新型太阳能温差发电集热体的传热特性

Heat transfer characteristics of novel heat collector on solar-thermoelectric power generation

面向中低温区太阳能集热技术的供能配置需求,提出兼具聚光和蓄热2项功能的新型集热体结构.以杭州地区为例,针对集热体表面阵列排布的点热源群采用Fluent软件建立三维流-固耦合传热模型,并在稳态工况下讨论分析集热体蓄热特性的关键参数及其作用规律.仿真优化结果表明：当太阳辐射强度达到800~1 000 W/m2,且集热体中蓄热模块的铜盘管管径为5mm、管内导热油流速为0.2m/s时,即使在半导体温差发电堆的冷源侧仅采用常规强迫对流风冷散热,该集热体也能为半导体温差发电系统的热源与冷源之间持续提供80~104℃的理想工作温差,对应的电功率输出为3.8~5 W,发电效率为4.8%~5.3%.

A novel heat collector fixed in solar-thermoelectric power generation unit was proposed with the functions of tracking the sunlight and accumulating heat, for the demand of solar energy collection technol- ogy in medium - low temperature zone. Based on a specific project in summer of Hangzhou, a three-dimen- sional fluid-solid coupling heat transfer model of the array of point heat sources on the heat collector was established by Fluent software. The further investigation on the interaction characteristics of the key pa- rameters to the heat storage capacity in the steady-state operating condition was conducted. Results indi- cate that if the solar radiation intensity stays between 800 and 1 000 W/m^2 , coupled with the copper coil diameter of 5mm and the heat conduction oil flow rate of 0.2m/s, the temperature difference between the heat source side and cold source side can maintain at an optimum temperature range of 80~104 ℃ for pow- er generation even with a conventional forced convection air-cooling heat dicepation at cold side. The sup- ply power output was 3.8~5 W and the power generation efficiency of 4.8~5.3%.