Problem Set 5. Due Oct7. 5-1 Superheated steam can be cooled by injecting liquid water into...

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Problem Set 5. Due Oct7. 5-1 Superheated steam can be cooled by injecting liquid water into it, and this process is termed "desuperheating." A flow of 0.5 kg/s superheated steam at 5 MPa, 400°C and a flow of liquid water at 5 MPa, 40°C are mixed. If saturated water vapor at 4.5 MPa is desired, what is the required flow rate of liquid water (kg/s)? 5-2 An air compressor takes in air at 100kPa, 17°C and delivers it at 1 MPa, 600K to a constant pressure cooler which it exits at 300K. Find the work performed and heat transfer, both (kJ/kg). Use variable specific heats (Table A-17). 5-3 Helium (initially at 160°F and 30 psia) is slowly withdrawn from a well-insulated rigid tank of volume 7 ft² until the pressure reaches 18 psia. An electrical resistor inside the tank maintains the temperature at 160°F. Determine the mass of helium withdrawn (lbm) and the heat input to the resistor (Btu). Note that the problem can be worked without explicitly using values for enthalpy and internal energy. 5-4 Saturated vapor steam at 4 MPa is contained in a 2 m³ insulated vessel. A valve on the top of the tank is opened, allowing steam to escape. If any liquid is formed, it will drop to the bottom of the tank, so that saturated vapor only will escape from the top of the tank. Calculate the total mass that has escaped when the tank pressure reaches 1 MPa. Note that value of the saturated vapor enthalpy leaving the tank changes as the pressure drops. However, the values of hg at 4 MPa and 1 MPa are not grossly different, so the average of the two can be used for the escaping stream term in the energy balance, if needed. Problem Set 5. Due Oct7. 5-1 Superheated steam can be cooled by injecting liquid water into it, and this process is termed "desuperheating." A flow of 0.5 kg/s superheated steam at 5 MPa, 400°C and a flow of liquid water at 5 MPa, 40°C are mixed. If saturated water vapor at 4.5 MPa is desired, what is the required flow rate of liquid water (kg/s)? 5-2 An air compressor takes in air at 100kPa, 17°C and delivers it at 1 MPa, 600K to a constant pressure cooler which it exits at 300K. Find the work performed and heat transfer, both (kJ/kg). Use variable specific heats (Table A-17). 5-3 Helium (initially at 160°F and 30 psia) is slowly withdrawn from a well-insulated rigid tank of volume 7 ft² until the pressure reaches 18 psia. An electrical resistor inside the tank maintains the temperature at 160°F. Determine the mass of helium withdrawn (lbm) and the heat input to the resistor (Btu). Note that the problem can be worked without explicitly using values for enthalpy and internal energy. 5-4 Saturated vapor steam at 4 MPa is contained in a 2 m³ insulated vessel. A valve on the top of the tank is opened, allowing steam to escape. If any liquid is formed, it will drop to the bottom of the tank, so that saturated vapor only will escape from the top of the tank. Calculate the total mass that has escaped when the tank pressure reaches 1 MPa. Note that value of the saturated vapor enthalpy leaving the tank changes as the pressure drops. However, the values of hg at 4 MPa and 1 MPa are not grossly different, so the average of the two can be used for the escaping stream term in the energy balance, if needed.

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Answer then 2 TA Date Answer qu flow 05 kg see Dression Superheated steam 5 MPg p Saturated 2 fl... View the full answer