Chapter 7, Problem 7.28P

A divider separates 1 lb mass of carbon monoxide (CO) from a thermal reservoir at 150o F. the carbon monoxide, initially at 60o F  and 150 lbf/in2, expands isothermally to a final pressure of 10 lbf/in2 while receiving heat transfer through the divider from the reservoir. The carbon monoxide can be modeled as an ideal gas. (a) For the carbon monoxide as the system, evaluate the work and heat transfer, each in Btu and the amount of entropy produced, in Btu/oR. (b) Evaluate the entropy production, in Btu/oR, for an enlarged system that includesthe carbon monoxide and the divider, assuming the state of the divider remains unchanged. Compare with the entropy production of part (a) and comment on the difference.

A system executes a power cycle while receiving 1000 Btu by heat transfer at a temperature of 900°R and discharging 700 Btu by heat transfer at a temperature of 540°R. There are no other heat transfers. Determine the cycle thermal efficiency. Use the Clausius Inequality to determine  σ cycle  in Btu/°R. Determine if this cycle is internally reversible, irreversible, or impossible.

The exergy transfer to a steady-flow system is equal to the exergy transfer from it plus the exergy destruction within the system.

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 m3/kg and work done -515 J. 2-3: Isothermal compression to 4.2 bar. 3-4: Expansion according to law pv1.7= constant. 4-1: heating at constant volume back to the initial conditions.   Calculate the specific work done for process 1-2 in J/kg.

A silicon chip measuring 5 mm on a side and I mm in thickness is embedded in a ceramic substrate. At steady state, the chip has an electrical power input of 0.425 W. The top surface of the chip is exposed to a coolant whose temperature is 29°C. The heat transfer coefficient for convection between the chip and the coolant is 0.18 kw/m2 K. If heat transfer by conduction between the chip and the substrate is negligible, determine the surface temperature of the chip, in °R. Select one: O a. 714 O b. 353 O c. 396 O d. 635

An ice maker operating at steady state makes ice from liquid water at 32°F. Assume that 144 Btu/lb of energy must be removed by heat transfer to freeze water at 32°F and that the surroundings are at 79.0°F. The ice maker consumes 1.4 kW of power. Determine the maximum rate that ice can be produced, in Ib/h, the corresponding rate of heat rejection to the surroundings, in Btu/h, and the maximum coefficient of performance of the cycle.

Three pounds mass of water in a piston-cylinder assembly, initially a saturated liquid at 45 lb/in², undergoes a constant pressure, internally reversible expansion to x2 = 90%. For this reversible process, determine the work by integrating p dV and the heat transfer by integrating T dS, each in Btu. Step 1 * Your answer is incorrect. Determine the work by integrating p dV for this reversible process, in Btu. W12 = i 140.68 Btu

In a piston cylinder system, fluid at 0.7 bar occupying 0.05 m³ is compressed reversibly to a pressure of 9.8 bar and specific volume of 0.6 m3 m³/kg according to the law pv" = c. The fluid then expands reversibly according to the law pv² = c to 2.1 bar. A reversible cooling at constant volume then restores the fluid back to initial state. Calculate the value of n in the process. Calculate to 3 d.p.

In a piston cylinder system, a fluid at 0.8 bar occupying 0.07 m³ is compressed reversibly to a pressure of 10.2 bar and specific volume of 0.6 m³/kg according to the law p = c. The fluid then expands reversibly according to the law pv² = c to 1.1 bar. A reversible cooling at constant volume then restores the fluid back to initial state. Calculate the net work for the process in Joules. To 3 d.p. and insert the unit symbol joules.