How does the generator seal oil system maintain its pressure over hydrogen pressure. The oil that flows across the outboard ring mixes with the bearing lube oil and returns to a lube oil. Eones involvement spans the life cycle of the generator, and often begins as part of an oems original scope of supply to the plant. As long as this seal oil pressure in the annular gap exceeds the gas pressure in the generator, no hydrogen can escape from the generator housing. Engineers modelled the hydrogen seal systems and used the simulated results to. The oil that flows across the outboard ring mixes with the bearing lube oil and returns to a lube oil tank. General description generator shaft seals are supplied with pressurized seal oil to prevent hydrogen escape at the shaft and the ingress of air in to the generator. Pipe plugs were installed in place of the spindles. Also, provides a trapvent system to prevent the release of hydrogen into the turbine generator lube oil system and building atmosphere. The technical support center was functional at 21 hours. The end shields are split on the horizontal centerline to facilitate their removal to enable assembly and disassembly of the rotor. Other systems integrate the seal oil system into the lube oil tank and use centrifugal pump. Seal oil is provided by a primary pump and a secondary pump which acts as a backup for the primary pump. Increase power output and reduce hydrogen seal oil system.
They seal the hydrogen in the machine where the rotor shaft emerges from the casing and shields. The hydrogen seal oil system pumps then supply oil to the generator seals at 8 psig above generator gas pressure. The main types of seals are thrust and journal seals. Generator seal oil system for hydrogen cooled turbo generator. Vented h2 to allow for securing h2 seal oil system 59 58. General electric systems technology manual chapter 9. Gas is prevented from escaping at the rotor shafts by a closedloop oil seal system. The generator is cooled with a hydrogen gas recirculation system using fans mounted on the generator rotor shaft. The heat absorbed by the gas is removed as it passes over. Hydrogen cools well, but safety is crucial power engineering. A small amount of gas is allowed to be vented from the seal oil enlargement tank, where the entrained air liberated from the seal oil is hopefully contained.
The seal oil system prevents gas from leaking out of the compressor case. Shaft seals and seal oil systems the seals are located in the end shields. The oil from the seals flows back to the turbine lube oil system for cooling and cleaning. Provide a seal between the generator housings and rotor shaft to maintain the pressurized hydrogen gas inside the generator.
A seal oil ring is used to avoid the contact between and ai. I have attached a pdf for you on instruments and why. Engineers modelled the hydrogen seal systems and used the simulated results to identify the of origin. Leistritz triple screw pumps, series l3nm, are responsible for the seal oil supply. Quizlet flashcards, activities and games help you improve your grades. Turbo gen services introduction function seals both ends of the generator shaft against hydrogen loss, as the generator. To ensure that the hydrogen gas does not escape the generator frame, a seal oil system is used. The unusual event was terminated on sunday, september 21, 2008 at 0409 hours.
Us20110231111a1 turbinegenerator hydrogen seal oil. The seal oil that flows into the hydrogen side of the seal area is generally passed to a vessel known as an enlargement tank. A system provided to remove air from the seal oil into the hydrogen side of the generator seal is popularly called a scavengingpurging system. Our critical gas auxiliary systems are designed for use with scavenging or vacuumtype seal oil configurations. Given a simplified diagram of a typical generator hydrogen seal oil system. The solution the major source of water in the turbine generator lubricating oil is water from poor steam seals on the turbine. Because of the high thermal conductivity and other favorable properties of hydrogen. Precommissioning checks and tests, detailed tests and commissioning procedures and instructions for all electrical equipment. Understanding, diagnosing, and repairing leaks in watercooled generator stator windings ge power systems. A system supplying oil to the seal plates of a generator.
How well the armature winding of a generator is cooled has a significant influence on the overall size of a synchronous generator. This explain the process of working of seal oil system in generator. Steam turbinegenerator overhaul and inspection guidelines. This is necessary to eliminate hydrogen contamination by air ingress in the seal oil, which is forced to flow along the shaft toward the hydrogenfilled generator. Turbine generator lubricating oil and the hydrogen seal oil must be analyzed for moisture content down to levels of 10 ppm 0. Control and oil system the relation of the various elements which comprise the complete governing or control system, is shown diagramatically in figure 1. Each hydrogen cooled generator is served by a main and auxiliary seal oil pump driven by an ac motor. Shaft seals and seal oil systems electric equipment. A main generator fire was caused by a failure of the hydrogen seal. Gain a thorough understanding of all precommissioning checks and tests, and all commissioning. Range includes but is not limited to purpose, methods of generator cooling, comparison of air and hydrogen cooled generators, efficiency losses, flow paths, temperature controls.
A hydrogen cooled generator having a system for diagnosing problems associated with a seal oil system. Under normal operating conditions a portion of the seal oil supplied by either pump is diverted through a bypass line so that only a predetermined amount of oil actually flows to the seal plates. What system directly cools the hydrogen in the generator. Included is a shaft having a turbine end and a collector end. Lube oil systems are generally considered under the turbine auxiliary systems and thus not typically included in generator maintenance. Ge hydrogen cooled 3d generator course overview duration. Seal oil system of generator in thermal power plant pump. The seal oil system may be a completely separate oil system, however in most cases it is apart of the compressor main lube oil system. Engineers modelled the hydrogen seal systems and used the simulated results to identify the case of their system trips. Steam turbine generator overhaul and inspection guidelines epri product number 10144.
These systems require auxiliary equipment such as pumps, regulators, filters, and so on for proper operation. With the use of hydrogen, a seal system had to be developed for the generator rotor shaft. This system keeps hydrogen gas from leaking out of the generator frame. Generator, unit hydrogen, seal oil, stator coolant, demin. Purpose of the generator h2 seal oil system the flow path of the following.
What is the normal operating pressure at the seals of the seal oil. There is also an emergency dc motor driven pump to provide the critical oil in the event of a turbine trip where ac power is not available. Ger3751a understanding, diagnosing, and repairing leaks. Leistritz seal oil pump generator hydrogen cooled generators require seal oil for their rotating shafts. Several auxiliary systems are used to condition and circulate the water and hydrogen used for cooling and keep the shaft seals supplied with oil. It is expected that the entrained air liberated from the seal oil, along. In order to safely and effectively employ hydrogen for generator.
Seal oil system of generator in thermal power plant free download as powerpoint presentation. Under these circumstances, the pressure differential provides the greatest drive for water to be forced into the groundwall insulation. Hydrogen leaks occur at the generator bearings and shaft seals, in the seal oil supply system and from the hydrogen supply piping, mechanicals and puritypurging cabinet. The shift manager initiated the emergency plan based on the fire in the protected area. The purpose of the seal oil system is to keep the compressed gas from entering the bearing assembly and escaping from the compressor to the atmosphere. Engineers modelled the hydrogen seal systems and used the simulated results to identify the case of their system.
Gek 107241 shaft sealing system 7h2 and 7fh2 generators. Combined cycle power plant simple cycle power plant fuel, lube, and seal oil supply system. For example, the westinghouse hydrogen seal oil system has an air side and a hydrogen side oil pressure line, each drawing oil from the main turbine lube reservoir. How would you know if your hydrogen purity is going down and what. Generator seal oil system free download as pdf file. Separate pumps are used to feed seal oil to the air and hydrogen sides figure 2. Most hydrogen cooled generator are incorporate the seal oil system, just because to avoid the contact between and air and hydrogen generally pressure of hydrogen in generator around 4bar. Generator hydrogen seal oil system must be in operation any time there is hydrogen or co2 in the generator casing.
However, even if the generator is not pressurized with hydrogen, seal oil must be supplied to the seals prior to placing the unit on the turning gear as the oil lubricates and cools the seals. In some plants, one may find an elaborate hydrogen cooling system panel where all hydrogen controls are located. Since the hydrogen seal oil system has parallel cartridge filters located downstream of the cuno filter, the cuno filter was returned to service without internal components. Title operate generator cooling and seal oil systems from. Gek 107241 shaft sealing system 7h2 and 7fh2 generators author. Each hydrogen cooled generator is served by a main and auxiliary seal. The adequacy of your plants protection system should be assessed for completeness in accordance with nfpa. Unit 4 hydrogen seal oil stephen ford simulator training instructor mec. Range includes but is not limited to function of seal oil, seal construction.
A hydrogen cooled turbo generator is a turbo generator with gaseous hydrogen as a coolant. List and briefly explain six operational requirements of the generator hydrogen seal oil system. Unit 1 cook nuclear plant turbine event status report. Vacuum values trending toward higher end of acceptable criteria. The oil used in the generator hydrogen seals is supplied from an auxiliary reservoir. Hydrogen cooled turbo generators are designed to provide a lowdrag atmosphere and cooling for singleshaft and combinedcycle applications in combination with steam turbines.
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