Design of a reversible heat pump/organic Rankine cycle unit for a renewables-based trigeneration system

Reversible heat pump/organic Rankine cycle (RHP/ORC) systems have been lately brought to the forefront of two main applications. The first involves the provision of useful heating or cooling and the exploitation of external heat sources for power production, whereas the second deals with energy storage, where heat is primarily produced to be stored and then utilized for power generation to compensate the mismatch between generation and demand. In the present study, the design and the seasonal performance evaluation of a micro-scale, renewable energy-based trigeneration system having an RHP/ORC unit at its core are presented, where the two aforementioned concepts can be combined. The system operates either as a heat pump for low-temperature heating driven by solar heat and for cooling coupled with an adsorption chiller in a cascade configuration or as a stand-alone chiller, or as an ORC valorizing solar and/or biomass heat up to 120 °C. The design of the prototype system is hereby presented, including system modeling and working fluid selection, system architecture design and equipment sizing. Based on the simulations, the flexible design of the system allows for efficient performance under the main identified operating modes, reaching a seasonal energy efficiency ratio (SEER) and seasonal coefficient of performance (SCOP) of 3.63 and 4.25 for an average climate, as well as a maximum nominal ORC efficiency up to 5.90%.      «

Reversible heat pump/organic Rankine cycle (RHP/ORC) systems have been lately brought to the forefront of two main applications. The first involves the provision of useful heating or cooling and the exploitation of external heat sources for power production, whereas the second deals with energy storage, where heat is primarily produced to be stored and then utilized for power generation to compensate the mismatch between generation and demand. In the present study, the design and the seasonal pe...     »