Many aspects of absorption technology for heating and cooling applications have been studied at KTH since the early 80's. This includes: heat and mass transfer studies on component levels, along with overall systems analysis addressing performance, economics and environmental impacts. Today, the relevance of this research is ever-increasing. Integrating absorption technology in an energy system enables efficient utilization of the abundant resources of low-grade heat such as waste heat and solar heat. The use of these energy sources is a key to reaching a sustainable energy system. Ongoing work considers how absorption machines should be designed for optimal integration with combined heat and power technology (CHP), and district energy systems. An example is the dual function of an absorption machine in a district heating system. Here, the machine is designed to be a heat pump coupled to flue gas condensation in the winter, and a chiller generating comfort cooling out of waste heat in the summer. The cost-effectiveness of lowering the operating temperature is also evaluated as well as the operational strategies for achieving a large temperature reduction of the heat carrying fluid in the generator part – both desirable characteristics for integration with CHP and district heating. Optimization of heat exchanger surfaces, liquid/liquid and liquid/vapour, for cost reduction of these low temperature machines is also under way.
Absorption chillers, Absorption cooling, District cooling, Energy utilization, Heat and mass transfer enhancement