hifiandmtb
Sphincter beanie
His CO2 figures are also wrong.
Plastic bags, climate change, renewable energy,
- Thread starter John U
- Start date
Haakon
has an accommodating arse
I wouldn’t even bother engaging him. Met his sort many times. It’s good to be proud of your job, and process engineers are super valuable people to have and worthy careers.
But it doesn’t equal actual climate science nor does it make you a policy expert.
But of course these days everyone is an expert on everything...
Haakon
has an accommodating arse
Wow, he must be super rich on the back of those patents!!!
Mostly shit. Boilers are not 90 something percent efficient. The rest is as bad. Munmorah was so good it was pulled down years ago. Not worth arguing the points which are so wrong.
Best practice with ultrasupercritical units is still a little over 40% overall. Combined cycle gas turnines can squeeze towards 60%. You can stretch that if you make use of the low quality steam that is otherwise condensed.
My source - me. I did this for 30 years including design, construction, commissioning, operation and maintenance.
Best practice with ultrasupercritical units is still a little over 40% overall. Combined cycle gas turnines can squeeze towards 60%. You can stretch that if you make use of the low quality steam that is otherwise condensed.
My source - me. I did this for 30 years including design, construction, commissioning, operation and maintenance.
hifiandmtb
Sphincter beanie
Flow-Rider
Burner
Somebody has taken information out from the original post, he claims that lot of the efficiency is lost at the turbine. I'm not sure what he is claiming as a modern boiler but the gas boilers are certainly up there.
cokeonspecialtwodollars
Fartes of Portingale
106% efficient?
Flow-Rider
Burner
Don't ask me I'm not an engineer or selling the product but the original article I quoted is wrong someone left out info on it. He still stands by his boiler figures though, maybe someone needs to ask what boiler is he talking about.
cokeonspecialtwodollars
Fartes of Portingale
As Terence has clarified the overall efficiency around 40% is more in line with what we would expect to see and all we really care about.
We are talking about power boilers not condensing water heaters which makes the energy in vs heat out calculation dodgy. 106% efficiency is like the cop of an airconditioner.
I don't have exact numbers so this is from memory and out of my arse.
A subcritical coal fired power boiler at rated output will be around 80% efficient, that is energy in the steam out of the boiler compared to energy input burning coal. Losses are radiation from the boiler's walls etc and heat not extracted in the flue gases. Modern insulation is good but you will still heat the overall boiler exterior to 50-60C. Work out the area and you can calculate the losses. Also the flue gas exits the air heater at roughly 130C. This is the golden rule for design. From there no more energy is extracted from the gas. This is mainly to stop or reduce back end corrosion in the airheater and the bag house or electrostatic precipitators and stack. Work out how much energy was lost heating the air from 20C to 130C... the coal will be 15-30% ash so we need to heat that up for nothing and anything from 5-30% moisture, again a parasitic load on our fire. We also lose some carbon not burned, worse for a fluidised bed boiler but still wasted energy.
A 350MW unit, something like Munmorrah would burn around 160 - 180 tonnes of coal an hour to produce 350MW. Ish, but this is pretty close. Coal used in Oz runs to something like 24-28MJ/kg calorific value so burning that we are using 160 * 1000 * 26 / 3600 MW or say 1200MW. To produce 350MW of electricity. So 34% ish overall.
Heat is lost in the steam running to and from and back again to the steam turbine. Energy is lost due to flow losses. The turbine too sits there radiating heat that isn't converted into electricity. There are shaft losses (friction) in the turbine and generator and also losses in expanding the steam over the turbine blades and diaphragms. Then there are the losses condensing the steam at the turbine exit into water so it can be pumped back around the circuit to do it all again. Massive energy is lost through the condenser creating those lovely steam plumes from the cooling towers. And when you think that is it don't forget about 10% of electricty generated goes to running the pumps, fans, actuators, conveyors, crushers, water treatment etc etc needed to make it all run.
Then we have electrical losses. The generator (alternator really) is pretty good. High 90s with some losses for cooling (most commonly cooled with hydrogen gas!). Transmission losses stepping the generator output up to 275kV for transmission and then good old transmission losses which can be small and can be crazy big depending on the network and demand.
I havent mentioned CO, CO2, SOX, NOX and the iron carried out with the flue gas from erosion caused by the aggressive nature of the ash created in combustion.
I probably missed stuff but you get the idea.
This improves for supercritcal because you can ram more energy into the steam through better materials and again higher still for ultrasupercritical. Subcritical HP and IP stage steam turbines accept steam at something like 540C, higher than that and the blades start to get friendly with the casing over time. cat 3,000 rpm this gets a bit noisy. Go supercritical and the temperature climbs to 570-600C. Ultrasupercritical and that can get to 660C. I worked a bit on an 1100MW USC boiler that was doing these (660C) sort of numbers. Not here obviously. Materials start to get a bit fancy and more exotic so cost increases rapidly.
In Australia we have four supercritical stations. The first was Callide C with two units rated at 405MW a piece. These use about the same quantity of coal as the 350MW subcritical boilers next door but they are more expensive to maintain. Millmerran runs two 420MW units, Tarong North has a 450MW unit and Kogan Ck is 750MW and is the biggest single unit in Australia.
The biggest blight in power generation are the brown coal units which are filthy because they are trying to burn sloppy wet real estate instead of coal.
I don't have exact numbers so this is from memory and out of my arse.
A subcritical coal fired power boiler at rated output will be around 80% efficient, that is energy in the steam out of the boiler compared to energy input burning coal. Losses are radiation from the boiler's walls etc and heat not extracted in the flue gases. Modern insulation is good but you will still heat the overall boiler exterior to 50-60C. Work out the area and you can calculate the losses. Also the flue gas exits the air heater at roughly 130C. This is the golden rule for design. From there no more energy is extracted from the gas. This is mainly to stop or reduce back end corrosion in the airheater and the bag house or electrostatic precipitators and stack. Work out how much energy was lost heating the air from 20C to 130C... the coal will be 15-30% ash so we need to heat that up for nothing and anything from 5-30% moisture, again a parasitic load on our fire. We also lose some carbon not burned, worse for a fluidised bed boiler but still wasted energy.
A 350MW unit, something like Munmorrah would burn around 160 - 180 tonnes of coal an hour to produce 350MW. Ish, but this is pretty close. Coal used in Oz runs to something like 24-28MJ/kg calorific value so burning that we are using 160 * 1000 * 26 / 3600 MW or say 1200MW. To produce 350MW of electricity. So 34% ish overall.
Heat is lost in the steam running to and from and back again to the steam turbine. Energy is lost due to flow losses. The turbine too sits there radiating heat that isn't converted into electricity. There are shaft losses (friction) in the turbine and generator and also losses in expanding the steam over the turbine blades and diaphragms. Then there are the losses condensing the steam at the turbine exit into water so it can be pumped back around the circuit to do it all again. Massive energy is lost through the condenser creating those lovely steam plumes from the cooling towers. And when you think that is it don't forget about 10% of electricty generated goes to running the pumps, fans, actuators, conveyors, crushers, water treatment etc etc needed to make it all run.
Then we have electrical losses. The generator (alternator really) is pretty good. High 90s with some losses for cooling (most commonly cooled with hydrogen gas!). Transmission losses stepping the generator output up to 275kV for transmission and then good old transmission losses which can be small and can be crazy big depending on the network and demand.
I havent mentioned CO, CO2, SOX, NOX and the iron carried out with the flue gas from erosion caused by the aggressive nature of the ash created in combustion.
I probably missed stuff but you get the idea.
This improves for supercritcal because you can ram more energy into the steam through better materials and again higher still for ultrasupercritical. Subcritical HP and IP stage steam turbines accept steam at something like 540C, higher than that and the blades start to get friendly with the casing over time. cat 3,000 rpm this gets a bit noisy. Go supercritical and the temperature climbs to 570-600C. Ultrasupercritical and that can get to 660C. I worked a bit on an 1100MW USC boiler that was doing these (660C) sort of numbers. Not here obviously. Materials start to get a bit fancy and more exotic so cost increases rapidly.
In Australia we have four supercritical stations. The first was Callide C with two units rated at 405MW a piece. These use about the same quantity of coal as the 350MW subcritical boilers next door but they are more expensive to maintain. Millmerran runs two 420MW units, Tarong North has a 450MW unit and Kogan Ck is 750MW and is the biggest single unit in Australia.
The biggest blight in power generation are the brown coal units which are filthy because they are trying to burn sloppy wet real estate instead of coal.
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Haakon
has an accommodating arse
Nice one Dale.
I’ve been through Loy Yang A a couple of times on tours for work (got to look inside a running furnace, super cool!) and was always incredibly impressed with them. That they can get glorified mud to burn at all is amazing!
Another proposed load worth considering is the mythical Carbon Capture and Storage caper so many seem to think is a thing - to operate a post combustion capture you’re looking at at least 30% of the generated power to operated it. When you’ve already got coal power shedding load because they’re being undercut by cheaper solar and wind you can’t see CCS ever having the multibillions invested... (assuming it would even work anyway).
I’ve been through Loy Yang A a couple of times on tours for work (got to look inside a running furnace, super cool!) and was always incredibly impressed with them. That they can get glorified mud to burn at all is amazing!
Another proposed load worth considering is the mythical Carbon Capture and Storage caper so many seem to think is a thing - to operate a post combustion capture you’re looking at at least 30% of the generated power to operated it. When you’ve already got coal power shedding load because they’re being undercut by cheaper solar and wind you can’t see CCS ever having the multibillions invested... (assuming it would even work anyway).
hifiandmtb
Sphincter beanie
Haakon
has an accommodating arse
It really doesn't. Just ask Chevron...
Flow-Rider
Burner
Brown paper bags full on money are too big, well at least in Qld. andrew-antoniolli-fraud-charge-corruption-watchdog They already jailed the prick before him Pisasale and it's in the area where good old Pauline is popular too.
Binaural
Eats Squid
Wow, some serious bullshit there, from the very first sentence - course 60-90% of the energy does go up the chimney. This guy is pretending that people are talking about boiler efficiency, when it is abundantly obvious to any casual observer that power plant efficiency refers to the overall thermal efficiency from coal combustion, not one stinking heat transfer element. I particularly enjoyed his offhand statement that 3MW is the largest wind turbine you can get - GE are currently building one 4 times as large. Pretty much any given detail doesn't check out, or is expressed in a technically inaccurate way because he doesn't understand what it is telling him (and the limitations).
The rest of this gibberish illustrates beautifully that genuine technical expertise is hard to get, and it turns out that being a commissioning or maintenance engineer doesn't make you an expert in power station design engineer by a looooong shot, or even a halfway intelligent commentator on comparing energy technologies. This is the exact situation described by the Dunning-Krueger curve, where a bit of knowledge in one aspect of a complex problem encourages the unwary to think they know far more than they really do.
I am sorry, but your friend is a prime example of what's wrong with the climate debate - no regard for fact checking, garbage maths, speaks with great confidence about things he knows nothing about.
hifiandmtb
Sphincter beanie
https://www.themonthly.com.au/issue...0/jo-lle-gergis/terrible-truth-climate-change
If it emits carbon from being dug up & burnt, it's bad. The end.
Haakon
has an accommodating arse
hifiandmtb
Sphincter beanie
Old mate summarised it nicely this morning:
- For a 50% chance of 1.5C with low overshoot, the emissions pathway states we need to decarbonise globally at 4.5%/yr, and we need massive CDR.
- We’re currently CARBONISING at 2.8%/yr.
- The collapse of the Soviet Union was -9%/yr for a few years (one country) and resulted in massacres, riots and hardship.
- 50% chance of failure is ridiculously high.
- Even a pathway decarbonising at -1.6%/yr leaves a 40% chance of >2C. The last time Earth was that warm was 3-5 million years ago during the mid-pliocene, CO2 was 400ppm and seas were 10-20m higher.
- So much additional CDR is needed along with decarbonisation, that it equates to an annual amount by 2030 equivalent to that sunk by a quarter of the global ocean, a full ocean annually by 2050, and 17 oceans worth in total sunk/sequestered before 2050.
- We currently deforesting the planet reducing the existing natural carbon sink.
Scotty T
Walks the walk
@Dales Cannon thanks for throwing down real expert knowledge. What are your thoughts on solar thermal for super critical steam? Asking because CSIRO has done some work on it but it's not gaining traction as far as I can see.