【摘要】 以水为工作介质,给出了表征不可逆损失的无因次熵产数Ns的计算式;并应用最小熵产原理分析了各种参数对不可逆损失的影响。结果表明:层流状态下存在一个最佳Re数使Ns值最小,影响不可逆损失和最佳Re数的主要因素是无因次入口温差τ、定义的无因次数ψ2及半径比δ。这对确定螺旋管合理的流动工况、结构参数和减小传热过程中的不可逆损失有重要意义。更多还原

【Abstract】 The formula of dimensionless entropy generation number charactering irreversible loss was obtained for water as working medium in the helical tube.Based on minimal entropy generation principle,the effect of all kinds of parameters on the irreversible loss was analyzed.The results show that in laminar condition there is an optimum Re number that can make the dimensionless entropy generation number be minimal,the irreversible loss and Re number are primarily affected by temperature difference of inlet,dimensionless number ψ2 and the ratio of radius.The method and result are virtue for determining the reasonable fluid condition,parameters of a helical tube and saving energy of heat transfer process.更多还原