Thermo - Steam properties - HN

The saturation temperature of water

• is 99.6^oC

• is the constant temperature during evaporation

• is higher for saturated steam than for wet steam

• all of the above

The density of steam is

• dependent on mass

• 1000 kg/m³

• dependent on pressure and temperature

• calculated from pV=mRT

The enthalpy needed to evaporate 1 kg of water at 2 bar is

• 2202 kJ

• 2707 kJ/kg

• 2202 kJ/kg

• 2530 kJ

Wet steam has enthalpy

• higher than saturated water

• lower than dry steam

• dependent on dryness fraction

• all of the above

Superheated steam has internal energy

• higher than wet steam

• decreasing with increasing temperature

• increasing with increasing pressure

• all of the above

Steam at 1 bar and 110^oC is

• saturated steam

• wet steam

• superheated steam

• there is not enough data to judge

If saturated water and dry steam enthalpy at certain conditions is 1185 and 2790 kJ/kg respectively, then 50% wet steam enthalpy is:

• 1205 kJ/kg

• 802.5 kJ/kg

• 1988 kJ/kg

• 3125 kJ/kg

Dry steam has a density of 8.084 kg/m³, what is its pressure?

• 2 bar

• 16 bar

• 16 N/m²

• not enough data is provided

Wet steam is coming out of a turbine at 139^oC. Which of the values below can be its internal energy?

• 1100 kJ/kg

• 2549 kJ/kg

• 584 kJ/kg

• 3127 kJ/kg

Superheated steam from a boiler is known to have enthalpy of 3070x10³ J/kg at 300^oC, what is its pressure?

• 30 bar

• 3 MPa

• not enough data is given

• 300 kPa