ass日本风韵熟妇pics男人扒开女人屁屁桶到爽|扒开胸露出奶头亲吻视频|邻居少妇的诱惑|人人妻在线播放|日日摸夜夜摸狠狠摸婷婷|制服 丝袜 人妻|激情熟妇中文字幕|看黄色欧美特一级|日本av人妻系列|高潮对白av,丰满岳妇乱熟妇之荡,日本丰满熟妇乱又伦,日韩欧美一区二区三区在线

Fermentation temperature is instable in the northern winter which is the bottleneck of biogas system. In order to solve this problem, a heating equipment which was a hot water heater with heat pipe with gas heating used for biogas system was developed. The distance of the heating side with heat pipe from gas stove hole, flow rate of the burning gas and average water temperature were chosen as experimental parameters. The conditions of this processing technology were optimized by the index of thermal efficiency of hot heater. The result showed that the thermal efficiency of the hot water heater reached the maximum value of 63.47% when the distance of the heating side with heat pipe from gas stove hole was 21.5cm, the flow rate of the liquefied petroleum gas was 1.01kg/h and the average water temperature was 35~45℃.