基于相变储热的太阳能多模式采暖系统及应用

Solar multi-mode heating system based on latent heat thermal energy storage and its application

为克服太阳能间断性和不稳定性的缺点进而实现太阳能集热与采暖的能量供需调节和全天候连续供热,提出了基于相变储热的太阳能多模式采暖方法(太阳能集热直接采暖、太阳能集热采暖+相变储热、太阳能相变储热采暖),并在西藏林芝市某建筑搭建了太阳能与相变储热相结合的采暖系统,该系统可根据太阳能集热温度和外界供热需求实现太阳能多模式采暖的自动控制和自动运行。实验研究表明:在西藏地区采用真空管太阳能集热器可以和中低温相变储热器很好地结合,白天储热器在储热过程中平均储热功率为10.63 kW,储热量达到92.67 kW·h,相变平台明显;晚上储热器在放热过程中供热量达85.23 kW·h,放热功率和放热温度平稳,储放热效率达92%,其储热密度是传统水箱的3.6倍,可连续供热时间长达10 h,从而实现了基于相变储热的太阳能全天候连续供热,相关研究结果对我国西藏地区实施太阳能采暖具有一定的指导作用。

To overcome the discontinuity and instability of solar energy and achieve energy supply and demand regulation and all-weather continuous heating supply of a solar heating system, a solar multi-mode heating method based on latent heat thermal energy storage is proposed. A solar heating system combining integrating vacuum-tube collectors with a latent heat thermal energy storage device is established in a building in Linzhi city, Tibet. The system can perform automatic control and operation of solar multi-mode heating according to the operating condition of solar collectors and external heating demand. Experimental studies show that the vacuum-tube solar collectors can work collaboratively with the latent heat thermal energy storage device. During the daytime, the latent heat thermal energy storage device performs a heat storage with an average charging power of 10.63 kW and a storage capacity of 92.67 kW·h, and the temperature platform of phase change can be apparently observed. At night, the thermal energy storage device can provide a 10-hour continuous discharging process with a total heat output of 85.23 kW·h at a stable discharging power and temperature. The charging-discharging efficiency of the storage device is 92%, and its heat storage density can reach 3.6 times that of a traditional hot-water storage tank. The results indicate that the solar heating system can achieve all-weather continuous heating supply. The present study can provide guidelines for implementation of solar heating in Tibet.