1. A source of heat at 1000 K transfers 1000 kW of power to a power generation device, while producing 300 kW of useful work. Determine: a. The rate of exergy destruction in this process if the environment is at 300K. b. The second law efficiency of the system.

A heat engine produces 50 kW of power while consuming 50 kW of heat from a source at 1390 K, 70 kW of heat from a source at 1690 K , and rejecting the waste heat to the atmosphere at 300 K. Part A Determine the reversible power. Express your answer to three significant figures and include appropriate units. ? Value Units Submit Request Answer Part B Determine the rate of exergy destruction (I) in the engine's universe. Express your answer to three significant figures and include appropriate units. HẢ Value Units

A steady-state system for producing power consist of a pump, heat exchanger and a turbine. Water at 1.0 bar and 20°C (state 1) enters the adiabatic pump and leaves at 10 bar (state 2). The pump draws 110 kW of power, and the mass flow rate of water is 45 kg/s. The water leaving the pump enters a heat exchanger and heated at constant pressure to 400°C (state 3) using exhaust gases (Cp of gases = 1.1 kJ/kgK) that enters at 500°C and exits at 182°C. The steam is adiabatically expanded in a turbine having an isentropic efficiency of 0.71. The turbine exhausts (state 4) to the surroundings at 1.0 bar. What is thermal efficiency of this power production process? If the pump and turbine are reversible, would the efficiency of this system equal the maximum possible efficiency? (Answer Yes or NO and provide a short explanation.)

Between a heat source at temperature T and a low-temperature heat well at 280 K power cycle is working. In steady state, the cycle produces 50 kW of work, while the heat well is 1000 kl/min. heats up. Determine the minimum theoretical value for T in K (Kelvin).

thermodynamics    A piston–cylinder device initially contains 2 L of air at 100 kPa and 25°C. The air is now compressed to a state of 620kPa and 160°C. The useful work input is 1,22 kJ. Assuming the surroundings are at 25°C and 100kPa, Determine, a) the exergy of the air at the initial and the final statesb) the minimum work that must be supplied for the compression processc) the second-law efficiency of this process

Apply exergy balance to closed systems and control volumes.

Is energy added to the gas by heating or removed by cooling in each cycle? Support your claim in a coherent paragraph-length response that qualitatively compares the amounts of energy added to the gas by heating or removed by cooling in the two cycles and refers to the work done on the gas and the change in internal energy of the gas.

If heating from saturated liquid to saturated vapor would occur at 100°C (373.15 K), evaluate the exergy transfers accompanying heat transfer and work, each in kJ/kg. Ans. 484, 0.