Theoretical study and experimental verification of the behaviour of a passive conditioning system for electronic components

The paper describes the theoretical determination of the flow and the temperature distribution in a water natural circulation loop for passive conditioning of a big shelter for electronic components. A cylinder filled with phase change material in thermal connection with the inner of the shelter and with the ambient by a water natural circulation loop forms the system. The system operates in natural convection, consequently during the daytime the water flow in the exchanger is stopped because the external temperature is greater then the melting temperature. During the night the situation is reversed, thus the convective flow begins allowing the water circulating and exchanging heat with the ambient. The paper presents a simulation model which describes the flow and the temperature field of the water in the loop during the night. Moreover the theoretical values of temperature are compared with the experimental data obtained in a climatic chamber.