HispanicBusiness

SEATTLE, WA -- (Marketwire) -- 10/11/12 -- ClearSign Combustion Corporation (NASDAQ: CLIR), an emerging leader in combustion and emissions control technology for industrial, commercial and utility markets, reported today that it has successfully demonstrated an experimental concept proof of a technique for cooling turbine blades that the Company believes may point the way to significant improvements in the design and performance of combustion turbines.

According to industry estimates, the combined annual market for both land-based natural gas turbines for power generation and jet engines for civil aviation is in excess of $40 billion annually. The Congressional Research Service stated that the use of gas turbines accounted for 19% of energy production in 1989, increasing to 39% in 2008, and projects this trend to continue for the next two decades. Turbomachinery Magazine's 2011 report projects that 11,480 land-based turbines will be delivered before 2019.

The market for aircraft jet engines is also projected to experience significant growth. General Electric, which accounts for approximately 50% of the global market, projects its current installed base of 26,000 engines to increase to over 45,000 by 2020.

Depending upon its size, a gas turbine running in single cycle mode can range from as little as 20% to as much as 45% efficiency. This is why small gains in energy efficiency are prized and sought after in the world of turbine engines.

Turbine efficiency is limited by the capacity of turbine blades and metal structures within the turbine to withstand high levels of sustained heat loading without suffering structural damage. In order to minimize mechanical stresses on the blades, turbines are designed so that hot combustion gases are cooled to well below their peak temperature before coming in contact with the rotor blades. Since the mechanical output of a turbine derives directly from the expansion of the gas as temperature is increased, cooling the hot inlet gases, while necessary to protect the blades, has the consequence of severely limiting turbine efficiency.

"If the blades can be cooled you're going to see a gain in efficiency," said ClearSign CEO Rick Rutkowski, "because you will be able to increase the peak temperature. The economic value of effective blade cooling is enormous since it translates directly into fuel savings for both jet engines and power generators. A gain of just one percent in efficiency is seen by industry experts as being very significant. We believe that it may be possible to realize gains of as much as a few percent in energy efficiency, if we can sufficiently cool the blade surfaces."

Currently, turbine designers employ "film-cooling" techniques to deliver cooling air to the blades in order to reduce heat buildup. However, shear forces from the high-speed rotation of the blades quickly pull this cooling air away.

The ClearSign blade-cooling concept involves electrically charging both the hot gas cloud and the turbine blades so that the hot gases are pushed away and cooling air is sandwiched between the charged blade and the gas cloud. The boundary layer of cool air effectively insulates the blade to reduce heat loading.