheated steam to rotate, converting the internal energy of the superheated steam into mechanical energy. The outlet of turbine 2 is connected to the inlet of water supply assembly 3, allowing the superheated steam after turbine 2 has done work to flow into water supply assembly 3. Water supply assembly 3 can convert the steam after work into boiler feedwater. The outlet of water supply assembly 3 is connected to boiler 1 and pressure reducing expansion tank 8, respectively, thus allowing boiler feedwater to flow into boiler 1 and pressure reducing expansion tank 8.

[0048] The molten salt industrial steam supply system 100 also includes a reheater 22 and a superheater 23. Both the superheater 23 and the reheater 22 are located inside the boiler 1. The superheater 23 is adapted to receive boiler feedwater so that it heats the boiler feedwater into superheated steam. Both the superheater 23 and the reheater 22 are connected to the steam turbine 2 so that the superheated steam flowing out of the superheater 23 and the reheated steam flowing out of the reheater 22 both flow into the steam turbine 2 so that the steam turbine 2 can perform work. The steam turbine 2 includes a high-pressure cylinder 21, an intermediate-pressure cylinder 22, and a low-pressure cylinder 23 connected in sequence. The high-pressure cylinder 21 is connected to the superheater 23 so that the superheated steam flowing out of the superheater 23 flows into the high-pressure cylinder 21 to do work. The high-pressure cylinder 21 is connected to the reheater 22 so that the superheated steam flowing out of the high-pressure cylinder 21 flows into the reheater 22 to be heated into reheated steam. The reheater 22 is connected to the intermediate-pressure cylinder 22 so that the reheated steam flowing out of the reheater 22 flows into the intermediate-pressure cylinder 22. Specifically, as shown... Figure 1 As shown, specifically, as Figure 1As shown, the inlet of superheater 23 can be supplied with boiler feedwater, which can be heated by superheater 23 to become superheated steam. The inlet of high-pressure cylinder 21 is connected to the outlet of superheater 23, and the superheated steam generated in superheater 23 flows into high-pressure cylinder 21 to do work. The outlet of high-pressure cylinder 21 is connected to the inlet of reheater 22, and the superheated steam flowing out after doing work in high-pressure cylinder 21 flows into reheater 22 for secondary heating to form reheated steam. The outlet of reheater 22 is connected to intermediate-pressure cylinder 22, and the outlet of intermediate-pressure cylinder 22 is connected to the inlet of low-pressure cylinder 23. The reheated steam flowing out after doing work in intermediate-pressure cylinder 22 flows into low-pressure cylinder 23 to do further work. Thus, by doing work step by step through high-pressure cylinder 21, intermediate-pressure cylinder 22 and low-pressure cylinder 23, the utilization rate of reheated steam is improved. The outlet of the low-pressure cylinder 23 is connected to the inlet of the feedwater assembly, so that the steam after the low-pressure cylinder 23 has done work flows into the feedwater assembly to convert the steam into boiler feedwater, thereby recovering the steam, saving water resources, and making the steam supply system 100 for the molten salt industry more reasonable.

[0049] In some embodiments, the water supply assembly 3 includes a condenser 36, a deaerator 32, and a heater 13.

[0050] Condenser 36 is connected to turbine 2 so that steam flowing out of turbine 2 flows into condenser 36 to convert steam into condensate. Deaerator 32 is connected to condenser 36 so that condensate flowing out of condenser 36 flows into deaerator 32 to remove oxygen from condensate. Heater 13 is connected to deaerator 32 so that condensate flowing out of deaerator 32 is heated to become boiler feedwater. Heater 13 is connected to both boiler 1 and pressure-reducing expansion tank 8 so that boiler feedwater flowing out of heater 13 flows into both boiler 1 and pressure-reducing expansion tank 8.

[0051] Specifically, such as Figure 1 As shown, the water supply assembly 3 includes a condenser 36, a condensate pump 35, a low-pressure heater 34, a feedwater pump 33, a deaerator 32, and a high-pressure heater 31 connected in sequence (wherein, heater 13 includes a low-pressure heater 34 and a high-pressure heater 31). Thus, the reheat steam flowing out of the low-pressure cylinder 23 of the turbine 2 is converted into boiler feedwater by passing through the condenser 36, condensate pump 35, low-pressure heater 34, feedwater pump 33, deaerator 32, and high-pressure heater 31 in sequence. The outlet of the high-pressure heater 31 is connected to the inlet of the boiler 1 and the inlet of the pressure reducing expansion tank 8, respectively. This causes the boiler feedwater flowing out of the high-pressure heater 31 to be divided into two streams, one of which flows into the superheater 23 of the boiler 1, and the other of which flows into the pressure reducing expansion tank 8. Thus, the boiler 1, the turbine 2, and the water supply assembly 3 complete a thermodynamic cycle, making the industrial steam supply system more rationally configured.

[0052] The molten salt industrial steam supply system 100 also includes a high-temperature molten salt pump 15 and a low-temperature molten salt pump 9.

[0053] The high-temperature molten salt pump 15 is connected to both the heat exchanger 10 and the high-temperature molten salt tank 14, so that the molten salt in the high-temperature molten salt tank 14 flows into the heat exchanger 10 through the high-temperature molten salt pump 15. Specifically, as shown... Figure 1 As shown, the inlet of the high-temperature molten salt pump 15 is connected to the outlet of the high-temperature molten salt tank 14, and the outlet of the high-temperature molten salt pump 15 is connected to the inlet of the second channel of the heat exchanger 10. Thus, the high-temperature molten salt is transported to the second channel through the high-temperature molten salt pump 15, so that the high-temperature molten salt pump 15 provides power for the transport of high-temperature molten salt, and the amount flowing into the second channel can be controlled by the high-temperature molten salt pump 15, thereby controlling the temperature of the saturated steam in the first channel.

[0054] The cryogenic molten salt pump 9 is connected to both the high-temperature molten salt tank 14 and the cryogenic molten salt tank 7, so that the molten salt in the cryogenic molten salt tank 7 flows into the high-temperature molten salt tank 14 through the cryogenic molten salt pump 9. Specifically, as shown... Figure 1 As shown, the inlet of the cryogenic molten salt pump 9 is connected to the outlet of the cryogenic molten salt tank 7, and the outlet of the cryogenic molten salt pump 9 is connected to the inlet of the heater 13. Thus, the cryogenic molten salt is transported to the heater 13 through the cryogenic molten salt pump 9, so that the cryogenic molten salt pump 9 provides power for the transport of cryogenic molten salt.

[0055] The molten salt industrial steam supply system 100 also includes a medium and low pressure cylinder connecting pipe butterfly valve 4, a first isolation valve 5, a second isolation valve 12, a third isolation valve 18, a fourth isolation valve 20, a fifth isolation valve 21, and a sixth isolation valve 11.

[0056] The inlet and outlet of the butterfly valve 4 connecting the intermediate and low-pressure cylinders are connected to the outlet of the intermediate-pressure cylinder 22 and the inlet of the low-pressure cylinder 23, respectively. Thus, the butterfly valve 4 controls the on / off state of the intermediate-pressure cylinder 22 and the low-pressure cylinder 23, as well as the flow rate of steam into the low-pressure cylinder 23.

[0057] The inlet and outlet of the first isolation valve 5 are connected to the outlet of the water supply component 3 and the inlet of the pressure reducing and expanding container 8, respectively. Thus, the on / off connection between the water supply component 3 and the pressure reducing and expanding container 8 is controlled by the first isolation valve.

[0058] The inlet and outlet of the second isolation valve 12 are connected to the outlet of the high-temperature molten salt pump 15 and the inlet of the second channel of the heat exchanger 10, respectively. Thus, the on / off state of the high-temperature molten salt pump 15 and the heat exchanger 10 is controlled by the second isolation valve 12.

[0059] The inlet and outlet of the third isolation valve 18 are connected to the outlet of the first channel of the heat exchanger 10 and the inlet of the industrial system, respectively. Thus, the on / off connection between the heat exchanger 10 and the first channel is controlled by the third isolation valve 18.

[0060] The inlet and outlet of the fourth isolation valve 20 are connected to the outlet of the high-temperature molten salt pump 15 and the inlet of the low-temperature molten salt tank 7, respectively. Thus, the fourth isolation valve 20 controls the connection and disconnection between the high-temperature molten salt pump 15 and the low-temperature molten salt tank 7. When the temperature in the high-temperature molten salt tank 14 is lower than the preset value or there is too much molten salt in the high-temperature molten salt tank 14, the high-temperature molten salt pump 15 and the fourth isolation valve can be opened to allow the molten salt in the high-temperature molten salt tank 14 to flow into the low-temperature molten salt tank 7.

[0061] The inlet and outlet of the fifth isolation valve 2128 are connected to the outlet of the second channel of the heat exchanger 10 and the inlet of the cryogenic molten salt tank 7, respectively. Thus, the connection and disconnection between the heat exchanger 10 and the cryogenic molten salt tank 7 are controlled by the fifth isolation valve 21.

[0062] The inlet and outlet of the sixth isolation valve 11 are connected to the outlet of the cryogenic molten salt tank 7 and the inlet of the heater 13, respectively. Thus, the connection and disconnection between the cryogenic molten salt tank 7 and the heater 13 are controlled by the sixth isolation valve 11.

[0063] The working process of the molten salt industrial steam supply system 100 in this embodiment of the invention is as follows:

[0064] 1) Photovoltaic power station 6 is connected to both energy storage transformer and high-voltage transformer 17, and can supply power to both at the same time;

[0065] 2) When starting high-parameter industrial steam supply, open the first isolation valve 5, the third isolation valve 18 and the pressure reducing expansion vessel 8 in sequence, close the fourth isolation valve 20, and open the second isolation valve 12 and the fifth isolation valve 21.

[0066] 3) The boiler feedwater outlet is divided into two paths. One path enters the inlet of the pressure reducing expansion vessel 8 through the first isolation valve 5, and the other path enters the superheater 23 of the boiler 1. After being heated into high-temperature and high-pressure superheated steam, it enters the high-pressure cylinder 21 to do work.

[0067] 4) Start the cryogenic molten salt pump 9, the sixth isolation valve 11, the high-temperature molten salt pump 15, and the second isolation valve 12;

[0068] 5) The exhaust steam from the high-pressure cylinder 21 re-enters the boiler 1 for secondary heating, and the reheated steam from the outlet enters the intermediate-pressure cylinder 22 to perform work.

[0069] 6) The exhaust steam from the intermediate pressure cylinder 22 enters the low pressure cylinder 23 through the butterfly valve 4 of the intermediate-low pressure cylinder connecting pipe to perform work;

[0070] 7) The saturated steam at the outlet of the pressure reducing and expansion vessel 8 enters the heat exchanger 10 to exchange heat with the high-temperature molten salt. The outlet of the heat exchanger 10 is connected to the high-pressure industrial steam supply system after passing through the third isolation valve 18.

[0071] 8) The exhaust steam from the low-pressure cylinder 23 enters the condenser 36 for condensation. The condensate is pumped by the condensate pump 35 and then passes through the low-pressure heater 34, deaerator 32 and high-pressure heater 31 in sequence, and is divided into two paths. One path enters the superheater 23 of the boiler 1 and is heated into superheated steam. The other path enters the first isolation valve 5 and the pressure reducing expansion vessel 8 and becomes saturated steam.

[0072] 9) The molten salt in the low-temperature molten salt tank 7 enters the electric heater 13 after passing through the low-temperature molten salt pump 9 and the sixth isolation valve 11, and becomes a high-temperature heat source. After passing through the high-temperature heat source pump and the second isolation valve 12, it enters the heat exchanger 10 to exchange heat with high-pressure saturated wet steam. After cooling, the molten salt enters the electric heater 13 for reheating.

[0073] 10) Adjust the required high-pressure steam supply flow rate by adjusting the first isolation valve 5;

[0074] 11) Adjust the pressure reducing and expansion vessel 8 to regulate the required high-pressure steam supply pressure;

[0075] 12) Adjust the high-temperature molten salt pump 15 to regulate the steam supply temperature;

[0076] 13) The electric heater 13 is connected to both the newly added energy storage transformer and the photovoltaic power station 17. Both can supply power to the heat exchanger 10. (If the power required by the heat exchanger 10 is less than the output power of the photovoltaic power station 6, the excess power is sent to the photovoltaic power station 17. Conversely, if the power required by the heat exchanger 10 is greater than the output power of the photovoltaic power station 6, the insufficient part is supplemented by the photovoltaic power station 17.)

[0077] When high-parameter industrial steam supply stops

[0078] 14) Close the valve of electric heater 13;

[0079] 15) Close the first isolation valve 5, the third isolation valve 18, the pressure reducing expansion vessel 8, the second isolation valve 12, and the fifth isolation valve 21;

[0080] 16) The unit operates in normal pure condensing mode. The main steam from the boiler 1 outlet enters the high-pressure cylinder 21 to do work, and the exhaust steam re-enters the boiler 1 for secondary heating. The reheated steam from the outlet enters the intermediate-pressure cylinder 22 to do work. At this time, the butterfly valve 4 of the connecting pipe between the intermediate and low-pressure cylinders is fully open, and the exhaust steam from the intermediate-pressure cylinder 22 enters the low-pressure cylinder 23 to do work. The exhaust steam enters the condenser 36 for condensation. The condensate passes through the condensate pump 35, then through the low-pressure heater 34, and enters the deaerator 32. Finally, it is pressurized by the feedwater pump 33, passes through the high-pressure heater 31, and enters the boiler 1 for heating. After becoming high-temperature steam, it enters the high-pressure cylinder 21 to continue doing work, completing the thermodynamic cycle.

[0081] In summary, the molten salt industrial steam supply system 100 of this invention has the following advantages:

[0082] [1] The molten salt industrial steam supply system 100 of the present invention does not need to directly extract steam from the thermal system, and has high safety and strong stability.

[0083] [2] The molten salt industrial steam supply system 100 of the present invention improves the high-parameter industrial steam supply capacity of the unit and improves the economic efficiency of the unit.

[0084] [3] The molten salt industrial steam supply system 100 of this embodiment does not require modification of the boiler 1 and the turbine 2. It only requires the addition of some valves and a first-stage heat exchanger 10 to achieve a more than doubling of the high-parameter industrial steam supply capacity without affecting the safety of the main unit.

[0085] [4] The molten salt industrial steam supply system 100 of this embodiment of the invention is flexible in operation and can adjust the industrial steam supply pressure according to user needs. It has a wide range of applications and can meet the steam supply needs of different levels of industry. In addition, the newly added industrial energy storage system can replace the power plant to start the boiler 1, simplifying the equipment system.

[0086] The industrial steam supply system method according to embodiments of the present invention includes:

[0087] S1: The boiler feedwater is depressurized and expanded to convert it into saturated steam. Specifically, the boiler feedwater is divided into two streams. One stream is depressurized and expanded through the pressure reducing and expansion vessel 8 to form saturated steam, while the other stream flows into the boiler 1 and is heated to form reheat steam or superheated steam. Thus, superheated steam in the boiler 1 is not required to flow into the industrial system, thereby ensuring the flow rate of the reheater 22 in the boiler 1, preventing the reheater 22 from overheating, and ensuring the service life of the reheater 22.

[0088] S2: The molten salt is heated to a high temperature using heater 13. S3: The high-temperature molten salt and saturated steam are exchanged using heat exchanger 10, so that the high-temperature molten salt heats the saturated steam to a preset temperature. S4: The heated saturated steam is then introduced into the industrial system. Specifically, the molten salt is heated to a high temperature by heater 13 and flows into heat exchanger 10. Heat exchanger 10 allows the high-temperature molten salt to exchange heat with the saturated steam, increasing the temperature of the saturated steam for supplying steam to the industrial system.

[0089] The industrial steam supply method of this invention has the advantages of simple steps, strong industrial steam supply capacity, and stable, reliable, and high-parameter industrial steam supply over a wide load range.

[0090] In some embodiments, in step S2, the photovoltaic power station 6 supplies power to the heater 13. This allows the electricity generated by the photovoltaic power station 6 to power the heater 13, reducing the heating cost of industrial steam supply methods.

[0091] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0092] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0093] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0094] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0095] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0096] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A steam supply system for molten salt industry, characterized in that, include: A water supply assembly is provided for generating boiler feedwater. The water supply assembly is adapted to be connected to the boiler so that the boiler feedwater flowing out of the water supply assembly flows into the boiler. The water supply assembly includes a condenser, a condensate pump, a low-pressure heater, a feedwater pump, a deaerator, and a high-pressure heater connected in sequence. The outlet of the high-pressure heater is connected to the inlet of the boiler and the inlet of the pressure reducing expansion tank, so that the boiler feedwater flowing out of the high-pressure heater flows into the boiler and the pressure reducing expansion tank, respectively. A pressure-reducing expansion vessel is connected to the water supply assembly so that boiler feedwater flowing out of the water supply assembly flows into the pressure-reducing expansion vessel so that the boiler feedwater is converted into saturated steam after pressure reduction and expansion. A heater and a photovoltaic power station, wherein the heater is adapted to heat molten salt to a high temperature, and the photovoltaic power station is used to generate electricity using solar energy, and the photovoltaic power station is electrically connected to the heater so that the photovoltaic power station provides electrical energy to the heater; A heat exchanger is provided, with one end connected to both the heater and the pressure-reducing expansion vessel, so that molten salt heated by the heater and saturated steam flowing out of the pressure-reducing expansion vessel both flow into the heat exchanger to heat the saturated steam with the molten salt. The other end of the heat exchanger is connected to both the heater and the industrial system, so that molten salt heated by the heat exchanger flows into the heater and saturated steam heated by the heat exchanger flows into the industrial system. The heat exchanger includes a first channel and a second channel for heat exchange. The inlet of the first channel is connected to the outlet of the pressure-reducing expansion vessel, allowing saturated steam generated by the pressure-reducing expansion vessel to flow into the first channel. The inlet of the second channel is connected to the outlet of the heater, allowing high-temperature molten salt heated by the heater to flow into the second channel. This allows heat exchange between the saturated steam in the first channel and the high-temperature molten salt in the second channel, increasing the temperature of the saturated steam in the first channel and decreasing the temperature of the high-temperature molten salt in the second channel to a lower temperature. The outlet of the first channel is connected to the industrial system, providing high-temperature steam to the industrial system. The outlet of the second channel is connected to the heater, allowing the low-temperature molten salt to flow into the heater for heating.

2. The molten salt industrial steam supply system according to claim 1, characterized in that, Also includes: A low-temperature molten salt tank is connected to the heat exchanger so that molten salt after heat exchange by the heat exchanger flows into the low-temperature molten salt tank. The low-temperature molten salt tank is also connected to the heater so that molten salt flowing out of the low-temperature molten salt tank flows into the heater so that the heater heats the molten salt. A high-temperature molten salt tank is connected to the heater so that molten salt heated by the heater flows into the high-temperature molten salt tank. The high-temperature molten salt tank is also connected to the heat exchanger so that molten salt flowing out of the high-temperature molten salt tank flows into the heat exchanger.

3. The molten salt industrial steam supply system according to claim 2, characterized in that, It also includes a temperature measuring device, which is installed on and connected to the high-temperature molten salt tank so that the temperature measuring device can detect the temperature inside the high-temperature molten salt tank.

4. The molten salt industrial steam supply system according to claim 1, characterized in that, It also includes an energy storage component, which is electrically connected to the photovoltaic power station and the heater respectively. The energy storage component has a first state and a second state. In the first state, the power required by the heater is less than the output power of the photovoltaic power station, and the excess electrical energy of the photovoltaic power station is stored in the energy storage component. In the second state, the power required by the heater is greater than the output power of the photovoltaic power station, and the energy storage component replenishes the electrical energy of the heater.

5. The molten salt industrial steam supply system according to claim 1, characterized in that, Also includes: A boiler, wherein the water supply assembly is used to generate boiler feedwater, the boiler and the water supply assembly are connected so that the boiler feedwater flowing out of the water supply assembly flows into the boiler, and the boiler is used to heat the boiler feedwater into steam. A steam turbine, one end of which is connected to the boiler so that steam flowing out of the boiler flows into the steam turbine to drive the steam turbine to do work, and the other end of the steam turbine is connected to the water supply assembly so that the steam after the steam turbine has done work flows into the water supply assembly so that the water supply assembly converts the steam into boiler feedwater.

6. The molten salt industrial steam supply system according to claim 2, characterized in that, Also includes: A high-temperature molten salt pump is connected to both the heat exchanger and the high-temperature molten salt tank, so that molten salt in the high-temperature molten salt tank flows into the heat exchanger through the high-temperature molten salt pump; A cryogenic molten salt pump is connected to both the high-temperature molten salt tank and the cryogenic molten salt tank, so that molten salt in the cryogenic molten salt tank flows into the high-temperature molten salt tank through the cryogenic molten salt pump.

7. The molten salt industrial steam supply system according to claim 5, characterized in that, It also includes a reheater and a superheater, both of which are located inside the boiler. The superheater is adapted to receive boiler feedwater so that it heats the boiler feedwater into superheated steam. Both the superheater and the reheater are connected to the turbine so that the superheated steam flowing out of the superheater and the reheated steam flowing out of the reheater both flow into the turbine to enable the turbine to perform work.

8. The molten salt industrial steam supply system according to claim 7, characterized in that, The steam turbine includes a high-pressure cylinder, an intermediate-pressure cylinder, and a low-pressure cylinder connected in sequence. The high-pressure cylinder is connected to the superheater so that superheated steam flowing out of the superheater flows into the high-pressure cylinder to do work. The high-pressure cylinder is connected to the reheater so that superheated steam flowing out of the high-pressure cylinder flows into the reheater to heat the superheated steam into reheated steam. The reheater is connected to the intermediate-pressure cylinder so that reheated steam flowing out of the reheater flows into the intermediate-pressure cylinder.

9. An industrial steam supply method, said method being applied to the molten salt industrial steam supply system according to any one of claims 1-8, characterized in that, include: S1: Reduce the pressure and expand the capacity of the boiler feedwater to convert the boiler feedwater into saturated steam; S2: Use a heater to heat the molten salt to a high temperature; S3: Use a heat exchanger to exchange heat between the high-temperature molten salt and the saturated steam, so that the high-temperature molten salt heats the saturated steam to a preset temperature; S4: The heated saturated steam is introduced into the industrial system.

10. The industrial steam supply method according to claim 9, characterized in that, In step S2, the heater is powered by a photovoltaic power station.

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