TN Hermetic Compressor for CO(2)


		TN CO₂ Compressor EnVisioneering how to make an ideal natural refrigerant—carbon dioxide—a technological reality As an example of EnVisioneering at work, Danfoss uses innovative engineering to create a compressor that functions at the high pressures necessary to make carbon dioxide refrigerant practical in both its subcritical and transcritical cycles for cooling applications.



Environmental Responsibility Carbon dioxide is a logical choice for a natural refrigerant. It is abundant in our atmosphere, has no ozone depletion potential, and insignificant global warming potential. Unlike other alternative refrigerants, CO₂ is acceptable in every country, so it is ideal for equipment users that operate globally. It is also very inexpensive, at least 75% cheaper than other refrigerants. But CO₂ hardly seems a practical option, given that in the transcritical phase of the temperature-pressure cycle, the supercritical portion occurs above 1,067 psia—72 times Earth's atmospheric pressure and only 200 psia below that of Venus. To make carbon dioxide feasible in a modern refrigeration system requires a compressor with advanced shell construction, internal leakage control, and a lubrication system that can withstand high operating pressures. The Danfoss TN compressor, by accomplishing each of these requirements, is the best technological solution for future commercial appliances, such as bottle coolers, vending machines, display cabinets, and even hot-water heat pumps!



Engineering Innovations The Danfoss TN compressor is an advanced design that meets all the demands of the carbon dioxide compression cycle in applications up to 0.4 TR (tons of refrigeration capacity). The outer shell is a new, robust design that will handle CO₂’s higher pressures. Piston rings are used to prevent internal cylinder leakage. A special piston connecting rod bearing design accommodates a smaller piston diameter and higher specific forces on the bearing. Although CO₂ systems operate at higher pressures, the compression ratio is only 3 or 4 to 1. The lower compression ratio requires a much smaller motor, which allows a very small housing, making the TN compressor a compact answer for customers seeking an environmentally acceptable design. The TN compressor’s development was recognized with the AHR Exposition’s Innovation Award in 2004. To see additional information about the TN compressor, click here