最近，新一代天然气发动机驱动热泵（GEHPs）被引入市场。虽然安装的装置表现异常出色，在舒适性和节省水电费方面赢得了好评，但较高的初始成本和相对较长的投资回收期影响了这项先进技术的广泛商业化。根据为美国东南部亚特兰大大都会地区所做的一项研究，GEHP的年运营成本低于由92%效率的燃气炉和季节能效比（SEER）12空调组成的基准系统。预计投资回收期约为10年，以弥补新系统和基准系统之间初始设备价格的差异。 据预测，液体溢流（LOF）回热循环概念可以简化GEHP的硬件设计，从而降低成本并提高性能。实验室测试表明，LOF将使蒸汽压缩装置的能效提高10%。此外，LOF将降低压缩机的压力比，从而提高设备的可靠性。基于假定的性能改进和成本降低，简单的回收计算表明，LOF可以大大缩短亚特兰大大都会地区改进后的GEHP的回收时间。已对改进的GEHP进行了实验室测试。本文报告了实施LOF所需的设备设计修改，以及稳态下的性能测试结果- 国情。初步冷却试验结果表明，LOF与孔板式膨胀机结合，可用于GEHP，以提高成本和性能。能效的提高取决于几个控制参数，包括适当的制冷量、选定的环境温度和系统运行条件。单位:I-PCITION:研讨会，ASHRAE交易，1998年，第104卷，pt。1A，旧金山

A new generation of natural gas engine-driven heat pumps (GEHPs) was introduced to the marketplace recently. While the units installed have performed exceptionally well and earned rave reviews for comfort and savings on utility bills, the higher initial cost and relatively long payback time have affected the wide commercialization of this advanced technology. According to a study done for the southeastern U.S. in the Atlanta metropolitan area, the annual operating cost of the GEHP is less than that of a baseline system consisting of a 92% efficiency gas furnace and a seasonal energy efficiency ratio (SEER) 12 air conditioner. The estimated payback time is about ten years to cover the difference in initial equipment price between the new and the baseline system. It has been projected that a liquid overfeed (LOF) recuperative cycle concept can simplify the hardware design of a GEHP, resulting in reduced cost and improved performance. Laboratory tests have shown that LOF would improve the energy efficiency of a vapor compression unit by 10%. In addition, LOF will reduce the compressor pressure ratio and thereby improve equipment reliability. Based on the assumed performance improvements and cost reduction, a simple payback calculation indicates LOF can reduce the payback time for an improved GEHP considerably in the Atlanta metropolitan area. Laboratory testing of an improved GEHP has been carried out. This paper reports on the equipment design modifications required to implement LOF and the results of performance tests at steady-state conditions. The preliminary cooling test results have indicated that the LOF, in conjunction with an orifice-type expander, can be applied to a GEHP for cost and performance enhancements. The improvements in energy efficiency will be dependent upon several controlling parameters, including the proper refrigeration charge, the selected ambient temperature, and the system operating condition.Units: I-P