The Deep Lake Water Cooling System
Click here to enlarge imageFor metering systems, Enwave has turned to SRB Controls Inc., of Markham, Ontario, which recommended the IFS 4000 KC Enviromag electromagnetic flowmeter (EMF), ranging in diameter from 3 inches to 20 inches, from Krohne Inc. of Peabody, MA, and Krohne Toronto, Ontario. KROHNE has been a leader in the development of magmeters since it introduced the first EMF for industrial applications in 1952.
Electromagnetic Flowmeters
“We use only magmeters, because they are economical and very reliable for a wide range in diameters and flowrates,” says Perkins. “The Krohne Enviromag meter meets our exacting accuracy standards, even when flowrates for a customer might vary from 5000 gallons per minute on a hot summer afternoon, down to only 200 gallons per minute at night or in the winter when cooling may only be needed in a single computer room.”
The Environmag meters require absolutely no maintenance and there are no mechanically moving parts. Each meter is wet-calibrated on accredited (EN 17025) calibration rigs at the factory and supplied with test certificate. Consistent results are reliably achieved with no zero point calibration, no precalibration, and no periodic recalibration.
EMF technology has a relatively simple operating principle. An electrically conductive fluid flows through an unobstructed insulating tube and through a constant magnetic field. A voltage is induced in this fluid proportional to its mean flow velocity, and this signal voltage is picked up by electrodes. Microprocessor-based electronics converts this voltage into scaled pulses (e.g., 1 pulse for every US gallon of medium flowing through the measuring tube). Enwave uses Krohne IFC 020 electromagnetic flow converters to store and aggregate data and to perform self-diagnostics.
In addition to providing billing information, the magmeters are networked over telephone lines to provide realtime information to monitor the flow to each customer. For example, if a meter indicates that a customer is utilizing unexpectedly high flow, it may be an indication that a problem exists in the building’s air conditioning distribution system or that Enwave needs to provide supplemental cooling energy by lowering the temperature of the water that it is supplying.
Enwave is connecting DLWC customers to its distribution loop at the rate of about 18 new buildings per year. Because of the wide variety of meter diameters required by different customers, it is not economical to carry any meter inventory.
“We have been pleased with Krohne’s short delivery times, allowing us to meet our project schedules with just-in-time purchasing,” says Perkins. “But most important of all is the accuracy of the magmeters. The worst thing would be to start having an argument about bills, and that’s why we are so fussy about the quality of the meters we use.”
Part of Krohne GmbH & Co., with headquarters in Duisburg, Germany, Krohne Inc.’s Canadian offices are in Burlington, Ontario. Contact: +905-319-3388, [email protected] or www.krohne.com