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If a turbocharger is configured to act as a heat recovery turbine it is significantly more complicated including again a generator. Therefore it can not be simp

If a turbocharger is configured to act as a heat recovery turbine it is significantly more complicated including again a generator. Therefore it can not be simpler than an electric motor, this should be obvious. This is referred to as turbo compounding not turbo charging [1]. Turbochargers allow more efficiency through engine downsizing and that they can be bypassed under light/cruising loads. That is you can have smaller engine that acts like a bigger engine under heavy loads but has the efficiency of a smaller engine at normal loads [2]. The turbo charger on the Frieghtliner is not part of the heat recovery system, it is compressing intake air in order to allow an increase of power by also injecting more fuel. If you attach a generator to the turbo to make it recover heat as output power it will no longer be able to use that work to compress intake air. Then it becomes a turbo-compounded engine. They use a steam turbine as it recovers more heat while adding almost no back pressure to the system. As shown to get a modest increase in thermal efficiency something much larger and more complicated must be used on a semi in addition to the turbocharger. Show me a fuel cell using a turbo charger to attain any significant heat recovery. Show me one that doesn't use a generator and is therefore simpler than an electric motor. You will not attain 60%+ thermal efficiency with a just a turbo charger and you know it. Fuel cells look to need a secondary combustion system in order drive the turbine properly due to them having no compression of their own so now you have a full gas turbine with generator on top of the fuel cell. 1. https://en.wikipedia.org/wiki/Turbo-compound_engine https://en.wikipedia.org/wiki/Turbo-compound_engine 2. http://large.stanford.edu/courses/2010/ph240/veltman1/ http://large.stanford.edu/courses/2010/ph240/veltman1/

darksaints 5y ago
I don't know where you keep getting this idea that I think a heat recovery turbine is simpler than a generator. All I said was that if you think a heat recovery turbine is too complex to be feasible, then you'll also think an electric motor is too complex to be feasible. Because neither are too complex to be feasible. And no, it is not complex at all. The turbine part stays the same as your garden variety turbocharger. Instead of directly attaching a compressor (which makes it a turbocharger), you directly attach a generator (which makes it a turbine-driven generator). In fact, you could even do both: power an intake air compressor as well as a generator. Literally anybody could build one in their back yard using parts ripped out of random cars at a junkyard. Without capturing any waste heat at all, Solid Oxide Fuel Cells are ~60% efficient. With a waste heat recovery turbine, you increase the efficiency. 75% efficiency is already feasible. https://www.sciencedirect.com/science/article/abs/pii/S0306261918310316?via%3Dihub https://www.sciencedirect.com/science/article/abs/pii/S03062... Yes, this solution is more complex than a normal fuel cell...in exactly the same way that a turbocharged engine is more complex than a naturally aspirated engine. That is to say not only is it entirely feasible, but it is a well developed easily adaptible solution that has been used for increasing efficiency for over a century now. Learn how to google...there are literally hundreds of papers detailing efficiency gains from using turbochargers on fuel cells. Hell, most turbocharger manufacturers are already making custom hybrid turbocharger/generator packages specifically designed for fuel cell use. https://www.garrettmotion.com/electric-hybrid/twostage-electric-compressor-for-fuel-cells/ https://www.garrettmotion.com/electric-hybrid/twostage-elect... https://www.mtu-solutions.com/eu/en/stories/technology/turbochargers-for-higher-engine-efficiency.html https://www.mtu-solutions.com/eu/en/stories/technology/turbo... https://cdn.borgwarner.com/docs/default-source/default-document-library/2014_whitepaper_charging-system-for-fuel-cell-applications_en.pdf?sfvrsn=b60acd3c_11 https://cdn.borgwarner.com/docs/default-source/default-docum... You thought it was infeasible because you were imagining a big ass steam engine, and when it was pointed out that turbochargers are an entirely commonplace form of heat recovery turbine, you backpeddled and tried to redefine words (b-b-b-but that's a Turbo Compounder!!!) to weasel your way out of it. Give it up. You're embarrassing yourself.
- SigmundA 5y ago
  >If a modern heat recovery turbine is too complex, then so is an electric motor. A generator is bascially an electric motor running in reverse, at minimum you have a turbine and a generator to make a heat recovery turbine, or you can mechanically couple it with a transmission. That is more complex than just an electric motor, is this not obvious to you? The SOFC you linked at 75% efficiency uses a turbine with a secondary combustion chamber (post combustor) and along with a generator. Again this is not just a "simple" turbocharger. https://d3i71xaburhd42.cloudfront.net/3362b2a27c2ec1f3064114a66c9791721af69fe4/5-Figure1-1.png https://d3i71xaburhd42.cloudfront.net/3362b2a27c2ec1f3064114... Does that look like just a simple turbo charger? You are the one redefining what a heat recovery turbine is, no one calls a turbo charger a heat recovery turbine, and no devices called heat recovery turbines are just a turbo charger at minimum they drive a generator or are mechanically coupled to an engines output. So you have on one hand a: battery - motor controller - electric motor VS high pressure liquid H2 tanks - fuel cell - recovery turbine with generator - motor controller - electric motor Hopefully the fuel cell can have enough burst power for acceleration and not also need a buffer battery like current fuel cell EV's, then again you need a battery or regenerative braking, oh well. Which one is simpler and cheaper to fuel, maintain and operate? Which has more moving parts? Current fuel cells in cars don't even have an energy density advantage, maybe they will and will outpace batteries but they are certainly not simpler than a battery powered EV. Also stop being an ass, you are the one embarrassing yourself, at least try and keep it civil.
  - darksaints 5y ago
    > Does that look like just a simple turbo charger? It doesn't look like a turbocharger, it looks like a system diagram of a fuel cell attached to a turbocharger. ::facepalm:: > You are the one redefining what a heat recovery turbine is, no one calls a turbo charger a heat recovery turbine, and no devices called heat recovery turbines are just a turbo charger at minimum they drive a generator or are mechanically coupled to an engines output. ::doublefacepalm::
    - SigmundA 5y ago

darksaints 5y ago

I don't know where you keep getting this idea that I think a heat recovery turbine is simpler than a generator. All I said was that if you think a heat recovery turbine is too complex to be feasible, then you'll also think an electric motor is too complex to be feasible. Because neither are too complex to be feasible. And no, it is not complex at all. The turbine part stays the same as your garden variety turbocharger. Instead of directly attaching a compressor (which makes it a turbocharger), you directly attach a generator (which makes it a turbine-driven generator). In fact, you could even do both: power an intake air compressor as well as a generator. Literally anybody could build one in their back yard using parts ripped out of random cars at a junkyard. Without capturing any waste heat at all, Solid Oxide Fuel Cells are ~60% efficient. With a waste heat recovery turbine, you increase the efficiency. 75% efficiency is already feasible. https://www.sciencedirect.com/science/article/abs/pii/S0306261918310316?via%3Dihub https://www.sciencedirect.com/science/article/abs/pii/S03062... Yes, this solution is more complex than a normal fuel cell...in exactly the same way that a turbocharged engine is more complex than a naturally aspirated engine. That is to say not only is it entirely feasible, but it is a well developed easily adaptible solution that has been used for increasing efficiency for over a century now. Learn how to google...there are literally hundreds of papers detailing efficiency gains from using turbochargers on fuel cells. Hell, most turbocharger manufacturers are already making custom hybrid turbocharger/generator packages specifically designed for fuel cell use. https://www.garrettmotion.com/electric-hybrid/twostage-electric-compressor-for-fuel-cells/ https://www.garrettmotion.com/electric-hybrid/twostage-elect... https://www.mtu-solutions.com/eu/en/stories/technology/turbochargers-for-higher-engine-efficiency.html https://www.mtu-solutions.com/eu/en/stories/technology/turbo... https://cdn.borgwarner.com/docs/default-source/default-document-library/2014_whitepaper_charging-system-for-fuel-cell-applications_en.pdf?sfvrsn=b60acd3c_11 https://cdn.borgwarner.com/docs/default-source/default-docum... You thought it was infeasible because you were imagining a big ass steam engine, and when it was pointed out that turbochargers are an entirely commonplace form of heat recovery turbine, you backpeddled and tried to redefine words (b-b-b-but that's a Turbo Compounder!!!) to weasel your way out of it. Give it up. You're embarrassing yourself.

SigmundA 5y ago
>If a modern heat recovery turbine is too complex, then so is an electric motor. A generator is bascially an electric motor running in reverse, at minimum you have a turbine and a generator to make a heat recovery turbine, or you can mechanically couple it with a transmission. That is more complex than just an electric motor, is this not obvious to you? The SOFC you linked at 75% efficiency uses a turbine with a secondary combustion chamber (post combustor) and along with a generator. Again this is not just a "simple" turbocharger. https://d3i71xaburhd42.cloudfront.net/3362b2a27c2ec1f3064114a66c9791721af69fe4/5-Figure1-1.png https://d3i71xaburhd42.cloudfront.net/3362b2a27c2ec1f3064114... Does that look like just a simple turbo charger? You are the one redefining what a heat recovery turbine is, no one calls a turbo charger a heat recovery turbine, and no devices called heat recovery turbines are just a turbo charger at minimum they drive a generator or are mechanically coupled to an engines output. So you have on one hand a: battery - motor controller - electric motor VS high pressure liquid H2 tanks - fuel cell - recovery turbine with generator - motor controller - electric motor Hopefully the fuel cell can have enough burst power for acceleration and not also need a buffer battery like current fuel cell EV's, then again you need a battery or regenerative braking, oh well. Which one is simpler and cheaper to fuel, maintain and operate? Which has more moving parts? Current fuel cells in cars don't even have an energy density advantage, maybe they will and will outpace batteries but they are certainly not simpler than a battery powered EV. Also stop being an ass, you are the one embarrassing yourself, at least try and keep it civil.
- darksaints 5y ago
  > Does that look like just a simple turbo charger? It doesn't look like a turbocharger, it looks like a system diagram of a fuel cell attached to a turbocharger. ::facepalm:: > You are the one redefining what a heat recovery turbine is, no one calls a turbo charger a heat recovery turbine, and no devices called heat recovery turbines are just a turbo charger at minimum they drive a generator or are mechanically coupled to an engines output. ::doublefacepalm::
  - SigmundA 5y ago