Part 2

Gas turbines have a rich history and play a key role in many of the modern-day technology we rely on. Welcome to part 1 of this blog where we’ll look at the history and evolution of gas turbines and don’t forget to join us for part 2 (next week) which will take a deeper look into hydrogen energy and where these machines are headed. 

The First Industrial Gas Turbines

Gas turbines are unique in many respects. First, they are among the most ancient turbomachines in their idea (approximately the 15th century) and at the same time, quite young in terms of practical implementation (the turn of the 19th–20th centuries).

Prototypes of gas turbines, which included the so-called smoke machines, began surfacing as early as the 17th century. However, the starting point in the development of gas turbines can be considered to have taken place in 1791 when Englishman John Barber filed an application for a heat engine patent.[1].  The turbine was equipped with a chain-driven reciprocating compressor and had a combustor and turbine. Barber proposed the use of charcoal, gas, or other suitable fuels to produce inflammable gas. The gas from the producer went into a common receiver and then into the combustion chamber where it mixed with compressor air and was ignited. The resulting hot gasses were allowed to impose on a turbine wheel.  To prevent overheating of the turbine parts, provisions to cool the gas by means of water injection were incorporated. There is no record of this engine being built but, in any event, it is unlikely that it would have self-sustained because of the large power requirements of the reciprocating compressor.  A patent drawing of Barber’s device is shown in Figure 1 [2].

In 1872, Franz Stolze designed an engine with an axial compressor, an axial turbine on the same shaft, a heat exchanger, a gas producer, and a combustion chamber. The gas turbine unit (Figure 2) was created and designed to produce 200 hp at a speed of 2000 rpm. However, the tests were not successful and instead only produced 20 hp. [1]

By 1900, Carnot, Gibbs, and Maxwell established the laws of thermodynamics. In 1906, the French engineers Armengaud and Lemale, with the participation of Auguste Rateau, built a gas turbine with a heat supply at a constant pressure with a power of 400 hp. (294 kW). The plant had a 2-stage centrifugal compressor. The turbine nozzle blades were water-cooled, and water from the cooling system was supplied to the kerosene combustion products, reducing their temperature to 560°C. The turbine developed a power slightly higher than the compressor power, so the compressor was driven by an external engine.

Also in 1906, the Russian engineer V.V. Karovodin invented, and in 1908 in France, built a gas turbine unit with intermittent combustion or combustion at a constant volume (Figure 3). The power expended on air compression in such installations is significantly lower than that of constant pressure gas turbine installations. The turbine developed a power of 1.6 hp. (1.18 kW) at 10,000 rpm, and the effective efficiency reached only 2%.

In 1908, German engineer Hans Holzwarth proposed the original design of an intermittent combustion gas turbine. In 1910, this installation was built by the Swiss company Brown Boveri. The combustion chamber, nozzles, and turbine wheel were cooled with water. The centrifugal compressor was driven by a steam turbine. This steam was obtained both by cooling the combustion chamber and by the heat of the turbine exhaust gases. The Holzwarth plant was one of the first combined-cycle plants in operation. In this version of the technology, the compressor is not as important as in a gas turbine continuous combustion plant, since combustion occurs at a constant volume (with closed valves at the inlet and outlet of the combustion chamber) and therefore the pressure in the chamber rises above the pressure developed by the compressor. That said, the gas turbine turned out to be more complex and expensive than a continuous combustion gas turbine since its operation required complex valve arrangements and a steam turbine with a condenser. On this installation, a power of 200 hp was achieved. (147 kW) at an efficiency of about 14%[1].

Several intermittent combustion gas turbines were built according to Holzwarth’s designs (one of them is shown in Fig. 3.14). Since in the first decades of the last century the implementation of such gas turbines was carried out more successfully than continuous combustion gas turbines, intermittent combustion gas turbines played a more significant role in the progress of gas turbine technology. In 1928, the Swiss company Brown Boveri resumed the construction of gas turbines designed by Holzwarth. Soon after, the company received an order for the development and in 1939 began to manufacture these types of turbines. The efficiency of these turbines operating on a two-stroke cycle was estimated at 18-20%, and the maximum power was 5000 hp. This can be considered the birth of the first industrial stationary gas turbine plant[1].

The First Aviation Gas Turbine Units

Gas turbine development for aircraft propulsion started in the early 1930s in Great Britain and Germany. In Britain, Frank Whittle of the Royal Air Force, organized a company to develop turbojet engines. His first engine, with a centrifugal compressor, ran in a test bed in 1937. In 1939, his first aircraft engine, the W-1, was produced. This turbojet delivered 388kg (855 lb) of thrust and weighed 283kg ( 623lb). (See Figure 4). [3]

The Gloster E28/39 aircraft (Figure 4) powered by the W-1 turbojet engine first flew on May 15, 1941. Late in 1936, a group in Germany, under the direction of Hans von Ohain at the Heinkel Aircraft Company began work on a centrifugal compressor engine. In 1937, work began on axial turbojet engines in Germany. The HE S3B engine, which delivered 500 kg (1100 lb) of thrust, propelled the first turbojet flight on August 27, 1939. Junkers then developed the JUMO 004, an axial compressor engine that was used in the ME 262 aircraft during the war. In the United States, the Westinghouse Electric Corporation and the General Electric Company pioneered in the field of axial-flow turbojets. Before and during World War II, both the former Soviet Union and Japan also participated in the development of gas turbines for aircraft propulsion.

The Evolution of Gas Turbine Efficiency 

If we compare the schemes of early gas turbine prototypes (which did not show positive results), with modern gas turbine plants, we can see that there are no fundamental differences between them. The main reasons for the failures in the creation of a workable and efficient gas turbine engine were associated with the aerodynamic imperfection of compressors and turbines, as well as the absence at that time of heat-resistant steels capable of operating for a long time at high temperatures. The lack of experience in creating cooling systems for the main parts and assemblies of gas turbine plants also played a role[1].

The foundation for the development of the theory of turbomachines, of which the theory of gas turbines is an integral part, was laid back in the 17th–19th centuries. The cornerstone of the theory is the thermodynamics of working processes in gas turbine plants. It is based on the basic postulates and laws of thermodynamics proposed by Carnot, Mayer, Helmholtz, Clausius, Boltzmann, Boyle, Gay-Lussac, Clapeyron, Thomson, and others. The works of Euler, Bernoulli, and others formed the basis of gas-dynamic and hydraulic calculations of turbomachines.

The thirties and forties of the twentieth century are characterized by major achievements in the field of aerodynamics of turbines and compressors. For turbines, the task of creating highly efficient blade profiles and the flow path was solved much easier than for compressors, which is associated with differences in the nature of the flow in the turbine and compressor stages. If by the beginning of the 1940s the internal efficiency of turbines reached 86–88%, largely due to the experience of creating steam turbines, then the aerodynamic efficiency of compressors was at a level of 74–75%, which made it impossible to create an efficient gas turbine plant with an efficiency above 15–18%.

The improvements in the gas turbine cycle have historically been aimed at increasing efficiency, lowering investment costs, and reducing environmental emissions. To increase efficiencies, turbine designers have worked to increase firing temperatures without damaging the turbines. However, firing turbines beyond the threshold temperatures of their components threaten their integrity and reliability. The development of advanced cooling techniques and improving materials are two major strategies for solving this problem. The improvements in the individual efficiencies of the main gas turbine components like the compressor and turbine have also helped in increasing the gas turbine efficiency. In addition, improved efficiency can be achieved by modifications to the original simple cycle to recover heat from the turbine exhaust [11].

The simple cycle gas turbine power plants designed to be suitable for electric utility applications have the advantage of high power output for a relatively small size and weight, low initial cost, rapid installation, short start-up times, fuel flexibility, and zero water consumption for cooling. A typical gas turbine for electric utility applications has a power output range between 50 kW and 240 MW [11].

In the past, one of the major disadvantages of the gas turbine was its low efficiency compared to other internal combustion engines and steam turbine power plants. However, continuous engineering development work has pushed the electric efficiency from 18% for the first gas turbine in commercial operation, the 1939 Neuchatel gas turbine, to present maximum levels of about 40% for simple cycle operation. Improvements to the simple cycle and additions of steam turbine bottoming cycles offer the capability of further increases in efficiency. Today, a combined gas turbine, and steam turbine cycle is capable of achieving an efficiency of almost 60% [11].  Figure 6 shows a timeline of the development of power generation technology.

An increase in the initial temperature of the turbine cycle makes it possible to increase the efficiency of the gas turbine plant, but this, in turn, leads to an increase in harmful emissions into the atmosphere. The environmental aspect remains important when using gas turbines, so today many of the world’s leading manufacturers are trying to take it into account when designing and operating gas turbines.

Join us for part 2 next week where we’ll dive into the modern-day gas turbine development trends, including hydrogen energy.

Interested in learning about how AxSTREAM can help you with your gas turbine development? Contact us to request a trial!

Part 2

Blog references:

1. http://energetika.in.ua/ru/books/book-3/part-1/section-3/3-6
2. The Historical Evolution Of Turbomachinery. – C. Meher-Homji. – Published 2000 – Engineering DOI:10.21423/R1X948Corpus ID: 116230226
3. The History of the Siemens Gas Turbine Ihor Diakunchak, Hans Juergen Kiesow, Gerald McQuiggan T2008-50507, pp. 923-935; 13 pages
4. https://en.wikipedia.org/wiki/Power_Jets_W.1
5. Review on the Development Trend of Hydrogen Gas Turbine Combustion Technology.-Daesik Kim, Kim Dae-sik.-Journal of The Korean Society Combustion. December 2019. 1-10
6. York, M. Hughes, J. Berry, T. Russell, Advanced IGCC/hydrogen gas turbine development, Final Technical Report, DE-FC26-05NT42643 (2015) submitted to US Department of Energy.
7. Larfeldt, M. Andersson, A. Larsson, D. Moell, Hydrogen co-firing in Siemens low NOx industrial gas turbines, Power-Gen Europe, Germany, 2017.
8. Tekin, M. Ashikaga, A. Horikawa, H. Funke, Enhancement of fuel flexibility of industrial gas turbines by development of innovative hydrogen combustion systems, Gas Energy, 2 (2018) 1-6.
9. Hydrogen Power Generation Handbook, Mitsubishi Hitachi Power Systems, Ltd., Japan, 2018, 1-45.
10. Rizkalla, R. Keshavabhattu, F. Hernandez, P. Stuttaford, FlameSheet combustor extended engine validation for operational flexibility and low emissions, ASME Turbo Expo, GT2018-75764, 2018
11. Analysis of Gas Turbine Systems for Sustainable Energy Conversion. – Marie Anheden, – Royal Institute of Technology Stockholm, Sweden 2000 TRITA-KET R112 ISSN 1104-3466 ISRN KTH/KET/R–112–SE