Home |
Search |
Today's Posts |
#1
Posted to uk.d-i-y
|
|||
|
|||
'Steam' powered cars...
In Autocar this week.
BMW are experimenting with using the waste heat from an IC engine to produce steam which drives a motor attached to the main engine. On the test bed they're getting a 15% saving in fuel consumption - at the same time as more power and torque. Seems it's not a new idea, but BMW reckon it is practical and should be in production within 10 years. -- *If you think nobody cares about you, try missing a couple of payments * Dave Plowman London SW To e-mail, change noise into sound. |
#2
Posted to uk.d-i-y
|
|||
|
|||
'Steam' powered cars...
Dave Plowman (News) wrote:
In Autocar this week. BMW are experimenting with using the waste heat from an IC engine to produce steam which drives a motor attached to the main engine. On the test bed they're getting a 15% saving in fuel consumption - at the same time as more power and torque. Seems it's not a new idea, but BMW reckon it is practical and should be in production within 10 years. When I was a nipper my old man was a tinkerer in electric motors and generators and although this is very vague he put together on a piece of wood a small cycle light generator a 12 or 24 volt motor(?) and rechargable battery connected together whereby the battery started the motor which in turn rotated the generator wheel thus fed power to the battery for charging purposes, obviously there was some electronics in between which as i said was very vague recollection -- Sir Benjamin Middlethwaite |
#3
Posted to uk.d-i-y
|
|||
|
|||
'Steam' powered cars...
The3rd Earl Of Derby wrote:
Dave Plowman (News) wrote: In Autocar this week. BMW are experimenting with using the waste heat from an IC engine to produce steam which drives a motor attached to the main engine. On the test bed they're getting a 15% saving in fuel consumption - at the same time as more power and torque. Seems it's not a new idea, but BMW reckon it is practical and should be in production within 10 years. When I was a nipper my old man was a tinkerer in electric motors and generators and although this is very vague he put together on a piece of wood a small cycle light generator a 12 or 24 volt motor(?) and rechargable battery connected together whereby the battery started the motor which in turn rotated the generator wheel thus fed power to the battery for charging purposes, obviously there was some electronics in between which as i said was very vague recollection http://en.wikipedia.org/wiki/Perpetual_motion Alas, not. However, the BMW gadget suffers from none of this - car engines are quite inefficient (thermodynamically), and the exhaust temperature (at the exhaust valve) is around 700C. Current car engines are about 25% at best efficient, so 75% of power goes out the exhaust pipe wasted. Theoretically, about 66% of this could be recovered by a completely efficient heat engine, but in practice, even large power stations only get about 50%, and they start off a bit hotter, as well as having ready access to cooling water. 10% is probably achievable - in the long term, for maybe a recovery of 7.5%, or a gain in efficiency of 30%. This means however major additional systems such as much, much bigger radiators. |
#4
Posted to uk.d-i-y
|
|||
|
|||
'Steam' powered cars...
"Ian Stirling" wrote in message
... The3rd Earl Of Derby wrote: Dave Plowman (News) wrote: In Autocar this week. BMW are experimenting with using the waste heat from an IC engine to produce steam which drives a motor attached to the main engine. On the test bed they're getting a 15% saving in fuel consumption - at the same time as more power and torque. Seems it's not a new idea, but BMW reckon it is practical and should be in production within 10 years. When I was a nipper my old man was a tinkerer in electric motors and generators and although this is very vague he put together on a piece of wood a small cycle light generator a 12 or 24 volt motor(?) and rechargable battery connected together whereby the battery started the motor which in turn rotated the generator wheel thus fed power to the battery for charging purposes, obviously there was some electronics in between which as i said was very vague recollection http://en.wikipedia.org/wiki/Perpetual_motion Alas, not. However, the BMW gadget suffers from none of this - car engines are quite inefficient (thermodynamically), and the exhaust temperature (at the exhaust valve) is around 700C. Current car engines are about 25% at best efficient, so 75% of power goes out the exhaust pipe wasted. Theoretically, about 66% of this could be recovered by a completely efficient heat engine, but in practice, even large power stations only get about 50%, and they start off a bit hotter, as well as having ready access to cooling water. 10% is probably achievable - in the long term, for maybe a recovery of 7.5%, or a gain in efficiency of 30%. This means however major additional systems such as much, much bigger radiators. Best cars, maybe 18% efficiency, power stations lucky if 25%, fluidised coal bed stations can reach 33% efficiency. |
#5
Posted to uk.d-i-y
|
|||
|
|||
'Steam' powered cars...
On Wed, 21 Dec 2005 14:11:42 +0000 (GMT), "Dave Plowman (News)"
wrote: BMW are experimenting with using the waste heat from an IC engine to produce steam which drives a motor attached to the main engine. http://www.gizmag.co.uk/go/4936/ |
#6
Posted to uk.d-i-y
|
|||
|
|||
'Steam' powered cars...
Best cars, maybe 18% efficiency, power stations lucky if 25%, fluidised
coal bed stations can reach 33% efficiency. Can't remember the formulae following the Xmas lunch, but I think modern coal/oil plant is knocking on 40% and CCGT more like 50 |
#7
Posted to uk.d-i-y,uk.rec.cars.maintenance
|
|||
|
|||
'Steam' powered cars...
Ian Stirling wrote:
Current car engines are about 25% at best efficient, so 75% of power goes out the exhaust pipe wasted. I thought most was lost through the radiator. |
#8
Posted to uk.d-i-y
|
|||
|
|||
'Steam' powered cars...
Andy Dingley wrote: BMW are experimenting with using the waste heat from an IC engine to produce steam which drives a motor attached to the main engine. http://www.gizmag.co.uk/go/4936/ Looking at the pics ( which aren't very clear & I haven't spent very long looking) it seems they're using the heat from the catalytic converter as a superheater. My understanding was that a catalytic converter increased fuel consumption by about 10%, whilst the heat generated in catalysing CO into CO2 was sufficient to make it a fire hazard in dry grass. So now the Germans have added on a steam engine which recovers 10% of the efficiency. I saw Maggie Thatcher (ex industrial chemist) on TV ranting about catalytic converters, the only time I heard her speak sense. A more cost-effective method of reducing emissions was the lean-burn engine, which was both more efficient and less polluting that an un-catted engine. I believe Rover had done much development on the lean-burn technology, but that seems to have been scuttled after BMW's brief period at the helm. |
#9
Posted to uk.d-i-y,uk.rec.cars.maintenance
|
|||
|
|||
'Steam' powered cars...
"Chris Bacon" wrote in message ... Ian Stirling wrote: Current car engines are about 25% at best efficient, so 75% of power goes out the exhaust pipe wasted. I thought most was lost through the radiator. If the head gasket goes on any car, you could sa it is steam powered..! ) |
#10
Posted to uk.d-i-y
|
|||
|
|||
'Steam' powered cars...
On Wed, 21 Dec 2005 16:58:29 -0000, "Ian_m" wrote:
"Ian Stirling" wrote in message ... The3rd Earl Of Derby wrote: Dave Plowman (News) wrote: In Autocar this week. BMW are experimenting with using the waste heat from an IC engine to produce steam which drives a motor attached to the main engine. On the test bed they're getting a 15% saving in fuel consumption - at the same time as more power and torque. Seems it's not a new idea, but BMW reckon it is practical and should be in production within 10 years. When I was a nipper my old man was a tinkerer in electric motors and generators and although this is very vague he put together on a piece of wood a small cycle light generator a 12 or 24 volt motor(?) and rechargable battery connected together whereby the battery started the motor which in turn rotated the generator wheel thus fed power to the battery for charging purposes, obviously there was some electronics in between which as i said was very vague recollection http://en.wikipedia.org/wiki/Perpetual_motion Alas, not. However, the BMW gadget suffers from none of this - car engines are quite inefficient (thermodynamically), and the exhaust temperature (at the exhaust valve) is around 700C. Current car engines are about 25% at best efficient, so 75% of power goes out the exhaust pipe wasted. Theoretically, about 66% of this could be recovered by a completely efficient heat engine, but in practice, even large power stations only get about 50%, and they start off a bit hotter, as well as having ready access to cooling water. 10% is probably achievable - in the long term, for maybe a recovery of 7.5%, or a gain in efficiency of 30%. This means however major additional systems such as much, much bigger radiators. Best cars, maybe 18% efficiency, power stations lucky if 25%, fluidised coal bed stations can reach 33% efficiency. What class of power station? Coal fired steam turbine with/without passout, gas turbine, gas turbine with cogen, Low speed heavy fuel diesel engine with waste heat recovery,? There are many combinations the most efficient of which is likely the slow speed heavy oil diesel engine with waste heat recovery that will exceed 50% efficiency, however, this type of generation is not, I believe, used in the UK. Industrial gas turbine with cogen is probably a very close second, again with 50% plus efficiency. |
#11
Posted to uk.d-i-y
|
|||
|
|||
'Steam' powered cars...
In article .com,
Aidan wrote: My understanding was that a catalytic converter increased fuel consumption by about 10%, whilst the heat generated in catalysing CO into CO2 was sufficient to make it a fire hazard in dry grass. So now the Germans have added on a steam engine which recovers 10% of the efficiency. Nothing like 10% with a modern cat. I saw Maggie Thatcher (ex industrial chemist) on TV ranting about catalytic converters, the only time I heard her speak sense. A more cost-effective method of reducing emissions was the lean-burn engine, which was both more efficient and less polluting that an un-catted engine. I believe Rover had done much development on the lean-burn technology, but that seems to have been scuttled after BMW's brief period at the helm. Rover never produced a lean burn engine - although they may have researched it. Indeed, they limped on with carburettors long after everyone had gone to EFI - not surprising since they owned SU carburettors. Even although they produced the first EFI equipped UK model in the SD1 Vitesse and it was obvious then this was the way to go. -- *Certain frogs can be frozen solid, then thawed, and survive * Dave Plowman London SW To e-mail, change noise into sound. |
#12
Posted to uk.d-i-y
|
|||
|
|||
'Steam' powered cars...
Aidan wrote:
I saw Maggie Thatcher (ex industrial chemist) on TV ranting about catalytic converters, the only time I heard her speak sense. A more cost-effective method of reducing emissions was the lean-burn engine, which was both more efficient and less polluting that an un-catted engine. I believe Rover had done much development on the lean-burn technology, but that seems to have been scuttled after BMW's brief period at the helm. "Europe" followed legislation implemented in California, to cause a horrendous own-goal re. environmental impact. Catalytic converters have little place in motoring in the UK. |
#13
Posted to uk.d-i-y
|
|||
|
|||
'Steam' powered cars...
On Thu, 22 Dec 2005 10:24:54 +0000, Chris Bacon
wrote: | Aidan wrote: | I saw Maggie Thatcher (ex industrial chemist) on TV ranting about | catalytic converters, the only time I heard her speak sense. A more | cost-effective method of reducing emissions was the lean-burn engine, | which was both more efficient and less polluting that an un-catted | engine. I believe Rover had done much development on the lean-burn | technology, but that seems to have been scuttled after BMW's brief | period at the helm. | | "Europe" followed legislation implemented in California, to | cause a horrendous own-goal re. environmental impact. Catalytic | converters have little place in motoring in the UK. IIRC only the maximum emissions of cars are limited, there is nothing to say you *must* have catalytic converters. -- Dave Fawthrop hyphen Hyphenologist.co.uk Register your mobile phone IMEI *free* on http://www.menduk.org/. Keep the username and password. If it gets stolen report it your provider to get it blocked. To hopefully get it back report on http://www.menduk.org/ or 08701 123 123. |
#14
Posted to uk.d-i-y
|
|||
|
|||
'Steam' powered cars...
On 21 Dec 2005 16:41:05 -0800, "Aidan" wrote:
I saw Maggie Thatcher (ex industrial chemist) on TV ranting about catalytic converters, the only time I heard her speak sense. A more cost-effective method of reducing emissions was the lean-burn engine, For late-80s designs of catalyst, and for late-80s Ford-based predictions of lean burn engines. Catalysts are much less restrictive now than they were then. The Yanks put up with rubbish for 20 years and just threw a few more cylinders at the problem. Europe wouldn't, so we fixed it. As for lean-burn, then much of the hype over it came from Ford, who were themselves being hoodwinked by outsourced R&D to a bunch of cowboys. A particular cowboy in fact who nicked my '50s edition of Ricardo. *******. |
#15
Posted to uk.d-i-y
|
|||
|
|||
'Steam' powered cars...
On Thu, 22 Dec 2005 09:12:59 +0000 (GMT), "Dave Plowman (News)"
wrote: Indeed, they limped on with carburettors long after everyone had gone to EFI - not surprising since they owned SU carburettors. Nothing wrong with carburettors (as Rover developed them) in terms of performance, just the problems of extra cost, complexity and (mainly) poor performance in later life. EFI is _very_ cheap to make these days - hardly any expensive machining and we all know what Moore's law did to anything needing the electronic smarts of the average GameBoy. |
#16
Posted to uk.d-i-y
|
|||
|
|||
'Steam' powered cars...
In article ,
Andy Dingley wrote: Indeed, they limped on with carburettors long after everyone had gone to EFI - not surprising since they owned SU carburettors. Nothing wrong with carburettors (as Rover developed them) in terms of performance, just the problems of extra cost, complexity and (mainly) poor performance in later life. The last versions with ECU controlled mixture and idle speed in an attempt to control emissions were hardly paragons of reliability - although they did work ok when they worked. However, must have come very close to the cost of decent EFI, so really rather pointless. EFI is _very_ cheap to make these days - hardly any expensive machining and we all know what Moore's law did to anything needing the electronic smarts of the average GameBoy. True. Or would,be if I knew what Moore's law was. ;-) -- *Why can't women put on mascara with their mouth closed? Dave Plowman London SW To e-mail, change noise into sound. |
#17
Posted to uk.d-i-y
|
|||
|
|||
'Steam' powered cars...
In article ,
Chris Bacon wrote: I saw Maggie Thatcher (ex industrial chemist) on TV ranting about catalytic converters, the only time I heard her speak sense. A more cost-effective method of reducing emissions was the lean-burn engine, which was both more efficient and less polluting that an un-catted engine. I believe Rover had done much development on the lean-burn technology, but that seems to have been scuttled after BMW's brief period at the helm. "Europe" followed legislation implemented in California, to cause a horrendous own-goal re. environmental impact. Catalytic converters have little place in motoring in the UK. Yes they do - as anyone who walks close to town traffic will know. You can instantly tell an older non cat equipped car by the smell. And it's not pleasant. CO2 may be bad for global warming, but CO, NOX and hydrocarbons aren't pleasant at the point of emission. -- *I took an IQ test and the results were negative. Dave Plowman London SW To e-mail, change noise into sound. |
#18
Posted to uk.d-i-y
|
|||
|
|||
'Steam' powered cars...
Dave Plowman (News) wrote:
Chris Bacon wrote: Aiden wrote, but the DP munged the attributions: catalytic converters, the only time I heard her speak sense. A more cost-effective method of reducing emissions was the lean-burn engine, which was both more efficient and less polluting that an un-catted engine. I believe Rover had done much development on the lean-burn technology, but that seems to have been scuttled after BMW's brief period at the helm. "Europe" followed legislation implemented in California, to cause a horrendous own-goal re. environmental impact. Catalytic converters have little place in motoring in the UK. Yes they do - as anyone who walks close to town traffic will know. You can instantly tell an older non cat equipped car by the smell. And it's not pleasant. This is rubbish. Most cars are used for short journeys, during which their catalytic converters do not work properly. There's also another potential health problem in that masses of finely- divided platinum is now being deposited all over the place. CO2 may be bad for global warming, but CO, NOX and hydrocarbons aren't pleasant at the point of emission. What does a catalytic converter spit out then it's not yet functioning well? Perhaps you'd like to transfer this (or x-psot) to a relevant car-related NG. |
#19
Posted to uk.d-i-y
|
|||
|
|||
'Steam' powered cars...
Huge wrote:
[...] manufacturers [...] charging ridiculous amounts of money for ECUs. Like over £400 for an Isuzu one on an Astra, fixed very easily (thankfully) after a quick Google, and the application of a soldering iron, for a cost of approx. 0. |
#20
Posted to uk.d-i-y
|
|||
|
|||
'Steam' powered cars...
Not that that stops the manufacturers from charging ridiculous amounts
of money for ECUs. Likewise the prices garages charge(d) for diagnosis on their computer diagnosis machines. I had an intermittant fault on a Rover years ago, They wanted to charge 60 quid / hour with the car on "soak test" until the fault appeared. They would have happily charged me about 1000 quid for the process ! Simon. |
#21
Posted to uk.d-i-y
|
|||
|
|||
'Steam' powered cars...
The last versions with ECU controlled mixture and idle speed in an attempt
to control emissions were hardly paragons of reliability - although they did work ok when they worked. However, must have come very close to the cost of decent EFI, so really rather pointless. I had one. After a run on the motorway, the pin that controlled the idle speed would get stuck, such that you would enter a village, pull up at a zebra crossing, and some old lady would get terrified by a car revving like a maniac. And the whole high street turned to look at me like the joy riders had entered town. I had to stop and restart the car to reboot the system ! Simon. |
#22
Posted to uk.d-i-y
|
|||
|
|||
'Steam' powered cars...
In article ,
Chris Bacon wrote: Yes they do - as anyone who walks close to town traffic will know. You can instantly tell an older non cat equipped car by the smell. And it's not pleasant. This is rubbish. Most cars are used for short journeys, during which their catalytic converters do not work properly. It would have to be a *very* short journey indeed. Most these days light up very quickly. There's also another potential health problem in that masses of finely- divided platinum is now being deposited all over the place. You'd prefer lead? And in *vastly* greater quantities? CO2 may be bad for global warming, but CO, NOX and hydrocarbons aren't pleasant at the point of emission. What does a catalytic converter spit out then it's not yet functioning well? See above. But the same as a non cat engine. Perhaps you'd like to transfer this (or x-psot) to a relevant car-related NG. Err, I didn't start the cat. business. I thought the development by BMW about using waste heat might be of interest on here. -- *I don't know what your problem is, but I'll bet it's hard to pronounce Dave Plowman London SW To e-mail, change noise into sound. |
#23
Posted to uk.d-i-y,uk.transport
|
|||
|
|||
'Steam' powered cars...
Dave Plowman (News) wrote:
Chris Bacon wrote: Someone else wrote, but DP munged the attributions again: Someone else wrote, but DP munged the attributions again: [ Catalytic converters have little place in motoring in the UK. ] Yes they do - as anyone who walks close to town traffic will know. You can instantly tell an older non cat equipped car by the smell. And it's not pleasant. This is rubbish. Most cars are used for short journeys, during which their catalytic converters do not work properly. It would have to be a *very* short journey indeed. Most these days light up very quickly. How short a journey? There's also another potential health problem in that masses of finely- divided platinum is now being deposited all over the place. You'd prefer lead? And in *vastly* greater quantities? I didn't mention lead, just that finely divided platinum is being emitted all over the place. Incidentally, lead-free fuel is quite capable of being used in non-cat. cars, so I'm not sure what your comment pertains to. CO2 may be bad for global warming, but CO, NOX and hydrocarbons aren't pleasant at the point of emission. What does a catalytic converter spit out then it's not yet functioning well? See above. But the same as a non cat engine. With any reduction in fuel economy? Perhaps you'd like to transfer this (or x-psot) to a relevant car-related NG. Err, I didn't start the cat. business. I thought the development by BMW about using waste heat might be of interest on here. My guess it's better off in a car/transport NG. Someone will be along in a minute to tell me, I daresay... |
#24
Posted to uk.d-i-y
|
|||
|
|||
'Steam' powered cars...
Dave Fawthrop wrote:
Chris Bacon wrote: | Aidan wrote: | I saw Maggie Thatcher (ex industrial chemist) on TV ranting about | catalytic converters, the only time I heard her speak sense. A more | cost-effective method of reducing emissions was the lean-burn engine, | which was both more efficient and less polluting that an un-catted | engine. I believe Rover had done much development on the lean-burn | technology, but that seems to have been scuttled after BMW's brief | period at the helm. | | "Europe" followed legislation implemented in California, to | cause a horrendous own-goal re. environmental impact. Catalytic | converters have little place in motoring in the UK. IIRC only the maximum emissions of cars are limited, there is nothing to say you *must* have catalytic converters. AFAIK all new cars made since January 1993 *must* have a catalytic converter fitted. Europead directive blah, unless it's only UK law, which I doubt. |
#25
Posted to uk.d-i-y,uk.rec.cars.maintenance
|
|||
|
|||
'Steam' powered cars...
On Wed, 21 Dec 2005 23:00:38 +0000, Chris Bacon
wrote: Ian Stirling wrote: Current car engines are about 25% at best efficient, so 75% of power goes out the exhaust pipe wasted. I thought most was lost through the radiator. Cars are about 30% efficient at peak, usual operation is about 25%. Cooling power = engine power is reasonable rule of thumb and assume the remainder (33% up to 50%) goes down the exhaust pipe. Some of the cooling is direct to air from hot under bonnet surfaces. Not enough heat goes down exhaust pipe to run ancillaries at town road speeds and idle. 70mph only needs about 35bhp, so maybe as little as 35bhp or up to 50bhp goes to exhaust. They claim to extract 15% extra giving about 5bhp at 70mph which would just about do for the ancillaries but not with air-con. |
#26
Posted to uk.d-i-y
|
|||
|
|||
'Steam' powered cars...
In message , Edward W.
Thompson writes What class of power station? Coal fired steam turbine with/without passout, gas turbine, gas turbine with cogen, Low speed heavy fuel diesel engine with waste heat recovery,? There are many combinations the most efficient of which is likely the slow speed heavy oil diesel engine with waste heat recovery that will exceed 50% efficiency, however, this type of generation is not, I believe, used in the UK. Industrial gas turbine with cogen is probably a very close second, again with 50% plus efficiency. Baglan Bay in South Wales is the worlds most efficient (non-cogen) power station with an expected test efficiency of around 60% (Google GE 9H gas turbine), add in cogeneration and you can expect the thermal efficiency to exceed 70%. Your typical coal fired station like Drax or Didcot will be around 36% efficient. -- Andrew Sinclair http://www.smellycat.org |
#27
Posted to uk.d-i-y
|
|||
|
|||
'Steam' powered cars...
On Thu, 22 Dec 2005 20:01:40 +0000, news07 wrote:
Your typical coal fired station like Drax or Didcot will be around 36% efficient. Didcot isn't quite typical - it has long been used as a technology demonstrator for the latest in efficient turbine technologies. |
#28
Posted to uk.d-i-y,uk.transport
|
|||
|
|||
'Steam' powered cars...
Chris Bacon wrote:
My guess it's better off in a car/transport NG. Someone will be along in a minute to tell me, I daresay... transport group? wait for hours then three come at once... |
#29
Posted to uk.d-i-y
|
|||
|
|||
'Steam' powered cars...
In message , Andy Dingley
writes On Thu, 22 Dec 2005 20:01:40 +0000, news07 wrote: Your typical coal fired station like Drax or Didcot will be around 36% efficient. Didcot isn't quite typical - it has long been used as a technology demonstrator for the latest in efficient turbine technologies. Erm I worked at Didcot A (the coal fired one) for several years and the turbines there weren't anything special, run of the mill Parsons built AEI design. Over the fence at the gas fired B station it was the launch site for the Siemens V94.3a gas turbine which was pretty advanced in the mid-1990's but technology has moved on. Typically we refer to gas turbines in classes, the machines at Didcot B are F class, the GE machine at Baglan Bay is H class (there are G class machines out there but not many, mainly in the USA and Japan). Rugeley is just about the most efficient coal fired station in the UK, used to regularly win awards when the industry was nationalised. -- Andrew Sinclair http://www.smellycat.org |
#30
Posted to uk.d-i-y,uk.rec.cars.maintenance
|
|||
|
|||
'Steam' powered cars...
On Wed, 21 Dec 2005 23:00:38 +0000, Chris Bacon wrote:
Ian Stirling wrote: Current car engines are about 25% at best efficient, so 75% of power goes out the exhaust pipe wasted. I thought most was lost through the radiator. Nope. Exhaust. |
#31
Posted to uk.d-i-y
|
|||
|
|||
'Steam' powered cars...
On Thu, 22 Dec 2005 14:24:12 +0000 (GMT), Dave Plowman (News) wrote:
In article , Chris Bacon wrote: Yes they do - as anyone who walks close to town traffic will know. You can instantly tell an older non cat equipped car by the smell. And it's not pleasant. This is rubbish. Most cars are used for short journeys, during which their catalytic converters do not work properly. It would have to be a *very* short journey indeed. Most these days light up very quickly. I've had my big cat idling in te drive..it takes about 5 minutes or two miles before the smell of unburnt fuel goes away. Its only a mile down to the shop... There's also another potential health problem in that masses of finely- divided platinum is now being deposited all over the place. You'd prefer lead? And in *vastly* greater quantities? Lead free fuel is usable without a cat. Its the reverse that is not true. Incidentally, to ensure reliable starting most EFI systems flood the cold engine with fuel before starting. This has a HUGE impact on economy for short distance journeys, and, if it fails to start first time, can lead to a flooded engine. I know. I've done it. Its in this area that hybrids shoudl show the most gains. |
#32
Posted to uk.d-i-y
|
|||
|
|||
'Steam' powered cars...
On Fri, 23 Dec 2005 13:28:46 +0000, Andrew Sinclair
wrote: Didcot isn't quite typical - it has long been used as a technology demonstrator for the latest in efficient turbine technologies. Erm I worked at Didcot A (the coal fired one) for several years and the turbines there weren't anything special, run of the mill Parsons built AEI design. So what about the variable stators? Parsons were quite proud of them when they built them (retro-fit, not original). I worked on a vibration sensing project for them in the late '80s, detecting flutter in the blades. AIUI, the intention behind all this was to improve efficiency at startup, thus allowing the plant to be brought on and off load more quickly, without so much of the usual inefficiencies. |
#33
Posted to uk.d-i-y
|
|||
|
|||
'Steam' powered cars...
In article ,
The Natural Philosopher wrote: It would have to be a *very* short journey indeed. Most these days light up very quickly. I've had my big cat idling in te drive..it takes about 5 minutes or two miles before the smell of unburnt fuel goes away. Its only a mile down to the shop... Very bad idea running the car for such a short distance. Try and incorporate a trip to the shop with other things - or just walk there. There's also another potential health problem in that masses of finely- divided platinum is now being deposited all over the place. You'd prefer lead? And in *vastly* greater quantities? Lead free fuel is usable without a cat. I know that. However, those who are against cats/ tend also to hanker after the good ol' leaded petrol days... Its the reverse that is not true. Incidentally, to ensure reliable starting most EFI systems flood the cold engine with fuel before starting. This has a HUGE impact on economy for short distance journeys, and, if it fails to start first time, can lead to a flooded engine. I know. I've done it. Its in this area that hybrids shoudl show the most gains. The hybrid also has a petrol engine which has to be started from cold at some time or other. BTW, EFI systems don't, in my experience, flood the engine before starting. Until the ECU receives a signal from the crank sensor the injectors don't operate. -- *When I'm not in my right mind, my left mind gets pretty crowded * Dave Plowman London SW To e-mail, change noise into sound. |
#34
Posted to uk.d-i-y,uk.rec.cars.maintenance
|
|||
|
|||
'Steam' powered cars...
Chris Bacon wrote: Ian Stirling wrote: Current car engines are about 25% at best efficient, so 75% of power goes out the exhaust pipe wasted. I thought most was lost through the radiator. Strangely enough, cooling though the radiator is just as important as the heating in the combustion for achieving high efficiency. You can only extract mechanical energy between two temperatures; the larger the gap, the more efficient. |
#35
Posted to uk.d-i-y,uk.rec.cars.maintenance
|
|||
|
|||
'Steam' powered cars...
Johannes wrote:
Chris Bacon wrote: Ian Stirling wrote: Current car engines are about 25% at best efficient, so 75% of power goes out the exhaust pipe wasted. I thought most was lost through the radiator. Strangely enough, cooling though the radiator is just as important as the heating in the combustion for achieving high efficiency. You can only extract mechanical energy between two temperatures; the larger the gap, the more efficient. So what does the radiator cool that forms the 'cold' part of that pairing? |
#36
Posted to uk.d-i-y,uk.rec.cars.maintenance
|
|||
|
|||
'Steam' powered cars...
"PC Paul" wrote in message ... Johannes wrote: Chris Bacon wrote: Ian Stirling wrote: Current car engines are about 25% at best efficient, so 75% of power goes out the exhaust pipe wasted. I thought most was lost through the radiator. Strangely enough, cooling though the radiator is just as important as the heating in the combustion for achieving high efficiency. You can only extract mechanical energy between two temperatures; the larger the gap, the more efficient. So what does the radiator cool that forms the 'cold' part of that pairing? The driver's head? mrcheerful |
#37
Posted to uk.d-i-y,uk.rec.cars.maintenance
|
|||
|
|||
'Steam' powered cars...
mrcheerful . wrote:
"PC Paul" wrote in message ... Johannes wrote: Chris Bacon wrote: Ian Stirling wrote: Current car engines are about 25% at best efficient, so 75% of power goes out the exhaust pipe wasted. I thought most was lost through the radiator. Strangely enough, cooling though the radiator is just as important as the heating in the combustion for achieving high efficiency. You can only extract mechanical energy between two temperatures; the larger the gap, the more efficient. So what does the radiator cool that forms the 'cold' part of that pairing? The driver's head? I suspect that may be the case here. While the theory is basically sound, last time I looked my car didn't have a Stirling engine under the bonnet... Which recent cars do have chargecoolers, or even intake air coolers which are cooled by the rad? I know none of mine have... |
#38
Posted to uk.d-i-y,uk.rec.cars.maintenance
|
|||
|
|||
'Steam' powered cars...
On Fri, 23 Dec 2005 22:38:27 -0000, "PC Paul" wrote:
I suspect that may be the case here. While the theory is basically sound, last time I looked my car didn't have a Stirling engine under the bonnet... Which recent cars do have chargecoolers, or even intake air coolers which are cooled by the rad? I know none of mine have... Near enough all turbo charged cars including diesels! |
#39
Posted to uk.d-i-y,uk.rec.cars.maintenance
|
|||
|
|||
'Steam' powered cars...
In article ,
Johannes wrote: Strangely enough, cooling though the radiator is just as important as the heating in the combustion for achieving high efficiency. You can only extract mechanical energy between two temperatures; the larger the gap, the more efficient. That's a bit of an over simplification. Engines don't run at their most efficient until up to temperature. Probably to do with proper atomisation of the fuel. -- *Life is hard; then you nap Dave Plowman London SW To e-mail, change noise into sound. |
#40
Posted to uk.d-i-y,uk.rec.cars.maintenance
|
|||
|
|||
'Steam' powered cars...
On Sat, 24 Dec 2005 07:50:24 GMT, marb wrote:
Which recent cars do have chargecoolers, or even intake air coolers which are cooled by the rad? I know none of mine have... Near enough all turbo charged cars including diesels! Name one _car_ (as opposed to a boat) that uses a water-air intercooler. Intercoolers are reasonably common (although by no means "near enough all") but they're air-air intercoolers, not water-air. If you fit a water-air intercooler to a car, you'd just have to enlarge the radiator to dump the heat out that way. Space is tight under a bonnet, so they use air-air instead. The question here was radiator vs. exhaust, not radiator vs. exhaust vs. separate intercooler. |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Housing market is realy bucking up! | UK diy | |||
Setting steam boiler pressure cutoff | Home Repair | |||
Building a Steam Room | Home Repair | |||
Steam Bending Lumber - Any Good Sites | Woodworking | |||
FAQ - Steambending | Woodworking |