Thermoelectric devices are one of the technologies used either to generate electricity by applying a temperature difference using thermal energy or as a heating/cooling system by applying an electrical voltage.The num...Thermoelectric devices are one of the technologies used either to generate electricity by applying a temperature difference using thermal energy or as a heating/cooling system by applying an electrical voltage.The number of materials required to produce a product is an important factor in determining its price.Production costs associated with these materials,as well as their availability and quality,play a crucial role in price determination by manufacturers.In this context,a method that employs a uniform volume distribution was implemented.This approach enabled the analysis to focus on other variables,thereby promoting a more precise and relevant evaluation of overall performance.Based on the finite element method,this study investigated the influence of geometric shape,including Rect-leg,Y-leg,Pin-leg and X-leg designs,on the performance of solar thermoelectric generators and thermoelectric coolers.The study was conducted considering the same hot alumina junction surface that receives solar radiation;however,the ef-fective surface,which corresponded to the heat flow area and had a similar area near the exposed surface,varied depending on the chosen leg geometry,thus impacting the heat flux due to the variation in thermal resistance.In the case of a solar thermoelectric generator,the Rect-leg model,having the same effective surface area,presented the lowest heat loss value resulting from convection and radiation in the heat spreader and the hot alumina plate.Under the same conditions,the Y-leg showed the highest value.The Rect-leg design generated,by using thermal and optical concentration,the highest output power of 0.028 and 0.054 W,and efficiency of 3.47%and 4.7%,respectively,whereas the Y-leg generated lower values of 0.006523 and 0.018744 W for power,and 2.83%and 2.71%for efficiency,respectively.In the case of the thermoelectric coolers,the Y-leg generated the highest temperature difference between the hot and cold sides of 67.28 K at an electric current value of 1.8 A,whereas the Rect-leg,Pin-leg and X-leg generated~66.25,~67.02 and~67.19 K at 6.1,2.7 and 2.6 A.展开更多
文摘报道了一种实现高能量输出的激光二极管(LD)泵浦无水冷全固态Nd∶YAG双程放大器结构。整个放大系统采用了泵浦与晶体棒集成的模块以及半导体制冷器(TEC),从而实现了激光系统的小型化。总腔长为730 mm。在10 Hz重复频率下,主振荡器得到了最大脉冲能量为350 m J的激光输出。脉宽为9.7 ns,光束质量M^2在两个方向分别为7.7和12.3。并进行了双程放大的研究,双程放大后得到了740 m J、10 ns的激光输出。
文摘【目的】为了解决从空气中取水的高能耗和低效率问题,设计了一种利用热电制冷器(thermoelectric cooler,TEC)进行空气制水的装置。【方法】首先结合空气冷凝制水原理,利用TEC将散热翅片表面温度降低至露点温度以下;然后使装置与空气进行热量交换,从而实现空气中水蒸气的冷凝;最后考察了在不同输入电压和散热翅片面积下TEC的热力学参数对系统的能效比(coefficient of performance,COP)及比能耗的影响。【结果】当输入电压为4 V、热端循环冷却水流速为0.3 L/min、散热翅片面积为20320 mm 2时,空气制水器比能耗最低,为2135.27 kW·h/m 3,系统的最佳COP为2.7。相对于现有研究,本试验通过对空气制水装置输入电压和散热翅片面积等参数的优化,将从空气中制水的能耗有效降低了13.8%。【结论】本研究结果为降低空气制水过程中的高能耗和提高空气制水过程中的系统效率提供了一定的技术支持。
文摘Thermoelectric devices are one of the technologies used either to generate electricity by applying a temperature difference using thermal energy or as a heating/cooling system by applying an electrical voltage.The number of materials required to produce a product is an important factor in determining its price.Production costs associated with these materials,as well as their availability and quality,play a crucial role in price determination by manufacturers.In this context,a method that employs a uniform volume distribution was implemented.This approach enabled the analysis to focus on other variables,thereby promoting a more precise and relevant evaluation of overall performance.Based on the finite element method,this study investigated the influence of geometric shape,including Rect-leg,Y-leg,Pin-leg and X-leg designs,on the performance of solar thermoelectric generators and thermoelectric coolers.The study was conducted considering the same hot alumina junction surface that receives solar radiation;however,the ef-fective surface,which corresponded to the heat flow area and had a similar area near the exposed surface,varied depending on the chosen leg geometry,thus impacting the heat flux due to the variation in thermal resistance.In the case of a solar thermoelectric generator,the Rect-leg model,having the same effective surface area,presented the lowest heat loss value resulting from convection and radiation in the heat spreader and the hot alumina plate.Under the same conditions,the Y-leg showed the highest value.The Rect-leg design generated,by using thermal and optical concentration,the highest output power of 0.028 and 0.054 W,and efficiency of 3.47%and 4.7%,respectively,whereas the Y-leg generated lower values of 0.006523 and 0.018744 W for power,and 2.83%and 2.71%for efficiency,respectively.In the case of the thermoelectric coolers,the Y-leg generated the highest temperature difference between the hot and cold sides of 67.28 K at an electric current value of 1.8 A,whereas the Rect-leg,Pin-leg and X-leg generated~66.25,~67.02 and~67.19 K at 6.1,2.7 and 2.6 A.
