Chapter 7, Problem 7.90P

Determine the specific exergy of saturated water vapor at 137 °C, where To = 313K, Po = 101.3kPa. Assume the velocity and elevation is zero with reference to the environment. You must use following tables to solve this problem. (answer to 2 decimal) Saturated water temperature table Sat Liq. Temp., Sat Liq. Sat Liq. Sat Liq. vf uf hf sf °C m3/kg kJ/kg kJ/kg kJ/kg.K 30 0.001004 125.73 125.74 0.4368 35 0.001006 146.63 146.64 0.5051 40 0.001008 167.53 167.53 0.5724 45 0.00101 188.43 188.44 0.6386 Saturated water temperature table Temp., Sat. Vap. Sat. Vap. Sat. Vap. Sat. Vap. hg kJ/kg vg ug sg °C m3/kg kJ/kg kJ/kg.K 125 0.7508 2534.5 2713.5 7.0745 126 0.7358 2535.5 2714.8 7.0649 127 0.7208 2536.5 2716.1 7.0553 128 0.7058 2537.5 2717.4 7.0457 129 0.6908 2538.5 2718.7 7.0361 130 0.6758 2539.5 2720.0 7.0265 131 0.6608 2540.5 2721.4 7.0169 132 0.6458 2541.4 2722.7 7.0073 133 0.6308 2542.4 2724.0 6.9977 134 0.6158 2543.4 2725.3 6.9881 6.9785 135 0.6008 2544.4 2726.6 136 0.5858 2545.4 2727.9…

7.36 At steady state, hot gaseous products of combustion from a gas turbine cool from 3000°F to 250°F as they flow through a pipe. Owing to negligible fluid friction, the flow occurs at nearly constant pressure. Applying the ideal gas model with ₂ = 0.3 Btu/lb/ºR, determine the exergy transfer accompanying heat transfer from the gas, in Btu per lb of gas flowing. Let T. = 80°F and ignore the effects of motion and gravity. -568.43

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 30oC and exits at 60oC. The ideal gas model with cp = 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 oC.For the overall heat exchanger as the control volume, what is the rate of heat transfer, in kW.

7.29 A gearbox operating at steady state receives 4 hp along the input shaft and delivers 3 hp along the output shaft. The outer surface of the gearbox is at 130°F. For the gearbox, (a) determine, in Btu/s, the rate of heat transfer and (b) perform a full exergy accounting, in Btu/s, of the input power. Let To 70°F.

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

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 1.6 kg/min. A separate stream of air with a mass flow rate of 100 kg/min enters at 30oC and exits at 60oC. The ideal gas model with cp = 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 oC.For the overall heat exchanger as the control volume, what is the rate of heat transfer, in kW.

If the specific exergy of a gas in a cylinder of an internal combustion engine modeled as air behaving like an ideal gas is 368.91 kJ / kg and the cylinder contains 2450 cm2 of gaseous combustion products. Åt what elevation in meters 3-kg mass does it have to be lifted from zero elevation with respect to the reference environment so that its exergy equals the exergy of the cylinder? Assume gravity as g = 9.81 m /s^2 NOTE: The density of dry air at a pressure of 7 bar and a temperature of 867 ° C is 2.1388 kg / m^3.

Thermodynamics, please show all work. Step 1 and 2.

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