The Study And Numerical Calculation On The Evaporative Cooling Of Hydro-Generator

Evaporative cooling has been regarded as a new cooling technology on hydro-generator, and it not only could increase the ratio of material utilization and reduce the difficulties of making large-scale hydro-generators, the running difference in temperature, the stress of the generator's stator and the possibilities of the incidental occurrences, but also has better performance than internal water cooling.The temperature field's calculation on the hydro-generators stator was one of the main in design, which was related to the life of generator and the reliability of operation. The accurate calculation is very important. With the development of computer technology and numerical method, the domestic and oversea researchers have acquired a lot of practical findings in recent years.In this paper, a study on two-phase flow and heat exchange inside pipe was made in theory, and the source program used in calculation of temperature distribution of coolant and wall along hollow wire was modified. The theoretical calculation has a good agreement with the test result in a 400MW hydro-generator. Many factors that effect coolant flow and heat exchange was analyzed. Based on the wall temperature of hollow wire, the further calculation program has been given. It account for the complexity of the stator's structure and can be used in the calculation of the temperature distributions in arbitrary cross section of windings.