Parametric analysis on the performance of a revolutionary rotary Ericsson heat pump/engine

The majority of coolers, refrigerators and air conditioners in the current energy market are based on the vapour compression cycle using HFC’s (Freon) which has detrimental environmental issues. A revolutionary mechanical heat pump/engine system utilizing the Ericsson thermodynamic cycle has been proposed to provide efficient and environmentally friendly cooling. This system consists of two pairs of independently driven rotors each controlled by a motor-generator (MG). The design is simple, scalable, and, with only four moving parts, adaptable to many applications. Continuous cycling with constant fluid compression, heat exchange, and expansion, allows a compact device with high heat pump capacity and efficiency. Computer simulation models have been developed to simulate the rotor positions based on two simple sine shaped functions. Further modelling has been conducted to predict the torque and power of the rotary Ericsson heat pump (REHP) utilizing Ericsson thermodynamic cycle. Parametric and optimization study has been conducted to evaluate a number of factors affecting the mechanical and thermal performance of the conceptually designed REHP, such as rotor geometries, parts material, working fluids, base pressure, compression ratio, temperatures, RPM etc. It has been found that the rotor size, together with compression ratio and base pressure have the largest contribution to the maximum torque required and thus the maximum power of the MG. The rotor material density however does not much affect the maximum torque which makes it possible to choose from a wide variety of materials to suit different application needs.