New type of boiler

A team at Warwick university have been working on a more economical air conditioning unit for cars, which they expect to be in production in four years. In so doing they realised that they can use the technique to design a new type of central heating boiler, which they claim will be at least 20% more economical than the best current model. This they expect to be in production within 2 years, let's hope that my current boiler will last that long!

Reply to
Broadback
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By gum, an current A rated boiler is 90% efficient so 20% on top of that will mean it will be printing money and not costing a thing to run ! ;-)

Gio

Reply to
Gio

My first thought as well but could the air conditioning unit link mean that some sort of heat pump technology is involved? Or is that thought just pie in the sky?

Reply to
Roger Chapman

Well, economical to me means the cost to run the thing. Efficiency means how much of what you put into it you get out as useful work.

I suspect it can still be just as "wasteful" in terms of what it loses to the atmosphere, but it does it on 20% less fuel compared to the current generation, so the cost savings will be significant (although I'm sure they'll put a hefty mark-up on the units themselves, so the actual savings won't be that much - just enough to convince people to buy their technology over the current stuff. Cynical, me :-)

cheers

Jules

Reply to
Jules

Doesn't mention efficiency. Says 20% more economical so means it uses less energy for a given output. I'll leave it to others to work out if such savings are possible with the current generation of boilers.;-)

Reply to
Dave Plowman (News)

It doesn't do a thing to a diesel. The economy only dives when you put AC on a small petrol engine.

Really! This is a standard homework question on a worksheet. The university doesn't sponsor people so it is all untested theory.

Really! AC has nothing to do with boilers. No wonder the university turns out so many confused people.

More than 100%? Can't wait to see that, a boiler that produces it's own power! Is it a nuclear powered combination boiler? Can't you tell they are students, they don't seem to know basic maths.

God help them if the lecturer asks the small group of homework people to prove this.

How long? 4 years, 2 years or 6 years?

Do us a favour, stop reproducing university homework question sheets.

Reply to
Roger

If the current generation can extract over 90% of the gross energy value of the fuel, then how would you propose using 20% less and still getting the same energy out?

It may be they are talking about a heat pump technology that can return a bigger multiple of energy moved vs energy put in.

Reply to
John Rumm

Ah, but maybe it runs on snake oil rather than gas?

Reply to
Roger Mills

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probably related to the OPs post.

Do not Google for "Warwick Boilers" unless you are into that sort of thing:-)

Adam

Reply to
ARWadsworth

Yes.

I was imagining something where current boilers burn "100 x" to do a job and "10 x" of that is wasted - and the new boiler burns "80 x" to do that same job and "8 x" is (e.g.) wasted; the new is 20% more economical because it uses 20% less fuel to do that same job, but it's still 90% efficient because the proportion of waste is still the same.

In other words I thought the 90% thing was a measure of efficiency purely in the combustion process - not necessarily an indication of how good the boiler was at transferring the heat to where it was needed. That's always been my assumption, but it is quite possibly wrong :-)

cheers

Jules

Reply to
Jules

almost certainly a heat pump in it then.

Depending on how you regard 'effiency' these are 300-400% 'efficient'

Reply to
The Natural Philosopher

I was looking at the coefficient of performance of an absoption chiller for a trawler, used waste heat from the diesel exhaust. It seemed to be about

0.75 so I suppose the overall thermal rejection was 1.75 of heat delivered to the unit. The boat of course had a massive heat sink right adjacent to it, this innovation seems to be in integrating the heat exchanger with the absorbent.

AJH

Reply to
andrew

A gas fridge, which is decades old technology is an absorption refrigeration system. They are making it smaller. It appears the COP has improved. An electric heat pump at COP 4 is the equivalent to gas to run as gas is about

1/4 of the price of electricity per kW. Now if this absorption unit is smaller and has say COP 2 running on gas then it looks good. A smaller unit using the waste heat from car exhausts may be feasible to cool. They can heat a house or hot water if reversed, that is all a heat pump does. The benefits are more for very hot countries.

This has been looked at for a number of years now. US car makers have been wanting small absorption units for a long time. I think a Cadillac had one.

This looks good and should drop heating bills using absorption heat pumps run on cheap gas, even on air-to-air units. Having them ground sourced, or better water sourced, I'm sure an oil version will be available.

Reply to
Doctor Drivel

Of course it does. AC compressors take power and it has to be paid for. Unlike car heating which comes from waste heat.

It make makes a bigger percentage difference on a small economical engine.

Reply to
Dave Plowman (News)

Drivel detected. Everything you take off the crank consumes horse power or now kW.

Reply to
Doctor Drivel

Well if you think about it, if the process is 90% efficient - 10% is lost out the flue, and 90% stays in the house where you want it. (in fact you can do better than 90% if you can run maximum condensing efficiency all the time; 96% is about the theoretical max IIUC. 90% is a typical seasonally adjusted figure. Add some weather compensation and you can also reduce the heating load a little by removing unwanted overshoots and reducing overheating. Not a massive gain on modern boilers but worth having in some cases.

Reply to
John Rumm

There is an interesting development on recovery of hitherto unusable low grade heat, which may prove quite handy if it can be made to work:

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Reply to
John Rumm

Maybe this will help:

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Reply to
Donwill

And a car has the atmosphere whooshing past at 60mph for the same purpose.

However this boiler for a house probably still requires a paddock sized array of coiled pipes as a ground heat source.

Reply to
Andy Burns

In my ignorance I assumed the heat source was still the mass flow of the flue gases, i.e. the hot and cold sides were incorporated inside the boiler. I imagined this would limit the cold side to 0C, so with the heating circuit return flow being in the order of 50C the heat gained would be limited to the specific heat of the flue massflow times 50 degrees.

AJH

Reply to
andrew

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