CONNECT FOR THERMODYNAMICS: AN ENGINEERI
9th Edition
ISBN: 9781260048636
Author: CENGEL
Publisher: MCG
expand_more
expand_more
format_list_bulleted
Videos
Textbook Question
Chapter 11.10, Problem 80P
An ideal gas refrigeration system with two stages of compression with intercooling as shown in Fig. P11–80 operates with air entering the first compressor at 90 kPa and −24°C. Each compression stage has a pressure ratio of 3, and the two intercoolers can cool the air to 5°C. Calculate the coefficient of performance of this system and the rate at which air must be circulated through this system to service a 45,000 kJ/h cooling load. Use constant specific heats at room temperature.
FIGURE P11–80
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
An ammonia vapor refrigeration cycle operates at an evaporator temperature of -16°C and a condensing temperature of 32°C. Determine the coefficient of performance for wet compression with superheated vapor leaving the compressor. The quality of vapor entering the compressor is 0.975 and the specific entropy of the superheated vapor discharging from the compressor is 5.7 kJ/kg-K.
A 540,000 kJ/h capacity refrigeration system using Refrigerant 22 and served by a single
compressor unit operates at an evaporator temperature of -23
oC and a condensing saturation
temperature 40oC. To get rid of the single compressor load, a modification is proposed to use two
stage of compression with refrigerant intercooling.
(a) Determine the power required in the original system.
(b) Determind the power required for the proposed modified system.
A 100 x 300 mm ammonia compressor with a compression efficiency of 82% operates with a suction pressure of 291.57 kPa and a condenser pressure of 1203.7 kPa at 30 rps. The refrigerant cools 100 kg/min of water from 250C to 20C and assuming 5% of the useful refrigerating effect is lost due to the process of cooling, give that,
h2 = 1653 kJ/kg, h1 = 1450.22 kJ/kg, h3 = 346.614 kJ/kg, v1 = 417.477 L/kg
determine:
a.) RE in tons of refrigeration
b.) mass flow rate of ammonia
c.) actual work of compression kW
d.) find Brake work (kW) if mechanical eff is 90%
e.) Actual volumetric eff
f.) clearance volumetric eff if c=6%
Chapter 11 Solutions
CONNECT FOR THERMODYNAMICS: AN ENGINEERI
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
- A 3 cylinder 100 x 200 mm ammonia compressor with a compression efficiency of 86% operates with a suction pressure of 291.57 kPa and a condenser pressure of 1557 kPa at 18 rps. The refrigerant cools 1.8 kg/s of water from 28 0C to 3 0C and assuming 7 % of the useful refrigerating effect is lost due to the process of cooling and h2 = 1710 kJ/kg and clearance volume is 7 %. determine: (D) ideal COP (E) actual work of comprssion (F) actual COParrow_forwardA 3 cylinder 100 x 200 mm ammonia compressor with a compression efficiency of 86% operates with a suction pressure of 291.57 kPa and a condenser pressure of 1557 kPa at 18 rps. The refrigerant cools 1.8 kg/s of water from 28 0C to 3 0C and assuming 7 % of the useful refrigerating effect is lost due to the process of cooling and h2 = 1710 kJ/kg and clearance volume is 7 %. determine: G. volume flow rate at suction H. displacement volume I. clearance volumetric efficiency J. actual volumetric efficiencyarrow_forwardA 3 cylinder 100 x 200 mm ammonia compressor with a compression efficiency of 86% operates with a suction pressure of 291.57 kPa and a condenser pressure of 1557 kPa at 18 rps. The refrigerant cools 1.8 kg/s of water from 28 0C to 3 0C and assuming 7 % of the useful refrigerating effect is lost due to the process of cooling and h2 = 1710 kJ/kg and clearance volume is 7 %. determine: A. Refrigerating capacity B. mass flow of ammonia C. ideal work of compressionarrow_forward
- The two-stage compression refrigeration system shown below is used to remove heat from refrigerated space using R-410a as the coolant. The R-410a leaves the evaporator at state 1 and is first compressed in a low-pressure compressor (W, Pc=-250 kW) to an intermediate pressure of 933.9 kPa before it is mixed with saturated vapor and then further compressed in a high-pressure compressor to 3000 kPa. Heat is then removed from the R-410a as it passes through the heat exchanger and exchanges heat with cooling water. The R-410a is then expanded in the throttling valve to the intermediate pressure and passed through a type of mixing chamber called a flash chamber where it is separated into a saturated vapor leaving at state 7 and a saturated liquid leaving at state 8. Finally, the liquid is expanded before entering the evaporator at state 9. Note that the mass flow rate of R-410a leaving the mixing chamber is mypC = 10 kg/s. Neglect changes in kinetic and potential energy across all devices…arrow_forwardA 300-HP engine with a thermal efficiency of 30% is using a remote radiator which absorbs 25% of the heat supplied to the engine. Cooling system with cooling tower is used with a cooling range of 5°C. The temperature rise of the water after passing the remote radiator is 10°C. Air enters the cooling tower at 32°C dry-bulb; 26°C wet-bulb temperatures and leaves the tower at 36°C & 70%RH. Make a schematic diagram of the system, the process in the provided psychrometric chart and calculate the following: (a.) The water flow rate in the cooling tower in liters per hour; and (b.) If the heat absorbed by air is 20% of heat absorbed by the cooling tower water, what is the air flow needed in cu.m/hour.arrow_forward: Refrigerant 134a enters a compressor of a vapour compression of a refrigeration cycle at 120Kpa as a saturated vapour and leaves at 900 Kpa and 75oc. The refrigerant leaves the condenser as a saturated liquid. The rate of cooling provided by the system is 18000 Btu/hr. Determine (1) Mass flow rate of R134a (2) The Cop of the cycle (3) Also determine the Cop of the cycle if the expansion valve is replaced by an isentropic turbine. Do you recommend such a replacement for the refrigeration system? (4) Determine the Cop if the evaporator pressure is 160Kpa and otheer values remains the same. (5) Determine the Cop if the condenser pressure is 800 Kpa and other values remain the same.arrow_forward
- A geothermal heat pump running a simple heat pump cycle uses R-134a as the refrigerant and sources thermal energy from well water. The well water enters the evaporator at 13°C and exits at 7°C, with negligible pressure drop. On the refrigerant side, the evaporator operates isobarically at 320 kPa and the refrigerant exits the evaporator at 10°C. The refrigerant is compressed to 1200 kPa through the compressor, which has an isentropic efficiency of 90%. In the condenser, air absorbs energy from the refrigerant at a rate of 4.5 tons (1 ton = 211 kJ/min) as its temperature increases from 22°C at the condenser inlet to 42°C at the condenser outlet. The condenser operates isobarically, and the refrigerant exits the condenser at 20°C. Calculate the input power to the compressor and the COP of the heat pump.arrow_forwardA six-cylinder refrigerant 22 compressor operating at 29 r/s indicate a refrigerating capacity of 96.4 kW and a power requirement of 28.9 kW at an evaporating temperature of 5°C and condensing temperature of 50°C. The performance data are based on 3°C liquid sub-cooling and 8°C superheating of the suction gas entering the compressor. The cylinder bore is 67 mm and the piston stroke is 57 mm. Compute (a) the clearance volumetric efficiency if the clearance volume is 4.8 percent, (b) the actual volumetric efficiency, and (c) the compression efficiency.arrow_forwardA 55 kW refrigeration load is to be carried by an air refrigeration system with a discharge pressure of 1370 kPa and a refrigerator pressure of 345 kPa. Compression and expansion processes are polytropic with n-1.37. The pressure at the start of the expansion is 1344 kPa and the temperature is 32°C. Air temperature leaving the refrigerator is 0°C and entering the compressor is 5°C. Clearance for both compressor and expander is 5%.Determine the (a) The piston displacement of the compressor and expander.arrow_forward
- A 100 x 200 mm ammonia compressor with a compression efficiency of 82% operates with a suction pressure of 291.57 kpa and a condenser pressure of 1203.7 kPa at 22 rps. The refrigerant cools 100 kg/min of water from 25°C to 2°C and assuming 5% of the useful refrigerating effect is lost due to the process of cooling, determine: a) RE in tons of refrigeration hz = 1653 kJ/kg b) mass flow rate of ammonia c) actual work of compression kW d) find Brake work (kW) if mechanical eff is 90% e) Actual volumetric eff f) clearance volumetric eff if c=6%arrow_forward1. 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_forwardAn air-standard cycle with variable specific heats is executed in a closed system with 0.003 kg of air, and it consists of the following three processes: 1-2 Isentropic compression from 3-1 v = constant heat rejection to initial state (a) Show the cycle on P-v and T-s diagrams. (b) Calculate the maximum temperature in the cycle. (c) Determine the thermal efficiency.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Elements Of ElectromagneticsMechanical EngineeringISBN:9780190698614Author:Sadiku, Matthew N. O.Publisher:Oxford University Press
Mechanics of Materials (10th Edition)Mechanical EngineeringISBN:9780134319650Author:Russell C. HibbelerPublisher:PEARSON
Thermodynamics: An Engineering ApproachMechanical EngineeringISBN:9781259822674Author:Yunus A. Cengel Dr., Michael A. BolesPublisher:McGraw-Hill Education
Control Systems EngineeringMechanical EngineeringISBN:9781118170519Author:Norman S. NisePublisher:WILEY
Mechanics of Materials (MindTap Course List)Mechanical EngineeringISBN:9781337093347Author:Barry J. Goodno, James M. GerePublisher:Cengage Learning
Engineering Mechanics: StaticsMechanical EngineeringISBN:9781118807330Author:James L. Meriam, L. G. Kraige, J. N. BoltonPublisher:WILEY
Elements Of Electromagnetics
Mechanical Engineering
ISBN:9780190698614
Author:Sadiku, Matthew N. O.
Publisher:Oxford University Press
Mechanics of Materials (10th Edition)
Mechanical Engineering
ISBN:9780134319650
Author:Russell C. Hibbeler
Publisher:PEARSON
Thermodynamics: An Engineering Approach
Mechanical Engineering
ISBN:9781259822674
Author:Yunus A. Cengel Dr., Michael A. Boles
Publisher:McGraw-Hill Education
Control Systems Engineering
Mechanical Engineering
ISBN:9781118170519
Author:Norman S. Nise
Publisher:WILEY
Mechanics of Materials (MindTap Course List)
Mechanical Engineering
ISBN:9781337093347
Author:Barry J. Goodno, James M. Gere
Publisher:Cengage Learning
Engineering Mechanics: Statics
Mechanical Engineering
ISBN:9781118807330
Author:James L. Meriam, L. G. Kraige, J. N. Bolton
Publisher:WILEY
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