Heat Transfer
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The document discusses different modes of heat transfer including conduction, convection, and radiation. It provides examples of heat transfer through a metal rod, fluid movement, and electromagnetic waves. Formulas are given for calculating heat transfer by conduction through plane walls, cylindrical pipes, and composite materials using thermal conductivity and temperature differences. Methods for determining overall heat transfer coefficients and heat exchangers are also summarized.
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This document summarizes the three main mechanisms of heat transfer: conduction, convection, and radiation. It explains key concepts for each type of transfer. Conduction involves the transfer of kinetic energy between molecules in direct contact. Convection involves the transfer of heat by the circulation of fluids (gases or liquids). Radiation involves the emission and absorption of electromagnetic waves. The document provides detailed explanations of these processes, factors that influence each type of transfer, and examples like the greenhouse effect and vacuum flasks.
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1) A heat and mass transfer exam with 8 questions across 2 parts (A and B). Questions cover topics like deriving the 3D heat conduction equation, calculating heat transfer coefficients, temperature distributions, and more.
2) Part A questions derive the 3D heat conduction equation, calculate heat loss from a insulated pipe, and determine the temperature distribution in a plate heater system.
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This ppt is use for find thermal conductivity of metal rod. including with examples of thermal conductivity.
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This document outlines an experiment to determine the thermal and electrical conductivity of metal rods. It describes measuring the heat capacity of a calorimeter and using it to calculate the thermal conductivity of a metal rod. Electrical conductivity is determined by measuring the current-voltage characteristic of a rod. The results are used to verify the Wiedemann-Franz law relating thermal and electrical conductivity. Modifications are proposed to better maintain steady temperatures in the calorimeter reservoirs during thermal conductivity measurements.
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Chemical engineering iiit rgukt Nuzvid a159050802436.pdf
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Conduction equation cartesian, Cylindrical, spherical (7).pptx
Conduction equation cartesian, Cylindrical, spherical (7).pptx
Heat transfer experiment for chemical engineering student
Heat transfer experiment for chemical engineering student
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Airconditioning system (ppt)
This document discusses air conditioning systems. It begins with an introduction defining air conditioning and its goals of altering air properties like temperature and humidity for comfort or industrial processes. It then discusses the principles, types, and components of air conditioning systems. The main types are window units, split systems, centralised systems, and packaged systems. It also introduces new technologies like district cooling systems and chilled beam systems. Finally, it discusses the refrigeration cycle and common coolants used.
Fundamentals of heat transfer lecture notes
This document discusses various modes of heat transfer including conduction, convection, and radiation. It provides equations to calculate heat transfer via these different modes. For conduction, Fourier's law and its relation to electrical resistance is explained. For convection, Newton's law of cooling and relationships between heat transfer coefficients, temperature differences and surface areas are given. Stefan-Boltzmann law is described for radiation heat transfer between black and gray bodies. Methods to relate convection and radiation heat transfer are also presented. Several examples are provided to demonstrate calculations of heat transfer via different modes.
Module 10 (air standard cycle)
The document describes three common internal combustion engine cycles: the Otto, Diesel, and Dual cycles. It provides diagrams and equations to illustrate the thermodynamic processes involved in each cycle, including compression, combustion, and expansion processes. Key parameters like compression ratio, cut-off ratio, pressure ratio, and thermal efficiency are defined. The cycles are compared in terms of their heat addition processes, net work output, and thermal efficiency calculations.
Module 9 (second law & carnot cycle)
1. The document discusses the Carnot cycle, which includes the Carnot engine and Carnot refrigerator. It uses the principles of the first and second laws of thermodynamics.
2. A Carnot engine operates between a high temperature TH and low temperature TL. Heat is added at TH and rejected at TL to produce net work. The efficiency depends only on TH and TL.
3. A Carnot refrigerator operates in reverse, absorbing heat at TL and rejecting it at TH, requiring net work. Its coefficient of performance depends only on TH and TL.
Module 8 (fuels and combustion)
This document discusses fuels and combustion. It defines a fuel as a substance that undergoes rapid chemical union with oxygen to produce combustion. Combustion is the rapid oxidation of an element that liberates heat. There are four main types of fuel: solid, liquid, gaseous, and nuclear. The main combustible elements are carbon, hydrogen, and sulfur. Hydrocarbons are the main components of fuels and can be paraffins, olefins, aromatics, or alcohols. Complete combustion occurs when all combustible elements are fully oxidized, while incomplete combustion occurs when some elements are not fully oxidized. Air is needed for combustion and is composed of oxygen and nitrogen. Theoretical air is the
Module 7 (processes of fluids)
An isobaric process is a constant pressure process where pressure (P) remains constant. Work (W) done is equal to pressure (P) times the change in volume (ΔV). For an ideal gas, the change in internal energy (ΔU) is equal to heat (Q) added.
An isometric process is a constant volume process where volume (V) remains constant. Work (W) done is zero since there is no change in volume. For any substance, the change in internal energy (ΔU) is equal to the heat (Q) added.
An isothermal process is a constant temperature process where temperature (T) remains constant. For an ideal gas, the ratio
Module 6 (ideal or perfect gas and gas mixture) 2021 2022
This document summarizes key concepts related to ideal gases. It defines the characteristic gas equation and gas constant. It describes Boyle's, Charles', Avogadro's, and combined gas laws. It also covers specific heats at constant pressure and volume, the ratio of specific heats, entropy change, non-ideal gas behavior, compressibility factor, and includes sample problems applying these concepts.
Module 5 (properties of pure substance)2021 2022
This document discusses properties of pure substances and steam. It defines key terms like saturation temperature, saturation pressure, subcooled liquid, compressed liquid, saturated mixture, and superheated vapor. It also describes temperature-specific volume, temperature-entropy, and enthalpy-entropy diagrams. Sample problems are provided to calculate properties like quality, enthalpy, specific volume, power output, and mass flow rate using steam tables and the concepts introduced.
Module 4 (first law of thermodynamics) 2021 2022
The document discusses the first law of thermodynamics, also known as the law of conservation of energy. It states that energy cannot be created or destroyed, only converted from one form to another. The first law is expressed mathematically as: Energy In - Energy Out = Change in Stored Energy. The document provides examples of applying the first law to closed and open systems, including deriving equations relating heat, work, internal energy, and other properties. It also includes examples solving thermodynamics problems for systems like turbines, compressors, and nozzles.
Module 2 (forms of energy) 2021 2022
1) The document defines various forms of energy including work, heat, internal energy, kinetic energy, potential energy, and enthalpy. It provides equations to calculate changes in these energy forms.
2) Two sample problems are included, one calculating potential energy change and velocity when a hammer is dropped, the other calculating drop height using given kinetic and potential energy changes.
Module 1 (terms and definition & properties of fluids)2021 2022
This document provides background information on important historical figures in the development of thermodynamics and related fields of physics and engineering. It discusses the contributions of scientists such as Archimedes, Daniel Bernoulli, Joseph Louis Gay-Lussac, Amedeo Avogadro, John Dalton, Lord Kelvin, Gabriel Fahrenheit, Galileo, Isaac Newton, Blaise Pascal, Robert Boyle, Albert Einstein, and others to establishing foundational principles of thermodynamics, mechanics, gas laws, and more. It also outlines key learning outcomes for a course module on thermodynamics.
Me 312 module 1
Combustion involves the reaction of fossil fuels like natural gas, coal, and gasoline with oxygen to produce heat. Fossil fuels are primarily composed of carbon and hydrogen. The main products of combustion are carbon dioxide and water. There are solid, liquid, and gaseous fuels that can undergo combustion. Complete combustion fully oxidizes the combustible elements, while incomplete combustion leaves some elements unoxidized, producing soot or smoke. Air contains oxygen and nitrogen that support combustion reactions.
Fuels and Combustion
This document provides an overview of heat transfer topics covered in a module, including objectives, topics, and introductions. The key topics are the three modes of heat transfer - conduction, convection, and radiation. Equations for calculating heat transfer via these three modes are presented, including Fourier's law of conduction, Newton's law of cooling for convection, and the Stefan-Boltzmann law for radiation. Examples of combined radiation and convection heat transfer are also discussed.
Fluid mechanics ( 2019 2020)
This course provides an introduction to fluid mechanics concepts including pressure, hydrostatics, buoyancy, momentum and mass conservation, and their applications to fluid systems analysis and design. Students will learn to calculate forces in static and flowing fluids, flow velocities, pressure losses, and dimensionless numbers. They will also learn the properties of laminar and turbulent boundary layers and how to apply Bernoulli's principle to fluid problems. The overall aim is for students to develop skills in solving practical fluid mechanics problems relevant to engineering.
AIR STANDARD CYCLE
This document provides information about various air standard cycles used in internal combustion engines, including the Otto, Diesel, and Dual cycles. It defines the key processes and equations for each cycle. The Otto cycle involves four processes: isentropic compression, constant volume heat addition, isentropic expansion, and constant volume heat rejection. The Diesel cycle involves: isentropic compression, constant pressure heat addition, isentropic expansion, and constant volume heat rejection. The Dual cycle combines aspects of the Otto and Diesel cycles, involving five processes. Thermodynamic relationships between pressure, volume, temperature and other variables are defined through equations for each cycle.
Me 12 quiz no. 3
1. The document contains 4 problems involving compressed gases and thermodynamic processes. Problem 1 involves determining the pressure reading of a manometer connected to a tank containing compressed air and oil. Problem 2 involves determining the air pressure in a storage tank using the pressure reading in a pipe containing a different fluid. Problem 3 involves calculating the work done and heat transferred during an isothermal expansion process of air in a piston cylinder device. Problem 4 involves sketching and analyzing an isothermal compression followed by a constant pressure compression process of air on PV and TS diagrams.
Chapter 7 Processes of Fluids
1. The document describes various thermodynamic processes including isobaric, isometric, isothermal, isentropic, and polytropic processes.
2. For isobaric processes in closed systems, work done is equal to pressure times change in volume. For open systems at constant pressure, work done is zero and heat absorbed is equal to enthalpy change.
3. For isentropic processes in closed systems, work done is equal to the negative change in internal energy, and for open systems work done is equal to the negative enthalpy change.
Chapter 6 Gas Mixture
This document outlines various laws and equations relating to gas mixtures, including:
1) Dalton's Law which states that the total pressure of a gas mixture is equal to the sum of the partial pressures of the individual components.
2) Amagat's Law which describes how the total volume of a gas mixture is equal to the sum of the volumes the components would occupy individually at the same temperature and pressure.
3) Equations for determining the molecular weight, gas constant, and specific heat of a gas mixture based on the properties of its individual components.
Chapter 5 (ideal gas & gas mixture)
1. The document defines key concepts related to ideal gases including the ideal gas law, gas constant, Boyle's law, Charles' law, Avogadro's law, specific heat, ratio of specific heats, entropy change, gas mixtures, and processes involving gases.
2. It provides equations of state for ideal gases, gas mixtures, and non-ideal gases. Equations are given for properties of gas mixtures including volume, pressure, molecular weight, and specific heat.
3. Key thermodynamic processes involving gases are summarized including isobaric and isometric processes for both closed and open systems, with equations provided for heat, work, internal energy, and entropy changes.
Chapter 4 (propertiesof pure substance)
This document discusses the properties of pure substances during phase changes. It defines key terms like saturation temperature, saturation pressure, sub-cooled liquid, saturated liquid, saturated vapor, and superheated vapor. The document explains that 100°C is the saturation temperature corresponding to a pressure of 101.325 kPa. It also provides diagrams to illustrate the different regions on a T-S and h-S chart during phase changes and defines concepts like quality.
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Heat Transfer
- 1. Heat Transfer It is that area of mechanical engineering that deals with the different principles and mechanisms involved in transferring heat from one point to another. Heat Transfer
- 3. Conduction fire Metal rod t 1 Hotter body t 2 Colder body
- 4. Convection 2 t 2 t 1 1 Fluid surface
- 5. Radiation Hot body Cold body
- 6. Conduction L 1 2 k A Q t 1 t 2 Where: L – thickness, meters A – surface area, m 2 k – thermal conductivity, Q – conductive heat flow, Watts
- 7. Thermal Circuit Diagram 1 2 R Q
- 8. Conduction through a Composite Plane Wall L 1 L 2 L 3 k 1 k 2 k 3 1 A 2 3 4 Q
- 9. Thermal Circuit Diagram 1 2 R 1 Q 4 3 R 2 R 3
- 10. A furnace is constructed with 20 cm of firebrick, k = 1.36 W/m- K, 10 cm of insulating brick, k = 0.26 W/m- K, and 20 cm of building brick, k = 0.69 W/m- K. The inside surface temperature is 650 C. The heat loss from the furnace wall is 56 W/m 2 . Determine a. the interface temperature and the outside wall temperature, C b. the total resistance R t, for 1 m 2 Given: L 1 =0.20 m ; L 2 = 0.10 m ; L 3 = 0.20 m k 1 = 1.46 ; k 2 = 0.26 ; k 3 = 0.69 t 1 = 650 C Q/A = 56 W/m 2 L 1 L 2 L 3 1 2 3 4 Q A 1 2 R 1 Q 4 3 R 2 R 3
- 11. At 1 to 2 At 1 to 3 At 1 to 4
- 12. Convection Where: Q – convective heat flow, Watts A – surface area in contact with the fluid, m 2 h – convective coefficient, W/m 2 - C or W/m 2 -K t 1 , t 2 – temperature, C Fluid A 1 2 Q t 2 t 1 h
- 13. Conduction from Fluid to Fluid separated by a composite plane wall L 1 L 2 L 3 k 1 k 2 k 3 1 A 2 3 4 Q i h i t i o h o , t o
- 14. Thermal Circuit Diagram 1 2 R 1 Q 4 3 R 2 R 3 i o R i R o
- 15. Overall Coefficient of Heat Transfer Where: U – overall coefficient of heat transfer, W/m 2 - C or W/m 2 -K
- 16. CONDUCTION THROUGH CYLINDRICAL COORDINATES Where: r 1 – inside radius, m r 2 – outside radius, m L – length of pipe, m k – thermal conductivity of material, W/m- C r 1 r 2 1 2 t 1 t 2 Q k
- 17. For composite cylindrical pipes (Insulated pipe) r 1 r 2 1 2 t 1 t 2 Q k 1 3 r 3 t 3 k 2
- 18. Heat Flow from fluid to fluid separated by a composite cylindrical wall r 1 r 2 1 2 t 1 t 2 Q k 1 3 r 3 t 3 k 2 i h i t i o h o t o
- 19. Overall Coefficient of Heat Transfer
- 20. Heat Exchangers Types of Heat Exchangers 1. Direct Contact Type: The same fluid at different states are mixed. 2. Shell and Tube Type: One fluid flows inside the tubes and the other fluid on the outside. Direct Contact m 1 , h 1 m 2 , h 2 m 3 , h 3
- 22. Shell and Tube Type m c m c m h m h 1 2 A B t wA t wB h 1 h 2
- 23. By energy balance Heat rejected by the hot fluid = Heat absorbed by the cold fluid Where: m c – mass flow rate of cold fluid, kg/sec m h – mass flow rate of hot fluid, kg/sec h – enthalpy, kj/kg t – temperature, C C pc – specific heat of the cold fluid, KJ/kg- C Q – heat transfer, KW h, c – refers to hot and cold, respectively 1, 2 – refers to entering and leaving conditions of hot fluid A, B – refers to entering and leaving conditions of cold fluid
- 24. Heat Transfer in terms of OVERALL COEFFICIENT Of HEAT TRANSFER U
- 25. Log Mean Temperature Difference (LMTD) Where: 1 – small terminal temperature difference, C 2 – large terminal temperature diffrence, C
Editor's Notes
- Modes of Heat Transfer