engleski

THE POSSIBILITY OF AN ADAPTIVE CONTROL OF COOLING-DEFROSTING CYCLE DEPENDING ON FROST CONDITIONS AT THE EVAPORATOR

In the paper, an analysis of a refrigeration device operation under frost forming conditions has been performed. The results of mathematical modelling and numerical calculation of heat and mass transfer in the boundary layer have been used as a base for the calculation of an effective exchanged heat flux. Several cases with different operating conditions have been analysed and the resulting correlations for determining the optimal duration of the cooling cycle have been shown. The presented results could be used to control the device within the scope of maximising the cooling effect and reliability of a cooling energy supply. In the controlling algorithm hereunder, the starting moment of the defrosting cycle has been selected depending on real frosting conditions such as air temperature, humidity and velocity as well as temperature of the heat exchanger surface.

fin-and-tube heat exchanger; defrosting process

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