Applicable temperature prediction of composite heat exchanger group in construction vehicle by area-weighted modified ɛ-Ntu model

• An area-weighted model was proposed for the applicable ambient temperature (AAT) prediction of the composite multi heat exchanger system of engineering vehicle based on the modified ε-Ntu method involving j and f factors of each heat exchanger in the system. • A hydro-mechanical transmission crawler bulldozer with 220-horsepower was tested to verify the model accuracy. The bulldozer is equipped with the “3 + 1″ composite heat exchanger system, which is widely use nowadays. • The prediction modeling results and experiment results exhibited a similar trend with the maximum error below 5.10 %. • The final AAT of the tested bulldozer is confirmed at 34 °C with the proposed area-weighted modified ε-Ntu model, which is consistent with the actual operation requirement. • The proposed model might offer a rapid solution to the prediction of AAT with easy-obtaining j and f factors, and provide a reference for the related design and research. To address the harsh and variable conditions in recent years, an increasing number of construction vehicles have adopted composite heat exchanger systems. The common recognized performance prediction on a single heat exchanger might be still behind the composite heat exchanger group for its complexity. In this paper, an area-weighted model was proposed for the applicable ambient temperature prediction of the heat exchanger system based on the modified ε-Ntu method involving j and f factors of each heat exchanger in the system. Firstly, an overview of the architecture of a composite “3 + 1″ heat exchanger system were in the first row side by side and a size-matching coolant heat exchanger was placed in the rear row along the airflow direction, was presented, together with the corresponding heat transfer principle for this system. Then, the detailed prediction on the heat transfer quantity of the system was introduced based on the modified ε-Ntu method. Following that, a field experiment was conducted to validate the model correctness to the further prediction. At last, the prediction on the temperature was performed for the stableness of the current system. It is found that the predicted heat transfer quantities of four different heat exchangers, 37,687.24 W, 30,450.47 W, 3660.15 W, and 86,541.42 W under 16 °C, could secure the model duty with the maximum 5.10 % error. The applicable ambient temperature is 34 °C with a 3696.57-W coolant heat exchanger. This paper is expected to provide a scientific basis for the performance evaluation of composite heat exchanger systems for construction vehicles.