Design, Modeling and Performance Optimisation of a Reversible HP-ORC Prototype

Building is one of the economical sectors where solutions are available to significantly reduce energy consumption and greenhouse gases emissions. Among other, heat pumps offer promising perspectives to provide energy-efficient space and sanitary hot water heating in many applications. This paper presents an innovative system comprising a heat pump connected to a solar roof and a geothermal heat exchanger. This heat pump is also able to invert its cycle and operate as an ORC. By using the whole rooftop (hereunder called “absorber”) as a heat source, a large amount of heat is generated throughout the year. This heat is used in priority to cover the building annual heating needs and the surplus heat generated during the summer is utilized to generate electricity in the so-called HP/ORC module. The same module can be used during winter as an efficient heat pump which radically reduces the complexity of the total system. The main advantage of the proposed technology is due to the reversibility of scroll machines, which have proven to operate efficiently both as compressor and as an expander in lab testing.