太阳能—低温热管地板辐射供热系统实验研究

EXPERIMENTAL INVESTIGATION ON THE PERFORMANCE OF SOLAR-THERMOSYPHON EMBEDDED RADIANT FLOOR HEATING SYSTEM

为将低品位太阳能直接应用于建筑供暖,对一种太阳能—低温热管地板辐射供暖系统进行了实验研究。在天津地区冬季条件下、供水温度为35～45℃时,针对非节能建筑的房间负荷(30～60 W/m^2)进行了该系统各部件和系统整体性能的实验。实验结果表明:供水温度35～45℃即可满足采暖要求;太阳能保证率受供水温度影响显著,供水温度升高10℃,太阳能瞬时保证率减小5%;晴朗白天,室外平均温度-0.72℃,平均太阳辐照度425.1 W/ m^2,太阳能瞬时保证率近似为1;阴天室外平均温度-1.55℃,平均太阳辐照度220.5 W/m^2,太阳能瞬时保证率随供水温度和负荷的变化而变化,范围是0.52～0.96。实验证实:该系统能提高太阳能热利用的经济性,热管地板传热性能优于塑料埋管地板,供水温度可以比常规塑料埋管地板的要求降低约5℃。

To apply low-grade solar energy to building heating system, a new solar-thermosyphon embedded radiant floor heating system （STERFHS） was studied. Experimental research of the influence of meteorology, supplied water temperature （35 - 45℃ ）and room heating load （30 - 60 W/m^2 ） on the performance of STERFHS in Tianjin, China was done. Experiment results indicate that supplied water temperature between 35 - 45 ℃ can meet the heating demand and has a notable effect on the solar fraction. The solar fraction can be reduced by 5 % when the supplied water temperature is increased by 10℃. The solar fraction approximated to 1 in sunny day with the average outdoor temperature of - 0.72℃ and the average solar radiation of 425.1 W/m^2, while the solar fraction varied between 0.52 - 0.96 with supply water temperature and heating load in cloudy day when average outdoor air temperature was - 1.55℃ and average solar radiation was 220.5 W/m^2. The experiment results also show that STERFHS could improve the economy of solar heating system and have much better heat transfer performance than the common plastic embedded radiant floor. The temperature demanded by STERFHS can be reduced by 5 ℃ compared with the plastic embedded radiant floor.