In the first of a series of three columns, we look at the energy and productivity benefits achievable by installing a variable speed drive (VSD) on specific applications. This month: pumps and fans
VSD can help transport liquids safely by ensuring the motor driving a pump is running at the correct speed to maintain a safe pressure in a pipe. VSDs benefit all types of pumps including circulating water in HVAC systems, boiler feedwater pumps, industrial process cooling pumps, chilled water pumps, wastewater treatment and clean water applications.
In the UK, pumps use a total of 20 TWh/ annum, responsible for the emission of 2.7 million tons of carbon per year. Pumps represent the largest single use of motive power in industry and commerce. Since most pumps are variable torque, they benefit from the largest savings when speed control is employed.
VSDs improve system reliability, simplify pipe systems by eliminating the need for control valves and bypass lines, provide soft-start and stop thereby reducing wear and tear on the motors, and reduce leaks and bursts caused by pressure surges. All this leads to lower maintenance and life cycle costs and increases plant availability.
There are many types of fans used to move air and gasses in industrial applications, such as centrifugal and axial. Whether belt driven, or direct coupled, many can benefit from VSD control to save energy, improve processes and reduce maintenance costs.
Often air flow is controlled via a mechanical damper in the duct work, either before or after the fan. The type of damper is important as different designs effect the fan performance and load. In most cases large savings can be achieved through VSD control. Where no control is present or required, savings can still be made by reducing oversizing in the design and applying the VSDs energy optimisation feature, reducing motor losses and saving further energy.
Whether belt driven or direct coupled, VSDs can reduce maintenance costs through softstart control of the fan. Belt, gearbox, couplings and bearings wear and tear are significantly reduced, improving system reliability and availability. Where large fans ‘windmill’ while out of service, VSDs can catch these, slow and stop them in a controlled manner, rather than trying to start direct-online (DOL), which can cause huge stresses on mechanical and electrical components, often leading to premature failure. To find out how a VSD could benefit your motor-driven applications, request ABB’s Energy Efficiency & Productivity Improvement Plan by emailing [email protected], or call 07000 DRIVES (07000 374837).
ABB (ABBN: SIX Swiss Ex) is a pioneering technology leader in electrification products, robotics and motion, industrial automation and power grids, serving customers in utilities, industry and transport & infrastructure globally. Continuing a history of innovation spanning more than 130 years, ABB today is writing the future of industrial digitalization with two clear value propositions: bringing electricity from any power plant to any plug and automating industries from natural resources to finished products. As title partner of Formula E, the fully electric international FIA motorsport class, ABB is pushing the boundaries of e-mobility to contribute to a sustainable future. ABB operates in more than 100 countries with about 135,000 employees. www.abb.com