Green electricity system for reducing carbon emission intensity of coal power and method for determining capacity of the system

Abstract

The application discloses a green electricity storage and heat utilization system and a capacity determination method for reducing carbon emission intensity of coal power, takes molten salt as a medium, converts surplus renewable energy power such as wind power and light power into heat energy and stores the heat energy in the molten salt, and helps new energy power consumption. In the energy release stage, the heat energy of the molten salt is converted into high-parameter steam, enters the inlet of a high-pressure cylinder of a steam turbine or the inlet of a certain stage, and generates power through work, thereby reducing the amount of new steam of a coal-fired boiler. The carbon reduction effect is positively correlated with the proportion of high-grade steam, and the system has the advantages of simplicity, safety and reliability. The application provides an operation method of the coupled system, and takes the annual carbon reduction proportion as a target, so that the system can effectively help high-proportion new energy power consumption, promote carbon reduction of a coal power unit, help coal power enterprises in transformation and high-quality development, and has a wide application prospect.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of coal power carbon reduction and operation flexibility improvement, and relates to a green power storage and heat system for reducing carbon emission intensity of coal power and a capacity determination method. BACKGROUND

[0002] With the gradual advancement of energy transformation, the positioning and function of coal power units in the power industry and industrial system are gradually changing. In the early stage, the main body of power is mainly used, accompanied by rapid development of wind and light new energy power. The coal power units with large installed capacity and dense geographical distribution are gradually transformed into the main body of adjustment, not only helping the large-scale development and high proportion of renewable energy such as wind and light with strong time-varying characteristics, but also gradually forming a city solid waste disposal platform and centralized energy supply (life heating, industrial steam, etc.) platform with coal power as the core. With the frequent occurrence of extreme weather (high temperature, extreme cold, gale, heavy rain, etc.), the output of new energy decreases rapidly, and coal power is needed to quickly peak. At the same time, low carbonization has become the main demand of coal power in recent years. Low carbon, flexibility, high efficiency, cleanliness, intelligence and reliability are the main "performance labels" of coal power in the new era.

[0003] However, the coal power unit thermal cycle based on the Rankine cycle is the main way to improve cycle efficiency and reduce power generation coal consumption (carbon emission intensity) by improving initial parameters and reducing exhaust end parameters. Due to the limitation of high-temperature materials, the highest level of initial parameters is 31MPa, 620-630℃; due to the limitation of cold source conditions, the best quality condition is seawater cooling, and the back pressure of the steam turbine is about 2kPa. This is the "ceiling" of coal power, and the rated load power consumption is about 260g / kWh, which is equivalent to carbon emission intensity of 749g / kWh. It can be seen that there is little room for further reducing power consumption and carbon emission intensity by focusing on coal power steam water thermal cycle.

[0004] The electricity generated by wind and light, etc. is called green electricity. Green electricity is applied to heat molten salt storage system to convert green electricity into heat energy and store it in molten salt. In the energy release stage, high-temperature molten salt is used to heat coal-fired unit feedwater to generate high-parameter steam, which enters the steam turbine to do work and generate electricity, that is, to complete the heating and storage, which is called heating and storage for short. Some studies have proposed that zero-carbon fuels such as green hydrogen, green ammonia and biomass can be mixed in the boiler to reduce coal consumption while maintaining the power of coal-fired power generation, which is equivalent to reducing the coal consumption and carbon emission intensity of power supply. The key to this technical idea is that the hydrogen, ammonia and other fuels mixed in must be zero-carbon (i.e. green hydrogen, green ammonia, etc.) in order to achieve true carbon reduction. From the whole process chain, hydrogen, ammonia and other fuels are produced by zero-carbon renewable electricity such as wind and light, which has zero-carbon properties. Through the adaptability modification of the coal-fired boiler combustion system, a certain proportion of zero-carbon green hydrogen, green ammonia and other fuels is mixed in to reduce carbon emissions. The carbon reduction effect is positively correlated with the proportion of zero-carbon fuel mixed in, but there are problems such as complex process flow and large investment (for example, green hydrogen, which requires the addition of a hydrogen production system, a hydrogen storage system, a hydrogen transportation system, and the adaptability modification of the boiler combustion system; in addition, hydrogen is explosive and needs to be controlled as a major hazard source). SUMMARY

[0005] The purpose of the present application is to solve the problems in the prior art and provide a green electricity storage and heat system for reducing the carbon emission intensity of coal-fired power and a capacity determination method. The present application provides a coupling system operation method and a capacity determination method for a green electricity storage and heat system with an annual carbon reduction ratio as the target.

[0006] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0007] In a first aspect, the present application provides a green electricity storage and heat system for reducing the carbon emission intensity of coal-fired power, comprising:

[0008] The green electricity storage and heat system comprises a high-temperature molten salt storage tank and a low-temperature molten salt storage tank; the outlet of the high-temperature molten salt storage tank is connected to the hot side inlet of a molten salt-water heat exchanger, the hot side outlet of the molten salt-water heat exchanger is connected to the inlet of the low-temperature molten salt storage tank; the outlet of the low-temperature molten salt storage tank is connected to the cold side inlet of a molten salt electric heater, the cold side outlet of the molten salt electric heater is connected to the inlet of the high-temperature molten salt storage tank; the cold side of the molten salt-water heat exchanger is connected to a coal-fired steam-water thermal cycle system, and the hot side of the molten salt electric heater is connected to new energy power and / or coal-fired unit power;

[0009] The coal-fired steam-water thermal cycle system comprises a coal-fired boiler, a high-pressure cylinder and a low-pressure cylinder; the exhaust steam of the coal-fired boiler is connected to the steam inlet of the high-pressure cylinder, the exhaust steam of the high-pressure cylinder is connected to the low-pressure cylinder, and the exhaust steam of the low-pressure cylinder is returned to the coal-fired boiler after being heated by a heating assembly and a molten salt-water heat exchanger.

[0010] In a second aspect, the application provides a capacity determination method, comprising the following steps:

[0011] According to the carbon reduction target, the boundary constraint of the green electricity-to-heat storage system is determined;

[0012] According to the boundary constraint, the steam generation load, annual operation time and single cycle heat storage time of the green electricity-to-heat storage system are calculated;

[0013] According to the steam generation load, annual operation time and single cycle heat storage time, the heat storage power and molten salt quantity of the green electricity-to-heat storage system are calculated.

[0014] Compared with the prior art, the application has the following beneficial effects:

[0015] The application uses molten salt as a medium to convert excess renewable energy power such as wind and light into heat energy stored in molten salt, helping to consume new energy power. In the energy release stage, the heat energy of the molten salt is converted into high-parameter steam, which enters the inlet of the high-pressure cylinder of the steam turbine or a certain stage, does work and generates electricity, reduces the amount of new steam of the coal-fired boiler, and is equivalent to reducing the amount of coal consumption of the boiler. The carbon reduction effect and the proportion of high-grade steam incorporated are positively correlated, and the system has the advantages of simplicity, safety and reliability. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0017] Figure 1 The process flow diagram of the green electricity-to-heat storage system for reducing the carbon emission intensity of coal-fired power in the application.

[0018] Among them: 1-new energy power, 2-coal-fired power unit power, 3-molten salt electric heater, 4-high temperature molten salt storage tank, 5-high temperature molten salt pump, 6-molten salt-water heat exchanger, 7-low temperature molten salt tank, 8-low temperature molten salt pump, 9-coal-fired boiler, 10-high and medium pressure cylinder, 11-low pressure cylinder, 12-condenser, 13- condensate pump, 14-low pressure heater group, 15-deaerator, 16-prepump, 17-feedwater pump, 18-high pressure heater group, 19-first feedwater variable frequency booster pump, 20-first valve group, 21-second valve group, 22-second feedwater variable frequency booster pump. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. The components of the embodiments of the present application described and shown in the drawings can be arranged and designed in various different configurations.

[0020] Therefore, the detailed description of the embodiments of the present application provided below in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without making creative efforts fall within the scope of protection of the present application.

[0021] It should be noted that: similar reference numbers and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0022] In the description of the embodiments of the present application, it should be noted that, if the orientation or position relationship indicated by the terms "upper", "lower", "horizontal", "inner" and the like is based on the orientation or position relationship shown in the drawings, or is the orientation or position relationship when the product of the present application is usually placed, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, therefore, it cannot be understood as a limitation on the present application. In addition, the terms "first", "second" and the like are only used for differentiation in description, and cannot be understood as indicating or implying relative importance.

[0023] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly inclined. For example, "horizontal" only means that its direction is relatively more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0024] In the description of the embodiments of the present application, it should also be noted that, unless otherwise explicitly specified and limited, if the terms "set", "mount", "connected", "connected" appear, they should be understood in a broad sense, for example, can be fixedly connected, can be detachably connected, or integrally connected; can be mechanically connected, can be electrically connected; can be directly connected, can be indirectly connected through an intermediate medium, can be the communication inside two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0025] The present application will be described in further detail below with reference to the drawings:

[0026] Referring toFigure 1 The embodiment of the present application discloses a green electricity storage heat system for reducing carbon emission intensity of coal power, which comprises a green electricity storage heat system and a coal power water-steam heat cycle system.

[0027] The green electricity storage heat system comprises a high-temperature molten salt storage tank 4 and a low-temperature molten salt storage tank 7; the outlet of the high-temperature molten salt storage tank 4 is connected to the hot side inlet of a molten salt-water heat exchanger 6, the hot side outlet of the molten salt-water heat exchanger 6 is connected to the inlet of the low-temperature molten salt storage tank 7; the outlet of the low-temperature molten salt storage tank 7 is connected to the cold side inlet of a molten salt electric heater 3, the cold side outlet of the molten salt electric heater 3 is connected to the inlet of the high-temperature molten salt storage tank 4; the cold side of the molten salt-water heat exchanger 6 is connected to the coal power water-steam heat cycle system, the hot side of the molten salt electric heater 3 is connected to new energy power 1 and / or coal power unit power 2; a high-temperature molten salt pump 5 is arranged on the pipeline between the high-temperature molten salt storage tank 4 and the molten salt-water heat exchanger 6; a low-temperature molten salt pump 8 is arranged on the pipeline between the low-temperature molten salt storage tank 7 and the molten salt electric heater 3.

[0028] The coal power water-steam heat cycle system comprises a coal-fired boiler 9, a high-medium pressure cylinder 10 and a low pressure cylinder 11; the exhaust steam of the coal-fired boiler 9 is connected to the steam inlet of the high-medium pressure cylinder 10, the exhaust steam of the high-medium pressure cylinder 10 is connected to the low pressure cylinder 11, and the exhaust steam of the low pressure cylinder 11 is returned to the coal-fired boiler 9 after being heated by a heating assembly and the molten salt-water heat exchanger 6.

[0029] The main steam outlet of the coal-fired boiler 9 is connected to the high pressure cylinder steam inlet of the high-medium pressure cylinder 10, the exhaust steam outlet of the high pressure cylinder is connected to the reheated steam inlet of the coal-fired boiler 9 through a cold reheat pipe, the reheated steam outlet of the coal-fired boiler 9 is connected to the medium pressure cylinder steam inlet of the high-medium pressure cylinder 10, the exhaust steam outlet of the medium pressure cylinder is connected to the steam inlet of the low pressure cylinder 11 through a medium pressure connecting pipe, and the exhaust steam of the low pressure cylinder 11 is returned to the coal-fired boiler 9 after being heated and pressurized by the pressurizing heating assembly and the molten salt-water heat exchanger 6, so as to complete the water-steam heat cycle.

[0030] The pressurizing heating assembly comprises a condenser 12, a condensate pump 13, a low pressure heater group 14, a deaerator 15, a pre-pump 16, a feed water pump 17 and a high pressure heater group 18 which are sequentially connected, the inlet of the condenser 12 is connected to the exhaust steam outlet of the low pressure cylinder 11, and the outlet of the high pressure heater group 18 is connected to the steam inlet of the coal-fired boiler 9; the outlet of the pre-pump 16 is further connected to a first feed water variable frequency booster pump 19 through a first valve group 20, and the outlet of the high pressure heater group 18 is further connected to a second feed water variable frequency booster pump 22 through a second valve group 21; the outlets of the first feed water variable frequency booster pump 19 and the second feed water variable frequency booster pump 22 are both connected to the cold side inlet of the molten salt-water heat exchanger 6; the cold side outlet of the molten salt-water heat exchanger 6 is divided into three paths, the first path is connected to the high pressure cylinder steam supplementing port, the second path is connected to the high pressure cylinder inlet, and the third path is used as an industrial steam supply outlet.

[0031] Embodiment

[0032] To clearly describe the implementation process of a green electricity system for reducing carbon emission intensity of coal-fired power plants and a capacity determination method proposed in this application, a 1000 MW ultra-supercritical grade, high-pressure cylinder fifth stage after configuration of steam supplement valve, pure condensing unit without external heat supply is taken as an example. The operation process of this example is as follows. In addition, regarding the selection of molten salt medium, the three molten salt formulations specified in GB / T36376-2018 are Hitec salt, type I ternary salt, and type II low melting point salt, with working temperature ranges of 260-560℃, 190-400℃, and 190-400℃, respectively. At present, Hitec salt can be selected, and the steam production parameters of the green electricity heat production system can be benchmarked with the ultra-supercritical high-pressure cylinder steam supplement parameters. After the successful development of high-parameter, wide-temperature-range, and national standard-compliant molten salt, the steam production parameters of the green electricity heat production system can be benchmarked with the high-pressure cylinder inlet parameters.

[0033] Reference: High parameters, large capacity, full load, high efficiency, high flexibility, and intelligence are the development direction of new coal-fired power plants. The main steam pressure of a once-reheated unit is 28 MPa, and the temperature is 600℃. The main steam pressure of a twice-reheated unit is 32 MPa, and the temperature is 620℃. The steam supplement position is generally after the fifth stage of the high-pressure cylinder (1000 MW unit) or after the sixth stage (600 MW unit). For example, a 25 MPa / 600℃ / 600℃ million ultra-supercritical once-reheated unit has a rated working condition steam supplement parameter of 16 MPa, 525℃, and 280t / h. A 25 MPa / 600℃ / 600℃ million ultra-supercritical once-reheated unit has a rated working condition steam supplement parameter of 16 MPa, 527℃, and 160t / h. A 31 MPa / 605℃ / 622 / 620℃ ultra-supercritical twice-reheated unit has a rated working condition steam supplement parameter that is basically the same as that of a once-reheated unit.

[0034] Figure 1 is a process system flow diagram of a green electricity system for reducing carbon emission intensity of coal-fired power plants proposed in this application. Among them, new energy power 1, coal-fired power unit power 2, molten salt electric heater 3, high-temperature molten salt storage tank 4, high-temperature molten salt pump 5, molten salt-water heat exchanger 6, low-temperature molten salt tank 7, and low-temperature molten salt pump 8 constitute a green electricity heat storage system, coal-fired boiler 9, high-pressure cylinder 10, low-pressure cylinder 11, condenser 12, condensate pump 13, low-pressure heater group 14, deaerator 15, pre-pump 16, feedwater pump 17, and high-pressure heater group 18 are the coal-fired steam-water thermal cycle system, and the green electricity heat storage system and the coal-fired steam-water thermal cycle system are coupled through the first feedwater variable frequency booster pump 19, the first valve group 20, the second valve group 21, and the second feedwater variable frequency booster pump 22.

[0035] The working principle of the present application is as follows:

[0036] (1) Coal-fired steam-water thermal cycle system operation alone. The main steam generated by the coal-fired boiler 9 enters the high-pressure cylinder inlet of the high-medium-pressure cylinder 10 to do work, and the exhaust steam enters the medium-pressure cylinder inlet of the high-medium-pressure cylinder 10 after being heated twice by the coal-fired boiler 9 and then enters the low-pressure cylinder 11 through the medium-low pressure communication pipe to do work and generate electricity. The exhaust steam enters the condenser 12 to be condensed into condensate water, which is then pressurized by the condensate pump 13, and then flows through the low-pressure heater group 14, the deaerator 15, the pre-pump 16, the feedwater pump 17, and the high-pressure heater 18 group in turn before entering the boiler, completing the steam-water thermal cycle.

[0037] (2) Green electricity storage heat system heat storage operation. During the peak period of wind and solar power generation, part of the excess wind and solar power 1 is used to heat the molten salt in the electric heater 3. The cold salt (temperature about 280℃) is driven by the low-temperature molten salt pump 8 from the low-temperature molten salt storage tank 7, enters the electric heater 3, is heated by electricity (temperature about 540℃), and then enters the high-temperature molten salt storage tank 4 for storage. Generally, the cold salt in the low-temperature molten salt storage tank 7 is emptied, and the high-temperature molten salt storage tank 4 is full, which is called a complete heat storage process. During the heat release stage, generally during the non-peak period of new energy output, the high-temperature molten salt in the high-temperature molten salt storage tank 4 is driven by the high-temperature molten salt pump 5 into the molten salt-water heat exchanger 6, and the outlet water of the pre-pump 16 and the high-pressure heater 18 group is pressurized by the feedwater variable frequency booster pump 19 and then enters the molten salt-water heat exchanger 6 to absorb the heat of the high-temperature molten salt and vaporize in the form of high-parameter (16MPa, 525℃) steam into the steam turbine high-pressure cylinder to supplement steam. Under the condition of maintaining the output power of the steam turbine unchanged, the amount of steam at the outlet of the coal-fired boiler 9 is reduced, that is, the coal consumption of the coal-fired power unit is reduced. The high-temperature molten salt is released in the molten salt-water heat exchanger 6 and then stored in the low-temperature molten salt storage tank 7 as cold salt, waiting for the next cycle.

[0038] (3) Green electricity storage heat system assisting coal-fired power unit peak shaving and frequency modulation operation. When the coal-fired power unit has a deep peak shaving demand, the green electricity storage heat system enters the heat storage mode and consumes the power generation of the coal-fired power unit to heat the molten salt. When the coal-fired power unit has a demand for increasing the load change rate, the molten salt electric heater 3 of the green electricity storage heat system operates at 20% power, and the power of the electric heater is quickly increased or decreased to assist the coal-fired power unit in increasing the load change rate.

[0039] The embodiment of the present application also discloses a capacity determination method of the green electricity storage heat system, which is targeted at the annual carbon reduction ratio. The main idea of determining the capacity of the green electricity storage heat system is: based on the unchanged annual power generation of the coal-fired power unit, the steam generation power of the green electricity storage heat system is determined, and then the annual operation time, the single-cycle heat storage time, the molten salt storage capacity, and the molten salt storage tank volume of the green electricity storage heat system are calculated in turn ， to obtain the molten salt storage capacity. According to the above, the process system flow design and equipment selection of the green electricity storage heat system can be carried out. The specific capacity determination method comprises the following steps:

[0040] Step 1: According to the carbon reduction target, determine the boundary constraints of the green electricity-to-heat storage system.

[0041] The nameplate output of the coal-fired unit is , unit: MW. The annual power generation of the coal-fired unit is , unit: kWh. The annual operating hours , unit: hours. The annual weighted average coal consumption is , unit: g / kWh. The total annual standard coal consumption is calculated as , unit: tons. The total annual carbon dioxide emissions are converted to , unit: tons.

[0042] The annual power generation of the coal-fired unit is constant, and the annual carbon reduction ratio is , then the annual steam production of the green electricity-to-heat storage system is .

[0043] Step 2: Calculate the steam production load of the green electricity-to-heat storage system

[0044] The unit is in 100% 、 90% 、 80% three output conditions, using the "with and without comparison method", without incorporating the heat of the green electricity-to-heat storage system, through the field operation system, the boiler main steam flow of the three output conditions is obtained , and , unit: t / h.

[0045] When incorporating the heat of the green electricity-to-heat storage system, the power generation of the coal-fired unit remains unchanged, still in 100% 、 90% 、 80% three output conditions, when the boiler main steam flow of the three output conditions reaches , and , respectively, it is determined that the carbon reduction ratio of the three output conditions reaches the target . Thus, the steam production load of the green electricity-to-heat storage system is calculated as as follows, unit: t / h.

[0046]

[0047] In the formula, , and H1, H2, H3 are the enthalpy values of the main steam of the boiler under three output conditions, kJ / kg; , and are the enthalpy values of the condenser outlet water under three output conditions, kJ / kg; , and are the enthalpy values of the feed water under three output conditions, kJ / kg. is the enthalpy value of the steam generated by the green electricity-based thermal storage system, kJ / kg.

[0048] At this time, the steam generation load of the green electricity-based thermal storage system can be calculated as follows: The power generated by the green electricity-based thermal storage system is , and the unit is MW.

[0049]

[0050] Step 3, calculate the annual operation time of the green electricity-based thermal storage system

[0051] According to the carbon reduction ratio , the annual power generation of the green electricity-based thermal storage system in the coal-fired power plant is , and the unit is kWh.

[0052] The annual operation time of the green electricity-based thermal storage system is calculated as follows .

[0053]

[0054] Step 4, calculate the single-cycle heat storage time of the green electricity-based thermal storage system

[0055] According to the time-varying characteristics of new energy output in the region where the coal-fired power plant is located, the daily cycle number of the green electricity-based thermal storage system is determined . In new energy-rich regions such as the Three Norths or coastal wind energy-rich regions, take 2; in other regions, take 1.

[0056] Note: Cycle number 1 refers to the completion of one heat storage and heat release cycle of the green electricity-based thermal storage system.

[0057] The single-cycle heat storage time of the green electricity-based thermal storage system is calculated as follows .

[0058]

[0059] In the formula, is the annual operation days of the coal-fired power plant. Point to the upper integer.

[0060] Step 5, calculate the heat storage power of the green electricity storage heat system and the amount of molten salt

[0061] Heat storage power is equal to the heat release power of the molten salt in the molten salt-water heat exchanger 6, and is calculated as follows. The unit is MW.

[0062]

[0063] It is also equal to the heat absorption power of the molten salt in the molten salt electric heater, and the circulating flow rate of the molten salt is calculated as follows , and the unit is t / h.

[0064]

[0065] In the formula, and are the enthalpy values of the high-temperature molten salt and the low-temperature molten salt, respectively, kJ / kg.

[0066] Molten salt circulating flow rate times the heat storage duration of a single cycle , and multiplied by the allowance coefficient of 10%, the heat storage capacity of the green electricity storage heat system is calculated as follows, and the unit is tons.

[0067]

[0068] The present application provides a coupling system operation method, and proposes a green electricity storage heat system capacity determination method with the target of annual carbon reduction ratio. The present application can effectively promote high proportion of new energy power consumption, and can also promote carbon reduction of coal-fired units, help coal-fired enterprises to transform and develop in high quality, and has wide application prospect.

[0069] The above is only a preferred embodiment of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various changes and variations. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for determining the capacity of a green electricity generation, storage, and heat utilization system that reduces the carbon emission intensity of coal-fired power plants, characterized in that: The green electricity generation, storage, and heat utilization system for reducing the carbon emission intensity of coal-fired power plants includes: A green electricity thermal energy storage system includes a high-temperature molten salt storage tank (4) and a low-temperature molten salt storage tank (7); the outlet of the high-temperature molten salt storage tank (4) is connected to the hot side inlet of a molten salt-water heat exchanger (6), and the hot side outlet of the molten salt-water heat exchanger (6) is connected to the inlet of the low-temperature molten salt storage tank (7); the outlet of the low-temperature molten salt storage tank (7) is connected to the cold side inlet of a molten salt electric heater (3), and the cold side outlet of the molten salt electric heater (3) is connected to the inlet of the high-temperature molten salt storage tank (4); the cold side of the molten salt-water heat exchanger (6) is connected to a coal-fired power steam-water thermal circulation system, and the hot side of the molten salt electric heater (3) is connected to new energy power (1) and / or coal-fired power unit power (2). The coal-fired power steam-water thermal circulation system includes a coal-fired boiler (9), an intermediate-pressure cylinder (10), and a low-pressure cylinder (11). The exhaust steam of the coal-fired boiler (9) is connected to the inlet steam of the intermediate-pressure cylinder (10), and the exhaust steam of the intermediate-pressure cylinder (10) is connected to the low-pressure cylinder (11). The exhaust steam of the low-pressure cylinder (11) is heated by heating components and a molten salt-water heat exchanger (6) and then returned to the coal-fired boiler (9). The capacity determination method includes the following steps: Based on carbon reduction targets, the boundary constraints of green energy generation, storage, and heat utilization systems are determined; the determination of the boundary constraints of green energy generation, storage, and heat utilization systems includes: The annual steam production of the green energy generation, storage, and heat utilization system, and the power generation generated by the steam turbine, are as follows: in, This refers to the annual power generation of coal-fired power units. The percentage of carbon reduction per year; Calculate the steam generation load, annual operating time, and single-cycle thermal storage duration of the green electricity generation, storage, and heat utilization system based on boundary constraints. The steam production load is calculated using the following method: The unit is at 100% 、 90% 、 80% Using a "comparison method with and without" for the three output conditions, the main steam flow rate of the boiler under the three output conditions was determined through on-site operation of the system without the addition of heat from the green electricity generation and storage system. , and The unit is t / h; When heat from a green energy storage and utilization system is incorporated, the power generation capacity of coal-fired power units remains at 100%. 、 90% 、 80% With the three output conditions remaining unchanged, the main steam flow rate of the boiler under the three output conditions respectively reaches... , and At that time, it was determined that the carbon reduction ratio of these three output conditions reached the annual carbon reduction ratio of the guiding target. Therefore, the steam production load of the green electricity generation, storage, and heat utilization system can be calculated. as follows: In the formula, , and These are the enthalpy values ​​of the boiler main steam under three different output conditions; , and These are the enthalpy values ​​of condenser outlet water under three different output conditions; , and These are the feedwater enthalpy values ​​under three different power output conditions; It is the enthalpy value of steam produced by the green electricity generation, storage, and heat utilization system; At this point, the steam production load of the green electricity generation, storage, and heat utilization system can be calculated. Power generation capacity: in, Steam load for green electricity generation, storage, and heat utilization systems Power generation capacity, Contribute to the nameplates of coal-fired power units; The thermal storage power and molten salt quantity of the green electricity generation and storage thermal system are calculated based on the steam production load, annual operating time, and single cycle thermal storage duration.

2. The capacity determination method according to claim 1, characterized in that, The calculation method for the annual runtime is as follows: in, Annual operating time for green electricity generation, storage, and heat utilization systems.

3. The capacity determination method according to claim 2, characterized in that, The calculation method for the single-cycle thermal storage duration is as follows: in, The duration of thermal storage in a single cycle of a green electricity generation, storage, and heat utilization system. Point to round up. This refers to the number of operating days per year for coal-fired power units. The daily cycle number of the green electricity generation, storage, and heat utilization system.

4. The capacity determination method according to claim 3, characterized in that, The calculation methods for the thermal storage power and molten salt quantity of the green electricity generation and storage thermal system are as follows: The thermal storage power is as follows: in, For thermal storage power; The circulation flow is as follows: in, For circulating flow, and These are the enthalpy values ​​of high-temperature molten salt and low-temperature molten salt, respectively. The molten salt content for green electricity generation, storage, and heat utilization systems is as follows: in, The amount of molten salt for the green electricity generation, storage, and heat system.

5. The capacity determination method according to claim 1, characterized in that, A high-temperature molten salt pump (5) is installed on the pipeline between the high-temperature molten salt storage tank (4) and the molten salt-water heat exchanger (6); a low-temperature molten salt pump (8) is installed on the pipeline between the low-temperature molten salt storage tank (7) and the molten salt electric heater (3).

6. The capacity determination method according to claim 1, characterized in that, The main steam outlet of the coal-fired boiler (9) is connected to the high-pressure cylinder inlet of the high-pressure cylinder (10). The exhaust port of the high-pressure cylinder is connected to the reheat steam inlet of the coal-fired boiler (9) through the cold reheat main pipe. The reheat steam outlet of the coal-fired boiler (9) is connected to the medium-pressure cylinder inlet of the high-pressure cylinder (10). The exhaust port of the medium-pressure cylinder is connected to the inlet of the low-pressure cylinder (11) through the medium-low pressure connecting pipe. The exhaust steam of the low-pressure cylinder (11) is heated and pressurized by the pressurization heating component and the molten salt-water heat exchanger (6) and then returned to the coal-fired boiler (9) to complete the steam-water thermal cycle.

7. The capacity determination method according to claim 6, characterized in that, The pressurized heating assembly includes a condenser (12), a condensate pump (13), a low-pressure heater group (14), a deaerator (15), a pre-pump (16), a feed water pump (17), and a high-pressure heater group (18) connected in sequence. The inlet of the condenser (12) is connected to the exhaust port of the low-pressure cylinder (11), and the outlet of the high-pressure heater group (18) is connected to the steam inlet of the coal-fired boiler (9). The outlet of the pre-pump (16) is also connected to the first feedwater variable frequency booster pump (19) through the first valve group (20), and the outlet of the high-pressure heater group (18) is also connected to the second feedwater variable frequency booster pump (22) through the second valve group (21); the outlets of the first feedwater variable frequency booster pump (19) and the second feedwater variable frequency booster pump (22) are both connected to the cold side inlet of the molten salt-water heat exchanger (6); the cold side outlet of the molten salt-water heat exchanger (6) is divided into three paths, the first path is connected to the high-pressure cylinder steam injection port, the second path is connected to the high-pressure cylinder inlet, and the third path is used as industrial steam supply output.

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