Purpose: To determine the total energy loss in a piping system, calculate the required power that a pump must provide, initial and annual pump operations costs and improve the design of the pumping system.
Problem: A small residential community in Delaware County, NY has a water supply system as shown in Figure 1. The water is assumed to be 60oF and pumped from a larger reservoir at a lower elevation to the community’s reservoir. The design flow is to be 360,000 gal/day, with the pump operating 6 hours per day and 300 days a year. The pipe line is a standard 8-inch Schedule 40 steel pipe. Assume the entrance from the reservoir to the piping system is an inward projecting pipe and the elbows are 90o standard. There are two (2) gate valves (fully open) and one (1) check valve (ball type). Assume a pump of 76% efficiency will be used. Chapter 11 (Mott) of your textbook offers excellent examples of pipe systems.
You are the local engineer charged with reviewing the design of the piping system and determining the amount of power required to pump the water to the residential community’s reservoir and to report the initial and annual operation cost of the pump. You are to select from one of the pumps below:
When determining the power that the pump must deliver, be sure to take the following energy losses into account:
1. Frictional losses in the total pipeline
2. Entrance local losses
3. Local losses due to valves and elbows
4. The energy head needed to elevate the flow to reach the discharge point
Submission: Each student is required to submit the following:
Cover Letter is to be typed on 8.5” x 11” plain white paper. The letter is to be addressed to the Delaware Senior Communities, 186 Jay Street, Brook Lynn, NY 10211. The response is to include the following information:
1. The required power (in horsepower) that the pump will need to provide.
2. The initial cost of the pump.
3. The annual operations cost of the pump assuming it costs $0.20/kw-hour (per kilowatt hour).
Calculations are to be done by hand on 8.5” x 11” engineering paper. Show all work to obtain full credit. Be sure to clearly identify the frictional head loss for the total length of pipe, entrance, exit, valves and elbows. Clearly show calculations for determining pump power (in horsepower and conversion to kilowatts), and operations costs analysis.
Due: Beginning of Lecture 20