Chapter 7, Problem 7.6E

A gas within a piston-cylinder assembly executes a Carnot power cycle during which the isothermal expansion occurs at TH = 500 K and the isothermal compression occurs at Tc = 290 K. Determine: (a) the thermal efficiency. (b) the percent change in thermal efficiency if TH increases by 15% while Tc remains the same. (c) the percent change in thermal efficiency if Tc decreases by 15% while TH remains the same. (d) the percent change in thermal efficiency if TH increases by 15% and Tc decreases by 15%. Part A Determine the thermal efficiency. na = Save for Later % Attempts: 0 of 5 used Part B The parts of this question must be completed in order. This part will be available when you complete the part above. Part C The parts of this question must be completed in order. This part will be available when you complete the part above. Part D The parts of this question must be completed in order. This part will be available when you complete the part above. Submit Answer

The Dipping Bird Machine experiment:explain the dipping bird machine  motion in the context of a thermodynamic cycle,and explain the sources of irreversibility that prevent the machine from becoming a perpetual machine.

A system undergoes a power cycle while receiving 1450 kJ by heat transfer from a thermal reservoir at a the temperature of 780 K and discharging 560 kJ by heat transfer to a thermal reservoir at (a) 250 K, (b) 380 K, (c) 460 K.  For each case, determine whether the cycle operates irreversibly, operates reversibly, or is impossible.

Select the Kelvin-Plank statement of the second law of Thermodynamics___________   A. It is impossible to construct a device that operates in a cycle and produces no effect other than the transfer of heat from a lower-temperature body to a higher-temperature body.     B. It is impossible for any device that operates on a cycle to receive heat form a single reservoir and produce a net amount of work.

Problem 1 Calculate the thermal efficiency or coefficient of performance of the following cycles, and determine if the cycles are reversible, irreversible, or impossible. (a) A steam power cycle that receives thermal energy at a rate of 800 kW from a thermal source at 550°C and rejects thermal energy at a rate of 300 kW to a thermal sink at 50°C. (b) A heat pump that needs 10 kJ work input to deliver 120 kJ of thermal energy to a room at 27°C. The heat pump interacts with a low temperature reservoir at 5°C.

A system executes a power cycle while receiving 1000 Btu by heat transfer at a temperature of 900oR and discharging 600 Btu by heat transfer at a temperature of 540oR. There are no other heat transfers.Determine the cycle thermal efficiency.  Use the Clausius Inequality to determine σcycle, in Btu/oR. Determine if this cycle is internally reversible, irreversible, or impossible.

.......A gas turbine power plant is operated between 1.5 bar and 15 bar with minimum and maximum cycle temperatures of 25 C and 1420 C, respectively. Neglect the mass of the fuel.   Determine the following: Work of the compressor in kJ/kg (2 decimal places) = Work of the gas turbine in kJ/kg (2 decimal places) = Heat added in the combustion chamber in kJ/kg (2 decimal places) = Net Work in kJ/kg (2 decimal places) = Thermal Efficiency in % (1 decimal place only) =

Two reversible cycles operate between hot and cold reservoirs at temperatures TH and TC, respectively. (a)If one is a power cycle and the other is a refrigeration cycle, what is the relation between the coefficient of performance of the refrigeration cycle and the thermal efficiency of the power cycle? (b)If one is a refrigeration cycle and the other is a heat pump cycle, what is the relation between their coefficients of performance?

The thermal efficiency of a reversible power cycle operating between hot and cold reservoirs is 80%. Evaluate the coefficient of performance of: (a) a reversible refrigeration cycle operating between the same two reservoirs. (b) a reversible heat pump cycle operating between the same two reservoirs.