文档介绍：重壅奎堂堡主堂垡笙奎蔓茎塑至
AB STRACT
Using the knowledge bustion,heat transfer,fluid dynamics,orthogonal experiment and data processing theory,this paper gave a relatively detailed analysis on bustion and thermal characteristics of fore—balanced instantaneous gas water heater,some author’S standpoints were concluded and gave proposals on the heat enhancement of the instantaneous gas water heater.
At first,by the theory knowledge and experimental data,the author gave a detailed analysis on the heat transfer of fored-balanced instantaneous gas water heater, pointed out some characteristics of it and drew the following concludes:the heat
exchange between fume and water takes place at two places---bustion chamber and the heat conventional heat transfer between the血me and the wall bustion chamber is the major one and it’S ratio is about 30 percent,the radiation heat transfer between them is minor Fume’s flow in the heat exchanger is in low Reynolds heat exchange coefficient of fume—side is low,whose average
value varies little谢血the gas flow and heat exchange of water in the coil pipe is always in the entrance region whose heat exchange is greater than in the fully developed region,but it is very difficult to calculate the heat exchange coefficient between the water and the coil pipe the heat exchanger,the heat
exchanged in the first row of the coil pipe takes accost about 65 percent,which is
caused by the first row’s different heat exchange mechanics from the regard of the heat exchange enhancemen_L the author proposed that increase the distance between the fin tip and the first pipe properly,which is assisting of raise the
Reynolds number of the flow,and transfer the round-·shaped pipe to ellipse--shaped
pipe.
Through the orthogonal experiments,the author found out the major factor affecting bustion and thermal characteristics from the gas pressure,water flow, air-inlet area and fume—exhaust author used