1. Air, which may be considered as a mixture of 79% N2 and 21% 02 by...

 

Transcribed Image Text:

1. Air, which may be considered as a mixture of 79% N2 and 21% 02 by mole numbers, is compressed by a steady-flow compressor. The inlet condition of the mixture ise 250 K and 1 MPa and the outlet condition is 390 K and 4 MPa. Determine the compressor power per mass flow rate by assuming the air (a) as an ideal gas (using Table A17) (b) as an ideal gas mixture (using Table A18 and 19) (c) as a real gas mixture (using Kay's Rule) (d) as a real gas (using Amagat's law) Problem 2 (35p) An air-conditioning system is to take in air at 1 atm, 39°C, and 50 percent relative humidity and deliver it at 17°C dry bulb and 10.8°C wet bulb. The air flows first over the T 39°c cooling coils, where it is cooled and dehumidified, and then over the 1=50% resistance heating wires, where it is heated to the desired temperature. Assuming that the condensate is removed from the cooling section at 5.3°C, determine (a) the dew point temperature of air before it enters the cooling section, (b) the dry bulb and dew point temperatures of air before it enters the heating section, (c) the amount of heat removed in the cooling section, and (d) the amount of heat transferred in the heating section, both in kJ/kg dry air. NOTE: Psychrometric chart can be used. Cooling | Heating section section T3 = 17°C T2 1 atm T3,wb =10.8 °C (3) 5.3°C Problem 3 (35p) The two air streams are mixed adiabatically in a continuous flow open system. One of the fluids enters the mixing section at 10°C temperature, 40% relative humidity and 15 m/ minute flow rate, and the other at 30°C temperature, 60% relative humidity and 30 m / minute flow rate. Mixing takes place at 100 kPa total pressure. Determine; a. Specific humidity, specific volume, enthalpy and mass flow rates of incoming streams, b. The mass flow rate of the mixture, b. The specific humidity, enthalpy, dry bulb temperature, relative humidity, volumetric flow rate of the mixture. Pg3= 0.1908*T(°C)-1.5173 NOTE: Do not use psychometric diagram, as the total pressure is 100 kPa. 1. Air, which may be considered as a mixture of 79% N2 and 21% 02 by mole numbers, is compressed by a steady-flow compressor. The inlet condition of the mixture ise 250 K and 1 MPa and the outlet condition is 390 K and 4 MPa. Determine the compressor power per mass flow rate by assuming the air (a) as an ideal gas (using Table A17) (b) as an ideal gas mixture (using Table A18 and 19) (c) as a real gas mixture (using Kay's Rule) (d) as a real gas (using Amagat's law) Problem 2 (35p) An air-conditioning system is to take in air at 1 atm, 39°C, and 50 percent relative humidity and deliver it at 17°C dry bulb and 10.8°C wet bulb. The air flows first over the T 39°c cooling coils, where it is cooled and dehumidified, and then over the 1=50% resistance heating wires, where it is heated to the desired temperature. Assuming that the condensate is removed from the cooling section at 5.3°C, determine (a) the dew point temperature of air before it enters the cooling section, (b) the dry bulb and dew point temperatures of air before it enters the heating section, (c) the amount of heat removed in the cooling section, and (d) the amount of heat transferred in the heating section, both in kJ/kg dry air. NOTE: Psychrometric chart can be used. Cooling | Heating section section T3 = 17°C T2 1 atm T3,wb =10.8 °C (3) 5.3°C Problem 3 (35p) The two air streams are mixed adiabatically in a continuous flow open system. One of the fluids enters the mixing section at 10°C temperature, 40% relative humidity and 15 m/ minute flow rate, and the other at 30°C temperature, 60% relative humidity and 30 m / minute flow rate. Mixing takes place at 100 kPa total pressure. Determine; a. Specific humidity, specific volume, enthalpy and mass flow rates of incoming streams, b. The mass flow rate of the mixture, b. The specific humidity, enthalpy, dry bulb temperature, relative humidity, volumetric flow rate of the mixture. Pg3= 0.1908*T(°C)-1.5173 NOTE: Do not use psychometric diagram, as the total pressure is 100 kPa.

Answer rating: 100% (QA)

3 At state 1 i calculation of specific humidity W1 0622 Pv Pt Pv1 and we have Relative humidity PvPvs 2 where Pvs 10 degC 001227 bar from steam table ... View the full answer