Diese Präsentation wurde erfolgreich gemeldet.
Wir verwenden Ihre LinkedIn Profilangaben und Informationen zu Ihren Aktivitäten, um Anzeigen zu personalisieren und Ihnen relevantere Inhalte anzuzeigen. Sie können Ihre Anzeigeneinstellungen jederzeit ändern.

Steam generator part 2

12.328 Aufrufe

Veröffentlicht am

Hello,
I am trying to explain about Steam Generator (Boiler) in this session, due to length of said presentation, I am deciding to divide it in three parts.
Part 1 cover the “Introduction & Types of Steam Generator”
Part 2 cover about the “Parts of Steam Generator and Its Accessories & Auxiliaries” and
Part 3 cover the “Efficiency & Performance”

Veröffentlicht in: Ingenieurwesen

Steam generator part 2

  1. 1. BOILER Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Saba Power Plant
  2. 2. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Saba Power Plant Steam Generator (Boiler) Hello, I am trying to explain about Steam Generator (Boiler) in this session, due to length of said presentation, I am deciding to divide it in three parts. Part 1 cover the “Introduction & Types of Steam Generator” Part 2 cover about the “Parts of Steam Generator and Its Accessories & Auxiliaries” and Part 3 cover the “Efficiency & Performance”
  3. 3. BOILER Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Saba Power Plant Part 2
  4. 4. PARTS OF BOILER Boiler parts are divided into three main classes: • Boiler Mountings & Accessories • Boiler Auxiliaries. • Boiler Safety (Protections) Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  5. 5. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Saba Power Plant
  6. 6. FIRE TUBE BOILER Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  7. 7. Mountings: There are the fittings which are mounted on the boiler for its proper functioning. A boiler cannot function safely without mountings. Through there are many types of boiler mountings yet the following are important from the subject point view. a. Water level indicator b. Pressure gauge c. Safety valves d. Stop valve e. Blow off cock f. Feed check valve g. Fusible plug h. Blow down valve i. Man hole and Mud Box j. Blow-off cock Boiler Mountings and Accessories Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  8. 8. Simple Vertical Boiler: The image shows the simplest form of an internally fired vertical fire-tube boiler. It does not require heavy foundation and requires very small floor area. Parts • Cylinder Shell • Cross Tubes • Furnace or Fire Box • Grate • Fire Door • Chimney or Stack • Manhole • Hand Hole • Ash Pit FIRE TUBE BOILER Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  9. 9. FIRE TUBE BOILER Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Cochran Boiler
  10. 10. Locomotive Boiler FIRE TUBE BOILER Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  11. 11. Locomotive Boiler FIRE TUBE BOILER Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  12. 12. Lancashire Boiler Components Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  13. 13. Cornish Boiler FIRE TUBE BOILER Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  14. 14. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Saba Power Plant
  15. 15. These are the devices which form an integral part of a boiler but are not mounted on it. It may be noted that the accessories help in controlling and running the boiler efficiency Though there are many types of accessories yet the following are important from the subject point of view. • Steam drum. • Mud drum • Super heater & Its attemperator • Re-Heater & Its attemperator • Economizer • Down comers. • Headers • Generation tubes (Up risers) Water walls. • Air preheater System (Regenerative air heater & SCAPH) • Soot Blowers • Furnace. • Burners & Its Accessories (Air register, Dampers, Flame Detector) • Boiler Drains & Vents System • Stack/Chimney. Boiler Mountings and Accessories Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Accessories:
  16. 16. Boiler auxiliaries have the following parts: • Induced draft fan (IDF). • Forced draft fan (FDF). • Recirculation fan (RCF). • Fan Dampers • Feed water pump • Atomizing Air or Steam System • Chemical Feed System • Seal Air Blower • Flame Scanner Cooling Blower • Fuel System • ESP • Ash Handling System • Blowdown Tank • Service & Instrument Air System BOILER AUXILIARIES Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  17. 17. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Saba Power Plant
  18. 18. These are the devices which form an integral part of a boiler but are not mounted on it. It may be noted that the accessories help in controlling and running the boiler efficiency Though there are many types of accessories yet the following are important from the subject point of view. • Steam drum. • Mud drum • Super heater & Its attemperator • Re-Heater & Its attemperator • Economizer • Down comers. • Headers • Generation tubes (Up risers) Water walls. • Air preheater System (Regenerative air heater & SCAPH) • Soot Blowers • Furnace. • Burners & Its Accessories (Air register, Dampers, Flame Detector) • Boiler Drains & Vents System • Stack/Chimney. Boiler Mountings and Accessories Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Accessories:
  19. 19. The accessories include – 1. Economizer 2. Boiler Drum 3. Down comers 4. Water walls 5. Water wall plates (used for low- pressure boilers) 6. Primary super heater 7. Platen super heater 8. Final Super heater 9. Reheater 10. Burner 11. Igniters. A brief note on some of the major components shows in figure Boiler Mountings and Accessories Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Saba Power Plant
  20. 20. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift SupervisorBoiler Accessories
  21. 21. WATER TUBE BOILER Babcock and Wilcox boiler. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  22. 22. WATER TUBE BOILER Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Saba Power Plant
  23. 23. WATER TUBE BOILER Double Furnace Boiler Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Saba Power Plant
  24. 24. Waste Heat Boiler (HRSG) Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  25. 25. Waste Heat Boiler (HRSG) Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  26. 26. Nuclear Steam Generating Systems Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  27. 27. Steam Drum Internals Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor a. Steam purification equipment, including dry pan separators, plate-type baffles and other devices as necessary, to meet steam quality requirements and provide proper water levels in the boiler steam drum. b. Boiler feedwater admission system to properly distribute feedwater. c. Chemical feed piping to permit infusion of mixture of water treatment compounds along entire length of drum by continuous feed system.
  28. 28. Steam Drum Internals d. Continuous blowdown and water sampling system as combined unit designed to collect water along entire length of drum. e. Bottom drum blowoff system to properly collect sediment from bottom drum and to permit complete collection of sediment and drainage. f. Steam heating pipes in bottom drum to keep boiler warm on standby. Cap for future connections of steam supply and condensate return. g. Drum internal fittings shall be provided, securely mounted and easily removable for boiler internal access for inspections and cleaning. Steam Drum Internals Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  29. 29. Steam Drum Internals Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  30. 30. Steam Drum Internals Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  31. 31. Mud Drum A drum beneath a boiler, into which sediment and mud in the water can settle for removal. It is related with "bottom" blow down which reduces the quantity of un-dissolved solids (sludge) which collect in the lower parts of the boiler (mud drum). Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  32. 32. Super heater Coils: A superheater is a device used to convert saturated steam or wet steam into dry steam used in Steam turbines or in processes, such as steam reforming. There are three types of superheaters: radiant, convection, and separately fired. 1. A radiant superheater is placed directly in the combustion chamber. 2. A convection superheater is located in the path of the hot gases. 3. A separately fired superheater, as its name implies, is totally separated from the boiler. A Attemperator is provided to control the super heated steam temperature. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  33. 33. Steam from the exhaust of the first stage turbine goes back to the boiler for reheating and is returned to the second stage. Reheater coils in the flue gas path does the reheating of the returned steam. The reheat steam is at a much lower pressure than the super heated steam but the final reheater temperature is the same as the superheated steam temperature. Reheating to high temperatures improves the output and efficiency of the Power Plant. Final Reheater temperatures are normally in the range of 530 to 600 °C. Reheat steam pressures are normally around 45 bar. A attemperator is provided to control the Re-Heater steam temperature. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Re-Heater
  34. 34. Economizer coils are used in downstream of Boiler bank to preheat the feed water absorbing heat from hot exhaust gases. Economizers are always water tube type. Economizers have different types of Tubes depending upon the application. Bare tubes in Economizers are widely used in Industrial boilers and for applications like Heat recovery boilers in Sulfuric acid plants, gilled tubes are employed. Finned tubes are popular in HRSG applications. Feed water can be heated up to a level about 20 - 30 oC below saturation temperature of the boiler. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Economizer Coils
  35. 35. Downcomers are pipes leading from the top to the bottom of the boiler. Downcomers carry the water from steam drum to the bottom part of the boilers. Downcomers Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  36. 36. Headers form an important part of all types of boilers. Steam from the generating tubes is collected in headers which are therefore always under pressure. This pressure may vary from 300 psi to 2000 psi. Since headers are always under pressure, the utmost care is taken by us while fabricating them. Depending on the generating capacity of the boiler the header sizes fabricated by us vary from 100 mm to 600 mm NB. The stubs of various sizes are very carefully welded to the main body of the header to provide the desired openings from the header. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Headers:
  37. 37. These are tubes in the Boiler where water is evaporated to steam and are also called Steam Generating Tubes. These Tubes also form the Walls of the Boiler and are hence called Water Walls or Water Wall Panels. These Tubes have very complicated shapes to allow Inspection openings and burner throats and fabrication require intricate binding on CNC programmable bending Machines and checking on 3D layouts. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Water Wall Tubes:
  38. 38. SCAPH (Steam Coil Air Pres Heater Steam Coil Air Pre Heater (SCAPH) is an extended surface type heat exchanger. This equipment is used to heat atmospheric air to the required process temperature by means of saturated steam. Steam flows inside the tube while air passes over the finned tubes . Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Saba Power Plant
  39. 39. SCAPH (Steam Coil Air Pres Heater Steam coil air preheaters ( SCAPHS ) are used to heat air entering the air heater recuperative or regenerative type, in order to raise the average cold end temperature to prevent acid dew point corrosion. This type of equipment is normally incorporated into the design of a boiler unit for low load operation and startup operation particularly in those areas with low ambient air temperatures. They are desirable in that the main air heaters, recuperative or regenerative, have corrosion sections that are more readily maintained This type of air heater uses extended surface, normally referred to as fins, to reduce the overall size of this air preheater. It is generally located in the duct between the FD fan and the main air heater. in those areas that have extremely low ambient air temperatures, it is common to have this ahead of the FD fan that could preheat cold winter air up to about 40 degrees F. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Saba Power Plant
  40. 40. Air Pre-Heater In this type of preheater, heat is transferred from the flue gases to a matrix, which is then cooled by the combustion air, thereby preheating the air. For fired heater and boiler applications, regenerators are usually of the rotary type. The rotary regenerator preheater know as the Lungstrom wheel consists of elements, usually metallic, which are contained in a cylinder which flows through one side as the cylinder and is subsequently cooled by the combustion air on the other side as the wheel rotates. There are seals between the cylinder and casing to limit the amount of leakage from the airside to the flue gas side. This leakage lowers the gas exit temperature by 10 to 15 oC which in turn limits the level of efficiency normally occur at the end of the elements which will require periodic replacement Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  41. 41. Soot Blowers A soot blower is a system for removing the Soot that is deposited on the furnace tubes of a boiler during combustion. In oil fired boilers, over a period of time the heat transfer tubes get covered by a layer of soot or fine carbon deposit. This reduces the heat transfer from the hot gases to the water and reduces the efficiency of the boiler. In coal fired boilers, the furnace area gets covered by slag which is molten ash. The ash also sticks to the heat transfer surface in the other heat transfer areas. These ash accumulations reduce heat transfer and increase the tube metal temperatures leading to failure of the tubes. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  42. 42. Types of soot blowers: 1. One with a very long lance called the “long retractable soot blowers.” This is normally used to clean the ash deposit from between the coils of superheaters and economizers. 2. The other type is the shorter lance type called the “wall blowers.” These are used to clean the furnace walls. The lance extends a short distance around 200 mm from the furnace wall. The nozzle direction is such that the steam impinges on the walls cleaning the surface. During operation, the lance rotates cleaning the radial area covered by the steam from the nozzle. 3. Air Heater Blower. Soot blowing medium: Steam Air Steam is normally used as a medium for blowing away the soot since capital cost of steam pressure reducing equipment and drain is less than the cost of compressor, motors and control of air systems. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Soot Blowers
  43. 43. A furnace is a device used for heating. The name derives from Latin fornax, oven. Furnace An industrial furnace or direct fired heater, is an equipment used to provide heat for a process or can serve as reactor which provides heats of reaction. Furnace designs vary as to its function, heating duty, type of fuel and method of introducing combustion air. However, most process furnaces have some common features. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Saba Power Plant
  44. 44. Fuel flows into the burner and is burnt with air provided from an air blower. There can be one or more than one burner in a particular furnace which can be arranged in cells which heat a particular set of tubes. Burners can also be floor mounted, wall mounted or roof mounted depending on design. The flames heat up the tubes, which in turn heat the fluid inside in the first part of the furnace known as the radiant section or firebox. In this chamber where combustion takes place, the heat is transferred mainly by radiation to tubes around the fire in the chamber. The heating fluid passes through the tubes and is thus heated to the desired temperature. The gases from the combustion are known as flue gas. After the flue gas leaves the firebox, most furnace designs include a convection section where more heat is recovered before venting to the atmosphere through the flue gas stack. Furnace Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Saba Power Plant
  45. 45. Burners: The burner is the device that permits controlled burning of fuel inside the furnace. The burner mixes the fuel with the required amount of air and directs the flame into the combustion area. The burner comprises of gas burner and oil burner with atomizing steam connection. Burner consists of: · Air Register: used to give an enough quantity of air to the burner for good combustion. · Ignition Gun: used to give ignition spark to the burner for firing. · Flame Detector: used to monitor the flame. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Saba Power Plant
  46. 46. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  47. 47. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Oil Burner
  48. 48. Pulverized Coal Burner Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Saba Power Plant
  49. 49. Oil Burners Pressure jet burners A pressure jet burner is simply an orifice at the end of a pressurised tube. Typically the fuel oil pressure is in the range 7 to 15 bar. In the operating range, the substantial pressure drop created over the orifice when the fuel is discharged into the furnace results in atomization of the fuel. Putting a thumb over the end of a garden hosepipe creates the same effect. Varying the pressure of the fuel oil immediately before the orifice (nozzle) controls the flowrate of fuel from the burner. Advantages of pressure jet burners: Relatively low cost. Simple to maintain. Disadvantages of pressure jet burners: If the plant operating characteristics vary considerably over the course of a day, then the boiler will have to be taken off-line to change the nozzle. Easily blocked by debris. This means that well maintained, fine mesh strainers are essential. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  50. 50. Oil burners Rotary cup burner: Fuel oil is supplied down a central tube, and discharges onto the inside surface of a rapidly rotating cone. As the fuel oil moves along the cup (due to the absence of a centripetal force) the oil film becomes progressively thinner as the circumference of the cap increases. Eventually, the fuel oil is discharged from the lip of the cone as a fine spray. Because the atomization is produced by the rotating cup, rather than by some function of the fuel oil (e.g. pressure), the turndown ratio is much greater than the pressure jet burner. Advantages of rotary cup burners: Robust. Good turndown ratio. Fuel viscosity is less critical. Disadvantages of rotary cup burners: More expensive to buy and maintain. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  51. 51. Gas burners Being a gas, atomization is not an issue, and proper mixing of gas with the appropriate amount of air is all that is required for combustion. Two types of gas burner are in use 'Low pressure' and 'High pressure'. Low pressure burner These operate at low pressure, usually between 2.5 and 10 mbar. The burner is a simple venturi device with gas introduced in the throat area, and combustion air being drawn in from around the outside. Output is limited to approximately 1 MW. High pressure burner These operate at higher pressures, usually between 12 and 175 mbar, and may include a number of nozzles to produce a particular flame shape. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  52. 52. Gas Burner Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Saba Power Plant
  53. 53. Dual fuel burners The attractive 'interruptible' gas tariff means that it is the choice of the vast majority of organizations in the world. However, many of these organizations need to continue operation if the gas supply is interrupted. These burners are designed with gas as the main fuel, but have an additional facility for burning fuel oil. The notice given by the Gas Company that supply is to be interrupted may be short, so the change over to fuel oil firing is made as rapidly as possible, the usual procedure being: Isolate the gas supply line. Open the oil supply line and switch on the fuel pump. Purge and re-fire the boiler. On the burner control panel, select 'oil firing' (This will change the air settings for the different fuel). This operation can be carried out in quite a short period. In some organizations the change over may be carried out as part of a periodic drill to ensure that operators are familiar with the procedure, and any necessary equipment is available. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  54. 54. The difference between atmospheric pressure and the pressure existing in the furnace or flue gas passage of a boiler is termed as draft. Draft can also be referred to the difference in pressure in the combustion chamber area which results in the motion of the flue gases and the air flow. Types of Draft Drafts are produced by produced the rising of the combustion gases in the stack, or by mechanical means, for example a blower and can be put into four categories: natural, induced, balanced, and forced. Boiler Draft Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  55. 55. Natural draft: when air or flue gases flow due the difference in the density and acted upon by the force of gravity in stacks is a natural draft system. Simply put, the difference between the density between the hot flue gases and the cold gases in the surroundings results in a natural draft at the stack entrance. Boiler Draft Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  56. 56. Forced draft: When air or flue gases are maintained above atmospheric pressure. Normally it is done with the help of a forced draft fan. Boiler Draft Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  57. 57. Induced draft: When air or flue gases flow under the effect of a gradually decreasing pressure below atmospheric pressure, in this case the system is said to operate under induced draft. In this case the stacks(chimneys) provide sufficient natural draft to meet the low draft loss needs. On the other hand, in order to meet higher pressure differentials the stacks are operating with draft fans simultaneously. Boiler Draft Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  58. 58. Balanced draft: When the static pressure is equal to the atmospheric pressure the system is referred to as the balanced draft. Draft is said to be zero in this system Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  59. 59. Air & Flue Gas System The air and gas systems are provided for force draft to the boiler for complete combustion of the fuel. The Gas Recirculation Fan increases the mass flow of air to maintain the hot reheat temperature. The flue gases going to the stack raise the inlet air temperature, ultimately increasing boiler efficiency. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  60. 60. Air & Flue Gas System SCAPH RAH GRF ESP Stack Boiler Flue Gases Flow Air Flow GRF RAH FDF outlet air Pressure 635 mmH2O Temp. 29.0 oC Flue Gas outlet gas Pressure 56 mmH2O Temp. 147 oC GRF outlet Pressure 339 mmH2O Flue gas Pressure 166 mmH2O Temp. 344 oC SCAPH RAH ESP Burners Wind Box Steam Drum Ash Hoppers SH SH SH RH SH SH ECO Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  61. 61. Boiler Drains & Vents System The water that is feed to the boiler contains impurities in the form of suspended solids and dissolved solids. A large portion of these impurities is left behind when the steam leaves the boiler. Some of these suspended impurities have tendency to settle down in the lowest part of the boiler. Others are light and float on the surface of the water. The operator must control the buildup of impurities, by injection of chemical into the feedwater and blowing down. Blowing down at a slower rate and over a longer period of time reduces the concentration more effectively than is possible by opening wide the main blowdown valve. Therefore closer control and more accurate regulation of the blowdown is achieved. The continuous blowdown requires the use of the Blowdown Flash Tank where the high pressure water can be flashed into low pressure steam. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  62. 62. Vents are provided on different pressure parts of the Boiler. They are used during depressurizing, filling and charging the system. All drains and vents are manually operated and are used during startup and shutdown. • The purpose of this system is to vent and drain the Superheater, Reheater, Boiler drum, Economizer, Deaerator and Boiler convection pass during startup and shutdown activities of the Boiler as required. • To cool down the high temperature drains in the Blowdown Tank before sending the water to the waste water system. Boiler Drains & Vents System Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  63. 63. Use of Drains: Superheater Drains •During startup, these drain valves are opened to drain any buildup of water in the superheater. Water remaining in the superheater would restrict the flow of steam and cause the tubes to overheat. In addition, operating with the superheater drains cracked open, allows steam to circulate through the superheater tubes thus preventing excessive heat buildup. •During shutdown, these drain valves are usually opened to depressurize the superheaters. Reheater drains These drains are usually opened for depressurizing the Reheaters during shutdown. Drum level gauge drain This drain is usually opened when the gauge glass is required to place in service. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  64. 64. Use of Drains: Economizer inlet drain These drains are used for draining the boiler after shutdown. Lower convection pass header drain These drains are used for draining the boiler after shutdown. Downcomer header drains These drains are used for draining the boiler after shutdown or cycling the feedwater system during normal operation. Continuos Blowdown This arrangement is used to remove the silica & other impurities form the steam drum water. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  65. 65. Use of Vents: Drum vent • During depressurizing the boiler, open the vent at 2Kg. Pressure. • Keep this vent open during the following situations: • Boiler filling • Until steam pressure increase to >1.5Kg to prevent a rapid increase of drum pressure during startup. Superheater vents Keep these vents open until steam comes out of those during startup. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  66. 66. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Saba Power Plant
  67. 67. HRSG Auxiliary components: Complete boiler trim package ASME code piping Lined duct work/casing for high and low temperature and dirty gas applications Expansion joints Diverter valves Guillotine dampers with Zero-leakage sealed air system Silencers Duct burners Fuel trains/racks Combustion controls & burner management systems Blowdown tanks Deaerators and BFW pumps Feedwater economizers DA make up water pre-heaters Process heat exchangers Hoppers Structural steel Free-standing and self-supporting stacks SCR system CO catalyst Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  68. 68. Boiler auxiliaries have the following parts: •Forced draft fan (FDF). •Induced draft fan (IDF). •Recirculation fan (RCF). •Fan Dampers • Burners / Igniters and BMS (Burner Management System) • Atomizing Air or Steam System •Feed Water Tank & DA & Feed water heater • Feed water pump • Chemical Feed System • Seal Air Blower • Flame Scanner Cooling Blower • Fuel Handling System • ESP • Ash Handling System • Blowdown Tank • Service & Instrument Air System BOILER AUXILIARIES Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  69. 69. In figure gives a symbolic representation of the different boiler auxiliary equipment and their major interconnections. A brief note on various auxiliary equipment has been given in the following sections. BOILER AUXILIARIES Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Saba Power Plant
  70. 70. COAL BOILER AUXILIARIES
  71. 71. Boiler Draft Fans The largest fans in power plants deliver air to the burners (force draft fan, FD) and extract flue gas from the boiler (induced-draft fan, ID). Plants with flue gas desulfurization may have additional booster fans. Those large fans range from 1 to 18MWel and are usually built as axial fans. Their blades have an airfoil shape and the gas flow is controlled with variable pitch of the rotating blades. Axial fans have higher capital costs than centrifugal fans, and because of more numerous parts and complexity, they also require more maintenance. All other fans in power plants are usually smaller, and built as radial fans, also called centrifugal fans. The pressure and flow characteristics of radial fans are dependent on the orientation and shape of the fan blades, like backward-curved blades, straight ‘radial’ design, forward-curved blades. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Saba Power Plant
  72. 72. Boiler Draft Fans Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Forced Draft Fan Forced Draft fan supplies air at high speed to furnace during fuel combustion. It controls airflow and handles air at normal temperature. Forced Draft Fan has ability to work with high static pressure. . These fans are used to supply air during various industrial processes at high speed. The fans offered by us help in supplying fresh air by pulling out the air dust particles, with the help of chimneys.
  73. 73. FDF Suction Filters Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor FDF Suction Filters are used for provide clean air to boiler for good combustion, and this air passes through the tubular or regenerative air heater and to the wind box connecting duct which supplies the secondary air to wind boxes.
  74. 74. Boiler Draft Fans Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Induced Draft (ID) fans are used to create a vacuum or negative air pressure in a system or stack. Induced Draft Fan
  75. 75. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor FDF Inlet Damper Inlet guide vane control Motor and fan run with fixed speed. A solid gear may be used, since fan speed may be lower than motor speed. Flow is adjusted with the inlet guide vane position. The guide vane directs the gas into the same direction of rotation as the fan impeller, which reduces the fan flow. Inlet guide vane control is more efficient than inlet dampers due to reduced friction in creating the pre-swirl movement. Inlet damper control Motor and fan run with fixed speed. Flow is adjusted with the inlet damper position. The inlet damper directs the gas into the same direction of rotation as the fan impeller, which reduces the fan flow. Inlet damper control is less efficient than an inlet guide vane due to increased friction in creating the pre-swirl movement.
  76. 76. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor GRF (Gas Recirculation Fan) Gas Recirculation Fan (GRF) draw gas from a point between the economizer outlet and the air heater inlet and discharge it into the bottom of the furnace outlet. Recirculation gas introduced in the vicinity of the initial burning zone of the furnace is used for steam temperature control, while re circulated gas introduced near the furnace outlet is used for control of gas temperature. RH outlet steam temperature is normally controlled by regulating the gas recirculation flow. Increased flue gas flow over Reheater of the convection heating surfaces increases the heat absorption and RH temperature is increased. (GFR or FGR) acts to reduce NOx formation by reducing peak flames temperatures. In conventional applications.
  77. 77. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor GRF (Gas Recirculation Fan)
  78. 78. WINDBOX Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Saba Power Plant
  79. 79. Burners Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Saba Power Plant
  80. 80. Fuel Atomizing System Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  81. 81. Fuel Atomizing System Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  82. 82. Fuel Atomizing System Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  83. 83. Coal Fire Boiler Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Saba Power Plant
  84. 84. Coal Fire Boiler Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Saba Power Plant
  85. 85. Coal Fire Boiler Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Saba Power Plant
  86. 86. Boiler Feed Water Tank with Deaerator Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  87. 87. Boiler Feed Water Tank with Deaerator Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  88. 88. Flash Economizer Blowdown Separator Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Saba Power Plant
  89. 89. Boiler Feed Water Heaters Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Saba Power Plant
  90. 90. Boiler Feed Water Pump A boiler feedwater pump is a specific type of pump used to pump feedwater into a steam boiler. The water may be freshly supplied or returning condensate produced as a result of the condensation of the steam produced by the boiler. These pumps are normally high pressure units that take suction from a condensate return system and can be of the centrifugal pump type or positive displacement type. Boiler feedwater pumps are sometimes driven by large electric motors that operate with hydrodynamic bearings and mechanical seals. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  91. 91. Boiler Feed Water Pump Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  92. 92. Boiler Feed Water Pump Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  93. 93. Boiler Chemical Dosing System Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Saba Power Plant
  94. 94. Boiler Chemical Dosing System Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Saba Power Plant
  95. 95. Cooling Air Fans: Cooling air fans are used to cool the burners and surrounding equipment’s like flame detector, oil firing gun, gas burners. During normal operation, one (1) blower is kept in service and the other blower is on standby. The blower takes suction from atmosphere through an inlet filter and supplies filtered and pressurized air to all six burners for the cooling of the flame scanners and Main burners and Igniter gun sleeves. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  96. 96. Seal Air Fan basically functions as booster fan taking suction from primary air fan discharge (cold primary air before AH) boosting up the air pressure and supplying seal air to various sealing points. Seal Air Fan During normal operation one (1) Seal Air Blower is in service and the additional blower is on standby in order to supply an adequate amount of air for the sealing of the penthouse, superheater vestibule, GRF seals, Thermoprobe and soot blowers. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  97. 97. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Fuel Handling System
  98. 98. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Fuel Handling System Gas
  99. 99. Fuel Supply System Road Tankers Bay Rail Wagons Bay RFO Transfer Pumps Suction Strainers RFO Unloading Pumps RFO Unloading Pumps Suction Strainers RFO Transfer Pumps RFO Pressurizing Pumps Suction Strainers RFO Pressurizing Pumps RFO Burner Deck Suction Strainers RFO Discharge Heaters RFO Day Tank RFO Burners RFO Storage Tank-2 RFO Storage Tank-1 RFO Unloading direct to day tank & Recirculation Line RFO Return Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor RFO
  100. 100. Fuel System for Boiler Ignition HSD unloading Pumps Suction Strainers HSD Unlading Pumps HSD Pressurizing Pumps Suction Strainers Y type HSD Pressurizing Pumps HSD Strainers HSD Day Tank HSD Igniters HSD Road Tanker HSD Day Tank Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor HSD
  101. 101. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Fuel Handling System Coal
  102. 102. Fuel Handling System Biomass Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Saba Power Plant
  103. 103. ESP (Electrostatic Precipitator) Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Saba Power Plant
  104. 104. ESP (Electrostatic Precipitator) Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Saba Power Plant
  105. 105. Ash Handling System Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Saba Power Plant
  106. 106. Ash Handling System Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Saba Power Plant
  107. 107. Ash Handling System Vacuum Conveying System Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Saba Power Plant
  108. 108. Ash Handling System Vacuum Pneumatic Conveying System Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Saba Power Plant
  109. 109. Ash Handling System Clinker / Hydraulic Conveying System Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Saba Power Plant
  110. 110. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Safety Valve An important boiler fitting is the safety valve. Its function is to protect the boiler shell from over pressure and subsequent explosion.
  111. 111. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Safety Valve Many Different Types of Safety Valves are fitted to steam boiler plant, but generally they must all meet the following criteria: The ASME standard I and ASME standard VIII for boiler and pressure vessel applications and the ASME / ANSI PTC 25.3 standard for safety valves and relief valves provide the following definition. These standards set performance characteristics as well as defining the different types of safety valves that are used: ASME I valve - A safety relief valve conforming to the requirements of Section I of the ASME pressure vessel code for boiler applications which will open within 3% overpressure and close within 4%. It will usually feature two blowdown rings, and is identified by a National Board 'V' stamp.
  112. 112. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Safety Valve ASME VIII valve - A safety relief valve conforming to the requirements of Section VIII of the ASME pressure vessel code for pressure vessel applications which will open within 10% overpressure and close within 7%. Identified by a National Board 'UV' stamp. Low lift safety valve - The actual position of the disc determines the discharge area of the valve. Full lift safety valve - The discharge area is not determined by the position of the disc. Full bore safety valve - A safety valve having no protrusions in the bore, and wherein the valve lifts to an extent sufficient for the minimum area at any section, at or below the seat, to become the controlling orifice.
  113. 113. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Safety Valve Conventional safety relief valve - The spring housing is vented to the discharge side, hence operational characteristics are directly affected by changes in the backpressure to the valve. Balanced safety relief valve - A balanced valve incorporates a means of minimizing the effect of backpressure on the operational characteristics of the valve. Pilot operated pressure relief valve - The major relieving device is combined with, and is controlled by, a self-actuated auxiliary pressure relief device. Power-actuated safety relief valve - A pressure relief valve in which the major pressure relieving device is combined with, and controlled by, a device requiring an external source of energy.
  114. 114. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Safety Valve
  115. 115. Level Measurement Pressure Measurement Flow Measurement Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor
  116. 116. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor LOCAL MEASUREMENT Drum Level Gauge Glass The level of water in a steam boiler must be carefully controlled, to ensure good quality steam is produced safely, efficiently and at the correct pressure. In most cases, the simple gauge glass on the steam / water drum or boiler shell is used as the indicator. Many standards stipulate the provision of two gauge glasses. Arrangements are usually required to prevent a breakage from causing a hazard to the operator. The most common form of protection is a toughened glass screen to the front and sides of the water gauge glass. .
  117. 117. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor LOCAL MEASUREMENT Pressure Measurement Pressure gauges are used to determine: Steam Pressure Feedwater Pressure Oil Pressure Gas Pressure Draft Pressure Pressure may be recorded as gauge pressure or as absolute pressure. Gauge pressure is the pressure above that of the atmosphere. Absolute pressure is the pressure above zero pressure, equal to gauge pressure plus the atmospheric pressure. At sea level, atmospheric pressure is 14.7 psi. Pressure gauges include many pressure measurement devices including bellows, Bourdon tubes, capsule elements and diaphragm element gages; detailed form for analog or needle dial face gauges.
  118. 118. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor LOCAL MEASUREMENT Temperature Measurement Temperature Gauges are used to determine: Feedwater Temperature Oil Temperature Water Temperature Flue Gas Temperature Temperature gauges can be classified as either mechanical in design or electronic. Mechanical temperature gauges include bi- metallic or filled system design. A bi- metallic thermometer uses two dissimilar metals joined together. Since these metals are not the same their co-efficient of expansion will be different allowing the composite metal strip to bend in the direction of the metal with the lower co- efficient. This is predicable and repeatable and therefore can be scaled. Bi-metal temperature gauges are inexpensive and are commonly used in boiler applications.
  119. 119. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor LOCAL MEASUREMENT Fluid Flow Measurement Fluid characteristics and flow theory (including Bernoulli's theorem and Reynolds' numbers) are introduced and developed to provide basic metering theory and techniques. Different meter types, instrumentation and installation practice are also discussed.
  120. 120. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor LOCAL MEASUREMENT Flow Measurement Fluid characteristics and flow theory (including Bernoulli's theorem and Reynolds' numbers) are introduced and developed to provide basic metering theory and techniques. Different meter types, instrumentation and installation practice are also discussed. Many flow meters are based on the work of Daniel Bernoulli in the 1700s. Bernoulli's theorem relates to the Steady Flow Energy Equation (SFEE), and states that the sum of: Pressure energy, Kinetic energy and Potential energy P1 and P2 = Pressure at points within a system (Pa) u1 and u2 = Velocities at corresponding points within a system (m/s) h1 and h2 = Relative vertical heights within a system (m) ρ = Density (kg/m) g = Gravitational constant (9.81 m/s²) Bernoulli's equation ignores the effects of friction and can be simplified as follows: Pressure energy + Potential energy + Kinetic energy = Constant
  121. 121. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor LOCAL MEASUREMENT Steam Flow Measurement Most common method of steam metering is the traditional orifice and differential pressure transmitter technique. The main areas of concern with this type of measurement are the orifice plates susceptibility to wear introducing immediate inaccuracies, the relatively high pressure losses introduced into the system by the orifice plate and the small (typically 3:1) measuring range. The other major issue with this approach is the number of potential emission points, which could be as high as 30 depending on the configuration adopted. Another significant area of potential inaccuracy is the d/p transmitter itself. Even most so called smart d/p transmitters still utilize analogue sensing systems. The primary analogue sensor is very susceptible to drift caused by static pressures and high temperatures. These factors, coupled with the inaccuracies evident at low measuring ranges, can cause the overall performance of the metering installation to be highly suspect.
  122. 122. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor LOCAL MEASUREMENT Boiler Combustion Air Flow Measurement Boiler air flow (or air flow on a forced or balanced draft furnace) may be measured with a pitot tube, air foil section, or any calibrated flow restricting device located in the duct that leads from the forced draft fan to the windbox. (The windbox is the area behind the burner throats that supplies combustion air to the burners.) The differential across the windbox to the furnace can be as high as 25" H2O, but is not used because each time a register is adjusted, the flow relationship to delta P changes. On many boilers, air flow is the measured differential between the furnace inlet and the boiler outlet. This takes the differential of the hot gases as they flow through the furnace, across the convection section, and out the stack. In most cases, the differential ranges from 0.5 to 2.0 inches of water.
  123. 123. Prepared by: Mohammad Shoeb Siddiqui Sr. Shift Supervisor Saba Power Plant shoeb.siddiqui@sabapower.com shoeb_siddiqui@hotmail.com www.youtube.com/shoebsiddiqui

×