4 ms·

It's a turbine. It spins inside a housing. It has an input and an output. Modern turbines don't even have oil...they use ceramic air bearings that might need to

It's a turbine. It spins inside a housing. It has an input and an output. Modern turbines don't even have oil...they use ceramic air bearings that might need to be replaced sometime after you die.

SigmundA 5y ago
A turbine does nothing by itself again an absurd statement. A heat recovery turbine has a host of support systems to actually recover heat including a generator which is essentially an electric motor to capture electrical energy. I don't see a lot of gas turbines in various use around me, and the ones that are are quite expensive to fix. I do however see electric motors everywhere and they are extremely reliable and cheap.
- darksaints 5y ago
  Lol, there is no need to speculate about the practicality of heat recovery turbines in vehicles. They're already in use by millions of cars and trucks. Nearly every semi truck on the road has one...sometimes they have two! They're called turbochargers. More specifically, the heat recovery turbine is the exhaust-connected half of the turbocharger. Most car turbos drive air compressors to increase ICE efficiency (surplus electric power isn't so useful for ICE cars), but you can literally chop the turbocharger in half and attach an electric motor to the turbine shaft, and voila, now you have an electric heat recovery turbine. Were you actually thinking I was proposing attaching a steam turbine to a fuel cell? Lol. Can I subscribe to the Cult of Elon's Version of Facts? This is hilarious.
  - SigmundA 5y ago
    Turbo chargers are not heat recovery turbines they will not increase and engine thermal efficiency by any significant amount, diesels use turbo charging to increase power they are just as thermally efficient without them. In order to utilize the increased air mass that forced induction creates more fuel must be injected, this should be obvious. Most turbo chargers do not engage under light throttle. Turbo charger also adds significant cost and are not inexpensive to repair. An actual useful heat recovery turbine is much larger and more complicated, all of the examples of one attached to diesels or fuel cell are either steam turbines as is the case with the Freightliner SuperTruck [1] or full gas turbines as is the case with some fuel cell implementations and some of those also have a secondary steam turbine [2]. The Freightliner still has a turbo charger like any diesel along with a recovery steam turbine, much of the effective heat recovery comes from capturing heat from the engine block itself not just hot exhaust gas. Again your claim that a full heat recovery turbine is a simple as a electric motor is ABSURD. 1. https://www.ccjdigital.com/business/article/14931733/waste-heat-recovery-an-old-theory-finds-new-life-but-will-it-work-for-every-trucking-application https://www.ccjdigital.com/business/article/14931733/waste-h... 2. https://www.ee.co.za/article/co-generation-hybrid-fuel-cell-gas-turbine-systems.html https://www.ee.co.za/article/co-generation-hybrid-fuel-cell-...
    - darksaints 5y ago
      > Turbo chargers are not heat recovery turbines they will not increase and engine thermal efficiency by any significant amount, diesels use turbo charging to increase power they are just as thermally efficient without them. This is 100% false, and trivially easy to google. But it also misses the point: turbochargers are heat engines: they convert heat to work. The fact that they use waste heat from exhaust means that they recover energy that is normally lost, which means it is a heat recovery engine. That work can be used any number of ways, but if it is used, you have increased the thermal efficiency of the engine. > The Freightliner still has a turbo charger like any diesel along with a recovery steam turbine, much of the effective heat recovery comes from capturing heat from the engine block itself not just hot exhaust gas. Those are both heat recovery engines. One is rankine cycle (the steam turbine), and the other is brayton cycle (the turbocharger). The only other difference is the source of heat. And again, to drive the point home: https://www.sciencedirect.com/science/article/pii/S1876610214014076/pdf?md5=81032aa431f1a3baea977a5b8820409a&pid=1-s2.0-S1876610214014076-main.pdf https://www.sciencedirect.com/science/article/pii/S187661021...
      - SigmundA 5y ago
        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/

It's a turbine. It spins inside a housing. It has an input and an output. Modern turbines don't even have oil...they use ceramic air bearings that might need to be replaced sometime after you die.

SigmundA 5y ago

A turbine does nothing by itself again an absurd statement. A heat recovery turbine has a host of support systems to actually recover heat including a generator which is essentially an electric motor to capture electrical energy. I don't see a lot of gas turbines in various use around me, and the ones that are are quite expensive to fix. I do however see electric motors everywhere and they are extremely reliable and cheap.

darksaints 5y ago
Lol, there is no need to speculate about the practicality of heat recovery turbines in vehicles. They're already in use by millions of cars and trucks. Nearly every semi truck on the road has one...sometimes they have two! They're called turbochargers. More specifically, the heat recovery turbine is the exhaust-connected half of the turbocharger. Most car turbos drive air compressors to increase ICE efficiency (surplus electric power isn't so useful for ICE cars), but you can literally chop the turbocharger in half and attach an electric motor to the turbine shaft, and voila, now you have an electric heat recovery turbine. Were you actually thinking I was proposing attaching a steam turbine to a fuel cell? Lol. Can I subscribe to the Cult of Elon's Version of Facts? This is hilarious.
- SigmundA 5y ago
  Turbo chargers are not heat recovery turbines they will not increase and engine thermal efficiency by any significant amount, diesels use turbo charging to increase power they are just as thermally efficient without them. In order to utilize the increased air mass that forced induction creates more fuel must be injected, this should be obvious. Most turbo chargers do not engage under light throttle. Turbo charger also adds significant cost and are not inexpensive to repair. An actual useful heat recovery turbine is much larger and more complicated, all of the examples of one attached to diesels or fuel cell are either steam turbines as is the case with the Freightliner SuperTruck [1] or full gas turbines as is the case with some fuel cell implementations and some of those also have a secondary steam turbine [2]. The Freightliner still has a turbo charger like any diesel along with a recovery steam turbine, much of the effective heat recovery comes from capturing heat from the engine block itself not just hot exhaust gas. Again your claim that a full heat recovery turbine is a simple as a electric motor is ABSURD. 1. https://www.ccjdigital.com/business/article/14931733/waste-heat-recovery-an-old-theory-finds-new-life-but-will-it-work-for-every-trucking-application https://www.ccjdigital.com/business/article/14931733/waste-h... 2. https://www.ee.co.za/article/co-generation-hybrid-fuel-cell-gas-turbine-systems.html https://www.ee.co.za/article/co-generation-hybrid-fuel-cell-...
  - darksaints 5y ago
    > Turbo chargers are not heat recovery turbines they will not increase and engine thermal efficiency by any significant amount, diesels use turbo charging to increase power they are just as thermally efficient without them. This is 100% false, and trivially easy to google. But it also misses the point: turbochargers are heat engines: they convert heat to work. The fact that they use waste heat from exhaust means that they recover energy that is normally lost, which means it is a heat recovery engine. That work can be used any number of ways, but if it is used, you have increased the thermal efficiency of the engine. > The Freightliner still has a turbo charger like any diesel along with a recovery steam turbine, much of the effective heat recovery comes from capturing heat from the engine block itself not just hot exhaust gas. Those are both heat recovery engines. One is rankine cycle (the steam turbine), and the other is brayton cycle (the turbocharger). The only other difference is the source of heat. And again, to drive the point home: https://www.sciencedirect.com/science/article/pii/S1876610214014076/pdf?md5=81032aa431f1a3baea977a5b8820409a&pid=1-s2.0-S1876610214014076-main.pdf https://www.sciencedirect.com/science/article/pii/S187661021...
    - SigmundA 5y ago
      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/