Mechanical Engineering - Hydraulic Machines - Discussion

Discussion Forum : Hydraulic Machines - Section 3 (Q.No. 32)
32.
A turbine is required to develop 1500 kW at 300 r.p.m. under a head of 150 m. Which of the following turbine should be used ?
Pelton wheel with one nozzle
Pelton wheel with two or more nozzles
Kaplan turbine
Francis turbine
Answer: Option
Explanation:
No answer description is available. Let's discuss.
Discussion:
22 comments Page 1 of 3.

Deepak said:   9 years ago
The correct option is D. Francis turbine.

Because Francis turbine is a medium head and medium specific speed turbine. For Francis turbine head range is 60 - 250 m and specific speed vary from 60 - 300 rpm.

Kaplan turbine is used for head below 60 m and specific speed ranges as 300 - 1000 rpm.

Manu M.S said:   3 years ago
N*√T/ H^5/4.
300*√ 1500/150^5/4,
300*38.7/525,
11625/525.
22.14.

The specific speed of the Pelton turbine is 1 to 30.
Francis turbine = 60 to 300.
Kaplan turbine = 300 to 1000.
So, option A is correct.

Ganeshr said:   4 years ago
@Ajaypal

The range of specific speed is wrong.

Range for sp. Speed.
For pelton or impulse - 1-10.
Francis-10-100.
Kaplan- more than 100 rpm.

Correct ans is francis turbine 22.13 lies between 10-100.

Kolli Dayakar said:   5 years ago
Francis turbine is used when the available head of water is 25m to 250m.

Here, the head is 150m.

60 to 300 rpm for Francis turbine.

So, I think the answer will be Francis turbine (D).

Ajaypal said:   8 years ago
Specific Speed (Ns) is criterion for deciding the type of turbine to be used.

Ns = [N(Q)^0.5]/H^(5/4).
So, Ns = 22.13 RPM.
and it is in range of Pelton Turbine.

Subrata ghorai said:   3 years ago
Yes, the answer is correct, the specific speed is determines which turbine is we use 22.14 is less than 30 impulse turbine use.

Ashish said:   8 years ago
Calculating the specific speed, we can easily get value recommended for Peyton wheel with one jet.

Vinay said:   5 years ago
Given answer is correct. While calculating specific speed we always put power in kw.

Sandeep kumar gupta said:   9 years ago
May be the correct answer is D. Please clear my doubt with the correct explanation.

Radheshyam Sharma said:   10 years ago
Pelton or impulse turbine is used for high head and low discharge.


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