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<br />Facility Audit Report 10 <br />San Leandro WWTF <br />constant up to 3000 SCFM, then climbs in proportion to process air demand at higher airflows. <br />There are two validation points shown for the energy baseline. The Factory Curves point is the <br />intersection of system pressure and the Lamson factory flow vs. pressure curve, combined with <br />the corresponding point on the factory power vs. flow curve. This indicates the baseline flow <br />and power measurements are in agreement with the stated energy efficiency of the Lamson <br />blowers. Also, a March 3, 2011 spot observation of process airflow and power is in agreement <br />with the 2010 baseline relationship. From these observations, we have confidence the power <br />and airflow measurements are reasonably accurate. <br />Figure 3.2.1.1.1 – 2010 Baseline Energy Performance and Process Airflow Demand <br /> <br /> <br />Figure 3.2.1.1.2 shows the relationship between system pressure, measured at the blower <br />manifold, and process airflow bins, as determined during the March 2011 three week study. <br />The airflow during this period was limited to the lower flow range. A linear regression fit of the <br />data resulted in the correlation shown on the figure. This correlation was extrapolated to higher <br />airflows as needed to estimate the system pressure vs. airflow requirements for the retrofit <br />options that were evaluated. The March 3, 2011 spot measurement indicates ~0.2 psig lower <br />actual system pressure than predicted by the extrapolated correlation. <br />The March 3rd spot measurement also revealed the flow recorded by the SCADA system was <br />considerably less than expected from the factory curves, if the blower were only moving air from <br />atmospheric pressure to system pressure. The blower suction valve was partially closed during <br />the spot measurement, increasing the pressure drop the blower was acting upon, and reducing <br />flow accordingly. Some additional pressure drop, however, will be the result of friction on the <br />discharge side of the blower prior to the pressure measurement at expansion joints and elbows. <br />From the factory curve, the blower pressure differential appears ~2 psi greater than the system <br />pressure spot measurement. For the purpose of estimating the retrofit process air pressure <br />0% <br />10% <br />20% <br />30% <br />40% <br />50% <br />0 <br />50 <br />100 <br />150 <br />200 <br />250 <br />010002000300040005000600070008000 <br />Fl <br />o <br />w <br /> <br />F <br />r <br />e <br />q <br />u <br />e <br />n <br />c <br />y <br />, <br /> <br />% <br />Po <br />w <br />e <br />r <br />, <br /> <br />K <br />W <br />Process Airflow, SCFM <br />2010 Baseline KW <br />Factory Curves <br />3/3/11 Spot Measurement <br />2010 Process Airflow <br />Frequency, %