Enhancing power output and profitability through energy-efficiency techniques and advanced materials in today’s industrial gas turbines

Abstract

This paper reviews and integrates the latest energy-efficiency improvement techniques to recently developed superalloys and coatings for enhancing power output and profitability in today's industrial gas turbines (GTs). It has been shown that the retrofitting of inlet air cooling and steam injected gas technology technologies in simple turbines can boost power output from 30 to 48.25 MW and improve generation efficiency from 29.9% to 33.4%. It has been reviewed that for improving efficiency of power plants beyond 60%, it is important to use higher turbine inlet temperature (TIT) in combined cycle gas turbine by applying single-crystal nickel-based superalloys and thermal barrier coating involving closed-loop steam cooling. It has been shown that an increase of the TIT by 56°C can result in increased revenue of US$8/kW to the manufacturer of the original rating, provided the GT is sold for US$200/kW. In view of the latest development in GT technology, which enables them to be operated at TIT = 1,600°C, it is recommended to develop superalloys based on higher-melting temperatures (Mo-based superalloys). A new chart for increasing power output has been developed so as to enable the GT designers to manufacture GT engines with enhanced profitability.

Thermodynamics of CMC bladed marine gas turbine-LM 2500: Effect of cycle operating parameters

“…With the adoption of these techniques, gas turbine-based combined cycles have reported efficiencies of over 60%. 18,19 To further exploit the possibilities of enhancing the efficiency through increased TIT, researchers have put up the ideas of novel materials for blades. These materials include refractory metal alloys, metal matrix composites (MMCs), and ceramic matrix composites (CMCs).…”

Effect of artificial aging treatment on microstructure, mechanical properties and fracture behavior of 2017A alloy

“…For Al-Cu based alloy, the precipitation sequence is based on the formation of the first coherent phase called a GP (Guinier Preston) zone which is then followed by intermediate coherent (𝜃 ′′ ) and semicoherent (𝜃 ′ ) phases before the stable θ(Al2Cu) phase. The precipitation reaction during the aging process for an Al-Cu alloy, such as 2017A is quite complex or/and not well defined in the literature, but can be generally described as follows [7][8][9][10]:…”

“…Precipitation hardening treatment generates different microstructures; the mechanical properties of the based Al-Cu alloys are strongly dependent on the nature of the microstructure obtained after treatment i.e. the type, size, coherency, spacing and distribution of the precipitates in the microstructure impact strength evolution of the material [8,11].…”