Axial power of centrifugal compressor

It is related to the material being transported and the outlet pressure

The energy required to drive the compressor gas: large centrifugal compressors are driven by prime movers such as steam turbines or internal combustion engines. The power transmitted at the shaft end of the prime mover accounts for the mechanical losses in the transmission components such as the compressor bearings, gearbox, and couplings, as well as the power needed within the compressor itself. Internal power refers to the power consumed by the compressor rotor on the gas. The compressor rotor transfers energy to the gas through an impeller. In addition to doing work on the gas, the impeller also incurs power losses due to the friction between the outer surfaces of its disk and shroud, as well as its rim, and the surrounding gas; there are also leakage losses resulting from high-pressure gas at the impeller’s exit leaking back to the low-pressure side of the impeller. For the entire compressor, the impeller converts the work done on the gas into three components: increasing the static pressure energy of the gas (compression work), thereby raising the gas pressure from the inlet pressure to the outlet pressure. Increase the kinetic energy of the gas. Under normal circumstances, the increase in kinetic energy is small and can often be ignored. Overcome the flow losses of air currents within the stage. This portion of the flow loss refers to the flow losses that occur within the impeller and in the stationary components of the stage, such as the suction chamber, diffuser, bends, return vessels, volutes, etc. In summary, the medium-power consumption in the compressor stage consists of five components: an increase in static pressure energy, changes in kinetic energy, flow losses, wheel friction losses, and leakage losses. However, only the increase in static pressure energy is useful for raising the pressure of the gas.

It’s impossible! Under other identical conditions, the greater the mass flow rate, the greater the shaft power ； The greater the molecular weight of the gas, the greater the shaft power.

It is related to the temperature and pressure conditions at the inlet and outlet of the compressor, as well as the composition of the material at the inlet (primarily corresponding to density).

But in fact, the equipment data sheet from the design institute does show a high flow rate and a high molecular weight; yet the resulting shaft power is actually low