Organic Rankine Cycles Combined with Thermochemical Heat Transformers to Enhance the Power Output from Waste Heat

摘要

The conversion of waste heat into electricity in organic Rankine cycles (ORCs) is often limited by theincomplete utilization of the heat source due to the lack of adequate heat sinks below the pinch point. In thiscontext, low temperature thermochemical sinks could provide new opportunities of heat integration, whichhave been largely overlooked until now. This study investigates the coupling of organic Rankine cycles withchemical heat pumps (i.e. thermochemical heat transformers). By taking advantage of the pressure dependenceof the chemical equilibrium, a low grade heat source drives an endothermic reaction, leading the productionof higher temperature heat source (heat upgrade) through an exothermic reaction. The upgraded heat can thenbe converted to power. Different chemical compounds and integration schemes have been investigated tooptimise the ORC performance. The proposed integrated system improves by 7.5% the power output of anoptimized ORC.