Approach to improve thermal efficiency | Design features required in GT system | Additional benefit | Reference in text/figure/table | Citation |
---|---|---|---|---|
Intercooling | Pass the working fluid through a 1st stage compressor, then a cooler, followed by a 2nd stage compressor | An increase in the maximum feasible pressure ratio | ‘Intercooling’ section | Carapellucci 2009 |
Regeneration | Pass the still-warm post-turbine fluid through a heat exchanger to pre-heat the fluid just entering the combustion chamber | Offsets fuel consumption | ‘Regeneration’ section | Bassily 2008 |
Less power loss as waste heat | ||||
Combined cycle (CC) | Combine Brayton engine with Rankine engine to obtain gas-steam CC | Thermal efficiency as high as 60% | ‘Combined cycle’ section | |
Cogeneration | Couple natural gas turbine with electrical generator | Steam obtained may be used for hot-water production or space heating | ‘Cogeneration’ section, Figure 1 | Najjar et al. 2004; Brooks 2000; Agarwal et al. 2011; Pilavachi 2000 |
Direct exhaust heat from the GT to WHRB | ||||
Direct steam from WHRB to a steam turbine generator | ||||
IAC and STIG cycles | Cool the air before compression | Higher power output in peak summer demands | ||
Use the new economic system: ejector refrigeration system to cool turbine inlet air | Low power consumption by using ejector refrigeration system | |||
Add steam to the combustion chamber | ||||
Higher TIT | Use advanced/SC superalloy in turbine components | Higher revenue/profitability | ‘Higher turbine inlet temperature,’ ‘Enhancing profitability in power generation,’ and ‘Improving GT efficiency through advanced superalloys’ sections; Figures 5,6,7,8,9,10,11,12; Equations 3 and 4 | Nye Thermodynamics Corporation (NTC) 2011; Zeren 1982; Schulz et al. 2008; Braue et al. 2007; Huda et al. 2011; Jianting 2011; Cao and Loria 2005; Sajjadi and Nategh 2001; Sajjadi et al. 2002; Sajjadi et al. 2006; Zickler et al. 2009; Perepezko 2009; Todd 1989; Kansai Electric Power Company (KEPCO) 2011; Diologent and Caron 2004; Sajjadi and Zebarjad 2006; Kennedy 2005; Kitazawa et al. 2010; Pint et al. 1998; Wright and Gibbons 2007; Choi et al. 2010; Walston 2004; Troczynski et al. 1996; DeMasi-Marcinand and Gupta 1994; Movchan 1996; Schulz et al. 1997; Padture et al. 2002; Boccaccini and Zhitomirsky 2002; Boccaccini et al. 2006; Besra and Liu 2007; Corni et al. 2008; Dusoulier et al. 2011; Doungdaw et al. 2005; Mohanty et al. 2008; Put et al. 2003 |
Use TBC using EPD/EBPVD | MHI, J-series engine operating at TIT = 1,600°C has achieved efficiency exceeding 60% |