Bissoy.com
Doctors Medicines MCQs Q&A

When there is a sudden reduction in load on the turbine in a hydel plant, the governor closes the gates of the turbine to reduce the water flow. This causes pressure to increase abnormally in the penstock. How is this prevented?

When there is a sudden reduction in load on the turbine in a hydel plant, the governor closes the gates of the turbine to reduce the water flow. This causes pressure to increase abnormally in the penstock. How is this prevented? Correct Answer <span style=""> By using a surge tank</span>

Components of a Hydro-Power Plant:

[ alt="F1 Nakshatra Madhuri 11.02.2022 D1" src="//storage.googleapis.com/tb-img/production/22/02/F1_Nakshatra_Madhuri_11.02.2022_D1.png" style=" height: 176px; width: 350px;">

1.) Dam: A dam is a barrier that stores water and creates a water head. Dams are built of concrete or stone masonry, earth, or rock fill.

2.) Spillways: There are times when the river flow exceeds the storage capacity of the reservoir. Such a situation arises during heavy rainfall in the catchment area. In order to discharge the surplus water from the storage reservoir into the river on the downstream side of the dam, spillways are used.

3.) Penstock: Penstocks are open or closed conduits that carry water to the turbines. They are generally made of reinforced concrete or steel.

4.) Surge tank:

  • When the turbine is running at a steady load, there are no surges in the flow of water through the conduit.
  • When the load on the turbine decreases, the governor closes the gates of the turbine, reducing the water supply to the turbine.
  • The excess water at the lower end of the conduit rushes back to the surge tank and increases its water level.
  • Thus the conduit is prevented from bursting.
  • When the load on the turbine increases, additional water is drawn from the surge tank to meet the increased load requirement.
  • Hence, a surge tank overcomes the abnormal pressure in the conduit when the load on the turbine falls and acts as a reservoir during the increase of load on the turbine.

Related Questions

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?
In each question below is given a statement numbered I, II and III. An assumption is something supposed or taken for granted. You have to consider the following assumption and decide which of the assumption is implicit in the statement. Statement: The Amazon.com Inc. founder, Jeff Bezos’s net worth broke $150 billion in New York on Monday morning, according to the Bloomberg Billionaires Index. That’s about $55 billion more than Microsoft Corp. co-founder Bill Gates, the world’s second-richest person. Bezos, 54, has now topped Gates in inflation-adjusted terms. The $100 billion mark that Gates hit briefly in 1999 at the height of the dot-com boom would be worth about $149 billion in today’s dollars. Assumptions: I. Jeff Bezos is the richest person in modern history. II. That makes the Amazon founder richer than anyone else on earth since at least 2000 when Forbes published its inaugural wealth ranking. III. Gates would have had a net worth of more than $150 billion if he’d held onto assets that he’s given away, largely to the Bill & Melinda Gates Foundation.
Which of the following statement(s) is/are incorrect? (i) A turbine is called an impulse turbine if at the inlet of the turbine total energy is only kinetic energy (ii) A turbine is called a reaction turbine if at the inlet of the turbine the total energy is kinetic energy and pressure energy (iii) The inward flow reaction turbine having radial discharge at the outlet is known as Kaplan turbine
Consider the following statements in connection with hydraulic turbines: 1. The Kaplan turbine is a radial flow turbine in which the guide vane angles as well as the runner vane angles are adjustable. 2. Francis and Kaplan turbines are provided with draft tubes which carry water from exit of runner to tail water to increase the gross head across the turbine. 3. The parts of turbines susceptible to cavitation are the guide vanes and runner vanes – drastically reducing the turbine efficiency. 4. The specific speed of a 4-jet Pelton turbine will be 28 if the specific speed of a single-jet Pelton turbine is 14. Which of the above statements are correct?
Below some statements are given. You have to take the given statements to be true even if they appear to be at variance with commonly known facts, and then decide which of conclusions logically follows from the given statements. For each question, mark out an appropriate answer choice that you think is correct. Statements: All gates are libraries. Some gates are poles. No pole is room. Some rooms are halls. Conclusions: I) Some poles are library. II) Some gates are room. III) Some libraries are gates.
Calculate the minimum number of AND gates, OR gates and NOT gates required to realize Exclusive-OR operation if only using AND, OR and NOT gates are allowed.
Calculate the hoop stress at the bottom of penstock, if a steel penstock of 1 m and 10 mm thick is subjected to 100m head of water. Take w = 9.81 kN/m3.
Consider the following statement: 1. Initial load tests and routine load tests are carried out on test piles and working Piles, respectively. 2. In a pile load test, the allowable load can be taken equal to half the ultimate load at which the total settlement amounts to one-tenth of the pile diameter. 3. In a pile load test, the allowable load can be taken equal to two-thirds of the total toad which causes a plastic settlement of 6 mm. Which of the above statements are correct?
In the following question, the 1st and the last part of the sentence/ passage are numbered 1 and 6. The rest of the sentence/passage is split into four parts and named P, Q, R and S. These four parts are not given in their proper order. Read the sentence/passage and find out which of the four combinations is correct.  1. Blood pumps through the circulatory system of the human body. P. Over time, the increased pressure on the arteries can cause a wide range of problems. Q. Hypertension occurs when the force exerted against artery walls is abnormally high. R. Just as too much water pressure can damage pipes and faucets, high blood pressure can spell trouble. S. When blood is under pressure, it is like the water in the pipes of a house. 6. Small bulges, called aneurysms, may form in blood vessels
Consider the following statements: 1. In an Impulse turbine, the pressure of the flowing water remains un- changed and is equal to atmospheric Pressure. 2. In Impulse turbines, the water impinges on the buckets with ‘Pressure energy’. 3. In a Reaction turbine, the pressure of the flowing water remains un- changed and is equal to atmospheric pressure. Which of the above statements is/are correct?