Isobaric Expansion Engines–Compressors: Thermodynamic Analysis of Multistage Vapor Driven Compressors

Isobaric expansion (IE) engines can directly convert heat into mechanical energy, making them particularly attractive for applications such as vapor-driven pumps and compressors. A recent initial assessment investigating the utilization of IE reciprocating compressors has revealed that vapor use efficiency is inherently low in case simplest direct-acting compressor designs. Based on this analysis, it was anticipated multistage compression offer significant advantages Therefore, paper aims to conduct a comprehensive analytical thermodynamic analysis direct The considers processes without intercooling with compressed gas between stages. findings demonstrate that, compression, benefits are superior those known conventional processes. Multistage not only reduces work temperature elevation but, more importantly, mitigates adverse effects driving vapor, thereby enabling substantial improvement efficiency. Furthermore, total volume engine experiences decrease an increasing number Consequently, under specific process parameters, overall dimensions engine-compressor system may also stages increases. results opportunities energy savings energy-intensive by replacing electrical readily available low-grade sources (<100 °C). Such include hydrogen, air, ethylene at high pressure.