Vapor injection technology is a promising method to improve the performance of heat pump systems on electric vehicles. In this work, an experimental study on a low pressure ratio vapor injection scroll compressor was carried out under low ambient temperature conditions. Comparative experiments were conducted for various injection pressures, compressor speeds, and evaporation temperatures. The typical flow and heat transfer characteristics were obtained and analyzed, especially the compressor volumetric efficiency and compressor efficiency. The results showed that the heating performance was improved and discharge temperature was reduced with the increasing injection pressure at a higher compressor speed and a lower evaporation temperature. The volumetric efficiency and compressor efficiency both decreased with the increasing injection pressure. The maximum heating capacity could increase by 16% and the maximum discharge temperature reduction would reach 8 °C for the vapor injection process compared with non-injection process under the evaporation temperature of -22 °C. Furthermore, a semi-empirical model with correlations of volumetric efficiency and compressor efficiency was developed. The results were validated and showed a reasonable agreement with experimental results.

蒸汽喷射技术是提高电动汽车热泵系统性能的一种很有前景的方法。在这项工作中，在低环境温度条件下对低压比蒸汽喷射涡旋压缩机进行了实验研究。针对不同的喷射压力、压缩机速度和蒸发温度进行了对比实验。获得并分析了典型的流动和传热特性，特别是压缩机容积效率和压缩机效率。结果表明，在较高的压缩机转速和较低的蒸发温度下，随着喷射压力的增加，加热性能提高，排气温度降低。容积效率和压缩机效率都随着喷射压力的增加而降低。在-22℃的蒸发温度下，与非注入工艺相比，蒸汽注入工艺的最大加热能力可提高16%，排放温度最大降低可达8℃。此外，还开发了具有容积效率和压缩机效率相关性的半经验模型。结果得到验证并显示出与实验结果的合理一致性。