Chapter 8, Problem 8.34CU

Provide a complete and logical solution for the problem. If linear interpolation is required in the problem, tabulated values is considered as a solution. Also, provide T-S or P-V diagrams for each problem. For a Rankine Cycle, steam at 5.25 MPa, 435°C expands to 0.036 MPa. For 10 kg/s of steam, determine: a. Heat added b. Heat rejected c. Work of turbine d. Thermal Efficiency

Provide a complete and logical solution for the problem. If linear interpolation is required in the problem, tabulated values is considered as a solution. Also, provide T-S or P-V diagrams for each problem. For a Rankine Cycle, steam at 5.25 MPa, 435°C expands to 0.036 MPa. For 10 kg/s of steam, determine: a. Heat added b. Heat rejected c. Work of turbine d. Thermal Efficiency

2. A steam turbine installation takes steam at 70 bar, with 100°C of superheat, and expands to an exhaust pressure of 0.06 bar. If the efficiency ratio on the Rankine cycle is 0.75, determine the thermal efficiency of the installation and the specific steam consumption rate in kg/kWh. (0.29, 4.19)

Consider an ideal vapor compression system using R-134a. Its condensing pressure is 185 psia (sat. temp. 120 F) and evaporating pressure is 33 psia (sat. temp. 20 F). Using the attached P-h state diagram, answer the questions below. (You may want to have a ruler to help read the chart.) a) Show the ideal cycle. Label the states (1,2,3,4). b) Calculate the COP for this ideal cycle. c) Determine the refrigerating effect per refrigerant circulated [Btu/lbm], d) For ATsc = 10 F of subcooling, how much does it change the refrigeration effect [% change]. e) Determine the COP for part d. f) Determine the increase in COP for ATsh = 1 F of superheat. To answer this question, compare the cycle in part e that has 0 F superheat with a cycle that has 20 F of superheat and calculate 4COP/ATsh- %3D

7. Steam at 7.2 MPa, 600OC expands in a Rankine turbine to 0.45 MPa. For 180 kg/s of steam, determine the work, the thermal efficiency, and the steam rate (a) for the cycle, (b) for the turbine with the same specifications, the brake steam is 7.40 kg/kW-h and the driven electric generator has an efficiency of 91%. (c) Find eb, nb, WK, and quality or actual exhaust steam. Please answer letter c. Thanks

shown below is P-V diagram for a reversible cycle enclosed by 4 reversible process curves.  The curve 1-2 and the curve 3-4 are  reversible isothermal processes, and the curve 2-3 and the curve 1-4 are reversible adiabatic processes. If the cycle direction is counter clockwise, answer the question below. What is the cycle?____             A. Carnot cycle   B. ideal heat engine cycle   C. Carnot refrigeration cycle   D. Reversed refrigeration cycle

Q2. A gas turbine operates between pressures of 3 and 9 bar with a minimum and maximum cycle temperatures of 40 "C and 1500 °C. Both the compressor and turbine have isentropic efficiencies of 92%. The mass flow rate through the turbine is 0.4 kg/s. (a) 1. Sketch the ideal cycle on a T-s diagram including labels for: the different states (using the numbering in Figure Q2), heat and work transfers, as well as the pressure and temperature values given above. And add the curves and appropriate labels that show the effect of irreversible processes. ii. Starting from the relationship between pressure and volume for an ideal gas undergoing an isentropic process, and the ideal gas equation (both in Table 2), demonstrate the relationship between temperatures and pressures (Eq. Q2). T2 (Eq. Q2) Where: y is the ratio for specific heat, and 1 and 2 are the initial and final states. iii. Write down the equations for the isentropic efficiencies of the compressor and turbine as a function of the…

Draw a schematic diagramof each problem with labels of states of a substance;  For uniformity purposes, assign STATE 1 at the inlet of a high-pressure turbine. The states must be arranged in a chronological order; Plot each cycle in a t-s diagram with the states consistent to the states assignment in the schematic diagram; An ideal Rankine cycle with double reheat operates the boiler at 12MPa, the reheater at 5 MPa and 2.0 MPa, and the condenser at 0.01 MPa. The temperature at the boiler and reheater outlets are maintained at 400°C. a) Determine the total rate of heat transfer per unit mass in the reheaters, and b) the thermal efficiency of this cycle.

3. A medium size power station is used to produce 30 MW net power for a refinery. The station uses steam as the operating fluid and operates according to the Carnot cycle between the pressure limits of 0.4 bar and 35 bar. Steam enters the boiler as a saturated liquid and leaves it as a dry saturated vapour. (vii) Using the highest and lowest temperature values in the cycle, recalculate the efficiency of the cycle and show that it is equivalent to the result in part (vi). (viii) Calculate the thermal efficiency of the power station if the isentropic efficiency of the steam turbine is 94%. (ix) State main disadvantages of using the Carnot cycle as the basis for a power station. (x) State the name of the cycle that is used in practice in power stations, along with three key benefits over the Carnot cycle.