MICROSTRUCTURE ENHANCED HEAT EXCHANGER FOR PRESSURIZED WATER REACTOR
The goal of this research is to enhance the heat exchanger efficiency of pressurized water reactor (PWR) by using LIGA or LIGA-like technique made microstructures. The heat transfer inside the boiler is a complex combination of different physical phenomena, which, besides the traditional convection,conduction, and radiation, includes liquid to vapor phase change,vapor nucleation and evolution, surface tension between the liquid and heating element, and so on. This paper presents the updated total heat transfer enhancement results of the boiling process by adding microstructures on the surface of the heating elements. Different types of microstructure configurations were tested. The power input, temperature of the heating element, and boiling phenomena were recorded. The behavior of increase in power versus rise in temperature of testing coupon is used to evaluate the heat transfer efficiency of the heating element. The steam generating efficiency at fixed input power and fixed temperature have been used to assess the performance of heating elements with different microstructure configurations.The preliminary results show that by simply adding microsized poles on the surface of the heating element, the power input can be increased almost 100％ higher than that without poles on the surface at 360oC. The current results suggest that the main factors leading to the enhanced boiling process are the surface morphology and configuration of the microstructures. These provide enhanced vapor nucleation sites at heating surface, which result in a better vapor evolution processes, and yield a low superheat temperature. It ultimately results in a higher boiling heat transfer efficiency.
Kun Lian Min Zhang Guoqiang Li Su-Seng Pang Zhong-Geng Ling Chang-Geng Liu Samuel Ibekwe
Louisiana State University, Center for Advanced Microstructures and Devices, Jefferson Hwy. Baton Ro Louisiana State University,Mechanical Engineering Department, Baton Rouge,Louisiana 70806, USA Southern University,Mechanical Engineering Department, Baton Rouge,Louisiana 70806, USA
国际会议
海南三亚
英文
2007-01-10（万方平台首次上网日期，不代表论文的发表时间）