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Consider the following statements regarding turbines: I. the main function of a governor is to maintain a constant speed even as the load on the turbine fluctuates 2. In the cast of Pelton turbines, the governor closes or opens the wicket gates 3. In the case of Francis turbines, the governor opens or closes the needle valve 4. In the case of a Kaplan turbine, the governor swings the runner blades appropriately in addition to further Closing or further opening of wicket gates Which of the above statements are correct?

Consider the following statements regarding turbines: I. the main function of a governor is to maintain a constant speed even as the load on the turbine fluctuates 2. In the cast of Pelton turbines, the governor closes or opens the wicket gates 3. In the case of Francis turbines, the governor opens or closes the needle valve 4. In the case of a Kaplan turbine, the governor swings the runner blades appropriately in addition to further Closing or further opening of wicket gates Which of the above statements are correct? Correct Answer 1 and 4 only

Concept:

Governor of turbine:  A turbine governor is a component of the turbine control system that regulates rotational speed in response to fluctuating load conditions. The governor mechanism manipulates the position of either a steam inlet valve or nozzles or wicket gates which in turn regulates the steam flow to the turbine.

∴ Statement 1 is correct.

Governor in Pelton turbines:

In Pelton turbine, governor regulates of needle valve in the nozzle. In case of reduced load needle in the nozzle start moving forwards along with reduction in the area of openings and when loads increases, needle in the nozzle is pulled back to cause increase in the area of opening. The following diagram illustrates the governing mechanism in a Pelton turbine:

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∴ Statement 2 is incorrect.

Governor in Francis turbines:

In Francis turbine, governor regulates the guide vane by closing and opening the wicket gate, so the area of flow is decreased or increased respectively and constant speed can be maintained. The following diagram illustrates the governing mechanism in a Francis turbine:

[ alt="F2 A.M Madhu 12.05.20 D2" src="//storage.googleapis.com/tb-img/production/20/05/F2_A.M_Madhu_12.05.20_D2.png" style="width: 407px; height: 233px;">

∴ Statement 3 is incorrect.

Governor in Kaplan turbines:

In Kaplan turbine governor has double control guide vane which controls flow and inlet angle. In addition to that individual blades can also be rotated about their respective axis. So, to maintain constant speed governor swings the runner blades appropriately in addition to further regulating the wicket gates.

∴ Statement 4 is correct.

Related Questions

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