[Mobile Equipment Technology Edition] Daily Question 201709026 Screw Refrigeration Compressor

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This post was last edited by YORK Industrial Refrigeration on 2017-9-29 08:38. From now on, in order to strengthen exchanges with friends, we have launched a [Daily Question] activity in the Animal Equipment Technology Edition. We hope that everyone will actively participate and make progress and improve together! ! ! award: Actively participate in 3 fortunes and answer 10-15 fortunes intact. This question is valid for two days. No marks will be given for more than two days. What is the aspect ratio of the screw in a screw compressor? The aspect ratio refers to the ratio of the axial length l of the compressor screw to the screw (nominal) diameter D0. And record it as λ≤l/Do. The general design selection range is between λ = 0.9 and 1.5, developing towards a smaller relative length. When the exhaust volume is the same, a machine with a smaller length-to-diameter ratio λ has a larger screw diameter and a larger suction and exhaust orifice area, so the gas flow loss is smaller. Machines with a small aspect ratio make the screw shorter and thicker, and its moment of inertia increases, giving the rotor good stiffness and increasing the reliability of operation. In addition, from the overall structure point of view, with a shorter screw rotor, it is possible to connect two screw sections in series on one shaft, making the overall structure compact. It should be pointed out that higher values ​​are only used for compressors with large displacement. This is especially obvious for oil-injection machines, because the screw diameter is inconvenient to be too large. In order to obtain the required displacement, some machines even have to use extra long leads (aspect ratio as high as 2.0 or more). ================================ Event promotion: Petrochemical Zone---"Brain-expanding" activity on new energy-saving ideas (the second phase of the activity is in progress) http://bbs.hcbbs.com/thread-1666758-1-1.html (Source: Haichuan Chemical Forum Network) "My Technical Transformation of Coal Chemical Industry in 2017"” http://bbs.hcbbs.com/thread-1786290-1-1.html (Source: Haichuan Chemical Forum Network)