Regenerative Gas Turbine Cycle Research Articles

Highly Efficient Gas Turbine System Using Isothermal Compression.

If the compression process of a regenerative gas turbine cycle is replaced by an isothermal compression process, higher thermal efficiency can be expected. This new cycle is a combination of parts of the Brayton and Ericsson cycles, and it is expected to achieve high efficiency. Isothermal compression in this cycle can be achieved by using a hydraulic air compressor, which converts hydraulic energy to energy of compressed air. The performance of such a system was analyzed by assuming conventional operating conditions and component characteristics. As a result the higher thermal efficiency of the system was proved. The application of this system to a conventional hydraulic power plant was discussed.

Low-leakage and High-Flow Regenerators for Gas Turbine Engines

The preliminary analysis and development of two new forms of regenerative heat exchanger that seem to promise greatly improved performance characteristics is described. To reduce drastically the usually high leakage and high seal wear rates suffered by present rotary regenerators, discontinuous rotation of the matrix has been studied, with seals that clamp the matrix during the stationary periods. To enable the regenerative gas turbine cycle to be used at high powers, regenerators consisting of movable ceramic modules are being investigated. The potential applications of the discontinuous-rotation type are particularly to small lightweight gas turbine engines such as those for automotive applications and to helicopters and light turboprop aircraft. The modular regenerator is being studied in application to burning coal and biomass of gas turbine engines and to larger marine and stationary base-power engines with power outputs of up to (and possibly beyond) 100 MW.

Graphical exergy analysis of complex cycles

Advanced thermal power systems (i.e. the gas-steam combined cycle, the steam injected gas turbine cycle and the regenerative gas turbine cycle) are complex systems with a basic gas turbine cycle. They have been analyzed by using a graphical exergy analysis that generates energy-utilization diagrams (EUDs). Comparison of the EUDs shows that the recently advanced systems have potential for substantial improvements. Suggestions for future improvements are described.

High-Efficiency Gas Turbine System Using Isothermal Compression. 1st Report, Performance Estimation.

If the compression process of a regenerative gas turbine cycle is replaced by an isothermal process, higher thermal efficiency can be expected. This combination of Brayton and Ericsson cycles has a potentially higher efficiency. Isothermal compression can be achieved using a hydraulic air compressor, which converts hydraulic energy into the energy of compressed air. It can be used as the compressor of the gas turbine system. The performance of the system was analyzed by assuming conventional operating conditions and component characteristics. As a result, the higher thermal efficiency of the system was proven, and an output larger than that of a conventional hydropower plant was obtained.

The application of gas-turbine technique to steam power

Early attempts to adapt the mechanism of the turbine to the air- or gas-engine were frustrated by the losses in the compressor, but in the last twenty years improvements in the efficiency of the latter, together with better high-temperature metals for the turbine, have enabled the gas turbine to approach the efficiency of the steam turbine. The gas turbine has to operate from a much higher temperature and with more effective high-temperature regeneration to achieve this. On the other hand it cannot utilize heat down to anything like the same lower temperature as steam power. Most regenerative gas-turbine cycles are therefore more efficient than the steam cycle at the upper temperature range, and less efficient at the lower temperature range. Now that the Rankine steam cycle has reached 1,000 deg. F., a given increment of temperature has much less effect on the steam turbine than on the gas turbine.The paper describes a condensing gas-turbine† cycle with external combustion, which utilizes orthodox gas-tur...

The Application of Gas-Turbine Technique to Steam Power

Early attempts to adapt the mechanism of the turbine to the air- or gas-engine were frustrated by the losses in the compressor, but in the last twenty years improvements in the efficiency of the latter, together with better high-temperature metals for the turbine, have enabled the gas turbine to approach the efficiency of the steam turbine. The gas turbine has to operate from a much higher temperature and with more effective high-temperature regeneration to achieve this. On the other hand it cannot utilize heat down to anything like the same lower temperature as steam power. Most regenerative gas-turbine cycles are therefore more efficient than the steam cycle at the upper temperature range, and less efficient at the lower temperature range. Now that the Rankine steam cycle has reached 1,000 deg. F., a given increment of temperature has much less effect on the steam turbine than on the gas turbine. The paper describes a condensing gas-turbine† cycle with external combustion, which utilizes orthodox gas-turbine and steam-turbine components in such a manner that the thermodynamic advantages of the two in the respective temperature ranges mentioned above are combined to give a higher thermal efficiency than either the steam or the gas turbine is capable of alone, and with the prospective ability to utilize almost any fuel. A great improvement may thus be made possible in the fuel economy of condensing steam power stations, steamship propulsion, and steam locomotives, and in the ratio of mechanical power to heat in combined power and process or district heat production. It may become commercially worth while, apart from the saving in coal, to eliminate a large proportion of condensing operation on land in the winter months. By integrating the fuel-using industries in this manner it should be possible to save at least fifty-million tons of coal per annum on the present aggregate output of power and heat, with a further saving of eleven-million tons of locomotive coal. This should enable the nation to afford much more liberal use of power and heat and thus achieve much greater production in transport and industry.