Trying to use Nat Gas to fire the old coal boiler would be about half as efficient as putting in a combined cycle power turbine. A Power Turbine also generates electricity from the expansion of gases, not just heat.
Posted on 04/11/2015 9:59:23 AM PDT by thackney
It was once a lot more... as a % of the mix in some areas.
Only in the last few years has it been back up with Nuclear and now growing to meet coal.
We did not stop but we surely slowed down for a good while before this graph.
Just do a little more research, Thack. Oslimeball And his NEW regulations going into effect are shutting down many, many plants that have decades life left in them.
One I am familiar with just makes steam that is gone in seconds and the new regs are so restrictive and expensive that it is shutting down. All totaled, the mining jobs and plant jobs will total about 250 that willbe gone. Jobs American Indians currently hold and they will be relegated back tothe reservation unemployed.
Texas used to be entirely self sufficient with their grid but thanks to Obama and his greenies we had to shut dow several coal plants and 6 new coal plants were canceled. Now Texas buys electricity during high demand summers from Mexico.
We arefools for shutting down all these coal plants, period. Of course the. Newest plants will be more efficient but when we have all these plants already online and paid for with 200 years of fuel it is insane to just throw it away. Obama will get his way with very, very expensive utilities for Americans and we just sit by and let it happen.
Why can’t they just tear out the steam turbines and put in NG engines? Leave the dynamos there?
I have, of the six plants planned to close discussed in this article:
2 were built in the 1940s, 3 built in the 1950s, and one built in the 1960s. None are new.
Trying to use Nat Gas to fire the old coal boiler would be about half as efficient as putting in a combined cycle power turbine. A Power Turbine also generates electricity from the expansion of gases, not just heat.
I understand, but that’s not what I asked.
It seems they could leave the dynamos and building in place, and install some new gear, engines and cabling.
How can gas turbines offer more efficiency than NG piston engines? It seems they produce a lot of power in a small package, but use tons and tons of fuel.
Efficiencies of a combined cycle nat gas cycle are at 60%. Far more efficient.
Trying to use the old steam turbine results in more losses and far more down time in the conversion. It makes more economic sense to use the new system.
Are you not reading my posts or what?
The turbine is more efficient. It may use “tons” of fuel but it produces “lots” of power.
http://www.cospp.com/articles/print/volume-11/issue-3/features/gas-turbines-breaking.html
01/05/2010
Gas turbines were not always this efficient. The first simple cycle model, developed in 1939 had an 18% thermal efficiency. Its turbine inlet temperature was less than 540°C, with an exhaust temperature a little over 260°C. These days, we are talking about around 40% simple cycle efficiency, with turbine inlet temperatures of 1500°C and exhausts up to 630°C – and of course, on much larger machines.
CCGT, of course, represented a major leap northward. But they only gained real market traction in the early 1990s. By that time, developments in steam and gas turbine technology, as well as bleed over from the aviation field, had advanced enough to usher in the era of high efficiency turbines.
This was achieved by a combination of better alloys, coatings, combustors, compressor ratios, higher turbine inlet temperatures, better cooling, advanced heat transfer technology and a whole lot more. ‘Higher gas turbine efficiency is obtained not only through operation at higher turbine inlet temperatures and pressure ratios, but also with improved compressor and turbine aerodynamic designs, improved seals, better clearance control and larger engines,’ says Dale Grace, senior project manager in Electric Power Research Institute’s Generation Sector Combustion Turbine research.
The evolution of Siemens turbines serves as a case in point. By end of the 1980s, the E-class provided a 145 MW gas turbine coupled with a 80 MW steam turbine with approximately 50% net efficiency, such as at in Bang Pakong in Thailand.
‘The combined-cycle plant at Killingholme, UK, had achieved an efficiency of 52% in 1992,’ says Fischer. ‘In the last 15 years, the efficiency of combined-cycle power plants has been improved continuously.’ By the tail end of that decade, the F-class had risen to 56%. Incremental changes throughout the next ten years pushed the figure ever closer to the 60% goal (Figure 1).
‘Today, the most modern F-class is at 58.7% ISO at the high end. Nevertheless it can achieve beyond 59% as proven at Irsching 5 in Germany and Sloecentrale in the Netherlands for example,’ says Fischer. ‘This was attained by increasing firing temperature and optimization of the steam water cycle without hampering the flexibility through additional external cooling systems. In combination with increasing the compressor mass flow, the power output could be increased as well.’
http://instituteforenergyresearch.org/topics/policy/power-plant-closures/
This might help you some more.
I have already wasted too much time on this.
I’m talking about the plant closures discussed in the article of this thread.
I’m not.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.