POWER PLANT DESIGN PROBLEMS

Please answer the following questions and show solutions completely. Thanks!

$4.)$ A single acting $12-$cylinder, $4-$stroke cycle engine with a bore and stroke of $8$

inches x $10$ inches operates at $420rpm.$ The load on the brake arm at $2$ feet is $1\mathrm{.}5$

kip. Calculate the brake mean effective pressure in bar.

$5.)$ A four$-$stroke, $12-$cylinder Diesel engine has a cylinder diameter of $0\mathrm{.}85ft$ and

operates at $785rpm.$ It develops an indicated mean effective pressure of $185$ psi.

Compute the thermal efficiency in $\%$ if it has a brake specific fuel consumption of

$0\mathrm{.}485l\frac{b}{H}p-hr.$ The piston travels a distance of $1\mathrm{.}285ft.$ The Diesel fuel used has a

heating value of $38,500KJ$ per one liter and has a specific gravity of $0\mathrm{.}85.$ Use a

mechanical efficiency of $85\%$

$6.)$ A diesel power plant has a given data specifications $($Typical to each diesel

engine$)$: No of Diesel Engines $=3.$ No of cylinders per Diesel Engine $=12,$ Bore $x$

Stroke $=200mm240mm.$ No$.$ of strokes $=4.$ Fuel consumption $=0\mathrm{.}32k\frac{g}{K}w-hr$

per diesel engine, Heating Value $=132,000$ BTU$/$gallon$,$ Specific gravity $=0\mathrm{.}82.$

Engine speed $=320rpm.$ Indicated mean effective pressure $=13\mathrm{.}20$ bar. Calculate

the required volumetric flow rate of cooling water in gallons per minute if $32\%$ of

the heat supplied to three Diesel engines is being carried by a jacket water that

has an increase temperature of $132$ degrees $C.$