Long-term compressor performance
Published: 15 March, 2007
The answer to this month's trouble shooting teaser is supplied by BOGE Compressors.
Q:
Why is temperature the biggest single influencer of the long term compressor and compressed air system performance?
A:
If the inlet temperature is correct then a compressed air system will look after itself. However, if too high, the long term performance of the compressor and compressed air system will be compromised as temperature affects a number of areas within a compressed air system.
When inlet temperatures are too high efficiency is reduced. Just a 4°C rise in ambient temperature will create a 1% drop in compressed air efficiency. This may sound insignificant. Consider a 100 HP compressor operating at 4oC above ambient. Based on the compressor running 8,000 hours per annum with an electricity cost of £0.07 per kW/hr, it will cost an additional £420 per annum to run.
Additionally a rise in inlet temperature will increase oil carryover. A 5°C rise in inlet temperature will increase oil aerosol carryover by 30% not only increasing oil consumption but also downstream filtration costs. As an example, a 100 HP compressor running under normal operating conditions for 8,000 hours per annum would lose around 20 litres of oil per annum. However, raise the inlet temperature by 5°C and this compressor will require an additional 6 litres of oil per annum! Increased oil consumption reduces the life of filters and the efficiency of drying and condensate collection equipment.
The life of electrical components also decreases as inlet temperature rises. Windings in motors, cabling and components will become susceptible to premature failure as a result of high ambient temperatures.
Finally, as a matter of physics, the warmer the intake air, the less efficient the compressor becomes. So output is reduced and the specific power kW/m3 is increased. Nowadays power costs are major considerations.
In summary the ambient intake air/cooling air is a critical consideration in your compressor installation. Get it right (or put it right) will save you money. That"s guaranteed.
For further information please visit: www.boge.co.uk
