The bores of a compound steam engines cylinders are 300 mm

and 600 mm while the common stroke is 400 mm. The supply steam is at a pressure

of 11 bar and cut-off is at of stroke in the H.P. cylinder. The

back pressure in the L.P. cylinder is 0.32 bar. The details of the indicator

card are: for the H.P. cylinder, the diagram area is 12.5 cm2 and the spring

scale is 2.7 bar/cm; for the L.P. cylinder, the diagram area is 11.4 cm2 and

the spring scale is 0.8 bar/cm. The length of both diagrams is 7.5 cm.

Determine:

(a) The theoretical and actual mean effective pressures

referred

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The bores of a compound steam engines cylinders are 300 mm

and 600 mm while the common stroke is 400 mm. The supply steam is at a pressure

of 11 bar and cut-off is at of stroke in the H.P. cylinder. The

back pressure in the L.P. cylinder is 0.32 bar. The details of the indicator

card are: for the H.P. cylinder, the diagram area is 12.5 cm2 and the spring

scale is 2.7 bar/cm; for the L.P. cylinder, the diagram area is 11.4 cm2 and

the spring scale is 0.8 bar/cm. The length of both diagrams is 7.5 cm.

Determine:

(a) The theoretical and actual mean effective pressures

referred to the L.P. cylinder.

(b) The overall diagram factor and indicated power if the

engine runs at 162 r.p.m.

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