Numerical modelling of transient heat transfer phenomena in a refrigerated truck body during operation

Air-conditioning and refrigeration systems are widely used in modern society to transfer thermal energy from one physical location to another. The refrigeration system for perishable food transport is one example. Compared with stationary systems, transport refrigeration systems are required to perform reliably in much harsher environment compared to stationary refrigeration systems, thus they may present lower Coefficient of Performance (COP). To investigate and improve the refrigeration system performance, good knowledge of the system behaviour is required: this knowledge can be obtained from modelling and simulation tools which offer an economic alternative to physical experiments, though a reliable model needs to be validated with experimental data. This paper presents the dynamic simulation of a refrigerated transport system, composed by the insulated body of a refrigerated van and the cooling unit, and evaluates the transient heat transfer phenomena occurring during a typical delivery mission, with particular focus on the pull down and door opening operations. Results indicate the importance of the dynamic response of the system in the correct evaluation of its thermal performance during operation.