Thermal Economics Analysis On The System Of The Thermal Power Plant Combined With Nuclear Power Plant

The combined power plant,based on the efficient coal-fired power plant and aided with other clean energy,effectively reduce the consumption of fossil energy which release the pollution when in combustion.The combined power plant can also promote the development of clean energy power,and through the complementary advantages and disadvantages between different energy sources is the main trend of power plant development.This paper puts forward the Thermal power plant combined with Nuclear power plant,Coal-fired power plant is more efficient and economy,while Nuclear power plant is more friendly-environment.The combined system can integrate the characteristic of the two energy sources,the two kinds power plant can learn from each other and develop together.The main differences between Thermal power plant and Nuclear power plant are their fuel and steam parameters,which make the two plant have the potential for further optimize.The basic principle of the combined system is Nuclear for the low temperature working fluid and the coal for the high temperature,through the cascade unitization of energy,improve the power efficiency.According to different working parameters and equipment,four kinds scheme of Thermal power combined with Nuclear are proposed: series connection scheme;parallel I with boiler and regenerator;parallel II with boiler and regenerator and direct heating scheme.For the target of energy-saving and emission-reduction,two kings index are presented: nuclear proportion and power efficiency.The results show that the efficiency of series connection scheme is highest,however the proportion is too low,less than 15%.The direct heating scheme can reaches the extreme value of proportion and its power efficiency is the second highest.To sum up,the direct heating scheme is the best one in the four schemes.In this paper,the exergy analysis is used for the study of direct heating scheme of thermal and nuclear combined power plant.The study is for the energy consumption of each equipment and process.Compared with the nuclear power plant,the exergy loss distribution is similar: the steam generator an d boiler have the largest loss,followed by turbines.The exergy efficiency of boiler and turbine in combined power plant is higher than nuclear power plant,which is the main reason for high efficiency of the combined power system.After exergy optimization,the efficiency of combined system can reach 40.63%,which is nearly 5 points higher than nuclear power plant.In this paper,the structural theory thermoeconomics analysis,which can use the exergy cost theory to present the fuel consumption of each equipment,is utilization for the study of the optimized system by exergy analysis,the result showed that the economics of fuel.And the analysis of economics of equipment of the combined system can also prove the economics of combined system is h igher than a thermal and a nuclear power plant.The above analysis fully demonstrates the feasibility of the Thermal power plant combined with Nuclear power plant.