The objective of this paper is to develop a more efficient control logic via investigations of the dynamic characteristics of a CO₂ heat pump for heating vehicles. A transient thermodynamic model was set up using Modelica language, and the PID controller was used for a stable cabin environment. The influence of the discharge pressure and airflow rate on the dynamic characteristics, including the dynamic COP, the heating capacity and the return air temperature, were investigated and analyzed. Moreover, the comprehensive COP during the dynamic process was calculated and analyzed. Experimental data from a sample vehicle were used to validate the accuracy of the model. Results showed that the real-time COP decreased quickly at the initial starting process but then increased gradually to the stable value. The heating capacity and the return air temperature had the reverse tendency. With the increase of the discharge pressure and airflow rate, the parameters of COP, the heating capacity and the return air temperature fluctuated less heavily and reached a stable value more quickly. Improved understanding of the dynamic performance can support development of more efficient control logic.

本文的目的是通过研究CO ₂的动态特性来开发更有效的控制逻辑。用于加热车辆的热泵。使用Modelica语言建立了瞬态热力学模型，并将PID控制器用于稳定的机舱环境。研究和分析了排气压力和风量对动态特性的影响，包括动态COP，热容量和回风温度。此外，还对动态过程中的综合COP进行了计算和分析。来自样本车辆的实验数据用于验证模型的准确性。结果表明，实时COP在初始启动过程中迅速下降，但随后逐渐上升到稳定值。加热能力和回风温度具有相反的趋势。随着排气压力和风量的增加，COP的参数，加热能力和回风温度波动较小，并更快地达到稳定值。更好地了解动态性能可以支持开发更高效的控制逻辑。