Dimensionnement des engins multi temperatures : calcul, methodologie, exemples, impact sur le dimensionnement.

Multi-temperature refrigerated transport equipment appeared on the market on the early 90’s. Testing methodologies were soon developed to assess their performance and measure their refrigeration capacities in different operation modes and temperature conditions. These methodologies were finally stabilized in 1998. Ten’s of units were tested since 1994 in different laboratories. The dimensioning rules were initially quite simple. Evolution were proposed and finally approved in 2011 by WP11, the technical comity in charge of the international Agreement for the Transport of Perishables goods of the United Nations (ATP). This new methodology is far more complicated and difficult to implement on the field. Everybody agreed that a tool or a soft was absolutely necessary.
The Cemafroid developed software for this purpose dedicated to help the dimensioning of the equipment by the manufacturer and to help the competent authorities to verify the dimensioning of the manufacturer. The Cemafroid soft operates all the iterative calculation required by ATP.
This paper describes the soft at its principles in line with the ATP calculation rules for multi-temperatures. Then it gives examples of equipment dimensioning and finally compares them with the dimensioning done with the former calculation rules. It is underlining the impact of the new methodology on the dimensioning of the equipment and the necessary evolution of the solutions proposed.