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Re: Circulating water requirements
Posted: Wed Mar 30, 2016 10:48 pm
by Dhutch
barts wrote: If you can post the cooling water (in and out) temps as well as the condensate temp leaving the air pump, we can try to determine if the problem is a too small condenser or an airleak somewhere/airpump that's too small.
I will tabulate and graph this a bit when i get an evening, but as Ive got the images with me finally and a moment while on holiday, please find attached below!
With engine driven pump, flow rate 6.5lmin/100rpm as above.
RPM Vac Cond Cool Boiler
235 17 60 40 175
220 20 48 35 190
205 20 40 35 180
235 18 55-60 40 170
170 20.6 28 30 180
- 20160312_221020.jpg (94.61 KiB) Viewed 6699 times
With electric pump flowing fixed 60/l min
- 20160312_221058.jpg (86.53 KiB) Viewed 6699 times
Thoughts welcomed!
Daniel
Re: Circulating water requirements
Posted: Fri Apr 01, 2016 6:55 am
by steamboatjack
I have been advising Dave Coates on this recently, I came up with a figure of 20 to 35 times the volume of feed water used to be supplied as cooling water with a surface condenser.
This is a ball park figure of course taken from an old text book about sea going ships, I would imagine with cool canal water the lower figure would suffice.
Regards
Jack
Re: Circulating water requirements
Posted: Wed Apr 13, 2016 7:23 pm
by Dhutch
steamboatjack wrote:I have been advising Dave Coates on this recently, I came up with a figure of 20 to 35 times the volume of feed water used to be supplied as cooling water with a surface condenser.
This is a ball park figure of course taken from an old text book about sea going ships, I would imagine with cool canal water the lower figure would suffice.
That's an interestint ball-park way of working it out.
Sounds like next step is to work out the real-world feedwater/evaporative rate of the boiler then.
As the system is condensing, allowing it to reach approximately steady-state and measuring the condensate outlet should do the trick, which can then be repeated at 'normal cruising' , when 'firing as hard as you can and using it all' and 'flat out, and dropping fast' engine speeds!
Boiler feed is engine driven, and could be calculated if I knew the cc/rev of the pump as well as the pulley ratio, but also has an auto by-pass which recirculates around 10% ish depending on demand.
Daniel
Re: Circulating water requirements
Posted: Wed Apr 13, 2016 7:23 pm
by Dhutch
What does anyone make of the above data? Does it suggest anything to anyone in terms of what could be root cause of the issues?
- How do the temps compare with your own findings Phil?
Daniel