459
OF ENGINEERING FORM ULÆ.
Relative Heating Power of Fuel. (Fritz)
Fuel. Theoretical. Lbs. of Water evaporated by 1 lb. of Fuel.
In Steam Boilers. In Oiæn Boilers.
Anthracite • .. Coal Charcoal .. .. Coke Brown coal .. Peat Wood .. .. Straw ,. ,. Gas reduced to ) lbs. coal.. J 12-46 11-51 10-77 9-00 to 10-8 7-7 5-5 „ 7-4 4-3 „ 5’6 3-0 5-2 to 8 6 „ 6’75 5 „8 2-2 „ 5'5 2-5 „ 4-5 2-5 „ 3-75 1-86 „ 1-92 4 „6 5-2 3-7 1-5 to 2-3 1-7 „ 2-3 1-85 „ 2-1
In heating boilers, on an average only 47 per cent. <rf the
theoretical heating power of fuel is utilized, the remainder
being lost through imperfect combustion, radiation, and other
causes.
Relation' between Effective and Theoretical Work
ok Fuel in Different Motobs.
Small hiuli-pressure engine without expansion 1-8
Air engine (Erricson) .. .. ................1’8
„ (Leaubvreau) ....................1'8
„ (Lehman).........................1’9
Gas engine (Lenoir) ................2-0
„ ' (Hugon) ....................2-0
Portable sWni engine........................2-8
High-pressure steam engine with expansion .. 3’0
Air engine (Leawitt)........................3’5
„ (Belou) .........................4-1
Condensing engine with expansion............4-5
Gas engine (Otto and Langen)_____________ 5'0
Petroleum engine............................8-4
Large steam engine, best make...............9-0
The cost of fuel in gas engines exceeds that for steam
engines from 2| to 5 times; so that notwithstanding the
many advantages they cannot compete with steam*engines.