An increasing number of coal and oil fired boilers are employed in covering the week day load and are shut down at weekends. Therefore the ability for heat recovery from starting vessel will directly affect the economy of the operation in a once through boiler unit. This paper describes an attempt to calculate the amount of heat recovery in a once through boiler system during its start up. A mathematical model has been firstly developed and an experimental study is carried out to check the model. The 300?MW... An increasing number of coal and oil fired boilers are employed in covering the week day load and are shut down at weekends. Therefore the ability for heat recovery from starting vessel will directly affect the economy of the operation in a once through boiler unit. This paper describes an attempt to calculate the amount of heat recovery in a once through boiler system during its start up. A mathematical model has been firstly developed and an experimental study is carried out to check the model. The 300?MW and 600?MW once through boiler system are taken as the examples. The pressure rise rate, pressure rise curve and recoverable heat analysis which are significant to improve the operation reliability and economy for the domestic made deaerator tanks have been given out. Both theoretical analysis and experimental studies show that the capacity for heat recovery in the deaerator tank largely depends on the working pressure of the deaerator tank and the starting vessel. The volume of the deaerator tank, especially the volume of water has a large effect on the heat recovery capacity. These analysis results can be applied to the design and operation control of the deaerator tanks. |