May 2019

MOTORS SUPPLEMENT n four priorities for an alternative motor-and- drive system. The new system would have to be able to: n regulate cold water temperatures throughout its operating range during the off-season, especially at low propeller speeds; n communicate with a central management system via Ethernet; n achieve higher levels of energy efficiency; and n reduce maintenance operations and costs. Jacir, a specialist manufacturer of cooling towers for industrial and air-conditioning applications, set out the specification as part of a technical file that it presented to ADP before the contract for the new drive system was awarded. Working with a long-term partner, the motor manufacturer WEG, it performed a complete upstream study of the tower structure to ensure the adaptability of the proposed solution. The study recommended using five direct- drive permanent magnet motors in conjunction with variable-speed drives. This combination, it said, would deliver high efficiencies, constant torque over the entire speed range, and longer service lives than the original installation. By coupling the motors directly to the cooling tower fans, it would be possible to eliminate the need for a gearbox. The new system would also use less energy, and would regulate the airflow more precisely, helping to overcome the mechanical issues and the need for recurring interventions by inspection and maintenance personnel. ADP gave the go-ahead for a system consisting of WEG WMagnet permanent magnet motors used in conjunction with WEG’s CFW11 variable-speed drives. Together, they deliver 52kW of power to rotate the fans at 380 rpm. A new support structure was produced to accommodate the new motors. To meet the requirements of the standard water treatment test procedures for legionella, the structure was manufactured from 316L stainless-steel. The new installation was designed in accordance with European Ecodesign regulations – specifically, Directive 2005/32/EC, which establishes a framework for eco-design requirements when using energy-consuming products. The new system has a power rating of just over 200kW against almost 400kW for the original geared motor and VSD combination, and is operating at a much higher efficiency. The reduced energy and maintenance costs have resulted in a rapid return on investment. “Our thermal performance is now much better,” Dandeville reports. “In fact, we estimate that annual electricity consumption has halved.” He adds that since installing the permanent magnet motors, “we’ve noticed that the temperature regulation of the basins no longer generates a saw-tooth profile – it remains constant. We are now going from 0–50Hz and from 0–380 rpm without any concerns. We’ve also seen a significant reduction in noise and vibration from the cooling towers, while the structure of the towers is no longer subject to jolts when the propeller starts or accelerates. “The technology is very intuitive and user- friendly,” Dandeville remarks. “Since installation, we’ve not had to alter the program established at the beginning.” ADP has already placed further orders that will once again call on the combined expertise of WEG and Jacir. n The cooling towers at Charles de Gaulle airport are now being driven more economically and reliably by direct- drive permanent magnet motors ecivreS,selaS hceMdnaecnanetniaM, DON’T K Contact EMO gnireenignElacina EEP ON GOIN y for all our Electric G ROUND A Motor and Automati ND ROUND ron elated needs @selas ad7,yadasruoh42 nosevlesruoedirpeW erdnasrotubirtsidera xesraey-03revohtiW enilnOsrotoMcirtcelE m-cirtcele .raeyasyad563,keewasy naecneirepxeegdelwonktcudorpruo amrojamforebmunegralarofsrelles otuadnarotomcirtceleehtniecneirep nuNnidetacolssenisubnurylimafasi lno.sroto –edivorpewtahtecivresehtd .srerutcafun ewseirtsudninoitam .erihskciwraW,notae 67420 eni 338089