Roissy airport (source:Wikimedia Commons)
WEG, a global supplier of electrical equipment and automation solutions, in partnership with JACIR, a specialist in the manufacture of cooling towers (TAR) for industry and air conditioning, has equipped the cooling towers of the ADP group in Roissy with a high-performance solution.
JACIR, a long-standing partner of WEG, recommended the installation of five W22 Magnet electric motors to replace the geared motors used until now in order to solve the problem of failure and maintenance costs of the ADP group's cooling towers.
The failures encountered were related to the fact that the variable speed drive combined with a standard motor with gearbox caused overheating when low rotation propeller ventilation was required.
In order to avoid motor overheating, the drive's operating range was defined from 22 to 50 Hz with a standby time below 22 Hz and an oil lowering affecting gear lubrication when the gearbox is restarted.
"The loss of operation of the two cooling units linked to the failed TARs (7 MW per TAR) two to three times a year was becoming very problematic for our production," explains Gérard Dandeville, Maintenance Manager at ADP. "In addition, these breakdowns generated significant maintenance costs of up to €15k, including spare parts.
Four priority axes have been defined by the ADP Group for the choice of an alternative solution: regulating the cold water temperature and operation throughout the operating range in the off-season, including at low speed, communicating with the JWG via Ethernet protocol, reducing maintenance operations and costs and meeting new standards for motor energy efficiency.
Roissy airport cooling control room
W22 Magnet electric motors were able to meet these requirements perfectly with high efficiency, constant torque over the entire speed range and longer service life. This technology of motors directly coupled to the propeller (thus allowing the elimination of the gearbox) responded in all respects to the problem of the ADP group with motors that consume less energy and are much more precise in airflow regulation to overcome frequent mechanical problems and recurring inspection and maintenance interventions.
The solution consisting of W22 Magnet motors with CFW11 drives allows the system to deliver power from 52kW at 380rpm. This energy-efficient operation allows the ADP group to minimize its energy consumption.
To specify this WEG solution, JACIR assembled a technical file presented to the ADP group before the project was awarded. A complete study of the tower structure was carried out upstream by JACIR to ensure the adaptability of the proposed solution. In this document, JACIR and WEG proposed not only a unique and innovative solution but also a real solution to the ADP group's problems and a long-term vision of reducing the total operating cost, and demonstrating a real interest in the final energy efficiency of the ADP group's cooling towers.
A new motor support (chair and chassis) has been manufactured in 316L stainless steel to meet the water treatment procedure required for Legionellosis measurements.
"Since the installation of permanent magnet motors, we have noticed that the regulation of the basins is no longer carried out at a sawtooth, the temperature remains constant," comments Gérard Dandeville, "We are now going from 0 to 50 hertz and from 0 to 380 rpm without any concern. We have also seen a significant reduction in TARS noise, vibration, and the tower structure no longer undergoes jolts during starts or accelerations of the propeller's rotational speed.
Roissy Airport TAR units
The entire WEG solution for the ADP Group's cooling towers has been designed in accordance with the European ECODESIGN regulations (Directive 2005/32/EC establishing a framework for the setting of ecodesign requirements for energy-using products).
The ease of use of the variable speed drives was also a key factor in the adoption of the solution proposed by WEG
To support the teams in charge of regulation, full training was provided when the equipment was commissioned following assembly operations.
"The whole thing was very simple and in French, it's great! The technology implemented is very intuitive and user-friendly. Since its installation, we have not had to intervene on the programming established at the beginning," says Gérard Dandeville.
The support throughout the project and the close collaboration between WEG and JACIR made it possible to complete the project on time. The synergy between WEG and JACIR, combining JACIR's expertise in the field of cooling tower with that of WEG in the field of motorization and its control, has also made it possible to offer the ADP group an efficient, flexible and effective solution with a much lower installed power than the original one (just over 200kW for nearly 400kW previously, with a much higher overall efficiency) Taking into account the energy savings achieved and the reduced maintenance costs, the return on investment has been very rapid.
"It was a well done deal, on time, and our thermal performance is much better: we now estimate an annual electricity consumption envelope halved. " adds Gérard Dandeville, who has already placed other orders with the partner duo WEG and JACIR.