EBK THERMODYNAMICS: AN ENGINEERING APPR
8th Edition
ISBN: 9780100257054
Author: CENGEL
Publisher: YUZU
expand_more
expand_more
format_list_bulleted
Videos
Textbook Question
Chapter 11.10, Problem 24P
How is the second-law efficiency of a refrigerator operating on the vapor-compression refrigeration cycle defined? Provide two alternative definitions and explain each term.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Explain the thermodynamics cycle of a refrigerator?
A vapor compression refrigeration cycle operates at steady flow conditions with 0.25
kg/s or R-134a. The table below shows some of the operating parameters and
properties for the refrigerant. The compressor is réfrigerated, and the condenser is also
cooled with water. The compressor receives shaft power equivalent to 7.5 hp.
Neglecting changes in kinetic and potential energy changes and any heat loss between
devices, please answer the following.
a. Complete the table below and sketch the cycle processes on a T-s diagram.
When completing the table please use the same number of decimal places as in
the tables.
b.
123456
Determine the cooling capacity of the refrigeration unit, in Tons (1 refrigeration
Ton=211 kJ/min).
c. Compute the COP
d. Determine the volume flow rate of refrigerant entering the condenser in L/min.
e. Determine the mass flow rate of cooling water passing through the condenser.
1. Determine the heat transfer rate from the compressor.
g. Compute the rate of entropy…
A vapor compression refrigeration cycle operates at steady flow conditions with 0.25
kg/s or R-134a. The table below shows some of the operating parameters and
properties for the refrigerant. The compressor is refrigerated, and the condenser is also
cooled with water. The compressor receives shaft power equivalent to 7.5 hp.
Neglecting changes in kinetic and potential energy changes and any heat loss between
devices, please answer the following.
a. Complete the table below and sketch the cycle processes on a T-s diagram.
When completing the table please use the same number of decimal places as in
the tables.
123456
b. Determine the cooling capacity of the refrigeration unit, in Tons (1 refrigeration
Ton = 211 kJ/min).
c. Compute the COP.
d. Determine the volume flow rate of refrigerant entering the condenser in L/min.
e. Determine the mass flow rate of cooling water passing through the condenser.
f. Determine the heat transfer rate from the compressor.
g. Compute the rate of entropy…
Chapter 11 Solutions
EBK THERMODYNAMICS: AN ENGINEERING APPR
Ch. 11.10 - Why is the reversed Carnot cycle executed within...Ch. 11.10 - Why do we study the reversed Carnot cycle even...Ch. 11.10 - 11–3 A steady-flow Carnot refrigeration cycle uses...Ch. 11.10 - Does the ideal vapor-compression refrigeration...Ch. 11.10 - Why is the throttling valve not replaced by an...Ch. 11.10 - It is proposed to use water instead of...Ch. 11.10 - In a refrigeration system, would you recommend...Ch. 11.10 - Does the area enclosed by the cycle on a T-s...Ch. 11.10 - Consider two vapor-compression refrigeration...Ch. 11.10 - The COP of vapor-compression refrigeration cycles...
Ch. 11.10 - An ice-making machine operates on the ideal...Ch. 11.10 - A 10-kW cooling load is to be served by operating...Ch. 11.10 - 11–13 An ideal vapor-compression refrigeration...Ch. 11.10 - 11–14 Consider a 300 kJ/min refrigeration system...Ch. 11.10 - 11–16 Repeat Prob. 11–14 assuming an isentropic...Ch. 11.10 - 11–17 Refrigerant-134a enters the compressor of a...Ch. 11.10 - A commercial refrigerator with refrigerant-134a as...Ch. 11.10 - 11–19 Refrigcrant-134a enters the compressor of a...Ch. 11.10 - A refrigerator uses refrigerant-134a as the...Ch. 11.10 - The manufacturer of an air conditioner claims a...Ch. 11.10 - Prob. 23PCh. 11.10 - How is the second-law efficiency of a refrigerator...Ch. 11.10 - Prob. 25PCh. 11.10 - Prob. 26PCh. 11.10 - Prob. 27PCh. 11.10 - 11–28 Bananas are to be cooled from 28°C to 12°C...Ch. 11.10 - A vapor-compression refrigeration system absorbs...Ch. 11.10 - A refrigerator operating on the vapor-compression...Ch. 11.10 - A room is kept at 5C by a vapor-compression...Ch. 11.10 - Prob. 32PCh. 11.10 - 11–33 A refrigeration system operates on the ideal...Ch. 11.10 - When selecting a refrigerant for a certain...Ch. 11.10 - Consider a refrigeration system using...Ch. 11.10 - A refrigerant-134a refrigerator is to maintain the...Ch. 11.10 - A refrigerator that operates on the ideal...Ch. 11.10 - A heat pump that operates on the ideal...Ch. 11.10 - Do you think a heat pump system will be more...Ch. 11.10 - What is a water-source heat pump? How does the COP...Ch. 11.10 - Prob. 42PCh. 11.10 - Refrigerant-134a enters the condenser of a...Ch. 11.10 - Prob. 45PCh. 11.10 - A heat pump using refrigerant-134a heats a house...Ch. 11.10 - How does the COP of a cascade refrigeration system...Ch. 11.10 - A certain application requires maintaining the...Ch. 11.10 - Consider a two-stage cascade refrigeration cycle...Ch. 11.10 - Can a vapor-compression refrigeration system with...Ch. 11.10 - Prob. 52PCh. 11.10 - Prob. 53PCh. 11.10 - Repeat Prob. 1156 for a flash chamber pressure of...Ch. 11.10 - Prob. 56PCh. 11.10 - Prob. 57PCh. 11.10 - 11–58 Consider a two-stage cascade refrigeration...Ch. 11.10 - Prob. 59PCh. 11.10 - A two-evaporator compression refrigeration system...Ch. 11.10 - A two-evaporator compression refrigeration system...Ch. 11.10 - Repeat Prob. 1163E if the 30 psia evaporator is to...Ch. 11.10 - How does the ideal gas refrigeration cycle differ...Ch. 11.10 - Devise a refrigeration cycle that works on the...Ch. 11.10 - How is the ideal gas refrigeration cycle modified...Ch. 11.10 - Prob. 66PCh. 11.10 - How do we achieve very low temperatures with gas...Ch. 11.10 - 11–68E Air enters the compressor of an ideal gas...Ch. 11.10 - Prob. 69PCh. 11.10 - Air enters the compressor of an ideal gas...Ch. 11.10 - Repeat Prob. 1173 for a compressor isentropic...Ch. 11.10 - Prob. 73PCh. 11.10 - Prob. 74PCh. 11.10 - Prob. 75PCh. 11.10 - A gas refrigeration system using air as the...Ch. 11.10 - An ideal gas refrigeration system with two stages...Ch. 11.10 - Prob. 78PCh. 11.10 - Prob. 79PCh. 11.10 - What are the advantages and disadvantages of...Ch. 11.10 - Prob. 81PCh. 11.10 - Prob. 82PCh. 11.10 - An absorption refrigeration system that receives...Ch. 11.10 - An absorption refrigeration system receives heat...Ch. 11.10 - Heat is supplied to an absorption refrigeration...Ch. 11.10 - Prob. 86PCh. 11.10 - Prob. 87PCh. 11.10 - Prob. 88PCh. 11.10 - Prob. 89PCh. 11.10 - Consider a circular copper wire formed by...Ch. 11.10 - An iron wire and a constantan wire are formed into...Ch. 11.10 - Prob. 92PCh. 11.10 - Prob. 93PCh. 11.10 - Prob. 94PCh. 11.10 - Prob. 95PCh. 11.10 - Prob. 96PCh. 11.10 - Prob. 97PCh. 11.10 - Prob. 98PCh. 11.10 - A thermoelectric cooler has a COP of 0.18, and the...Ch. 11.10 - Prob. 100PCh. 11.10 - Prob. 101PCh. 11.10 - Prob. 102PCh. 11.10 - Prob. 103RPCh. 11.10 - Prob. 104RPCh. 11.10 - Prob. 105RPCh. 11.10 - A heat pump that operates on the ideal...Ch. 11.10 - A large refrigeration plant is to be maintained at...Ch. 11.10 - Repeat Prob. 11112 assuming the compressor has an...Ch. 11.10 - A heat pump operates on the ideal...Ch. 11.10 - An air conditioner with refrigerant-134a as the...Ch. 11.10 - An air conditioner operates on the...Ch. 11.10 - Consider a two-stage compression refrigeration...Ch. 11.10 - A two-evaporator compression refrigeration system...Ch. 11.10 - Prob. 116RPCh. 11.10 - Prob. 117RPCh. 11.10 - Prob. 118RPCh. 11.10 - Consider a regenerative gas refrigeration cycle...Ch. 11.10 - Prob. 120RPCh. 11.10 - The refrigeration system of Fig. P11122 is another...Ch. 11.10 - Repeat Prob. 11122 if the heat exchanger provides...Ch. 11.10 - An ideal gas refrigeration system with three...Ch. 11.10 - Derive a relation for the COP of the two-stage...Ch. 11.10 - Prob. 129FEPCh. 11.10 - Prob. 130FEPCh. 11.10 - Prob. 131FEPCh. 11.10 - Prob. 132FEPCh. 11.10 - An ideal vapor-compression refrigeration cycle...Ch. 11.10 - Prob. 134FEPCh. 11.10 - An ideal gas refrigeration cycle using air as the...Ch. 11.10 - Prob. 136FEPCh. 11.10 - Prob. 137FEPCh. 11.10 - Prob. 138FEP
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, mechanical-engineering and related others by exploring similar questions and additional content below.Similar questions
- Choose the correct answer: 1. In a closed or dense air refrigeration cycle, the operating pressure ratio can be reduced, which results in............ coefficient of performance. (a) lower (b) higher 2- The efficiency of Carnot heat engine is 80%. The C.O.P. of a refrigerator operating on the reversed Carnot cycle is equal to (a) 0.25 9- (b) 0.40 (c) 0.60 (d) 0.80 3. In a refrigerating machine, if the lower temperature is fixed, then the C.O.P. of the machine can be increased by (a) increasing the higher temperature (c) operating the machine at a lower speed (b) decreasing the higher temperature (d) operating the machine at a higher speed 4. The highest temperature during the cycle, in a vapour compression refrigeration system, occurs after (a) compression (b) condensation (c) expansion (d) evaporation 5- A system with multiple evaporators at different temperatures with compound compression will (a) increase the power requirements (b) reduce the power requirements (c) neither increase…arrow_forwardA standard vapor compression system produces 70.4 kW of refrigeration using R-12as a refrigerant while operating between a condenser temperature of 42 °C and anevaporator temperature of –25 °C.2.1 Draw the p-h diagram of the cycle. 2.2 Determine:(a) the refrigerating effect in kJ/kg, (b) the circulating rate in kg/s, (c) the power supplied, (d) the COP, (e) the heat rejected in kW, and(f) the volume flow rate in m3/s.arrow_forwardA 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_forward
- Data are provided for two reversible refrigeration cycles. One cycle operates between hot and cold reservoirs at 27°C and 3°C, respectively. The other cycle operates between the same hot reservoir at 27°C and a cold reservoir at -35°C. The refrigerator removes the same amount of energy by heat transfer from its cold reservoir. Determine the ratio of the net work input values of the two cycles, WCycle,2 Wcycle,1arrow_forwardMechanical EngineeringThermodynamicsTopic: Refrigeration Cyclesarrow_forwardyou design a custom refrigeration system using 1,1,2-tetrafluoroethane (R-134a) as refrigerant.You design your ideal compression-based refrigeration cycle to operate between 2 bar and 9 bar. Before enteringthe ideal butterfly valve (delta H = 0), the refrigerant is a saturated liquid. Before entering the compressor, therefrigerant is saturated vapor. In fact, in isentropic operation, the refrigerant which leaves the compressor is alsosaturated vapor. The operation of the compressor and the evaporator is isobaric. Assuming a mass flow rate of1.5 kg / s, determine the compressor efficiency required to achieve a coefficient of performance of 6.96. Whatis ?? ̇ et ?? ̇ to this performance.arrow_forward
- A refrigerator uses refrigerant-134a as the working fluid and operates on an ideal vapor-compression refrigeration cycle between 0.12 and 0.7 MPa. The mass flow rate of the refrigerant is 0.05 kg/s. Determine:a) the rate of heat removal from the refrigerated space (kW),b)the power input to the compressor (kW),c) the rate of heat rejection to the environment (kW), andd) the coefficient of performance.Submit your solution by multiplying (a)*(b)*(c)*(d) = _________.arrow_forwardA refrigerator uses refrigerant-134a as the working fluid and operates on an ideal vapor-compression refrigeration cycle between 0.12 and 0.7 MPa. The mass flow rate of the refrigerant is 0.05 kg/s. Determine: a) the rate of heat removal from the refrigerated space (kW), b)the power input to the compressor (kW), c) the rate of heat rejection to the environment (kW), and d) the coefficient of performance. Submit your solution by multiplying (a)*(b)*(c)*(d) =arrow_forwardPlease answer fastarrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Refrigeration and Air Conditioning Technology (Mi...Mechanical EngineeringISBN:9781305578296Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill JohnsonPublisher:Cengage Learning
Refrigeration and Air Conditioning Technology (Mi...
Mechanical Engineering
ISBN:9781305578296
Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson
Publisher:Cengage Learning
The Refrigeration Cycle Explained - The Four Major Components; Author: HVAC Know It All;https://www.youtube.com/watch?v=zfciSvOZDUY;License: Standard YouTube License, CC-BY