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Tech Talk




Driving Reductions in Energy Consumption


Parker Hannifin Corporation Contributes

I had the pleasure to talk with Parker Hannifin Corporation. With annual sales exceeding $12 billion in fiscal year 2011, Parker Hannifin is the world's leading diversified manufacturer of motion and control technologies and systems, providing precision-engineered solutions for a wide variety of mobile, industrial and aerospace markets. Few can have failed to notice that energy and climate change have been climbing up the political and business agenda for a number of years now. Indeed, just last month, new global targets aimed at reducing carbon emissions and making greater use of renewable technologies were agreed at the United Nations Durban Climate Change Conference 2011. "Ultimately this means reducing energy consumption by driving up its cost", argues Peter Vos, General Manager of Parker SSD Drives, "But the cost also needs to go up in order to pay for infrastructure renewal and to finance research and development into low- and zero carbon generation technologies."

With all the talk of 2020 and 2050 targets you'd be forgiven for thinking that reducing carbon emissions and energy consumption is a job for tomorrow, perhaps once scientists have invented some fantastic new technology or maybe mastered the complexities of nuclear fusion. The reality is somewhat different. If we are ever to make the quantum changes required to meet these longer term goals we need to start work today and use the technologies that are currently available to us. One such technology is the variable speed drive which first appeared in the late 1960's. Although today's drives bear little cosmetic resemblance to their forefathers, their basic principle of operation has changed very little in all that time. Any engineer who has opened a technical magazine in the past 20 years cannot fail to have noticed plenty of articles about the advantages of fitting variable speed drives to motors in order to reduce energy consumption. They are very seductive, quoting the fact that energy savings are proportional to the cube of the speed reduction and that financial payback of the capital outlay can be achieved in quick order. This is often accompanied by case studies showing how such and such an organisation has scored a real success with the installation of one or more drives. Others have explained the principles in greater or lesser technical detail. In fact it is difficult to imagine that the technology was not comprehensively picked up 10 or 15 years ago and that processing plants across the globe are now paragons of virtuous efficiency. The perhaps shocking truth is that of all the motors in industry that would benefit from a variable speed drive, 80 or 90 percent do not have them fitted! Why have drives so far failed to reach their full potential? The reasons for this are complex and multi-faceted. In some cases the payback period is believed to be too long to appease the finance department, who don't want to take the temporary hit on their balance sheet. In other instances, the disruption to production during installation is seen as too much to consider. Yet others worry that they add complexity to control systems and therefore reduce overall reliability. But most of these objections are unfounded and in reality no more than an excuse for an if it isn't broke, don't fix it' mentality. Quick win energy savings can be made on motors turning pumps and fans, here huge amounts of energy could be saved across the whole of industry simply by fitting variable speed drives. Cutting overall operating speed of such a motor by a fifth will typically save as much as 50% in energy consumption. Typically mechanical devices are used to control flow, relief valves for pumps/liquids and louvres for fans/air. This has previously been likened to driving a car with the accelerator pressed to the floor and using the brake pedal to control its speed. The motor continues to run at full speed while the output of the pump or fan is choked off, producing back pressures and other additional stresses on the mechanical elements of the system. Additionally such motors tend to be oversized for day-to-day needs, so that they have the capacity to cope with maximum flow scenarios which only happen very occasionally.

The details of energy saving vary from installation to installation and are highly dependent upon the proportions of the duty cycle that require full (or near-full) power and zero (or near-zero) power. But some fundamental principles apply, for instance a pump running at 80% speed uses only half the energy compared to one running at full speed. This can be integrated over time to show the energy savings across the duty cycle. The simple truth is that in most processing plants far too many pumps and fans run continuously at full speed, with the output regulated by vanes or valves which have no effect whatsoever on reducing energy usage. There are many arguments made to the effect that the capital investment required to install drives is so high that payback is not viable, but in most cases the cost is not as high as it first appears and in many countries drives now attract additional tax breaks. Thanks to advances in software, drives are now easier than ever to configure and use without the need of a Masters degree in Control Systems Engineering. The Parker Hannifin AC30V variable speed drive is a good example of this. As a Newcomer in the drives market, and benefitting from the latest advances in variable speed drive design, the AC30V includes a comprehensive configuration wizard built into its multi-language graphical keypad which guides users through a simple step process to configure the drive to the application in which it is to be used. A final automatic tune-up then ensures the drive is optimised for use. -No laptop or oscilloscope or multi-meter required. As far as adding complexity to existing processes, drives such as the AC30V have a host of other features that enable them to be seamlessly integrated into existing production environments with little disruption. For example Integrated EMC filters and DC chokes ensure harmonic and EMC interference won't disrupt existing electrical and electronic equipment. Integrated Ethernet communications with the option to include one of a number of popular fieldbuses enable drives to be connected to existing control systems and the ability to include the controlling software in the drive itself means that the need for additional PLC hardware can often be avoided. Vos has no doubt as to what drives manufacturers need to do to improve the take up of variable speed drives in manufacturing industry - "We recognise that as an industry we have to do more to make our drive technologies more accessible to our customers by taking away the perceived complexity and providing products that are both durable and reliable for use in any application. In developing the AC30V drive we believe Parker has taken a major step forward to meeting these challenges by engineering a product with flexibility and simplicity of use at its core. This has been achieved through the use of modular hardware design, configuration wizards and pre-configured application macros." It is somewhat inevitable that energy prices will continue to rise and the call for greater action in tackling climate change will grow ever louder as we move closer to 2020. However by taking action today and using existing commercially available technologies, manufacturing industries can take back control and mitigate the effect this will have on their businesses tomorrow. You could call it a real win, win' for all concerned. Parker Hannifin Corporation The company employs approximately 58,000 people in 47 countries around the world. Parker has increased its annual dividends paid to shareholders for 55 consecutive fiscal years, among the top five longest-running dividend-increase records in the S&P 500 index. For more information, visit the company's website at www.parker.com, or its investor information website at www.phstock.com.


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