东西轴向横置真空集热管内不同形状吸热体能量收益的研究

A STUDY ON ENERGY GAIN ON ABSORBERS WITH DIFFERENT SHAPES IN EVACUATED COLLECTOR TUBES OF EAST WEST AXIAL HORIZONTAL ORIENT

在实验测定真空集热管内不同形状吸热体表面相对太阳辐照度和涂层太阳吸收率随光线入射角变化的基础上，分析研究了玻璃罩管内平面、半圆柱和圆柱三种不同形状吸热面的能量收益因子随光线入射角变化的规律。依据晴天辐射模型，对北纬４０°、倾角４０°、朝南放置的三种不同形状吸热面在单支东西轴向横置真空集热管内的日能量收益及其年变化进行了计算和比较。结果表明，半圆柱和圆柱吸热面不论是瞬时能量收益还是年能量收益，相对于平面吸热面，其优越性不如南北轴向斜置的情况。对全年运行具有平面和半圆柱吸热面的真空集热管的最佳倾角也进行了探讨。

Based on measuring values of relative solar irradiation on absorbers with different shapes in evacuated collector tubes as well as measuring values of solar absorptivity changing with incident angles on the coating,this paper analyzed and investigated regular patterns of energy gain factors changing with incident angles for three different absorbers including flat semicylindric and cylindric absorbers in glass tubes envelope.According to the Clear Day Model,daily energy gain and its annual variation for single evacuated collector tubes of east west axial horizontal orient with three different absorbers placed in north latitude 40°,inclined angle 40° and southern orient have been calculated and compared.The results show that superiority of east west axial horizontal evacuated collector tubes with the semicylindric absorber and the cylindric absorber to the flat absorber is far less than south north axial slant evacuated collector tubes on not only instantaneous energy gain but also annual energy gain.