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Steam at 120 bar has a specific volume of 0.01721 m3/kg, find the temperature, enthalpy and the internal energy. |
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Answer» Pressure of steam, p = 120 bar Specific volume, v = 0.01721 m3/kg (i) Temperature : First it is necessary to decide whether the steam is wet, dry saturated or superheated. At 120 bar, vg = 0.0143 m3/kg, which is less than the actual specific volume of 0.01721 m3/kg, and hence the steam is superheated. From the superheat tables at 120 bar, the specific volume is 0.01721 m3/kg at a temperature of 350°C. (ii) Enthalpy : From the steam tables the specific enthalpy at 120 bar, 350°C, h = 2847.7 kJ/kg. (iii) Internal energy : To find internal energy, using the equation, u = h – pv = 2847.7 – \(\cfrac{120\times10^5\times0.01721}{10^3}\) = 2641.18 kJ/kg. |
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