Impact Of Operating Conditions On Cooling Capacity For Sorption Systems Using Water As Refrigerant

The implementation of compact heat exchanger in sorption systems is a key factor to allow the development of these systems. The aim of this paper is to develop a statistical model with a design of experiment (DOE) methodology and use dimensionless number to evaluate and understand the influence of the height of refrigerant liquid and secondary fluid inlet temperature on cooling capacity of a compact pate-type evaporator for sorption systems working near vacuum pressure. For this purpose, an experimental campaign was conducted on a small adsorption test bench using 13X/water as working couple. Cooling capacities from 640 to 2000 W were measured. The DOE is a Doelhert type with two parameters: the inlet secondary fluid temperature (from 10 to 21 degrees C) and the filing level of refrigerant in the evaporator (from 6 to 24 cm). Thanks to the exploitation of the mathematical model obtained, optimal points under different constraints were found. A maximum cooling capacity of 2021 +/- 75 W in the entire experimental field was predicted for a secondary fluid inlet temperature of 25 degrees C and a height of liquid level of 19.2 cm. Bond number and modified Jacob number per the ratio P-sat/P-triple were analyzed. The dimensionless numbers are correlated to the cooling capacity as a first step for designing compact plate-type evaporator for adsorption systems using water as refrigerant.