Thermodynamics: An Engineering Approach
9th Edition
ISBN: 9781259822674
Author: Yunus A. Cengel Dr., Michael A. Boles
Publisher: McGraw-Hill Education
expand_more
expand_more
format_list_bulleted
Question
Chapter 8.8, Problem 93RP
a)
To determine
The rate of steam production
b)
To determine
The exergy destruction in the heat exchanger
c)
To determine
The second law efficiency for heat exchanger
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solutionStudents have asked these similar questions
Hot combustion gases enter the nozzle of a turbojet engine at 250 kPa, 650°C, and 70 m/s and exit at
80 kPa and 420°C. The mass flow rate is 1.2 kg/s. Assume the heat losses to the surroundings is 90kW
and the surroundings is at 27°C. Determine (a) the exit velocity and (b) the decrease in the exergy of
the gases. Take k = 1.3 and c, = 1.15 kJkg-°C for the combustion gases.
Qtoss = 90kW
250 kPa
Combustion
gases
80 kPa
650°C
420°C
70 m/s
m = 1.2 kg/s
m = 1.2 kg/s
1.
The heat produced in a boiler is transferred from the combustion products to the water. While the temperature of the combustion products decreases from 1100 °C to 550 °C, the pressure remains constant at 0.1 MPa. The average specific heat at constant pressure of the combustion products is 1.09 kJ/kg.K. The water enters the system at 0.8 MPa and 150 °C, and leaves at 0.8 MPa and 250 °C. Determine the second law efficiency and the irreversibility for each kilogram of water vaporized for this process.
Note: This is a thermodynamics course question.
Please provide a solution that is clear and quick.
A well-insulated heat exchanger is to heat water(cp = 4.18 kJ/kg8C) from 25 to 60C at a rate of 0.50 kg/s. The heating is to be accomplished by geothermal water(cp = 4.31 kJ/kg8C) available at 140C at a mass flow rate of0.75 kg/s. Determine (a) the rate of heat transfer and (b) therate of entropy generation in the heat exchanger.
Chapter 8 Solutions
Thermodynamics: An Engineering Approach
Ch. 8.8 - What final state will maximize the work output of...Ch. 8.8 - Is the exergy of a system different in different...Ch. 8.8 - Under what conditions does the reversible work...Ch. 8.8 - How does useful work differ from actual work? For...Ch. 8.8 - How does reversible work differ from useful work?Ch. 8.8 - Is a process during which no entropy is generated...Ch. 8.8 - Consider an environment of zero absolute pressure...Ch. 8.8 - It is well known that the actual work between the...Ch. 8.8 - Consider two geothermal wells whose energy...Ch. 8.8 - Consider two systems that are at the same pressure...
Ch. 8.8 - Prob. 11PCh. 8.8 - Does a power plant that has a higher thermal...Ch. 8.8 - Prob. 13PCh. 8.8 - Saturated steam is generated in a boiler by...Ch. 8.8 - One method of meeting the extra electric power...Ch. 8.8 - A heat engine that receives heat from a furnace at...Ch. 8.8 - Consider a thermal energy reservoir at 1500 K that...Ch. 8.8 - A heat engine receives heat from a source at 1100...Ch. 8.8 - A heat engine that rejects waste heat to a sink at...Ch. 8.8 - A geothermal power plant uses geothermal liquid...Ch. 8.8 - A house that is losing heat at a rate of 35,000...Ch. 8.8 - A freezer is maintained at 20F by removing heat...Ch. 8.8 - Prob. 24PCh. 8.8 - Prob. 25PCh. 8.8 - Prob. 26PCh. 8.8 - Can a system have a higher second-law efficiency...Ch. 8.8 - A mass of 8 kg of helium undergoes a process from...Ch. 8.8 - Which is a more valuable resource for work...Ch. 8.8 - Which has the capability to produce the most work...Ch. 8.8 - The radiator of a steam heating system has a...Ch. 8.8 - A well-insulated rigid tank contains 6 lbm of a...Ch. 8.8 - A pistoncylinder device contains 8 kg of...Ch. 8.8 - Prob. 35PCh. 8.8 - Prob. 36PCh. 8.8 - Prob. 37PCh. 8.8 - A pistoncylinder device initially contains 2 L of...Ch. 8.8 - A 0.8-m3 insulated rigid tank contains 1.54 kg of...Ch. 8.8 - An insulated pistoncylinder device initially...Ch. 8.8 - Prob. 41PCh. 8.8 - An insulated rigid tank is divided into two equal...Ch. 8.8 - A 50-kg iron block and a 20-kg copper block, both...Ch. 8.8 - Prob. 45PCh. 8.8 - Prob. 46PCh. 8.8 - Prob. 47PCh. 8.8 - A pistoncylinder device initially contains 1.4 kg...Ch. 8.8 - Prob. 49PCh. 8.8 - Prob. 50PCh. 8.8 - Prob. 51PCh. 8.8 - Air enters a nozzle steadily at 200 kPa and 65C...Ch. 8.8 - Prob. 54PCh. 8.8 - Prob. 55PCh. 8.8 - Argon gas enters an adiabatic compressor at 120...Ch. 8.8 - Prob. 57PCh. 8.8 - Prob. 58PCh. 8.8 - The adiabatic compressor of a refrigeration system...Ch. 8.8 - Refrigerant-134a at 140 kPa and 10C is compressed...Ch. 8.8 - Air enters a compressor at ambient conditions of...Ch. 8.8 - Combustion gases enter a gas turbine at 900C, 800...Ch. 8.8 - Steam enters a turbine at 9 MPa, 600C, and 60 m/s...Ch. 8.8 - Refrigerant-134a is condensed in a refrigeration...Ch. 8.8 - Prob. 66PCh. 8.8 - Refrigerant-22 absorbs heat from a cooled space at...Ch. 8.8 - Prob. 68PCh. 8.8 - Prob. 69PCh. 8.8 - Air enters a compressor at ambient conditions of...Ch. 8.8 - Hot combustion gases enter the nozzle of a...Ch. 8.8 - Prob. 72PCh. 8.8 - A 0.6-m3 rigid tank is filled with saturated...Ch. 8.8 - Prob. 74PCh. 8.8 - Prob. 75PCh. 8.8 - An insulated vertical pistoncylinder device...Ch. 8.8 - Liquid water at 200 kPa and 15C is heated in a...Ch. 8.8 - Prob. 78PCh. 8.8 - Prob. 79PCh. 8.8 - A well-insulated shell-and-tube heat exchanger is...Ch. 8.8 - Steam is to be condensed on the shell side of a...Ch. 8.8 - Prob. 82PCh. 8.8 - Prob. 83PCh. 8.8 - Prob. 84PCh. 8.8 - Prob. 85RPCh. 8.8 - Prob. 86RPCh. 8.8 - An aluminum pan has a flat bottom whose diameter...Ch. 8.8 - Prob. 88RPCh. 8.8 - Prob. 89RPCh. 8.8 - A well-insulated, thin-walled, counterflow heat...Ch. 8.8 - Prob. 92RPCh. 8.8 - Prob. 93RPCh. 8.8 - Prob. 94RPCh. 8.8 - Prob. 95RPCh. 8.8 - Nitrogen gas enters a diffuser at 100 kPa and 110C...Ch. 8.8 - Prob. 97RPCh. 8.8 - Steam enters an adiabatic nozzle at 3.5 MPa and...Ch. 8.8 - Prob. 99RPCh. 8.8 - A pistoncylinder device initially contains 8 ft3...Ch. 8.8 - An adiabatic turbine operates with air entering at...Ch. 8.8 - Steam at 7 MPa and 400C enters a two-stage...Ch. 8.8 - Prob. 103RPCh. 8.8 - Steam enters a two-stage adiabatic turbine at 8...Ch. 8.8 - Prob. 105RPCh. 8.8 - Prob. 106RPCh. 8.8 - Prob. 107RPCh. 8.8 - Prob. 108RPCh. 8.8 - Prob. 109RPCh. 8.8 - Prob. 111RPCh. 8.8 - A passive solar house that was losing heat to the...Ch. 8.8 - Prob. 113RPCh. 8.8 - A 4-L pressure cooker has an operating pressure of...Ch. 8.8 - Repeat Prob. 8114 if heat were supplied to the...Ch. 8.8 - Prob. 116RPCh. 8.8 - A rigid 50-L nitrogen cylinder is equipped with a...Ch. 8.8 - Prob. 118RPCh. 8.8 - Prob. 119RPCh. 8.8 - Prob. 120RPCh. 8.8 - Reconsider Prob. 8-120. The air stored in the tank...Ch. 8.8 - Prob. 122RPCh. 8.8 - Prob. 123RPCh. 8.8 - Prob. 124RPCh. 8.8 - Prob. 125RPCh. 8.8 - Prob. 126RPCh. 8.8 - Prob. 127RPCh. 8.8 - Water enters a pump at 100 kPa and 30C at a rate...Ch. 8.8 - Prob. 129RPCh. 8.8 - Prob. 130RPCh. 8.8 - Obtain a relation for the second-law efficiency of...Ch. 8.8 - Writing the first- and second-law relations and...Ch. 8.8 - Prob. 133RPCh. 8.8 - Keeping the limitations imposed by the second law...Ch. 8.8 - Prob. 135FEPCh. 8.8 - Prob. 136FEPCh. 8.8 - Prob. 137FEPCh. 8.8 - Prob. 138FEPCh. 8.8 - A furnace can supply heat steadily at 1300 K at a...Ch. 8.8 - A heat engine receives heat from a source at 1500...Ch. 8.8 - Air is throttled from 50C and 800 kPa to a...Ch. 8.8 - Prob. 142FEPCh. 8.8 - A 12-kg solid whose specific heat is 2.8 kJ/kgC is...
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) Air enters an adiabatic heat exchanger (HX) with a mass flow rate of 850 kg/s at T₁ = 350°C and P₁ = 110kPa and leaves at T₂ = 60°C and P₂ = 100kPa and transfers heat to water which enters the HX as a saturated liquid at 16MPa. The water mass flow rate is 160 kg/s and it leaves the HX at 15MPa. Air has a constant specific heat of Cp = 1.013 kJ/kg . K and specific heat ratio of k = 1.395. Calculate b) the exergy destruction rate of the HX, in MW if the dead state temperature is T₂ = 20°C. To Hot stream + w ww 3 84 Cold streamarrow_forward1) Air enters an adiabatic heat exchanger (HX) with a mass flow rate of 850 kg/s at T₁ = 350°C and P₁ = 110kPa and leaves at T₂ = 60°C and P₂ = 100kPa and transfers heat to water which enters the HX as a saturated liquid at 16MPa. The water mass flow rate is 160 kg/s and it leaves the HX at 15MPa. Air has a constant specific heat of cp = 1.013 kJ/kg . K and specific heat ratio of k = 1.395. Calculate a) the temperature of water at state 4 Hot+ stream + To www ww 3 4 Cold streamarrow_forwardSteam enters the condenser of a steam power plant at 30 kPa, a quality of 91 % and a mass flow rate (m) of 337 kg/min . It leaves the condenser as saturated liquid at 30 kPa. It is to be cooled with water from a nearby river by circulating the water through the tubes within the condenser. To prevent thermal pollution, the river water is not allowed to be heated to a temperature above 5°C. Part A Determine the mass flow rate (m) of the cooling water. Express your answer to the nearest integer. Vol AEo In vec kg/min Submit Request Answer Part B Determine the entropy generation rate (Sgen) in the heat exchanger. Express your answer to three significant figures. vec ? kW/K Submit Request Answer 國arrow_forward
- Refrigerant 134a enters an air-cooled condenser at 12 bars and 60°C, and leaves as a saturated liquid at 12 bars. Atmospheric air at 35°C is blown over the condenser tubes and leaves at 45°C. The heat transfer between the two fluid streams equals 25 MJ/h. Changes in kinetic and potential energy are negligible. Make any reasonable assumptions if necessary. Determine (a) the mass flow rates for the R-134a and the air, in kg/h, Hint: Use the energy conservation on each of the { uid streams separately. (b) the entropy production rate in the condenser, in kJ h-'K-1, Hint: Use the entropy balance over the whole condenser. (c) the change in kinetic energy for R-134a if the pipe diameter is 2.0 cm, in kJ/h (d) Draw the T-s diagram for the process for R-134a. Air P=1 atm T3= 35°C %3! Ref rant 134a R-134a P = 12 bar 2 T = 60°C R-134a P2 = 12 bar Air 4- T4= 45°Carrow_forwardConsider the conditions of Problem 1, homework 5 (it is repeated below) and that the surroundings are at a temperature of 4 C. Instead of mixing the two fluids together consider the following proposal. Heat is allowed to flow from the 3 Kg mass of water through a Carnot heat engine and is rejected to the cooler mass which acts as the low temperature thermal reservoir. Determine the maximum amount of work that could be performed by the heat engine, the entropy produced, and the exergy destroyed in the 3 Kg mass during this operation. Also, determine the total entropy produced and exergy destroyed in the total system. In this case the temperature and internal energy of the mass of water is changing unlike the infinite heat reservoir case. Since the temperature of both the high temperature and low temperature heat input is changing, the Carnot efficiency is also changing. This problem should be solved using a numerical technique that you write using either excel or Matlab. In…arrow_forward4. Steam enters the condenser of a steam power plant at 20000 kPa and a quality of 95 percent with a mass flow rate of 20 Mg/h. It is to be cooled by water from a nearby river in circulating the water through the tubes within the condenser. To prevent thermal pollution, the river water is not allowed to experience a temperature rise above 10°C. If the steam is to leave the condenser as saturated liquid at 20000 Pa, determine the mass flow rate of the cooling water required.arrow_forward
- Consider an aircraft powered by a turbojet engine that has a pressure ratio of 12. The aircraft is stationary on the ground, held in position by its brakes. The ambient air is at 27 deg.C and 95 kPa and enters the engine at a rate of 10 kg/s. The jet fuel has a heating value of 42,700 kJ/kg, and it is burned completely at a rate of 0.2 kg/s. Neglecting the effect of the diffuser and disregarding the slight increase in mass at the engine exit as well as the inefficiencies of engine components, determine the force that must be applied on the brakes to hold the plane stationary.arrow_forwardA heat engine produces 50 kW of power while consuming 50 kW of heat from a source at 1390 K, 70 kW of heat from a source at 1690 K , and rejecting the waste heat to the atmosphere at 300 K. Part A Determine the reversible power. Express your answer to three significant figures and include appropriate units. ? Value Units Submit Request Answer Part B Determine the rate of exergy destruction (I) in the engine's universe. Express your answer to three significant figures and include appropriate units. HẢ Value Unitsarrow_forwardAir (C, = 1005J/kg · °C) is to be preheated by hot exhaust gases in a cross-flow heat exchanger before it enters %3D the furnace. Air enters the heat exchanger at 95 kPa and 20°C at a rate of 0.8 m³ /s. The combustion gases (C, = 1100 J/kg · °C) enter at 180°C at a rate of 1.1 kg/s and leave at 95°C. The product of the overall heat %3D transfer coefficient and the heat transfer surface area is AU = 1200 W/°C. Assuming both fluids to be unmixed, determine the rate of heat transfer and the outlet temperature of the air Air 95 kPa 20°C 0.8 m/s Exhaust gases 1.1 kg/s 95°Carrow_forward
- A stream of methane(CH4, Cp=4R) flowing at 3.0 kmol/min is isobarically heated in a well‑insulated heat exchanger from 30.00 ∘C to 1.50×102 ∘C. The second side of the exchanger is fed with saturated water vapor, which is isobarically cooled to a saturated liquid when it leaves. As unit operator, you have the choice of feeding high‑pressure steam (HPS) at 4.00 MPa or medium pressure steam (MPS) at 1.00 MPa. Assume Tsurr=27 ∘C. Find the mass flow rate of water and lost work if high pressure steam (HPS) is used. Find the mass flow rate of water and lost work if medium pressure steam (MPS) is used. Which is the better choice of steam to use?arrow_forwardI got previous help from a Bartleby expert but unfortunately their answer was incorrect.arrow_forwardSteam at a pressure of 0.08 bar and a quality of 93.2% enters a shell-and-tube heat exchanger where it condenses on the outside of tubes through which cooling water flows, exiting as saturated liquid at 0.08 bar. The mass flow rate of the condensing steam is 5.8 x 105 kg/h. Cooling water enters the tubes at 15°C and exits at 35°C with negligible change in pressure. Neglecting stray heat transfer and ignoring kinetic and potential energy effects, determine the mass flow rate of the cooling water, in kg/h, for steady-state operation. mwater = i eTextbook and Media Save for Later kg/h Attempts: 0 of 5 used Submit Answerarrow_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
Thermodynamic Availability, What is?; Author: MechanicaLEi;https://www.youtube.com/watch?v=-04oxjgS99w;License: Standard Youtube License