基于传热和压降耦合的混合工质冷凝器结构优化

发布时间：2018-01-12 05:26

本文关键词：基于传热和压降耦合的混合工质冷凝器结构优化　出处：《高校化学工程学报》2017年01期 　论文类型：期刊论文

【摘要】：基于传热和压降的耦合作用,针对R744/R290(20/80)和R125/R290(25/75)混合工质逆流换热冷凝器建立基于熵产最小化的管长优化数学模型,并结合Cavallini凝换热性能评价指标PEI(performance evaluation index)和温度惩罚因子TTP(total temperature penalization),得到了混合工质PEI与传热系数α之间的函数关系,具体分析了管径、冷凝温度和被动压降对管长优化结果的影响。研究表明,制冷剂饱和温度降为制冷剂与壁面之间传热驱动温差的0.6倍,高压工质R744/R290(20/80)(临界温度低的工质)的PEI值更小,冷凝换热性能更优,同时小管径的冷凝器最优管长更小,且最优管长随随着冷凝温度的增大而增大,随着被动压降的增加而减小。
[Abstract]:Based on the coupling of heat transfer and pressure drop. For R744 / R290 / 20 / 80) and R125 / R290 / 25 / 75), a mathematical model of optimization of tube length based on entropy minimization is established for the counter-flow condenser. PEI(performance evaluation index and temperature penalty factor (TTP) were used to evaluate the heat transfer performance of Cavallini. Total temperature penalization. The function relationship between PEI and heat transfer coefficient 伪 is obtained, and the influence of pipe diameter, condensation temperature and passive pressure drop on the optimization results of pipe length is analyzed in detail. The saturation temperature of refrigerant is reduced to 0.6 times of the difference of the heat transfer driven temperature between the refrigerant and the wall, and the PEI value of R744 / R290 / 80 / 80 (the working medium with low critical temperature) is even smaller. At the same time, the optimal tube length of the condenser with small diameter is smaller, and the optimal tube length increases with the increase of condensation temperature and decreases with the increase of passive pressure drop.
【作者单位】：中原工学院能源与环境学院;河南工程学院土木工程学院;郑州大学土木工程学院;
【基金】：国家自然科学基金(U1504501) 河南省高校青年骨干教师项目(2014GGJS-089) 河南省高校重点科研项目(15A560014) 高端外国专家项目(GDW2016 4100039)
【分类号】：TU83
【正文快照】： 1前言在制冷空调及热泵系统中,冷凝器的性能优劣直接影响到系统的制冷、制热效果和能耗情况。传统冷凝器设计,通常依赖样机的反复制作与调试,存在周期长、费用高等缺陷,影响产品性能优化。目前,国内外对冷凝器研究的整体趋势是:基于系统目标,结合计算机仿真模拟技术,建立冷凝

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