Homework Help is Here – Start Your Trial Now!
Engineering
Mechanical Engineering
Problem 4. Water at atmospheric pressure is de-aerated and preheated in a tank at an elevation of Azs = 2.0 m above a feed-water pump that delivers it to a boiler to produce steam as shown. The pump suction inlet and pump discharge inside diameters are D = 10 cm and D₁ = 7.5 cm, respectively. To determine the net positive suction head required, NPSHR, an additional valve is placed upstream of the pump suction inlet and adjusted until cavitation just begins to occur. During testing using water at STP when the pump is operated at a volumetric flowrate of Q = 0.025 m³/s, against a head of H₂ = 25 m, cavitation is observed to begin when the pressure gage at the suction inlet reads Ps,gage = 1.0 kPa. (a) Calculate the NPSHR for these test conditions. (b) Calculate the gage pressure reading at the pump discharge. (c) Assuming negligible major and minor losses before the suction inlet, calculate the net positive suction head available, NPSHA , when the pump is operated in the field at the same Q and Hp, but for a water temperature of T₁ = 90° C. (d) Briefly discuss if the pump will cavitate for these field conditions, how your answer changes with Tƒ, and three ways to reduce the likelihood for cavitation to occur. ▼ ATMOSPHERIC DEAERATOR STEAM Azs ☑☑N b PUMP GLOBE GATE CHECK VALVE VALVE VALVE BOILER

Problem 4. Water at atmospheric pressure is de-aerated and preheated in a tank at an elevation of Azs = 2.0 m above a feed-water pump that delivers it to a boiler to produce steam as shown. The pump suction inlet and pump discharge inside diameters are D = 10 cm and D₁ = 7.5 cm, respectively. To determine the net positive suction head required, NPSHR, an additional valve is placed upstream of the pump suction inlet and adjusted until cavitation just begins to occur. During testing using water at STP when the pump is operated at a volumetric flowrate of Q = 0.025 m³/s, against a head of H₂ = 25 m, cavitation is observed to begin when the pressure gage at the suction inlet reads Ps,gage = 1.0 kPa. (a) Calculate the NPSHR for these test conditions. (b) Calculate the gage pressure reading at the pump discharge. (c) Assuming negligible major and minor losses before the suction inlet, calculate the net positive suction head available, NPSHA , when the pump is operated in the field at the same Q and Hp, but for a water temperature of T₁ = 90° C. (d) Briefly discuss if the pump will cavitate for these field conditions, how your answer changes with Tƒ, and three ways to reduce the likelihood for cavitation to occur. ▼ ATMOSPHERIC DEAERATOR STEAM Azs ☑☑N b PUMP GLOBE GATE CHECK VALVE VALVE VALVE BOILER

Refrigeration and Air Conditioning Technology (MindTap Course List)
Refrigeration and Air Conditioning Technology (MindTap Course List)
8th Edition
ISBN:9781305578296
Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson
Publisher:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson
Chapter40: Typical Operating Conditions
Section: Chapter Questions
Problem 10RQ: The seasonal energy efficiency ratio (SEER) includes the energy used in the _____and _____cycles.
See similar textbooks
icon
Related questions
Question
Problem 4. Water at atmospheric pressure is de-aerated and preheated in a tank at an elevation of Azs = 2.0 m above a feed-water pump that delivers it to a boiler to produce steam as shown. The pump suction inlet and pump discharge inside diameters are D = 10 cm and D₁ = 7.5 cm, respectively. To determine the net positive suction head required, NPSHR, an additional valve is placed upstream of the pump suction inlet and adjusted until cavitation just begins to occur. During testing using water at STP when the pump is operated at a volumetric flowrate of Q = 0.025 m³/s, against a head of H₂ = 25 m, cavitation is observed to begin when the pressure gage at the suction inlet reads Ps,gage = 1.0 kPa. (a) Calculate the NPSHR for these test conditions. (b) Calculate the gage pressure reading at the pump discharge. (c) Assuming negligible major and minor losses before the suction inlet, calculate the net positive suction head available, NPSHA , when the pump is operated in the field at the same Q and Hp, but for a water temperature of T₁ = 90° C. (d) Briefly discuss if the pump will cavitate for these field conditions, how your answer changes with Tƒ, and three ways to reduce the likelihood for cavitation to occur. ▼ ATMOSPHERIC DEAERATOR STEAM Azs ☑☑N b PUMP GLOBE GATE CHECK VALVE VALVE VALVE BOILER
Transcribed Image Text:Problem 4. Water at atmospheric pressure is de-aerated and preheated in a tank at an elevation of Azs = 2.0 m above a feed-water pump that delivers it to a boiler to produce steam as shown. The pump suction inlet and pump discharge inside diameters are D = 10 cm and D₁ = 7.5 cm, respectively. To determine the net positive suction head required, NPSHR, an additional valve is placed upstream of the pump suction inlet and adjusted until cavitation just begins to occur. During testing using water at STP when the pump is operated at a volumetric flowrate of Q = 0.025 m³/s, against a head of H₂ = 25 m, cavitation is observed to begin when the pressure gage at the suction inlet reads Ps,gage = 1.0 kPa. (a) Calculate the NPSHR for these test conditions. (b) Calculate the gage pressure reading at the pump discharge. (c) Assuming negligible major and minor losses before the suction inlet, calculate the net positive suction head available, NPSHA , when the pump is operated in the field at the same Q and Hp, but for a water temperature of T₁ = 90° C. (d) Briefly discuss if the pump will cavitate for these field conditions, how your answer changes with Tƒ, and three ways to reduce the likelihood for cavitation to occur. ▼ ATMOSPHERIC DEAERATOR STEAM Azs ☑☑N b PUMP GLOBE GATE CHECK VALVE VALVE VALVE BOILER
Expert Solution
steps

Step by step

Solved in 2 steps with 1 images

SEE SOLUTIONCheck out a sample Q&A here
Blurred answer
Similar questions
  • SEE MORE QUESTIONS
Recommended textbooks for you
Refrigeration and Air Conditioning Technology (Mi…
Refrigeration and Air Conditioning Technology (Mi…
Mechanical Engineering
ISBN:
9781305578296
Author:
John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson
Publisher:
Cengage Learning
SEE MORE TEXTBOOKS