The performance of cold end system for thermal power unit directly affects the thermal economic efficiency and safety of the whole unit.Directing against the cold end system of unit no.4 in Shajiao A Power Plant

the optimal operation mode of circulating water pumps under different loads and different temperature of circulating water has been studied and obtained.Through caculation under variation of operating conditions

the terminal temperature difference of condenser

the temperature rise of circulating water

and standard value of exhausted steam temperature under different operating conditions of unit have found.The economic efficiency diagnosis at cold end system of said unit shows that the terminal temperature difference of condenser for this unit in winter and spring season was somewhat higher

this is due to steam condensation in pipeline connecting to the vacuum pump

there fore

the monitoring should be strengthened

and the condensate thereof has to be timely discharged

so as to enhance th economic efficiency in operation of unit.