14-08-2012, 12:05 PM
INDIAN OIL CORPORATION LIMITED HALDIA OIL REFINERY
VOCATIONAL TRAINING REPORT.doc (Size: 4.94 MB / Downloads: 492)
INTRODUCTION
Haldia Refinery, the fourth in the chain of seven operating refineries of Indian
Oil, was commissioned in January 1975. It is situated 136 km downstream of
Kolkata in the district of East Midnapur, West Bengal, near the confluence of river
Hoogly and river Haldi. The refinery had an original crude oil processing capacity
of 2.5 MMTPA. Petroleum products from this Refinery are supplied mainly to
eastern India through two Product Pipelines as well as through Barges, Tank
Wagons and Tank Trucks. Products like MS, HSD and Bitumen are exported from
this refinery.
The strategic significance of this Refinery lies in its being the only coastal refinery of
the Corporation and the lone lube flagship, apart from being the sole producer of
Jute Batching Oil and Russian Turbine Fuel. Capacity of the Refinery was increased
to 2.75 MMTPA through de-bottlenecking in 1989-90. Refining capacity was further
increased to 3.75 MMTPA in 1997 with the installation/commissioning of second
Crude Distillation Unit of 1.0 MMTPA capacity. Diesel Hydro Desulphurisation
(DHDS) Unit was commissioned in 1999, for production of low Sulphur content
(0.25% wt) High Speed Diesel (HSD). With augmentation of this unit, refinery is
producing BS-II and Euro-III equivalent HSD (part quantity) at present.
Reside Fluidized Catalytic Cracking Unit (RFCCU) was commissioned in 2001 in
order to increase the distillate yield of the refinery as well as to meet the growing
demand of LPG, MS and HSD. Refinery also produces eco friendly Bitumen
emulsion and Microcrystalline Wax. In addition, a Catalytic Dewaxing Unit
(CIDWU) was installed and commissioned in 2003, for production of high quality
Lube Oil Base Stocks (LOBS), meeting the API Gr-II standard of LOBS. This is the
only refinery in the country to produce such high quality LOBS.
EFFICINECY:
Power is energy per time. The power output or capacity of an electric plant can be expressed in units of Megawatts electric. The electric efficiency of a conventional thermal power station, considered as salable energy (in MWs) produced at the plant busbars as a percent of the heating value of the fuel consumed. This efficiency is limited as all heat engines are governed by laws of thermodynamics. The rest of the energy must leave the plant in the form of heat. This waste heat can go through a condenser and disposed of with cooling water or in cooling towers.
Since efficiency of the plant is fundamentally limited by the ratio of the absolute temperatures of the steam at turbine input and output, efficiency improvements require use of higher temperature, and therefore pressure, steam.
STEAM TURBINE DRIVEN ELECTRIC GENERATOR:
The steam turbine driven generators have auxiliary systems enabling them to work satisfactorily and safely. The steam turbine generator being rotating equipment generally has a heavy, large diameter shaft. The shaft therefore requires not only supports but also has to be kept in position while running. To minimize the frictional resistance to the rotation, the shaft rotates are lined with a low friction material like Babbit Metal. Oil lubrication is provided to further reduce the friction between shaft and bearing surface and to limit the heat generated. n Haldia refinery’s thermal power station there are 4 generators. 3 of them have rating of 10.5 MW and the other one has a capacity of 16.5 MW. The static part of the generator is stator which is 3 phase double star winding from which is output 3 phase AC power is available at a rated voltage of 6.6KV. The rotating part of generator is rotor which has field winding excited by controlled DC power supplied from AVR (Automatic Voltage Regulator) through carbon brushes & slip rings mounted on the rotor shaft. The direction of rotation of generator rotor is anticlockwise when viewed from slip rings side. Both stator & rotor of generator is cooled by natural air cooling. The generators have the following specifications:
MAINTENANCE OF THE ELECTRICAL EQUIPMENTS OF A THERMAL POWER STATION:
MOTOR MAINTENANCE:
All the rotating machines are subjected to various forces like voltages, currents, centrifugal & axial forces, temperature, friction etc. during running. Even during standstill, these are subjected to ambient climatic conditions like temarature, humadity, presence of corrosive & oxidizing gases etc. Under the influence of this factors, any rotating machine is bound to deteriorate with time, increasing the probability of its failure during running or at the time of starting. This, in turn, may lead to loss of production and in extreme cases, to accidents and / or fire.
The whole philosophy of maintenance of motors stems from the need to eliminate the possibility of failure as above. The major maintenance activities to achieve this objective can be broadly classified into three categories:
1. Preventive maintenance: This comprises a set of maintenance activities carried out on the motors at fixed intervals of time, irrespective of the condition of the motor. The purpose is not to allow the motor condition to deteriorate below a safe level. This greatly reduces the possibility of failure. Further, as these are planned beforehand and carried out on stand-by motors, there is little possibility of any loss production. This is of three types:
1.“A” Schedule maintenance-once every six months
2. “B” Schedule maintenance-depending on the motor condition, but normally before one year.
3. “C” Schedule maintenance-depending on the motor condition based on the test results.
2. Predictive maintenance: As the condition of any motor deteriorates, it starts sending out signals to this effect. The signals may be as varied as the nature & extent of deterioration, and in most cases, start coming much before the deterioration can reach the failure stage. Predictive maintenance activities comprise of a timely detection & measurement of these signals & inductors, their interpretation, and planning & execution of corrective action accordingly. This even further reduces the possibility of failure & resulting loss of production.