• The technique used to determine how independent variable values will impact a particular dependent variable under a given set of assumptions is defined as sensitive analysis . It’s usage will depend on one or more input variables within the specific boundaries, such as the effect that changes in interest rates will have on a bond’s price.
• It is also known as the what – if analysis. Sensitivity analysis can be used for any activity or system. • It helps in analyzing how sensitive the output is, by the changes in one input while keeping the other inputs constant.
• Let the base case inputs of the equation be: • Z a = 20m Z b = 5m • P a = 24 000 P b = 23 000 • U a = 50 U b = 45 • Then; • Assume uniform velocity distribution in the pipeline or waterway and; • p = 1000 g = 9.81
• Therefore the equation yields to
Objective: In broad terms, the objective of the performance testing of SHP stations can be stated as under: (i) To verify that all parts, systems and auxiliaries in the power station are performing their assigned functions correctly. (ii) To verify that the generating units in the plant are operating at or above the prescribed efficiency value. The objective of (i) is to check the qualitative working of the power plant, while that of (ii) is to find out whether the generating units meet the mandated efficiency requirements.
Performance Test There are 2 main types of test done on a Mini Hydro Power plant : 1.) Maximum Power Output Test 2.) Unit Efficiency Test
General Methods of Power Measuremet The power output from the turbine shaft may be measured by one of the following primary methods: 1. Mechanical Brake 2. Water Brake 3. Electrical Brake 4. Torsion Dynamometer All the above methods involve the simultaneous measurement of net Torque(in mkg) and Shaft Speed(in rev/min) from which the net power output in KW from the turbine shaft may be computed from the following expression: P = 2πNT/60
In methods 1), 2) and 3), the torque on the brake is determine by the effective force applied to the brake arm and the radius at which it is applied. In method 4), the torque must be computed by means of a previous calibration. TORQUE MEASUREMENT Water Break -the water or Froude Brake consists of a bladed disk fixed to the shaft, and rotating inside a casing filled with water or oil and able to pivot about the shaft axis. The torque is varied by altering the amount of liquid in the casing . It thus absorbs power hydro dynamically, the torque reaction being measured on the pivoting casing.
UNIT EFFECIENCY TEST • Unit Efficiency Test The test aims at determining the actual efficiency of the generating unit(s) under specified conditions. This is the most difficult and time- consuming test in the whole exercise of performance testing of a power station. The efficiency of a turbine-generator unit is given by the ratio of the electrical power output of the generator to the hydroelectric power input to the turbine. The latter is equal to the product of the net water head availed by the turbine, the discharge rate
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- Summer '16
- Hydro Power Plant