Double-heat-storage electric heating cascade temperature raising steam supply system and operation method

Abstract

The invention discloses a double-heat-storage electric heating gradient temperature raising steam supply system and an operation method, belongs to the technical field of industrial steam supply, focuses on a thermoelectricity decoupling scene of'off-peak electricity energy storage-peak steam supply ', and is suitable for industries needing industrial steam, such as chemical engineering, pharmacy, food processing and the like. In order to solve the problems that an existing system is large in occupied area, storage and supply separation is achieved, steam pressure / superheat degree adaptability is poor, and operation cost is high, the system is designed according to the working conditions that steam supply pressure is smaller than or equal to Po / larger than Po (Po is a steam supply pressure threshold value, preferably 1.6 MPa.g, and 1.2-2.0 MPa.g can be adjusted) when Po is smaller than or equal to Po, the system comprises five modules of water supply, electrode steam generation, steam direct supply adjustment, spherical tank heat storage and release and steam temperature rising and heat storage; and when Po is greater than Po, a steam compression module is additionally arranged to realize high-pressure steam supply. The system supports four types of core operation modes such as storage and supply at the same time, stability of steam parameters is guaranteed, the energy utilization efficiency is improved, the cost is reduced, power grid peak regulation and industrial energy conservation and carbon reduction are assisted through cooperative gradient temperature rising of latent heat of the spherical tank and sensible heat of the temperature rising module, and the industrial steam use requirement is met.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of industrial steam preparation and supply, and specifically relates to the cross field of thermal energy engineering, power systems, and automation and industrial energy use, with a core focus on the heat and electricity decoupling application scenario of "low valley electricity energy storage-high peak steam supply", and being suitable for the chemical, pharmaceutical, food processing and other industries that have stable supply requirements for industrial steam (including low pressure ≤1.6 MPa.g and high pressure >1.6 MPa.g). The present application aims to solve the problems of industrial steam peak valley load matching, steam parameter flexible adaptation and energy efficient utilization through double heat storage (spherical tank heat storage + molten salt / solid heat storage) and electric heating step-by-step temperature raising technology. BACKGROUND

[0002] Under the promotion of the "double carbon" goal, the demand for "low valley electricity energy storage-high peak steam supply" in the industrial field is increasingly urgent. As a key equipment for connecting electric energy and thermal energy, the heat storage and steam supply system has been widely used in the chemical, pharmaceutical, food processing and other industries. However, the existing technical solutions cannot fully consider efficiency, flexibility and economy, which restricts its large-scale popularization and application.

[0003] The traditional single solid heat storage and steam supply system has obvious shortcomings: first, the overall land occupation is large, and the demand for site resources is high; second, the structure design and manufacturing of the supporting large-capacity steam generation system are complex, and the starting response speed is slow, which cannot quickly match the sudden and immediate steam supply demand in industrial production; third, the comprehensive cost of equipment purchase, construction installation and later operation and maintenance is high.

[0004] The single molten salt heat storage and steam supply system also has room for improvement: first, molten salt has low-temperature crystallization characteristics, and a large amount of molten salt needs to be maintained at a high temperature to avoid crystallization, which not only increases additional energy consumption, but also increases the difficulty of operation and control; second, the structure design and manufacturing of the supporting large-capacity steam generation system are complex, and the starting response is slow, which makes it difficult to quickly adapt to the sudden and immediate steam supply demand of industrial production; third, the comprehensive cost of equipment purchase, construction installation and later operation and maintenance is high; fourth, in the process of large-scale electric heating of molten salt and molten salt heating of water / steam, the heat transfer and heat exchange links are complex, which makes the system operation regulation and control difficult.

[0005] Although the single electrode steam boiler-spherical tank heat storage and steam supply system has the advantages of relatively simple structure and low initial investment, it still has shortcomings: it can only output low-pressure saturated steam, and cannot meet the needs of the chemical, pharmaceutical and other industries that have specific requirements for steam superheat degree; if an additional steam electric heater is configured, when the user has a high demand for steam superheat degree, the steam supply during the peak period of the power grid will significantly increase the electric energy consumption, and thus increase the operation cost.

[0006] In the field of dual-medium energy storage steam supply, CN119022700A patent (Invention name: A dual-medium energy storage steam supply system and operation method) adopts a "energy storage-steam supply time-sharing operation" mode: during the off-peak period of the power grid (energy storage stage), the molten salt and high-pressure water are heated by electric heating devices to realize energy storage; during the peak period of the power grid or the user steam demand period (steam supply stage), the electric heating needs to be stopped, and only the heat storage medium is relied on for heat exchange to realize steam supply, which cannot realize "energy storage and supply simultaneously". On the one hand, when there is a temporary incremental steam demand of the user, if it is in the energy storage stage, the heat storage needs to be interrupted to supply steam, which lacks flexibility in system operation; on the other hand, the heat storage and steam supply processes are completely separated, which loses the opportunity of energy cascade utilization brought by "energy storage and supply simultaneously", and affects the overall energy utilization efficiency.

[0007] In summary, the existing system still has obvious optimization space in terms of structural design (land occupation scale, system complexity), operation mode (synchronization of storage and supply, flexibility of working condition adaptation), function adaptation (diversity of steam parameters), and economy (initial investment, operation energy consumption, and full life cycle cost), and a new energy storage steam supply system is needed to realize the core target of "small land occupation, fast response, wide parameter range, synchronization of storage and supply, and low full life cycle cost", so as to improve the energy utilization efficiency and meet the diversified energy demand in the industrial field. SUMMARY

[0008] In view of the problems of large land occupation, slow start response, inability to realize "energy storage and supply simultaneously", poor adaptability of steam parameters (pressure / overheating degree), high operation cost, and low energy utilization efficiency of the existing industrial heat storage steam supply system (single solid / molten salt heat storage system, single electrode steam boiler-sphere tank system, dual-medium time-sharing storage and supply system, etc.), the present application aims to provide a dual-heat storage electric heating cascade temperature-raising steam supply system and operation method, and the specific purposes include: 1. Realize thermal-electric decoupling of "off-peak electricity heat storage-high peak heat release", meet the peak-valley load matching demand of industrial steam, and reduce the dependence on electricity during the peak period of the power grid; 2. Through the dual-heat storage cooperation and cascade temperature-raising of "sphere tank heat storage and heat release module + steam temperature-raising and heat storage module (molten salt / solid optional)", solve the problem of insufficient steam overheating degree of single heat storage system, and adapt to the diversified demand of steam parameters in the chemical and pharmaceutical industries; 3. Support the "energy storage and supply simultaneously" operation mode, avoid the defect of "separation of heat storage and steam supply" of the existing dual-medium system, improve the flexibility of system operation, and cope with the temporary incremental steam demand of industry; 4. Consider both low-pressure (≤Po, preferably 1.6 MPa.g) and high-pressure (>Po) steam supply, realize flexible and adjustable steam supply pressure through modular expansion (series connection of steam compression modules), and expand the application scenarios; 5. Optimize system structure and operation logic, reduce the whole life cycle cost of equipment purchase, installation and operation, and ensure long-term safe and stable operation of the system through deoxidation, safety valve and other designs.

[0009] To achieve the above-mentioned purpose, the application provides a double-thermal-storage electric heating step-by-step temperature-raising steam supply system, when the steam supply pressure is ≤Po (wherein Po is a steam supply pressure threshold, preferably 1.6 MPa.g, and can be adjusted to 1.2 MPa.g~2.0 MPa.g according to actual requirements), the system comprises a make-up water module, an electrode steam generation module, a steam direct supply adjustment module, a spherical tank heat storage and heat release module, and a steam temperature-raising heat storage module; when the steam supply pressure is >Po, the system adds a steam compression module based on the above-mentioned five modules.

[0010] The make-up water module comprises a buffer tank, a spherical tank water supply pump, a deaerator water supply pump, a deaerator, and a deaeration steam pressure reducing valve; The electrode steam generation module comprises a boiler feed water pump, an electrode steam boiler, a high-pressure steam cylinder, and a high-voltage electrode; The steam direct supply adjustment module comprises a low-pressure steam cylinder, a steam electric heater, a boiler direct supply pressure reducing valve, a direct supply electric gate valve, and a storage supply electric gate valve; The spherical tank heat storage and heat release module comprises a spherical tank and a flash pressure reducing valve; The steam temperature-raising heat storage module is a core module for realizing the functions of step-by-step temperature-raising and heat storage of the system, and can selectively adopt the following two forms: When the steam temperature-raising heat storage module adopts a molten salt heat storage form, it comprises a low-temperature molten salt tank, a low-temperature molten salt pump, a molten salt electric heater, a high-temperature molten salt tank, a high-temperature molten salt pump, and a molten salt-steam heat exchanger; When the steam temperature-raising heat storage module adopts a solid heat storage form, it comprises a solid electric heat storage device, a gas-steam heat exchanger, and a high-temperature circulating fan; The steam compression module comprises a compressor inlet temperature reducing device, a steam compressor, and a compressor outlet temperature reducing device; When the steam supply pressure of the double-thermal-storage electric heating step-by-step temperature-raising steam supply system is ≤Po (wherein Po is a steam supply pressure threshold, preferably 1.6 MPa.g, and can be adjusted to 1.2 MPa.g~2.0 MPa.g according to user requirements), the system structure is as follows: The first water supplement inlet of the buffer tank is connected to the chemical desalination water system through a pipeline; the second water supplement outlet of the buffer tank is connected to the water supplement inlet of the spherical tank water supplement pump through a pipeline; the water supplement outlet of the spherical tank water supplement pump is connected to the first water supplement inlet of the spherical tank through a pipeline; the third water supplement outlet of the buffer tank is connected to the water supplement inlet of the deaerator water supplement pump through a pipeline; the water supplement outlet of the deaerator water supplement pump is connected to the first water supplement inlet of the deaerator through a pipeline; the second steam inlet of the deaerator is connected to the fifth steam outlet of the low-pressure cylinder through a pipeline, and a deaerating steam pressure reducing valve is arranged on the pipeline; the third feed water outlet of the deaerator is connected to the feed water inlet of the boiler feed water pump through a pipeline; The feed water outlet of the boiler feed water pump is connected to the feed water inlet of the electrode steam boiler through a pipeline; the electrode steam boiler is provided with a high-voltage electrode, and the high-voltage electrode is connected to a high-voltage power supply through an electric circuit; the steam outlet of the electrode steam boiler is connected to the first steam inlet of the high-pressure cylinder through a pipeline; the second steam outlet of the high-pressure cylinder is connected to the second steam inlet of the low-pressure cylinder through a pipeline, and a boiler direct supply pressure reducing valve is arranged on the pipeline; the third steam outlet of the high-pressure cylinder is connected to the second steam inlet of the spherical tank through a pipeline; The third steam outlet of the spherical tank is connected to the first steam inlet of the low-pressure cylinder through a pipeline, and a flash pressure reducing valve is arranged on the pipeline; The third steam outlet of the low-pressure cylinder is connected to the steam inlet of the steam electric heater through a pipeline, and a direct supply electric gate valve is arranged on the pipeline; the steam outlet of the steam electric heater is connected to an industrial steam (steam supply pressure ≤Po) pipeline to provide industrial steam outside, and the power input end of the steam electric heater is connected to a high-voltage power supply through an electric circuit; the fourth steam outlet of the low-pressure cylinder is connected to the steam inlet of the steam temperature-raising heat storage module through a pipeline, and a storage supply electric gate valve is arranged on the pipeline; The steam outlet of the steam temperature-raising heat storage module is connected to an industrial steam (steam supply pressure ≤Po) pipeline to provide industrial steam outside.

[0011] When the steam temperature-raising heat storage module adopts the molten salt heat storage form, the steam inlet of the steam temperature-raising heat storage module is the first steam inlet of the molten salt-steam heat exchanger, and the steam outlet of the steam temperature-raising heat storage module is the second steam outlet of the molten salt-steam heat exchanger; the molten salt outlet of the low-temperature molten salt tank is connected to the molten salt inlet of the low-temperature molten salt pump through a pipeline; the molten salt outlet of the low-temperature molten salt pump is connected to the molten salt inlet of the molten salt electric heater through a pipeline; the power input end of the molten salt electric heater is connected to a high-voltage power supply through an electric circuit; the molten salt outlet of the molten salt electric heater is connected to the molten salt inlet of the high-temperature molten salt tank through a pipeline; the molten salt outlet of the high-temperature molten salt tank is connected to the molten salt inlet of the high-temperature molten salt pump through a pipeline; the molten salt outlet of the high-temperature molten salt pump is connected to the third molten salt inlet of the molten salt-steam heat exchanger through a pipeline; and the fourth molten salt outlet of the molten salt-steam heat exchanger is connected to the molten salt inlet of the low-temperature molten salt tank through a pipeline.

[0012] When the steam temperature-raising heat storage module adopts the solid heat storage form, the steam inlet of the steam temperature-raising heat storage module is the first steam inlet of the gas-steam heat exchanger, and the steam outlet of the steam temperature-raising heat storage module is the second steam outlet of the gas-steam heat exchanger; the gas outlet of the solid electric heat storage device is connected to the third gas inlet of the gas-steam heat exchanger through an air duct; the fourth gas outlet of the gas-steam heat exchanger is connected to the gas inlet of the high-temperature circulating fan through an air duct; and the gas outlet of the high-temperature circulating fan is connected to the gas inlet of the solid electric heat storage device through an air duct.

[0013] The high-voltage power supply of the steam temperature-raising heat storage module is connected to the high-voltage power supply of the high-voltage electrode of the electrode steam boiler at the same connection position, and is connected to a high-voltage power supply through an electric circuit.

[0014] In the double-heat-storage electric heating step temperature-raising steam supply system, safety valves are arranged for key devices such as the deaerator, the electrode steam boiler, the high-pressure steam cylinder, the low-pressure steam cylinder, and the spherical tank, and when the pressure rises to the set pressure, the safety valves are automatically opened to release pressure, which can effectively avoid damage to the devices or safety accidents caused by overpressure.

[0015] As an optional solution, when the steam temperature-raising heat storage module adopts the molten salt heat storage form, the selected types of molten salt include binary molten salt and ternary molten salt.

[0016] As an optional solution, the heat storage material of the solid electric heat storage device can be selected according to the heat storage temperature, the specific heat capacity, the heat conduction performance, and the economy, and specifically, the following materials can be selected: magnesia brick, ceramic material, alloy material, and modified graphite block.

[0017] When the steam supply pressure of the double-heat-storage electric heating step temperature-raising steam supply system is greater than Po, the system structure is as follows: A dual-storage thermal electric heating cascade steam supply system with a steam supply pressure > Po adds a series-connected steam compression module at the end of the process compared to a system with a steam supply pressure ≤ Po (the equipment and piping within the module are adapted to pressure conditions > Po). The structure and connection relationships of the first five modules are the same and will not be described again. The differences and additions are as follows: The steam outlet of the steam electric heater and the steam outlet of the steam heating and heat storage module are connected through a pipeline to the steam inlet of the compressor inlet desuperheating device. The steam outlet of the compressor inlet desuperheating device is connected to the steam inlet of the steam compressor through a pipeline. The steam compressor is equipped with a variable frequency speed control device, which can stabilize the outlet steam pressure through variable frequency speed control technology. At the same time, in order to cope with surge conditions, the steam compressor can be equipped with an anti-surge backflow pipeline and an anti-surge backflow valve. Through backflow regulation, the operating state of the equipment can be further stabilized, ensuring the safe and stable operation of the system. The steam outlet of the steam compressor is connected to the steam inlet of the compressor outlet desuperheating device through a pipeline. The steam outlet of the compressor outlet desuperheating device is connected to an industrial steam (steam supply pressure > Po) pipeline to supply industrial steam.

[0018] In this embodiment, each device is configured as a single unit. As an improvement to the technical solution, the dual thermal storage electric heating cascade temperature boosting and steam supply system can be flexibly configured according to the actual production, storage and supply scale, equipment capacity and site conditions. Among them, the buffer water tank, spherical tank water supply pump, deaerator water supply pump, boiler feed water pump, electrode steam boiler, steam electric heater, spherical tank, compressor inlet desuperheating device, steam compressor, compressor outlet desuperheating device, etc. can be configured in parallel with multiple units according to relevant standards and specifications, usage requirements and backup needs.

[0019] The beneficial effects of this invention are: 1. High operational flexibility and adaptability to working conditions It supports four core operating modes: direct supply from electrode steam boiler, dual-storage electric heating and heat storage, dual-storage heat release steam supply, and single-storage heat release steam supply. It can flexibly switch according to industrial steam load and power period characteristics (off-peak / peak). It can also generate auxiliary modes such as joint and emergency backup, and can cope with diverse working conditions such as instantaneous steam supply and temporary incremental steam supply. The steam temperature enhancement and heat storage module provides two optional heat storage forms: molten salt and solid. It can be installed according to the heat storage temperature, site conditions, and economic requirements to adapt to different application scenarios. The steam supply pressure covers low pressure (≤Po, Po is preferred to be 1.6MPa.g) and high pressure (>Po). High pressure expansion can be achieved by simply connecting the steam compression module in series without reconstructing the basic system, which can adapt to the steam pressure requirements of different industries.

[0020] 2. High energy efficiency and low operating costs The system enables "simultaneous storage and supply," allowing for direct steam supply to industrial applications during off-peak hours while storing thermal energy. This avoids the energy waste associated with existing time-of-use storage and supply systems that cannot supply steam during thermal storage, thus improving the efficiency of energy cascade utilization. Thermal storage during off-peak hours reduces the cost of electricity during peak hours due to high electricity prices. Combined with the synergistic heat release from dual thermal storage (latent heat provided by the spherical tank + superheated sensible heat provided by the temperature-raising module), it reduces the energy consumption of additional electric heating equipment, significantly lowering operating costs. Core equipment (such as buffer tanks, pump sets, electrode steam boilers, spherical tanks, and steam compressors) supports multiple units in parallel configuration, which can be flexibly adjusted according to the scale of production, storage, and supply, avoiding energy efficiency losses caused by "oversized engines operating on small scales."

[0021] 3. Controllable steam parameters to meet diverse steam demand. By adopting the design of "steam electric heater + dual heat storage stepped temperature increase", the problem of insufficient steam superheat in the existing system is solved, and superheated steam that meets the requirements of chemical, pharmaceutical and other industries can be stably output. The steam supply pressure threshold Po (preferably 1.6MPa.g) can be adjusted to 1.2MPa.g~2.0MPa.g according to user needs. In high pressure scenarios, the outlet pressure is controlled by frequency conversion speed regulation of steam compressor to ensure stable steam parameters.

[0022] 4. High system security and reliability Key equipment such as deaerators, electrode steam boilers, high / low pressure steam distribution cylinders, and spherical tanks are all equipped with safety valves that automatically release pressure in case of overpressure, preventing equipment damage or safety accidents. The deaerator uses low-pressure steam for heating and deoxygenation, ensuring feedwater quality, reducing equipment scaling and corrosion, and extending service life. The steam compressor is equipped with a frequency converter and anti-surge backflow pipelines / valve to ensure safe high-pressure steam supply.

[0023] Excellent economic performance and low total life cycle cost The system employs a dual thermal storage design, combining a spherical tank thermal storage and release module with a steam-heat-raising thermal storage module (selectable between molten salt and solid thermal storage), reducing equipment purchase and construction costs. The synergistic effect of the dual thermal storage avoids reliance on high-cost thermal storage materials (such as molten salt), reducing usage and lowering long-term operation and maintenance costs. Through off-peak electricity thermal storage and efficient energy utilization, operating electricity costs are significantly reduced. Combined with the long-life design of the equipment, its overall life-cycle economics are superior to existing single molten salt / solid thermal storage systems or time-of-use thermal storage systems.

[0024] 6. Contributing to the "dual carbon" target, with significant energy and environmental benefits. By achieving thermal-electric decoupling through "off-peak energy storage and peak heat release," the reliance on electricity during peak hours on the power grid is reduced, thus lowering carbon emissions. The system's energy utilization efficiency is improved, avoiding energy waste caused by the separation of heat storage and steam supply, which meets the development needs of energy conservation and carbon reduction in the industrial sector. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0026] In this invention, P0 is the steam supply pressure threshold, preferably 1.6 MPa.g. In practical applications, it can be adjusted to a reasonable range such as 1.2 MPa.g to 2.0 MPa.g according to the user's steam supply needs.

[0027] Figure 1 This is a schematic diagram of the overall structure of a dual-storage thermoelectric heating cascade temperature-raising and steam supply system (steam supply pressure ≤ Po) according to the present invention; Figure 2 This is a schematic diagram of the structure of the steam heating and heat storage module in this invention when a molten salt heat storage module is used; Figure 3 This is a schematic diagram of the structure of the steam heating and heat storage module in this invention when a solid heat storage module is used; Figure 4 This is a schematic diagram of the overall structure of a dual-storage thermoelectric heating cascade temperature-raising and steam supply system (steam supply pressure > Po) according to the present invention; It should be noted that, Figure 2 The molten salt thermal storage module shown is Figure 3 The solid thermal storage module shown represents two optional assembly schemes for the steam-heating thermal storage module. The two can not be set up simultaneously, and one can be selected for assembly according to the actual thermal storage requirements and application scenarios.

[0028] Figure label: 1-Makeup water module; 1.1-Buffer water tank; 1.2-Spherical tank makeup water pump; 1.3-Deaerator makeup water pump; 1.4-Deaerator; 1.5-Deaerator steam pressure reducing valve; 2-Electrode steam generating module; 2.1-Boiler feed water pump; 2.2-Electrode steam boiler; 2.3-High-pressure steam distributor; 2.4-High-pressure electrode; 3-Steam direct supply regulating module; 3.1-Low-pressure steam distributor; 3.2-Steam electric heater; 3.3-Boiler direct supply pressure reducing valve; 3.4-Direct power electric gate valve; 3.5-Storage power electric gate valve; 4-Spherical tank heat storage and release module; 4.1-Spherical tank; 4.2-Flash pressure reducing valve; 5-Steam temperature rise and heat storage module; Molten salt heat storage module (corresponding to...) Figure 2 ): 5.1-1-Low-temperature molten salt tank; 5.1-2-Low-temperature molten salt pump; 5.1-3-Molten salt electric heater; 5.1-4-High-temperature molten salt tank; 5.1-5-High-temperature molten salt pump; 5.1-6-Molten salt-steam heat exchanger; Solid thermal storage module (corresponding) Figure 3): 5.2-1-Solid-state electric thermal storage device; 5.2-2-Gas-steam heat exchanger; 5.2-3-High-temperature circulating fan; 6-Steam compression module; 6.1-Compressor inlet desuperheating device; 6.2-Steam compressor; 6.3-Compressor outlet desuperheating device. Detailed Implementation

[0029] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0030] Unless otherwise expressly specified and limited, the terms "first, second, third, fourth or fifth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; the terms "connected" or "linked" should be interpreted broadly, for example: they can be fixed connections, detachable connections or integral connections, they can be mechanical connections, electrical connections or direct connections, they can also be indirect connections through an intermediate medium, or they can be the internal connection of two components.

[0031] like Figure 1 As shown, the present invention provides a dual thermal storage electric heating cascade temperature rise and steam supply system (steam supply pressure ≤ Po, where Po is the steam supply pressure threshold, preferably 1.6 MPa.g, which can be adjusted according to actual needs), including a water supply module 1, an electrode steam generation module 2, a steam direct supply regulation module 3, a spherical tank thermal storage and heat release module 4, and a steam temperature rise and heat storage module 5. like Figure 4 As shown, the present invention provides a dual thermal storage electric heating cascade temperature rise and steam supply system (steam supply pressure > Po), which includes a water supply module 1, an electrode steam generation module 2, a steam direct supply regulation module 3, a spherical tank thermal storage and heat release module 4, a steam temperature rise and heat storage module 5, and a steam compression module 6. The water supply module 1 includes a buffer tank 1.1, a spherical tank water supply pump 1.2, a deaerator water supply pump 1.3, a deaerator 1.4, and a deaerator steam pressure reducing valve 1.5; The electrode steam generating module 2 includes a boiler feedwater pump 2.1, an electrode steam boiler 2.2, a high-pressure steam distributor 2.3, and a high-pressure electrode 2.4; The steam direct supply regulating module 3 includes a low-pressure steam distribution cylinder 3.1, a steam electric heater 3.2, a boiler direct supply pressure reducing valve 3.3, a direct-supply electric gate valve 3.4, and a storage-supply electric gate valve 3.5; The spherical tank heat storage and release module 4 includes a spherical tank 4.1 and a flash pressure reducing valve 4.2; The steam heating and heat storage module 5 is the core module of the system to realize the cascade heating and heat storage functions, and it can be selectively adopted in the following two forms: When the steam heating and heat storage module 5 adopts the molten salt heat storage form (such as...) Figure 2As shown), it includes a cryogenic molten salt tank 5.1-1, a cryogenic molten salt pump 5.1-2, a molten salt electric heater 5.1-3, a high-temperature molten salt tank 5.1-4, a high-temperature molten salt pump 5.1-5, and a molten salt-steam heat exchanger 5.1-6; When the steam heating and heat storage module 5 adopts a solid heat storage form (such as...) Figure 3 As shown), it includes a solid-state electric thermal energy storage device 5.2-1, a gas-vapor heat exchanger 5.2-2, and a high-temperature circulating fan 5.2-3; The steam compression module 6 includes a compressor inlet desuperheating device 6.1, a steam compressor 6.2, and a compressor outlet desuperheating device 6.3; The following describes a dual thermal storage electric heating cascade temperature-raising steam supply system (e.g., with a steam supply pressure ≤ Po (where Po is the steam supply pressure threshold, preferably 1.6 MPa.g, which can be adjusted according to actual needs) for steam supply pressure ≤ Po of the present invention. Figure 1 (As shown), a detailed explanation of the connection relationships, working logic, and optional technical solutions of each module and component is provided: The first water inlet of the buffer tank 1.1 is connected to the chemical demineralized water system via a pipeline; the second water outlet of the buffer tank 1.1 is connected to the water inlet of the spherical tank water pump 1.2 via a pipeline; the water outlet of the spherical tank water pump 1.2 is connected to the first water inlet of the spherical tank 4.1 via a pipeline; the third water outlet of the buffer tank 1.1 is connected to the water inlet of the deaerator water pump 1.3 via a pipeline; the water outlet of the deaerator water pump 1.3 is connected to the first water inlet of the deaerator 1.4 via a pipeline; the second steam inlet of the deaerator 1.4 is connected to the fifth steam outlet of the low-pressure steam separator 3.1 via a pipeline, and the pipeline is equipped with a deaeration steam pressure reducing valve 1.5; the third feedwater outlet of the deaerator 1.4 is connected to the feedwater inlet of the boiler feedwater pump 2.1 via a pipeline. The feedwater outlet of the boiler feedwater pump 2.1 is connected to the feedwater inlet of the electrode steam boiler 2.2 via a pipeline; the electrode steam boiler 2.2 is equipped with a high-voltage electrode 2.4, which is connected to a high-voltage power supply via an electrical circuit; the steam outlet of the electrode steam boiler 2.2 is connected to the first steam inlet of the high-pressure steam distributor 2.3 via a pipeline; the second steam outlet of the high-pressure steam distributor 2.3 is connected to the second steam inlet of the low-pressure steam distributor 3.1 via a pipeline, and a boiler direct supply pressure reducing valve 3.3 is installed on the pipeline; the third steam outlet of the high-pressure steam distributor 2.3 is connected to the second steam inlet of the spherical tank 4.1 via a pipeline. The third steam outlet of the spherical tank 4.1 is connected to the first steam inlet of the low-pressure steam distribution cylinder 3.1 via a pipeline, and the pipeline is equipped with a flash pressure reducing valve 4.2; The third steam outlet of the low-pressure steam distributor 3.1 is connected to the steam inlet of the steam electric heater 3.2 via a pipeline, and a direct-acting electric gate valve 3.4 is installed on the pipeline; the steam outlet of the steam electric heater 3.2 is connected to an industrial steam (steam supply pressure ≤ Po) pipeline to supply industrial steam externally, and the power input terminal of the steam electric heater 3.2 is connected to a high-voltage power supply via an electrical circuit; the fourth steam outlet of the low-pressure steam distributor 3.1 is connected to the steam inlet of the steam heating and heat storage module 5 via a pipeline, and a storage electric gate valve 3.5 is installed on the pipeline; The steam outlet of the steam heating and heat storage module 5 is connected to an industrial steam (steam supply pressure ≤ Po) pipeline to supply industrial steam to the outside.

[0032] When the steam heating and heat storage module 5 adopts the molten salt heat storage form (such as...) Figure 2 As shown in the diagram, the steam inlet of the steam heating and heat storage module 5 is the first steam inlet of the molten salt-steam heat exchanger 5.1-6, and the steam outlet of the steam heating and heat storage module 5 is the second steam outlet of the molten salt-steam heat exchanger 5.1-6; the molten salt outlet of the low-temperature molten salt tank 5.1-1 is connected to the molten salt inlet of the low-temperature molten salt pump 5.1-2 via a pipeline; the molten salt outlet of the low-temperature molten salt pump 5.1-2 is connected to the molten salt inlet of the molten salt electric heater 5.1-3 via a pipeline; the power input terminal of the molten salt electric heater 5.1-3... The molten salt outlet of the molten salt electric heater 5.1-3 is connected to the molten salt inlet of the high-temperature molten salt tank 5.1-4 via a pipeline; the molten salt outlet of the high-temperature molten salt tank 5.1-4 is connected to the molten salt inlet of the high-temperature molten salt pump 5.1-5 via a pipeline; the molten salt outlet of the high-temperature molten salt pump 5.1-5 is connected to the third molten salt inlet of the molten salt-steam heat exchanger 5.1-6 via a pipeline; and the fourth molten salt outlet of the molten salt-steam heat exchanger 5.1-6 is connected to the molten salt inlet of the low-temperature molten salt tank 5.1-1 via a pipeline.

[0033] When the steam heating and heat storage module 5 adopts a solid heat storage form (such as...) Figure 3 As shown in the diagram, the steam inlet of the steam heating and heat storage module 5 is the first steam inlet of the gas-steam heat exchanger 5.2-2, and the steam outlet of the steam heating and heat storage module 5 is the second steam outlet of the gas-steam heat exchanger 5.2-2; the gas outlet of the solid electric heat storage device 5.2-1 is connected to the third gas inlet of the gas-steam heat exchanger 5.2-2 through a duct; the fourth gas outlet of the gas-steam heat exchanger 5.2-2 is connected to the gas inlet of the high-temperature circulating fan 5.2-3 through a duct; and the gas outlet of the high-temperature circulating fan 5.2-3 is connected to the gas inlet of the solid electric heat storage device 5.2-1 through a duct.

[0034] The high-voltage power supply of the steam heating and heat storage module 5 is connected to the high-voltage power supply of the high-voltage electrode 2.4 of the electrode steam boiler 2.2 at the same location, and is connected to the high-voltage power supply through an electrical circuit.

[0035] In the dual-storage thermal electric heating cascade temperature rise and steam supply system, key equipment such as the deaerator 1.4, electrode steam boiler 2.2, high-pressure steam distributor 2.3, low-pressure steam distributor 3.1, and spherical tank 4.1 are all equipped with safety valves. When the pressure rises to the set pressure, the valves automatically open to release pressure, which can effectively prevent equipment damage or safety accidents caused by overpressure.

[0036] As an optional solution, when the steam heating and heat storage module 5 adopts the form of molten salt heat storage, the selected molten salt type includes binary molten salt and ternary molten salt.

[0037] As an optional option, the heat storage material of the solid electric heat storage device 5.2-1 can be selected according to the heat storage temperature, specific heat capacity, thermal conductivity and economy. Specifically, it can be selected from: magnesium oxide bricks, ceramic materials, alloy materials, modified graphite blocks, etc.

[0038] The following pertains to the dual-storage thermal electric heating cascade temperature-raising steam supply system of the present invention, where the steam supply pressure is > Po (e.g., Figure 4 (As shown), a detailed explanation of the connection relationships, working logic, and optional technical solutions of each module and component is provided: The dual-storage electric heating cascade steam supply system with a steam supply pressure > Po adds a series-connected steam compression module 6 at the end of the process compared to the system with a steam supply pressure ≤ Po (the equipment and piping within the module are all adapted to pressure conditions > Po). The structure and connection relationship of the first 5 modules are the same and will not be described again. The differences and additions are as follows: The steam outlet of the steam electric heater 3.2 and the steam outlet of the steam heating and heat storage module 5 are connected through a pipeline to the steam inlet of the compressor inlet desuperheating device 6.1. The steam outlet of the compressor inlet desuperheating device 6.1 is connected through a pipeline to the steam inlet of the steam compressor 6.2. The steam compressor 6.2 is equipped with a variable frequency speed control device, which can stabilize the outlet steam pressure through variable frequency speed control technology. At the same time, in order to cope with surge conditions, the steam compressor 6.2 can be equipped with an anti-surge backflow pipeline and an anti-surge backflow valve to further stabilize the working state of the equipment through backflow regulation and ensure the safe and stable operation of the system. The steam outlet of the steam compressor 6.2 is connected through a pipeline to the steam inlet of the compressor outlet desuperheating device 6.3. The steam outlet of the compressor outlet desuperheating device 6.3 is connected through a pipeline to an industrial steam (steam supply pressure > Po) pipeline to supply industrial steam.

[0039] In this embodiment, each device is configured as a single unit. As an improvement to the technical solution, the dual thermal storage electric heating cascade temperature-raising and steam supply system can be flexibly configured according to the actual production, storage and supply scale, equipment capacity and site conditions. Among them, the buffer water tank 1.1, spherical tank water supply pump 1.2, deaerator water supply pump 1.3, boiler feed water pump 2.1, electrode steam boiler 2.2, steam electric heater 3.2, spherical tank 4.1, compressor inlet desuperheating device 6.1, steam compressor 6.2, compressor outlet desuperheating device 6.3, etc., can be configured in parallel with multiple units according to relevant standards and specifications, usage requirements and backup needs.

[0040] Working process of this invention: To facilitate quantitative analysis of system parameters and study of operating conditions, and to ignore the influence of pressure drop, the pressure parameters of the steam-water medium are defined as follows: the pressure value of the steam-water medium under high pressure is denoted as PH, and the pressure value under low pressure is denoted as PL.

[0041] The following describes the dual-storage thermal electric heating cascade temperature-raising steam supply system of the present invention with a steam supply pressure ≤ Po (see structural schematic diagram). Figure 1 ), and elaborate on its working process: The demineralized water output from the chemical demineralized water system is first stored in a buffer tank 1.1. The demineralized water in the buffer tank 1.1 is distributed through two paths: one path is transported to the spherical tank 4.1 via the spherical tank makeup water pump 1.2; the other path is sent to the deaerator 1.4 via the deaerator makeup water pump 1.3, where it mixes and exchanges heat with the deaerated heating steam from the low-pressure steam distribution cylinder 3.1. After deaeration, it becomes feedwater, which is then transported to the electrode steam boiler 2.2 by the boiler feedwater pump 2.1.

[0042] The feedwater is heated by the high-pressure electrode 2.4 in the electrode steam boiler 2.2 to generate high-pressure saturated steam at pressure PH. This high-pressure saturated steam enters the high-pressure steam distributor 2.3 and is divided into two outputs: the first output of PH high-pressure steam is reduced to low-pressure steam at pressure PL by the boiler direct supply pressure reducing valve 3.3 and then sent to the low-pressure steam distributor 3.1; the second output of PH high-pressure steam is directly introduced into the spherical tank 4.1, where the medium is heated to high-parameter saturated water and saturated steam through heat exchange, thereby completing the heat storage process.

[0043] As flash evaporation proceeds, the pressure of the saturated water stored in the spherical tank 4.1 gradually decreases from high pressure PH to low pressure PL. After being flashed and depressurized by the flash pressure reducing valve 4.2, it is converted into low-pressure steam (PL) and sent to the low-pressure steam distribution cylinder 3.1.

[0044] The steam output from the low-pressure steam distribution cylinder 3.1 is divided into three paths: the first path is the PH high-pressure steam directly supplied by the electrode steam boiler, which is reduced to PL low-pressure steam by the boiler direct supply pressure reducing valve 3.3, and then sent to the steam electric heater 3.2 for heating before being supplied to the outside as industrial steam (steam supply pressure ≤ Po); the second path is the steam that is sent to the deaerator 1.4 for heating and deoxygenation as mentioned above; the third path is the PL low-pressure steam supplied by the flash evaporation pressure reduction of the spherical tank 4.1, which is sent to the steam heating and heat storage module 5 for heating before being supplied to the outside as industrial steam (steam supply pressure ≤ Po).

[0045] When the steam heating and heat storage module 5 adopts the molten salt heat storage form, the low-temperature molten salt in the low-temperature molten salt tank 5.1-1 is sent to the molten salt electric heater 5.1-3 via the low-temperature molten salt pump 5.1-2. After being heated by high-voltage electric heating, it is heated to high-temperature molten salt and sent to the high-temperature molten salt tank 5.1-4. The high-temperature molten salt in the high-temperature molten salt tank 5.1-4 is sent to the molten salt-steam heat exchanger 5.1-6 via the high-temperature molten salt pump 5.1-5. The medium-pressure saturated steam from the low-pressure steam distribution cylinder 3.1 is heated to provide industrial steam for external supply. The high-temperature molten salt is cooled down to low-temperature molten salt and returned to 5.1-1.

[0046] When the steam heating and heat storage module 5 adopts solid heat storage, the solid electric heat storage device 5.2-1 stores the heat energy in the form of sensible heat by heating the heat storage material with high voltage. The low-temperature gas from the gas-steam heat exchanger 5.2-2 is sent into the solid electric heat storage device 5.2-1 by the high-temperature circulating fan 5.2-3. The heat storage material of the solid electric heat storage device 5.2-1 is heated and heated to a high-temperature gas, which is then input into the gas-steam heat exchanger 5.2-2. The medium-pressure saturated steam from the low-pressure steam separator 3.1 is heated and heated to a temperature that is supplied to the outside as industrial steam. The high-temperature gas is cooled down to a low-temperature gas and returned to the high-temperature circulating fan 5.2-3. After being pressurized, it is sent back into the solid electric heat storage device 5.2-1. Thus, the heat storage material and the high-temperature gas repeatedly undergo heating-storage-extraction and heat release processes.

[0047] The following describes the dual-storage thermal electric heating cascade temperature-raising steam supply system of the present invention with a steam supply pressure > P0 (see structural schematic diagram). Figure 4 ), and elaborate on its working process: The dual-storage thermal electric heating cascade temperature-raising steam supply system with a steam supply pressure > Po adds a series-connected steam compression module 6 at the end of the process compared to the system with a steam supply pressure ≤ Po (the equipment and piping within the module are all adapted to the > Po pressure condition). The structure, connection relationship, and working process of the first 5 modules are the same and will not be described again. The differences and additions are as follows: The outlet steam from the steam electric heater 3.2 and the outlet steam from the steam heating and heat storage module 5 are supplied to the steam compressor 6.2 after being temperature-adjusted by the compressor inlet desuperheating device 6.1. After being pressurized and heated by the steam compressor 6.2, the steam is then temperature-adjusted by the compressor outlet desuperheating device 6.3 before being supplied as industrial steam (supply pressure > Po). The steam compressor 6.2 is equipped with a variable frequency speed control device, which can stabilize the outlet steam pressure through variable frequency speed control technology; at the same time, the compressor inlet desuperheating device 6.1 ensures that the superheat of the inlet steam does not exceed the limit, and the compressor outlet desuperheating device 6.3 maintains a constant outlet steam temperature.

[0048] This invention discloses a dual-storage electric heating cascade temperature-raising and steam supply system (steam supply pressure ≤ Po). During the heat storage stage, the high-pressure PH steam produced by the electrode steam boiler is output in two paths. One path of high-pressure PH steam is reduced to low pressure by the boiler direct supply pressure reducing valve 3.3, and then heated by the steam electric heater 3.2 to provide industrial steam (steam supply pressure ≤ Po). The other path of high-pressure PH steam is input into a spherical tank for heat storage. Simultaneously, the high-pressure electric heating steam temperature-raising and heat storage module 5 is activated, allowing the thermal energy to be stored in the form of sensible heat in high-temperature molten salt or solid heat storage material. During the heat release stage, the steam provided by the flash evaporation in the spherical tank is successively released through the spherical tank, primarily providing latent heat; and through molten salt / solid heat storage, primarily providing superheated sensible heat, before being supplied as industrial steam (steam supply pressure ≤ Po).

[0049] This invention discloses a dual-storage electric heating cascade temperature-raising and steam supply system (steam supply pressure > Po). During the heat storage stage, the high-pressure PH steam produced by the electrode steam boiler is output in two paths. One path of the high-pressure PH steam is depressurized to low pressure by the boiler direct supply pressure reducing valve 3.3, then heated by the steam electric heater 3.2, and then sent to the steam compressor 6.2 through the compressor inlet desuperheating device 6.1. After being pressurized and heated by the steam compressor 6.2, it is then regulated by the compressor outlet desuperheating device 6.3 and supplied as industrial steam (steam supply pressure > Po). The other path of the high-pressure PH steam is input into the spherical tank for heat storage. Simultaneously, the high-pressure electric heating steam temperature-raising and heat storage module 5 is turned on and put into operation, so that the heat energy is stored in the form of sensible heat in the high-temperature molten salt or solid heat storage material. The steam provided by the flash evaporation in the spherical tank during the heat release stage is successively supplied by the latent heat of the steam through the heat release of the spherical tank, and by the heat release of the molten salt / solid heat storage to provide part of the sensible heat of the steam through the heat release of the molten salt / solid heat storage. Then it is sent to the steam compressor 62 through the compressor inlet desuperheating device 6.1. After the steam compressor 6.2 pressurizes and increases the temperature, it is then supplied to the outside as industrial steam (steam supply pressure > Po) after being adjusted by the compressor outlet desuperheating device 6.3.

[0050] Through the above-described working process, the dual-storage thermal electric heating cascade temperature-raising and steam supply system disclosed in this invention can realize the complete process of demineralized water replenishment, steam preparation, heat storage and release, direct steam supply, stored steam supply and external steam supply; the coordinated action of each device and valve can ensure the stable operation of the medium under different parameter conditions and flow paths.

[0051] The present invention discloses a dual thermal storage electric heating cascade temperature-raising steam supply system that not only solves the problem of industrial steam supply during peak and valley periods, but also achieves the problem of "peak and valley load" matching (heat storage during valley periods and heat release during peak periods). Furthermore, through the design of deoxygenation and safety valves, the system ensures long-term stable operation. Compared with a single thermal storage system, the technical reliability, economic applicability and energy efficiency are significantly improved.

[0052] The operating mode and operation process of this invention system: This invention addresses the core needs of "instant supply" and "energy storage" for industrial steam, and divides the operating modes into four main categories: direct industrial steam supply mode from electrode steam boilers; electric heating and heat storage mode with dual heat storage devices; heat release mode from dual heat storage devices to supply industrial steam; and heat release mode from a single heat storage device to supply industrial steam.

[0053] The following pertains to the dual-storage thermal electric heating cascade temperature-raising steam supply system of the present invention with a steam supply pressure ≤ Po (e.g.) Figure 1 (As shown), the operating mode and operation process of the system of the present invention are explained in detail: 1. Electrode Steam Boiler Direct Industrial Steam Supply Mode: The system operates the feedwater module 1, electrode steam generation module 2, and direct steam supply regulating module 3 (including its sub-component, the steam electric heater 3.2). The direct-supply electric gate valve 3.4 is in the open state, while the energy-storage electric gate valve 3.5 is in the closed state. This mode is used during off-peak hours in the power system, and its core function is to directly provide immediate industrial steam to the industrial sector.

[0054] 2. Electric heating thermal storage mode of dual thermal storage device: During the operation of the water supply module 1, electrode steam generation module 2, and spherical tank thermal storage and release module 4, the flash pressure reducing valve 4.2 and the electric gate valve 3.5 are both closed; During the simultaneous operation of the steam heating thermal storage module 5: When the steam heating thermal storage module 5 adopts the form of solid thermal storage, the high-voltage electric heating solid electric thermal storage device 5.2-1 is started, so that the heat energy is stored in the internal thermal storage material in the form of sensible heat, and the gas-steam heat exchanger 5.2-2 and the high-temperature circulating fan 5.2-3 are both shut down; When the steam heating and heat storage module 5 adopts molten salt heat storage, the low-temperature molten salt pump 5.1-2 and the molten salt electric heater 5.1-3 are put into operation. High-voltage electric heating converts the low-temperature molten salt into high-temperature molten salt, allowing the thermal energy to be stored as sensible heat in the molten salt within the high-temperature molten salt tank 5.1. The high-temperature molten salt pump 5.1-5 and the molten salt-steam heat exchanger 5.1-6 are both shut down. Depending on actual operating conditions, the heat storage process of the steam heating and heat storage module 5 does not need to be completely synchronized with the heat storage process of the spherical tank heat storage and release module 4; both can be started earlier or later depending on the steam load. This mode is mainly used during off-peak hours in the power system, providing immediate industrial steam to the industrial sector while simultaneously completing the energy storage of the dual heat storage devices.

[0055] 3. Dual Thermal Storage Unit Heat Release for Industrial Steam Supply Mode: The heat release process of the spherical tank heat storage module 4, the heat release process of the steam heating and heat storage module 5, and the direct steam supply regulating module 3 are activated. The flash pressure reducing valve 4.2 and the power storage electric gate valve 3.5 are both open, while the direct power supply electric gate valve 3.4 is closed. The makeup water module 1, the electrode steam generating module 2, and the heat storage processes of the spherical tank heat storage module 4 and the steam heating and heat storage module 5 are deactivated. This mode is mainly used during peak power system periods, providing industrial steam by simultaneously releasing stored heat from the dual thermal storage units.

[0056] 4. Single thermal storage unit heat release mode for industrial steam supply: The heat release process of the spherical tank thermal storage and heat release module 4 and the direct steam supply regulating module 3 (including its sub-component steam electric heater 3.2) are activated. The flash pressure reducing valve 4.2 and the direct-supply electric gate valve 3.4 are both open, while the storage electric gate valve 3.5 is closed. The makeup water module 1, the electrode steam generating module 2, and the entire heat storage process of the spherical tank thermal storage and heat release module 4, as well as the entire heat storage and release process of the steam heating and heat storage module 5, are shut down. This mode is mainly used in scenarios where the power system operates during peak hours and the demand for industrial steam superheat is not high, to provide industrial steam to meet production needs.

[0057] This invention relates to a dual-storage thermal electric heating cascade steam supply system with a steam supply pressure > Po (e.g., Figure 4 (As shown) The start / stop and opening of pipes and valves between modules 1 to 5 and between them in each operating mode, and the dual thermal storage electric heating cascade temperature-raising steam supply system with a steam supply pressure ≤ Po (e.g.) Figure 1 The same as shown; it should be noted that the start and stop method of the steam compression module 6 is as follows: the steam compression module 6 is shut down as long as the system before each mode module 6 does not output steam, and the steam compression module 6 is activated as long as the system before each mode module 6 outputs steam, so as to upgrade the steam output by the previous system and provide industrial steam (steam supply pressure > Po).

[0058] Based on the above four main operating modes, and combined with actual industrial steam load, electricity time characteristics and other operating conditions, other auxiliary operating modes (such as multi-module joint operation mode, emergency standby operation mode, etc.) can be further derived.

Claims

1. A dual-storage thermal electric heating cascade temperature-raising and steam supply system, characterized in that, When the steam supply pressure is ≤ Po (Po is the steam supply pressure threshold, preferably 1.6 MPa.g, which can be adjusted to 1.2 MPa.g~2.0 MPa.g according to actual needs), the system includes a water supply module (1), an electrode steam generation module (2), a steam direct supply regulation module (3), a spherical tank heat storage and heat release module (4), and a steam temperature rise and heat storage module (5). The makeup water module (1) includes a buffer tank (1.1), a spherical tank makeup water pump (1.2), a deaerator makeup water pump (1.3), a deaerator (1.4), and a deaerator steam pressure reducing valve (1.5). The first makeup water inlet of the buffer tank (1.1) is connected to the chemical demineralized water system, the second makeup water outlet is connected to the makeup water inlet of the spherical tank makeup water pump (1.2), and the third makeup water outlet is connected to the makeup water inlet of the deaerator makeup water pump (1.3). The makeup water outlet of the spherical tank makeup water pump (1.2) is connected to the first makeup water inlet of the spherical tank (4.1). The makeup water outlet of the deaerator makeup water pump (1.3) is connected to the first makeup water inlet of the deaerator (1.4). The second steam inlet of the deaerator (1.4) is connected to the fifth steam outlet of the low-pressure steam distribution cylinder (3.1) through a pipe equipped with a deaerator steam pressure reducing valve (1.5), and the third water outlet is connected to the water inlet of the boiler feed water pump (2.1). The electrode steam generating module (2) includes a boiler feedwater pump (2.1), an electrode steam boiler (2.2), a high-pressure steam distribution cylinder (2.3), and a high-pressure electrode (2.4). The feedwater outlet of the boiler feedwater pump (2.1) is connected to the feedwater inlet of the electrode steam boiler (2.2). The high-pressure electrode (2.4) is connected to a high-voltage power supply through an electrical circuit. The steam outlet of the electrode steam boiler (2.2) is connected to the first steam inlet of the high-pressure steam distribution cylinder (2.3). The second steam outlet of the high-pressure steam distribution cylinder (2.3) is connected to the second steam inlet of the low-pressure steam distribution cylinder (3.1) through a pipe equipped with a boiler direct supply pressure reducing valve (3.3). The third steam outlet is connected to the second steam inlet of the spherical tank (4.1). The steam direct supply regulating module (3) includes a low-pressure steam distribution cylinder (3.1), a steam electric heater (3.2), a boiler direct supply pressure reducing valve (3.3), a direct power supply electric gate valve (3.4), and a storage power supply electric gate valve (3.5). The third steam outlet of the low-pressure steam distribution cylinder (3.1) is connected to the steam inlet of the steam electric heater (3.2) through a pipe equipped with a direct power supply electric gate valve (3.4), and the fourth steam outlet is connected to the steam inlet of the steam heating and heat storage module (5) through a pipe equipped with a storage power supply electric gate valve (3.5). The steam outlet of the steam electric heater (3.2) is connected to an industrial steam pipeline with a steam supply pressure ≤ Po, and its power input terminal is connected to a high-voltage power supply through an electrical circuit. The spherical tank heat storage and heat release module (4) includes a spherical tank (4.1) and a flash pressure reducing valve (4.2). The third steam outlet of the spherical tank (4.1) is connected to the first steam inlet of the low-pressure steam distribution cylinder (3.1) through a pipe equipped with the flash pressure reducing valve (4.2). The steam outlet of the steam heating and heat storage module (5) is connected to an industrial steam pipeline with a steam supply pressure ≤ Po, and its high-voltage power supply is connected to the same position as the high-voltage power supply of the high-voltage electrode (2.4).

2. The dual-storage thermal electric heating cascade temperature-raising and steam supply system according to claim 1, characterized in that, When the steam supply pressure is greater than Po, the system also includes a steam compression module (6). The steam compression module (6) includes a compressor inlet desuperheating device (6.1), a steam compressor (6.2), and a compressor outlet desuperheating device (6.3). The steam outlet of the steam electric heater (3.2) and the steam outlet of the steam heating and heat storage module (5) are connected to the steam inlet of the compressor inlet desuperheating device (6.1) through a single pipe. The steam outlet of the compressor inlet desuperheating device (6.1) is connected to the steam inlet of the steam compressor (6.2). The steam outlet of the steam compressor (6.2) is connected to the steam inlet of the compressor outlet desuperheating device (6.3). The steam outlet of the compressor outlet desuperheating device (6.3) is connected to an industrial steam pipeline with a steam supply pressure > Po.

3. A method for operating a dual-storage thermal electric heating cascade temperature-raising and steam supply system, applied to the system described in claim 1 or 2, characterized in that, This includes the following core processes: (1) Makeup water treatment process: Chemically demineralized water is stored in a buffer tank (1.1), and is transported to the spherical tank (4.1) by the spherical tank makeup water pump (1.2), or sent to the deaerator (1.4) by the deaerator makeup water pump (1.3). After being mixed with the steam output from the low-pressure steam separator (3.1) for deoxygenation, it is transported to the electrode steam boiler (2.2) by the boiler feed water pump (2.1). (2) Steam preparation and cascade storage and supply process: The feedwater is heated in the electrode steam boiler (2.2) to generate high-pressure saturated steam. After entering the high-pressure steam distribution cylinder (2.3), it is divided into two paths. One path is reduced to low-pressure steam through the boiler direct supply pressure reducing valve (3.3) and sent to the low-pressure steam distribution cylinder (3.1). After being heated by the steam electric heater (3.2), the industrial steam with a supply pressure ≤ Po is output. The other path is sent to the spherical tank (4.1) to complete heat storage. At the same time, the steam heating and heat storage module (5) is put into operation to store thermal energy. (3) Dual heat storage and heat release process: The medium in the spherical tank (4.1) is flashed into low-pressure steam through the flash pressure reducing valve (4.2), and then sent into the low-pressure steam distribution cylinder (3.1). The superheated sensible heat is supplemented by the steam heating and heat storage module (5), and the industrial steam with a supply pressure ≤ Po is output. (4) High-pressure steam supply switching process: When the required steam supply pressure is > Po, the steam output by the steam electric heater (3.2) and the steam output by the steam heating and heat storage module (5) (the two are output at different times depending on the operating mode, such as the electrode steam boiler direct steam supply mode and the single heat storage heat release steam supply mode, where only the former is output, and the double heat storage heat release steam supply mode, where only the latter is output) are both temperature-adjusted by the compressor inlet de-temperature device (6.1) and sent to the steam compressor (6.2) for pressure and temperature increase, and then temperature-controlled by the compressor outlet de-temperature device (6.3) to output industrial steam with a supply pressure > Po.

4. The dual-storage thermal electric heating cascade temperature-raising and steam supply system according to claim 1 or 2, characterized in that, The steam heating and heat storage module (5) can take any of the following forms: Form 1 (Molten Salt Thermal Storage): Includes a low-temperature molten salt tank (5.1-1), a low-temperature molten salt pump (5.1-2), a molten salt electric heater (5.1-3), a high-temperature molten salt tank (5.1-4), a high-temperature molten salt pump (5.1-5), and a molten salt-steam heat exchanger (5.1-6); the molten salt outlet of the low-temperature molten salt tank (5.1-1) is connected to the molten salt inlet of the molten salt electric heater (5.1-3) via the low-temperature molten salt pump (5.1-2), and the molten salt outlet of the molten salt electric heater (5.1-3) is connected to the high-temperature molten salt tank (5.1-6). The molten salt inlet of the high-temperature molten salt tank (5.1-4) is connected to the third molten salt inlet of the molten salt-steam heat exchanger (5.1-6) via the high-temperature molten salt pump (5.1-5), and the fourth molten salt outlet of the molten salt-steam heat exchanger (5.1-6) flows back to the molten salt inlet of the low-temperature molten salt tank (5.1-1); the first steam inlet of the molten salt-steam heat exchanger (5.1-6) is the steam inlet of the steam heating and heat storage module (5), and the second steam outlet is the steam outlet of the steam heating and heat storage module (5); Form 2 (Solid Heat Storage): Includes a solid electric heat storage device (5.2-1), a gas-steam heat exchanger (5.2-2), and a high-temperature circulating fan (5.2-3); the gas outlet of the solid electric heat storage device (5.2-1) is connected to the third gas inlet of the gas-steam heat exchanger (5.2-2) via a duct, and the fourth gas outlet of the gas-steam heat exchanger (5.2-2) is returned to the gas inlet of the solid electric heat storage device (5.2-1) via the high-temperature circulating fan (5.2-3); the first steam inlet of the gas-steam heat exchanger (5.2-2) is the steam inlet of the steam heating and heat storage module (5), and the second steam outlet is the steam outlet of the steam heating and heat storage module (5).

5. The dual-storage thermal electric heating cascade temperature-raising and steam supply system according to claim 1 or 2, characterized in that, The deaerator (1.4), electrode steam boiler (2.2), high-pressure steam distributor (2.3), low-pressure steam distributor (3.1), and spherical tank (4.1) are all equipped with safety valves, which automatically open to release pressure when the pressure rises to the set pressure.

6. The dual-storage thermal electric heating cascade temperature-raising and steam supply system according to claim 4, characterized in that, The molten salt used in the molten salt electric heater (5.1-3) is a binary molten salt or a ternary molten salt; the heat storage material of the solid electric heat storage device (5.2-1) is magnesium oxide brick, ceramic material, alloy material or modified graphite block.

7. The dual-storage thermal electric heating cascade temperature-raising and steam supply system according to claim 2, characterized in that, The steam compressor (6.2) is equipped with a variable frequency speed control device and is configured with an anti-surge backflow pipeline and an anti-surge backflow valve.

8. The dual-storage thermal electric heating cascade temperature-raising and steam supply system according to claim 1 or 2, characterized in that, At least one of the following devices is configured in parallel: buffer tank (1.1), spherical tank water supply pump (1.2), deaerator water supply pump (1.3), boiler feed pump (2.1), electrode steam boiler (2.2), steam electric heater (3.2), spherical tank (4.1), compressor inlet desuperheating device (6.1), steam compressor (6.2), and compressor outlet desuperheating device (6.3).

9. The operation method of the dual-storage thermal electric heating cascade temperature-raising and steam supply system according to claim 3, characterized in that, In step (2), the heat storage process of the steam heating and heat storage module (5) and the heat storage process of the spherical tank (4.1) can be started asynchronously; in step (3), the steam output flow rate of the spherical tank (4.1) is adjusted by the opening of the flash pressure reducing valve (4.2), and the molten salt circulation flow rate or gas circulation flow rate of the steam heating and heat storage module (5) is linked with the set temperature of the outlet steam of the steam heating and heat storage module (5); in step (4), the anti-surge backflow valve is automatically opened when the inlet flow rate of the steam compressor (6.2) is less than 70% of the rated value.

10. The operation method of the dual-storage thermal electric heating cascade temperature-raising and steam supply system according to claim 3, characterized in that, It also includes at least one of the following operating modes: Mode 1: Electrode steam boiler direct steam supply mode: When the steam supply pressure is ≤ Po, the makeup water module (1), electrode steam generation module (2) and steam direct supply regulation module (3) are put into operation, the direct power electric gate valve (3.4) and steam electric heater (3.2) are opened, and the storage power electric gate valve (3.5) is closed; when the steam supply pressure is > Po, the steam compression module (6) is put into operation in addition. Mode 2: Dual thermal storage electric heating thermal storage mode: the water supply module (1), electrode steam generation module (2) and spherical tank thermal storage and heat release module (4) are put into operation for thermal storage process, the flash evaporation pressure reducing valve (4.2) and the power storage electric gate valve (3.5) are closed, and the steam heating thermal storage module (5) is put into operation simultaneously for thermal storage process; Mode 3: Dual heat storage and heat release steam supply mode: When the steam supply pressure is ≤ Po, the water supply module (1) and electrode steam generation module (2) are shut down, and the heat release process of the spherical tank heat storage and heat release module (4) and the heat release process of the steam temperature rise and heat storage module (5) are put into operation simultaneously. The flash steam pressure reducing valve (4.2) and the power storage electric gate valve (3.5) are opened, and the direct power electric gate valve (3.4) and the steam electric heater (3.2) are closed. When the steam supply pressure is > Po, the steam compression module (6) is put into operation in addition. Mode 4: Single heat storage and heat release steam supply mode: When the steam supply pressure is ≤ Po, the heat release process of the steam heating and heat storage module (5) is stopped, the heat release process of the spherical tank heat storage and heat release module (4) is started, the flash steam pressure reducing valve (4.2), the direct power electric gate valve (3.4) and the steam electric heater (3.2) are opened, and the storage electric gate valve (3.5) is closed; when the steam supply pressure is > Po, the steam compression module (6) is additionally started.

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