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3.6.2 Double Interpolation
Double interpolation must be used when two of the properties (eg. Temperature and pressure) are not
tabulated in the Steam Tables.
EXAMPLES 7
1. Determine the specific enthalpy of superheated steam at 25 bar and 320 C. (h =3057 kJ/kg)
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2. 0.9 m of dry saturated steam at 225 kN/m is contained in a rigid cylinder. If it is cooled at constant volume
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3
process until the pressure drops to180 kN/m , determine the following:
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a) mass of steam in the cylinder (m =1.134 kg)
b) dryness fraction at the final state (x =0.81) Sketch the process in the form of a P-v diagram
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