Hello everyone since my last post I've been working on boiler/burner calculations based on the calculations I made for a 1.5"x2" cylinder.
From [
www.sizes.com]
I have read that basically a hundred years the ASME set the standard that 34,478.8 BTU/hr is equal to 1 Boiler horsepower (BHP) that is the amount of energy required to turn 34.8 pounds of water into steam in one hour and power an steam engine. This standard was created so that owners could determine whether the size of their boilers was adequate, to large, or to small to power their engines.
Since the engine I plan to locate and use for my steam bike will produce about .5 HP and I want to have some reserve hp for going up hills I will plan on a of 2/3 or .67 BHP, which is around 22,000 BTU/hr.
For the burner like I said in an earlier post i plan to use a propane stove for the burner so I have to find a 22,000 BTU/hr propane stove, which shouldn't be to difficult. Then at this point I'll use the specs for it to help design a boiler.
After calculating the BHP of the boiler I located calculations for the required water storage tank size, the flow rate of water that needs to be pumped to run the boiler per hour at .67 BHP, and also determined the pressure the water pump will be required to pump to put water in the boiler on the website
[
www.mckenziecorp.com]
The equation for the water storage tank size is:
BHP X 34.5 ÷ 8.337 lbs ÷ 60 min. X 10 X 1.5 = useable capacity in gallons.
BHP= Boiler Horsepower
34.5= lbs of steam (water)/hr to make 1 BHP
8.337= the weight of 1 lb of water
60 min.= The time in 1 hour
10= The amount of time on average the pumps will run per hour
(in my case because I will build a flash tube boiler the pumps will run almost constantly so I ignore this and the 60)
1.5= is a safety factor to make sure there is additional water available.
GMP= Gallons Per Minute
For my case:
(2/3) X 34.5 ÷ 8.337 X 1.5 = 4.13 Gallons, which is basically a 4 gallon tank
The equation for the rate of water that needs to be pumped in is:
BHP X 34.5 ÷ 8.337 ÷ 60 X 1.5 = GPM
For my case:
(2/3) X 34.5 ÷ 8.337 ÷ 60 X 1.5 = .0689 GPM or 4.13 GPH (Gallons Per Hour)
The equation for the pressure the pump should be pumping at is:
safety valve psi X 1.03 + 5 lb drop = psi of pump
1.03= 3% increase over safety valve pressure
5= estimated drop of pressure between pump and boiler
For my case:
250 X 1.03 + 5 = ~260 psi
260 psi will be the correct pressure for the pumps.
That's all for now.
Edited 2 time(s). Last edit at 07/28/2009 02:33AM by Stanleyguy101.