Evaluation of methanol/activated carbons for thermally driven chillers, part II: The energy balance model

This paper describes a simple energy balance model based on static parameters to calculate the COP of an adsorption chiller. The model leads to an analytical equation using basic information about the working pair, the chiller design and the operation temperatures. A set of dimensionless key figures is derived for better understanding of the influence of physical parameters on the COP. These key figures are investigated in this paper. In contrast to absorption chillers, desorption is not an isobaric process in adsorption chillers. The influence of the path is discussed in the limits of isobaric and isothermal desorption. Furthermore, the model is applied to a set of new material data, focussingfocussing on methanol/activated carbon as the working pair. This working pair makes refrigeration below 0 °C feasible.This paper is the second of two articles about the measurement and evaluation of methanol/activated carbon for cooling purposes in adsorption chillers. The first part contains the experimental description and the thermophysical properties of methanol/activated carbon