Member Info for Phimx

Oldblue: how will In-spirit produce 75 HP from their 10.3 HP Stirling to improve a D13 by 20%

You don't have a clue do you ?

Oldblue: where does the 75 HP come from??

To others: it seems obvious to me that the In-spirit Stirling had its efficiency increased by 20%. Perhaps we could have guessed that. So what we know is if we blow the exhaust from a 375 HP engine costing £60,000 we can get an extra 1.28 kW from In-spirit's Stirling engine. But what do Volvo get ? An extra 2.75% efficiency, pretty poor improvement considering the additional cost and weight.

Oldblue: you wrote
"looks like they tried a rankine and only got 6.7% efficency table 4.10?
from below looks like they have done the same process and got 20% and that was 3rd nov 2020"

So you are saying In-spirit increased the D13 efficiency by 20%. So the Stirling produced 75 HP from the waste heat i.e 20% of 375 HP.
Where did In-spirit get this huge amount of electricity from, it certainly wasn't from the only Stirling they have been supposedly developing for the last 10 years, which supposedly develops 10.3 HP ????

It was all a modelling exercise. Now to produce that 75 HP they need to design a far bigger Stirling..... From scratch.

Oldblue: Read In-spirit's words
" During the demonstration, the novel three stage heat recycling process increased engine efficiency by approximately 20% ...

Engine efficiency increased by 20%

You waffle on about heat exchangers, they aren't mentioned.

Which engine efficiency increased by 20%. The Stirling or the D13 ??????????????

Try and put together a coherent answer i.e.

The Stirling
or
The D13

Oldblue: I think I'll let others decide who is the fool.

Oldblue: You write

“AND THIS ONE TO HOW DID YOU COME TO THIS DETAILED CALCS PLS

1.A 20% INCREASE IN OUTPUT FROM IN-SPIRIT'S STIRLING, TO 7.68 KW, CAN ONLY IMPROVE THE 375 HP D13 BY 2.7% . THE PAPER YOU CITE, A THEORETICAL WHR PROPOSITION, IMPROVES EFFICIENCY BY 6.7%”

Admittedly if you have trouble with simple percentages this might cause you a lot of grief. So now we have established that the Charger output has increased by 20% to 7.68 kW, how does that affect the D13.

Well the purpose of using the Stirling engine/Charger is to gain some additional useful work from the huge amount of energy that is blown out of the exhaust to the atmosphere. Are following ?

Since the Stirling can produce a total of 7.68 kW from this waste heat, it adds to the output from the D13 without using additional fuel.

Now another one of those tricky percentages coming up.

The D13 produces 375 HP from the lowest power output engine. Now go online and find out what 1 horse power is in Watts. I’ll save you the bother, you may spend all day doing that. 1 Horse Power = 745 W. So how many HP is 7.68 kW. Very tricky, watch carefully
7680/745 = 10.3 HP. Very sly of me, I changed kW to Watts.

Voila, the Stirling produces 10.3 HP. Now that represents … percentage alert...

10.3/375 = 2.75 %

So the D13 has produced an additional 2.75% more output by adding the Stirling.

So the next big problem, at least for you ! If you wanted to increase the output of the D13 by 20% how much electricity would the Stirling have to produce.

Percentage alert … 20% of 375 HP = 75 HP. We need a Stirling from In-spirit to produce 75 HP. BUT in-spirit don’t Have such a thing, they only have a device purportedly producing 10.3 HP. They would need to start all over again and design a massive Stirling engine and they are incapable of that!

Oldblue: You write “ so how did you get the 7.76kw? detalied calcs pls”

Are you saying you cannot figure out where 7.76 kW came from? You want detailed calcs of 20% of 6.4 kW ? I think this is maths for 10 or 11 year olds.

You also write “ how did you figure out the burner for the charger is 100 kg” The answer is in my post it says “the Charger weighs 350 kg but you don't need the burner. So a wild guess, 250 kg”

Do you understand what a wild guess is ?

Come on Oldblue stop sulking, tell the board why my posts are rubbish. Explain why my figures are rubbish. The board is waiting with bated breath.

Come on son give it all you've got !

Oldblue: where did you get the information that Volvo first approached In-spirit. ?????
Give us the reference.

Come on son, you are full of it, spit it out.

Dispute the simple calculations, you keep saying it's rubbish well show everyone it's rubbish. Come on son do your worst.

Inspirit were quick to claim the mCHP was successfully trialled by the Carbon Trust. But In the report was not a single mention of the mCHP performance or what their device achieved.

Oldblue: I say you can not show that's incorrect. Put up or shut up !

2. To increase the D13 by 20% requires a Stirling with an output of 55.93 kW, approximately a 9 fold output of the existing in-spirit Stirling. Totally impossible !

It is that simple. Show me I'm wrong !!!!!!!!!!!!

Oldblu :You WILL be confused by the message being split accidentally. My last 2 sentence were meant to be.

"And no, I'm not suggesting this massive Stirling goes in the exhaust. Correct my thinking if it's wrong instead throwing insults"

As usual I'll get no sensible reply from you.

1.A 20% increase in output from In-spirit's Stirling, to 7.68 kW, can only improve the 375 HP D13 by 2.7% . The paper you cite, a theoretical WHR proposition, improves efficiency by 6.7%

Oldblue: and what exactly is wrong with my thoughts ?

Stirling goes in the exhaust. Correct my thinking if it's wrong instead throwing insults

Oldblue: Rankine, Stirling totally irrelevant. You were implying because only 6.7% was achievable they came to In-spirit. But, the current WHR system i.e. the Stirling will only give them 7.76 kW a pathetic 2.7% improvement. Let's consider weight and i'll be generous, for 7.76 kW the Charger weighs 350 kg but you don't need the burner. So a wild guess, 250 kg. Now just assuming weight scales with output, then to increase the D13 output by 20% would require a new In-spirit model weighing roughly 2000 kg. That is more than the D13 itself. And no, I'm not suggesting this massive

Oldblue: Here we go again.....yawn. you wrote
**********
they came to us nov 2019 just after as it looks they could only get max 6.7% out table 4.10
**********
If you care to read my fag packet calculations below, you will see that In-spirit claimed their Stirling produced an additional 20% when powered from a D13. Therefore the D13 output could be increased by 7.76 kW or in percentage terms 2.7%. JUST FOR YOU 2.7 IS LESS THAN 6.7.Now, if you were to argue it was the D13 output that was increased by 20% then it's output needs to increase by 55.93 kW for the 375 HP model. This leads to the conclusion that an In-spirit Stirling rated at 55.93 kW would have to be driven by the D13. Now since the only Stirling In-spirit have is a tiny 6.4 kW device - supposedly, then a totally new totally larger Stirling would need to be designed, built and tested. Since they have failed to achieve that task with the 6.4 kW device they were handed on a plate 10 long years ago, then you can guess my conclusion ..........NO ******* CHANCE.

Oldblue. Here is my answer to my question,since you are unable to answer.
************

“During the demonstration, the novel three stage heat recycling process increased engine efficiency by approximately 20%, driven by waste heat from e.g. a Volvo Penta D13 series engine. In addition to the efficiency improvement and heat reduction, the WHR system is also expected to have the additional significant benefit of reducing noise”

Which engine? The Volvo D13 or Inspirit’s Stirling ?

Wiki: The D13 has an output of between 375 – 500 HP. Increasing the D13 efficiency by 20% would require additional output of 75 HP for the 375 HP variant. From my school physics book that’s an extra 55.93 kW ( 1HP = 745.7 W)

The Stirling has a puny 6.4 kW output. There is no known 56 kW Stirling, so it can’t be that !

The alternative is the Stirling engine output increased by 20%, so - 7.76 kW.

Thus the D13 efficiency increases by 7.76 kW/279.64 kW = 2.77% - by adding the Stirling.

I doubt Volvo would really give a xxxx that the Inspirit’s Stirling efficiency increased by 20 % when driven by the huge amount of heat from a D13. So the only thing of interest to them is the 2.77% increased efficiency of the D13.

But, the cost ?

The Charger weighs 350 kg, the D13 1182 kg. Thus the Volvo system weight increases by 29.6% for an increase in efficiency of 2.77% and an obvious significant increase in the integrated system financial cost

Volvo don’t seem to get much out of this proposal !!!

That’s not to mention reliability, how long the Stirling engine would last with a large increase in operating temperature to produce the 7.76 kW ??

For the 500 HP the extra D13 efficiency would be 2.1%