Anh Văn Công Nghệ Nhiệt

Anh văn Chuyên ngành Nhiệt English for thermal engineering LOGO Contents Introduction to thermodynamics Psychrometrics The laws of thermodynamics Reversed cycles and refrigeration air conditioning Boiler and thermal power plant Tài liệu tham khảo Fundamentals of thermal-fluid science, Y A Çengel Fundamentals of thermodynamics (sixth edition), Sonntag, Borgnakke and van Wylen Fundamentals of engineering thermodynamics (Fifth edition), Michael J Moran, Howard N Shapiro English for thermal engineering, Đặng Thành Trung, ĐHQG-HCM Những trang Web tra từ chuẩn Cambridge: dictionary.cambridge.org/Default.asp?dict=CALD Oxford: www.oup.com/elt/catalogue/teachersites/oald7/?cc=global Longman: www.ldoceonline.com dictionary.reference.com www.merriam-webster.com www.thefreedictionary.com www.yourdictionary.com Chapter 1: Introduction to thermodynamics 1.System Definition: A system is defined as a quantity of matter or a region in space chosen for study The mass or region outside the system the surroundings The real or imaginary surface that separates the system from its surroundings is called the boundary Classification * Closed system (control mass) * Open system (control volume) Chapter 1: Introduction to thermodynamics 1.System Classification * Closed system (control mass): - A fixed amount of mass, and no mass can cross its boundary - Energy, in the form of heat or work, can cross the boundary; And the volume of a closed system does not have to be fixed - An isolated system which is not allowed mass and energy to cross the boundary Chapter 1: Introduction to thermodynamics 1.System Classification * Open system (control volume): Both mass and energy can cross the boundary of a control volume It usually encloses a device that involves mass flow such as a compressor, turbine, or nozzle Chapter 1: Introduction to thermodynamics Absolute pressure Atmospheric pressure The force of a fluid acting on unit area p, [Pascal, Pa] The pressure due to the force by the atmosphere’s mass pa = 760 mmHg (at sea level, 150C) 2.Pressure Gage pressure The difference between the absolute pressure and the atmospheric pressure, and the difference is positive pg= p – pa > Vacuum pressure The difference between the absolute pressure and the atmospheric pressure, and the difference is negative pv= p – pa < Chapter 1: Introduction to thermodynamics Pressure’s units: Chapter 1: Introduction to thermodynamics 3.Temperature Definition: The measurement of the degree of hotness or coolness is temperature Temperature scales: Celsius (0C), Fahrenheit (0F), Kelvin (K) Conversion of temperature scales: 0C = 5/9(0F-32); K = 0C + 273.15; 0F = 9/50C + 32 Chapter 1: Introduction to thermodynamics 3.Temperature The Zeroth Law of thermodynamics: Two bodies each in thermal equilibrium with a third body will be in thermal equilibrium with each other : Notice: The Zeroth Law of thermodynamics is a basis for the validity of temperature measurement Chapter 1: Introduction to thermodynamics 3.Temperature Thermometer: A device is used to measure temperature, by using materials that change in some way when they are heated or cooled Thermometers (a) Liquid-in-glass; (b) Infrared - sensing ear thermometer Chapter 1: Introduction to thermodynamics 4.Heat transfer Definition Heat is defined as the form of energy that is transferred between two systems (or a system and its surroundings) by virtue of a temperature difference (t  0) Heat exists only as it crosses the boundary of a system and the direction of heat transfer is from higher temperature to lower temperature Units: Calorie (Cal), Joule (J), Btu Unit conversion: Btu = 1055.056 J; cal = 4.184 J; 1N.m = J Chapter 1: Introduction to thermodynamics 4.Heat transfer Sensible Heat is an interaction energy related to changes in temperature of a gas or object with no change in phase Latent Heat is defined as the energy absorbed by or released from a substance during a phase change from a gas to a liquid or a solid Heat transferred to a system Heat transferred from a system Chapter 1: Introduction to thermodynamics 4.Heat transfer Specific heat: the measure of the amount of heat required to raise the temperature of a unit mass of a substance one degree Cp is specific heat of the object at constant pressure Cv is specific heat of the object at constant volume Chapter 1: Introduction to thermodynamics 4.Heat transfer Ideal-gas specific heats of various common gases: Chapter 1: Introduction to thermodynamics 4.Heat transfer Modes of heat transfer Conduction: Heat transferred between two bodies in direct contact Convection: Heat transfer between a solid surface and an adjacent gas or liquid Thermal Radiation: The energy emitted by matter in the form of electromagnetic waves as a result of the changes in the electronic configurations of the atoms or molecules Chapter 1: Introduction to thermodynamics 4.Heat transfer Modes of heat transfer Chapter 1: Introduction to thermodynamics Work, W [J]: Definition: Work, like heat, is an energy interaction between a system and its surroundings In other word, work is the energy transfer associated with a force acting through a distance W > 0: Work transferred out of a system W < 0: Work transferred in a system Chapter 1: Introduction to thermodynamics Work, W [J]: Formula: For a change in volume from V1 to V2, the work is obtained: Vocabulary Thermodynamics (θɜ:məudai'nỉmiks): Nhiệt đợng học System (ˈsɪs.təm): Hệ nhiệt động Boundary (ˈbaʊn.dər.i): Biên hệ NĐ Text Surrounding (səˈraʊnd): Môi trường xung quanh Pressure ('preʃə): Áp śt Absolute (ˈỉb.sə.luːt):Tụt đới Absolute pressure (n): Áp śt tụt đới Text Vacuum ('vỉkjuːm) : Chân không Vacuum pressure (n): Áp suất chân không Text Atmosphere (ˈỉt.mə.sfɪə): Khí qủn Temperature (ˈtem.prə.tʃər): Nhiệt đợ Fluid (ˈfluː.ɪd): Chất lỏng Conduction (kənˈdʌk.ʃən): Dẫn nhiệt Convection (kənˈvek.ʃən): Đối lưu nhiệt Radiation (ˌreɪ.diˈeɪ.ʃən): Bức xạ nhiệtText Sensible (ˈsen.sə.bəl) heat: Nhiệt hiện Latent (ˈleɪ.tənt) heat: Nhiệt ẩn Passive Text Text Text Text http://blogcongdong.com LOGO ... nhiệt động Boundary (ˈbaʊn.dər.i): Biên hệ NĐ Text Surrounding (səˈraʊnd): Môi trường xung quanh Pressure ('preʃə): Áp śt Absolute (ˈỉb.sə.luːt):Tụt đới Absolute pressure (n): Áp śt tụt