一、比较余热利用方案优劣的热力学准则 本文分析计算限于下述两类余热:第一类为余热流的来流温度T_a与质量流率m均不变,被利用后余热流直接排至环境;第二类为余热流的质量流率可以变化,而来流温度与可利用的余热流率Q_(ab)=Q(12)不变(下角ab表示余热流从状态a变至b时在换热Ⅰ中传给中间介质的热率;下角12表示中间介质自状 First, compare the advantages and disadvantages of waste heat utilization program thermodynamic criteria Analysis and calculation of the following two types of waste heat: the first type of waste heat flow temperature T_a and mass flow rate m are unchanged, the waste heat flow is used directly to the environment ; The second type is the mass flow rate of the residual heat flow can be changed, while the flow temperature and the available residual heat flow rate Q_ (ab) = Q (12) unchanged (lower angle ab said when the residual heat flow from state a to b Heat transfer to the middle of the heat medium Ⅰ heat; lower corner of 12 that the intermediate medium self-like