Alkan Alpaslan
Department of Mechanical Engineering, Sakarya University of Applied Sciences, Sakarya, 54187, Turkey.
Heliyon. 2024 Aug 25;10(17):e36719. doi: 10.1016/j.heliyon.2024.e36719. eCollection 2024 Sep 15.
This study aimed to investigate the effect of changing the indoor unit air flow rate on the performance of an automobile heat pump with a suction line heat exchanger. Using a four-way valve, the automotive heat pump system was developed by reversing the refrigerant direction in the automobile air conditioning system, excluding the compressor. A suction line heat exchanger was added to the test system to enhance heat transfer between the liquid and suction lines of the automotive heat pump system. Performance comparisons were first performed for R134a and R1234yf by disabling the suction line heat exchanger. Then, the suction line heat exchanger was activated for R1234yf, and the tests were repeated. Performance comparisons were made for two different compressor speeds and three different indoor unit airflow speeds. It was found that using the heat exchanger in R1234yf operations improved the heating capacity, compressor discharge temperature and coefficient of performance by approximately 1.8 %, 5.1 % and 5.9 %, respectively. The heating capacity of the heat pump system using R134a, R1234yf, and R1234yf with the suction line heat exchanger was determined to be in the range of 2.46-3.29 kW, 2.35-3.04 kW, and 2.39-3.11 kW, respectively. An increase in the airflow speed of the indoor unit from 1.4 m s to 3.2 m s resulted in an average decrease of approximately 12.3 % in the compressor discharge temperature. In contrast, the heating capacity and coefficient of performance increased by approximately 11.8 % and 14.4 % on average, respectively, for R1234yf operations with the heat exchanger. This study revealed that by optimizing the air flow rate in the R1234yf heat pump system with a suction line heat exchanger, improvements in the heating capacity and coefficient of performance can be achieved, thus providing better thermal comfort in the passenger compartment.
本研究旨在探究改变室内机空气流速对带有吸气管路换热器的汽车热泵性能的影响。通过四通阀，在汽车空调系统中（不包括压缩机）反转制冷剂流向，开发了汽车热泵系统。在测试系统中添加了吸气管路换热器，以增强汽车热泵系统液体管路和吸气管路之间的热传递。首先，通过禁用吸气管路换热器，对R134a和R1234yf进行性能比较。然后，对R1234yf启用吸气管路换热器，并重复测试。针对两种不同的压缩机转速和三种不同的室内机空气流速进行了性能比较。结果发现，在R1234yf运行中使用换热器分别使制热能力、压缩机排气温度和性能系数提高了约1.8%、5.1%和5.9%。使用R134a、R1234yf以及带有吸气管路换热器的R1234yf的热泵系统的制热能力分别确定为在2.46 - 3.29kW、2.35 - 3.04kW和2.39 - 3.11kW范围内。室内机空气流速从1.4m/s增加到3.2m/s，导致压缩机排气温度平均降低约12.3%。相比之下，对于使用换热器的R1234yf运行，制热能力和性能系数平均分别提高了约11.8%和14.4%。本研究表明，通过优化带有吸气管路换热器的R1234yf热泵系统中的空气流速，可以实现制热能力和性能系数的提升，从而为乘客舱提供更好的热舒适性。
