线性液浸聚光光伏冷却系统流动与传热性能研究

发布时间：2018-04-15 08:10

  本文选题：聚光光伏 + 液浸冷却　； 参考：《天津大学》2014年博士论文

【摘要】：聚光光伏（CPV）发电技术能够有效的提高光伏系统发电效率，降低光伏系统发电成本，近年来越来越受到人们的重视。但是，如何有效地实现聚光太阳电池的冷却是聚光光伏发电系统设计中的一个难点。针对传统聚光光伏冷却方式的不足，提出把直接接触式液浸冷却技术用于聚光光伏系统，并以线性聚光光伏为应用实例，建立了线性液浸聚光光伏冷却系统，从如下方面对其性能进行了实验研究和模拟分析。 1、研究了二甲基硅油液膜厚度对太阳电池电性能的影响。结果表明：与无液浸液体时电池电性能相比，一定厚度的薄液膜液浸能够提高聚光硅电池和聚光三结砷化镓电池的电性能；但电池正面有液浸液体存在时，电性能随液膜厚度的增加而下降，因此较薄的电池正面的液膜厚度有利于电池电性能的提高。 2、设计了线性条形平面镜聚光系统，通过几何关系推导得出：聚光器相邻镜片互不遮挡时的最小安装间距随镜片位置角和阳光入射角的增大而增大，当阳光入射角和接收器安装角度均为45°时，最小安装间距为镜片宽度的1.414倍；通过实验测量得出由24片镜片组成的聚光器原型的聚光比为12.90X。 3、设计了矩形窄缝流道接收器，对其性能实验研究表明：聚光比为9.61X、太阳直射辐照度（DNI）920W/m2、硅油进口15℃条件下，当接收器电池段雷诺准数Re范围在1671~8359时，组件平均温度31~20℃，对流传热系数280~1000W/(m2K)；经270天二甲基硅油长期液浸后聚光硅电池电性能没有发生衰减。 4、建立了矩形窄缝流道接收器的数值模型，，模拟分析表明：电池组件最优安装位置为流道高度方向上的中间位置，接收器进、出口段长度对电池温度影响不大，流道高度越小越有利于获得好的传热性能，但流动阻力也越大，流道的优化高度为10mm；通过拟合分析得到了接收器对流传热系数和摩擦系数关联式。 5、设计了用于液浸液体冷却的二甲基硅油-甲醇物系液液直接接触相变换热实验，实验结果表明：升液管轴向温度随高度增加呈先降低然后趋于稳定的趋势，升液管体积传热系数能够达到22~34kW/(m3K)，平均气含率能够达到0.05~0.5，此气含率范围内，以甲醇蒸气气提为推动力的条件下，在具有优化结构的矩形窄缝液浸接收器中能够实现硅油在接收器电池段Re范围在1500~7500。
[Abstract]:In recent years, more and more attention has been paid to the technology of concentrated photovoltaic (CPV) generation, which can effectively improve the efficiency of photovoltaic system and reduce the cost of photovoltaic system.However, how to effectively realize the cooling of concentrated solar cells is a difficult point in the design of concentrated photovoltaic power generation system.Aiming at the shortage of traditional condensing photovoltaic cooling method, the direct contact liquid immersion cooling technology is put forward for the concentrated photovoltaic system. Taking linear concentrated photovoltaic as an application example, a linear liquid-immersed photovoltaic cooling system is established.Experimental research and simulation analysis of its performance are carried out in the following aspects.1. The effect of the thickness of dimethyl silicon oil film on the electrical properties of solar cells was studied.The results show that compared with the battery without liquid immersion, a certain thickness of thin liquid film liquid immersion can improve the electrical performance of the condensed silicon battery and the condensed trijunction GaAs battery, but when the liquid immersion liquid exists on the front of the battery,The electric performance of the battery decreases with the increase of the film thickness, so the thin film thickness on the front of the battery is beneficial to the improvement of the electric performance of the battery.2. The linear strip plane mirror condensing system is designed. Through the derivation of geometric relation, it is concluded that the minimum installation distance increases with the increase of lens position angle and sunlight incidence angle when the adjacent lenses of the concentrator are not occluded.When the incidence angle and the installation angle of the receiver are both 45 掳, the minimum mounting distance is 1.414 times of the width of the lens, and the ratio of the condenser made up of 24 lenses is 12.90X.3. The rectangular narrow slit channel receiver is designed. The experimental results show that the average temperature of the receiver is 3120 鈩

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