| The continuous cleaning of energy structure is the trend of the times.Solar thermal power generation has developed rapidly in recent years.Combining solar power and coal-fired power generation can not only increase the share of renewable energy,but also reduce pollutant emissions and fuel consumption.Based on the current research and application status of solar energy assisted coal-fired power generation technology,this paper has deeply learned about the technical level and conditions in related fields,and has synthetically analyzed the characteristics,laws and deficiencies of some integrated solutions.Following the principle of energy matching,two types tower solar assisted coal-fired power plant is proposed in this paper,and the tower solar energy belongs to high temperature solar thermal utilization technology.Reference to a 600 MW subcritical coal-fired units,tower solar energy is used to heat part of the boiler superheated steam to replace part of the coal-fired heat.The steady-state thermal performance of the tower solar assisted 600 MW coal-fired power station is simulated by using the simulation software EBSILON Professional.With the increase of extraction ratio,the changes of operating parameters,performance indicators and economy of the coal-fired units is analyzed.The simulation calculation result shows that the extraction of steam to the tower solar system will lead to the decrease of exhaust gas temperature,the increase of thermal efficiency and the decrease of exergy efficiency.The overall economy of the complementary integrated system is improved,and the coal consumption in the first scenario is about 4.062 g/kW·h at a steam extraction ratio of 10%.Through the calculation and analysis,the operating mode of boiler extraction which is heated by the solar tower system and directly sent back to the power station boiler is more economical and safety.The dynamic response of the complementary unit after extraction is sent to the solar tower system is obtained by using the transient simulation software TRNSYS.The simulation result shows that the days when the DNI value fluctuates can cause the temperature of the superheated steam and reheated steam to fluctuate greatly,which will seriously affect the safe operation of the unit.The integrated mode of the extraction is sent back to the coal-fired boilers has a much smaller impact on the operating parameters of the coal-fired boiler than the integrated mode of the extraction is not sent back.Therefore,in the two adopted types of solar tower assisted coal-fired units,the integrated mode of the extraction is directly sent back to the boiler is better than the mode of the extraction is sent to the condenser after energy working,which has less influence on coal-fired boiler and higher thermal economy. |
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