Demands for reductions in CO2 emissions from factories continue to rise in response to global warming concerns. Such demands, coupled with the desire to reduce maintenance costs and improve plant operation efficiency, have led to great advances in converting conventional turbine-driven compressors to electrically-driven ones.
REPLACING A GAS TURBINE
For this example, “Plant M” was using a gas turbine to drive a compressor. However, the aging in the gas turbine required more frequent maintenance and brought a lot of maintenance costs. A technician from the equipment division began studying replacement of the turbine.
Replacement should be achieved by satisfying a number of conditions defined by management. These conditions included reduction in CO2 emissions, utilization of the existing installation space, and reduction in maintenance costs.
USING HIGH-SPEED MOTOR SEEMED RISKY AND IMPRACTICAL
In order to reduce CO2 emissions, the technician considered using a conventional four-pole electrical motor drive system. However, it required a speed increasing gear and more installation space. Therefore it did not meet their requirements. While a gearless high-speed motor came into his head, he thought it was not worth investigating.
“In my mind, using a high-speed motor was not a realistic option, because achievement records were still insufficient and there was a concern regarding vibration risks,” the technician says. “Use of such a motor would also increase maintenance costs. At this point, I was at a loss as to what to do, and it looked almost impossible to replace the system under these situations.”
HIGH-SPEED MOTORS ARE NOW A FEASIBLE SOLUTION
The plant’s technician continued to collect information and, hoping to get a hint for a solution, consulted TMEIC that had a proven track record of manufacturing and delivering high-speed motor drive systems to both domestic and international companies.
The sales person told him, “The risk associated with high-speed motors is no longer an issue. That’s an illusion from ten years ago. It was very difficult to design and manufacture high-speed motors but today they are already a practical proposition for us with advanced technology and abundant experience accumulated over 100 years by Toshiba and Mitsubishi Electric.”
The TMEIC sales person went on to explain that some facilities have already adopted high-speed motors, and achieved a 94 percent reduction in maintenance costs and zero emissions.
The idea of adopting a high-speed motor drive system was now looking realistic. The technician calculated its effect with TMEIC, and then found out that the initial cost could be recovered within a three-year period.
FULLY PREPARED GLOBAL SUPPORT FOR USE IN OVERSEAS PLANTS
Finally, the technician made a decision to adopt the high-speed motor. No concerns were raised after an information session, because TMEIC put together the data.
The high-speed motor was installed directly to the train, achieving increased system efficiency due to the gearless system. Significant running cost reduction was achieved and energy balance was optimized without frequent maintenance.
“TMEIC high-speed motor drive system is also suitable for use in overseas plants, because they provide full global support,” the technician concludes. “Now we are thinking about adopting motor-driven compressors for new facilities from the beginning!”
Toshiba Mitsubishi-Electric Industrial Systems Corporation (TMEIC) was formed in 2003 from the merger of the industrial systems departments of Toshiba Corporation and Mitsubishi Electric Corporation. TMEIC Corporation, headquartered in Roanoke, Virginia, designs, develops, and engineers advanced automation, large AC machines, and variable frequency drive systems. TMEIC Corporation specializes in the metals, material handling, oil and gas, solar power, mining, paper, and other industrial markets worldwide. We drive industry. For more information, visit www.tmeic.com.
MODERN PUMPING TODAY, December 2017
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