Research on gas-liquid-solid insulation system in stator slot
In evaporative cooling turbogenerator, all structures are immersing in evaporative cooling medium. Evaporative cooling turbogenerator which is transformed from inner water-cooling turbogenerator has been developed successfully. However, it has not taken full advantage of evaporative cooling medium's superiority in insulation. Besides, the amount of cooling medium is relatively large. This paper redesigns and analyzes gas-liquid-solid insulation system in stator slot from the perspective of the evaporative cooling technology. Furthermore, this paper provides the most appropriate materials and optimum thickness for solid insulation layer and fixed insulation layer in new insulation system. At last, this paper discusses wrapping width and interval of fixed insulation layer by three-dimensional model of new-designed insulation system.
Characteristics of the evaporative cooling technology for the large turbine generator and its analysis
The cooling technology is one of the key technologies for developing large capacity turbine generator. A 300MW turbo-generator with evaporative cooling technology was designed, manufactered and tested. In this paper we provide the design features, tested results and the advantages of applying the evaporative cooling technology for the large capacity turbo-inegenerator.
PRESSURE DROP FOR OIL-GAS TWO-PHASE FLOW THROUGH STRAIGHT HORIZONTAL PIPE
An experimental investigation on oil air two phase flow through a straight horizontal plexiglass pipe within 40 mm inner diameter was conducted.The superficial velocity ranges of oil and air were 0 05—0 612 m·s -1 and 0 024—50 64 m·s -1 , respectively.The ambient temperature was maintained throughout the experiments.The frictional pressure drop multiplier of two phase flow was expressed using the Lockhart Martinelli parameter correlation in accordance with typical flow pattern, but the modification factor C in the correlations was defined afresh according to flow conditions.New predict correlations for pressure gradient in accordance with typical flow patterns were proposed and the mechanisms of pressure drop production were analyzed for each flow pattern.The proposed models gave good agreement with the experimental data.