Rapid hot air cooling after the shutdown of steam turbine is widely used scheme in practice. In this paper,on the basis of the variable temperature and flow devices (double-variable),a new method is designed to produce such rapid hot air cooling steam turbines. Taking 300 MW steam turbine for example,this paper utilizes Ansys software to compute the flow of variable air and the temperature fields of cylinders according to rapid hot air cooling,traditional hot air cooling and the natural cooling method respectively. The result shows that it enlarges the flow and decreases the cooling time,while the temperature gap is increased between the upper and lower cylinders as well as the inner and outer ones. Compared with traditional methods,this new one has certain advantages like its high cooling speed,uniform temperature field,and lower temperature gap both in the inner/outer cylinders and in that of its axial direction.
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