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以太阳能与燃料电池耦合系统为应用背景,对不同管长和管径、不同吸收率和发射率和有/无内置导流板3种不同情况下的太阳能集热器进行试验研究.建立太阳能集热器自然对流和强迫对流数值计算模型,并应用场协同和火积理论分析模拟计算数据.自然对流研究表明,随着真空管长度的增加,水箱温度逐渐升高,但集热效率逐渐下降;当吸收率在0.95~1.0范围内升高,发射率在0.16~0.06范围内降低时,集热效率逐渐上升;全玻璃真空管加装导流板后,由于真空管中混流消失和真空管底部强化传热作用而提高了太阳能集热器的热效率.强迫对流研究表明,横双排太阳能集热器的雷诺数、努赛尔数和火积增量均高于竖直单排太阳能集热器;横双排太阳能集热器的火积耗散低于竖直单排太阳能集热器.研究结果表明,在中低温太阳能耦合燃料电池集热场,自然对流宜采用内置导流板太阳能集热器,强迫对流宜采用横双排太阳能集热器.
Taking solar energy and fuel cell coupling system as the application background, the solar collector with different tube length and diameter, different absorptivity and emissivity and with / without built-in deflector was tested and studied.Construction of solar energy set The natural convection and forced convection numerical models were used to analyze the simulation data with field synergy and fire product theory.The results of natural convection show that with the increase of vacuum tube length, the temperature of the water tank gradually increases but the efficiency of heat collection decreases gradually. The rate of heat collection increased gradually when the rate was in the range of 0.95 ~ 1.0 and the emissivity decreased in the range of 0.16 ~ 0.06. After the all-glass vacuum tube was installed with the deflector, the disappearance of the mixed flow in the vacuum tube and the enhanced heat transfer at the bottom of the vacuum tube The research on forced convection shows that the Reynolds number, Nusselt number and fire accumulation increment of horizontal double-row solar collectors are both higher than those of vertical single-row solar collectors. Horizontal double-row solar collectors The heat products’ dissipation is lower than that of vertical single-row solar collectors.The results show that the natural convection should be built-in baffle too Yang collector, forced convection should be horizontal double row solar collectors.