Cross-temperature-zone heat storage steam supply system and working method thereof

Abstract

The invention discloses a cross-temperature-zone heat storage steam supply system and a working method thereof, and belongs to the technical field of heat storage and supply. According to the system, a first inlet of a hot water storage tank is connected with an outlet of a circulating deoxidizing hot water generating unit, and a first outlet of the hot water storage tank is connected with one end of a pressure reducing throttle valve; an inlet of the molten salt hot storage tank is connected with an outlet of the molten salt cold storage tank, and an outlet of the molten salt hot storage tank is connected with a second inlet of the molten salt heat exchanger; the solid heat storage unit is connected with the solid heat storage electric heater, and an outlet of the solid heat storage unit is connected with a second inlet of the secondary overheating heater; the other end of the pressure reducing throttle valve is connected with a first inlet of the molten salt heat exchanger or the primary superheater, a first outlet of the molten salt heat exchanger or the primary superheater is connected with a first inlet of the secondary superheater, and a first outlet of the secondary superheater is connected with a steam pipe network. Hot water heat storage and vaporization can be integrated, and efficient heat supply in different temperature zones can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of heat storage and heating, and in particular to a steam supply system for cross-temperature zone heat storage and a working method thereof. Background Art

[0002] How to rationally utilize curtailed electricity and balance peak and off-peak electricity consumption have become essential technical challenges in achieving the dual carbon goals. Thermal storage systems are a highly efficient energy storage technology with broad application prospects. They temporarily store thermal energy for release when needed, enabling flexible energy allocation and efficient utilization.

[0003] Thermal storage systems can store daytime heat collected during solar thermal energy utilization for nighttime use, balance fluctuations in heat loads during industrial production, and generate steam for high power demand, allowing thermal power plants to achieve full power generation with reduced extraction. This not only improves energy efficiency and reduces energy waste, but also effectively alleviates the temporal and spatial mismatch between energy supply and demand, making it a key means of achieving sustainable energy development and energy conservation and emission reduction goals. Existing technologies cannot achieve efficient heating in temperature zones using integrated hot water storage and vaporization, molten salt, and solid multi-superheated steam, and the steam quality does not meet requirements. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a steam supply system with cross-temperature zone heat storage and its working method, which can realize the integration of hot water heat storage and vaporization, and efficient heat supply in different temperature zones of molten salt and solid multiple superheated steam.

[0005] To achieve the above object, the present invention is implemented by adopting the following technical solutions: In one aspect, the present invention provides a steam supply system for cross-temperature zone heat storage, characterized in that it includes a hot water storage tank, a molten salt heat storage tank, a solid heat storage unit and a pressure reducing throttle valve; The first inlet of the hot water storage tank is connected to the outlet of the circulating deoxygenated hot water generating unit, and the first outlet of the hot water storage tank is connected to one end of the pressure reducing throttle valve; The inlet of the molten salt hot storage tank is connected to the outlet of the molten salt cold storage tank through a molten salt electric heater, and the outlet of the molten salt hot storage tank is connected to the second inlet of the molten salt heat exchanger; The solid heat storage unit is connected to the solid heat storage electric heater, and the outlet of the solid heat storage unit is connected to the second inlet of the secondary superheat heater; The other end of the pressure reducing throttle valve is connected to the first inlet of the molten salt heat exchanger or the primary superheat heater, the first outlet of the molten salt heat exchanger or the primary superheat heater is connected to the first inlet of the secondary superheat heater, and the first outlet of the secondary superheat heater is connected to the steam pipe network.

[0006] Optionally, the circulating deoxygenated hot water generating unit includes a thermal deaerator and an electrode boiler; The outlet of the thermal deaerator is connected to the inlet of the deaeration water pump, the outlet of the deaeration water pump is connected to the inlet of the electrode boiler through the electrode boiler inlet regulating valve, and the outlet of the electrode boiler is connected to the inlet of the thermal deaerator. The thermal deaerator, the deaeration water pump, the electrode boiler inlet regulating valve, and the electrode boiler are connected end to end to form a circulating deaeration hot water loop; The inlet of the circulating deoxygenated hot water loop is connected to the outlet of the desalted water pump, and the inlet of the desalted water pump is connected to the desalted water through a water inlet control valve; The outlet of the circulating deoxygenated hot water loop is connected to the first inlet of the hot water storage tank through a hot water storage tank inlet regulating valve.

[0007] Optionally, a nitrogen pressure control unit is further included, and the nitrogen pressure control unit is installed between the second inlet and the second outlet of the hot water storage tank.

[0008] Optionally, the nitrogen pressure control unit includes a nitrogen storage tank and a nitrogen compressor; The second outlet of the hot water storage tank is connected to the inlet of the nitrogen storage tank through a first nitrogen pressure controlling valve, the outlet of the nitrogen storage tank is connected to the inlet of the nitrogen compressor, and the outlet of the nitrogen compressor is connected to the second inlet of the hot water storage tank through a second nitrogen pressure controlling valve.

[0009] Optionally, the molten salt electric heater is connected to the outlet of the cold salt pump through the cold salt storage tank outlet valve, and the inlet of the cold salt pump is connected to the outlet of the molten salt cold storage tank; The outlet of the molten salt hot storage tank is connected to the inlet of the hot salt pump, the outlet of the hot salt pump is connected to the second inlet of the molten salt heat exchanger through the hot salt storage tank outlet valve, and the second outlet of the molten salt heat exchanger is connected to the inlet of the molten salt cold storage tank.

[0010] Optionally, the inlet of the solid heat storage unit is connected to the outlet of the circulation fan; The inlet of the circulation fan is connected to the second outlet of the secondary superheat heater through the second air duct switching valve; Alternatively, the inlet of the circulation fan is connected to the second outlet of the primary superheat heater, and the second inlet of the primary superheat heater is connected to the second outlet of the secondary superheat heater through a first air duct switching valve.

[0011] Optionally, the other end of the pressure reducing throttle valve is connected to the first inlet of the molten salt heat exchanger, and the first outlet of the molten salt heat exchanger is connected to the first inlet of the secondary superheat heater through the secondary superheat first control valve; Alternatively, the other end of the pressure reducing throttle valve is connected to the first inlet of the primary superheat heater through a secondary superheat second control valve.

[0012] In another aspect, the application also provides a working method of a steam supply system for cross-temperature-zone heat storage, which adopts the system of the first aspect, and the working method comprises: In response to the valley electricity stage, the hot water generated by the circulating deoxygenated hot water generating unit is stored in the hot water storage tank, the hot molten salt generated by the molten salt electric heater is stored in the molten salt heat storage tank, and the heat generated by the solid heat storage electric heater is stored in the solid heat storage unit; In response to the peak electricity stage and sufficient hot molten salt in the molten salt heat storage tank, the hot water stored in the hot water storage tank is decompressed and vaporized by the decompression throttle valve to obtain steam; the steam enters the molten salt heat exchanger, and the hot molten salt in the molten salt heat storage tank is released into the molten salt heat exchanger, so that the steam is once superheated by the hot molten salt; the once superheated steam enters the secondary superheating heater, and the heat in the solid heat storage unit is released into the secondary superheating heater, so that the once superheated steam is twice superheated by the heat to obtain superheated steam, and the superheated steam is used to heat the steam pipe network; In response to the peak electricity stage and insufficient hot molten salt in the molten salt heat storage tank, the hot water stored in the hot water storage tank is decompressed and vaporized by the decompression throttle valve to obtain steam; the steam enters the once superheating heater, and the steam is once superheated by the heat remaining in the secondary superheating heater at the last moment; the once superheated steam enters the secondary superheating heater, and the heat in the solid heat storage unit is released into the secondary superheating heater, so that the once superheated steam is twice superheated by the heat to obtain superheated steam, and the superheated steam is used to heat the steam pipe network.

[0013] Compared with the prior art, the application has the following beneficial effects: The application stores heat by coupling three media of water, molten salt and solid heat storage material, realizes the integration of hot water heat storage and vaporization, realizes higher-quality and higher-efficiency deoxygenated hot water, and realizes the secondary superheating of steam by molten salt and solid heat storage material to realize high-efficiency heat supply in different temperature zones and heat the external steam pipe network. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 The application is a heat supply system coupling water and molten salt double media in an embodiment, and the structure is shown in the figure. In the figure: 100, thermal deaerator; 110, electrode boiler; 120, hot water storage tank; 130, molten salt cold storage tank; 140, molten salt hot storage tank; 200, water inlet control valve; 210, electrode boiler inlet regulating valve; 220, hot water storage tank inlet regulating valve; 230, first nitrogen pressure control valve; 240, cold salt storage tank outlet valve; 250, second nitrogen pressure control valve; 260, pressure reducing throttle valve; 270, hot salt storage tank outlet valve; 280, second superheat first control valve; 290, Secondary superheating second control valve; 291, first air duct switching valve; 292, second air duct switching valve; 300, desalted water pump; 310, deoxygenated water pump; 320, cold salt pump; 330, molten salt electric heater; 340, hot salt pump; 350, molten salt heat exchanger; 360, secondary superheat heater; 370, primary superheat heater; 380, circulating fan; 390, solid thermal storage unit; 391, solid thermal storage electric heater; 400, nitrogen storage tank; 410, nitrogen compressor. DETAILED DESCRIPTION

[0015] The technical solution of the present invention is described in detail below through the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solution of the present invention, rather than limitations on the technical solution of the present invention. In the absence of conflict, the embodiments of the present invention and the technical features in the embodiments can be combined with each other.

[0016] The term "and / or" simply describes a relationship between related objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, or B exists alone. Additionally, the character " / " generally indicates an "or" relationship between the related objects.

[0017] Example 1

[0018] like Figure 1 As shown, this embodiment introduces a steam supply system for cross-temperature zone heat storage, including a heat storage unit, a steam generation unit, and a nitrogen pressure control unit.

[0019] The heat storage unit includes a hot water heat storage subunit, a molten salt heat storage subunit, and a solid heat storage subunit.

[0020] The hot water heat storage subunit includes a water inlet control valve 200, a deionized water pump 300, a thermal deaerator 100, a deionized water pump 310, an electrode boiler inlet regulating valve 210, an electrode boiler 110, a hot water storage tank inlet regulating valve 220, and a hot water storage tank 120. The thermal deaerator 100 and the electrode boiler 110 constitute a circulating deoxygenated hot water generation unit for producing deoxygenated hot water of higher quality and efficiency to generate deoxygenated steam. The outlet of the thermal deaerator 100 is connected to the inlet of the deaerated water pump 310, the outlet of the deaerated water pump 310 is connected to the inlet of the electrode boiler 110 through the electrode boiler inlet regulating valve 210, the outlet of the electrode boiler 110 is connected to the inlet of the thermal deaerator 100, and the thermal deaerator 100, the deaerated water pump 310, the electrode boiler inlet regulating valve 210, and the electrode boiler 110 are connected in series to form a circulating deaerated hot water loop. The inlet of the circulating deaerated hot water loop is connected to the outlet of the desalted water pump 300, the inlet of the desalted water pump 300 is connected to desalted water through the water inlet control valve 200, the outlet of the circulating deaerated hot water loop is connected to the inlet of the hot water storage tank 120 through the hot water storage tank inlet regulating valve 220, and specifically, the outlet of the desalted water pump 300 is connected to the inlet of the thermal deaerator 100, and the outlet of the deaerated water pump 310 is connected to the first inlet of the hot water storage tank 120 through the hot water storage tank inlet regulating valve 220.

[0021] In a specific embodiment, the water inlet control valve 200 is opened, the desalted water enters the thermal deaerator 100 after being pressurized by the desalted water pump 300, the deaerated hot water at the outlet of the thermal deaerator 100 is divided into two paths after being pressurized by the deaerated water pump 310, one path enters the electrode boiler 110 through the electrode boiler inlet regulating valve 210 to generate steam, and the generated steam returns to the thermal deaerator 100 for thermal deaeration, and the other path enters the hot water storage tank 120 through the hot water storage tank inlet regulating valve 220 for storage.

[0022] The molten salt heat storage subunit includes a molten salt cold storage tank 130, a cold salt pump 320, a cold salt storage tank outlet valve 240, a molten salt electric heater 330, and a molten salt hot storage tank 140. The outlet of the molten salt cold storage tank 130 is connected to the inlet of the cold salt pump 320, the outlet of the cold salt pump 320 is connected to the inlet of the molten salt electric heater 330 through the cold salt storage tank outlet valve 240, and the outlet of the molten salt electric heater 330 is connected to the molten salt hot storage tank 140.

[0023] In a specific embodiment, the cold molten salt in the molten salt cold storage tank 130 is released, pressurized by the cold salt pump 320 and the cold salt storage tank outlet valve 240, and then enters the molten salt electric heater 330 for heating, and after heating, is stored in the molten salt hot storage tank 140.

[0024] The solid heat storage subunit includes a solid heat storage electric heater 391 and a solid heat storage unit 390 connected thereto.

[0025] In a specific embodiment, the solid heat storage electric heater 391 is powered to heat the solid heat storage unit 390 to generate heat.

[0026] The steam generation unit includes a pressure reducing throttle valve 260, a hot salt pump 340, a hot salt storage tank outlet valve 270, a molten salt heat exchanger 350, a secondary superheating first control valve 280, a secondary superheating heater 360, a secondary superheating second control valve 290, a primary superheating heater 370, a first air duct switching valve 291, a second air duct switching valve 292, a secondary superheating heater 360, and a circulating fan 380; Among them, the outlet of the molten salt hot storage tank 140 is connected to the inlet of the hot salt pump 340, the outlet of the hot salt pump 340 is connected to the second inlet of the molten salt heat exchanger 350 through the hot salt storage tank outlet valve 270, and the second outlet of the molten salt heat exchanger 350 is connected back to the inlet of the molten salt cold storage tank 130 to recover the superheated excess molten salt to the molten salt cold storage tank 130 to avoid waste; The inlet of the solid heat storage unit 390 is connected to the outlet of the circulation fan 380, and the outlet of the solid heat storage unit 390 is connected to the second inlet of the secondary superheat heater 360; the inlet of the circulation fan 380 is connected to the second outlet of the secondary superheat heater 360 through the second air duct switching valve 292; or, the inlet of the circulation fan 380 is connected to the second outlet of the primary superheat heater 370, and the second inlet of the primary superheat heater 370 is connected to the second outlet of the secondary superheat heater 360 through the first air duct switching valve 291. The remaining heat after the secondary superheating can be used for the primary superheating at the next moment and then recovered into the solid energy storage material, or it can be directly recovered into the solid heat storage material to avoid heat loss and waste; The first outlet of the hot water storage tank 120 is connected to one end of the pressure reducing throttle valve 260; The other end of the pressure reducing throttle valve 260 is connected to the first inlet of the molten salt heat exchanger 350 , and the first outlet of the molten salt heat exchanger 350 is connected to the first inlet of the secondary superheat heater 360 through the secondary superheat first control valve 280 , and the first outlet of the secondary superheat heater 360 is connected to the steam pipe network; Alternatively, the other end of the pressure reducing throttle valve 260 is connected to the first inlet of the primary superheat heater 370 through the secondary superheat second control valve 290, the first outlet of the primary superheat heater 370 is connected to the first inlet of the secondary superheat heater 360, and the first outlet of the secondary superheat heater 360 is connected to the steam pipe network.

[0027] In a specific embodiment, the hot water stored in the hot water storage tank 120 is released into the pressure reducing throttle valve 260 for decompression and vaporization to form saturated steam. When the amount of hot molten salt in the molten salt heat storage tank 140 is sufficient, the secondary superheating first control valve 280 is opened, and the secondary superheating second control valve 290 is closed. The hot molten salt stored in the molten salt heat storage tank 140 is released and enters the molten salt heat exchanger 350 through the hot salt pump 340 and the hot salt storage tank outlet valve 270. The generated steam is superheated once and then enters the secondary superheat heater 360 for secondary superheating to obtain superheated steam to supply heat to the steam network. In another specific embodiment, the hot water stored in the hot water storage tank 120 is released into the pressure reducing throttle valve 260 for decompression and vaporization to form saturated steam. When the amount of hot molten salt in the molten salt heat storage tank 140 is insufficient, the secondary superheating first control valve 280 is closed, and the secondary superheating second control valve 290 is opened. The saturated steam enters the primary superheating heater 370 for primary superheating, and then enters the secondary superheating heater 360 for secondary superheating to obtain superheated steam to supply heat to the steam pipe network. Among them, the solid heat storage electric heater 391 stops being energized, and the circulating fan 380 starts working to take away the heat in the solid heat storage unit 390. The steam is first superheated by the secondary superheat heater 360, and the remaining heat from the secondary superheat is divided into two paths: when the secondary superheat first control valve 280 is opened and the secondary superheat second control valve 290 is closed, the first air duct switching valve 291 is closed and the second air duct switching valve 292 is opened, and the remaining heat from the secondary superheat is returned to the inlet of the circulating fan 380; when the secondary superheat first control valve 280 is closed and the secondary superheat second control valve 290 is opened, the first air duct switching valve 291 is opened and the second air duct switching valve 292 is closed, and the remaining heat from the secondary superheat is heated by the primary heating superheater 370 to heat the saturated steam, and then returned to the inlet of the circulating fan 380.

[0028] The nitrogen pressure control unit includes a first nitrogen pressure control valve 230, a nitrogen storage tank 400, a nitrogen compressor 410, and a second nitrogen pressure control valve 250. The nitrogen pressure control unit is installed between the second inlet and the second outlet of the hot water storage tank 120; The second outlet of the hot water storage tank 120 is connected to the inlet of the nitrogen storage tank 400 through the first nitrogen pressure control valve 230 , and the outlet of the nitrogen storage tank 400 is connected to the inlet of the nitrogen compressor 410 , and the outlet of the nitrogen compressor 410 is connected to the second inlet of the hot water storage tank 120 through the second nitrogen pressure control valve 250 .

[0029] In a specific embodiment, the nitrogen in the hot water storage tank 120 enters the nitrogen storage tank 400 through the first nitrogen pressure control valve 230. When supplying heat, the nitrogen stored in the nitrogen storage tank 400 is released, compressed by the nitrogen compressor 410, and enters the hot water storage tank 120 through the second nitrogen pressure control valve 250, thereby achieving stable internal pressure of the hot water storage tank 120.

[0030] Therefore, this embodiment couples water, molten salt, and solid thermal storage material to store heat, realizing integrated hot water storage and vaporization, and achieving higher quality and more efficient deoxygenated hot water. The molten salt and solid thermal storage material enable the steam secondary superheating temperature zone to provide heat efficiently to the external steam pipeline network, and also provide a stable pressure environment for hot water storage.

[0031] Example 2

[0032] Based on the embodiment, this embodiment introduces a working method of a steam supply system with cross-temperature zone heat storage, using the system described in Example 1. The working method includes: In response to the valley power phase, the hot water generated by the circulating deoxygenated hot water generating unit is stored in the hot water storage tank 120, the hot molten salt generated by heating the molten salt electric heater 330 is stored in the molten salt heat storage tank 140, and the heat generated by heating the solid thermal storage electric heater 391 is stored in the solid thermal storage unit 390; In response to the peak power phase and the sufficient hot molten salt in the molten salt heat storage tank 140, the hot water stored in the hot water storage tank 120 is decompressed and vaporized through the pressure reducing throttle valve 260 to obtain steam; the steam enters the molten salt heat exchanger 350, and the hot molten salt in the molten salt heat storage tank 140 is released to the molten salt heat exchanger 350, and the steam is superheated once by the hot molten salt; the steam after the primary superheating enters the secondary superheat heater 360, and the heat in the solid thermal storage unit 390 is released to the secondary superheat heater 360, and the steam after the primary superheating is superheated twice by the heat to obtain superheated steam, and the superheated steam is used to supply heat to the steam pipe network; In response to the peak power phase and the insufficient hot molten salt in the molten salt heat storage tank 140, the hot water stored in the hot water storage tank 120 is decompressed and vaporized through the pressure reducing throttle valve 260 to obtain steam; the steam enters the primary superheat heater 370, and is superheated once by the remaining heat from the secondary superheating at the previous moment. The steam after the primary superheating enters the secondary superheat heater 360, and at the same time, the heat in the solid heat storage unit 390 is released to the secondary superheat heater 360, and the steam after the primary superheating is superheated for a secondary time by the heat to obtain superheated steam, and the superheated steam is used to supply heat to the steam network.

[0033] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which are all protected by the present invention.

Claims

1. A steam supply system with cross-temperature heat storage, characterized in that: It includes a hot water storage tank (120), a molten salt heat storage tank (140), a solid heat storage unit (390) and a pressure reducing throttle valve (260); The first inlet of the hot water storage tank (120) is connected to the outlet of the circulating deoxygenated hot water generating unit, and the first outlet of the hot water storage tank (120) is connected to one end of the pressure reducing throttle valve (260); The inlet of the molten salt hot storage tank (140) is connected to the outlet of the molten salt cold storage tank (130) through the molten salt electric heater (330), and the outlet of the molten salt hot storage tank (140) is connected to the second inlet of the molten salt heat exchanger (350); The solid heat storage unit (390) is connected to the solid heat storage electric heater (391), and the outlet of the solid heat storage unit (390) is connected to the second inlet of the secondary superheat heater (360); The other end of the pressure reducing throttle valve (260) is connected to the first inlet of the molten salt heat exchanger (350) or the primary superheat heater (370), the first outlet of the molten salt heat exchanger (350) or the primary superheat heater (370) is connected to the first inlet of the secondary superheat heater (360), and the first outlet of the secondary superheat heater (360) is connected to the steam pipe network.

2. The steam supply system for cross-temperature heat storage according to claim 1, characterized in that: The circulating deoxygenated hot water generating unit comprises a thermal deaerator (100) and an electrode boiler (110); The outlet of the thermal deaerator (100) is connected to the inlet of the deaeration water pump (310), the outlet of the deaeration water pump (310) is connected to the inlet of the electrode boiler (110) through the electrode boiler inlet regulating valve (210), and the outlet of the electrode boiler (110) is connected to the inlet of the thermal deaerator (100). The thermal deaerator (100), the deaeration water pump (310), the electrode boiler inlet regulating valve (210), and the electrode boiler (110) are connected end to end to form a circulating deaeration hot water loop; The inlet of the circulating deoxygenated hot water loop is connected to the outlet of the desalted water pump (300), and the inlet of the desalted water pump (300) is connected to the desalted water via a water inlet control valve (200); The outlet of the circulating deoxygenated hot water loop is connected to the first inlet of the hot water storage tank (120) via a hot water storage tank inlet regulating valve (220).

3. The steam supply system for cross-temperature heat storage according to claim 1, characterized in that: It also includes a nitrogen pressure control unit, which is installed between the second inlet and the second outlet of the hot water storage tank (120).

4. The steam supply system for cross-temperature heat storage according to claim 3, characterized in that: The nitrogen pressure control unit comprises a nitrogen storage tank (400) and a nitrogen compressor (410); The second outlet of the hot water storage tank (120) is connected to the inlet of the nitrogen storage tank (400) via a first nitrogen pressure-controlling valve (230), the outlet of the nitrogen storage tank (400) is connected to the inlet of the nitrogen compressor (410), and the outlet of the nitrogen compressor (410) is connected to the second inlet of the hot water storage tank (120) via a second nitrogen pressure-controlling valve (250).

5. The steam supply system for cross-temperature heat storage according to claim 1, characterized in that: The molten salt electric heater (330) is connected to the outlet of the cold salt pump (320) via the cold salt storage tank outlet valve (240), and the inlet of the cold salt pump (320) is connected to the outlet of the molten salt cold storage tank (130); The outlet of the molten salt hot storage tank (140) is connected to the inlet of the hot salt pump (340), the outlet of the hot salt pump (340) is connected to the second inlet of the molten salt heat exchanger (350) through the hot salt storage tank outlet valve (270), and the second outlet of the molten salt heat exchanger (350) is connected to the inlet of the molten salt cold storage tank (130).

6. The steam supply system for cross-temperature heat storage according to claim 1, characterized in that: The inlet of the solid heat storage unit (390) is connected to the outlet of the circulation fan (380); The inlet of the circulating fan (380) is connected to the second outlet of the secondary superheat heater (360) via a second air duct switching valve (292); Alternatively, the inlet of the circulating fan (380) is connected to the second outlet of the primary superheat heater (370), and the second inlet of the primary superheat heater (370) is connected to the second outlet of the secondary superheat heater (360) via the first air duct switching valve (291).

7. The steam supply system for cross-temperature heat storage according to claim 1, characterized in that: The other end of the pressure reducing throttle valve (260) is connected to the first inlet of the molten salt heat exchanger (350), and the first outlet of the molten salt heat exchanger (350) is connected to the first inlet of the secondary superheat heater (360) via the secondary superheat first control valve (280); Alternatively, the other end of the pressure reducing throttle valve (260) is connected to the first inlet of the primary superheat heater (370) via the secondary superheat second control valve (290).

8. A method for operating a steam supply system with cross-temperature heat storage, characterized in that: Using the system according to any one of claims 1 to 7, the working method includes: In response to the valley power phase, hot water generated by the circulating deoxygenated hot water generating unit is stored in the hot water storage tank (120), hot molten salt generated by heating the molten salt electric heater (330) is stored in the molten salt heat storage tank (140), and heat generated by heating the solid thermal storage electric heater (391) is stored in the solid thermal storage unit (390); In response to the peak power phase and the sufficient hot molten salt in the molten salt heat storage tank (140), the hot water stored in the hot water storage tank (120) is decompressed and vaporized through the pressure reducing throttle valve (260) to obtain steam; the steam enters the molten salt heat exchanger (350), and at the same time, the hot molten salt in the molten salt heat storage tank (140) is released to the molten salt heat exchanger (350), and the steam is superheated once by the hot molten salt; the steam after the primary superheating enters the secondary superheating heater (360), and at the same time, the heat in the solid heat storage unit (390) is released to the secondary superheating heater (360), and the steam after the primary superheating is secondary superheated by the heat to obtain superheated steam, and the superheated steam is used to supply heat to the steam pipe network; In response to the peak power phase and the insufficient hot molten salt in the molten salt heat storage tank (140), the hot water stored in the hot water storage tank (120) is decompressed and vaporized through the pressure reducing throttle valve (260) to obtain steam; the steam enters the primary superheat heater (370), and the steam is superheated once by the residual heat from the secondary superheating at the previous moment, and the steam after the primary superheating enters the secondary superheat heater (360), and at the same time, the heat in the solid heat storage unit (390) is released to the secondary superheat heater (360), and the steam after the primary superheating is superheated twice by the heat to obtain superheated steam, and the steam pipe network is heated by the superheated steam.

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