Chapter 10 - Adsorption Refrigerators and Heat Pumps

Abstract

This chapter focuses on carbon adsorbents and their use in refrigerators and heat pumps. An indication to the range of coefficient of performance (COPs) that can be expected and the influence of the type of carbon used can be obtained by modeling the performance of carbons with a range of adsorption parameters. There is international interest in the use of active carbons within adsorption cycles to provide refrigeration or heat pumping. The benefits of heat-driven cycles range from reduction in primary energy demand within the developed counties to the ability to operate away from grid electricity supplies in developing countries. Adsorption cycles have proven to be technically feasible. The challenge is to make machines that are cost effective, which means that they must be efficient and of high power density. This requires the use of adsorbents that have both, optimized porosity characteristics and may be integrated into systems with high levels of heat transfer intensification. Heat-driven cycles for cooling or heat pumping can have energy saving and environmental benefits. There are also niche applications in developing countries or remote areas. Adsorption cycles using active carbons are one of a number of approaches that might be economically viable.