Thermodynamics: An Engineering Approach ( 9th International Edition ) ISBN:9781260092684
9th Edition
ISBN: 9781260048667
Author: Yunus A. Cengel Dr.; Michael A. Boles
Publisher: McGraw-Hill Education
expand_more
expand_more
format_list_bulleted
Videos
Textbook Question
Chapter 11.10, Problem 140FEP
An ideal gas refrigeration cycle using air as the working fluid operates between the pressure limits of 80 and 280 kPa. Air is cooled to 35°C before entering the turbine. The lowest temperature of this cycle is
- (a) −58°C
- (b) −26°C
- (c) 5°C
- (d) 11°C
- (e) 24°C
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
An ideal gas refrigeration cycle with a pressure ratio of four uses air as the working fluid.
Air enters the compressor at 100 kPa and 0°C and the turbine at 50 °C. Determine (a) the temperature at the turbine exit, (b) the heat removed per unit mass of the air, and (c) the COP
of the cycle. Use constant specific heat for air at room temperature with cp = 1.005 kJ/kg.K
and k = 1.4.
An ideal gas refrigeration cycle using air as the working fluid operates between the pressure limits of 80 kPa and 280 kPa. Air is cooled to
TB
35°C before entering the turbine. The lowest temperature of this cycle is (Hint:
k-1
PB
k
TA
PA
0°C
11°C
24°C
-58°C
-26°C
O O O O
A vapor-compression refrigeration cycle with refrigerant-134a as the working fluid is used to maintain a
space at -13°C by rejecting heat to ambient air at 27°C. R-134a enters the compressor at 100 kPa
superheated by 6.4°℃ at a rate of 0.05 kg/s. The isentropic efficiency of the compressor is 85 percent.
The refrigerant leaves the condenser at 39.4ºC as a saturated liquid. Determine
a) the rate of cooling provided
b) the COP of the system
c) the minimum power input required
Chapter 11 Solutions
Thermodynamics: An Engineering Approach ( 9th International Edition ) ISBN:9781260092684
Ch. 11.10 - Why do we study the reversed Carnot cycle even...Ch. 11.10 - Why is the reversed Carnot cycle executed within...Ch. 11.10 - A steady-flow Carnot refrigeration cycle uses...Ch. 11.10 - Refrigerant-134a enters the condenser of a...Ch. 11.10 - Does the ideal vapor-compression refrigeration...Ch. 11.10 - Why is the throttling valve not replaced by an...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 - It is proposed to use water instead of...
Ch. 11.10 - The COP of vapor-compression refrigeration cycles...Ch. 11.10 - A 10-kW cooling load is to be served by operating...Ch. 11.10 - An ice-making machine operates on the ideal...Ch. 11.10 - An air conditioner using refrigerant-134a as the...Ch. 11.10 - An ideal vapor-compression refrigeration cycle...Ch. 11.10 - A refrigerator operates on the ideal...Ch. 11.10 - A refrigerator uses refrigerant-134a as the...Ch. 11.10 - An ideal vapor-compression refrigeration cycle...Ch. 11.10 - A refrigerator uses refrigerant-134a as its...Ch. 11.10 - A refrigerator uses refrigerant-134a as the...Ch. 11.10 - A commercial refrigerator with refrigerant-134a as...Ch. 11.10 - The manufacturer of an air conditioner claims a...Ch. 11.10 - Prob. 24PCh. 11.10 - How is the second-law efficiency of a refrigerator...Ch. 11.10 - Prob. 26PCh. 11.10 - Prob. 27PCh. 11.10 - Prob. 28PCh. 11.10 - Bananas are to be cooled from 28C to 12C at a rate...Ch. 11.10 - A vapor-compression refrigeration system absorbs...Ch. 11.10 - A room is kept at 5C by a vapor-compression...Ch. 11.10 - Prob. 32PCh. 11.10 - A refrigerator operating on the vapor-compression...Ch. 11.10 - When selecting a refrigerant for a certain...Ch. 11.10 - A refrigerant-134a refrigerator is to maintain the...Ch. 11.10 - Consider a refrigeration system using...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 - A heat pump operates on the ideal...Ch. 11.10 - Refrigerant-134a enters the condenser of a...Ch. 11.10 - A heat pump that operates on the ideal...Ch. 11.10 - The liquid leaving the condenser of a 100,000...Ch. 11.10 - Reconsider Prob. 1144E. What is the effect on the...Ch. 11.10 - A heat pump using refrigerant-134a heats a house...Ch. 11.10 - A heat pump using refrigerant-134a as a...Ch. 11.10 - Reconsider Prob. 1148. What is the effect on the...Ch. 11.10 - Prob. 50PCh. 11.10 - How does the COP of a cascade refrigeration system...Ch. 11.10 - Consider a two-stage cascade refrigeration cycle...Ch. 11.10 - Can a vapor-compression refrigeration system with...Ch. 11.10 - Prob. 54PCh. 11.10 - A certain application requires maintaining the...Ch. 11.10 - Prob. 56PCh. 11.10 - Repeat Prob. 1156 for a flash chamber pressure of...Ch. 11.10 - Prob. 59PCh. 11.10 - A two-stage compression refrigeration system with...Ch. 11.10 - A two-stage compression refrigeration system with...Ch. 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 - Consider a two-stage cascade refrigeration cycle...Ch. 11.10 - How does the ideal gas refrigeration cycle differ...Ch. 11.10 - Prob. 67PCh. 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. 70PCh. 11.10 - How do we achieve very low temperatures with gas...Ch. 11.10 - An ideal gas refrigeration system operates with...Ch. 11.10 - Air enters the compressor of an ideal gas...Ch. 11.10 - Repeat Prob. 1173 for a compressor isentropic...Ch. 11.10 - An ideal gas refrigeration cycle uses air as the...Ch. 11.10 - Rework Prob. 1176E when the compressor isentropic...Ch. 11.10 - A gas refrigeration cycle with a pressure ratio of...Ch. 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. 81PCh. 11.10 - Prob. 82PCh. 11.10 - What are the advantages and disadvantages of...Ch. 11.10 - Prob. 84PCh. 11.10 - Prob. 85PCh. 11.10 - Prob. 86PCh. 11.10 - Prob. 87PCh. 11.10 - Heat is supplied to an absorption refrigeration...Ch. 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. 92PCh. 11.10 - Prob. 93PCh. 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. 96PCh. 11.10 - Prob. 97PCh. 11.10 - Prob. 98PCh. 11.10 - Prob. 99PCh. 11.10 - Prob. 100PCh. 11.10 - Prob. 101PCh. 11.10 - Prob. 102PCh. 11.10 - A thermoelectric cooler has a COP of 0.18, and the...Ch. 11.10 - Prob. 104PCh. 11.10 - Prob. 105PCh. 11.10 - Prob. 106PCh. 11.10 - Rooms with floor areas of up to 15 m2 are cooled...Ch. 11.10 - Consider a steady-flow Carnot refrigeration cycle...Ch. 11.10 - Consider an ice-producing plant that operates on...Ch. 11.10 - A heat pump that operates on the ideal...Ch. 11.10 - A heat pump 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 - An air conditioner with refrigerant-134a as the...Ch. 11.10 - A refrigerator using refrigerant-134a as the...Ch. 11.10 - Prob. 117RPCh. 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 - The refrigeration system of Fig. P11122 is another...Ch. 11.10 - Repeat Prob. 11122 if the heat exchanger provides...Ch. 11.10 - An aircraft on the ground is to be cooled by a gas...Ch. 11.10 - Consider a regenerative gas refrigeration cycle...Ch. 11.10 - An ideal gas refrigeration system with three...Ch. 11.10 - Prob. 130RPCh. 11.10 - Derive a relation for the COP of the two-stage...Ch. 11.10 - Prob. 133FEPCh. 11.10 - Prob. 134FEPCh. 11.10 - Prob. 135FEPCh. 11.10 - Prob. 136FEPCh. 11.10 - Prob. 137FEPCh. 11.10 - An ideal vapor-compression refrigeration cycle...Ch. 11.10 - Prob. 139FEPCh. 11.10 - An ideal gas refrigeration cycle using air as the...Ch. 11.10 - Prob. 141FEPCh. 11.10 - Prob. 142FEP
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
- 1. An ideal-gas refrigeration cycle uses air as the working fluid to maintain a refrigerated space at - 30°C while rejecting heat to the surrounding medium at 30°C. If the pressure ratio of the compressor is 3 and the polytropic index is 1.3 for both compressor and expander, determine the minimum temperature in the cycle for a mass flow rate of 0.03 kg/s. °Carrow_forwardRefrigerant-134a enters the compressor of a refrigerator at 140 kPa and -10°C at a rate of 0.3 m3/min and leaves at 1 MPa. The isentropic efficiency of the compressor is 78 percent. The refrigerant enters the throttling valve at 0.95 MPa and 30°C and leaves the evaporator as saturated vapor at -18.5°C. Show the cycle on a T-s diagram with respect to saturation lines, and determine (a) the power input to the compressor, (b) the rate of heat removal from the refrigerated space, and (c) the pressure drop andrate of heat gain in the line between the evaporator and the compressor. answers 1.88 kW, 7.11 kW, 1.72 kPa, 0.24 kWarrow_forwarda) A freezer working on an ideal vapour-compression refrigeration cycle uses refrigerant R- 134a with a mass flow rate of 0.10 kg/s. The refrigerant leaves the evaporator as saturated vapour at a temperature of -8 °C. It leaves the condenser as saturated liquid at a pressure of 0.8 MPa. Determine the power required to drive the compressor. Note that the thermodynamic properties of R-134a are attached at the end of the paper. 0.8 MPa A Figure Q4 b) A freezer wall is made of a composite material with a thickness of 20 mm and a conductivity of 0.03 W/m-K. Air temperatures inside and outside the freezer are -6 °C and 20 °C, respectively. The convection coefficient is 2 W/m² K on both the inner and outer surfaces of the freezer wall. Determine the heat flux through the freezer wall. -8 Carrow_forward
- A refrigerator uses refrigerant-134a as the working fluid and operates on an ideal vapor-compression refrigeration cycle between 0.12 and 0.9 MPa. The mass flow rate of the refrigerant is 0.05 kg/s which exits the condenser as saturated liquid. (a) Show the cycle on a P-h and T-s diagram with respect to saturation lines. (b) Determine the rate of heat removal from the refrigerated space and the power input to the compressor, and (c) the coeifficient of performance.arrow_forward2. Refrigerant-134a enters the compressor of a refrigerator at 100 kPa and -20°C at a rate of 0.5 m³/min and leaves at 0.8 MPa. The isentropic efficiency of the compressor is 78 percent. The refrigerant enters the throttling valve at 0.75 MPa and 26°C and leaves the evaporator as saturated vapor at 26°C. Show the cycle on a T-s diagram with respect to saturation lines, and determine (a) the power input to the compressor, (b) the rate of heat removal from the refrigerated space, and (c) the pressure drop and rate of heat gain in the line between the evaporator and the compressor. Answers: (a) 2.40 kW, (b) 6.17 kW, (c) 1.73 kPa, 0.203 kWarrow_forwardAn ideal vapor-compression refrigeration cycle with refrigerant-134a as the working fluid operates between pressure limits of 200 and 1600 kPa. The refrigerant absorbs heat from a space at 3°C and rejects heat to ambient air at 27 °C. Determine (a) the heat absorbed in the evaporator and the work input, (b) the COP, (c) the exergy destruction in each component of the cycle and the total exergy destruction in the cycle, (d) the second-law efficiency of the cycle.arrow_forward
- In a Rankine cycle with reheating, the steam leaves the boiler at 2.5 MPa and 600 ºC and enters the high pressure turbine where it expands to a pressure of 1 MPa to be then subjected to a reheating process from where it leaves at 1 MPa and 600 ° C. The steam at these conditions enters the low pressure turbine and expands up to the condenser pressure of 50 kPa. The heat that is extracted in the condenser is 1500 kJ / s. If the adiabatic efficiency of the turbines and the pump is 95%, determine the total heat flow in kJ / s delivered to the boiler.arrow_forwardAn ideal ammonia (R – 717) vapor-compression refrigeration cycle has an evaporator temperature of –20 C and a condenser pressure of 12 bar. Saturated vapor enters the compressor, and saturated liquid exits the condenser. The mass flow rate of the refrigerant is 3 kg/min. Determine the temperature of the superheated ammonia vapor exiting the compressor.arrow_forwardvapor-compression A water cooler based on the refrigeration cycle uses refrigerant R- 134a as the working fluid, and the refrigerator operates in 35°C surroundings. The condenser and evaporator pressures are 1.2 MPa and 180 kPa, respectively, and the isentropic efficiency of the compressor is 80%. The air conditioner is being used to cool a 6 liter/minute (LPM) stream of liquid water from 35°C down to 1°C. Find the power input needed to drive the compressor (answer: 5.63 kW). Use Cengel's R-134a tables posted on Canvas to model the refrigerant. Expansion Valve Tour 1°C 0 35°C Surroundings QCONDENSER Condenser 1.2 MPa Evaporator 180 kPa EVAPORATOR 6 LPM of Water Compressor TIN = 35°C W COMPRESSORarrow_forward
- In a Rankine cycle with reheating, the steam leaves the boiler at 2.5 MPa and 600 ºC and enters the high-pressure turbine where it expands to a pressure of 1 MPa to be then subjected to a reheating process from where it leaves at 1 MPa and 600 ° C. The steam at these conditions enters the low-pressure turbine and expands up to the condenser pressure of 50 kPa. The heat that is extracted in the condenser is 1500 kJ / s. If the adiabatic efficiency of the turbines and the pump is 95%, determine the total heat flow in kJ / s delivered to the boiler.arrow_forwardConsider a gas refrigeration system with air as the working fluid. The pressure ratio is 5.5. Air enters the compressor at 0°C. The high-pressure air is cooled to 35 °C by rejecting heat to the surroundings. The refrigerant leaves the turbine at -95°C and then it absorbs heat from the refrigerated space before entering the regenerator. The mass flow rate of air is 0.55 kg/s. Assuming isentropic efficiencies of 90% for both the compressor and the turbine, 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. In this cycle, take the compressor and turbine inlet temperatures to be 0 and 35 °C, respectively, and use the same compressor and turbine efficiencies. Use constant specific heat for air at room temperature with Cp = 1.005 kJ/kg K and k = 1.4.arrow_forwardA vapor compression cycle with R-134a is being used as its refrigerant. The refrigerant leaves the evaporator at -10 C and 120 kPa and it enters the condenser 1.0 MPa. Assuming there is a heat loss due to compression which is equal to 20 kJ/kg, and it has a cooling capacity of 75 tons of refrigeration, Determine the following: (a)heat rejected (b)cooling effect (c)work of compression (d) coefficient of performance (e)volume flow rate of refrigerant (f)compressor discharge temperaturearrow_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