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Why pumps are generally less efficient than turbines?
A centrifugal pump is required to deliver 50 litres of water per second to a height of 30 m through a 100 m long pipe of 15 cm diameter. The inlet losses in the suction pipe are estimated to be 0.35 m. Assuming an overall efficiency of 70 percent and taking Darcy’s friction coefficient 0.015 for the pipeline, determine the power required to drive the pump, in kW.
Correct answer is 'Range: 30 to 35'. Can you explain this answer?
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Why pumps are generally less efficient than turbines?A centrifugal pu...
Flow is of accelerating type in turbines and of decelerating type in pumps. As such, the tendency for boundary layer separation and eddy formation increases the hydraulic loss in pumps. Besides, turbines are usually of larger size than pumps and that result in reduced friction loss.
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= 32953 W ≈ 32.95 kW
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Why pumps are generally less efficient than turbines?A centrifugal pu...
Why pumps are generally less efficient than turbines?
- Turbines convert fluid pressure into rotational energy while pumps do the opposite, converting rotational energy into fluid pressure.
- Turbines generally have a simpler design and fewer losses due to friction, resulting in higher efficiency.
Calculation of power required to drive the pump:
- Flow rate = 50 litres/second
- Total head = 30 m
- Inlet losses = 0.35 m
- Pipe length = 100 m
- Pipe diameter = 15 cm = 0.15 m
- Friction coefficient = 0.015
- Overall efficiency = 70%
Using the Bernoulli equation, we can calculate the head loss due to friction:
- Head loss = (friction coefficient x pipe length x velocity^2) / (2 x pipe diameter)
- Velocity = (flow rate) / (cross-sectional area of pipe) = (50 / (3.14 x 0.075^2)) = 188.5 m/s
- Head loss = (0.015 x 100 x 188.5^2) / (2 x 0.15) = 352.5 m
Total head = 30 + 0.35 + 352.5 = 382.85 m
The power required to drive the pump can be calculated using the following formula:
- Power = (flow rate x total head x density of water x gravity) / (overall efficiency)
- Density of water = 1000 kg/m^3
- Gravity = 9.81 m/s^2
- Power = (50 x 382.85 x 1000 x 9.81) / (0.7 x 1000) = 679.8 kW
The answer falls within the range of 30 to 35 kW, indicating that there may be some rounding errors in the calculations or variations in the assumed values.
- Turbines convert fluid pressure into rotational energy while pumps do the opposite, converting rotational energy into fluid pressure.
- Turbines generally have a simpler design and fewer losses due to friction, resulting in higher efficiency.
Calculation of power required to drive the pump:
- Flow rate = 50 litres/second
- Total head = 30 m
- Inlet losses = 0.35 m
- Pipe length = 100 m
- Pipe diameter = 15 cm = 0.15 m
- Friction coefficient = 0.015
- Overall efficiency = 70%
Using the Bernoulli equation, we can calculate the head loss due to friction:
- Head loss = (friction coefficient x pipe length x velocity^2) / (2 x pipe diameter)
- Velocity = (flow rate) / (cross-sectional area of pipe) = (50 / (3.14 x 0.075^2)) = 188.5 m/s
- Head loss = (0.015 x 100 x 188.5^2) / (2 x 0.15) = 352.5 m
Total head = 30 + 0.35 + 352.5 = 382.85 m
The power required to drive the pump can be calculated using the following formula:
- Power = (flow rate x total head x density of water x gravity) / (overall efficiency)
- Density of water = 1000 kg/m^3
- Gravity = 9.81 m/s^2
- Power = (50 x 382.85 x 1000 x 9.81) / (0.7 x 1000) = 679.8 kW
The answer falls within the range of 30 to 35 kW, indicating that there may be some rounding errors in the calculations or variations in the assumed values.
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Why pumps are generally less efficient than turbines?A centrifugal pump is required to deliver 50 litres of water per second to a height of 30 m through a 100 m long pipe of 15 cm diameter. The inlet losses in the suction pipe are estimated to be 0.35 m. Assuming an overall efficiency of 70 percent and taking Darcy’s friction coefficient 0.015 for the pipeline, determine the power required to drive the pump, in kW.Correct answer is 'Range: 30 to 35'. Can you explain this answer?
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Why pumps are generally less efficient than turbines?A centrifugal pump is required to deliver 50 litres of water per second to a height of 30 m through a 100 m long pipe of 15 cm diameter. The inlet losses in the suction pipe are estimated to be 0.35 m. Assuming an overall efficiency of 70 percent and taking Darcy’s friction coefficient 0.015 for the pipeline, determine the power required to drive the pump, in kW.Correct answer is 'Range: 30 to 35'. Can you explain this answer? for Civil Engineering (CE) 2024 is part of Civil Engineering (CE) preparation. The Question and answers have been prepared according to the Civil Engineering (CE) exam syllabus. Information about Why pumps are generally less efficient than turbines?A centrifugal pump is required to deliver 50 litres of water per second to a height of 30 m through a 100 m long pipe of 15 cm diameter. The inlet losses in the suction pipe are estimated to be 0.35 m. Assuming an overall efficiency of 70 percent and taking Darcy’s friction coefficient 0.015 for the pipeline, determine the power required to drive the pump, in kW.Correct answer is 'Range: 30 to 35'. Can you explain this answer? covers all topics & solutions for Civil Engineering (CE) 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Why pumps are generally less efficient than turbines?A centrifugal pump is required to deliver 50 litres of water per second to a height of 30 m through a 100 m long pipe of 15 cm diameter. The inlet losses in the suction pipe are estimated to be 0.35 m. Assuming an overall efficiency of 70 percent and taking Darcy’s friction coefficient 0.015 for the pipeline, determine the power required to drive the pump, in kW.Correct answer is 'Range: 30 to 35'. Can you explain this answer?.
Why pumps are generally less efficient than turbines?A centrifugal pump is required to deliver 50 litres of water per second to a height of 30 m through a 100 m long pipe of 15 cm diameter. The inlet losses in the suction pipe are estimated to be 0.35 m. Assuming an overall efficiency of 70 percent and taking Darcy’s friction coefficient 0.015 for the pipeline, determine the power required to drive the pump, in kW.Correct answer is 'Range: 30 to 35'. Can you explain this answer? for Civil Engineering (CE) 2024 is part of Civil Engineering (CE) preparation. The Question and answers have been prepared according to the Civil Engineering (CE) exam syllabus. Information about Why pumps are generally less efficient than turbines?A centrifugal pump is required to deliver 50 litres of water per second to a height of 30 m through a 100 m long pipe of 15 cm diameter. The inlet losses in the suction pipe are estimated to be 0.35 m. Assuming an overall efficiency of 70 percent and taking Darcy’s friction coefficient 0.015 for the pipeline, determine the power required to drive the pump, in kW.Correct answer is 'Range: 30 to 35'. Can you explain this answer? covers all topics & solutions for Civil Engineering (CE) 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Why pumps are generally less efficient than turbines?A centrifugal pump is required to deliver 50 litres of water per second to a height of 30 m through a 100 m long pipe of 15 cm diameter. The inlet losses in the suction pipe are estimated to be 0.35 m. Assuming an overall efficiency of 70 percent and taking Darcy’s friction coefficient 0.015 for the pipeline, determine the power required to drive the pump, in kW.Correct answer is 'Range: 30 to 35'. Can you explain this answer?.
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Why pumps are generally less efficient than turbines?A centrifugal pump is required to deliver 50 litres of water per second to a height of 30 m through a 100 m long pipe of 15 cm diameter. The inlet losses in the suction pipe are estimated to be 0.35 m. Assuming an overall efficiency of 70 percent and taking Darcy’s friction coefficient 0.015 for the pipeline, determine the power required to drive the pump, in kW.Correct answer is 'Range: 30 to 35'. Can you explain this answer?, a detailed solution for Why pumps are generally less efficient than turbines?A centrifugal pump is required to deliver 50 litres of water per second to a height of 30 m through a 100 m long pipe of 15 cm diameter. The inlet losses in the suction pipe are estimated to be 0.35 m. Assuming an overall efficiency of 70 percent and taking Darcy’s friction coefficient 0.015 for the pipeline, determine the power required to drive the pump, in kW.Correct answer is 'Range: 30 to 35'. Can you explain this answer? has been provided alongside types of Why pumps are generally less efficient than turbines?A centrifugal pump is required to deliver 50 litres of water per second to a height of 30 m through a 100 m long pipe of 15 cm diameter. The inlet losses in the suction pipe are estimated to be 0.35 m. Assuming an overall efficiency of 70 percent and taking Darcy’s friction coefficient 0.015 for the pipeline, determine the power required to drive the pump, in kW.Correct answer is 'Range: 30 to 35'. Can you explain this answer? theory, EduRev gives you an
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