Page 231 - Handbook of Energy Engineering Calculations

Select a lube-oil cooler suitable for a heat-transfer load of 330,000 Btu/h
(96.7 kW) at the prevailing cooling-water temperature difference, which is
usually assumed to be 10°F (5.6°C). See previous calculation procedures for
the steps in selecting a liquid cooler.

3. Determine the lube-oil consumption rate

The lube-oil consumption rate is normally expressed in terms of bhp · h/gal.
Thus, if this engine operates for 24 hours and consumes 2 gal (7.6 L) of oil,
its lube-oil consumption rate = (24 h)(500 bhp)/2 gal = 6000 bhp · h/gal
(1183 kWh/L).

Related Calculations. Use this procedure for any type of internal-combustion
engine using any fuel.

DETERMINING SOLIDS INTAKE OF I-C ENGINES

What weight of solids annually enters the cylinders of a 1000-hp (746-kW)
internal-combustion engine if the engine operates 24 h/day, 300 days/year in
3
an area having an average dust concentration of 1.6 gr per 1000 ft of air
3
3
(28.3 m )? The engine air rate (displacement) is 3.5 ft /(min · bhp) (0.13
3
m /kW). What would the dust load be reduced to if an air filter fitted to the
engine removed 80 percent of the dust from the air?

Calculation Procedure:

1. Compute the quantity of air entering the engine
3
Since the engine is rated at 1000 hp (746 kW) and uses 3.5 ft /(min · bhp)
3
[0.133 m /(min · kW)], the quantity of air used by the engine each minute is
3
3
3
(1000 hp)[3.5 ft /(min · hp)] = 3500 ft /min (99.1 m /min).
2. Compute the quantity of dust entering the engine
3
3
Each 1000 ft (28.3 m ) of air entering the engine contains 1.6 gr (103.7 mg)
of dust. Thus, during every minute of engine operation, the quantity of dust
entering the engine is (3500/1000)(0.6) = 5.6 gr (362.8 mg). The hourly dust
intake = (60 min/h)(5.6 gr/min) = 336 gr/h (21,772 mg/h).