Experimental analysis of a transfer function for the transient response of an evaporator in an absorption refrigeration GAX system

The absorption refrigeration systems (ARS) are highly non-linear, therefore presents oscillations on the responses of its components. The physical analysis of these systems is complex, particularly the transitory response. This paper presents the prediction response of an evaporator for an ARS GAX when occurs a modification in the refrigerant mass flow rate at the evaporator inlet section; this is obtained by means of a transfer function in order to determinate the cooling load and improve the stabilization time for different operation conditions. Different control instruments have been installed in different sections of GAX system in order to obtain an operational stability and carried out the theoretical and experimental analysis. The theoretical results show a close tendency with experimental data, errors below ±2.5% are found. The results obtained between the heat load and the refrigerant mass flow rate at the evaporator will be used to design a control algorithm in order to obtain a complete autonomy system.