Injection performance analysis of scroll compressors with varying spiral turn configurations for electric vehicle applications: An experimental approach

This study introduces a novel approach to enhancing the performance of scroll compressors in electric vehicle (EV) heat pump systems, particularly under low-temperature conditions. Despite their critical role in EV heating systems, scroll compressors often experience reduced efficiency in cold climates. To address this issue, the research investigates the integration of vapor injection technology and the optimization of scroll compressor geometry. Eight innovative compressor configurations, varying in spiral turns count and injection port placement, are designed and analyzed. A new theoretical model of the compressor's operating cycle is developed, enabling precise simulations of performance under different conditions. The study demonstrates that increasing the number of spiral turns enhances heat generation but reduces the coefficient of performance (COP), while vapor injection technology improves heating performance by 2.4 % to 4.9 % compared to non-injection designs. To further explore the effects of design modifications, three-dimensional simulations are conducted to analyze temperature and pressure distributions at various injection port locations, revealing that compressors with three spiral turns (N = 3.0) exhibit higher internal temperatures, potentially leading to localized high-temperature accumulation near the discharge port. The theoretical model is rigorously validated through experimental testing, confirming its accuracy and providing practical insights for compressor design. The findings establish an optimal spiral turns range (N = 2.2 to N = 2.6) for maximizing heating efficiency. This research significantly contributes to the development of high-efficiency, low-temperature scroll compressors for EV heat pump systems, offering innovative solutions to enhance energy efficiency and performance in cold-climate applications.