For the spray system

there is few engineering applications and the experience of system design and operation is insufficient. To solve these problems and promote the application of this technology

the design features

advantages and application of the spray system in separated system of low pressure economizer and air heater were introduced. In the separated system of low pressure economizer and air heater system

there are two ways to return the condensed water cooled by the air heater

which improves the reliability and stability of the system. A part of the condensed water cooled by the air heater is sprayed into the turbine exhaust pipe through the spray system

which can cool part of the steam in the cooling tower

reduce the back pressure

save the coal consumption

reduce the steam extracted from No.7 low pressure heater

and increase the energy-saving benefits. Taking a 600 MW air cooling unit as the example

economic analysis for the separated system under different conditions were carried out. The results show that

the energy conservation potential of the spray system increases at first and then decreases with the increasing ambient temperature at the same load. Moreover

the energy conservation potential increases with the decrease of the water temperature at the air heater outlet. It suggests that the spray system should be put into operation when the difference between the water temperature at the air heater outlet and the saturation temperature of the steam in the cooling tower exceeds 5 ℃. In the actual project

the annual average energy conservation potential of the spray system is 0.141 g/(kW·h) and the static payback period is 4.41 years.