CFD model of vehicle condenser

Ing. Michal Schmid

Doctoral thesis

Abstract:

The AC condenser plays a vital role in HVAC systems (Heating Ventilating Air Conditions). In vehicles, it is typically located within a cooling pack, alongside other heat exchangers. The dissipation of heat from the AC condenser directly affects surrounding components. Therefore, accurate modeling of heat transfer between the refrigerant and air is crucial for vehicle development, especially nowadays for battery electric vehicles. The proposed model enhances the spatial distribution of heat transfer, resulting in improved air temperature predictions. The proposed model is based on the well-known and established ? - NT U approach and iterative takes into account the appropriate relation according to the refrigerant phase during the condensation process occurring in the condenser. Additionally, the approach reduces the amount of required input data and relies on directly measured condenser characteristics, leading to more generic approach. In the thesis, a dedicated test equipment was developed for input data measure ment and model verification. The proposed model was tested under two distinct conditions and compared with measurements. The model exhibited good agreement with the measurements in predicting refrigerant inlet and outlet temperatures, as well as relatively good agreement in air outlet temperature prediction. Furthermore, additional development tasks were identified as well.

Abstract:

The AC condenser plays a vital role in HVAC systems (Heating Ventilating Air Conditions). In vehicles, it is typically located within a cooling pack, alongside other heat exchangers. The dissipation of heat from the AC condenser directly affects surrounding components. Therefore, accurate modeling of heat transfer between the refrigerant and air is crucial for vehicle development, especially nowadays for battery electric vehicles. The proposed model enhances the spatial distribution of heat transfer, resulting in improved air temperature predictions. The proposed model is based on the well-known and established ? - NT U approach and iterative takes into account the appropriate relation according to the refrigerant phase during the condensation process occurring in the condenser. Additionally, the approach reduces the amount of required input data and relies on directly measured condenser characteristics, leading to more generic approach. In the thesis, a dedicated test equipment was developed for input data measure ment and model verification. The proposed model was tested under two distinct conditions and compared with measurements. The model exhibited good agreement with the measurements in predicting refrigerant inlet and outlet temperatures, as well as relatively good agreement in air outlet temperature prediction. Furthermore, additional development tasks were identified as well.

Keywords

AC Condenser, CFD, Heat Transfer, Measurement

Language used: Czech

Date on which the thesis was submitted / produced: 31. 8. 2023

Thesis defence

• Date of defence: 13. 11. 2023
• Supervisor: doc. Ing. Petr Tomek, Ph.D.

University of Pardubice

Faculty of Transport Engineering

Doctoral programme / field:
Technique and Technology in Transport and Communications / Transport Means and Infrastructure: Transport Means