槽式太阳能直接产生蒸汽系统(DSG)集热管传热特性研究

STUDY ON HEAT TRANSFER IN THE ABSORBER TUBE OF DIRECT SOLAR STEAM GENERATION

以DSG(direct steam generation)集热器的集热管为研究对象,利用数值模拟研究集热管内工质3种流态下周向温度分布及太阳辐射强度、工质流速、环境风速、环境温度、金属管材质等对金属管周向温度的影响。研究表明:集热金属管材质对周向温度分布影响较大,将铁材改为铜材时,过热蒸汽段最高温度从346.0℃降为338.0℃,最大温差从26℃降至约10℃;太阳辐射强度对壁面温度的影响较大,随着辐射强度的提高,壁温升高;工质流速对金属集热管壁面温度有一定的影响,当流速由0.8 kg/s提高至1.2 kg/s时,金属管周向最大温差由11℃下降至8℃,光斑处的最高壁温由321.5℃下降至318.7℃;环境风速和温度对周向温度分布的影响不大。

This paper uses numerical simulation to study the circumferential temperature distribution of working substance in collector tube under three flow patterns. It also studies the influences on the metal circumferential temperature by solar radiation intensity, working substance flow rate, environmental wind speed, environmental temperature and metal material. The research shows that：the metal material has much effect on the circumferential temperature distribution. If the material is switched from iron to copper, the maximum temperature under saturated steam will decrease from 346.0 ℃ to 338.0 ℃ while the maximum temperature difference will decrease from 26 ℃ to 10 ℃ ; When the radiation enhanced, the wall temperature increases respectively; the working substance flow rate also has some certain effect on the metal temperature. When the flow rate is increased from 0.8 kg/s to 1.2 kg/s, the metal maximum temperature difference will decrease from 11 ℃ to 8 ℃ while the light spot＇s maximum metal temperature will decrease from 321.5 ℃ to 318.7 ℃.