Thermodynamic bounds for food deep chilling tray tunnel operation

In this paper a thermodynamically guided intensification method on tray tunnels for food deep chilling is presented. Two indicators of the performance of the system are used: the exergy power and the destruction of specific exergy. The objective function corresponds to the maximization of the exergy power and the minimization of the specific exergy destruction. Exergy has the main advantage to take into consideration both the food mass flow rate and its output temperature level. The food mass flow rate stands for its quantity whereas the temperature level represents its quality. An endoreversible model is also presented in conjunction with a simple mathematical description of the refrigeration cycle internal irreversibilities. A numerical investigation against operation variables permits to find the so-called intensification zone that defines bounds for food mass flow rate and output temperature as well as for the refrigeration cycle evaporator temperature.