The papcr briefed the problems found in the operation after the mechanical draft cooling system was installed,including:loosening of belt,output decreased in the rainy days,uprating of system, accumulation of impurities,too high return water pressure,use of industrial water ere.

The product properties such as tensile strength and electric conductivity effected by cooling strength and deformation were studied.

Compounds in 7A52 alloy may not influence the processing property of product by means of three process parameters,such as,controlling the main element Mn in 7A52 alloy,and by aid of special moulding system and reasonably controlling cooling strength.

Because taking some measures,such as selecting hot air valve with reasonable structure,improving cooling system of hot air valve and increasing cooling strength of hot air valve,etc,the service life of hot air valve is increased greatly in the practical process of vapourizing cooling of hot air valve in NO.

After transformation, the circulating water of 2# 750m3 BF is increased to 1230 m3/h, the head of circulating pump is increased to 60m, and the intensity of cooling is improved, the life of cooling stave is extended to 2 years, the system's operating security is improved, and the annual benefit of power economy is 0.

Operation and analysis of turbine forced cooling for 300 MW units in Mawan Power Station;

Effect of forced cooling on life loss of HP rotors of 200 MW steam turbines;

Operation analysis of turbine forced cooling for 700 MW units in Zhuhai Power Station;