Gu Guobiao

Research of the Temperature Distribution of the Hollow Conductor in the Evaporative Cooling Hydro-Generators

This article aims to present an effective calculating method for computing the temperature distribution along the length of hollow conductors in the stator bars of evaporative cooling hydro-generators. A kind of partition of flow patterns was adopted and the corresponding convective heat exchange coefficients were calculated according to the different flow patterns. Comparative results show that the calculating temperature distribution is in accord with the experimental measurement to about 10% relative error. On the whole, this calculating model is reliable and can be used in the applied engineering field.

Temperature characteristics in the stator model of a permanent magnet motor by water-cooling and evaporative cooling

An experimental model, which is realized by combining technologies of the water-cooling and the evaporative cooling, is presented. The principle of the evaporative cooling technology is described thoroughly. The comparison of the cooling effects by two cooling techniques has been done. A PM motor adopting the evaporative cooling technology for underwater apparatus is introduced also.

The analysis and simulation experiment of stator cooling for large evaporative cooling turbo generator

when we design immersing evaporative cooling turbo generator, How to control the temperature rise of stator bars in an appropriate situation is one of the most important parts in the unit designing. In this paper, the heat flowing paths of stator components are analyzed in the immerging stator structure. Based on the heat transfer theories, Numerical simulation model is built for the stator temperature distribution. The FEA (Finite Element Analysis) is used to the simulation analysis, and get the temperature rises of parts and the heat fluxes of heat flowing paths. To verify the analysis and calculation results, we built the experiment model of stator. Compare the calculation results with experiment results, and we get many valuable analytical methods and designing criterions for evaporative cooling turbo generator.

The design of the condenser in the evaporative cooling hydro generators

The condenser is the key component in the evaporative cooling hydro generator. The design of the condenser will directly affect the performance of the whole evaporative cooling system as well as the temperature distribution of the stator bar. So, this paper introduced the method of the arrangement of condensers and the design of the capacity of each single condenser. Especially, under unsymmetrical operating state of the condenser, the influence of which on the cooling effect was analyzed. This will provide the reference for the design of the condenser.

Research on the two phase flow of evaporative cooling system in higher power density ECRIS magnet

The Power density of ECRIS magnet coil is larger than 3000kW/m3, and evaporative cooling technology is an ideal method to achieve the cooling requirement. The two phase flow of evaporative cooling system affects the cooling efficiency of coil. This paper introduces the self-driven evaporative cooling system of magnet, and analyses the pie structure of magnet coil and two phase flow channel in the coils. To coordinate contradiction between structural strength of coils and flow resistance, the CFD model of flow channel is built and the computational model of two phase flow is used to simulate the fluid field. The experiment model of coils is built to verify the calculation. The comparisons between simulation and experiment results show that the simulation method can satisfied the application of project.

Study on overload performance enhancement of motor based on heat storage of phase change paraffin

Overload performance of permanent magnet motor is very important for some special occasions, which has been generally limited by temperature rise of stator. This paper introduces a new method based on heat storage of phase change paraffin to enhance the overload performance of motor. The heat variation of motor was analyzed under overload process, and the key affecting factors were given to control the temperature rise. According to the structure of permanent magnet motor, this paper analyzed the influence of cooling structure for phase change paraffin and given three cooler designs (pure paraffin, aluminum plate-fin and heat pipe cooler). The experiment models of cooler designs were built to verify the analysis.

The evaluation of the design and operation of the 400MW evaporative cooling hydrogenerator in LiJiaXia hydropower station

The 400MW evaporative cooling hydrogenerator in Lijiaxia hydropower station has been serving for more than 15 years. This paper gives a comprehensive evaluation of this unit from cooling mode selection, electrical magnetic scheme design, operating practice and temperature distribution. The application of the evaporative cooling technology to 400MW-grade hydrogenerator shows great advantages comparing with the same capacity air cooling units, which demonstrates the correct of design and the stability and safety of long-term operation.

Studies on the structure of radial ventilation channel to improve the cooling capacity of large turbo generator stator

Radial ventilation channel is a key component of large turbo generator stator, which affects the cooling of stator core and bars. The design of radial ventilation channel need simultaneously consider the flow resistance and cooling capacity. In this paper, the width of radial ventilation channel, the structure and material of support parts will be discussed to improve the cooling capacity of large air-cooled turbo generator stator. The theories of Computational Fluid Dynamics (CFD) and heat transfer are used to calculate the flowing field and temperature field, and the simulation results will be compared with experimental data of a 150MW air-cooled turbo generator.

Thermal analysis and optimization of the stator structure of a submerged cryogenic induction motor

The submerged cryogenic induction (SCI) motor is a key component of a submerged liquefied natural gas (SLNG) pump. In this paper, A lumped-parameter-based thermal analysis applicable to the stator of a 15 kW SCI motor for the SLNG pump is presented. The corresponding stator winding losses is calculated based on the thermal analysis result. In order to reduce the stator winding losses, the stator structure of the 15 kW SCI motor is optimized to improve the heat dissipation of the stator windings.

Improvement of inner evaporative cooling experiment model for large turbo generator stator bars

Inner evaporative cooling way of stator bars is generally affected by circulating system and coolant. In this paper, we focus those factors to improve the capability of cooling system. Based on the flowing resistance distribution of system, the structure of components is redesigned to improve the stability and reliability of circulating flow. In the same time, different kinds of coolant are used into the inner evaporative cooling experiment model. The experiment results show that boiling point and viscosity of coolant are the main factors of improvement. The cooling efficiency of hollow strands is improved by new experiment model and coolant, and the structure of improved model and coolant ZF-2 can perfectly satisfy the cooling requirement of 300MW turbo generator.