Why do we study the reversed Carnot cycle even though it is not a realistic model for refrigeration cycles?
Why do we study the reversed Carnot cycle even it is not a realistic model for refrigeration cycles.
Explanation of Solution
A reversed Carnot cycle consists of an isentropic and isothermal process. Generally, the reversed Carnot cycle cannot be used an ideal model for refrigeration purpose since the isentropic process needed a maximum operational speed, but the isothermal process needed a very less operational speed.
But this cycle acts as a realistic model against which refrigeration cycles can be related. Also, the coefficient of performance of the reversed Carnot cycle gives the upper limit for the coefficient of performance of a refrigeration cycle which is functioning between the definite temperature limits.
Hence, the reversed Carnot cycle is considered for refrigeration cycles.
Want to see more full solutions like this?
Chapter 11 Solutions
CENGEL'S 9TH EDITION OF THERMODYNAMICS:
Additional Engineering Textbook Solutions
INTERNATIONAL EDITION---Engineering Mechanics: Statics, 14th edition (SI unit)
Fundamentals of Aerodynamics
Mechanics of Materials
Shigley's Mechanical Engineering Design (McGraw-Hill Series in Mechanical Engineering)
Heating Ventilating and Air Conditioning: Analysis and Design
Fundamentals Of Thermodynamics
- A heat pump cycle using water as the working fluid consists of a compressor, a condenser, an expansion valve, and an evaporator. Saturated vapor with mass flow rate of 1 kg/s at 0.5 MPa (state 1) enters the condenser and leaves it as saturated liquid at the same pressure (state 2). The pressure in the evaporator is 0.01 MPa. The condenser and the evaporator processes are isobaric. The compressor is adiabatic and reversible. The valve is adiabatic. A. List all the known information and assumptions. B. Determine the heat output of the condenser (QH) C. Determine the heat input of the evaporator(Qc) D. Determine the coefficient of performance of the heat pump. E. Determine the coefficient of performance of a Carnot heat pump running between the same temperatures TH and TC at the evaporator and condenser. F. Calculate the entropy generation in the compressor. G. Draw the TS diagram for the cycle on paper. (Hint: you must calculate T1, T2, T3, T4, h1, h2, h3, h4, s1, s2, s3, s4, and draw…arrow_forwardA steam power-plant, with a power of "Wnet", is working according to the Rankine cycle. Steam enters the system in "P3"MPa pressure and 500 C degree temperature, and cooled down in condenser at 10 kPa pressure. Take Source temperature as "TH", and sink temperature 290 K. According to the information given. P3 = 6 MPa, %3D Wnet = 201 MW, TH = 1600 K Determine: 1.Heat generated (MW)(Not Heat given) 2.Pump entrophy generation (MW/K) 3.Combustion chamber entrophy generation (MW/K) 4.Turbine entrophy generation (MW/K)arrow_forwardWhat is Carnot cycle, Rankine cycle and Refrigeration cycle?arrow_forward
- can u explain and be fast pleasearrow_forward4. A reversed Carnot cycle is used for refrigeration and rejects 1000kW of heat at 670 while receiving heat at -23C. Determine (a) COP, (b) the power required and (c) the refrigerating effect.arrow_forwardAn ideal vapor compression cycle operates between the temperature limits of -5 °C and 30 °C and uses R134a as the refrigerant, which flows at a rate of 0.6 kg/s. The refrigeration capacity of this refrigerator is.... kW to one decimal place.arrow_forward
- Suppose you will install an air conditioner inside your room, Where should you install the appliance to attain maximum efficiency? Justify your answer.arrow_forwardPlease answer fastarrow_forward4. A Camot heat pump with refrigerant-134a as the working fluid is used to keep a room at 78*F by absorbing heat from geothermal liquid water that enters the evaporator at 60°C at a rate of 3.78 kg/min and leaves (still as a liquid) at 40°c The refrigerant, meanwhile, enters the evaporator at 12°C with a quality of 25% and leaves at the same pressure as saturated vapor. If the compressor consumes 1.8 kW of power, detemine (a) the mass flow rate (in kg/s) of the refrigerant at the evaporator, (b) the rate of heat (in kW) supplied to maintain the room temperature, and (c) the COP. Also, what is (d) the ambient temperature at the outside, in "C, that necessitates the use of the heat pump? Assume steam properties to compute for the thermodynamic conditions of geothermal water. Outside Inside Expansion Ve Condenser Evaporator Compresserarrow_forward
- I need answer within 10 minutes pleasearrow_forwardWHAT IS THE BASIC DIFFERENCE BETWEEN A REFRIGERATION SYSTEM APPLIED IN AN AIR CONDITIONING AND IN THE HOUSEHOLD REFRIGERATOR?arrow_forwardA gas refrigeration system using air as the working fluid has a pressure ratio of 5 (see Fig. Q 1). Air enters the compressor at 0°C. The high-pressure air is cooled to35 oC by rejecting heat to the surroundings. The refrigerant leaves the turbine at -80 oC and enters the refrigerated space where it absorbs heat before entering the regenerator. The mass flow rate of air is 0.4 kg/s. Assuming isentropic efficiencies of 0.8 for the compressor and 0.85 for the turbine and variable specific heats.Draw accurately the cycle on a T-s diagram with properly labelled property values. Determine(a) the effectiveness of the regenerator,(b) the rate of heat removal from the refrigerated space, and(c) the COP of the cycle. Also, determine(d) the refrigeration load and the COP if this system operated on the simple gas refrigeration cycle.Use the same compressor inlet temperature as given, the same turbine inlet temperature as calculated, and the same compressor and turbine efficiencies. Draw the T-s…arrow_forward
- Refrigeration and Air Conditioning Technology (Mi...Mechanical EngineeringISBN:9781305578296Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill JohnsonPublisher:Cengage Learning