Eastern Petrochemica

Information
 

One famous petrochemical company choose the imported brand centrifugal compressor to supply the compressed air, this imported centrifugal compressors has the advantage such as  small size , highly integration grade, high efficiency and so on. But this this type compressor's lubrication system use the plate type heat-exchanger, and after continue working , the plate  type heat exchanger start to show its weakness-- plate type heat exchanger has a high requirement of the media cleanness degree.

Feasibility  analysis for the Improvement

1. Lubrication system problem before improvement Working power is 1315kW, the rotation system made by the main gear shaft, 1st stage rotor, 2nd and 3rd stage rotor. The max speed in the 2nd and 3rd rotor can reach 25660rpm. Oil inlet temperature is 85℃,outlet temperature required 45, after two years working by the plate type heat  exchanger ,the lubrication oil temperature after cooling always close the braking line and system alarm ,the machine can not working stable.   2. Reason analysis The plate type heat-exchanger has  the advantage of small dimension, high efficiency advantage ,when it assembling into the high integration equipment ,the small size looks very nice. But is also has the disadvantage. The plate type heat-exchanger 's flow tubes fins gaps only have 3-5mm, and the cold media is the outdoors water without any filtration, so the cold water usually has a lot of impurities. After using for a while, the parts flow tubes will be blocked and this condition will reduce the heat exchange area and down the heat transfer.

By comparison,  we choose the shell and tubes heat exchanger which assembling fins side , this type heat exchanger which with low cleanliness requirement of  the media but also with a high heat transfer efficiency.

With our improvement, the lubrication oil inlet temperature is 85℃ ,after cooling, the outlet temperature is 45℃. After running 1 year, the cooling temperature is same as before.