Background

In applications with a small power output range below 1000 kW as automotive vehicle and stationary electricity generation, power cycles such as the internal combustion engine ( ICE ) and gas turbine ( GT ) is used today. When discussing environmentally friendly power cycles for the future also fuel cells technology is mentioned. However, steam power cycles have many inherent physical qualities that unfold new possibilities to realize cost effective and environmentally friendly power cycle for many different small scale power output applications. Steam power cycles can be utilized as a self-contained ( stand alone ) power system offering several competitive features compared to ICE, GT and fuel cells. However, steam power is not only a competitor to ICE, GT and fuel cells but is also interesting to combine with the other power cycles and form hybrid ( Combi ) system offering high efficiency, flexibility matching electricity and heat demand , and backup facilities .
When the power output is below some 1000 KW the most proper expander type is the reciprocating piston engine and in order to implement the competitive Small Scale Steam Power ( SSSP ) cycles the old steam engine has to be updated. Novel high performance steam engine system has a potential to offer attractive SSSP for mobile as well as stationary Combined Heat and Power (CHP) applications.