Development and validation of a dynamic thermal model of a minibus using TRNSYS

[EN] The current paper presents a dynamic thermal model of a vehicle including two thermal zones, one for the front region (driver) and one for the back (passengers). The model, developed in TRNSYS, is able to predict the cabin¿s thermal behaviour under variable ambient temperatures and solar radiation. A minibus was used to validate the model using experimental data for ambient temperature, solar radiation and the indoor temperature of a minibus parked both inside and outside a garage in Torino (Italy). The proposed model accurately reproduces the warm-up and cool-down of the cabin. In addition, the model has been used to calculate the cooling load of the cabin during a summer day, and to quantify the thermal loads under variable ambient conditions. In future work, the model will be used to predict the dynamic performance of the A/C system in an urban driving cycle and to optimise the compressor control strategy.Daniela C. Vásconez-Núñez acknowledges the financial support provided by the CONVOCATORIA ABIERTA 2013-SEGUNDA FASE program, which was funded by the SENESCYT (Secretaría Nacional de Educación Superior, Ciencia, Tecnología e Innovación) (Grant No 2014-AR3R7463) of Ecuador.Vásconez-Núñez, DC.; Gonzálvez-Maciá, J.; Corberán, JM.; Payá-Herrero, J. (2018). Development and validation of a dynamic thermal model of a minibus using TRNSYS. International Journal of Vehicle Design. 77(1/2):87-107. https://doi.org/10.1504/IJVD.2018.098272S87107771/

Analysis of the Thermal Behavior of a Vehicle Cabin Using a Dynamic Thermal Model

This work analyzes the thermal behavior of a vehicle cabin by using a dynamic thermal model, which allows to accurately reproduce the vehicle interior temperature under different external environmental conditions. The thermal model considers heat transfer through the glazed and opaque surfaces of the vehicle using the energy balance method. It considers changes in weather conditions, vehicle geometry, body construction characteristics, types of opaque and glazed surfaces, and existing thermal loads. Experimental tests (with and without solar radiation) were carried out to validate the dynamic thermal model. The model predicts the temperature variations of the air inside the vehicle cabin. The results showed a maximum variation of 1.38 K without solar incidence and 3.78 K with solar radiation. Keywords: dynamic thermal model, vehicle, heat balance, thermal load. Resumen El objetivo principal del presente trabajo fue analizar el comportamiento térmico de la cabina de un vehículo utilizando un modelo térmico dinámico, que permite reproducir de manera precisa el comportamiento de la temperatura interior del vehículo bajo distintas condiciones ambientales externas. El modelo térmico considera la transferencia de calor a través de las superficies acristaladas y opacas del vehículo utilizando el método de balance de energía, para lo cual se toman en cuenta los cambios en las condiciones climatológicas, la geometría del vehículo, las características constructivas de la carrocería, tipos de superficies opacas y acristaladas y las cargas térmicas existentes. Se realizaron ensayos experimentales (con y sin radiación solar) para validar el modelo térmico dinámico. El modelo permite reproducir las variaciones de la temperatura del aire interior de la cabina del vehículo. Los resultados obtenidos muestran una variación máxima de 1.38 K, sin incidencia solar y 3.78 K con radiación solar. Palabras Clave: modelo térmico dinámico, vehículo, balance de calor, carga térmica