The document discusses turning gear operation during turbine startup and shutdown. During startup, the turning gear is used to roll out shaft deformations before runup and enable uniform prewarming. It operates long enough to reduce rotor eccentricity and meet minimum time requirements. Failure to adequately turn the rotor beforehand increases risks like rubbing damage and high vibrations during runup. During shutdown, the turning gear is needed to safely rotate the rotor for cooling and prevent excessive sagging or hogging. Its unavailability could lead to damage if the rotor is left stationary too long.
Centrifugal Pump Testing Standards - Presentation by ITTSahyog Shishodia
This presentation will give you all the details you need to know about Centrifugal Pumps Testing Standards.
It talks about API 610 , HI1.6, ISO 9906. What standards to follow while specifying pump testing and tolerances.
The document discusses the major components of steam turbines, including the casing, nozzles, blades, rotor, bearings, governors, and safety devices. It describes the functions of key parts like the nozzle, blades, governors, and oil pumps. It also classifies steam turbines based on the method of steam expansion, flow direction, final pressure, number of stages, and pressure. The document provides information on standards, parameter ranges, troubleshooting, and starting procedures for steam turbines.
The document provides an overview of the basic parts of a steam turbine, including turbine casings, rotors, blades, stationary blades and nozzles, shrouds, barring devices, seals, couplings, governors, and lubrication systems. It describes the materials, designs, and purposes of each part. The rotors can be disc-type or drum-type, depending on the turbine design. Blades are made of heat-resistant alloys and fastened via different methods. Seals prevent steam leakage and include shaft seals like carbon rings or labyrinth seals and blade seals such as labyrinth seals. Larger turbines use pressurized lubrication systems to lubricate bearings.
This document discusses the importance of instrument air quality for automation plant control systems. It describes how instrument air is used to operate pneumatic valves, pumps and other devices to keep the plant running properly. The key parameters for instrument air quality are dew point, oil content, particulates and temperature. It then examines different methods for drying instrument air including chemical drying, refrigeration and adsorption. Adsorption is identified as the most common method used, and it details how adsorption driers work using desiccants like activated alumina, silica gel and molecular sieves. The document presents the objectives and plan to design an air drier package to meet industrial specifications for instrument air quality in a plant.
Gas Turbine Training Power Point -SampleAli Rafiei
The document provides an overview of gas turbine evolution and components. It discusses the development of axial compressors and turbines from the 18th century ideas of John Barber and John Dumball. It then summarizes the key components of modern gas turbines, including compressors, combustion chambers, turbines, lubrication systems, and controls. Examples are given for Siemens SGT600 components like the compressor, combustion chamber, and control modes.
The document provides details about a case study of a 9.8 MW multi-stage steam turbine at Habib Sugar Mills in Nawabshah, Pakistan. It discusses the turbine specifications and common operational problems observed like rotor vibration and bearing failure. The causes of these problems are investigated like rotor imbalance, bearing misalignment, and excessive steam supply. Remedies are suggested such as regular maintenance, balancing the rotor, proper lubrication, and preventing contamination. The study aims to ensure proper turbine operation and investigate causes of failures to recommend solutions.
This document provides troubleshooting guidance for common air compressor issues. It lists various problems air compressors may experience such as failing to operate, excessive noise, knocking, insufficient pressure, oil consumption issues and more. For each problem, it identifies potential causes and recommended solutions to resolve the issue. The document serves as an informative guide for technicians to diagnose and repair air compressor faults.
This document provides instructions for performing pre-shutdown procedures on a kiln, including analyzing the condition of the kiln shell for distortions or runouts, checking the condition of tire and roller contact surfaces, and monitoring shell and tire temperatures. Key steps involve measuring and recording shell runout at various test points along the kiln to determine if sections of the shell need to be cut or replaced, ensuring tire and roller surfaces are flat and parallel before realignment work, and maintaining temperature logs to identify any dangerous temperature differences.
Centrifugal Pump Testing Standards - Presentation by ITTSahyog Shishodia
This presentation will give you all the details you need to know about Centrifugal Pumps Testing Standards.
It talks about API 610 , HI1.6, ISO 9906. What standards to follow while specifying pump testing and tolerances.
The document discusses the major components of steam turbines, including the casing, nozzles, blades, rotor, bearings, governors, and safety devices. It describes the functions of key parts like the nozzle, blades, governors, and oil pumps. It also classifies steam turbines based on the method of steam expansion, flow direction, final pressure, number of stages, and pressure. The document provides information on standards, parameter ranges, troubleshooting, and starting procedures for steam turbines.
The document provides an overview of the basic parts of a steam turbine, including turbine casings, rotors, blades, stationary blades and nozzles, shrouds, barring devices, seals, couplings, governors, and lubrication systems. It describes the materials, designs, and purposes of each part. The rotors can be disc-type or drum-type, depending on the turbine design. Blades are made of heat-resistant alloys and fastened via different methods. Seals prevent steam leakage and include shaft seals like carbon rings or labyrinth seals and blade seals such as labyrinth seals. Larger turbines use pressurized lubrication systems to lubricate bearings.
This document discusses the importance of instrument air quality for automation plant control systems. It describes how instrument air is used to operate pneumatic valves, pumps and other devices to keep the plant running properly. The key parameters for instrument air quality are dew point, oil content, particulates and temperature. It then examines different methods for drying instrument air including chemical drying, refrigeration and adsorption. Adsorption is identified as the most common method used, and it details how adsorption driers work using desiccants like activated alumina, silica gel and molecular sieves. The document presents the objectives and plan to design an air drier package to meet industrial specifications for instrument air quality in a plant.
Gas Turbine Training Power Point -SampleAli Rafiei
The document provides an overview of gas turbine evolution and components. It discusses the development of axial compressors and turbines from the 18th century ideas of John Barber and John Dumball. It then summarizes the key components of modern gas turbines, including compressors, combustion chambers, turbines, lubrication systems, and controls. Examples are given for Siemens SGT600 components like the compressor, combustion chamber, and control modes.
The document provides details about a case study of a 9.8 MW multi-stage steam turbine at Habib Sugar Mills in Nawabshah, Pakistan. It discusses the turbine specifications and common operational problems observed like rotor vibration and bearing failure. The causes of these problems are investigated like rotor imbalance, bearing misalignment, and excessive steam supply. Remedies are suggested such as regular maintenance, balancing the rotor, proper lubrication, and preventing contamination. The study aims to ensure proper turbine operation and investigate causes of failures to recommend solutions.
This document provides troubleshooting guidance for common air compressor issues. It lists various problems air compressors may experience such as failing to operate, excessive noise, knocking, insufficient pressure, oil consumption issues and more. For each problem, it identifies potential causes and recommended solutions to resolve the issue. The document serves as an informative guide for technicians to diagnose and repair air compressor faults.
This document provides instructions for performing pre-shutdown procedures on a kiln, including analyzing the condition of the kiln shell for distortions or runouts, checking the condition of tire and roller contact surfaces, and monitoring shell and tire temperatures. Key steps involve measuring and recording shell runout at various test points along the kiln to determine if sections of the shell need to be cut or replaced, ensuring tire and roller surfaces are flat and parallel before realignment work, and maintaining temperature logs to identify any dangerous temperature differences.
This document was produced as part of my final year project of training to obtain a petroleum engineering diploma.
The aim of this project is to make a comparative study between continuous and intermittent gas lift systems based on real data from an oil well in Algeria, and to choose the system best suited to increase the production of the well.
This study was carried out by a manual design using the method of “fixed pressure drop” for the continuous gas lift system and “fallback gradient” method for intermittent gas lift system.
We were able to determine at the end of this study that the system best suited to the current conditions of our well would be the intermittent gas lift system and we also proposed that it should be combine with the "plunger lift " system in order to increase the efficiency of the intermittent gas lift system by eliminating problems linked to the phenomenon of" fallback " thus increase the production of our wells.
The fan cylinder has several characteristics that influence airflow and fan efficiency. It provides a smooth transition for inlet air, guides air to the fan blades without disruption, and recovers velocity energy after the fan. The fan deck opening, structural rigidity, uniform tip clearance between the fan and cylinder, and gradual diameter increase for velocity recovery are important to maximize air through the cooling tower with minimum power usage. Improper sizing of these elements can significantly reduce performance.
This document discusses the importance of regular observation and walk-bys of cement rotary kilns to identify potential maintenance issues early. Taking proactive preventative maintenance is more cost effective than waiting for failures to occur. Trained observation of the kiln's mechanics and identifying small problems before they worsen can help reduce operating costs and maximize the kiln's lifespan. The document emphasizes learning the basic functions and components of the kiln to establish proper maintenance tasks through reinforced training.
This document provides an overview of the Ramagundam Thermal Power Station (RTPS) located in Telangana, India and describes the key components and processes within the plant. It discusses that RTPS is a 62.5 megawatt coal-fired power station owned by the government of Telangana. It receives coal via road and rail from Godavarikhani and uses water from the Godavari River. The document then describes the various divisions and components within the plant in detail, including the boiler, turbine, generator, cooling towers, feed pumps, economizer, air preheater, superheater, injector, steam separator, steam trap, coal handling plant, and ash handling plant
Increased Pulverizer Performance with Loesche’s High Efficiency Dynamic Class...LOESCHE
Loesche Energy Systems Ltd was contracted by an American Utility to supply a new dynamic classifier as a retrofit for the existing static classifier on a pulverizer of a Plant. This Plant is a coal-fired power station owned and operated by an American Utility in Kentucky. The Unit generates 800MWe net and was constructed in 1969.
First Published on www.greenbankenergy.com
1. Ankit Metals & Power Limited operates a sponge iron plant with two 350 TPD rotary kilns. One of the kilns developed cracks in the shell measuring up to 2000mm long and 25mm deep.
2. EWAC Alloys recommended welding the cracks with CPHFD 011 welding alloy. The cracks were welded from the outside in a double V groove technique with 3.15mm root passes and 4mm final layers.
3. After welding, testing confirmed the cracks were fully repaired with no remaining defects. Proper techniques like preheating, minimum current, and controlled cooling were followed to ensure a quality repair.
This document provides information about boilers, including their definition, principle of operation, types, parts, and auxiliaries. It defines a boiler as a closed vessel that converts water into steam using heat energy from fuel. The key points are:
- Boilers work by transferring heat from hot flue gases to water via convection, converting the water to high-pressure steam.
- Boilers are classified based on whether tubes contain water or fire (fire tube or water tube), number of tubes, furnace position, shell axis orientation, and circulation method.
- Boiler parts include mountings like the water level indicator, pressure gauge, and safety valve, as well as accessories like the feed pump
This document provides explanations and definitions related to rotary airlock valves. It discusses the key components of a rotary airlock including the rotor, vanes, pockets, housing, inlet and outlet ports. It explains the differences between open-end and closed-end rotors and how the number of vanes on a rotor can impact its sealing ability and pocket size. The document also discusses the two main causes of wear for rotary airlocks: surface drag abrasion caused by material being dragged between surfaces, and pneumatic assisted abrasion caused by pressurized air accelerating wear.
Steam jet ejectors provide vacuum using high-pressure steam as the motive fluid, requiring no external power source. They have no moving parts, making them reliable and easy to maintain. Ejectors work by accelerating steam through a converging-diverging nozzle, which entrains the suction fluid and recompresses it at an intermediate pressure through a diffuser. Ejectors can be single or multi-stage, with condensers used to improve efficiency, and are well-suited for applications that require vacuum where steam is readily available such as drying and distillation.
Feeders are used to transport materials or products in manufacturing and assembly applications. Common types of feeders include rotary, vibratory, screw, apron, bowl, and volumetric/gravimetric screw feeders. Silos are structures used for storing bulk materials like grains and operate through tower, bunker, and bag configurations. Tower silos can be concrete, metal, or other materials and use automated loading/unloading while bunker silos are low trenches with covers and bag silos are portable and temporary.
Pressure swing adsorption is a process that uses selective adsorption to separate gas mixtures. It works by passing a gas mixture through an adsorbent bed that attracts some gases more than others under pressure. When pressure is reduced, the adsorbed gases are released. Using two beds and alternating pressures allows for continuous gas production. Common adsorbents like zeolites and activated carbon can separate gases like oxygen from air or hydrogen sulfide from hydrocarbon streams. Pressure swing adsorption has various industrial applications such as oxygen production, hydrogen purification, and nitrogen generation.
The kiln was running normally except for a period in February when it was shut down due to an issue. Inspections found diesel oil in the main burner's gas inlet and increased wear on support rollers at station 3. Temperature measurements of bearings and pinions were within acceptable limits and the spray pattern for lubrication systems was good. Recommendations included grinding support rollers at station 3 and repairing the kiln shovel during the next shutdown.
The document discusses maintenance procedures for rotary kilns, including checking and adjusting the kiln alignment using benchmarks, ensuring proper contact between rollers and riding rings, addressing issues like shell warping, and inspecting the gear and pinion alignment. Key steps include establishing an offset centerline to check alignment, adjusting rollers as needed to align the shell centerline, checking for riding ring runout, adjusting rollers to avoid excessive thrust, and maintaining proper mesh between the main gear and pinion. Regular maintenance is important to prevent problems and excessive wear.
This document summarizes Schaeffer Precision Alignment's laser tracker services for inspecting steam turbines. They have experience inspecting hydro, gas, and steam turbines for over 260 clients. Their laser tracker technology allows precise inspection and alignment of individual turbine components. Inspections can locate components, monitor movement over time, and ensure reinstallation within tight tolerances. Schaeffer Precision Alignment provides a comprehensive solution for precision turbine maintenance and inspection.
This document summarizes the key components and operation of a gas turbine located at the Panipat Refinery. It includes 5 gas turbines made by BHEL/GE that are MS 6000 single shaft design units with a base load capacity of 30.77 MW each. The major components discussed include the compressor, combustors, turbine section, casings, bearings, and cooling/sealing systems. It also provides details on the basic principles of how a gas turbine works by continuously drawing in air, compressing it, adding fuel to increase its energy, directing the high pressure gas to expand through a turbine, and exhausting the low pressure gas.
The boiler system comprises a feed-water system, steam system, and fuel system. The feed-water system supplies treated water to the boiler and regulate it automatically to meet the steam demand. Various valves and controls are provided to access for maintenance and monitoring.
The document provides details on 14 mechanical seal piping plans ranging from single seal designs (Plans 01-14, 21-23, 31-32, 41) to dual seal designs (Plans 52-54) and specialized designs including quench seals (Plans 62, 65), gas seals (Plans 72, 74-76), and unpressurized and pressurized buffer fluid circulation systems. Each plan is accompanied by descriptions of its key features and considerations for preventative maintenance.
Casing Centralizers: Are We Using Too Many or Too Few?pvisoftware
Casing centralization is one of the key elements to ensure the quality of a cementing job by preventing mud channeling and poor zonal isolation. Centralizer manufacturers likely want to increase the demand for centralizers. However, operators on the other hand, may wonder: “Should we use that many?” Download this white paper to learn how to place centralizers that gives a satisfactory standoff, an ease of field installation, and good economics.
This 3 sentence document summary provides the essential information about the original document:
The original document discusses a turning gear mechanism for a steam turbine that was prepared by Md. Hasib Reza with an ID# of 1967. It mentions barring gear being disengaged and includes the identifier 3ZLH114A.
This document was produced as part of my final year project of training to obtain a petroleum engineering diploma.
The aim of this project is to make a comparative study between continuous and intermittent gas lift systems based on real data from an oil well in Algeria, and to choose the system best suited to increase the production of the well.
This study was carried out by a manual design using the method of “fixed pressure drop” for the continuous gas lift system and “fallback gradient” method for intermittent gas lift system.
We were able to determine at the end of this study that the system best suited to the current conditions of our well would be the intermittent gas lift system and we also proposed that it should be combine with the "plunger lift " system in order to increase the efficiency of the intermittent gas lift system by eliminating problems linked to the phenomenon of" fallback " thus increase the production of our wells.
The fan cylinder has several characteristics that influence airflow and fan efficiency. It provides a smooth transition for inlet air, guides air to the fan blades without disruption, and recovers velocity energy after the fan. The fan deck opening, structural rigidity, uniform tip clearance between the fan and cylinder, and gradual diameter increase for velocity recovery are important to maximize air through the cooling tower with minimum power usage. Improper sizing of these elements can significantly reduce performance.
This document discusses the importance of regular observation and walk-bys of cement rotary kilns to identify potential maintenance issues early. Taking proactive preventative maintenance is more cost effective than waiting for failures to occur. Trained observation of the kiln's mechanics and identifying small problems before they worsen can help reduce operating costs and maximize the kiln's lifespan. The document emphasizes learning the basic functions and components of the kiln to establish proper maintenance tasks through reinforced training.
This document provides an overview of the Ramagundam Thermal Power Station (RTPS) located in Telangana, India and describes the key components and processes within the plant. It discusses that RTPS is a 62.5 megawatt coal-fired power station owned by the government of Telangana. It receives coal via road and rail from Godavarikhani and uses water from the Godavari River. The document then describes the various divisions and components within the plant in detail, including the boiler, turbine, generator, cooling towers, feed pumps, economizer, air preheater, superheater, injector, steam separator, steam trap, coal handling plant, and ash handling plant
Increased Pulverizer Performance with Loesche’s High Efficiency Dynamic Class...LOESCHE
Loesche Energy Systems Ltd was contracted by an American Utility to supply a new dynamic classifier as a retrofit for the existing static classifier on a pulverizer of a Plant. This Plant is a coal-fired power station owned and operated by an American Utility in Kentucky. The Unit generates 800MWe net and was constructed in 1969.
First Published on www.greenbankenergy.com
1. Ankit Metals & Power Limited operates a sponge iron plant with two 350 TPD rotary kilns. One of the kilns developed cracks in the shell measuring up to 2000mm long and 25mm deep.
2. EWAC Alloys recommended welding the cracks with CPHFD 011 welding alloy. The cracks were welded from the outside in a double V groove technique with 3.15mm root passes and 4mm final layers.
3. After welding, testing confirmed the cracks were fully repaired with no remaining defects. Proper techniques like preheating, minimum current, and controlled cooling were followed to ensure a quality repair.
This document provides information about boilers, including their definition, principle of operation, types, parts, and auxiliaries. It defines a boiler as a closed vessel that converts water into steam using heat energy from fuel. The key points are:
- Boilers work by transferring heat from hot flue gases to water via convection, converting the water to high-pressure steam.
- Boilers are classified based on whether tubes contain water or fire (fire tube or water tube), number of tubes, furnace position, shell axis orientation, and circulation method.
- Boiler parts include mountings like the water level indicator, pressure gauge, and safety valve, as well as accessories like the feed pump
This document provides explanations and definitions related to rotary airlock valves. It discusses the key components of a rotary airlock including the rotor, vanes, pockets, housing, inlet and outlet ports. It explains the differences between open-end and closed-end rotors and how the number of vanes on a rotor can impact its sealing ability and pocket size. The document also discusses the two main causes of wear for rotary airlocks: surface drag abrasion caused by material being dragged between surfaces, and pneumatic assisted abrasion caused by pressurized air accelerating wear.
Steam jet ejectors provide vacuum using high-pressure steam as the motive fluid, requiring no external power source. They have no moving parts, making them reliable and easy to maintain. Ejectors work by accelerating steam through a converging-diverging nozzle, which entrains the suction fluid and recompresses it at an intermediate pressure through a diffuser. Ejectors can be single or multi-stage, with condensers used to improve efficiency, and are well-suited for applications that require vacuum where steam is readily available such as drying and distillation.
Feeders are used to transport materials or products in manufacturing and assembly applications. Common types of feeders include rotary, vibratory, screw, apron, bowl, and volumetric/gravimetric screw feeders. Silos are structures used for storing bulk materials like grains and operate through tower, bunker, and bag configurations. Tower silos can be concrete, metal, or other materials and use automated loading/unloading while bunker silos are low trenches with covers and bag silos are portable and temporary.
Pressure swing adsorption is a process that uses selective adsorption to separate gas mixtures. It works by passing a gas mixture through an adsorbent bed that attracts some gases more than others under pressure. When pressure is reduced, the adsorbed gases are released. Using two beds and alternating pressures allows for continuous gas production. Common adsorbents like zeolites and activated carbon can separate gases like oxygen from air or hydrogen sulfide from hydrocarbon streams. Pressure swing adsorption has various industrial applications such as oxygen production, hydrogen purification, and nitrogen generation.
The kiln was running normally except for a period in February when it was shut down due to an issue. Inspections found diesel oil in the main burner's gas inlet and increased wear on support rollers at station 3. Temperature measurements of bearings and pinions were within acceptable limits and the spray pattern for lubrication systems was good. Recommendations included grinding support rollers at station 3 and repairing the kiln shovel during the next shutdown.
The document discusses maintenance procedures for rotary kilns, including checking and adjusting the kiln alignment using benchmarks, ensuring proper contact between rollers and riding rings, addressing issues like shell warping, and inspecting the gear and pinion alignment. Key steps include establishing an offset centerline to check alignment, adjusting rollers as needed to align the shell centerline, checking for riding ring runout, adjusting rollers to avoid excessive thrust, and maintaining proper mesh between the main gear and pinion. Regular maintenance is important to prevent problems and excessive wear.
This document summarizes Schaeffer Precision Alignment's laser tracker services for inspecting steam turbines. They have experience inspecting hydro, gas, and steam turbines for over 260 clients. Their laser tracker technology allows precise inspection and alignment of individual turbine components. Inspections can locate components, monitor movement over time, and ensure reinstallation within tight tolerances. Schaeffer Precision Alignment provides a comprehensive solution for precision turbine maintenance and inspection.
This document summarizes the key components and operation of a gas turbine located at the Panipat Refinery. It includes 5 gas turbines made by BHEL/GE that are MS 6000 single shaft design units with a base load capacity of 30.77 MW each. The major components discussed include the compressor, combustors, turbine section, casings, bearings, and cooling/sealing systems. It also provides details on the basic principles of how a gas turbine works by continuously drawing in air, compressing it, adding fuel to increase its energy, directing the high pressure gas to expand through a turbine, and exhausting the low pressure gas.
The boiler system comprises a feed-water system, steam system, and fuel system. The feed-water system supplies treated water to the boiler and regulate it automatically to meet the steam demand. Various valves and controls are provided to access for maintenance and monitoring.
The document provides details on 14 mechanical seal piping plans ranging from single seal designs (Plans 01-14, 21-23, 31-32, 41) to dual seal designs (Plans 52-54) and specialized designs including quench seals (Plans 62, 65), gas seals (Plans 72, 74-76), and unpressurized and pressurized buffer fluid circulation systems. Each plan is accompanied by descriptions of its key features and considerations for preventative maintenance.
Casing Centralizers: Are We Using Too Many or Too Few?pvisoftware
Casing centralization is one of the key elements to ensure the quality of a cementing job by preventing mud channeling and poor zonal isolation. Centralizer manufacturers likely want to increase the demand for centralizers. However, operators on the other hand, may wonder: “Should we use that many?” Download this white paper to learn how to place centralizers that gives a satisfactory standoff, an ease of field installation, and good economics.
This 3 sentence document summary provides the essential information about the original document:
The original document discusses a turning gear mechanism for a steam turbine that was prepared by Md. Hasib Reza with an ID# of 1967. It mentions barring gear being disengaged and includes the identifier 3ZLH114A.
The Turning over Mechanism Designed for Rehabilitation Nursing BedIJRES Journal
According to the requirements of turning over function of the nursing bed in this paper, the actual
situation of body turning over was analyzed and a new turning over mode was introduced based on the principle of
normal pressure driving. And the segmentation model of turning over bed frame is given, the design of nested bed
frame and the transmission mechanisms have the capability of force adaption and driving switch were completed
based on the requirements of auxiliary nursing. The relationship between the displacement of driving block and
turning angle is analyzed. The turning over function with fixed angle was realized by using the middle frames and
side frames. The results show that this turning over mechanism has practical significance for enhancing comfort
when turning over and improving the efficiency of rehabilitation.
The document provides instructions for starting up boilers from a cold state to produce steam. Preparatory steps include starting cooling water systems, filling compressed air cylinders, and checking fuel tanks. To replenish the boiler with feed water, blow-off valves are opened and the boiler is filled via an economizer bypass line. Once full, the economizer bypass is closed and main feed water valves are opened. Sea water flow through the main condenser is started to complete preparations before lighting the boiler burners.
The document provides details about the cooling and sealing system of a 247MVA turbo generator. It describes the generator specifications including rating, connection type, phases, rated speed, and insulation class. It then summarizes the need for generator cooling using hydrogen gas and water to minimize heat and ensure uniform temperature distribution. The rotor and stator cooling systems are explained along with specifications. Finally, the generator sealing system is outlined, which uses seal oil to prevent hydrogen leakage and maintain differential pressure between the oil and hydrogen.
The document discusses gas turbine components and operation. It describes the main parts of a gas turbine as the compressor, combustion chamber, and turbine. The compressor draws in and pressurizes air, which is then heated in the combustion chamber by adding and burning fuel. The high-energy combustion gases expand through the turbine, which drives the compressor and generates power. Startup procedures are discussed, including the use of blow-off valves to relieve compressor pressure and prevent surge during initial acceleration.
Steam turbines work by converting the energy of expanding steam into rotational motion. They have several key components and come in two main types: impulse and reaction. Impulse turbines use nozzles to direct high velocity steam onto turbine blades for impulse, while reaction turbines utilize both fixed and moving blades to expand steam. Common problems in steam turbines include stress corrosion cracking, corrosion fatigue, thermal fatigue, and pitting due to chemical attack from corrosive elements in the steam. Proper lubrication and preventing blade deterioration are important for optimizing steam turbine performance and lifespan.
This document discusses the key aspects of a 134 MW steam turbine. It begins by defining a steam turbine as a device that extracts thermal energy from pressurized steam and converts it into mechanical energy. It then provides specific design data for a 134 MW turbine, including its rated output, speed, steam conditions, number of extractions and stages. The document goes on to classify turbines based on their steam flow, type of energy conversion, compounding, cylinder arrangement, and exhaust conditions. It describes impulse, reaction, and combined impulse-reaction turbines as well as tandem and cross-compound cylinder arrangements.
Pre commissioning steam turbines load trialNagesh H
The document discusses pre-commissioning and commissioning activities for a steam turbine. Pre-commissioning includes steam blowing of lines, condenser testing like leak and vacuum drop tests, checking bearing clearances and dumps, setting throttle valves, and verifying safety trips. Commissioning procedures cover starting the turbine in solo run and load run modes while monitoring vibration levels and other parameters. Load trial data is collected and actual steam consumption is compared to projected values, with correction factors applied. Problems faced on site included low dump values due to nozzle chest welding issues and high CEP current due to pump-motor misalignment.
The document discusses steam turbines, including their basic components and operating principles. It describes the main types of steam turbines such as condensing, extraction, and reheat turbines. It also discusses the key parts like nozzles, blades, bearings, seals, monitoring systems, and control valves. The final section provides an overview of the typical start-up procedure for a steam turbine, including lubrication, turning, control system checks, and testing of valves before admitting steam.
Best ppt on thermal power station workingRonak Thakare
The document provides an overview of thermal power generation and the key components involved. It discusses how chemical energy from fuel is converted through various processes into electrical energy. The main components that enable this conversion are the boiler, turbine, and generator. Steam generated in the boiler powers the turbine, which spins the generator's rotor to produce electricity via electromagnetic induction. The turbine has high, intermediate, and low pressure sections to efficiently extract energy from the steam.
This document provides assembly instructions and a user manual for a 125cc 2-stroke engine. It includes sections that describe the engine features and specifications, instructions for installing the engine on a chassis, operating the engine, and basic maintenance procedures. Diagrams and lists of included parts are also provided.
Caterpillar Cat 277D MULTI TERRAIN LOADER (Prefix FMT) Service Repair Manual ...f8seodkdmdmed3
The document provides instructions for removing and installing various engine components on a 277D Multi Terrain Loader, including:
1) Removing and installing the diesel particulate filter, which requires disconnecting harness assemblies, removing mounting bolts, and using two people.
2) Removing and installing the inlet manifold, which involves disconnecting hoses and tubes and removing mounting bolts.
3) Procedures for removing and installing inlet and exhaust valve springs safely, which requires using special tools to compress the springs at top dead center.
Caterpillar Cat 277D MULTI TERRAIN LOADER (Prefix FMT) Service Repair Manual ...f8usejkdmmd8i
The document provides instructions for removing and installing various engine components on a 277D Multi Terrain Loader, including:
1) Removing and installing the diesel particulate filter, which requires disconnecting harness assemblies, removing mounting bolts, and using two people.
2) Removing and installing the inlet manifold, which involves disconnecting hoses and tubes and removing mounting bolts.
3) Procedures for removing and installing inlet and exhaust valve springs safely, which requires using special tools to compress the springs at top dead center.
Caterpillar Cat 277D MULTI TERRAIN LOADER (Prefix FMT) Service Repair Manual ...ze6074xunong
This service manual provides instructions for repairing and maintaining a 277D Multi Terrain Loader with a C3.3B engine. It includes procedures for removing and installing components like the diesel particulate filter, inlet manifold, valve springs, valve guides, and more. Technicians are advised to follow all safety precautions when handling hot or pressurized parts and to use the recommended tools for each job. Torque specifications are provided where applicable.
Caterpillar Cat 277D MULTI TERRAIN LOADER (Prefix FMT) Service Repair Manual ...tengtui535
This service manual provides instructions for repairing and maintaining a 277D Multi Terrain Loader with a C3.3B engine. It includes procedures for removing and installing components like the diesel particulate filter, inlet manifold, valve springs, valve guides, and more. Technicians are advised to follow all safety precautions and use the recommended tools when servicing parts. Torque specifications are provided for reinstalling components.
Caterpillar Cat 277D MULTI TERRAIN LOADER (Prefix FMT) Service Repair Manual ...f8usejkddmmd
The document provides instructions for removing and installing various engine components on a 277D Multi Terrain Loader, including:
1) Removing and installing the diesel particulate filter, which requires disconnecting harness assemblies, removing mounting bolts, and using two people.
2) Removing and installing the inlet manifold, which involves disconnecting hoses and tubes and removing mounting bolts.
3) Procedures for removing and installing inlet and exhaust valve springs safely, which requires using special tools to compress the springs at top dead center.
Caterpillar Cat 277D MULTI TERRAIN LOADER (Prefix FMT) Service Repair Manual ...fjskemmd4r
This service manual provides instructions for repairing and maintaining a 277D Multi Terrain Loader with a C3.3B engine. It includes procedures for removing and installing components like the diesel particulate filter, inlet manifold, valve springs, valve guides, and more. Technicians are advised to follow all safety precautions when handling hot or pressurized parts and to use the recommended tools for each job. Torque specifications are provided where applicable.
Caterpillar Cat 277D MULTI TERRAIN LOADER (Prefix FMT) Service Repair Manual ...f7fujksekmdm8u
The document provides instructions for removing and installing various engine components on a 277D Multi Terrain Loader, including:
1) Removing and installing the diesel particulate filter, which requires disconnecting harness assemblies, removing mounting bolts, and using two people.
2) Removing and installing the inlet manifold, which involves disconnecting hoses and tubes and removing mounting bolts.
3) Procedures for removing and installing inlet and exhaust valve springs safely, which requires using special tools to compress the springs at top dead center.
Caterpillar Cat 277D MULTI TERRAIN LOADER (Prefix FMT) Service Repair Manual ...jfkksemmdmd
The document provides instructions for removing and installing various engine components on a 277D Multi Terrain Loader, including:
1) Removing and installing the diesel particulate filter, which requires disconnecting harness assemblies, removing mounting bolts, and using two people.
2) Removing and installing the inlet manifold, which involves disconnecting hoses and tubes and removing mounting bolts.
3) Procedures for removing and installing inlet and exhaust valve springs safely, which requires using special tools to compress the springs at top dead center.
Caterpillar Cat 277D MULTI TERRAIN LOADER (Prefix FMT) Service Repair Manual ...f8usjejkdmmd
This service manual provides instructions for repairing and maintaining a 277D Multi Terrain Loader with a C3.3B engine. It includes procedures for removing and installing components like the diesel particulate filter, inlet manifold, valve springs, valve guides, and more. Technicians are advised to follow all safety precautions when handling hot or pressurized parts and to use the recommended tools for each job. Torque specifications are provided where applicable.
Caterpillar Cat 277D MULTI TERRAIN LOADER (Prefix FMT) Service Repair Manual ...gvxq62414225
This service manual provides instructions for repairing and maintaining a 277D Multi Terrain Loader with a C3.3B engine. It includes procedures for removing and installing components like the diesel particulate filter, inlet manifold, valve springs, valve guides, and more. Technicians are advised to follow all safety precautions when handling hot or pressurized parts and to use the recommended tools for each job. Torque specifications are provided where applicable.
Caterpillar Cat 277D MULTI TERRAIN LOADER (Prefix FMT) Service Repair Manual ...fujskdiddkmdm3e
The document provides instructions for removing and installing various engine components on a 277D Multi Terrain Loader, including:
1) Removing and installing the diesel particulate filter, which requires disconnecting harness assemblies, removing mounting bolts, and using two people.
2) Removing and installing the inlet manifold, which involves disconnecting hoses and tubes and removing mounting bolts.
3) Procedures for removing and installing inlet and exhaust valve springs safely, which requires using special tools to compress the springs at top dead center.
Caterpillar cat 277 d multi terrain loader (prefix fmt) service repair manual...jjskefkskemik
This service manual provides instructions for removing and installing various engine components on a 277D Multi Terrain Loader, including the diesel particulate filter, inlet manifold, valve springs, valves, and valve guides. The procedures describe disconnecting hoses and sensors, removing mounting bolts, using specialty tools to compress springs, and reinstalling components in the reverse order of removal while following torque specifications. Safety precautions are provided to prevent injury when handling hot or pressurized parts.
Caterpillar cat 277 d multi terrain loader (prefix fmt) service repair manual...ufjjdkskemmd
This service manual provides instructions for removing and installing various engine components on a 277D Multi Terrain Loader, including the diesel particulate filter, inlet manifold, valve springs, valves, and valve guides. The procedures describe disconnecting hoses and sensors, removing mounting bolts, and installing components in the reverse order of removal while following torque specifications. Safety precautions are provided for hot and pressurized components.
Caterpillar cat 277 d multi terrain loader (prefix fmt) service repair manual...ufjjskekkmde
This service manual provides instructions for removing and installing various engine components on a 277D Multi Terrain Loader, including the diesel particulate filter, inlet manifold, valve springs, valves, and valve guides. The procedures describe disconnecting hoses and sensors, removing mounting bolts, and installing components in the reverse order of removal while following torque specifications. Safety precautions are provided for hot and pressurized components.
Caterpillar cat 277 d multi terrain loader (prefix fmt) service repair manual...fujsjfkkskefsme
This document provides instructions for removing and installing various engine components on a 277D Multi Terrain Loader, including the diesel particulate filter, inlet manifold, and inlet/exhaust valves. The procedures describe disconnecting hoses and sensors, removing mounting bolts, and replacing components in the reverse order of removal while following torque specifications. Safety precautions are provided for hot and pressurized components.
Mercury mariner outboard 80 hp service repair manualfujsjfejkskem
This document provides general specifications and maintenance instructions for Mercury outboard engines. It includes specifications like horsepower, fuel tank capacity, lubrication points and intervals. The document also provides instructions for tasks like cowl removal, filling the oil injection system, checking fluid levels, lubricating components, and treating an engine after submersion. Special submersion instructions are provided for salt water, if the engine was running, and for fresh water.
Mercury mariner outboard 115 hp service repair manualufjjjsefkskem
This document provides general specifications and maintenance instructions for Mercury outboard engines. It includes specifications like horsepower, fuel tank capacity, oil injection tank specifications. It also provides instructions for routine maintenance like cowl removal, filling the oil injection system, checking fluid levels, lubricating pivot points. The document provides this information for a range of Mercury outboard models from 70 to 115 horsepower.
Mercury mariner outboard 90 hp service repair manualfusjejfjsekfkem
This document provides general specifications and maintenance instructions for Mercury outboard engines. It includes specifications like horsepower, fuel tank capacity, oil injection tank specifications. It also provides instructions for routine maintenance like cowl removal, filling the oil injection system, checking fluid levels, lubricating pivot points. The document provides this information for a range of Mercury outboard models from 70 to 115 horsepower.
Mercury mariner outboard 90 hp service repair manualufjjjdfjkksekmme
This document provides general specifications and maintenance instructions for Mercury outboard engines. It includes specifications like horsepower, fuel tank capacity, oil injection tank specifications. It also provides instructions for routine maintenance like cowl removal, filling the oil injection system, checking fluid levels, lubricating pivot points. The document provides this information for a range of Mercury outboard models from 70 to 115 horsepower.
Mercury mariner outboard 90 hp service repair manual
Turning gear
1. APPROVAL ISSUE Course 234 - Turbine and Auxiliaries - Module Nine
NOlES & REFERENCES
Module 234-9
THE TURNING GEAR
OBJECTIVES:
After completing this module you will be able. to:
9.1 a) For each of the turbine operating states listed below, state the
purpose(s) of the turning gear operation:
i) During turbine stanup (2); ¢:>Page 2
ii) While shutting down the turbine (I). ¢:>Page 4
b) For each of the operating states listed in point (a), describe turn- ~ Pages 3 (startup),
ing gear operation, addressing the following points: and 4-5 (shtdown)
i) When the turning gear motor is started up / sbut down;
ii) When the turning gear is engaged to / disengaged from the
torbine generator rotor;
iii) The reason why during turbine runup the turning gear mo-
tor continues running for some time after the turning gear
has disengaged from the turbine genemtor rotor;
iv) The reason why during turbine rundown the turning gear
motor is started up some time before the turning gear is ac-
tually needed to rotate the turbine generator rotor.
c) For each of the operating states listed below, descnbe the ad-
verse consequences/operating concerns caused by failure to tum
the turbine generator rotor as required:
i) During turbine stanup (2); ¢:> Pages 3-4
ii) While shutting down the turbine (3). ¢:> Pages 5-6
9.2 Explain the major operational concern caused by excessive use of ¢:> Page 6
the turning gear.
9.3 a) i) State the general operator action that should be taken, to ¢:> Pages 7-8
protect the turbine, if the turning gear fails to start during a
turbine rundown.
ii) Explain how this action protects the turbine.
iii) Describe three alternate methods of turning the turbine rotor
that can be used under these operating circumstances.
Page 1
2. Course 234 - Turbine and Auxiliaries - Module Nine APPROVAL ISSUE
NOTES & REFERENCES
b) Assuming that the turbine rotor has been left stationary for too
Page 8 <=> long during the cooldown that foilows a turbine rundown:
i) State one important precaution that must be taken prior to
anempting to turn the rotor by the turning gear when it be-
comes available;
ii) Explain the reason why this precaution is necessary;
iii) State the required action if, as a result of this precaution,
the tumiIig gear must not be used.
•••
INSTRUCTIONAL TEXT
INTRODUCTION
In the turbine courses which you have taken so far, the function and struc-
ture of a typical turning gear as weil as the phenomena of tlIbine generator
shaft hogging and sagging are described. This general infonnation is sup-
plemented in this module with a detailed description of turning gear opera-
tion during turbine startup and shutdown. Effects of the turning gear una-
vailability while shutting down the turbine are also covered.
TURNING GEAR OPERATION DURING TURBINE
STARTUP
Obj. 9.1 a) i) <=> Purposes
The major purposes of turning gear operation during turbine startup are:
1. To rollout sbaft hogging or sagging before runup is begun.
As mentioned in the previous module, any attempt to run up the turbine
with an excessively deformed shaft is bound to fail because high vibra-
tion would sooner or later fOICe a turbine trip. Meanwhile, the turbine
generator·would be unnecessarily exposed to increased risk of damage
due to high vibration and/or rubbing.
2. To enable uniform prewarming of the turbine generator.
If the turbine generator were prewanned with the rotor held stationary,
rotor and casing hogging would develop due to thenna! stratification of
. the annosphere inside the machine as outlined in the earlier turbine
courses. This would make nmup impossible until the hogging is roiled
out.
Page 2
3. APPROVAL ISSUE Course 234 - Turbine and Auxiliaries - Module Nine
NOTES & REFERENCES
Operation
To achieve these two objectives, the turning gear is started early during unit ~ Obj. 9.1 b)
startup such that the turbine generator can spend enough time on turning
gear. In principle, the duration or tuming gear operation must be
enough to:
- Straighten up the turbine generator shaft such that the HP turhine rotor
eccentricity is within the acceptable limit, and
- Meet the additional tequirements (if any) tegarding the minimum time on
U1Dling gear that is necessary to equalize turbine casing temperature.
This allows us to make sure that the casing is straight, despite lack of in-
strumentation that would measure casing hogging or sagging.
The required. minimum time on turning gear varies from station to sta-
tion, teflecting the operating experience of the turbine manufacturer.
Usually, the minimum time depends on the duration of the preceding
shutdown during which the turbine generator rotor was left stationary,
and may reach up to 24 hOllIS.
When the turning gear is started up, its motor is energized and the turning
gear drive is engaged to the turbine generator rotor. Nonnally, the turning
gear is started manually. but in some new stations, this - along with many
other startup activities - can be done automatically by applOpriate DCC soft-
ware.
When turbine runup begins, the U1Dling gear disengages automatically as
soon as turbine speed stans increasing. The turning gear motor, however,
keeps running until turbine speed reaches a certain level· at which the motor • 100-1000 rpm. depending
switches off automatically. The extended period of motor operation is a on the station.
pnocaution taken to make sure the turning gear is available for proper turhine
shutdown, should the turbine runup have to be aborted.
Adverse consequences and operating concerns caused by ~ Obj. 9.1 c) i)
inadequate operation
Failure to U1Dl the turbine generator rotor long enough prior to runup causes
the following adverse consequences/operating concerns due to turbine gen-
erator operation with an excessively bowed rotor:
I. Increaaed risk of rubbing damage to turbine generator internals·. • Rubbing damage is de·
scribed in more detail in
Recall that at low speeds rubhing can go undetected because indicated module 234-.1.
bearing vibration can be misleadingly low despite the abnormal rotor
defonnation.
2. Increased turbine generator bearing vibrations.
As soon as speed is high enough, and particularly while passing
through a critical speed range, the vibrations can become abnormally
Page 3
4. Course 234 - Turbine and Auxiliaries - Module Nine APPROVAL ISSUE
NOTES & REFERENCES
high. They may force a turbine trip and, in ~he extreme case, damage the
machine.
SUMMARY OF THE KEY CONCEPTS
• During turbine startup, the turning gear is used in order to roU out shaft
defonnations before nmup begins, and to enable uniform ptewanning
of the turbine generator.
• To achieve these objectives, the turning gear is staned early during unit
startup. Its opetation is continued long enough to reduce the HP turbine
rotor eccentricity to a satisfactory level, and to meet any additional time
requirements as specified in the appropriate opetating manual.
• As soon as steam is 3dnUtted to the tmbine, causing its speed to in-
crease, the turning gear should disengage automatically from the turbine
generator shaft. The turning gear motor continues running until a cer~
lain turbine speed is reached. This ensores turning gear availability if
the turbine startup had to be aborted.
• Failure to use the turning gear as required during turbine startup may re-
sult in rubbing damage during nmup. Very high bearing vibrations may
force a turbine 1rip, and even damage the machine.
TURNING GEAR OPERATION WHILE SHUTTING
DOWN THE TURBINE
Obj. 9.1 a) ii) ~ Purpose
When the turbine generator is being shut down. the turning gear is used to
prevent excessive bogging of the turbine rotor and casing. This would
happen if. following the turbine rundown, the rotor were left stationary
while the turbine is still hot.
Obj. 9.1 b) ~ Operation
During turbine rundown. the turning gear motor should automatically
switcb 00 at the same turbine speed at whiCh it turns off during turbine run-
up. The turning gear, however, remains disengaged from the turbine gener-
• Down to 0-20 tpm. de- ator shaft until turbine speed has decreased enough·. The early startup of
pending on the station. the turning gear motor (at least sevetai minutes before the turning gear is ac-
tually needed) gives the operator time to respond, should the motor fail to
start This upset is discussed in detail later in the module.
After turbine speed bas decreased sufficiently, tbe turning gear is me-
chanically engaged to the turbine generatOr rotor. In most stations. this is
performed automatically by a special self-shifting clutch. In other stations,
Page 4
5. APPROVAL ISSUE Course 234 - Turbine and Auxiliaries - Module Nine
NOlES & REFERENCES
the rotor must come to a full stop, and then the turning gear is engaged man-
ually.
The turhine then remains on turning gear until the highest HP turbine
metal temperature has decreased to a certain level"'. At this low tem- ... Typically, lOO·150·C,
perature, the turbine rotor can be left stationary without causing excessive depending on the station.
hogging. Note that turbine cooldown to this temperature range may take up
to two days. When the cooldown is complete, the turning gear motor is
switched off, and the gear drive is disengaged from the turbine generator r0-
tor..
Adverse consequences and operating concerns caused by ~ Obj. 9.1 c) ii)
inadequate operation
Because turbine shaft and casing hogging is a fast process, it is important
that the turning gear start driving the turbine generator rotor with
no delay. In some stations, a delay as short as three minutes is considered
sufficient to be able to cause excessive hogging. Likewise, only sbort in-
terruptions in turning gear operation can be tolerated before the tur-
bine has cooled down suffteiently. These restrictions decrease with de-
creasing turbine temperature. The cooler the turbine, the smaller the
temperature gradients inside the machine, and hence, the potential for its
hogging is reduced.
Failure to tum the turbine generator rotor as described above can result 'in
the following adverse consequences/operating concerns due to excessive
hogging of the turbine rotor and casing:
I. The subsequent turbine startup would have to be delayed to give
the turbine enough time to cool down and straighten out.
The larger the hogging, the longer the delay during which the turbine
generator remains unavailable for service. possibly resulting in loss of
production.
2. Damage to turbine seals, and possibly bearings, would likely hap-
pen if the radia1 clearances were closed and the rotor were turned despite
abnorma11y high resistance.
3. The turhine rotor may deform plastically due to excessive thermal
stresses.
Should this happen, the turbine could not be returned to service because
of excessive vibrations. The bowed rotor would have to be replaced
with a spare one (if any) and/or shipped to the manufacturer for repairs
or replacement. A long fmeed outage could result.
To keep it in the proper perspective, it must be stated that in CANDU
stations, as opposed to conventional thennal plants,chances tor
Page 5
6. Comse 234 - Turbine and Auxiliaries - Module Nine APPROVAL ISSUE
NOTES & REFERENCES
bogging tbat would produce plastic ileformation of tbe sbaft are
... 250-265'C cOmpared with very slim. This is due to the relatively low boiler stearn temperature*.
535·S6SoC. As a result, the maximum top-t~'t:xJqom temperature difference, that can
fonn wben the rotor is left stationary, is unlikely to be large enougb to
produce tbennal stresses exceeding the yield point of the rotor material.
Obj. 9.2 ~ EXCESSIVE USE OF THE TURNING GEAR'
In the preceding sections, you bave learned that the turning gear must be
used long enougb to avoid operational problems during turbine startup and
following rundown.
However, excessive operation of the turning gear should be avoided as this
may, in tbe long run, result in generator rotor ground faults caused by a
phenomenon known as copper dusting.
Copper dust can be fonned due to fretting of the generator rotor field wind-
... Refer to the appropriate ings against the slot walls·. At bigb turbine speeds, no fretting occurs be-
eleclrical course if you are cause the windings are finnly held in position against the slot wedge assem-
nol familiar with how the
generator rotor field wind· blies by the action of centrifugal force. However, at turning gear speed.
ings are held inside the centrifugal forces are negligible. Therefore, under their own weight, the
1"nln1"_
windings have a tendency to move radially inwards and outwards within the
slots once every rotor revolution. The movement of the windings will wear
away the copper, creating copper dust. Actual movement can happen if any
clearances are present between the windings and the slots. which is expect-
ed in machines that have been in service for several years. Naturally, sta-
tion specific differences in the generator rotor design can affect the rate at
which copper dusting can develop.
SUMMARY OF THE KEY CONCEPTS
• The purpose of turning gear operation while shutting down the turbine
is to prevent rotor hogging.
• If allowed to happen, this could delay the subsequent turbine startup un-
ti! the shaft bow is removed. Damage to turbine seals, and possibly
bearings, could happen if the radial clearances there were closed and the
rotor turned. In the worst - but extremely unlikely - case, the top-to-
bottom temperature gradient in the rotor might produce thermal stresses
sufficient to defonn the rotor plastically. A prolonged outage to repair!
replace the rotor would result
• To prevent excessive hogging while shutting down the turbine, the turn-
ing gear operates as follows. The motor is switched on as soon as the
turbine speed has decreased to a certain level. Engagement to the tur-
bine generator rotor occurs at least several minutes later, after turbine
speed has decreased to zero or nearly zero, depending on the station.
Page 6
7. APPROVAL ISSUE COUtBlII 234 - Turbine and Auxiliaries - Module Nine
NOTES & REFERENCES
The early startup of the turning gear motor gives the operator time to re-
spond, should the motor fail to start. Turning gear operation is contin-
ued until the highest turbine temperature has decreased to a certain limit
• Excessive use of the tmning gear is not recommended, mainly because it
promotes copper dusting in the generator rotor which can lead to genera-
tor ground faults.
You can now do assignment questions 1-4 <=>Pages 11-13
TURNING GEAR UNAVAILABILITY WHILE
SHUTllNG DOWN THE TURBINE
In this section. you will learn about:
- The action that the operator should take when the turning gear motor
fails to start during turbine rundown;
- Alternate methods of turning the turbine generator rotor;
- Actions that should he taken if the rotor is left Slationary for too long
during the cooldown that follows a turbine rundown.
As Slated earlier, during turbine rundown the turning gear motor should <=> Obj. 9.3 a)
stan at a certain turbine speed, at least several minutes earlier than the· turn-
ing gear is actually needed. This gives the operator enough time to respond
to failure of the motor to start.
Assuming that repeated attempts to start the motor fail, the operator
should arrange for an alternate method of tuming the turbine genera-
tor rotor. ideally, the arranged method should he ready for use when the
rotor has stopped. In no case, sbould the rotor be left stationary for
more than a few minules as it may be sufficient for excessive hogging to
form.
Depending on the station, one or two of the following alternate methods
of turning the turbine generator rotor. that can be applied quickly
enough to avoid excessive hogging, are available:
1. Handbarring by 1-2 men pushing a lever attached to the coupling he-
tween the turning gear motor aod the reduction box. Usually, the lever
has a ratchet mechanism which is engaged with teeth machiued on the
coupling periphery. When not used, the lever is hung on the turning
gear casing or nearby, so that it is readily available aod can he applied
quickly. Handbarring is the most common alternate method of turning
the turbine generator rotor.
2. A specialized electric or pneumatic tool which, when needed, can
he attached to the hack of the turning gear motor rotor. Thus, it can
drive the turbine generator rotor via the turning gear reduction box. The
tool should he stored as close to the turning gear as possible so that it
can be mounted quickly enough to prevent excessive turbine hogging.
Page 7
8. Course 234 - Turbine lind Auxiliariel _ Module Nine APPROVAL ISSUE
NOTES & REFERENCES
3. An auxiliary turning gear (available only in some units) which is in-
dependent from the main turning gear. As opposed to the other two
methods, the auxiliary turning gear can drive the turbine generator rotor
even when the main turning gear reduction box is unavailable.
Any of these methods can effectively protect the turbine from exces-
sive hogging because the hot rotor is not left stationary. While the turbine
speed that can be maintained is too small to ensure perfectly uniform cooling
of the turbine, continuous turning of the rotor minimizes hogging be-
. cause no excessive top-~bottom & can build. up in the rotor.
Obj. 9.3 b) <=> If, for some reason, the turbine rotor were left stationary for too
long· during its cooldown period, the possibility that excessive hogging
More than 5-30 minutes, may have developed must be taken into account. To avoid possible rub-
dependinj; on the station bing damage to turbine seals under these circumstances, precautions
llIId the highest HP tur-
bine metal temperature. must be taken prior to an attempt to turn the turbine rotor by the turning
gear when it becomes available.
This is achieved by handbarring the turbine rotor for one full turn
while checking for abnormaily high resistance to turning and/or monitoring
the HP turbine rotor eccentticity (depending on the station). If the handbar-
, Applicable limits should ring indicates that the rotor is bent excessively·, the turning gear must
be specified in the turning not be used.
gear system operating
manual. In most stations, the required action in these circumstances is to leave the
rotor stationary and let the turbine cool down to the temperature range
at which turning gear operation is normally tenninated. Then, the rotor
should be rotated by handbarring and checked for straightness, as described
in the paragraph above.
Note that as the turbine cools down, the hogging that has developed de-
creases due to temperature equalization. Normally, such cooldown is effec-
tive in reducing the hogging to a level at which the turning gear can be used
again. In the unlikely event that the turbine rotor could not be rotated by
handbarring following the cooldown period, the Technical Unit would have
to be infonned.
SUMMARY OF THE KEY CONCEPTS
• If the turning gear fails to start during turbine rundown, the operator
should arrange for an alternate method of turning the turbine generator
rotor.
o These methods typically include handbarring or use of a specialized
electric or pneumatic tool. In some units, an auxiliary turning gear is
also available.
• Any of these methods can maintain turbine speed that is sufficient to
prevent excessive turbine hogging.
Page 8
9. APPROVAL ISSUE COUflle 234 - Turbine and Auxiliaries - Module Nine
NOTES & REFERENCES
• IT the turbine rotOr were left stationary for too long before its cooldown
is complete, precautions must be taken prior to putting it on turning gear
when it beco~s available. This is necessary to prevent rubbing dam-
age to turbine seals because of the possibility that excessive hogging
may have developed.
• This is achieved by handbaning the turbine for one full turn while
checking for abnonnally high resistance to turning and/or excessive ec~
centticity of the HP turbine rotor, depending on the station.
• If the rotor is believed to be bent excessively, the turning gear must not
be used. In most stations, the required action is just to leave the turbine
rotor stationllI)' until the turbine has cooled down. This practice is very
likely to reduce the turbine hogging to a level at which the turning gear
can be safely used again.
You can now do assignment questions 5-6. {=> Pages 13-14
Page 9
10. APPROVAL ISSUE COOlIe 234 - Turbine utd Auxiliaries - Module Nine
NOTES. REFERENCES
ASSIGNMENT
I. During turbine startup:
a) The two objectives of turning gear operation are:
i)
ii)
b) If turbine ronup began prematurely, ie. not enough time on turn-
ing gear, the following adverse consequences/operating concerns
would result:
i)
ii)
c) To avoid these consequences, the turning gear should be operated
as follows:
i) It is started _
ii) It disengages from the turbine generator rotor when _ _
iii) Its motor isswitched off when _
2. While shutting down the turbine:
a) The PUIJlOse of turning gear operation is _
Page 11
11. COUl'lle 234 - Turbine and Auxiliaries - Module Nine APPROVAL ISSUE
NOTES & REFERENCES
b) Inadequate use of-the turning gear results in the following adverse
consequences/operating concerns:
i)
il)
iii)
c) The turning gear should be operated as follows:
i) It is stoned _
il) It is engaged to the turbine generator rotor when _
iii) It is shut down when _
3. a) The reason why during turbine ronup the turning gear motor con-
tinues running for some time after the tlnning gear has disengaged
from the turbine generator rotor is _
b) The reason why during turbine rundown the turning gear motor
is staneti up sorne time before the turning gear is actually needed
to drive the turbine generator rotor is _
Page 12
12. APPROVAL ISSUE Course 234 - Turbine and Auxiliaries - Module Nine
NOlES & REFERENCES
4. a) The major operational concern caused by excessive use of the
turning gear is that it promotes _
due to a phenomenon known as _
b) This phenomenon can develop as follows:
5. Suppose that during a turbine rundown the turning gear IOOtor failed to
start and it turned out that it will remain unavailable for some time. In
these circumstances:
a) To protect the turbine, the operator should _
b) Depending on the station, one or two of the following alternate
methods of turning the turbine generator rotor is I are available:
i) Method: _
Description: _
il) Method: _
Description: _
Page 13
13. Course 234 - Turbine and Auxiliaries - Module Nine APPROVAL ISSUE
NOTES & REFERENCES
iii) Method: _
Description: _
c) Any of these methods protects the turbine from _
_ _ _ _ _ _ because _
6. Assume that a hot turbine rotor has been left stationary for several min·
utes due to a temporary loss of the turning gear, and after this period
the turning gear is available for service again.
a) Prior to putting the turbine back on turning gear, the operator
should _
b) The reason why this precaution is taken is _
c) If it turned out, as a result of this precaution, that the turning gear
must not be used, the typical operating practice is _
Before you move on to the next module, review the objectives and make
sure that you can meet their requirements.
P<epuod by, J. J~•• ENTD
Revised by: J. Jung, ENTD
Revision date: June, 1994
Page 14