Exergy Analysis Of Thermal Systerm For PWR Nuclear Power Plant

By2015,there will be40sets of nuclear power units put into commercial operation in China.The installed capacity of nuclear power units will reach4000kilo-watts.The proportion of the installed capacity of nuclear power units is larger and larger in our country’s electric power industry. What have got more and more the attention of the people is the theoretical research on energy conservation of nuclear power units.Utilizability method what based on the second law of thermodynamics can reveal the real reason of the energy loss of nuclear power units during the operation,so we will apply utilizability method to the economic analysis of PWR reactor nuclear power units.Firstly,according to the characteristics of thermal system of PWR nuclear power plant. the thermal system is divided into six control body.that reactor,steam generato-r,heat recovery system and reheat system,turbine,separator and condenser.According to the distribution of exergy,the exergy balance equations of each control body are listed.Secondly,it is based on the water-steam distribution matrix equation and exergy loss distribution matrix equation of reheat system and heat recovery system,according to perturbation theory and differential theory,the influence of exergy economic indicators to extraction steam pressure loss,terminal temperature difference and heat loss is deduced.Measures of improving the efficiency of the PWR nuclear power unit is given.We get the following conclusions by calculating.The equipment what have the largest exergy loss is reactor during the operation.The reason is the irreversible loss of the two processes of nuclear energy is converted to heat energy and the high grade thermal energy is converted to low grade thermal energy.In addition,what have more influence on economy of unit is terminal temperature difference of No.4,extraction steam pressure loss of No.1and heat loss of No.7,so we should reduce the terminal temperature difference of No.4, the extraction steam pressure loss of No.1and heat loss of No.7.