The Foam Turbine

The Foam Turbine is a power generator based on microturbine technology – RheOmega’s proprietary Foam Compression enhances efficiency and reduces equipment size & cost by significantly reducing the air throughput.

Background

Typical microturbines use a recuperated Brayton cycle to generate power and heat.

Recuperated Brayton Cycle

Ambient air is drawn into the Compressor – it is compressed adiabatically
The compressed air is preheated by the exiting exhaust via a heat exchanger called the Recuperator
In the Heater, fuel (e.g. natural gas, or others) is combusted in the preheated, high pressure air
The gas is expanded to produce work in the Turbine
The expanded gas passes through the Recuperator to preheat the post-compressor air, and is then exhausted

ORBrayton — The open regenerative (aka recuperated) Brayton cycle

In the Brayton cycle, the (adiabatic) compressor consumes 40% to 50% of the turbine’s work output!

Innovation

The Foam Turbine Cycle

Ambient air is drawn into the Foam Compressor – it is compressed near-isothermally
The compressed air is preheated by the exiting exhaust via a heat exchanger called the Recuperator
In the Heater, fuel (e.g. natural gas, or others) is combusted in the preheated, high pressure air
The gas is expanded to produce work in the Turbine
The expanded gas passes through the Recuperator to preheat the post-compressor air, and is then exhausted

FoamBCycleSch — The Foam Turbine cycle is based on the recuperated Brayton cycle – but the cycle derives its advantages from its near-isothermal Foam Compressor

When the compression is done near-isothermally, as in the Foam Compression process, the compressor’s energy consumption drops 20% to 30% – improving cycle efficiency by 4% and specific net work output by 40% to 50%. Improved specific net work reduces the gas flow rate by 30% to 40%

FoamBCycleEff — The Foam Compressor’s peak efficiency is 4% greater than the peak efficiency of the recuperated Brayton cycle

FoamBCycleMassFlow — At peak Foam Compressor efficiency (@ Pressure Ratio ~15), the mass throughput is reduced by nearly 40%

What is foam?

Foam is a stabilized mixture of gas and a carrier liquid – the mixture absorbs the heat of compression as it’s created, keeping the overall temperature moderate and thereby reducing the total amount of work needed for compression.

Foam has been demonstrated to be a practical, cost-effective, commercial-scale technology in Isothermal Compressed Air Energy Storage. RheOmega has the know-how to develop Foam Technology for advanced power cycles.