EBK THERMODYNAMICS: AN ENGINEERING APPR
9th Edition
ISBN: 8220106796979
Author: CENGEL
Publisher: YUZU
expand_more
expand_more
format_list_bulleted
Textbook Question
Chapter 5.5, Problem 58P
Why are throttling devices commonly used in refrigeration and air-conditioning applications?
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solutionStudents have asked these similar questions
1. A refrigeration system using R-22 has a capacity of 320 kW of refrigeration.
The evaporating temperature is -10°C and the condensing temperature is
40°C. Calculate the fraction of vapor in the mixture before the evaporator.
Properties of R-22:
At -10°C; hg = 401.60 kJ/kg, hf = 188.43 kJ/kg
At 40°C; hf 249.69 kJ/kg
A Freon 12 vapour compression system operating at a condenser temperature of
40°C and an evaporator temperature of 0°C develops 15 tons of refrigeration.
Using the p-h diagram for Freon 12, determine.
(a) the discharge temperature and mass flow rate of the refrigerant circulated,
Properties of Carbon Dioxide:
h @ 220 KPa and -5°C = 350 KJ/kg
hi @ 25°C = 223.65 KJ/kg
h: @ 22°C = 220.75 KJ/kg
ha @ 220 KPa = 347.13 KJ/kg
%3D
Saturated Vapor Carbon Dioxide refrigerant at 220 KPa leaves the evaporator and
enters the compressor at -5 °C. The refrigerant leaves the condenser as saturate liquid
at 25 °C and enters the expansion valve at 22 °C. Heat rejected from the condenser
amount 90 KW. The work to the compressor is 60 KJ/kg while the heat lost from the
compressor is 5 KJ/kg. If 2.5 KJ/kg of heat are lost in the piping between the
compressor and condenser.
Solve for QA in KW.
Chapter 5 Solutions
EBK THERMODYNAMICS: AN ENGINEERING APPR
Ch. 5.5 - Name four physical quantities that are conserved...Ch. 5.5 - Define mass and volume flow rates. How are they...Ch. 5.5 - Does the amount of mass entering a control volume...Ch. 5.5 - Consider a device with one inlet and one outlet....Ch. 5.5 - The ventilating fan of the bathroom of a building...Ch. 5.5 - Air enters a 16-cm-diameter pipe steadily at 200...Ch. 5.5 - A steam pipe is to transport 200 lbm/s of steam at...Ch. 5.5 - A garden hose attached with a nozzle is used to...Ch. 5.5 - A steady-flow compressor is used to compress...Ch. 5.5 - Air enters the 1-m2 inlet of an aircraft engine at...
Ch. 5.5 - A 2-m3 rigid tank initially contains air whose...Ch. 5.5 - Air enters a nozzle steadily at 2.21 kg/m3 and 40...Ch. 5.5 - A spherical hot-air balloon is initially filled...Ch. 5.5 - Water enters the constant 130-mm inside-diameter...Ch. 5.5 - A desktop computer is to be cooled by a fan whose...Ch. 5.5 - A hair dryer is basically a duct of constant...Ch. 5.5 - Refrigerant-134a enters a 28-cm-diameter pipe...Ch. 5.5 - What are the different mechanisms for transferring...Ch. 5.5 - How do the energies of a flowing fluid and a fluid...Ch. 5.5 - An air compressor compresses 6 L of air at 120 kPa...Ch. 5.5 - A house is maintained at 1 atm and 24C, and warm...Ch. 5.5 - Refrigerant-134a enters the compressor of a...Ch. 5.5 - Steam is leaving a pressure cooker whose operating...Ch. 5.5 - How is a steady-flow system characterized?Ch. 5.5 - Can a steady-flow system involve boundary work?Ch. 5.5 - A diffuser is an adiabatic device that decreases...Ch. 5.5 - The kinetic energy of a fluid increases as it is...Ch. 5.5 - The stators in a gas turbine are designed to...Ch. 5.5 - The diffuser in a jet engine is designed to...Ch. 5.5 - Air enters a nozzle steadily at 50 psia, 140F, and...Ch. 5.5 - Air at 600 kPa and 500 K enters an adiabatic...Ch. 5.5 - Carbon dioxide enters an adiabatic nozzle steadily...Ch. 5.5 - Steam enters a nozzle at 400C and 800 kPa with a...Ch. 5.5 - Air at 80 kPa and 127C enters an adiabatic...Ch. 5.5 - Air at 13 psia and 65F enters an adiabatic...Ch. 5.5 - Refrigerant-134a at 700 kPa and 120C enters an...Ch. 5.5 - Refrigerant-134a enters a diffuser steadily as...Ch. 5.5 - Air at 80 kPa, 27C, and 220 m/s enters a diffuser...Ch. 5.5 - Air enters an adiabatic nozzle steadily at 300...Ch. 5.5 - Consider an adiabatic turbine operating steadily....Ch. 5.5 - Prob. 42PCh. 5.5 - Somebody proposes the following system to cool a...Ch. 5.5 - Air is expanded from 1000 kPa and 600C at the...Ch. 5.5 - Prob. 45PCh. 5.5 - Refrigerant-134a enters a compressor at 100 kPa...Ch. 5.5 - Refrigerant-134a enters a compressor at 180 kPa as...Ch. 5.5 - Steam flows steadily through an adiabatic turbine....Ch. 5.5 - Steam flows steadily through a turbine at a rate...Ch. 5.5 - Steam enters an adiabatic turbine at 8 MPa and...Ch. 5.5 - An adiabatic air compressor compresses 10 L/s of...Ch. 5.5 - Carbon dioxide enters an adiabatic compressor at...Ch. 5.5 - Steam flows steadily into a turbine with a mass...Ch. 5.5 - Air is compressed by an adiabatic compressor from...Ch. 5.5 - Air enters the compressor of a gas-turbine plant...Ch. 5.5 - A portion of the steam passing through a steam...Ch. 5.5 - Why are throttling devices commonly used in...Ch. 5.5 - Would you expect the temperature of air to drop as...Ch. 5.5 - During a throttling process, the temperature of a...Ch. 5.5 - Someone claims, based on temperature measurements,...Ch. 5.5 - Refrigerant-134a is throttled from the saturated...Ch. 5.5 - A saturated liquidvapor mixture of water, called...Ch. 5.5 - Prob. 64PCh. 5.5 - A well-insulated valve is used to throttle steam...Ch. 5.5 - Refrigerant-134a enters the expansion valve of a...Ch. 5.5 - Prob. 68PCh. 5.5 - Prob. 69PCh. 5.5 - Consider a steady-flow heat exchanger involving...Ch. 5.5 - Prob. 71PCh. 5.5 - Refrigerant-134a at 700 kPa, 70C, and 8 kg/min is...Ch. 5.5 - Hot and cold streams of a fluid are mixed in a...Ch. 5.5 - A hot-water stream at 80C enters a mixing chamber...Ch. 5.5 - Water at 80F and 20 psia is heated in a chamber by...Ch. 5.5 - An adiabatic open feedwater heater in an electric...Ch. 5.5 - Cold water (cp = 4.18 kJ/kgC) leading to a shower...Ch. 5.5 - Steam is to be condensed on the shell side of a...Ch. 5.5 - Air (cp = 1.005 kJ/kgC) is to be preheated by hot...Ch. 5.5 - An open feedwater heater heats the feedwater by...Ch. 5.5 - Refrigerant-134a at 1 MPa and 90C is to be cooled...Ch. 5.5 - The evaporator of a refrigeration cycle is...Ch. 5.5 - An air-conditioning system involves the mixing of...Ch. 5.5 - A well-insulated shell-and-tube heat exchanger is...Ch. 5.5 - Steam is to be condensed in the condenser of a...Ch. 5.5 - Steam is to be condensed in the condenser of a...Ch. 5.5 - Two streams of water are mixed in an insulated...Ch. 5.5 - Two mass streams of the same ideal gas are mixed...Ch. 5.5 - Water is heated in an insulated, constant-diameter...Ch. 5.5 - A 110-volt electrical heater is used to warm 0.3...Ch. 5.5 - The ducts of an air heating system pass through an...Ch. 5.5 - The fan on a personal computer draws 0.3 ft3/s of...Ch. 5.5 - Saturated liquid water is heated in a steady-flow...Ch. 5.5 - Water enters the tubes of a cold plate at 70F with...Ch. 5.5 - Prob. 96PCh. 5.5 - A computer cooled by a fan contains eight PCBs,...Ch. 5.5 - A desktop computer is to be cooled by a fan. The...Ch. 5.5 - Prob. 99PCh. 5.5 - A 4-m 5-m 6-m room is to be heated by an...Ch. 5.5 - A house has an electric heating system that...Ch. 5.5 - A long roll of 2-m-wide and 0.5-cm-thick 1-Mn...Ch. 5.5 - Prob. 103PCh. 5.5 - Prob. 104PCh. 5.5 - Argon steadily flows into a constant-pressure...Ch. 5.5 - Steam enters a long, horizontal pipe with an inlet...Ch. 5.5 - Refrigerant-134a enters the condenser of a...Ch. 5.5 - A hair dryer is basically a duct in which a few...Ch. 5.5 - A hair dryer is basically a duct in which a few...Ch. 5.5 - Air enters the duct of an air-conditioning system...Ch. 5.5 - An insulated rigid tank is initially evacuated. A...Ch. 5.5 - A rigid, insulated tank that is initially...Ch. 5.5 - Prob. 115PCh. 5.5 - A 2-m3 rigid tank initially contains air at 100...Ch. 5.5 - A 0.2-m3 rigid tank equipped with a pressure...Ch. 5.5 - Prob. 118PCh. 5.5 - An insulated 40-ft3 rigid tank contains air at 50...Ch. 5.5 - A 4-L pressure cooker has an operating pressure of...Ch. 5.5 - An air-conditioning system is to be filled from a...Ch. 5.5 - Oxygen is supplied to a medical facility from ten...Ch. 5.5 - A 0.05-m3 rigid tank initially contains...Ch. 5.5 - A 0.12-m3 rigid tank contains saturated...Ch. 5.5 - A 0.3-m3 rigid tank is filled with saturated...Ch. 5.5 - The air-release flap on a hot-air balloon is used...Ch. 5.5 - Prob. 127PCh. 5.5 - An insulated 0.15-m3 tank contains helium at 3 MPa...Ch. 5.5 - A vertical pistoncylinder device initially...Ch. 5.5 - A vertical piston-cylinder device initially...Ch. 5.5 - A pistoncylinder device initially contains 0.6 kg...Ch. 5.5 - The weighted piston of the device shown in Fig....Ch. 5.5 - Prob. 136RPCh. 5.5 - Prob. 137RPCh. 5.5 - Prob. 138RPCh. 5.5 - Air at 4.18 kg/m3 enters a nozzle that has an...Ch. 5.5 - Prob. 140RPCh. 5.5 - An air compressor compresses 15 L/s of air at 120...Ch. 5.5 - A steam turbine operates with 1.6 MPa and 350C...Ch. 5.5 - Refrigerant-134a enters an adiabatic compressor at...Ch. 5.5 - Prob. 144RPCh. 5.5 - Prob. 145RPCh. 5.5 - Prob. 146RPCh. 5.5 - Prob. 147RPCh. 5.5 - Steam enters a nozzle with a low velocity at 150C...Ch. 5.5 - Prob. 149RPCh. 5.5 - Prob. 150RPCh. 5.5 - Prob. 151RPCh. 5.5 - Prob. 152RPCh. 5.5 - Prob. 153RPCh. 5.5 - Cold water enters a steam generator at 20C and...Ch. 5.5 - An ideal gas expands in an adiabatic turbine from...Ch. 5.5 - Determine the power input for a compressor that...Ch. 5.5 - Prob. 157RPCh. 5.5 - Prob. 158RPCh. 5.5 - Prob. 159RPCh. 5.5 - Prob. 160RPCh. 5.5 - In a dairy plant, milk at 4C is pasteurized...Ch. 5.5 - Prob. 162RPCh. 5.5 - Prob. 163RPCh. 5.5 - Prob. 164RPCh. 5.5 - Prob. 165RPCh. 5.5 - Prob. 166RPCh. 5.5 - The average atmospheric pressure in Spokane,...Ch. 5.5 - The ventilating fan of the bathroom of a building...Ch. 5.5 - Prob. 169RPCh. 5.5 - Determine the rate of sensible heat loss from a...Ch. 5.5 - Prob. 171RPCh. 5.5 - An air-conditioning system requires airflow at the...Ch. 5.5 - A building with an internal volume of 400 m3 is to...Ch. 5.5 - The maximum flow rate of standard shower heads is...Ch. 5.5 - Prob. 176RPCh. 5.5 - Prob. 177RPCh. 5.5 - Steam enters a turbine steadily at 7 MPa and 600C...Ch. 5.5 - Reconsider Prob. 5178. Using appropriate software,...Ch. 5.5 - Prob. 180RPCh. 5.5 - A liquid R-134a bottle has an internal volume of...Ch. 5.5 - A pistoncylinder device initially contains 2 kg of...Ch. 5.5 - A pistoncylinder device initially contains 1.2 kg...Ch. 5.5 - A pressure cooker is a pot that cooks food much...Ch. 5.5 - A tank with an internal volume of 1 m3 contains...Ch. 5.5 - In a single-flash geothermal power plant,...Ch. 5.5 - An adiabatic air compressor is to be powered by a...Ch. 5.5 - The turbocharger of an internal combustion engine...Ch. 5.5 - Prob. 189RPCh. 5.5 - Consider an evacuated rigid bottle of volume V...Ch. 5.5 - An adiabatic heat exchanger is used to heat cold...Ch. 5.5 - A heat exchanger is used to heat cold water at 15C...Ch. 5.5 - An adiabatic heat exchanger is used to heat cold...Ch. 5.5 - In a shower, cold water at 10C flowing at a rate...Ch. 5.5 - Prob. 195FEPCh. 5.5 - Prob. 196FEPCh. 5.5 - Hot combustion gases (assumed to have the...Ch. 5.5 - Steam expands in a turbine from 4 MPa and 500C to...Ch. 5.5 - Steam is compressed by an adiabatic compressor...Ch. 5.5 - Refrigerant-134a is compressed by a compressor...Ch. 5.5 - Refrigerant-134a at 1.4 MPa and 70C is throttled...Ch. 5.5 - Prob. 202FEPCh. 5.5 - Prob. 203FEPCh. 5.5 - Air at 27C and 5 atm is throttled by a valve to 1...Ch. 5.5 - Steam at 1 MPa and 300C is throttled adiabatically...Ch. 5.5 - Air is to be heated steadily by an 8-kW electric...Ch. 5.5 - Saturated water vapor at 40C is to be condensed as...
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
- The catalogue for a refrigerant 22, four-cylinder, hermetic compressor operating at 29 r/s. a condensing temperature of 40 °C and an evaporating temperature of -4 °C shows a refrigeration capacity of 96.4 kW. At this operating points the motor (whose efficiency is 90 percent) draws 28.9 kW. The bore of the cylinders is 87 mm and the piston stroke is 70 mm. The performance data are based on 8 °C of subcooling of the liquid leaving the condenser. Compute 3.1 the actual volumetric efficiency and 3.2 the compression efficiency.arrow_forwardA vapour compression refrigerator circulates 4.5 kg of NH3 per hour. Condensation take place at 30°C and evaporation at – 15°C. There is no under-cooling of the refrigerant. The temperature after isentropic compression is 75°C and specific heat of superheated vapour is 2.82 kJ/kg K. Determine : (i) Co-efficient of performance. (ii) Ice produced in kg per hour in the evaporator from water at 20°C and ice at 0°C. Take : Enthalpy of fusion of ice = 336 kJ/kg, specific heat of water = 4.187 kJ/kg. (iii) The effective swept volume of the compressor in m3 /min.arrow_forwardA refrigerator with tetrafluoroethane as refrigerant operates with an evaporation temperature of −25°C and a condensation temperature of 26°C. Saturated liquid refrigerant from the condenser flows through an expansion valve into the evaporator, from which it emerges as saturated vapor. (a) For a cooling rate of 5 kJ·s−1, what is the circulation rate of the refrigerant? (b) By how much would the circulation rate be reduced if the throttle valve were replaced by a turbine in which the refrigerant expands isentropically?arrow_forward
- Explain the thermodynamic processes involved in a multi-stage compression system, outlining the specific efficiency considerations at each stage, and how these processes differ from a single-stage compression system.arrow_forwardExhaust steam from an engine passes into a condenser at a pressure of 0.12 bar and dryness 0.88. The temperature of the condensate from the condenser is 40°C. The circulating water enters the condenser at 12°C and leaves at 29°C. Calculate the mass of circulating water per kg steam condensed. Steam Properties: Steam at 0.12 bar (0.012 MPa) hf = 207 kJ/kg hfg = 2383 kJ/kg Water Properties Water at 40°C Water at 29°C Water at 12°C h = 167.5 kJ/kg h = 121.5 kJ/kg h = 50.4 kJ/kg A. 26.71 kg B. 28.05 kg C. 30.04 kg D. 32.86 kgarrow_forwardIt is suggested to pump 5,000 kg/h of a liquid at 114°C and 1.1 atm abs pressure from a reboiler of a distillation tower to a second distillation unit without cooling the liquid before this joins the pump in a given industrial operation. The liquid has a density of 866 kg/ m2 and a vapor pressure of 1.1 atm at this heat.condition. The reboiler-to-pump line has a friction loss of 5 kN/m2. a. To achieve a net positive suction head of 2.5 m, how far must the liquid level in the reboiler be maintained? b. Compute the power needed to drive the pump if the liquid is to be elevated 5 meters, the pressure in the second unit is atmospheri and the discharge line friction loss is 25 kN/ m2. The pump discharge line has a velocity of 2 m/s, and the pump-motor efficiency is 65 percent.arrow_forward
- 2. A refrigeration system using R-12 is to have a refrigerating capacity of 60 kW. The evaporating temperature is 10°C and the condensing temperature is 42°C. Determine (a) the volume flow rate of refrigerant at inlet to the compressor, (b) the power required by the compressor, and (c) the fraction of vapor mixture at entrance to the evaporator expressed both on a mass basis and volume basis.arrow_forwardHow is the process of refrigeration explained in terms of the First Law of Thermodynamics.arrow_forwardMoist air enters an air-conditioning system as shown in the figure below at T1 = 28°C, 01 = 80% and a volumetric flow rate of (AV)1 = 0.47 m3/s. At the exit of the dehumidifying section, the air is saturated, @, = 100%, and the condensate leaves this section at the same temperature as the moist air. At the exit of the heating section the moist air is at T3 = 24°C, 03 = 50%. The system operates at steady state, the pressure is 1 bar at all locations, and kinetic and potential energy effects are negligible. Dehumidifying Section Heating Section 2 = 100% T3 = 24°C Ø3 = 50% T1= 28°C $1. (AV)ı Initial dew point- O = 100% Condensate - saturated at T2 T2 T3 wwarrow_forward
- السؤال الثالث The thermodynamic properties of refrigerant R22 mixture of liquid and vapor leaving the expansion device and entering the evaporator are: pressure of 498 KPa, temperature of 0 °C, fraction dryness (x) of 0.238, saturated liquid enthalpy of 200 kJ/kg, and saturated vapour enthalpy of 405 kJ/kg. The pressure of this refrigerant at the entrance of the condenser is measured to be 19.3 bar After the subcooling process, the enthalpy in (kJ/kg) and the pressure in (MPa) of this refrigerant have been measured and were found to be 199 47 kJ/kg and 2.3 MPa. 239. 68 kJ/kg and 1.96 MPAO 248.79 kU/kg and 1.93 MPa 110 52 kJ/kg and 3.1 MPa 1:29 PM 91°F Sunny 5/14/2022arrow_forwardWhy is it important to clean the condenser coils of a household refrigerator a few times a year? Also, why is it important not to block airflow through the condenser coils?arrow_forwardExplain using the concept of Ideal gas laws on how do you make a cold body, and how air conditioners and refrigerators work.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 PressMechanics of Materials (10th Edition)Mechanical EngineeringISBN:9780134319650Author:Russell C. HibbelerPublisher:PEARSONThermodynamics: An Engineering ApproachMechanical EngineeringISBN:9781259822674Author:Yunus A. Cengel Dr., Michael A. BolesPublisher:McGraw-Hill Education
- Control Systems EngineeringMechanical EngineeringISBN:9781118170519Author:Norman S. NisePublisher:WILEYMechanics of Materials (MindTap Course List)Mechanical EngineeringISBN:9781337093347Author:Barry J. Goodno, James M. GerePublisher:Cengage LearningEngineering 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