The vacuum of condenser has an important influence about economy and security of steam turbine,and it was affected by many factors which had biggish couple,so it is difficult to confirm the norm vacuum of condenser.

A soft sensing model for norm vacuum of condensor based on data fusion is proposed due to the enhancement of the accuracy and reliability.

Aiming at the fact that the vacuum value of 4# steam turbine is slightly higher,and based on full examination and analysis,the solutions to decreasing the vacuum value of steam turbine are carried out.

Form the point view of condenser and cooling tower, this paper discusses the calculational methods of condenser back pressure target value as an example of closed circulating water system.