基于经济学观点确定换热网络传热温差

Exergoeconomic analysis of heat exchanger networks for optimum minimum approach temperature

从分析和经济学的角度提出了确定换热网络最小传热温差的方法。在基于夹点技术温焓图的基础上,把冷、热公用工程物流的基本属性同工艺物流的组合曲线一起标示于温焓图上,组成平衡组合曲线。对平衡冷、热组合曲线进行分段积分,较精确地求取换热网络传热过程的损失。以损费用代替公用工程的能耗费用作为操作费用,确定经济目标函数,用以计算最佳的传热温差。该方法为合理地降低能源消耗指明了方向,同时揭示了能量在过程系统中演变和变化的本质。

Heat exchanger networks （HENs） design for optimum minimum approach temperature was presented using exergoeconomic analysis. Cold and hot utilities were integrated with process streams into T-H plot to form the balanced composite curves based on pinch technology. Exergy consumption of heat transfer in HENs was calculated using subsection integral on balanced composite curves. Exergy consumption expense substituted the energyconsumption cost of utilities as operating cost. So the objective function based on exergoeconomics was proposed, which determined the optimum minimum approach temperature of HENs. Numerical results demonstrate the validity of the proposed approach. Some measures are helpful to decreasing energy consumption; meanwhile it reveals the energy essential of evolution and change in the process system.