Heat Transfer and Simulation for Hybrid Photovoltaic/Thermal Solar Energy Conversion Systems.

太阳能最有效的利用方法之一是同时利用太阳光和太阳热能，如光伏/热集热器（PV/T集热器）。从这个角度来看，世界上建立了使用各种pv集热器的系统。在这些集热器中，太阳能电池被设置在一个吸收器上收集太阳能热能。因此，尽管太阳能电池的温度低于仅使用太阳能电池板时的电池温度，但太阳能电池的温度会上升到使用热能所需的温度。为了在标准条件下保持电池的转换效率，有必要将电池保持在较低的温度下。在本研究中，通过火用分析对PV/T集热器获得的电能和热能进行评估。在此基础上，提出了不降低电池转换效率的太阳能收集方法。此外，本文还试图对层流的上加热下冷却壁组合矩形管道的传热问题进行基本研究，该管道的上宽壁面以恒定的热流通量加热，而另一宽壁面则以恒定的温度冷却。结果表明：(1)对于换热面换热系数，消除了上下壁面温度和风管倾角对换热系数的影响，提高了换热系数。(2)对于风管焓和上壁温度，内部自然对流增加了上壁受热比和风管倾斜角的影响。(3)对于速度剖面，上下壁温差和风管倾角对上侧速度的影响较大。

One of most effective utilization methods of solar energy is to use simultaneously the sunlight and solar thermal energy such as Photovoltaic/Thermal collector(PV/T collector). From such a view point, systems using various kinds of P V collectors were constructed in the world.In these collectors, solar cell are set up at an absorber collecting solar thermal energy. Therefore, temperature of solar cell increases up to the desirable temperature of thermal energy use, although it is lower than the cell temperature when using only solar cell panel. For maintaining cell conversion efficiency at the standard conditions, it is necessary to keep the cell at lower temperature.In this study, electric and thermal energy obtained from PV/T collector is evaluated by exergy analysis. Based bn this evaluation, the method of not to decrease cell conversion efficiency with collecting solar thermal energy was proposed in this paper.In addition to, this study is attempt to present basic information concerning a heat transfer problems on rectangular duct combined with a upper heating and lower cooling wall for laminar flow, suffering from heating with a constant heat flux through its upper broad wall while the another wall being cooling with a constant temperature.The following results have been obtained : (1)For heat transfer coefficient of heat transfer surfaces, the influence of temperature between upper and lower wall and duct tilt angles are cleared as to increase that. (2)For duct enthalpy and upper, wall temperature, the influence of heating ratio to upper wall and duct tilt angles are increased by internal natural convection. (3)For velocity profile, the influence of temperature difference between upper and lower wall and duct tilt angles are affected to upper side velocity.