Chapter 6, Problem 6.82P

Air expands adiabatically in a piston–cylinder assembly from an initial state where p1 = 100 lbf/in.2, v1 = 3.704 ft3/lb, and T1 = 1000 °R, to a final state where p2 = 20 lbf/in.2 The process is polytropic with n = 1.4. The change in specific internal energy, in Btu/lb, can be expressed in terms of temperature change as Δu=(0.171)(T2 - T1).Determine the final temperature, in °R.Kinetic and potential energy effects can be neglected.

Steam enters a turbine operating at steady state at 440°C and 30 bar and leaves as a saturated vapor at 0.08 bar. The turbine develops 9000 kW, and heat transfer from the turbine to the surroundings occurs at a rate of 590 kW. Neglect kinetic and potential energy changes from inlet to exit. a. Determine the exit temperature, in °C. b. Determine the volumetric flow rate of the steam at the inlet, in m³/s. T₁-440°C P₁=30 bar Qout 590 kW 2 X₂ 100%(sat.vapor) P₂=0.08 bar W turbine = 9000 kW

T-3

Steam enters a turbine operating at steady state at 800°F and 450 Ibf/in2 and leaves as a saturated vapor at 0.8 Ibf/in2. The turbine develops 12,000 hp, and heat transfer from the turbine to the surroundings occurs at a rate of 2 x 106 Btu/h. Neglect kinetic and potential energy changes from inlet to exit. Determine the exit temperature, in °F, and the volumetric flow rate of the steam at the inlet, in ft³/s.

A spring-conditioned cylinder-piston device contains 0.25kg of air and operates under the following thermodynamic cycle:1 -> 2: In state 1, P_1 = 200kPa and V_1 = 0.25m ^ 3. The compressed spring is released and the air is compressed, until the spring no longer stores energy and the piston simply rests on the stops: P_2 = 300kPa and V_2 = 0.10m ^ 3.2 -> 3 After compression the heat is removed and the pressure drops to 100kPa in state 3.3 -> 1: Heat is added, the spring is compressed, and the air expands to state 1. a) Make a diagram of the process and trajectories.b) Determine the air temperature in the 3 states.c) Calculate the work from state 1 to 2.d) Calculate the work from state 3 to 1.e) Calculate the total work of the cycle and who performs it.

Steam enters a turbine operating at steady state at 750°F and 450 lbf/in² and leaves as a saturated vapor at 0.8 lbf/in². The turbine develops 12,000 hp, and heat transfer from the turbine to the surroundings occurs at a rate of 2 x 106 Btu/h. Neglect kinetic and potential energy changes from inlet to exit. Determine the exit temperature, in °F, and the volumetric flow rate of the steam at the inlet, in ft³/s. Step 1 Determine the exit temperature, in °F. T₂ = i °F.

Steam enters a turbine operating at steady state at 750°F and 450 lbf/in² and leaves as a saturated vapor at 0.8 lbf/in². The turbine develops 12,000 hp, and heat transfer from the turbine to the surroundings occurs at a rate of 2 x 106 Btu/h. Neglect kinetic and potential energy changes from inlet to exit. Determine the exit temperature, in °F, and the volumetric flow rate of the steam at the inlet, in ft3/s. Step 1 Your answer is correct. Determine the exit temperature, in °F. T2 = 94.3 Hint Step 2 °F. Determine the volumetric flow rate of the steam at the inlet, in ft³/s. (AV) 1 = i ft³/s Attempts: 1 of 4 used

Air within a piston-cylinder assembly, initially at 50 lbf/ in.², 510°R, and a volume of 6 ft³, is compressed isentropically to a final volume of 3 ft³. Assuming the ideal gas model with k = 1.4 for the air, determine the: (a) mass, in lb. (b) final pressure, in lbf/in.² (c) final temperature, in °R. (d) work, in Btu.

Refrigerant 134a at p₁ = 30 lbf/in², T₁ = 40°F enters a compressor operating at steady state with a mass flow rate of 350 lb/h and exits as saturated vapor at p2 = 160 lbf/in². Heat transfer occurs from the compressor to its surroundings, which are at To = 40°F. Changes in kinetic and potential energy can be ignored. The power input to the compressor is 3.5 hp. Determine the heat transfer rate for the compressor, in Btu/hr, and the entropy production rate for the compressor, in Btu/hr.°R.