Reference no: EM132490855
Project. Construction of Pump Performance Curves at Different Operating Conditions
A centrifugal pump has an impeller of diameter D =12.95 in. When pumping 59°F water at N = 1160 rpm, the measured flow rate Q and pressure rise 4 are given by the manufacturer as follows:
Q, gal/min
|
200
|
300
|
400
|
500
|
600
|
700
|
Δp, lb/in2
|
36
|
35
|
34
|
32
|
29
|
23
|
(i) Assuming that Δp = f(p, Q, D, Ω), use the pi theorem to rewrite this function in terms of dimensionless parameters and then plot the given data in dimensionless form.
(ii) Using the concept of similarity, calculate and plot Δp - Q characteristic curves for pump impeller diameters D = 11, 9, and 10.5 in, musing at the same rotational speed N = 1160 rpm.
(iii) Repeat part (b) but in this case calculate and plot Δp- Q characteristic curves for the pump impeller of diameter D= 12.95 in but run at different rotational speeds N = 1000, 850, and 700 rpm
(iv) lt is desired to use the same original pump (D = 12.95 in), to pump 59°F gasoline instead of water. Calculate and plot Δp - Q characteristic curves at N = 1000, 800 and 700 rpm.
(v) Compare the performance of the pump when used to pump different fluids. Replot the plots in C and that in (d) on one new plot.
(vi) The following tables represent the system curves the above pump to serve. The first table is the system curve in case of water flow and the second table is the system curve for the case of gasoline flow. Superimpose the plot of the system curves on pump curves' plots and determine the operating conditions ΔP & Q) for each of the above cases. The operating point is the point of intersection between the pump curve and the system curve.
System (case of Water)
Q,gpm
|
200
|
300
|
400
|
5130
|
600
|
700
|
Δp, lbf/in2
|
8.2
|
12.2
|
17.8
|
25
|
33.8
|
44.2
|
System (case of Gasoline)
|
|
|
|
|
|
Q,gpm
|
200
|
300
|
400
|
500
|
600
|
700
|
Δp, Ibf/in2
|
6.0
|
8.5
|
12.0
|
16.5
|
22.0
|
28.5
|