Calculation of centrifugal compressor efficiency

I’m also looking for information on this topic; thank you! ! !

Hehe, calculation. Firstly, accurate measuring instruments are required, as well as a display on a computer to show the trends; at the same time point, the pressure, flow rate, temperature, current, voltage of the gas medium, as well as the temperature, pressure, and flow rate of the cooling water. There is also the actual power of the shaft power for each compressor. These factors may provide the conditions required for calculation, and there are specific formulas for such calculations. It’s too complicated; probably not very useful. It seems that paying attention to energy consumption is more important than focusing on efficiency. It’s just casual talk, for reference only.

The efficiency of centrifugal compressors depends on many parameters, such as speed, compression ratio, and inlet temperature. These parameters change over time, so it is meaningless to calculate efficiency in that way. As mentioned above, energy consumption can be calculated based on the instantaneous power consumption and flow rate.

Is there a power design for centrifugal compressors?

This post was last edited by lupg on 2022-5-2 at 15:49. 1. Evaluating existing compressors seems to be better described as calibration. 2. The efficiency of centrifugal compressors is influenced by various factors, among which the polytropic efficiency accounts for a significant portion of the total efficiency; therefore, the error in estimating the compressor’s shaft power should not be large. Other influencing factors are determined by the manufacturer. 3. One method for determining polytropic efficiency is by using the polytropic index and adiabatic index, which requires accurate data on the gas properties. 4. Another method for determining polytropic efficiency involves using the inlet and outlet parameters (P, T) of the compressor along with the gas’s adiabatic index k; this also requires precise operational parameters and gas property data. 6. Regarding the power design requirements mentioned by the friend on floor 6, as a user, one can follow the approaches outlined above; once the efficiency is determined, it becomes easy to calculate the shaft power. But if the person on the 6th floor is involved in compressor design, that’s a different situation; many data points cannot be provided. Even according to professional books, many parameters are given as ranges, and it takes experience and product testing to determine whether these ranges are appropriate. 7. Gas compressors involve the properties of gases, and time is spent collecting data on these properties as well as operational parameters on-site; the calculation process itself is quite fast. 8. Find some professional books on compressors and search for calculation methods online; there is a lot of information available. There are even specialized websites that offer online calculations, but their use comes at a cost. A few days ago I visited one such website; I recall that the fee for calculating centrifugal compressor parameters was 4.9 yuan per hour ； 19.9 yuan/day ； 59.9 yuan/week ； 199.9 yuan/month ； 1,999 yuan per year – a tight budget. Unwilling to pay out of pocket for official work.