Thermodynamics?

mink_man

Have an exam in thermodynamics in a while, wicked bad lecturer so wondering is there any website with worked examples on thermodynamics?

Darren1o1

mink_man wrote: »

Have an exam in thermodynamics in a while, wicked bad lecturer so wondering is there any website with worked examples on thermodynamics?

What level/topics? Do you have a module descriptor?

mink_man

there's 2 tutorial sheets that are in pdf and I can't load up so here are the ones I can.


Tutorial Set 3- Thermodynamics


Q1. A rigid tank contains 50kg of saturated liquid water at 750C. Determine the pressure volume and enthalpy of the liquid inside the tank.


Q2. A mass of 1000kg of saturated liquid water is completely vaporized in a isobaric (100kPa) heat addition process.
o Find the volume change between states
o The amount of energy required to perform this process.


Q3. A rigid tank contains 100kg of a liquid vapour mixture of water at 600C, if 8kg is in liquid form (i.e. water).
o Determine the pressure inside the tank as well as the tanks volume
o Determine the energy available to the substance inside the tank.

Q4. An 800L vessel contains 200kg of a liquid-vapor mixture (i.e. water) at 200kPa.
o Determine the temperature of the mixture
o The quality of the mixture
o The enthalpy of the mixture
o The volume occupied by the vapour and fluid.


Tutorial Set 4- Thermodynamics


Q1. Superheated steam enters a turbine under a pressure of 800kPa at a temperature of 600oC at a rate of 500kg/min with a velocity of 75m/s. If the steam exits the turbine as a wet vapour (i.e. liquid vapour mixture) at a pressure of 200kPa with a quality of 95%, determine
o The area of the inlet of the turbine
o Determine the heat produced/dissipated by the turbine if 400kW of mechanical work are produced.
o Comment on the direction of this heat

Q2. An industrial type welder takes in air from a high pressure supply at 20MPa at a temperature of 25oC. The air is expanded inside the welder to drive a blower which is rated at 3.5kW. If 20% of the total air intake leaves via the first exhaust at a temperature of 20oC at a pressure of 10MPa and the rest is exhausted to the atmospheric pressure. If air enters the system at a rate of 0.25kg/s, find
o The mass flow rate of air at each exit exhaust
o The temperature of air at the 2nd exhaust
o The volumetric flow rate of air at each exhaust
[Note: Assume that the system is adiabatic]

Q3. Air at a temperature of 500C and at a pressure of 100kPa enters a wide angle diffuser with a velocity of 150m/s. The inlet area of the diffuser is 0.4m2 and if the exit area is much larger, find
o The mass flow rate of air
o The temperature of air at the exit of the diffuser

Q4. A hot-water stream at 800C enters into a mixing chamber with a mass flow rate of 0.5kg/s where it is mixed with a cold water stream at 20oC. If its is desired that the mixture leaves the chamber at 45oC. Determine the mass flow rate of the cold-water stream. Assume that all the streams are at a pressure of 250kPa.

Q5. An adiabatic compressor is powered by a direct-coupled adiabatic steam turbine, which is also driving an electrical generator as depicted.


Steam enters the turbine at 12.5MPa and 5000C at a rate of 25kg/s an exits at 10kpa with a quality of 0.92. Air at 98kPa and at a temperature of 295K enters the compressor at a rate of 10kg/s and exits at 1MPa and 620K. Determine
o The gross power generated by the turbine.
o The power consumed by the generator.
o The power delivered to the electrical generator.

Q6. An insulated air reservoir tank takes in air from an industrial process at 1500C and 10Atm. The reservoir tank contains a heater and a pressure relief valve to maintain the tank pressure at 9Atm if that pressure is ever reached. During one operation 7kg of air enter the tank and 1.5kg of air leaves through the pressure relief valve. The exiting air has an average temp of 750C. During the operation 100kJ of energy is supplied to the heater. Prior to the start of the operation the tank contains 0.5kg of air at 250C.
o Find the mass of air in the tank after the operation is complete.
o The final temperature of air inside the tank.
o The volume of the tank.
o The change in internal energy of the tank.

Q7. Superheated steam enters an adiabatic turbine steadily at 3MPa and 4000c and leaves at 50KPa and 1000c. If the Power output by the turbine is 2MW.
o Determine the mass flow rate through the turbine.
o The efficiency of the turbine.

The first 2 tutorial sheets are to do with PV=MRT etc.

hughie1989

I'm not sure about websites but I would recommend a book called 'Thermodynamics: An Engineering Approach'. Authors are Cengel and Boles. It is excellent and definitely worth the buy if your library doesn't have it! Best of luck!

mink_man

hughie1989 wrote: »

I'm not sure about websites but I would recommend a book called 'Thermodynamics: An Engineering Approach'. Authors are Cengel and Boles. It is excellent and definitely worth the buy if your library doesn't have it! Best of luck!

good man Hughie