Anh văn chuyên ngành Nhiệt chapter 5

Anh văn Chuyên ngành Nhiệt English for thermal engineering LOGO Chapter Boiler and the thermal power plants Contents 5.1 Rankine Cycle 5.2 The Boiler 5.3 The thermal power plants Tài liệu tham khảo Fundamentals of thermal-fluid science, Y A Çengel Fundamentals of thermodynamics (sixth edition), Sonntag, Borgnakke and van Wylen Steam plant operation (Eighth edition), Everett B Woodruff, Herbert B Lammers, Thomas B Lammers 5.1 Rankine cycle: The ideal cycle The ideal Rankine cycle does not involve any internal irreversibilities and consists of the following four processes: 1-2 Isentropic compression in a pump 2-3 Constant pressure heat addition in a boiler 3-4 Isentropic expansion in a turbine 4-1 Constant pressure heat rejection in a condenser 5.1 Rankine cycle: The ideal cycle Energy Analysis of the Ideal Rankine Cycle The pump, boiler, turbine, and condenser are steady-flow devices, and thus all four processes that make up the Rankine cycle can be analyzed as steady-flow processes The steady-flow energy equation per unit mass of steam reduces to:  Pump (q = 0):  Boiler (w = 0): The thermal efficiency of the Rankine cycle:  Turbine (q = 0):  Condenser (w = 0): 5.1 Rankine cycle: The ideal cycle The Simple Ideal Rankine Cycle Consider a steam power plant operating on the simple ideal Rankine cycle The steam enters the turbine at MPa and 350˚C and is condensed in the condenser at a pressure of 75 kPa Determine the thermal efficiency of this cycle 5.1 Rankine cycle: The ideal cycle 5.1 Rankine cycle: The ideal cycle 5.1 Rankine cycle: The ideal cycle Actual vapor power cycles Fluid friction causes pressure drops in the boiler, the condenser, and the piping between various components; The heat loss from the steam to the surroundings as the steam flows through various components (a) Deviation of actual vapor power cycle from the ideal Rankine cycle; (b) The effect of pump and turbine irreversibilities on the ideal Rankine cycle 5.1 Rankine cycle: The ideal cycle Actual vapor power cycles The irreversibilities occurring within the pump and the turbine A greater work input in pump, and a smaller work output in turbine Isentropic efficiencies and where states 2a and 4a are the actual exit states of the pump and the turbine, respectively, and 2s and 4s are the corresponding states for the isentropic case 10 Circulation System Circulation System •Economizer •Superheater •Reheater •Header •Drum •Waterwall •BWCP Header ReHeater Gas Super Heater Coils : - Econimizer - Superheater - Reheater 30 Circulation System Circulation System •Economizer •Superheater •Reheater •Header •Drum •Waterwall •BWCP Super Heater Reheater Economizer [(Drum) ] [ Water wall ] [ BWCP, Boiler Water Circulation Pump ] 31 Boiler Components & Equipment Circulation System Firing Sys • Pulverizer • Burner Draft Sys Environ Sys C&I Heat Exchanger 32 Firing System Firing Sys - Pulverizer or Mill Raw Coal Pulverized Coal • Pulverizer • Burner Roller Primary Air 33 Firing System - Burner Firing Sys • Pulverizer • Burner [ Burner & Windbox ] [ Oil gun and CFS nozzles ] 34 Draft System Circulation System Firing Sys Flue Gas Coal Bunker Draft Sys Primary Air 2nd Air (Fuel Air) Environ Sys C&I 1st Air Air Duct Heat Exchanger Gas Duct Stack (Hot) Air Preheater Air Duct Raw Coal Gas Duct 1st Air (Cold) ID Fans 35 Draft System Draft Sys 1) Fans • Forced Draft Fan, FDF • Fans • Ductworks • Air Heater - supplys air necessary for fuel combustion • Primary Air Fan, PAF - supplys air needed to dry and transport coal from mills to the furnace • Induced Draft Fan, IDF - exhausts flue gas from the furnace with suction force [Induced Fan] 36 Draft System 2) Ductworks Draft Sys • Fans • Ductworks • Air Heater 37 Draft System 3) Air Heater • Air heater transfers sensible heat in the flue gas to the combustion air supplied by FD or PA fan Draft Sys • Fans • Ductworks • Air Heater 38 Ⅰ Overview – Boiler Components & Equipment Circulation System Firing Sys Draft Sys Environ Sys • SCR • EP • FGD C&I Heat Exchanger 39 Environmental Protection System Circulation System 1) Selective Catalystic NOx Reduction System (SCR) Firing Sys Draft Sys Environ Sys • SCR • EP • FGD C&I Heat Exchanger 40 Environmental Protection System 2) Electrostatic Precipitator (EP) Circulation System Firing Sys Draft Sys Environ Sys • SCR • EP • FGD C&I Heat Exchanger 41 Environmental Protection System Circulation System 3) Flue Gas Desulphurization System (FGD) Gas Outlet Firing Sys Draft Sys Environ Sys • SCR • EP • FGD C&I Heat Exchanger Gas Inlet Limestone Slurry 42 Heat Exchangers Circulation System Firing Sys Draft Sys Condenser Environ Sys C&I Heat Exchanger • Condenser • Deaerator • Feedwater Heater Feedwater Heater Deaerator Condenser Tube Cleaning System & Debris Filter 43 http://blogcongdong.com LOGO 44 ... fire-tube boiler, submerged tube type 18 5. 2 The Boiler Fire-Tube Boilers  Capacity: to 75 bhp (4.47 kW – 55 .8 75 kW)  Tube diameter size: from 2’ to 3’ (50 .8 - 76.2 mm)  Pressures to 100 psi... Aqua-Chem, Inc.) 20 5. 2 The Boiler Horizontal fire-tube boilers Available Capacity: 15 to 800 bhp Steam flow: 1000 to 28,000 lb/h (maximum 50 ,000 lb/h) Pressures of 15 to 350 psi Fuels: Solid.. .Chapter Boiler and the thermal power plants Contents 5. 1 Rankine Cycle 5. 2 The Boiler 5. 3 The thermal power plants Tài liệu tham khảo Fundamentals