Can Gas Turbines Be Revisited and Improved Like Diesel Engines?

Gas turbine technology, much like diesel engines, has seen considerable advancements and improvements over the years. While diesel engines have benefitted from computerized control, enhanced fuel injection techniques, and other innovations, gas turbines are also undergoing significant changes. This article will explore how gas turbines can be revisited and improved, drawing parallels with the advancements in diesel engines.

The Evolution of Gas Turbine Technology

Gas turbine technology has been constantly evolving, with near-identical machines being up-rated regularly due to advancements in materials, blade cooling techniques, and aerodynamic improvements. The ability to achieve higher temperatures (Tslots) and thus greater efficiencies is a testament to this progress. For example, the 11,000 hp Solar Mars 90, introduced in 1980, was later upgraded to the Mars 100, with its current iteration increasing its power output from 15,000 to 16,000 hp. This showcases the incremental yet substantial improvements in gas turbine technology.

Modern Control Systems and Fuel Efficiency

Just like diesel engines, computerized control systems have significantly improved the performance and efficiency of gas turbines. With better metallurgical innovations and robust designs, gas turbines of newer frames (e.g., Frame IV to IX) have seen a sea change in several important domains. For instance, control systems have evolved from single processor systems to triple processor systems with redundancy. This has led to improved combustion control, better fuel efficiency, and enhanced safety measures.

Advanced Materials and Innovative Cooling Techniques

The present state of advancement in gas turbine technology includes the use of new generation high-temperature ceramic turbine blades and combustion chamber liners. These materials are designed to improve efficiency by withstanding higher temperatures and reducing heat transfer. Additionally, advanced cooling techniques, such as improved turbine blade coatings and enhanced cooling zones, further contribute to the efficiency and longevity of these machines.

Leading Innovations by GE

General Electric (GE) has made significant strides in gas turbine technology. For instance, the Frame-II machine had lower power output, control system limitations, and operator unfriendliness compared to newer models. GE's advancements have led to Frame IV to IX machines, which have seen considerable improvements in power output, control systems, and overall operator friendliness. Some key improvements include:

Triple Processor Systems: This design ensures redundancy and reliability in critical systems. Combustion Coatings: These are thermally barrier coatings (TBC) that allow for higher combustion temperatures. Enhanced Cooling Techniques: More cooling zones and higher flow rates improve turbine performance.

Parallel Advances in Diesel Engines

Similar to gas turbines, diesel engines have also seen significant advancements, particularly with the introduction of modern control systems and direct injection technologies. These innovations have greatly improved combustion control, equipment safety, and overall performance.

Current State and Future Prospects

The development of gas turbines has never gone dormant. Companies like GE have pushed the boundaries with technologies such as Class H gas turbines, which operate at temperatures above the melting point of turbine blades. The blades are protected by a thin blanket of steam during operation, providing an additional layer of protection. This cutting-edge technology highlights the continuous pursuit of higher performance and efficiency.

Application in Automotive and Aviation

While gas turbines can be efficient in specific applications, they are not well-suited for automobiles. The constant requirement of fuel to even keep the turbine "on" at idle consumes a significant amount of fuel. Gas turbines are more efficient at peak output, which is why we are seeing an increase in hybrid electric airplanes using gas turbines for peak performance applications. The challenge of balancing the weight and reliability of piston engines in these applications has led to the development of hybrid solutions.

Overall, while both gas turbines and diesel engines have seen remarkable advancements, the ongoing development in gas turbine technology shows that there is still significant potential for improvement and innovation. The right combination of materials, technologies, and design principles will continue to push the boundaries of performance and efficiency in this domain.