Thermodynamics: An Engineering Approach
9th Edition
ISBN: 9781260048766
Author: CENGEL
Publisher: MCG
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 14.7, Problem 147FEP
Air at a total pressure of 90 kPa, 15°C, and 75 percent relative humidity is heated and humidified to 25°C and 75 percent relative humidity by introducing water vapor. If the mass flow rate of dry air is 4 kg/s, the rate at which steam is added to the air is
- (a) 0.032 kg/s
- (b) 0.013 kg/s
- (c) 0.019 kg/s
- (d) 0.0079 kg/s
- (e) 0 kg/s
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Air enters a cooling tower at a rate of 1100 cubic meters per minute, at 15°C and
65% relative humidity. Atmospheric pressure is 100 kPa. Water enters the tower at
38°C and leaves at 17°C. Air leaves the tower at 31°C and saturated. Using a
psychrometric chart calculate the absolute humidity of the air leaving the cooling
tower.
0.029 kg water vapour/kg air
0.069 kg water vapour/kg air
O 0.0101 kg water vapour/kg air
0.364 kg water vapour/kg air
The air in a room (24.0°C and 30% humidity) with a volume of 96.6 m3 must be replaced every 5 minutes. Outside air at 38.0°C and 70% humidity is chilled to remove some of its water content and then dehumidified to the required temperature. What is the volumetric flow rate (in m3/min) of the humid air entering the chiller?
Fresh atmospheric air mixed with recycled air is heated to 349K and admitted to a drier at 101.3 KPa at a rate of 100 m3/min. The relative humidity of the air entering the drier is 7.5%. Atmospheric air is at 302K and has a relative humidity of 30%. The air leaves the drier at 306K and 90% relative humidity, a portion of which is recycled and the other portion discarded. The vapour pressures of water are 4KPa at 302K, 5KPa at 306K and 40KPa at 349K. Calculate the following:a) The ratio of wet recycle stream to wet fresh stream.b) The mass of dry air to be fed to the drier to remove one kilogram of water in the drier.c) The rate at which water is removed in kg/min.
Chapter 14 Solutions
Thermodynamics: An Engineering Approach
Ch. 14.7 - What is the difference between dry air and...Ch. 14.7 - What is vapor pressure?Ch. 14.7 - What is the difference between the specific...Ch. 14.7 - Can the water vapor in air be treated as an ideal...Ch. 14.7 - Explain how vapor pressure of the ambient air is...Ch. 14.7 - Is the relative humidity of saturated air...Ch. 14.7 - Moist air is passed through a cooling section...Ch. 14.7 - How will (a) the specific humidity and (b) the...Ch. 14.7 - Prob. 9PCh. 14.7 - Consider a tank that contains moist air at 3 atm...
Ch. 14.7 - Is it possible to obtain saturated air from...Ch. 14.7 - Why are the chilled water lines always wrapped...Ch. 14.7 - How would you compare the enthalpy of water vapor...Ch. 14.7 - A tank contains 15 kg of dry air and 0.17 kg of...Ch. 14.7 - Prob. 15PCh. 14.7 - An 8-m3 tank contains saturated air at 30C, 105...Ch. 14.7 - Determine the masses of dry air and the water...Ch. 14.7 - A room contains air at 85F and 13.5 psia at a...Ch. 14.7 - Prob. 19PCh. 14.7 - Prob. 20PCh. 14.7 - Prob. 21PCh. 14.7 - In summer, the outer surface of a glass filled...Ch. 14.7 - In some climates, cleaning the ice off the...Ch. 14.7 - Andy and Wendy both wear glasses. On a cold winter...Ch. 14.7 - Prob. 25PCh. 14.7 - Prob. 26PCh. 14.7 - Prob. 27PCh. 14.7 - A thirsty woman opens the refrigerator and picks...Ch. 14.7 - The air in a room has a dry-bulb temperature of...Ch. 14.7 - Prob. 31PCh. 14.7 - Prob. 32PCh. 14.7 - Prob. 33PCh. 14.7 - How do constant-enthalpy and...Ch. 14.7 - At what states on the psychrometric chart are the...Ch. 14.7 - How is the dew-point temperature at a specified...Ch. 14.7 - Can the enthalpy values determined from a...Ch. 14.7 - Atmospheric air at a pressure of 1 atm and...Ch. 14.7 - Prob. 39PCh. 14.7 - Prob. 40PCh. 14.7 - Prob. 41PCh. 14.7 - Atmospheric air at a pressure of 1 atm and...Ch. 14.7 - Reconsider Prob. 1443. Determine the adiabatic...Ch. 14.7 - What does a modern air-conditioning system do...Ch. 14.7 - How does the human body respond to (a) hot...Ch. 14.7 - How does the air motion in the vicinity of the...Ch. 14.7 - Consider a tennis match in cold weather where both...Ch. 14.7 - Prob. 49PCh. 14.7 - Prob. 50PCh. 14.7 - Prob. 51PCh. 14.7 - Prob. 52PCh. 14.7 - What is metabolism? What is the range of metabolic...Ch. 14.7 - Why is the metabolic rate of women, in general,...Ch. 14.7 - What is sensible heat? How is the sensible heat...Ch. 14.7 - Prob. 56PCh. 14.7 - Prob. 57PCh. 14.7 - Prob. 58PCh. 14.7 - Prob. 59PCh. 14.7 - Repeat Prob. 1459 for an infiltration rate of 1.8...Ch. 14.7 - An average (1.82 kg or 4.0 lbm) chicken has a...Ch. 14.7 - An average person produces 0.25 kg of moisture...Ch. 14.7 - How do relative and specific humidities change...Ch. 14.7 - Prob. 64PCh. 14.7 - Humid air at 150 kPa, 40C, and 70 percent relative...Ch. 14.7 - Humid air at 40 psia, 50F, and 90 percent relative...Ch. 14.7 - Prob. 67PCh. 14.7 - Air enters a 30-cm-diameter cooling section at 1...Ch. 14.7 - Prob. 69PCh. 14.7 - Prob. 70PCh. 14.7 - Why is heated air sometimes humidified?Ch. 14.7 - Air at 1 atm, 15C, and 60 percent relative...Ch. 14.7 - Air at 14.7 psia, 35F, and 50 percent relative...Ch. 14.7 - An air-conditioning system operates at a total...Ch. 14.7 - Prob. 75PCh. 14.7 - Why is cooled air sometimes reheated in summer...Ch. 14.7 - Atmospheric air at 1 atm, 30C, and 80 percent...Ch. 14.7 - Ten thousand cubic feet per hour of atmospheric...Ch. 14.7 - Air enters a 40-cm-diameter cooling section at 1...Ch. 14.7 - Repeat Prob. 1479 for a total pressure of 88 kPa...Ch. 14.7 - On a summer day in New Orleans, Louisiana, the...Ch. 14.7 - Prob. 83PCh. 14.7 - Prob. 84PCh. 14.7 - Prob. 85PCh. 14.7 - Saturated humid air at 70 psia and 200F is cooled...Ch. 14.7 - Humid air is to be conditioned in a...Ch. 14.7 - Atmospheric air at 1 atm, 32C, and 95 percent...Ch. 14.7 - Prob. 89PCh. 14.7 - Prob. 90PCh. 14.7 - Does an evaporation process have to involve heat...Ch. 14.7 - Prob. 92PCh. 14.7 - Prob. 93PCh. 14.7 - Air enters an evaporative (or swamp) cooler at...Ch. 14.7 - Prob. 95PCh. 14.7 - Air at 1 atm, 20C, and 70 percent relative...Ch. 14.7 - Two unsaturated airstreams are mixed...Ch. 14.7 - Consider the adiabatic mixing of two airstreams....Ch. 14.7 - Two airstreams are mixed steadily and...Ch. 14.7 - A stream of warm air with a dry-bulb temperature...Ch. 14.7 - Prob. 104PCh. 14.7 - Prob. 105PCh. 14.7 - How does a natural-draft wet cooling tower work?Ch. 14.7 - What is a spray pond? How does its performance...Ch. 14.7 - The cooling water from the condenser of a power...Ch. 14.7 - A wet cooling tower is to cool 60 kg/s of water...Ch. 14.7 - Prob. 110PCh. 14.7 - Prob. 111PCh. 14.7 - Water at 30C is to be cooled to 22C in a cooling...Ch. 14.7 - Prob. 113PCh. 14.7 - Prob. 114RPCh. 14.7 - Determine the mole fraction of dry air at the...Ch. 14.7 - Prob. 116RPCh. 14.7 - Prob. 117RPCh. 14.7 - Prob. 118RPCh. 14.7 - Prob. 119RPCh. 14.7 - Prob. 120RPCh. 14.7 - Prob. 121RPCh. 14.7 - Prob. 122RPCh. 14.7 - Prob. 124RPCh. 14.7 - Prob. 125RPCh. 14.7 - Prob. 126RPCh. 14.7 - Prob. 128RPCh. 14.7 - Prob. 129RPCh. 14.7 - Air enters a cooling section at 97 kPa, 35C, and...Ch. 14.7 - Prob. 131RPCh. 14.7 - Atmospheric air enters an air-conditioning system...Ch. 14.7 - Humid air at 101.3 kPa, 36C dry bulb and 65...Ch. 14.7 - An automobile air conditioner uses...Ch. 14.7 - Prob. 135RPCh. 14.7 - Prob. 137RPCh. 14.7 - Conditioned air at 13C and 90 percent relative...Ch. 14.7 - Prob. 141FEPCh. 14.7 - A 40-m3 room contains air at 30C and a total...Ch. 14.7 - A room is filled with saturated moist air at 25C...Ch. 14.7 - Prob. 144FEPCh. 14.7 - The air in a house is at 25C and 65 percent...Ch. 14.7 - Prob. 146FEPCh. 14.7 - Air at a total pressure of 90 kPa, 15C, and 75...Ch. 14.7 - On the psychrometric chart, a cooling and...Ch. 14.7 - On the psychrometric chart, a heating and...Ch. 14.7 - An airstream at a specified temperature and...
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
- Conditioned air at 13°C and 90 percent relative humidity is to be mixed with outside air at 34°C and 40 percent relative humidity at 1 atm. If it is desired that the mixture has a relative humidity of 60 percent, determine (a) the ratio of the dry air mass flow rates of the conditioned air to the outside air, (b) the temperature of the mixture, and (c) check your results by the psychrometric chart. Note: do not use the psychrometric chart for calculation.arrow_forwardAn air-conditioning system operates at a total pressure of 1 atm and consists of a heating section and anevaporative cooler. Air enters the heating section at 14°C and 60 percent relative humidity at a rate of 30m3/min, and it leaves the evaporative cooler at 25°C and 45 percent relatively humidity. Determine (a) thetemperature and relative humidity of the air when it leaves the heating section, (b) the rate of heat transfer in theheating section, and (c) the rate of water added to air in the evaporative cooler.arrow_forwardMoist air flowing at 2 kg/s and a dry bulb temperature of 50 C and wet bulb temperature of 30C mixes with another stream of moist air flowing at 3 kg/s at 25C and relative humidity of 65%. Using a psychrometric chart, determine the (a) humidity ratio, (b) enthalpy, and (c) dry bulb temperature of the two streams mixed together.arrow_forward
- An air-conditioning system operates at a total pressure of 1 atm and consists of a heating section and an evaporative cooler. Air enters the heating section at 12°C and 50 percent relative humidity at a rate of 20 m³/min, and it leaves the evaporative cooler at 25°C and 40 percent relatively humidity. Determine (a) the temperature and relative humidity of the air when it leaves the heating section, (b) the rate of heat transfer in the heating section, and (c) the rate of water added to air in the evaporative cooler.arrow_forwardCooling water leaves the condenser of a power plant and enters a wet cooling tower at 35°C at a rate of 100 kg/s. Water is cooled to 22°C in the cooling tower by air that enters the tower at 1 atm, 20°C, and 60 percent relative humidity and leaves saturated at 30°C. Neglecting the power input to the fan, determine (a) the volume flow rate of air into the cooling tower and (b) the mass flow rate of the required makeup water.arrow_forwardA tank contains 22 kg of dry air and 0.2 kg of water vapor at 30 °C and 91 kPa total pressure. Determine (1) the specific humidity. (2) the relative humidity. (3) the volume of the tank.arrow_forward
- Air enters a 50-cm-diameter cooling section at 100 kPa, 35°C, and 30 percent relative humidity at 20 m/s. Heat is removed from the air at a rate of 1500 kJ/min. Determine (a) the exit temperature, (b) the exit relative humidity of the air, and (c) the exit velocity. 1500 kJ/min 35°C 30% RH AIR 20 m/s 100 kPaarrow_forwardAir at 30 ºC with a dew point of 14ºC enters a textile dryer at a rate of 15.3 m3/min and leaves saturated. The dryer operates adiabatically. Use the psychrometric chart to determine the absolute humidity and humid volume of the entering air, and then use the results to determine the flow rate of dry air (kg/min) through the dryer, thefinal temperature of the air, and the rate (kg/min) at which water is evaporated in the dryer.arrow_forwardAir enters a heating section at 95 kPa, 10°C, and 30 percent relative humidity at a rate of 6.2 m3/min, and it leaves at 25 C Use data from the tables. Determine the rate of heat transfer in the heating section The rate of heat transfer is [ kJ/minarrow_forward
- A drier is to be designed to reduce the water content of a certain material from 55% to 10%. Air at 29 C dry bulb temperature and with a humidity ratio of 0.005 kg/kg is heated to 50 C in a reheater before entering the drier. The air leaves the drier at 38 C with 70% relative humidity. On the basis of 1000 kg of product per hour, calculate (a) the volume flow rate of air entering the reheater, and (b) the heat supplied in the reheater.arrow_forwardThe dry- and wet-bulb temperatures of atmospheric air at 95 kPa are 25 and 17°C, respectively. Determine (a) the specific humidity (b) the relative humidity and (c) the enthalpy of the 9 air, in kJ/kg dry airarrow_forwardTwo airstreams are mixed steadily and adiabatically. The first stream enters at 35°C and 30 percent relative humidity at a rate of 15 m/min, while the second stream enters at 12°C and 90 percent relative humidity at a rate of 23.5 m/min. Assuming that the mixing process occurs at a pressure of 90 kPa, determine the specific humidity, the relative humidity, the dry-bulb temperature, and the volume flow rate of the mixture. Use data from the tables. 35°C 30% P-90 kPa Air 12°C 90% The specific humidity is kg H20/kg dry air. The relative humidity is %. The dry-bulb temperature is 1°C. m3/min. The volume flow rate of the mixture isarrow_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
First Law of Thermodynamics, Basic Introduction - Internal Energy, Heat and Work - Chemistry; Author: The Organic Chemistry Tutor;https://www.youtube.com/watch?v=NyOYW07-L5g;License: Standard youtube license