Ruan Lin

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.

Research on loop resistance in self-circulation evaporative cooling system of stator collector ring of hydro-generator

Self-circulation evaporative cooling system of stator collector ring of hydro-generator is a new cooling system, with advantage of high-security, energy-saving and high efficiency. In this paper, the loop resistance in single stator collector of hydro-generator was analyzed deeply and detailedly, by experiment and simulation. The simulation method of system resistance was introduced. The comparing results between experimental data and simulation results show that the prediction precision of pressure distribution of coolant in system is satisfying and the simulation method is reliable and can be utilized in application engineering field.

Heat transfer characteristics of spray evaporative cooling system for large electrical machines

In 2010, the spray evaporative cooling technology was applied successfully to large electrical machines by IEECAS. But the heat transfer mechanism of two-phase spray cooling has not been studied in detail. Based on the engineering application, in this paper, the heat transfer characteristics of the spray evaporative cooling system will be discussed. The conclusion will provide reference for the design of spray cooling system in large electrical machines.

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.

The effect of spray parameter on heat dissipation in spray evaporatvie cooling high power density motors

With the increase of the electrical machines capacity and voltage level, the main insulation of the stator coil becomes thicker. Heat dissipation and voltage endurance becomes a contradiction. The traditional cooling, such as air-cooling and water-cooling, will not well meet design needs. New cooling methods with both advantages of good cooling effect and good insulation are in keen demand in industry. The spray evaporative cooling system should have the advantage of higher heat transfer efficiency, less power consumption and decreasing motors weight. The paper aims to study how key spray parameters affect the heat transfer in the large electrical machines. The experimental result is the key reference for the motor cooling system optimization design.

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.

The experimental studies on spray parameters in spray evaporatvie cooling motors

Spray cooling is a new type of high heat flux heat transfer cooling technology. In the process, cooling medium is dispersed certain microscale droplets through the nozzles and injected to the stator core and winding. The spray characteristics will affect directly the heat transfer coefficient. So in the paper a test rig using a nozzle was constructed to explore the atomization characteristics of spray. Spray parameters (including droplet diameter and particle velocity) were captured by using a phase Doppler Particle analyzer. The basic principle and the measure test of PDPA are also described. The experimental result is the key reference for the motor evaporative cooling system design.

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.

Instability analysis of forced circulation evaporative cooling ECRIS solenoids

This paper introduces a forced circulation evaporative cooling ECR ion source solenoids, through experimental research and theoretical analysis, we proved that there exists instability characteristic and this instability cannot be avoided for such a high power density application. Furthermore, we put forward an alternative cooling structure, immersion natural circulation cooling system, which performance is much better than previous water cooling ECRIS.