True Or False 5. Coefficient of performance of a reversible heat pump is always higher than that of anirreversible heat pump6. Work done in an isothermal process is greater than the work done in an isobaric process forthe same change in volume during expansion from V to 2V.7. An Ideal gas has Tc, Vc and Pc values.8. Spontaneous processes are reversible9. Rankine cycle thermal efficiency is increased by increasing the superheat before enteringturbine.

The coefficient of performance (COP) of a heat pump comprised of reversible processes (CARNOT) is…

Answered: 5. Coefficient of performance of a…

Engineering

Mechanical Engineering

5. Coefficient of performance of a reversible heat pump is always higher than that of an irreversible heat pump

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

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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?
A reversible power cycle whose thermal efficiency is 50% operates between a reservoir at 1800 K and a reservoir at a lower temperature T. Determine T, in K.
Rannkin cycle 1_The value of enthalpy at point 1 is ( h1 =?) 2_ value of enthalpy at point 2 is ( h2 =?) 3_ value of enthalpy at point 3 is ( h3 =?) 4_value of enthalpy at point 4 is ( h4 =? 5_ value of steam mass flow rate in kg/s is 6_rate of heat supplied7_ power developed by Turbine (WT) in kW is : 8_ Thermal efficiency of Rankine cycle is:
At steady state, a refrigeration cycle removes 800 kJ/min of energy by heat transfer from acold space maintained at -15o C and discharges energy by heat transfer to its surroundings at20o C. If the coefficient of performance of the actual cycle is 80 percent of that of areversible refrigeration cycle (ideal) operating between thermal reservoirs at these twotemperatures (β = 0.80 βmax), determine:a) Coefficient of performance;b) Power input to the cycle, in kW;c) Heat rejected to the surroundings.Draw sketch and show all calculations.
Part C only A gas-turbine power generator operates on an ideal air-standard Brayton cycle 1 → 2 → 3 → 4 shown in Fig. 1. The gas temperatures at the compressor inlet, compressor exit, and turbine inlet are T1 = 300 K, T2 = 600 K, and T3 = 1200 K, respectively. Solve Part C below using the variable specific heat assumption. Part C - Determine the heat input qin in the process 2 → 3, the work wC used by the compressor, and the work wT produced by the turbine per kg of air.
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In a vapor-compression refrigeration cycle, ammonia exits the evaporator as saturated vapor at -22°C. The refrigerant enters the condenser at 16 bar and 190°C, and saturated liquid exits at 16 bar. There is no significant heat transfer between the compressor and its surroundings, and the refrigerant passes through the evaporator with a negligible change in pressure.If the refrigerating capacity is 50 kW, determine:(a) the mass flow rate of the refrigerant, in kg/s.(b) the power input to the compressor, in kW.(c) the coefficient of performance.(d) the isentropic compressor efficiency, in percent.(e) the rate of entropy production, in kW/K, for the compressor.
As shown in the figure, an air conditioner operating at steady state maintains a dwelling at 70°F on a day when the outside temperature is 90°F. The rate of heat transfer into the dwelling through the walls and roof is 30,000 Btu/h and the net power input to the air conditioner compressor is 3 hp. Determine a. the coefficient of performance for the air conditioner b. power input required in hp c. coefficient of performance for a reversible air conditioner providing the same cooling effect while operating between the same cold and hot temperatures.
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Thermodynamics Apply the steady flow energy equation to plant equipment.
Use the following conversions where necessary:1hp = 745.7W; ρwater = 1000 kg/m3; ρmercury = 13600 kg/m3; 1 atm = 101.325 kPa; Cp (water) = 4.18 kJ/kg °C; g = 9.81m/s2; For properties of air, use R = 0.287 kJ/kg K; Cv (air) = 0.718 kJ/kg K; Cp (air) =1.005 kJ/kg K A cogeneration power plant operating in a thermodynamic cycle at steady state. The plant provides electricity to a community at a rate of 80 MW. The energy discharged from the power plant by heat transfer is denoted on the figure by . Of this, 70 MW is provided to the community for water heating and the remainder is discarded to the environment without use. The electricity is valued at $0.08 per kWh. If the cycle thermal efficiency is 40 %, determine the i. rate energy is added by heat transfer, , in MW ii. rate energy is discarded to the environment, in MW iii. value of the electricity generated, in $ per year
As shown in the figure, Refrigerant 22 enters the compressor of an air conditioning unit operating at steady state at 40oF, 80 lbf/in2 and is compressed to 160oF, 200 lbf/in2. The refrigerant exiting the compressor enters a condenser where energy transfer to air as a separate stream occurs, and the refrigerant exits as a liquid at 200 lbf/in2, 90oF. Air enters the condenser at 75oF, 14.7 lbf/in2 with a volumetric flow rate of 1500 ft3/min and exits at 110oF. Neglect stray heat transfer and kinetic and potential energy effects, and assume ideal gas behavior for the air.