A review of Stirling-engine-based combined heat and power technology

Technologies for sustainable heat generation in food processing

“…For example, Stirling engines have been reported to run on wood chips, driven by a gasifier that converts the chemical compounds into a combustible mixture of gases (syngas). These product gases are subsequently transported in a combustion chamber and combusted at temperatures of around 1200 • C. The exhaust gases generated during this process drive the Stirling engine and can be used for cogeneration purposes (Schneider et al, 2020;Zhu et al, 2021). Another approach is to utilize solar energy by coupling a solar dish with a Stirling engine.…”

“…In turn, the mechanical work can be used to produce electrical energy. Because most engine types have an efficiency of around 20%–40% (i.e., this amount is transformed into work from the input energy) (Table 1), there is a great potential to utilize the remaining energy as a heat source in cogeneration installations (Mikalsen, 2011; Zhu et al., 2021). A major advantage is that engines are a mature technology with many improvements that have been implemented over the last century and engine technology has a widespread service community with companies all over the world.…”

“…First, the gas undergoes an isothermal expansion that is caused by an external heat source, letting the gas expand, followed by an isochoric (constant volume) heat removal. Subsequently, the gas is contracted and heat is released under isothermal conditions, followed by an isochoric heat addition (Zhu et al., 2021). This mechanism already reveals the main advantage of Stirling engines: no internal combustion is needed.…”

“…The exhaust gas is used to preheat the incoming air that goes into the combustor and is further transported into a second heat exchanger that increases the temperature of recirculating water coming as cooling water from the Stirling engine. This water is subsequently used for heating purposes (Zhu et al., 2021). However, Stirling cogeneration systems are not as developed as their internal combustion counterparts and most systems released to the market have not been successful.…”

“…These product gases are subsequently transported in a combustion chamber and combusted at temperatures of around 1200°C. The exhaust gases generated during this process drive the Stirling engine and can be used for cogeneration purposes (Schneider et al., 2020; Zhu et al., 2021). Another approach is to utilize solar energy by coupling a solar dish with a Stirling engine.…”