1. General Description.
The
turbines for power plant shall be selected might be of vertical Francis
type or other type according to the site condition, and might consists
of some components such as spiral casing, draft tube, turbine runner,
shaft, guide vane, control and other auxillary equipments.
The space prepared of this power plant shall be arranged for proper operation. The operation bay and erection bay will be prepared on floor EL x0,00 m. The draft tube gates is also to be operated and dogged on this floor elevation. On this elevation but in the other side of the power house, a room is also to be prepared for the use of machine shop.
Generator is installed in the generator chamber located on floor El.x5,00 m. For the underground type of power house from generator room a tunnel cable is run to the outer side of the power house with the length of about x00 meter.
The turbine pipe distributor will be connected to the inlet valve and spiral casing at the setting elevation El xx,xx meter.
At the elevation below the outlet of spiral casing the draft tube cone and the draft tube will be installed. For maintenance purpose the spiral casing is provided with a man hole positioned at the most down stream side of spiral casing.
The turbine and the generator usually direct coupled by means of coupling so the rotation speed of generator will be same with the turbine rotation speed.
The space prepared of this power plant shall be arranged for proper operation. The operation bay and erection bay will be prepared on floor EL x0,00 m. The draft tube gates is also to be operated and dogged on this floor elevation. On this elevation but in the other side of the power house, a room is also to be prepared for the use of machine shop.
Generator is installed in the generator chamber located on floor El.x5,00 m. For the underground type of power house from generator room a tunnel cable is run to the outer side of the power house with the length of about x00 meter.
The turbine pipe distributor will be connected to the inlet valve and spiral casing at the setting elevation El xx,xx meter.
At the elevation below the outlet of spiral casing the draft tube cone and the draft tube will be installed. For maintenance purpose the spiral casing is provided with a man hole positioned at the most down stream side of spiral casing.
The turbine and the generator usually direct coupled by means of coupling so the rotation speed of generator will be same with the turbine rotation speed.
2. Technical Data and Characteristics
High water level : xxx.x meterNormal water level : xxx.x meter
Low water level : xxx.x meter
Tail race water level : xx.xx meter
Tail race 1 operation : xx.xxmeter
Type : Francis – vertical shaft
Number : x units
Design head : xxx.xx meter
Discharge : x @ xx.x cms
Output : x @ xxx.x mW
Rotation speed : xxx rpm
Pipe center line : xx.xx m
3. Selection of Hydraulic turbine type
There
is a diagram called ‘Hydraulic Turbine type Selection Diagram’ in the
proposal of project. Taking the maximum discharge and optimum head etc.
Are most need to consider. The adaptation limit of each hydraulic
turbine type is decided on the basic experience, calculation and
maintain ability etc.
4.Turbine unit capacity
The
studies of Batang Toru hydraulic generation project should be checked
to assure that capacity limitations, due to generator size and variation
of turbine capacity with head, are allowed for the kilowatt (kW).
(1) rated discharge : Qd = xx.x cms
(2) Design head : hd= xxx m
(3) Turbine Eff : e=94% (estimated)
Formula : Pd=9,8 x Qd x hd x e =xxx.xx kW, say xxx.xx kW (xxx.x mW).
(1) rated discharge : Qd = xx.x cms
(2) Design head : hd= xxx m
(3) Turbine Eff : e=94% (estimated)
Formula : Pd=9,8 x Qd x hd x e =xxx.xx kW, say xxx.xx kW (xxx.x mW).
5. Number of units
A
new plant In this project, designed power plant can adjust the load
distribution and avoid low efficiency operation of any single plant. The
number of units can best be determined by equipment weight, maximum
overall size limitations and criteria. In consideration of the plant
common used equipment such as cranes, air compressors, oil handling
equipment etc. are smaller and can be used more efficiently.
In this project, two-units of turbine-generator is sufficiently adaptable to the usual load and flow variations, and the cost of project is very close to a minimum.
In this project, two-units of turbine-generator is sufficiently adaptable to the usual load and flow variations, and the cost of project is very close to a minimum.
6. Rated speed of revolution
Rated
speed of revolution and weight of the devices for hydraulic turbine
have a very close relation. When the head and output are given,
selection the high-specific speed of the turbine can be made.
High-specific speed means cheaper facilities because of the reduction in
weight and size. It even realizes the reduction in size and weight of
the identical capacity of hydraulic and generator. It’s not easy to
change the specific speed of Francis turbine. A smaller size unit and
lower cost of unit were the cause of high speed of revolution. If
turbine speed too high, the cavitation and vibration problem will
happen, moreover it were decreasing average efficiency of turbine. Then,
Draft head is tending toward lower or become negative values, also the
central line of turbine will have to be placed lower, the civil
engineering excavation of plant were deeper and increase investment
simultaneously.
Therefore, the highest specific speed is limited to rated head and output turbine. It means low specific speeds are associated with high heads and high specific speeds are associated with low heads. Selection of a high specific speed for a given head will result in a smaller turbine and generator. The application limit of specific speed (ns) against the head (h) is almost decided empirically, so the limit of specific speed for each hydraulic turbine was calculated. Therefore, to determine the rated speed, the specific speed limit of hydraulic turbine needs to be calculated.
Therefore, the highest specific speed is limited to rated head and output turbine. It means low specific speeds are associated with high heads and high specific speeds are associated with low heads. Selection of a high specific speed for a given head will result in a smaller turbine and generator. The application limit of specific speed (ns) against the head (h) is almost decided empirically, so the limit of specific speed for each hydraulic turbine was calculated. Therefore, to determine the rated speed, the specific speed limit of hydraulic turbine needs to be calculated.
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