Capital investment planning is not the only reason for power plants to have a clear understanding of their cooling water flows and pumping system performance. Today, environmental factors such as fish protection make it more important than ever to have current and accurate measurements.
That’s because the recently rewritten Section 316(b) of the Federal Clean Water Act, which dictates how power plants and other industrial facilities must protect fish at cooling water intakes, bases much of its applicability and compliance requirements on intake flows. A plant’s actual intake flow can determine which requirements apply and help to manage the cost of compliance.
One common misconception is that intake flows are always known. After all, plant cooling systems were designed for a specific flow, and the installed pumps were chosen accordingly. Yet in reality, most thermal power plants in operation were built more than 40 years ago. Degradation and fouling in the pump internals, condenser systems, and discharge system all happen over time. A facility’s systems may have been modified, and environmental conditions change. Taken together, these changes can potentially drop actual flows as much as 25% below design.
The potential gap between design flows and actual flows is often “out of sight, out of mind.” But documenting your facility’s flow data is a task that can be performed relatively quickly with minor disruption to operations—and has a strong potential return on investment. Accurate measurement does not require a flow meter to be installed, and is most often performed in one of two ways: through dye dilution or through multi-point velocity measurements. Whichever method a facility chooses, working with an organization that is experienced in field flow measurement will ensure that investment provides the level of accuracy necessary to achieve the desired returns.