基于PV/T的家庭热电联供系统设计与分析

Design and analysis of home cogeneration power and heat system based on PV/T

为减少PV/T家用系统的初期投入成本和提高系统运行时的综合效率,采用改进的灰色斜率关联度方法分析了管板式光伏光热一体化系统热效率的影响因素,提出了可根据家庭用热量和本地区域的气象数据来优化PV与PV/T的容积配比的计算方法,并根据杭州环境条件,建立了用于4~5口之家的家用热电联供双水箱仿真系统进行全年运行分析。以综合效率和生产的可用总能量为优化目标,分析了介质流量通量、预热水箱容积对系统能量转换性能的影响。进而,提出系统采用基于辐照量和PV/T循环介质进出口温度差值为控制参数的变流量运行方式,使得系统比定10 kg/(h·m2)流量运行方式能量收益提高了9.5%,比单纯的采用辐照量控制方式能量收益提高了3.2%。采用变储水量控制方式,依靠水箱温度差值实时控制预热水箱液位,与定容水箱相比,综合能量收益增加12.1%。

To reduce the initial investment cost of the PV/T household system and enhance the overall efficiency of the system during operation, an improved gray slope correlation method is proposed to analyze the influence factors of the thermal efficiency of the tube-sheet photovoltaic thermal system. The calculation method of the volume ratio of PV and PV/T is optimized by the domestic heat and the meteorological data of the local area. According to the environmental conditions in Hangzhou, a dual water tank simulation system combined heat and power for 4~5 members household is established by the dynamic simulation software TRNSYS, which has been verified and analyzed for the whole year of operation. The influences of the flux of medium and the volume of preheating water tank on the energy conversion performance of the system are analyzed. Furthermore, the variable flow rate operation mode is proposed according to the control parameters of the radiation dose and the PV/T circulating medium inlet and outlet temperature difference. In this way, the energy return of the system in the 10 kg/(h·m2) flow rate operation mode is increased by 9.5%, which is 3.2% higher than that of the radiation dose control mode. The variable water storage control method is utilized to control the liquid level of the preheating water tank in real time depending on the temperature difference of the water tank. Compared with the constant capacity water tank, the comprehensive energy income is increased by 12.1%.