Solar energy-gas combined cycle power generation systemTechnical Field
The invention relates to the technical field of power generation equipment, in particular to a solar energy-fuel gas combined cycle power generation system.
Background
The solar energy is inexhaustible clean energy, and has very wide development prospect. Solar thermal power generation has been developed to varying degrees around the world, but its large-scale commercial application has been hampered by the discontinuities and instabilities of solar energy. The gas-steam combined cycle power generation is a clean energy power generation mode, has small environmental pollution, short construction period and reliable and stable operation, and the core equipment of the gas-steam combined cycle is a gas turbine which is very stable in operation but has larger performance influenced by environmental factors. In order to improve the heat efficiency of the gas-steam combined cycle, the exhaust gas temperature of the waste heat boiler can be reduced as much as possible in a certain range. The two energy utilization forms have certain defects, and the complementary power generation form can effectively reduce the influence of high-temperature weather on the output of the unit and can also enable the unit to continuously and stably generate power.
The utilization of single energy varieties is subject to multiparty elbow pulling, so that in the future development process, the construction of a comprehensive energy system for organically integrating and complementarily integrating multiple energy sources is becoming a great trend.
Disclosure of Invention
The invention aims to provide a solar energy-fuel gas combined cycle power generation system, which is an energy complementary power generation mode, and the operation performance of the system is improved by replacing an evaporator of a waste heat boiler with a solar heat collection field and utilizing a boiler tail heater as a solar heat collection preheating mode, so that the heat exchange efficiency of the waste heat boiler and the continuous stability of solar power generation can be effectively improved.
In order to achieve the above purpose, the invention adopts the following technical scheme:
The solar energy-fuel gas combined cycle power generation system comprises a fuel gas-steam combined cycle power generation subsystem and a solar energy direct steam subsystem, wherein the two subsystems are connected through a pipeline;
The gas-steam combined cycle power generation subsystem comprises a gas turbine, a gas turbine generator, a waste heat boiler, a condenser, a steam turbine generator, a condensate pump and a high-pressure water supply pump;
The gas turbine compressor is used for absorbing air from the external atmosphere and compressing the air, the compressed air is mixed with fuel sprayed into a combustion chamber and then combusted, the generated high-temperature high-pressure flue gas enters a gas turbine to do work to drive the compressor to rotate and a gas turbine generator to generate power, the exhaust gas of the gas turbine enters a waste heat boiler, and is discharged to the atmosphere through a high-pressure superheater, a high-pressure evaporator, a high-pressure economizer, a low-pressure superheater, a low-pressure evaporator, a low-pressure economizer and a tail heat exchanger of the waste heat boiler respectively;
The solar direct steam subsystem comprises a heat collection preheating zone, a heat collection evaporation zone, a steam-water separator, a circulating pump and a heat collection superheating zone, wherein the water supply of the heat collection preheating zone is from a hot water heat exchanger outlet of the waste heat boiler, the water supply enters the heat collection evaporation zone after being preheated to reach saturation temperature, then the water is separated by the steam-water separator, the saturated water returns to the heat collection evaporation zone through the circulating pump to be continuously heated, the separated saturated steam generates low-pressure superheated steam after passing through the heat collection superheating zone, the low-pressure superheated steam generated by the solar direct steam system and the low-pressure superheated steam generated by the waste heat boiler are combined and enter a low-pressure superheated steam header, the low-pressure superheated steam is mixed with the high-pressure steam discharged by the high-pressure cylinder and then enters a low-pressure cylinder of the steam turbine to do work, and the condensed water is supplied to a low-pressure economizer and a hot water heat exchanger of the waste heat boiler after passing through a condensate pump, so that a thermodynamic cycle is achieved.
The invention is further improved in that the waste heat boiler is in double-pressure natural circulation, and low-pressure superheated steam generated in a low-pressure heat exchange area of the waste heat boiler is matched with superheated steam parameters generated in a solar direct steam system.
The invention further improves that the heat collection evaporation zone of the solar direct steam system is utilized to replace the low-pressure evaporator of the waste heat boiler.
The invention is further improved in that a hot water heater is additionally arranged at the tail part of the waste heat boiler to heat the water supply of the solar heat collection preheating zone, so that the heat exchange efficiency of the waste heat boiler is improved, and the investment of the solar heat collection preheating zone can be reduced.
The invention further improves that the solar direct steam system adopts a trough type heat collector, and the trough type solar heat collection field is divided into a preheating area, an evaporating area and a superheating area according to different heat collection temperatures.
The invention is further improved in that after the solar heat collection field is put into the low-pressure evaporator of the waste heat boiler, which is completely replaced or partially replaced, at the moment, the temperature of the flue gas is unchanged or partially reduced when the flue gas flows through the low-pressure evaporator, and the saturated temperature steam generated by the low-pressure evaporator and the solar heat collection field enters a low-pressure steam drum to be subjected to steam-water separation.
The invention is further improved in that the tail heater of the waste heat boiler heats the condensed water to 80-90 ℃, the temperature of the condensed water is close to the exhaust gas temperature of the waste heat boiler, and the condensed water is used as the water supply of the preheating zone of the solar heat collection field after the temperature is raised.
The invention is further improved in that the steam-water mixture in the evaporation area of the solar heat collection field passes through the steam-water separator, the separated water enters the superheat area of the heat collection field, and the separated water returns to the evaporation area through the circulating pump.
The invention is further improved in that the waste heat boiler is in a double-pressure, horizontal and natural circulation mode.
The invention has at least the following beneficial technical effects:
1. The solar energy and the fuel gas are complementary, under the condition of no energy storage, the solar energy and fuel gas combined type solar energy power generating system has the advantages that compared with single solar energy power generation, a power station can continuously operate, the stability of a unit is effectively improved, compared with single fuel gas power generation, the solar energy power generation is increased, and the power generation power of clean energy sources is improved.
2. The two energy sources are coupled through the waste heat boiler, the solar heat collection is utilized to replace the low-pressure evaporator of the waste heat boiler, and the operation is flexible and reliable.
3. The tail heater of the waste heat boiler is utilized to heat the solar heat collection and water supply, so that the exhaust gas temperature of the waste heat boiler is reduced, the heat exchange efficiency of the waste heat boiler is further improved, and the investment of a solar heat collection preheating zone is reduced.
Drawings
FIG. 1 is a schematic diagram of a solar-gas combined cycle power generation system of the present invention.
Reference numerals illustrate:
1. The device comprises a gas compressor, 2, a combustion chamber, 3, a gas turbine, 4, a gas turbine generator, 5, a high-pressure superheater, 6, a high-pressure evaporator, 7, a high-pressure economizer, 8, a high-pressure steam drum, 9, a low-pressure superheater, 10, a low-pressure evaporator, 11, a low-pressure economizer, 12, a low-pressure steam drum, 13, a high-pressure feed pump, 14, a tail heat exchanger, 15, a heat collection preheating zone, 16, a heat collection evaporation zone, 17, a steam-water separator, 18, a circulating pump, 19, a heat collection superheating zone, 20, a condenser, 21, a low-pressure steam header, 22, a turbine high-pressure cylinder, 23, a turbine low-pressure cylinder, 24, a turbine generator, 25 and a condensate pump.
Detailed Description
Embodiments of the present invention will be further described with reference to the accompanying drawings.
With reference to fig. 1, the invention aims to establish an energy utilization form of complementation of solar energy and gas-steam combined cycle, and aims to solve the problem of single energy utilization form, increase the complementation utilization of clean energy and improve the efficiency and continuity of system operation.
In order to achieve the above purpose, the solar energy-fuel gas combined cycle power generation system provided by the invention comprises a gas compressor 1, a combustion chamber 2, a gas turbine 3 and a gas generator set consisting of a gas turbine generator 4. The waste heat boiler consists of a high-pressure superheater 5, a high-pressure evaporator 6, a high-pressure economizer 7, a high-pressure steam drum 8, a high-pressure water supply pump 13, a low-pressure superheater 9, a low-pressure evaporator 10, a low-pressure economizer 11, a low-pressure steam drum 12 and a tail heat exchanger 14. The solar direct steam system consists of a heat collection preheating zone 15, a heat collection evaporation zone 16, a steam-water separator 17, a circulating pump 18 and a heat collection superheating zone 19. The equipment of the turbo generator set comprises a condenser 20, a low-pressure steam main pipe 21, a turbine high-pressure cylinder 22, a turbine low-pressure cylinder 23, a turbo generator 24 and a condensate pump 25.
The high-pressure superheated steam of the waste heat boiler is connected with the high-pressure cylinder of the steam turbine through a high-pressure steam pipeline, the low-pressure superheated steam of the waste heat boiler, the solar heat collection superheated steam and the high-pressure cylinder exhaust steam are connected with the low-pressure steam main pipe through a low-pressure steam pipeline, and the low-pressure steam main pipe enters the low-pressure cylinder of the steam turbine through a steam pipeline. And the high-pressure cylinder and the low-pressure cylinder of the steam turbine do work and then drive the steam turbine generator.
The exhaust temperature of the gas turbine is above 540 ℃, the temperature of the high-pressure superheated steam is 500 ℃, and the pressure is 5MPa. The temperature of the low-pressure superheated steam is 200 ℃, the pressure is 0.5MPa, and the outlet temperature of the tail heat exchanger is 80 ℃. The outlet pressure of the condensate pump is 1MPa, and the outlet pressure of the high-pressure water supply pump is 5.9MPa.
The use and the method of the system are further described below, namely, in rainy days or at night, the solar illumination intensity is insufficient, the heat collection temperature cannot meet the design requirement, and the solar heat collection field cannot be put into operation. At the moment, the unit is required to cut off the connection from the water supply to the tail heat exchanger and the solar heat collection superheating area to the low-pressure steam main pipe, and the gas-steam combined cycle unit continues to operate. When the unit is started. Firstly, starting a gas turbine, enabling smoke to enter a waste heat boiler, stabilizing the gas turbine at a low load, slowly heating up and boosting the waste heat boiler, increasing the load of the gas turbine after a certain pressure is reached, and slowly lifting parameters of the waste heat boiler to reach rated values. Secondly, in the temperature rising and pressure rising process of the waste heat boiler, high-pressure and low-pressure superheated steam is sent to the condenser through the bypass system, the bypass is slowly closed after the temperature and the pressure reach rated values, and main steam enters the steam turbine to do work. Finally, after all parameters reach rated working values, the gas turbine is loaded, and the load of the steam turbine is increased to rated values in a coordinated manner.
When the direct solar radiation intensity reaches the minimum value, condensation water is gradually started to a heat collection preheating zone of a solar energy field according to the radiation intensity, and the water supply flow of the heat collection field is adjusted according to the parameter change of heat collection superheated steam. The outlet of the low-pressure economizer of the waste heat boiler is slowly opened to the solar heat collection evaporation zone, and the flow quantity of the waste heat boiler is adjusted according to the outlet parameters of the heat collection evaporation zone.
The invention aims to provide a method, and specific unit start-stop and operation strategies, and related knowledge is known to a person skilled in the art.
The foregoing is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art, who is within the scope of the present invention, should be covered by the protection scope of the present invention by making equivalents and modifications to the technical solution and the inventive concept thereof.