Study On The Numerical Simulation Of Rotor Cooling And Ventilation System In Air Cooling Turbo-Generator

Due to electrical losses and mechanical losses in the operation of the generator, heat is generated in different parts of a generator and if the heat can't be taken out, the rise of temperature may exceeds the allowed temperature of insulations and cause damage in different parts such as can damage or effect seriously the electrical insulation material. With the advance of the generator technology, the local distribution characteristics of the generator temperature with using many different methods, but the local characters can't give more supports the improvements on security and efficiency. Therefore, whether the global characteristics of the generator flow field and temperature field becomes important research on the rotor ventilation and cooling system of the turbo-generator.This article studied the rotor ventilation and cooling system of one air-cooled turbo-generator. According to its characters of ventilation, the whole physical model and numerical physical model of its fluid and components have been created. The results of its coupled fluid and temperature fields have been computed by the method of Conjugated Heat Transfer, including the mass flow, pressure, and velocity and temperature distributions of its fluid field, and the temperature distribution of its components. The elements which have influences on the distribution have been analyzed as well. The results of the research are that the designation of the rotor ventilation and cooling system can satisfy the demands because of the uniformities of the pressure distribution, the velocity distribution in conductors, temperature distributions in the fluid and its components and because there is no high temperature spots in the system, that the highest pressure of inlets of conductors in Rotor Body and End-winding are 33.45 KPa and 37.06 KPa respectively, and that the largest velocity of outlets is 216.91m/s, and that the slot L1 in the Rotor Body has the largest mass flow 0.112m3/s and the mass flow distribution depends on the number of conductor in slots and the area of the conductor cross section, and that the highest temperature in the components is 129.10? appearing in the middle of the conductors within the allowed temperature.In this paper with more actual conductor and End-winding structure, the non-accuracy of former methods has been avoid. And a better understanding of flow and heat transfer has been achieved for rotor cooling and ventilation system. With the results analysis, useful suggestions has been presented which can be the key points to inspection, operation and optimization of same type.