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
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Chapter 11.10, Problem 16P
A refrigerator operates on the ideal vapor-compression refrigeration cycle and uses refrigerant-134a as the working fluid. The condenser operates at 300 psia and the evaporator at 20°F. If an adiabatic, reversible expansion device were available and used to expand the liquid leaving the condenser, how much would the COP improve by using this device instead of the throttle device?
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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
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- Condensers in these refrigerators are all_______cooled.arrow_forwardThe operating condition for the single compressor in a household refrigerator is the lowest box temperature, which is typically A. 0F B. -20F C. 20F D. 40Farrow_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 heat pump that operates on the ideal vaporcompression cycle with refrigerant-134a is used to heat water from 15 to 45C at a rate of 0.12 kg/s. The condenser and evaporator pressures are 1.4 and 0.32 MPa, respectively. Determine the power input to the heat pump.arrow_forwardPlease answer step by steparrow_forwardPlease answer step by steparrow_forward
- In an ideal vapour-compression refrigeration cycle, refrigerant R-12 enters the compressor as a saturated vapour at −18 degree C and leaves the condenser as a saturated liquid at 25 degree C. The mass flow rate of the refrigerant is 0.5 kg/s, and the pressure drop in the evaporator and the condenser are negligible. Calculate: a) the refrigeration effect (rate of refrigeration or heat transfer rate in the evaporator) b)power consumed by the compressor c)the coefficient of performance of the refrigerator) d)qualityof the refrigerant after the expansion valve e)heat transfer rate in the condenserarrow_forwardNOTE: This is a multi-part question. Once an answer is submitted, you will be unable to return to this part. A refrigerator uses refrigerant-134a as the working fluid and operates on the vapor-compression refrigeration cycle. The evaporator and condenser pressures are 100 kPa and 1400 kPa, respectively. The isentropic efficiency of the compressor is 88 percent. The refrigerant enters the compressor at a rate of 0.022 kg/s superheated by 26.37°C and leaves the condenser subcooled by 4.4°C. Problem 11.021.b - Comparison to ideal vapor compression cycle Determine the rate of heat removal from the refrigerated space, the rate of heat rejection from the refrigerant to the environment, the power input, and the COP if the cycle is operated on the ideal vapor-compression refrigeration cycle between the same pressure limits. (Take the required values from saturated refrigerant-134a tables.) The rate of heat removal from the refrigerated space is kW. The rate of heat rejection from…arrow_forwardNOTE: This is a multi-part question. Once an answer is submitted, you will be unable to return to this part. A refrigerator uses refrigerant-134a as the working fluid and operates on the vapor-compression refrigeration cycle. The evaporator and condenser pressures are 100 kPa and 1400 kPa, respectively. The isentropic efficiency of the compressor is 88 percent. The refrigerant enters the compressor at a rate of 0.022 kg/s superheated by 26.37°C and leaves the condenser subcooled by 4.4°C. Problem 11.021.a - Actual refrigeration cycle Determine the rate of heat removal from the refrigerated space, the rate of heat rejection from the refrigerant to the environment, the power input, and the COP. (Take the required values from saturated refrigerant-134a tables.) The rate of heat removal from the refrigerated space is kW. The rate of heat rejection from the refrigerant to the environment is kW. The power input is kW. The COP is .arrow_forward
- 1. An ideal vapor-compression refrigeration cycle that uses refrigerant-134a as its working fluid maintains a condenser at 800 kPa and the evaporator at -12°C. Determine this system's COP and the amount of power required to service a 150 kW cooling load. Answers: 4.87, 30.8 kWarrow_forwardan ideal gas refrigeration system operates with air as the working fluid. air is at 100kpa and 20 degree celcius before compression and 500 kpa and 30 degree celcius before expansion. the system is to providearrow_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_forward
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