A Carnot heat engine produces 1 MW by transferring energy between two reservoirs at 100 °C and 5 °C. Calculate the rate of heat transfer from the high-temperature reservoir and the rate of heat transfer to the low-temperature reservoir.
An industrial plant wants to use hot groundwater from a hot spring to power a heat engine. The maximum temperature of the ground water is 200 °F, and the average atmospheric temperature is 60 °F. Assume that a supply of water at 1.0 lbm/sec is available. What is the maximum power that can be generated?
An industrial proposer claims that he can extract 50 kw power by drawing 3000 kJ of heat per minute from a high-temperature reservoir at 950 °C and dumping heat to a reservoir at 25 °C. Is this device feasible?
A Carnot engine rejects 100 MJ of heat every hour to a low-temperature reservoir at 5 °C. If the high-temperature reservoir provides 50 kW of heat, what is the power produced and the temperature of the high-temperature reservoir?
Gas is stored in a rigid container at 7 °C. The volume of the container is 2 cubic meters. The initial gage pressure is 0. The gas is heated and reaches a gage pressure of 0.8 MPa. Atmospheric pressure is 100 kPa. What is the entropy change of the gas if the gas is (a) helium, (b) hydrogen, (c) nitrogen, (d) air, and (e) carbon dioxide?
The temperature of a gas changes from 17 °C to 487 °C, while the pressure remains constant at 0.2 MPa. Compute the heat transfer and entropy change if the gas is (a) air, (b) helium, or (c) carbon dioxide.
A piston cylinder arrangement is used to compress 0.1 kg of air isontropically from initial conditions of 200 kPa and 17 °C to 3.0 MPa. Calculate the work necessary (a) assuming a constant specific heat and (b) the gas table.
Three kilogram of steam initially at a quality of 40% and a pressure of 4 MPa is expanded in a cylinder at constant temperature until the pressure is halved. Determine the entropy change and the heat transfer.
A Carnot engine using steam has a pressure of 50 kPa and a quality of 30% at the beginning of the adiabatic compression process. If the thermal efficiency is 35% and the adiabatic expansion process begins with a saturated vapor, determine the heat added.
A turbine accepts steam at 2.0 MPa and 627 °C and discharge at 20 kPa. Every second 4 kg of superheated steam passes through the turbine. Calculate the maximum power rating of the turbine.
A Carnot engine operates at 6000 cycles per minute with 0.5 lbm of steam per the diagram below (Fig. 7.9
). The quality of state 1 is 34.52%.
What is the power output?
What is the quality at state 4?
A 500 kW turbine works off steam entering at 627 °C and produces saturated steam at 50 kPa. What is the minimum mass flux of steam required?