The modelling of air supply system efficiency in refrigerated vehicles

Abstract

Inadequate air circulation within refrigerated truck chambers is one of the main causes of unsuitable road transport of perishable goods under controlled temperatures. An accurate understanding of indoor air motion is crucial to improving the cold conditions as well as increasing the energy efficiency of mechanical and electrical systems. This paper presents a computational model to predict the velocity, temperature and relative humidity fields in refrigerated truck chambers. The model consists of a computer procedure, in which the general equations describing the airflow pattern and the heat/mass transfer in a refrigerated room are solved using the finite volume method. The computer model was experimentally validated by measurements taken from a reduced-scale model designed to provide similarity with a prototype. The computational model was applied to calculate the cold quality, for example the temperature distribution, provided by different types of air supply systems used in compartments of long-haul vehicles. The results of the numerical solutions demonstrate how the model can be profitably used in practice to study and develop the design of refrigerated chambers.