基于系统经济优化的换热器设计

Heat Exchanger Design Based on Systematic Economic Optimization

传统换热器设计依赖于设计者的经验,通过实际操作条件要求进行选型与设计参数的调整,很少考虑设备经济性.以传热效率X和综合利润Ctotal为目标函数,基于技术经济学原理,对流道长度、换热面积及冷热进口流量设计参数进行了数值模拟.模拟研究了各参数对目标函数的影响.结果表明:传热效率随流道长度的增长而提高,并在长度大于10,m时趋于稳定;而压降与各参数变量呈指数关系;进出口流量对传热效率影响不大,但因此导致的高压降会使综合利润降低;换热面积越大,换热效果越好;根据对综合利润的分析,流量长度增加、换热面积减小会导致综合利润的降低.兼顾传热效率、综合利润值,对换热器进行了优化设计.

Traditional heat exchanger design is an iterative process relying heavily on the experience of design-ers. Usually a referential geometric configuration of the heat exchanger is chosen,and then the design parameters are adjusted according to the requirement of the actual situation. However,the traditional design may not be cost-effective for the lack of cost criteria. Based on the principle of technical economics,the heat transfer efficiency X and combined profits Ctotal were considered as the objective functions. Taken channel length,area of heat transfer and flow rate of cold and hot inlets as variables,the effect was simulated. According to the results,with the increaseof length of channel,the heat transfer efficiency increases. Once the length is greater than 10 m,it remains almostthe same. Meanwhile,the pressure drop exponentially changes with the variables. Flow rate has little effect onheat transfer efficiency,but the increase of pressure drop will lead to combined profit decline. The larger the areaof heat exchanger,the better effect of heat transfer efficiency. Besides,the increase of channel length and decrease of heat transfer area will lead to smaller combined profits. Taken the efficiency of heat transfer,and value of combined profit into consideration,the heat exchanger is optimized.