System and method for replacing coal-fired power plant with high-temperature gas cooled reactor for steam supply

Abstract

The invention relates to the technical field of nuclear energy heat supply and industrial steam supply, in particular to a system and method for replacing coal-fired power plant steam supply with a high-temperature gas cooled reactor. The system for replacing the coal-fired power plant steam supply with the high-temperature gas cooled reactor comprises a heat energy output unit which comprises a high-temperature gas cooled reactor body and a primary loop helium circulation system connected with the high-temperature gas cooled reactor body; the steam generating unit comprises a steam generator, the primary side of the steam generating unit is connected with the primary loop helium circulating system, and the secondary side of the steam generating unit is connected with a water supply system; the steam supply pipe network unit comprises an original main steam pipeline and an original branch pipeline of the coal-fired power plant; the heat storage adjusting unit is connected with the steam generating unit and the steam supply pipe network unit; and the control and safety unit is used for carrying out linkage control and safety protection on the heat energy output unit, the steam generation unit, the heat storage adjusting unit and the steam supply pipe network unit. A set of complete emergency steam supply plan is established, seamless connection of steam supply interruption is realized, and frequent peak regulation or energy waste of a reactor is avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nuclear energy heat supply and industrial steam supply, and particularly relates to a high-temperature gas cooled reactor replacing a coal-fired power plant steam supply system and method. BACKGROUND

[0002] During long-term operation, the coal-fired power plant has formed a mature industrial steam supply pipe network system, site layout and supporting facilities, and has stable steam supply capacity. However, the steam supply system generally has problems of high energy consumption, large pollution and high carbon emission intensity, and the steam supply parameters are easily affected by unit load fluctuations, and it is difficult to meet the high requirements of modern industrial users on steam parameter stability and cleanliness.

[0003] As an advanced nuclear energy technology, the high-temperature gas cooled reactor has advantages of high safety, high outlet temperature (up to 500-950 DEG C), long fuel replacement period and multi-purpose heat supply, and is an ideal clean heat source for replacing fossil energy heat supply. If the high-temperature gas cooled reactor is used to replace the steam supply function of the coal-fired power plant, not only can the carbon emission and pollutant emission be significantly reduced, but also the green transformation of the energy structure can be realized. At present, if the high-temperature gas cooled reactor steam supply system is completely newly built, the steam pipe network and supporting auxiliary facilities need to be re-planned, the investment cost is high, the construction period is long, and it is difficult to realize large-scale application quickly. On the other hand, if the original steam supply infrastructure of the coal-fired power plant cannot be effectively utilized, resources will be wasted and the transformation cost will be increased.

[0004] Therefore, how to make full use of the existing old equipment (such as the main steam pipe, auxiliary system and water storage facility) of the coal-fired power plant, combine the high-temperature characteristics and stable output advantages of the high-temperature gas cooled reactor, and build an efficient, economical and reliable replacement steam supply system has become a key technical problem to be solved in the current promotion of clean heat transformation of the coal-fired power plant. SUMMARY

[0005] Therefore, the present application solves the technical problems of high energy consumption, large pollution and high carbon emission intensity in the prior art steam supply system.

[0006] To solve the above technical problems, the present application provides a high-temperature gas cooled reactor replacing a coal-fired power plant steam supply system, which comprises: a heat energy output unit comprising a high-temperature gas cooled reactor body and a one-loop helium circulation system connected with the high-temperature gas cooled reactor body; a steam generation unit comprising a steam generator, wherein a primary side of the steam generator is connected with the one-loop helium circulation system, and a secondary side of the steam generator is connected with a feedwater system for generating superheated steam; a steam supply pipe network unit comprising a main steam pipe and branch pipes originally in the coal-fired power plant, and the steam pipe is connected with the secondary side outlet of the steam generator; The thermal energy storage and regulation unit is connected to the steam generation unit and the steam supply network unit through pipelines and valves, and is used to store and release thermal energy to balance steam supply and demand. The control and safety unit is used to perform linkage control and safety protection on the heat output unit, the steam generation unit, the heat storage regulation unit and the steam supply network unit.

[0007] Preferably, the water supply system reuses the original deaerator and water treatment system of the coal-fired power plant; the water treatment system includes an ion exchange device and a reverse osmosis device.

[0008] Preferably, the steam supply network unit also reuses the original pressure reducing and desuperheating devices, drainage pipeline network and drainage valve group of the coal-fired power plant; the desuperheating and pressure reducing device includes a high-pressure pressure reducing valve and a low-pressure pressure reducing valve connected in parallel to meet the steam pressure requirements of different industrial users.

[0009] Preferably, the system also reuses the original auxiliary equipment of the coal-fired power plant; the auxiliary equipment includes condensate pumps and drain pumps for condensate recovery, and frequency converters for frequency conversion modification of the condensate pumps and drain pumps.

[0010] Preferably, it also includes the reuse of the original water storage and buffer facilities of the coal-fired power plant, wherein the water storage and buffer facilities include a softened water storage tank and a demineralized water tank for system replenishment.

[0011] Preferably, the heat storage regulating unit includes a molten salt heat storage tank, a heat storage heat exchanger, and a circulating pump. The primary side of the heat storage heat exchanger is connected to the circuit of the molten salt heat storage tank, and the secondary side of the heat storage heat exchanger can be selectively connected to the secondary side water supply of the steam generator or to the steam in the main steam pipeline. The pipeline is equipped with an electric valve group for switching between heat storage and heat release modes.

[0012] Preferably, it also includes a steam parameter adjustment module, including a high-pressure desuperheating and pressure reducing device installed on the main steam pipeline, used to adjust the high-pressure steam generated by the steam generator to medium and low pressure parameters; and a steam mixer used to mix the supplementary steam generated by the thermal storage adjustment unit with the steam in the main steam pipeline.

[0013] Preferably, the control and safety unit includes a distributed control system for realizing the linkage control of reactor load, steam parameters and thermal storage status; and a safety subsystem, which integrates the original safety valve group and pressure interlock protection device of the coal-fired power plant, and adds a helium leak monitoring sensor and a steam overpressure emergency shut-off valve.

[0014] This invention also provides a method for replacing steam supply from coal-fired power plants with a high-temperature gas-cooled reactor, comprising: The heat generated by the high-temperature gas-cooled reactor is converted into superheated steam by a steam generator and transported to the main steam pipeline. After parameter adjustment, it is transported to industrial users through the branch pipeline. When the steam supply demand is lower than the reactor's minimum stable output, the excess heat is stored in the thermal storage and regulation unit. When the steam demand exceeds the current output of the reactor, the heat release mode of the thermal storage regulation unit is activated to generate supplementary steam, which is mixed with the main steam and then sent to the steam supply network unit. When the steam generator malfunctions, disconnect it from the main steam pipeline and activate the backup steam source to maintain steam supply.

[0015] Preferably, it also includes real-time monitoring of helium leakage and steam pressure. When the monitored values ​​exceed the safety threshold, the steam overpressure emergency shut-off valve is automatically triggered, and the reactor power is adjusted.

[0016] The technical solution of the present invention has the following advantages compared with the prior art: This invention discloses a high-temperature gas-cooled reactor as a substitute for the steam supply system of a coal-fired power plant, and establishes a complete emergency steam supply plan. When a steam generator suddenly fails, the fault source can be quickly isolated and the thermal storage system activated as an independent backup steam source, achieving a "seamless transition" in the event of a steam supply interruption. This significantly shortens unplanned downtime, ensures the continuity of production for downstream industrial users, and significantly enhances the overall reliability of the system. When the steam demand is lower than the reactor's minimum stable output, excess heat is stored in the thermal storage system. This avoids frequent peak shaving or energy waste in the reactor, converting potentially wasted heat energy into peak-shaving reserve energy, maximizing the overall energy utilization rate of the entire system. Based on an integrated DCS system, automated linkage control is achieved, eliminating the need for complex manual valve switching and parameter adjustments. This not only reduces operational difficulty and labor costs but also effectively avoids safety risks or steam supply interruptions caused by human error. Attached Figure Description

[0017] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein: Figure 1 This is a structural diagram of a high-temperature gas-cooled reactor replacing the steam supply system of a coal-fired power plant, provided by the present invention. Figure 2 This is a flowchart of a method for replacing steam supply from a coal-fired power plant with a high-temperature gas-cooled reactor, provided by the present invention. Detailed Implementation

[0018] The core of this invention is to provide a high-temperature gas-cooled reactor to replace the steam supply system of a coal-fired power plant and a method thereof. When the steam generator suddenly fails, the source of the failure can be quickly isolated and the thermal storage system can be activated as an independent backup steam source, which greatly shortens the unplanned downtime and ensures the continuity of production for downstream industrial users.

[0019] To enable those skilled in the art to better understand the present invention, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Please refer to Figure 1. Figure 1 The present invention provides a logic diagram for a high-temperature gas-cooled reactor to replace the steam supply system of a coal-fired power plant; the specific operation steps are as follows: The thermal energy output unit includes a high-temperature gas-cooled reactor body and a primary loop helium circulation system connected to the high-temperature gas-cooled reactor body; The steam generation unit includes a steam generator. The primary side of the steam generator is connected to the primary loop helium circulation system, and the secondary side of the steam generator is connected to a feedwater system for generating superheated steam. The feedwater system reuses the original deaerator and feedwater treatment system of the coal-fired power plant. The feedwater treatment system includes an ion exchange device and a reverse osmosis device.

[0021] The steam supply network unit includes the original main steam pipeline and branch pipelines of the coal-fired power plant. The steam pipeline is connected to the secondary outlet of the steam generator. The steam supply network unit also reuses the original pressure reducing and desuperheating device, condensate pipeline network and condensate valve group of the coal-fired power plant. The desuperheating and pressure reducing device includes a high-pressure pressure reducing valve and a low-pressure pressure reducing valve set in parallel to meet the steam pressure requirements of different industrial users.

[0022] The thermal energy storage and regulation unit is connected to the steam generation unit and the steam supply network unit via pipelines and valves. It is used to store and release thermal energy to balance steam supply and demand. The thermal energy storage and regulation unit includes a molten salt thermal energy storage tank, a thermal energy storage heat exchanger, and a circulating pump. The primary side of the thermal energy storage heat exchanger is connected to the circuit of the molten salt thermal energy storage tank. The secondary side of the thermal energy storage heat exchanger can be selectively connected to the secondary side feedwater of the steam generator or to the steam in the main steam pipeline. The pipeline is equipped with an electric valve group for switching between thermal energy storage and thermal energy release modes.

[0023] The control and safety unit is used for the coordinated control and safety protection of the heat output unit, the steam generation unit, the thermal storage regulation unit, and the steam supply network unit. The control and safety unit includes a distributed control system for the coordinated control of reactor load, steam parameters, and thermal storage status. The safety subsystem integrates the original safety valve group and pressure interlock protection device of the coal-fired power plant, and adds a helium leak monitoring sensor and a steam overpressure emergency shut-off valve.

[0024] In one embodiment, the original auxiliary equipment of the coal-fired power plant is reused; the auxiliary equipment includes a condensate pump and a drain pump for condensate recovery, and a frequency converter for frequency conversion modification of the condensate pump and the drain pump. The original water storage and buffer facilities of the coal-fired power plant are reused. The water storage and buffer facilities include softened water storage tanks and demineralized water tanks for system replenishment.

[0025] The steam parameter adjustment module includes a high-pressure desuperheating and pressure reducing device installed on the main steam pipeline, used to adjust the high-pressure steam generated by the steam generator to medium and low pressure parameters; and a steam mixer used to mix the supplementary steam generated by the thermal storage adjustment unit with the steam in the main steam pipeline.

[0026] Specifically, existing equipment (former facilities of coal-fired power plants) that can be utilized include: Steam supply pipeline system: The existing main steam pipeline is used as the main steam transport channel for the high-temperature gas-cooled reactor, and the connection with the new heat exchange system is achieved by switching valves. The branch pipes, pressure reducing and cooling devices and flow metering equipment on the industrial user side are reused, and only the interfaces are adapted. The existing condensate drainage network and valve assembly are retained to remove condensate from the system and ensure steam quality.

[0027] Auxiliary equipment: The existing condensate pumps and drain pumps are reused as power devices for condensate recovery in the system, and frequency conversion is used to adapt to changes in flow rate. The existing deaerator and feedwater treatment system are reused to ensure the quality of feedwater entering the secondary side of the high-temperature gas-cooled reactor. The existing circulating water pumps and cooling water pipe network are used to provide cooling water for the newly added steam condensation equipment.

[0028] Water storage and buffer facilities: The existing softened water storage tank and demineralized water tank will be retained as system makeup water reserve devices. The existing steam pressure stabilizing tank is used as a pressure buffer device in the steam supply system to stabilize the pressure at the end users.

[0029] New core equipment (high-temperature gas-cooled reactor system): High-temperature gas-cooled reactor body: It adopts a pebble bed or prismatic high-temperature gas-cooled reactor, and the helium coolant outlet temperature can reach 500-950℃. It outputs high-temperature thermal energy through the primary loop helium circulation system.

[0030] Steam generator system: The primary side is connected to the helium primary loop of the high-temperature gas-cooled reactor and uses a spiral tube or coaxial tube heat exchanger. The secondary side generates superheated steam with parameters of 3.5-10MPa and 300-540℃, which is connected to the existing main steam pipeline of the coal-fired power plant.

[0031] Thermal storage buffer device: A thermal storage system is adopted, which is connected to the secondary side of the steam generator through a heat exchanger; The stored thermal energy is released when the reactor is under low load or when steam demand is at its peak, ensuring the stability of steam supply.

[0032] Steam parameter control module: A new high-pressure desuperheater and pressure reducer is added to regulate the high-parameter steam generated by the high-temperature gas-cooled reactor to the medium and low pressure parameters required by the user (such as 1.0-4.0MPa, 200-300℃). A steam mixer is configured to achieve stable mixing of the output steam from the thermal storage system with the main steam.

[0033] System composition: Thermal output unit: Composed of high-temperature gas-cooled reactor body, primary loop helium circulation fan and pressure boundary, responsible for generating and outputting high-temperature thermal energy.

[0034] Steam generation unit: includes a steam generator and a secondary water supply system, which uses the heat of helium to generate superheated steam and is connected to the existing deaerator and water pump.

[0035] Thermal storage regulation unit: It consists of a molten salt thermal storage tank, a thermal storage heat exchanger and a circulating pump. The thermal storage / heat release mode is switched by valve switching.

[0036] Steam supply network unit: Taking the existing main steam pipeline of the coal-fired power plant as the core, it integrates the newly added parameter adjustment module and the reused branch pipeline to form a steam supply network covering industrial users.

[0037] Control and Safety Unit: Based on the DCS system, the reactor load, steam parameters, and thermal storage status are linked for control. The existing safety valve group and pressure interlock protection device of the coal-fired power plant are retained, and a new helium leakage monitoring and steam overpressure protection system is added.

[0038] This embodiment provides a method and mechanism for replacing the steam supply system of a coal-fired power plant with a high-temperature gas-cooled reactor, establishing a complete emergency steam supply plan. When a steam generator suddenly fails, the fault source can be quickly isolated and the thermal storage system activated as an independent backup steam source, achieving a "seamless transition" in the event of a steam supply interruption. This significantly shortens unplanned downtime, ensures the continuity of production for downstream industrial users, and significantly enhances the overall reliability of the system. When the steam demand is lower than the reactor's minimum stable output, excess heat is stored in the thermal storage system. This avoids frequent peak shaving or energy waste in the reactor, converting potentially wasted heat energy into peak-shaving reserve energy, maximizing the overall energy utilization rate of the entire system. Based on an integrated DCS system, automated linkage control is achieved, eliminating the need for complex manual valve switching and parameter adjustments. This not only reduces operational difficulty and labor costs but also effectively avoids safety risks or steam supply interruptions caused by human error.

[0039] like Figure 2 As shown, Figure 2 The present invention provides a method for replacing steam supply from coal-fired power plants with a high-temperature gas-cooled reactor, as detailed below: Step S201: The heat generated by the high-temperature gas-cooled reactor is converted into superheated steam by the steam generator and transported to the main steam pipeline. After parameter adjustment, it is transported to industrial users through the branch pipeline. When the steam supply demand is lower than the minimum stable output of the reactor, the excess heat is stored in the heat storage and regulation unit. Step S202: When the steam demand exceeds the current output of the reactor, the heat release mode of the thermal storage regulation unit is activated to generate supplementary steam, which is mixed with the main steam and sent to the steam supply network unit. Step S203: When the steam generator malfunctions, disconnect it from the main steam pipeline and activate the backup steam source to maintain steam supply; Step S204: Monitor helium leakage and steam pressure in real time. When the monitored value exceeds the safety threshold, automatically trigger the steam overpressure emergency shut-off valve and adjust the reactor power.

[0040] In one embodiment, normal operating conditions include: In the high-temperature gas-cooled reactor, the helium in the primary loop transfers heat to the secondary side of the steam generator, and the generated superheated steam enters the reused main steam pipe. Steam is regulated to the user's required parameters by the newly added desuperheater and pressure reducer, and then delivered to industrial users through the existing branch pipelines; When the steam supply is lower than the reactor's minimum stable output, the excess heat is stored in the molten salt storage tank through a heat exchanger.

[0041] Peak operating conditions include: When the user’s steam demand exceeds the reactor’s current output, the thermal storage system starts the heat release mode, and the heat from the molten salt is used to heat and supplement the steam through the heat exchanger. The supplementary steam is mixed with the main steam in a mixer before entering the pipeline network, and the system pressure is maintained stable through the existing pressure stabilizing tank.

[0042] Fault switching conditions include: If the steam generator malfunctions, immediately close the valve connecting it to the main steam pipeline and turn on the backup steam source (such as an independent steam supply from the thermal storage system). The existing drainage system is used to quickly drain condensate from the pipes, and the existing circulating water system is used to cool the faulty equipment.

[0043] This embodiment provides a method for replacing steam supply from coal-fired power plants with a high-temperature gas-cooled reactor (HTGR). By utilizing 60%-80% of the existing steam supply pipelines, auxiliary equipment, and site facilities of coal-fired power plants, the overall retrofit cost can be reduced and the construction period shortened. Combined with the stable heat output of the HTGR and the buffering regulation of the molten salt thermal storage system, steam supply parameter fluctuations can be controlled within ±5%, meeting the needs of precision industrial users. Compared to coal-fired steam supply, carbon emissions can be reduced by more than 80% over the entire life cycle, with no emissions of pollutants such as sulfur dioxide and nitrogen oxides. It inherits the inherent safety characteristics of the HTGR while reusing the mature pressure protection and emergency handling facilities of coal-fired power plants, providing dual protection for the steam supply system's safety. The parameter adjustment module can meet the steam parameter requirements of different industrial users (such as chemical, paper, and food processing), offering better adaptability than traditional coal-fired units.

[0044] Based on the above embodiments, this embodiment provides a detailed description of a high-temperature gas-cooled reactor to replace the steam supply system of a coal-fired power plant and a method thereof, as follows: This embodiment provides a system and method for industrial steam supply using a high-temperature gas-cooled reactor at the site of a typical 300MW coal-fired power plant. The original steam supply system of the power plant provides industrial steam at a pressure of 2.5MPa and a temperature of 260°C to a large chemical plant and a paper mill in the vicinity.

[0045] I. System Composition: This system mainly includes the following units: Thermal output unit: A pebble bed modular high-temperature gas-cooled reactor with a thermal power of 200MW is used as the core heat source. Its primary loop helium circulation system uses a main helium blower, and the helium outlet design temperature is 750℃.

[0046] Steam generation unit: The steam generator uses a spiral tube bundle heat exchanger. Its primary side is connected to a high-temperature helium gas circuit, while the secondary side feedwater system reuses the power plant's existing deaerator and feedwater treatment system consisting of "reverse osmosis + mixed bed" to ensure that the feedwater quality meets nuclear grade standards. This unit can generate superheated steam at a pressure of 7.0 MPa and a temperature of 500℃.

[0047] Steam supply network unit: This unit fully utilizes the power plant's existing main steam pipelines and branch pipelines leading to various users. Interface valves are adapted to connect with the new system. Simultaneously, the power plant's existing pressure reducing and desuperheating devices and drainage system are reused.

[0048] Thermal storage regulating unit: A molten salt thermal storage tank using binary nitrate (60% NaNO3 + 40% KNO3) as the thermal storage medium, designed to meet peak steam supply for 2 hours. The primary side of the thermal storage heat exchanger is connected to the molten salt circuit, and the secondary side is connected in parallel to the feedwater pipeline of the steam generator. Switching between storage and release modes is achieved via an electric valve assembly.

[0049] Steam parameter regulation module: A high-pressure desuperheater and pressure reducer is added to the main steam pipeline, which can regulate the steam from 7.0MPa and 500℃ to the user's required 2.5MPa and 260℃. At the same time, a steam mixer is installed to mix the main steam with the supplementary steam generated by the thermal storage system.

[0050] Control and Safety Unit: Upgraded based on the power plant's existing distributed control system (DCS), integrating the control logic of newly added equipment. The safety subsystem retains the original safety valve assembly, adds helium leak monitoring sensors at key points in the primary loop, and adds a steam overpressure emergency shut-off valve on the main steam pipeline near the steam generator.

[0051] II. Steam Supply Method and Procedure: The specific steps of the steam supply method in this embodiment are as follows: Normal steam supply conditions: The high-temperature gas-cooled reactor operates stably, with helium transferring heat to the steam generator to produce high-temperature, high-pressure superheated steam.

[0052] The steam enters the existing main steam pipeline and flows through a desuperheater and pressure reducer, where it is regulated to 2.5 MPa and 260°C.

[0053] The regulated steam is stably delivered to the chemical plant and paper mill through the existing branch pipelines.

[0054] When the user's steam consumption is lower than the reactor's minimum technical output (such as 50% of the rated load), the DCS system automatically adjusts the valve group to guide some of the high-temperature helium gas to the heat storage heat exchanger and store the excess heat energy in the molten salt tank.

[0055] Peak steam supply conditions: When a chemical plant starts up large equipment, causing a sudden increase in steam demand that exceeds the reactor's current output, the DCS system triggers peak mode.

[0056] The thermal storage regulating unit starts the heat release mode: low-temperature molten salt is pumped to the thermal storage heat exchanger to heat the feedwater from the water supply system and generate supplementary steam.

[0057] This supplementary steam is thoroughly mixed with the desuperheated and depressurized main steam in the mixer before being fed into the pipeline network to meet peak demand. The reuse of existing steam for pressure stabilization effectively smooths out pressure fluctuations.

[0058] Fault switching operation: Suppose that the steam generator needs to be isolated urgently due to a sudden leak. The DCS system immediately issues a command to close the emergency shut-off valve on its main outlet steam pipeline.

[0059] At the same time, the thermal storage system is fully opened, allowing it to serve as an independent backup steam source and directly supply steam to the pipeline network, thus achieving uninterrupted steam supply.

[0060] During the switchover, a reused drainage system is used to quickly drain condensate from the pipes, preventing water hammer. The existing circulating water system is reused to provide cooling for the out-of-service equipment.

[0061] III. Implementation Results: Significant benefits were achieved after the implementation of this embodiment: Economic efficiency: It reuses about 70% of the original pipelines and auxiliary equipment, reducing the total investment by about 40% compared to building a completely new system, and shortening the construction period by about 18 months.

[0062] Stability: Combining stable reactor operation and flexible adjustment of the thermal storage system, steam pressure fluctuations are controlled within ±3%, far exceeding the ±5% standard required by chemical plants.

[0063] Cleanliness: It completely replaces the original coal-fired boiler, reducing carbon dioxide emissions by about 500,000 tons per year and achieving zero emissions of pollutants (SO2, NOx).

[0064] Safety: To date, no safety incidents have occurred due to uncontrolled steam parameters or supply interruptions, demonstrating the system's high reliability.

[0065] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A high temperature gas cooled reactor steam supply system to replace a coal fired power plant, characterised in that, The system comprises: a thermal energy output unit comprising a high-temperature gas cooled reactor body and a one-loop helium circulation system connected to the high-temperature gas cooled reactor body; a steam generation unit comprising a steam generator, a primary side of the steam generator being connected to the one-loop helium circulation system, and a secondary side of the steam generator being connected to a feedwater system for generating superheated steam; a steam supply pipe network unit comprising original main steam pipes and branch pipes of a coal-fired power plant, the steam pipes being connected to an outlet of the secondary side of the steam generator; a thermal storage and adjustment unit connected to the steam generation unit and the steam supply pipe network unit via pipes and valves, for storing and releasing thermal energy to balance steam supply and demand; a control and safety unit for linkage control and safety protection of the thermal energy output unit, the steam generation unit, the thermal storage and adjustment unit, and the steam supply pipe network unit.

2. The high-temperature gas-cooled reactor replacement coal-fired power plant steam supply system according to claim 1, characterized by, The feedwater system reuses an original deaerator and feedwater treatment system of the coal-fired power plant; the feedwater treatment system comprises ion exchange devices and reverse osmosis devices.

3. The high-temperature gas-cooled reactor replacement coal-fired power plant steam supply system according to claim 1, characterized by, The steam supply pipe network unit also reuses original pressure and temperature reducing devices, a network of drain pipes, and a drain valve group of the coal-fired power plant; the pressure and temperature reducing devices comprise high-pressure and low-pressure pressure reducing valves arranged in parallel to adapt to the steam pressure requirements of industrial users.

4. The high-temperature gas-cooled reactor replacement coal-fired power plant steam supply system according to claim 1, characterized by, The system also reuses original auxiliary equipment of the coal-fired power plant; the auxiliary equipment comprises condensate water pumps and drain pumps for condensate water recovery, and frequency conversion controllers for frequency conversion reconstruction of the condensate water pumps and the drain pumps.

5. The high-temperature gas-cooled reactor replacement coal-fired power plant steam supply system according to claim 1, characterized by, The system also reuses original water storage and buffer facilities of the coal-fired power plant; the water storage and buffer facilities comprise softened water storage tanks and desalted water tanks for system water replenishment.

6. The high-temperature gas-cooled reactor replacement coal-fired power plant steam supply system of claim 1, wherein, The thermal storage and adjustment unit comprises a molten salt thermal storage tank, a thermal storage heat exchanger, and a circulating pump, a primary side of the thermal storage heat exchanger being connected to a loop of the molten salt thermal storage tank, and a secondary side of the thermal storage heat exchanger being selectively connected to a feedwater of the secondary side of the steam generator or to steam in the main steam pipes; electric valves are arranged on the pipes for switching between thermal storage and heat release modes.

7. The high-temperature gas-cooled reactor replacement coal-fired power plant steam supply system according to claim 1, characterized by, The system also comprises a steam parameter adjustment module comprising high-pressure pressure and temperature reducing devices arranged on the main steam pipes, for adjusting high-pressure parameter steam generated by the steam generator to medium and low-pressure parameters; and a steam mixer for mixing supplemental steam generated by the thermal storage and adjustment unit with steam in the main steam pipes.

8. The high-temperature gas-cooled reactor replacement coal-fired power plant steam supply system of claim 1, wherein, The control and safety unit comprises a distributed control system for linkage control of reactor load, steam parameters, and thermal storage state; and a safety subsystem integrated with original safety valves and pressure interlock protection devices of the coal-fired power plant, and additionally provided with a helium leakage monitoring sensor and a steam overpressure emergency shut-off valve.

9. A method of steam supply by a high-temperature gas-cooled reactor instead of a coal-fired power plant, characterized by, The system comprises: heat generated by a high-temperature gas cooled reactor is converted into superheated steam by a steam generator, is delivered to the main steam pipes, is adjusted in parameters, is delivered to industrial users through the branch pipes, and when steam supply demand is lower than the minimum stable output of the reactor, excess heat is stored in a thermal storage and adjustment unit. When the demand for steam exceeds the current output of the reactor, the heat release mode of the heat storage regulating unit is started to generate additional steam, which is mixed with the main steam and sent to the steam supply pipeline unit; When the steam generator fails, its connection with the main steam pipeline is cut off, and a backup steam source is enabled to maintain steam supply.

10. The method of claim 9, wherein the coal-fired power plant is replaced by a high-temperature gas-cooled reactor. Real-time monitoring of helium leakage and steam pressure is also included. When the monitored value exceeds the safety threshold, the steam overpressure emergency shut-off valve is automatically triggered, and the reactor power is adjusted.

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