Design considerations for an Ericsson engine equipped with high-performance gas-to-gas compact heat exchanger: A numerical study

Abstract

A new simulation model is presented for the simulation of the open cycle Ericsson engine operation on a crank-angle basis. The model simulates the compressor and expander operation as well as their interactions with a compact gas-to-gas heat exchanger selected from the literature based on its high heat-transfer-area-to-volume ratio. Hot gases passing through the hot side of the exchanger are the heat source that heats the compressed air, which is considered the working gas. The analysis considers both sides of the heat exchanger. Factors such as pressure drops in the air and gas streams, free-flow areas, heat transfer coefficients, heat exchanger effectiveness and heat transfer rate are considered to determine the engine performance. These factors guide the threefold numerical investigation presented herein. The effects of heater geometry and configuration (single- or multi-passing) are first analyzed and elucidate the importance of gas-side pressure drop. Next, the effect of the heat exchanger size is considered that highlights the importance of heat transfer areas and heater pressure fluctuations that affect the work produced. Finally the effect of heat source temperature on the engine performance is determined. All trends observed are analyzed and explained on a crank-angle basis, to elucidate the essential variables that link the overall engine performance to the physical phenomena evolving in the devices.