Renewable energy cold start system for gas-steam combined cycle

Abstract

The invention discloses a renewable energy cold start-up system for gas-steam combined cycle. The renewable energy cold start-up system comprises a renewable energy heat gathering and taking device and a molten salt heat storage flash evaporation device. The renewable energy heat collecting and taking device comprises a fused salt heater and a renewable energy heat energy device, and a heat absorption side working medium circulating pipeline of the fused salt heater is connected with the renewable energy heat energy device; the molten salt heat storage flash evaporation device comprises a low-temperature molten salt tank, a high-temperature molten salt tank and a flash evaporator which are arranged on a working medium circulating pipeline on the heat release side of the molten salt heater; the steam-water side of the flash evaporator is connected with a waste heat boiler and a steam turbine of the gas-steam combined cycle unit through a unit preheating cycle pipeline; according to the system, solar energy is utilized for heat gathering, deep geothermal energy is utilized for heat extraction, molten salt is heated for heat storage, and before the combined cycle unit is started in a cold state, the stored heat is released, water is supplied to the flash evaporation unit, and machine heating steam is prepared, so that boiler starting fuel and auxiliary power are saved, decoupling of a gas turbine and a steam-water system in the unit starting process is promoted, and the starting efficiency is improved. And the optimization effect of cold start of the unit is greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of renewable energy utilization, and in particular to a renewable energy cold start system for a gas-steam combined cycle. Background Art

[0002] With the increasing number of installed capacity of renewable energy power generation, in order to coordinate the increasing renewable energy power generation for grid peak regulation and frequency regulation, the gas turbine combined cycle power generation technology with rapid start-up and flexible regulation has been rapidly developed. As the main force of grid peak regulation and frequency regulation, the gas turbine combined cycle unit needs to frequently adjust the output according to the change of grid load, resulting in the annual utilization hours of the unit generally being lower than the design value or rated value. In this case, a gas power station equipped with two sets of units usually only runs one set of units for rotation, so the number of cold starts of the unit is bound to increase. Frequent cold starts will bring adverse effects such as equipment wear, fatigue increase, operating cost increase and safety risk increase to the unit. Due to the fact that the heating rate of the steam-water system furnace and warm-up machine should not be too high, the conventional cold start process of the combined cycle unit will operate for a long time under the low-load condition of the gas turbine single cycle, which is not only inefficient and high in emissions, but also produces most of the unworked steam that is discharged from the bypass, causing energy loss. The entire cold start process is complex and time-consuming. It usually takes 5 to 7 hours from unit startup to full load, which seriously restricts the flexibility and response speed of peak and frequency regulation of gas turbine combined cycle units, and also has a certain impact on the economy of unit startup and operation.

[0003] Therefore, how to shorten the cold start time of combined cycle units has become an urgent problem to be solved in gas power plants. At present, combined cycle startup is mostly achieved by online monitoring of thermal stress and life evaluation of the steam-water system warm-up process, shortening the startup time and achieving optimization; then using the auxiliary steam of the neighboring machine in the same plant to preheat the steam-water system, shortening the startup time, and saving startup boiler fuel and plant electricity. Considering the safety of unit operation, the optimization effect of precise control is bound to be limited, and the use of auxiliary steam from the neighboring machine in the same plant for preheating is greatly limited by the operating status of the units in the entire plant. Summary of the invention

[0004] In response to the problems existing in the prior art, the present invention provides a cold start system of renewable energy and a gas-steam combined cycle system. The system utilizes solar energy to concentrate heat, deep geothermal energy to extract heat, and heats molten salt to store heat. Then, before the cold start of the combined cycle unit, the stored heat is released, the unit feed water is flashed, warm steam is prepared, the steam temperature rise rate is controlled, and the steam-water system is preheated, thereby realizing the transition from cold start to warm start of the unit, which greatly improves the optimization effect of cold start of the unit.

[0005] The present invention is achieved through the following technical solutions: A cold start system for renewable energy, comprising a renewable energy heat collection and extraction device and a molten salt heat storage and flash evaporation device; The renewable energy heat collection and heat extraction device comprises a molten salt heater and a renewable energy thermal energy device, and the working medium circulation pipeline on the heat absorption side of the molten salt heater is connected to the renewable energy thermal energy device; The molten salt heat storage flash evaporation device comprises a low-temperature molten salt tank, a high-temperature molten salt tank and a flash evaporator arranged on a working medium circulation pipeline on the heat release side of the molten salt heater; The steam-water side of the flash evaporator is connected to the waste heat boiler and the steam turbine of the gas-steam combined cycle unit through the unit preheating circulation pipeline.

[0006] Preferably, the renewable energy thermal energy device includes at least one heat source selected from the group consisting of a solar energy device, a geothermal energy device, boiler waste heat, high-temperature flue gas from a combined cycle unit, and auxiliary steam from an adjacent combined cycle unit.

[0007] Preferably, the working fluid pipelines of the solar energy device and the geothermal energy device are connected in parallel and connected in series with the working fluid circulation pipeline on the heat absorption side of the molten salt heater.

[0008] Preferably, a hot water storage tank is provided on the working medium circulation pipeline on the heat absorption side of the molten salt heater, the hot water storage tank is connected to the heat outlet on the heat absorption side of the molten salt heater through a water pump, and the heat absorption side outlet of the molten salt heater is connected to the hot water storage tank through a renewable energy thermal energy device.

[0009] Preferably, a second heat removal regulating valve group V4 is arranged between the working medium outlet of the renewable energy thermal energy device and the working medium circulation pipeline on the heat absorption side, and a first heat removal regulating valve group V3 is arranged at the outlet of the working medium circulation pipeline. The two heat removal regulating valve groups are used to control the working state of the renewable energy heat collection and heat removal device.

[0010] Preferably, the low-temperature molten salt tank is connected to the inlet of the heat release side of the molten salt heater, the outlet of the heat release side of the molten salt heater is connected to the molten salt pump through the high-temperature molten salt tank, the molten salt pump is connected to the working fluid inlet of the flash evaporator, and the working fluid outlet of the flash evaporator is connected to the low-temperature molten salt tank.

[0011] Preferably, a molten salt valve is provided on the circulation pipeline on the heat release side of the molten salt heater to control the working state of the molten salt heat storage flash evaporation device.

[0012] Preferably, the outlet of the steam-water side of the flash evaporator is connected to an electric auxiliary heater, which is connected to a waste heat boiler and a steam turbine in sequence through pipelines, and the steam turbine is connected to the inlet of the steam-water side of the flash evaporator through a warm-up pump.

[0013] Preferably, it also includes a boiler starting system; The boiler starting system is connected in parallel with the cold starting system of the renewable energy through the unit preheating circulation pipeline.

[0014] A gas-steam combined cycle system comprises the above-mentioned cold start system of renewable energy.

[0015] Compared with the prior art, the present invention has the following beneficial technical effects: The present invention proposes a renewable energy cold start system for a gas-steam combined cycle, which utilizes solar energy to collect heat, deep geothermal energy to extract heat, and heats molten salt to store heat. Then, before the combined cycle unit is cold-started, the stored heat is released to flash the unit feed water, prepare warm-up steam, control the steam temperature rise rate, and preheat the steam-water system, thereby saving startup boiler fuel and plant electricity, promoting the decoupling of the gas turbine and the steam-water system during the unit startup process, and greatly improving the optimization effect of the unit cold start. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The figure is a schematic structural diagram of a cold start system of a renewable energy source according to the present invention.

[0017] In the figure: 1 is a gas turbine; 2 is a waste heat boiler; 3 is a steam turbine; 4 is a generator; 5 is a condenser; 6 is a cooling tower; 7 is a feed water pump; 8 is a chimney; 9 is a warm-up pump; 10 is a flash evaporator; 11 is an electric auxiliary heater; 12 is a warm-up valve; 13 is a low-temperature molten salt tank; 14 is a molten salt heater; 15 is a high-temperature molten salt tank; 16 is a molten salt pump; 17 is a molten salt valve; 18 is a hot water storage tank; 19 is a water pump; 20 is a geothermal injection well, 21 is a geothermal production well; 22 is a solar collector; V1 is the first heat release regulating valve group, V2 is the second heat release regulating valve group; V3 is the first heat extraction regulating valve group, V4 is the second heat extraction regulating valve group. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0019] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0020] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0021] In the description of the embodiments of the present application, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings, or the orientation or position relationship in which the invented product is usually placed when used. It is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0022] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0023] In the description of the embodiments of the present application, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0024] See also Figure 1 , a cold start system of renewable energy, including a renewable energy heat collection and extraction device and a molten salt heat storage and flash evaporation device; The renewable energy heat collection and heat extraction device comprises a molten salt heater 14, a solar energy device and a geothermal energy device, and the heat absorption side working medium circulation pipeline of the molten salt heater 14 is connected to the solar energy device and the geothermal energy device; The molten salt heat storage flash evaporation device comprises a low-temperature molten salt tank 13, a high-temperature molten salt tank 15 and a flash evaporator 10 arranged on the working medium circulation pipeline on the heat release side of the molten salt heater 14; The steam-water side of the flash evaporator 10 is connected to the waste heat boiler and the steam turbine of the gas-steam combined cycle unit through the unit preheating circulation pipeline.

[0025] The system uses molten salt with good heat transfer performance, wide temperature range, low working pressure and low price as heat transfer and heat storage medium, combined with solar thermal collection technology and geothermal heat extraction technology, to effectively convert renewable energy into high-temperature thermal energy to heat molten salt for timely heat storage. Before the cold start of the combined cycle unit, the heat storage flash can be released to partially feed the condenser hot well water, and the start-up steam can be prepared in advance to supply the steam-water system for preheating the furnace and preheating the machine, realizing the decoupling of the gas turbine and the steam-water system, saving the start-up boiler fuel and plant electricity, and greatly improving the optimization effect of the unit's cold start.

[0026] In some embodiments, the solar energy device is a solar thermal concentrator 22 , and the geothermal energy device includes a geothermal injection well 20 and a geothermal production well 21 .

[0027] The working fluid outlets of the solar collector 22 and the geothermal production well 21 are connected to the hot water tank 18, the hot water tank 18 is connected to the water pump 19, the water pump 19 is connected to the heat absorption side inlet of the molten salt heater, and the heat absorption side outlet of the molten salt heater is respectively connected to the geothermal injection well 20 and the working fluid inlet of the solar collector 22.

[0028] A second heat-taking regulating valve group V4 is arranged between the working fluid outlet of the solar collector 22 and the geothermal production well 21 and the circulation pipeline, and a first heat-taking regulating valve group V3 is arranged at the heat-absorbing side outlet of the molten salt heater. The working state of the heat-taking device is controlled by the two heat-taking regulating valve groups.

[0029] The working states of the heat extraction device include using a solar thermal collector to extract heat, using a geothermal energy device to extract heat, using a solar thermal collector and a geothermal energy device to extract heat at the same time, and turning off the heat extraction.

[0030] The second heat extraction regulating valve group V4 includes three valves, two valves are arranged on the circulation pipeline and located on both sides of the outlet of the solar thermal collector, and the other valve is arranged at the outlet of the solar thermal collector.

[0031] The first heat extraction regulating valve group V3 includes three valves, two valves are respectively arranged at the working fluid inlet of the solar collector and the inlet of the geothermal injection well 20, and the other valve is arranged at the heat absorption side outlet of the molten salt heater.

[0032] The renewable energy heat collection and heat extraction device combines solar energy collection technology and deep geothermal energy collection technology, and aims to utilize renewable energy to heat the molten salt heat storage medium. It uses two sets of heat extraction control valve groups V3 and V4 for coordinated regulation. When the weather is clear and the sunlight is sufficient, the molten salt heat storage medium is heated by solar energy collection; when the weather is cloudy and rainy and the sunlight is weak, the molten salt heat storage medium is heated by deep geothermal energy.

[0033] In some embodiments, the solar thermal concentration technology of the solar device is not limited to the reflector dish type of concentration, but can also be a parabolic trough type, a concentrating linear Fresnel reflector type, a heliostat tower type and other solar thermal concentration forms, or a coupling form of the above multiple forms.

[0034] In some embodiments, the deep geothermal energy heat extraction technology of the geothermal energy device is not limited to one form of well circulation heat extraction technology, but can also be single-well closed circulation heat extraction technology, gravity heat pipe circulation heat extraction technology, single-well open circulation heat extraction technology, U-shaped well closed circulation heat extraction technology and multi-branch radial well circulation heat extraction technology, or a coupling form of the above multiple forms.

[0035] In some embodiments, the structure of the molten salt heat storage flash evaporation device is that the outlet of the low-temperature molten salt tank 13 is connected to the working fluid inlet of the molten salt heater 14, the working fluid outlet of the molten salt heater 14 is connected to the high-temperature molten salt tank 15, the high-temperature molten salt tank 15 is connected to the molten salt pump 16, the molten salt pump 16 is connected to the working fluid inlet of the flash evaporator, and the working fluid outlet of the flash evaporator is connected to the low-temperature molten salt tank 13.

[0036] A molten salt valve 17 is provided on the heat release side circulation pipeline of the molten salt heater 14 for controlling the working state of the molten salt heat storage flash evaporation device. In this embodiment, the molten salt valve 17 is provided at the working medium inlet of the flash evaporator 10 . In some embodiments, the working fluid of the molten salt heater 14 is not limited to a single form consisting of alkali metals or alkaline earth metals and halides, silicates, carbonates, nitrates, phosphates, etc., but can also be a coupled form consisting of the above multiple components.

[0037] In some embodiments, the heat source of the heating medium of the molten salt heater 14 is not limited to renewable energy, but can also be high-temperature flue gas from a combined cycle unit, auxiliary steam from an adjacent unit, or other waste heat from an industrial park, which can be connected in parallel with the above two renewable energy sources.

[0038] In some embodiments, the preheating circulation pipeline of the unit is connected to the steam-water side of the flash evaporator 10, the outlet of the steam-water side of the flash evaporator 10 is connected to the electric auxiliary heater 11, the electric auxiliary heater 11 is connected to the waste heat boiler 2 and the steam turbine 3 in sequence through pipelines, and the steam turbine 3 is connected to the inlet of the steam-water side of the flash evaporator 10 through a warm-up pump 9.

[0039] The molten salt heat storage flash evaporation device uses molten salt to store and release heat in a timely manner, flash evaporating the feed water in the unit preheating circulation pipeline to prepare startup steam. During operation, the low-temperature molten salt in the low-temperature molten salt tank 13 is heated by the molten salt heater 14 to form a high-temperature molten salt that enters the high-temperature molten salt tank 15 for heat storage. The high-temperature molten salt is regulated by the molten salt pump 16 and the molten salt valve 17 to enter the flash evaporator 10. After flashing part of the condenser hot well feed water as a heat source to prepare steam, it returns to the low-temperature molten salt tank 13 to form a cycle. The prepared startup steam is supplied to the steam-water system for preheating the furnace and preheating the machine after being supplemented with heat by the electric auxiliary heater 11.

[0040] Both the molten salt heater and the flash evaporator need to be designed and calculated in detail according to the flow characteristics of the molten salt side and the steam-water side, and arranged at a suitable location near the unit.

[0041] In some embodiments, the gas-steam combined cycle unit includes a gas turbine 1 , a waste heat boiler 2 , a steam turbine 3 , a generator 4 , a condenser 5 , a cooling tower 6 , a feed water pump 7 and a chimney 8 .

[0042] The gas turbine, steam turbine and generator are coaxially arranged, the waste heat boiler 2 is connected to one end of the gas turbine 1, the other end of the gas turbine 1 is connected to the steam turbine 3, the steam turbine 3 is connected to the generator, the exhaust gas of the steam turbine 3 is connected to the condenser 5, the condenser 5 is connected to the cooling tower 6, the condenser 5 is connected to the waste heat boiler 2 through the feed water pump 7, and the chimney 8 is connected to the waste heat boiler 2.

[0043] In some embodiments, the cold start system of the renewable energy is connected in parallel with the boiler start system through the unit preheating circulation pipeline.

[0044] The boiler starting system is a starting system of the gas-steam combined cycle system, including a first starting boiler and a second starting boiler. The first starting boiler is connected to the steam turbine 3 through the unit preheating circulation pipeline, and the second starting boiler is connected to the outlet of the condenser 5.

[0045] When the unit is started, the gas turbine is ignited, and at the same time, part of the condenser feed water is regulated to start the boiler, prepare startup steam, and preheat the waste heat boiler and steam turbine. Due to the thermal stress limitations of the steam-water system pipelines, the preheating rate of the waste heat boiler and steam turbine should not be too fast. After the unit is loaded, it operates in a single-cycle low-load condition for a long time; until the pressure and temperature of each level of the steam-water system pipelines meet the standards, the unit gradually increases the load to full load conditions.

[0046] In some embodiments, the unit preheating cycle pipeline is provided with a first heat release regulating valve group V1 and a second heat release regulating valve group V2; The first heat release regulating valve group V1 includes three valves, two of which are respectively arranged at the outlet of the first startup boiler and the outlet pipeline of the waste heat boiler 2, and the other valve is arranged at the inlet of the steam turbine.

[0047] The second heat release regulating valve group V2 includes three valves, one valve is set at the outlet of the condenser, one valve is set at the inlet of the warm-up pump 9 , and the other is set at the inlet of the water pump 7 .

[0048] The working principle of the above-mentioned cold start system of renewable energy is described in detail below.

[0049] The cold start system of the renewable energy provided by the present invention is connected in parallel with the boiler start system of the gas-steam combined cycle system through the unit preheating circulation pipeline, and two groups of heat release regulating valve groups V1 and V2 are arranged at the connecting position for coordinated regulation.

[0050] When the heat storage of the cold start system of the renewable energy cannot meet the starting conditions of the gas-steam combined cycle system, the cold start system of the renewable energy stops working, and the combined cycle unit is cold started using the boiler starting system by controlling the heat intake control valve group and the heat release control valve group.

[0051] When the heat storage of the cold start system of the renewable energy is sufficient and suitable for operation, before the cold start of the combined cycle unit, the cold start system of the renewable energy releases heat in a timely manner, and the flash evaporator heats the feed water in the preheating circulation pipeline of the unit to prepare starting steam. The steam enters the waste heat boiler and steam turbine through the preheating circulation pipeline of the unit for preheating, realizing the transition from cold start to warm start of the unit, shortening the cold start time of the combined cycle unit.

[0052] Another aspect of the present invention provides a gas-steam combined cycle system, comprising the above-mentioned renewable energy cold start system.

[0053] The present invention provides a cold start system for renewable energy, including a renewable energy heat collection and heat extraction device and a molten salt heat storage and flash evaporation device; the renewable energy heat collection and heat extraction device includes a hot water storage tank, a water pump, a molten salt heater, a geothermal injection well, a geothermal production well, a solar collector and other equipment. The device combines solar heat collection technology and deep geothermal heat extraction technology to use renewable energy to heat the molten salt heat storage medium. The two heating methods are coordinated and regulated by two groups of heat extraction control valve groups. When the weather is clear and the sunlight is sufficient, the molten salt heat storage medium is heated by solar heat collection; when the weather is cloudy and rainy and the sunlight is weak, the molten salt heat storage medium is heated by deep geothermal energy.

[0054] The molten salt heat storage flash device includes a warm-up pump, a flash evaporator, an electric auxiliary heater, a warm-up valve, a low-temperature molten salt tank, a molten salt heater, a high-temperature molten salt tank, a molten salt pump, a molten salt valve and other equipment. The device uses molten salt to store and release heat in a timely manner, flash evaporates part of the condenser hot well feed water, and prepares startup steam. During operation, the low-temperature molten salt in the low-temperature molten salt tank is heated and heated by the molten salt heater to form a high-temperature molten salt that enters the high-temperature molten salt tank for heat storage. The high-temperature molten salt is regulated by the molten salt pump and the molten salt valve to enter the flash evaporator. It is used as a heat source to flash evaporate part of the condenser hot well feed water to prepare steam, and then returns to the low-temperature molten salt tank to form a cycle. The prepared startup steam is supplied to the steam-water system for preheating the preheating boiler and preheating the steam turbine after being supplemented by the electric auxiliary heater.

[0055] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A cold start system for renewable energy, characterized in that: It includes a renewable energy heat collection and extraction device and a molten salt heat storage and flash evaporation device; The renewable energy heat collection and heat extraction device comprises a molten salt heater and a renewable energy thermal energy device, and the working medium circulation pipeline on the heat absorption side of the molten salt heater is connected to the renewable energy thermal energy device; The molten salt heat storage flash evaporation device comprises a low-temperature molten salt tank, a high-temperature molten salt tank and a flash evaporator arranged on a working medium circulation pipeline on the heat release side of the molten salt heater; The steam-water side of the flash evaporator is connected to the waste heat boiler and the steam turbine of the gas-steam combined cycle unit through the unit preheating circulation pipeline.

2. A cold start system of renewable energy according to claim 1, characterized in that: The renewable energy thermal energy device includes at least one heat source selected from the group consisting of a solar energy device, a geothermal energy device, boiler waste heat, high-temperature flue gas from a combined cycle unit, and auxiliary steam from an adjacent combined cycle unit.

3. A cold start system of renewable energy according to claim 2, characterized in that: The working fluid pipelines of the solar energy device and the geothermal energy device are connected in parallel and are connected in series with the working fluid circulation pipeline on the heat absorption side of the molten salt heater.

4. A cold start system of renewable energy according to claim 3, characterized in that: A hot water storage tank is arranged on the working medium circulation pipeline on the heat absorption side of the molten salt heater. The hot water storage tank is connected to the heat outlet on the heat absorption side of the molten salt heater through a water pump. The heat absorption side outlet of the molten salt heater is connected to the hot water storage tank through a renewable energy thermal energy device.

5. The cold start system of renewable energy according to claim 1, characterized in that: A second heat-taking regulating valve group V4 is arranged between the working medium outlet of the renewable energy thermal energy device and the working medium circulation pipeline on the heat absorption side, and a first heat-taking regulating valve group V3 is arranged at the outlet of the working medium circulation pipeline. The two heat-taking regulating valve groups are used to control the working state of the renewable energy heat collection and heat extraction device.

6. A cold start system of renewable energy according to claim 1, characterized in that: The low-temperature molten salt tank is connected to the inlet of the molten salt heater on the heat release side, the outlet of the molten salt heater on the heat release side is connected to the molten salt pump through the high-temperature molten salt tank, the molten salt pump is connected to the working fluid inlet of the flash evaporator, and the working fluid outlet of the flash evaporator is connected to the low-temperature molten salt tank.

7. A cold start system of renewable energy according to claim 1, characterized in that: A molten salt valve is provided on the circulation pipeline on the heat release side of the molten salt heater to control the working state of the molten salt heat storage flash evaporation device.

8. A cold start system of renewable energy according to claim 1, characterized in that: The outlet of the steam-water side of the flash evaporator is connected to an electric auxiliary heater, which is connected to a waste heat boiler and a steam turbine in sequence through pipelines, and the steam turbine is connected to the inlet of the steam-water side of the flash evaporator through a warm-up pump.

9. A cold start system of renewable energy according to claim 1, characterized in that: Also included is the boiler start-up system; The boiler starting system is connected in parallel with the cold starting system of the renewable energy through the unit preheating circulation pipeline.

10. A gas-steam combined cycle system, characterized in that: A cold start system for renewable energy comprising the renewable energy described in any one of claims 1-9.

Images