In automotive manufacturing, more plastic parts are used every year. The parts are designed to be uniform, sturdy, good looking, easy-to-install and cheap to ship. They are manufactured by injection molding and come from molds kept at precise temperatures by industrial chillers.
Cars and printing presses each contain parts precision machined to tolerances as close as a few ten thousandths of an inch. The machine tools that mill, grind, and drill those parts need their cutting fluids - the lubricants that are constantly delivered to the cutting surface - delivered at carefully controlled temperatures, again a role in which the chiller is critical.
Indeed, the compressors that power industrial chillers are themselves machined by tools whose cutting action is cooled by industrial chillers.
THE VARIABLE OPTIONFor a number of years, variable-speed technology has been offered for users of industrial chillers as well as the chiller manufacturers.
For example, Danfoss Maneurop compressors can be optimized for variable-speed operation. Variable speed, when applied to a refrigeration compressor (or one used for air conditioning), acts to always match the compressor output to the demand for cooling. Thereby, the compressor always runs at the speed required to deliver the cooling needed to reach the target temperature, and no faster. Much energy is saved. The alternative is to introduce hot gas into the cooling circuit to control the temperature.
Variable-speed compressors are also money-savers because they run all the time. Running all the time might not seem like the best way to go, but if little energy is being used, or just the right amount, then running the compressor constantly actually extends its service life. This is because the stresses that are attendant to stopping, and more particularly to starting, don't occur. Starting and cycling on and off are the most life-limiting normal events in a compressor's service time.
Because of the energy efficiency and extended compressor life made possible by variable-speed operation, Danfoss has been able to enhance the designs of many of its compressors to make them suitable for high-efficiency variable-speed operation over an extended capacity range. Applications for these compressors range from water coolers to vending machines to home refrigerators and freezers, in air conditioning and industrial process systems.
For more information, contact www.danfoss.com.
Publication date: 05/01/2006