空调和热泵研究的三个主要目标是提高能效、降低成本和降低环境影响。空气-制冷剂热交换器是此类系统中的关键部件。在这些换热器的设计和优化上花费了大量精力。众所周知，较小的通道尺寸可以显著提高其性能。最近的分析表明，通过采用小于2 mm（0.08 in）的管外径，在尺寸、重量、制冷剂加注和传热方面有很大的改进潜力。本文提出了一种适用于水力直径小于2mm（0。 08英寸）。设计优化的目标是开发比当前最先进设计至少紧凑20%的热交换器设计。对于水力直径如此之小的管道，公开文献中没有现成的空气侧性能经验关联式。因此，采用了基于计算流体力学（CFD）的关联式，该关联式适用于低密度的裸管束和翅片管。基于CFD的模型在用于设计优化之前，会根据实验数据进行验证。采用多目标遗传算法（MOGA）的近似辅助优化（AAO）方法寻找超越当前状态的最优设计- 在尺寸、性能和制冷剂加注方面都是最先进的微通道热交换器。研究了空气-水散热器和空气-制冷剂冷凝器的各种设计。所研究的几何结构可能比目前最先进的热交换器至少好20%。引用:ASHRAE论文:2015年ASHRAE年会，伊利诺伊州芝加哥

The three main objectives of air-conditioning and heat pump research are to improve energy efficiency, reduce cost and lower environmental impact. Air-to-refrigerant heat exchangers are key component in such systems. A great deal of effort is spent on the design and optimization of these heat exchangers. It has been well known that smaller channel sizes can significantly improve their performance. Recent analyses demonstrate great potential for improvement in terms of size, weight, refrigerant charge and heat transfer by employing tube outer diameters below 2 mm (0.08 in). This paper presents a comprehensive approach for the design optimization of heat exchangers with small hydraulic diameters below 2 mm (0.08 in). The goal of the design optimization is to develop heat exchanger designs that are at least 20% more compact than the current state of the art designs. Empirical correlations for air side performance are not readily available in open literature for tubes with such small hydraulic diameters. Hence, Computational Fluid Dynamics (CFD) -based correlations developed for bare-tube bundle and fin-and-tube, with low find densities, are used. The CFD based models are validated against experimental data before using them for design optimization. Approximated Assisted Optimization (AAO) method, using Multi-Objective Genetic Algorithm (MOGA) is employed to find optimum designs that surpass current state-of-the-art Micro-Channel heat exchangers in size, performance and refrigerant charge. Various designs for air-to-water radiators and air-to-refrigerant condensers are investigated. The investigated geometries have the potential to be at least 20% better than the current state of the art heat exchangers.