中国电机工程学报Issue(5)：793-799,7.DOI:10.13334/j.0258-8013.pcsee.2014.05.012
CO2在立式螺旋管内流动沸腾换热的实验研究
Experimental Investigation on Flow Boiling Heat Transfer of CO2 in a Helically Coiled Tube
摘要
Abstract
Within the ranges of pressure from 5.6 to 7.0 MPa, mass flux from 54.0 to 400.0 kg/(m2⋅s) and heat flux from 1.4 to 48.0 kW/m2, an experimental investigation was conducted on flow boiling heat transfer of CO2 through a helically coiled tube. The test helically coiled tube has an inner diameter of 9.0 mm, a wall thickness of 1.5 mm and a coil diameter of 283.0 mm. The effects of heat flux, mass flux and operating pressure on heat transfer coefficient and inner wall temperature distribution were discussed. The experimental results show that the inner wall temperature distributions along the circumference were non-uniform. For the sing-phase liquid flow and the superheated vapor flow, the inner wall temperature was highest in the inside and lowest in the outside, attributing to the centrifugal force. But in the two-phase area, the highest inner wall temperature appears at the top, which is because that the vapor phase gathers at the top due to the buoyancy force, tending to dry out. The location where the lowest temperature happened is determined by the combined effects of buoyancy force and centrifugal force. The local average heat transfer coefficient increases with increasing heat flux and inlet pressure, but the increment of mass flux has no effect on the heat transfer, suggesting that the nucleate boiling is the dominant mechanism while the forced convection effect is weak. The intensity of nucleate boiling changes with increasing heat flux and the variation of heat transfer coefficient with vapor quality can be divided into three different zones, which is induced by the alternative of wall dry-out and rewetting. A new correlation of local average heat transfer coefficient has been proposed based on the 2 124 data points.关键词
流动沸腾/螺旋管/CO2/换热系数/参数影响Key words
flow boiling/helically coiled tube/carbon dioxide/heat transfer coefficient/parameters effect分类
能源科技引用本文复制引用
王淑香,张伟,徐进良,牛志愿..CO2在立式螺旋管内流动沸腾换热的实验研究[J].中国电机工程学报,2014,(5):793-799,7.基金项目
国家自然科学基金项目(51006035)；国家自然科学基金国际合作项目(51210011)；北京市自然科学基金项目(3132018)。National Natural Science Foundation of China (51006035) （51006035）
Project of International Cooperation and Exchanges NSFC (51210011) （51210011）
Beijing Natural Science Foundation (3132018) （3132018）
