Hot, compressed air injection addresses gas turbine challenges

Powerphase, a developer of upgrades for gas turbines, has been issued a new US patent for a technology that improves the output, fuel efficiency and responsiveness of gas turbines, including those used in electric power generation, gas processing plants and industrial processes.

The gas turbine technology, dubbed "Turbophase," addresses a fundamental problem faced by all gas turbines: that gas turbines lose output at high ambient temperatures or elevations. Turbophase uses a fuel driven engine and its waste heat, along with a compressor in a cogeneration process to generate hot, compressed air approximately 35% more efficiently than the gas turbine itself. The air is then injected into the gas turbine, allowing it to produce its optimum output in all ambient conditions.

"Three major benefits are realized by using the waste heat from the fueled engine driving the compression process," says Bob Kraft, the inventor of Turbophase.  "First, the connection to the plant is very simple and takes about a day, second, because the power source is fuel, the auxiliary load is very low, approximately 0.5% of the incremental power generated; and lastly, and most importantly, because Turbophase is a co-generation process, the system can be efficiently added to a combined cycle power plant.

The Turbophase system has all the characteristics of a fast-responding, reciprocating engine power plant, except the power is generated at combined cycle efficiencies and the installed cost is less than half."

The company has installed Turbophase on the 6B and the 7FA, both manufactured by General Electric (GE). In addition, the company plans to introduce the same Turbophase technology on every land-based frame and aero-derivative gas turbine. Because all gas turbines use copious amounts of air in their combustion processes, greater air efficiency leads to greater fuel efficiency.

The most common methods for increasing output from gas turbines till now are inlet conditioning, injection of water or steam, and upgrades offered by OEMs. The company is working towards partnerships with all of the OEMs, and plans to offer its Turbophase technology-- and future technologies-- both in partnership with OEMs and directly to gas turbine owners globally.