Chapter 7, Problem 7.68P

Three sub steps of a thermodynamic cycle are employed in order to change the state of a gas from 1 bar, 1.5 cubic meter and internal energy of 512 kJ. The processes are: 1st step: Compression at constant PV to a pressure of 2 bar and internal energy of 690 kJ. 2nd step: A process where work transferred is zero and heat transferred is - 150 kJ. 3rd step: A process where work transferred is -50 kJ. without KE and PE changes, determine: a. heat transferred during 1st step (kJ) b. heat transferred during 3rd step (kJ)

Steam at 44 bar and a dryness fraction, x = 0.9 is throttled to a pressure of 12 bar. Calculate thedifference in power output in kilowatts between the following two expansion processes:a) Steam at the initial pressure of 44 bar and x = 0.9 at State 1 is expanded in a turbine to State 3 at 0.12 bar.b) Steam at the reduced pressure of 12 bar after throttling at State 2 is expanded in another turbine to State 4 at the same exhaust pressure of 0.12 bar.The mass flow rate of steam is 8 kg/sec in both cases and the expansion in both turbines can be assumed to be reversible and adiabatic. Sketch both expansion processes on the same T-s diagram using the respective initial and final state points as described above.Explain the reason for the difference in power output.Calculate the mass flow rate of steam for the turbine operating at the throttled/reduced pressure to generate the same output as the turbine operating at the pressure before throttling.NOTE: You are required to number the state…

The following processes occur in a reversible thermodynamic cycle: 1-2: 0.2 kg heating at constant pressure 1.05 bar at specific volume 0.1 m/kg and work done -515 J. 2-3: Isothermal compression to 4.2 bar. 3-4: Expansion according to law pv1./= constant. 4-1: heating at constant volume back to the iniüal conditions. Calculate the work done for the constant volume heating process? Moving to another question will save this response. «< Questio acar A s P I R E

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A reversible heat pump cycle operates at steady state between hot and cold reservoirs at TH = 30°C and Tc 10°C, respectively. The rate of heat transfer at the high temperature is 10 kW. a. Determine the net power input, in kW. b. Determine the heat transfer rate from the cold reservoir at Tc, in kW. c. Determine the coefficient of performance of the cycle.

Steady-state operating data are shown in the figure for an open feedwater heater.Heat transfer from the feedwater heater to its surroundings occurs at an average outer surfacetemperature of 50°C at a rate of 100 kW. Ignore the effects of motion and gravity and let T 0 =25°C, p0 = 1 bar. Determine(a) the ratio of the incoming mass flow rates, ?̇# /?̇ $ .(b) the rate of exergy destruction, in kW.

Steam enters a counterflow heat exchanger operating at steady state at 0.04 MPa with a quality of 0.9 and exits at the same pressure as saturated liquid. The steam mass flow rate is 1.8 kg/min. A separate stream of air with a mass flow rate of 100 kg/min enters at 30°C and exits at 60°C. The ideal gas model with c, = 1.005 kJ/kg-K can be assumed for air. Kinetic and potential energy effects are negligible. Determine the temperature of the entering steam, in °C. For the overall heat exchanger as the control volume, what is the rate of heat transfer, in kW.

As shown in the figure below, two reversible cycles arranged in series each produce the same net work, Wcycle. The first cycle receives energy QH by heat transfer from a hot reservoir at TH-1000°R and rejects energy Q by heat transfer to a reservoir at an intermediate temperature, T. The second cycle receives energy Q by heat transfer from the reservoir at temperature T and rejects energy Qc by heat transfer to a reservoir at Te - 500°R. All energy transfers are positive in the directions of the arrows. Determine: Hot reservoir at TH lH R1 Reservoir Q at T 20 R2 lc Cold reservoir at Tc We cycle W Wcycle (a) the intermediate temperature T, in °R, and the thermal efficiency for each of the two power cycles. (b) the thermal efficiency of a single reversible power cycle operating between hot and cold reservoirs at 1000°R and 500°R, respectively. Also, determine the ratio of the network developed by the single cycle to the network developed by each of the two cycles, Wcycle-

Steam enters a counterflow heat exchanger operating at steady state at 0.05 MPa with a quality of 0.9 and exits at the same pressure as saturated liquid. The steam mass flow rate is 1.7 kg/min. A separate stream of air with a mass flow rate of 100 kg/min enters at 30°C and exits at 60°C. The ideal gas model with c, = 1.005 kJ/kg-K can be assumed for air. Kinetic and potential energy effects are negligible. Determine the temperature of the entering steam, in °C. For the overall heat exchanger as the control volume, what is the rate of heat transfer, in kW. Step 1 Your answer has been saved. See score details after the due date. Determine the temperature of the entering steam, in °C. T1 = 81.317 °C Attempts: 1 of 1 used Step 2 For the overallI heat exchanger as the control volume, what is the rate of heat transfer, in kW. kW Save for Later Attempts: 0 of 1 used Submit Answer