Chapter 4 Hydraulic Turbine / Generator

Article 91. Oil Treatment (Deleted)

(Article 91 is deleted and moved to Article 382-a1 of Chapter 15 “Energy Oil” in Part 6.)

Article 92. Efficient operation

1.The turbine or pump-turbine must be, basically, operated within high-efficiency area in the efficiency curve (hill curve) according to the requirement of relevant situation for power system and hydraulic condition.

2.The power plant is generally operated by some control devices after parallel-in the power system, such as Automatic frequency control (AFC), Joint control (Automatic Load Regulator (ALR) and/or Automatic Reactive Power Regulator (AQR)), Governor free operation, Load limiting control. When they are applied, it is necessary to set them at a high effective position to get optimum power taking account of the relevant situation for power system, hydraulic condition, etc,

3.In case of pumping operation of the pumped storage power plant, a control device is applied confirming the difference between water levels of upper and lower pounds, in order to curry out an optimum pumping operation.

Article 93. Changeable operation mode

1.In case of equipping a remote control and automatic controlling system in the power plant, it is necessary to conduct the tests to confirm the changeable operation mode shown in Table 93-1, -2 and Figure 93-1 as well as a manual control to be controlled by the master switch.

2.The requirements of changeable operation mode for hydraulic power plant must be specified by the Technical Specifications of each power plant as follows, shown in Table 93-1, -2 and Figure 93-1 in general;

Table 93-1 Changeable Operation Mode

Note: 1. Power plant 2) could be changeable both modes between (G) and (SG) vice versa. 2. Power plant 3) could be changeable as following Table 93-1;

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Operating indicator or

Alarm Systems record for protection

(Main and auxiliary equipment troubles)

devices

Figure 95-1 Sequence Diagram of Protection System

Article 96. Operation approval

1.The Owner must prepare the checking sheets with inspection/test plan for all equipment/devices before starting working at the site. The checking sheets of the inspection/test must be shown on the previous data with manufacturers' data for each equipment/device.

2.The results of inspection/test must be confirmed by Owner for all equipment/devices carefully, and after that, the Owner must approve to start-up the generator in a cautious manner for every location.

Article 97. Vibration

<Refer to Article 98-a1 of Guideline for Technical Regulation Vol.5.>

Article 98. Runner inspection

1.In case where works need being implemented in runner pit, it is imperative to discharge all water from penstock and/or runner pit through the drainage pipe.

(1)If an inlet valve to be installed between the penstock and spiral casing of turbine, all water in the penstock and runner pit is not necessary to discharge from penstock in general, i.e. the water in the runner pit must be drained after closing and mechanical & electrical locking the inlet valve and a draft tube gate completely.

(2)If an inlet valve to be not installed between the penstock and spiral casing of turbine, all water in the penstock and runner pit is necessary to discharge from penstock and runner pit, i.e. all water in the penstock and runner pit must be drained after closing and mechanical & electrical locking the intake gate and a draft tube gate completely.

2.The runner inspection must be carried out to check cavitation corrosion, erosion, crack, etc., together with inspection for the spiral casing, wicket gate with its sealing gaps, draft tube, painting condition of inside, etc., in accordance with an operation & maintenance manuals of each power plant.

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3.The repairing cavitation corrosion, erosion, crack, etc., must be curried out by the suitable process, <e.g.> a welding process. However, a suitable repairing period must be decided by the result of the inspection.

Pit liner Turbine Shaft

Regulating Ring

Wicket Gate

Spiral Casing

Upper Draft

Figure 98-1 Cross-section of Francis Turbine (An example of Turbine Pit of Hydraulic Power Plant)

Article 99. Hydraulic pressure inside penstock

1.The designed value of pressure rise ratio (∆P) of the penstock for the load rejection must be specified in the Technical Specification according to the type of civil design of power plant, as follows;

(1)In case of long length penstock or high water head for turbine, a pressure rise ratio is small. <e.g.> ∆P ≤ 40%, (refer to speed rise ratio of turbine : ∆N ≥ 40%)

(2)In case of short length penstock or low water head for turbine, a pressure rise ratio is high. <e.g.> ∆P ≥ 60% (refer to speed rise ratio of turbine : ∆N ≤ 15 %)

<Refer to Item 9, in Article 92 of Guideline for Technical Regulation Vol.5.>

2.Once reducing valve is available, its automatic operation must be in line with the Technical Specifications of equipment and not cause head loss.

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Referenced Standards and Regulations

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