As one of the first blogs to report on energy efficiency in CNC machining, We felt it important to post on Siemens new product the Sinumerik Ctrl-E.  This post contains specs on the product and how it can help save in electricity cost as well as aid your business in garnering a “green” reputation. According to a recent EU Commission report, industrial production accounted for 40 percent of total power consumption in the EU-27 in 2007, of which 70 percent was used by electrical drive systems. Depending on the company involved, machine tools can account for up to 68 percent of the total energy requirement. This fact makes energy efficiency in manufacturing a decisive factor in reducing plant costs and improving overall competitiveness. Siemens kept this in mind when it carried out an energy analysis of individual machine tool components with the goal of achieving significant cuts in energy consumption through Sinumerik Ctrl-Energy.

With Sinumerik Ctrl-Energy, Siemens has opened up a broad range of solutions for the energy-efficient operation of machine tools, encompassing its Sinamics drive systems and motors, CNC and drive function and PC software solutions. Sinumerik Ctrl-Energy offers energy-efficient solutions covering every aspect of the machine’s lifecycle, starting from machine design and engineering through machine operation and partial or complete retrofit. This makes Sinumerik Ctrl-Energy a broad-based platform for efficient machine management, which will benefit both the machine tool OEM and end-user.
By holding ‘Ctrl E’  on the operator panel, Sinumerik CNCs can provide a fast evaluation of the machine tool’s energy consumption and also manage energy consumption during machine downtime. Using the ‘Ctrl-E Analysis’ function, Sinumerik controls determine both the energy consumption of a drive system and the entire machine. They enable the user to analyze the amount of energy that goes into machining every individual workpiece as the basis for machining strategy improvements. The ‘Ctrl-E Profiles’ function also provides a configuration platform for the management of the machine’s energy saving modes, helping to selectively shut down specific power loads during downtimes.

FREQUENCY CONVERTERS AND ENERGY-SAVING MOTORS — THE INTEGRATED DRIVE TRAIN AS A CORE ELEMENT OF OVERALL ENERGY EFFICIENCY
The Siemens Sinamics S120 drive system permits dynamic energy management in the DC link and makes use of a highly efficient power recovery system, which initially stores generated braking energy in a DC link and optionally feeds it back into the grid rather than allowing the brake resistance to turn it into heat. Sinamics drives and Siemens motors have been designed with a clear focus on energy efficiency aspects. In this manner, integrated drive modules from Siemens reach a high efficiency rating of 97–99 percent.

With an efficiency of up to 94 percent in synchronous motors and up to 91 percent in asynchronous motors, the Siemens motor range also provides a basis for energy-efficient machine designs. In a typical machine tool, auxiliary assemblies such as hydraulic supply systems or cooling and lubrication units account for over half the total energy consumption. Energy-saving 1LE standard asynchronous motors have an efficiency rating of up to 97 percent and offer significant potential for auxiliary assembly improvement. The use of Sinamics G120 frequency converters helps adjust the speed and also the energy consumption of auxiliary systems to the level required at each stage of
the process.

POTENTIAL SAVINGS: CURRENT FLOW REDUCTION AND POWER FACTOR COMPENSATION
Sinamics S120 drive systems permit automatic current flow reduction in asynchronous spindles operating under part-load, avoiding unnecessary heat loss. The reactive power of a machine can be fully compensated using the smart infeed and feedback modules of Sinamics S120 drives, rendering costly and loss-prone reactive power compensation units on the end user’s premises superfluous.

CONTROL CABINETS ALSO HELP EFFICIENCY
Control cabinets, along with the required dissipation of heat, have a significant impact on the energy balance of a machine. Siemens can supply machine tool builders with a complete control cabinet that is designed with optimum energy management in mind. Various cooling options exist, including cold plate and direct fluid cooling, which reduce the need for air-conditioning in the control cabinet and make waste heat produced by the drive systems available elsewhere in the form of process heat.

SIZER — THE CONFIGURATION TOOL FOR ENERGY-EFFICIENT DRIVES
Sizer is the Siemens software tool used to configure energy-efficient drives. It calculates energy consumption and losses incurred with the anticipated load cycles (ramp-up, idle running, running under load, braking, cycle times etc.), as well as the influence of regenerative feedback. This allows the energy efficiency of alternative motor/converter combinations to be evaluated. Using this information, configuration of the feed and main spindle axes can be optimized in line with the process and the anticipated cyclical work flows. Sizer also helps users to avoid over-dimensioning, also in terms of infeed, and to minimize energy consumption.

A burgeoning field in all walks of life is the green, or sustainability, movement. It has made its presence known in film, politics, mass consumption and manufacturing. The green manufacturing movement has inspired a lot of companies to turn towards more sustainable and “eco-friendly” methods of production, incorporating reusability and recycling into their business plans and developing new products that can be reused, recycled or those that will have less of an impact on the environment. While these innovations are good for the earth, they can also be useful PR tools for a company’s brand image. While a lot of green initiative implementation can be more costly than their standard counterparts, often long term cost-saving is the benefit of the initial up front costs.

Geothermal Heating and Cooling

Use of standard air-source heat and coolage pumps is widespread, but use of geothermal heating and cooling systems is growing; professionals estimate that 50,000 new units are installed in the United States every year.

Geothermal temperature control involves the use of subterranean temperatures to regulate air temperature. Basically, temperature is relatively standard just a few feet below the earth’s surface, normally warmer than outside air in cold periods and cooler than outside air in hot ones. A geothermal temperature pump warms or cools air and sends it through a closed system in a building, offering temperature control. Geothermal systems can be combined with air-source pumps for a dual-source unit. These units are slightly cheaper to install than strict geothermal systems, but are less efficient. This choice depends on the location of the facility and the needs of the company. Geothermal systems generally have higher efficiency rates than air-source systems.

Unfortunately, geothermal systems are more expensive to install than air-source systems. However, they are generally more inexpensive to maintain and use, and they have life expectancies of 50+ years overall, with certain internal components estimated at 25 years. It would take a company 5-10 years to recoup the difference if they invest in a geothermal system than if they had invested in an air-source temperature control system.

Green Energy Production and Energy Saving Techniques

Another energy concern for companies is production. Many manufacturers are turning to on-site solar energy production to power their factories, buttressed by wind, hydro and landfill gas electricity. This is an effort to turn away from fossil fuels, which produce great amounts of energy, but are seen by many as great pollutants and aren’t renewable resources.

Running a factory on alternative energy can involve high investment in the initial stages. Switching to wind or hydro-generated electricity involves installing different equipment which can be costly, but long term investments can pay off.

Green Branding

One of the more intangible differences between classic and green, eco-friendly innovations is the public relations aspect. Companies can foster greater relationships with their local communities by engaging in very small scale community investment. And for customers, buying from an eco-conscious company can be paramount. And going “green” can be as simple a task as investing in carbon emission offsets. According to many experts, the unquantifiable public relations boost “going green” can afford a company is seen as leverage in today’s conscious and concerned economy and environment.

The Future

Any newsstand will feature literally dozens of articles about the green revolution, which speaks to the demand for readers about these kinds of initiatives. Regardless of global warming’s currency in popular discourse, there is certainly a growing population who are eager and willing to engage in more ecological conscious production and consumption behavior, paving a way for more green innovations.

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