What is the effect of increasing the inlet pressure of a compressor?

Is the compressor reciprocating or diaphragm type? Increasing the intake pressure generally requires an increase in displacement, leading to higher power consumption and greater piston force. Other parameters need to be determined based on the actual operating conditions. However, given such significant changes, it is recommended to consult the compressor manufacturer; having the manufacturer assist in reviewing and calculating these values would be advisable. Personally, I think that in order to increase the intake pressure while keeping the exhaust volume unchanged, the compressor would need to be modified. For reference only!

In the case of a reciprocating type, the exhaust temperature will decrease while the pressure between stages will increase; it is necessary to take into account the set pressure value of the safety valves between stages. However, when there are significant changes in operating conditions, the gas valves need to be recalibrated. As for the displacement, it can increase the backflow rate.

The piston force needs to change, the air valve must be adjusted; the temperature change will not be significant, the outlet diameter needs to be increased, and the power consumption remains roughly the same. You need to contact the manufacturer of this compressor and ask their design department to review it and provide suggestions.

To change the compression ratio, the air valves need to be replaced, the safety valve must be recalibrated, the displacement will definitely increase, and the outlet pipe needs to be enlarged. For safe operation, it is best to contact the manufacturing unit for advice.

First, it is necessary to determine whether this design pressure corresponds to the lowest possible intake pressure. Increasing the intake pressure has the greatest impact on the pressure at the first-stage outlet, with no changes in the other circuits. A higher intake pressure leads to a lower compression ratio, which in turn results in significantly lower exhaust temperatures at all stages; the temperature of the fillers at each stage also decreases, while the exhaust volume increases. The extent to which the intake pressure can be increased depends on the safe operating pressure at the first-stage outlet – too high a pressure can cause the pressure at that outlet to become excessively high, whereas the exhaust pressure at the second stage can be controlled by the system. Second, to maintain a constant exhaust volume, it is possible to add circuits between the stages: the output from the first stage can be returned to the input of that same stage, and the output from the second stage can be returned to the input of the first stage

It is of the piston type. The exhaust pressure at the second stage can be controlled at a certain value through the process system. By increasing the inlet pressure, the exhaust pressure at the first stage will certainly increase, but the exhaust pressure at the second stage remains unchanged. For a given amount of gas, I think the power required should be lower. For example, the work done per unit time in compressing 100 cubic meters of hydrogen from 1 kilogram to 3 kilograms is it more than the work done per unit time in compressing the same amount of hydrogen from 2 kilograms to 3 kilograms? I’m still a bit confused; I hope the more experienced ones can give me some advice!

A sudden drop in the inlet pressure of the compressor has an impact on the compressor

To increase the inlet pressure, it is necessary to determine whether the thrust exerted by the piston rod can be withstood; this is exactly what we did. As a result, the piston rod breaks more easily than before, but nothing else seems to be an issue.

You can take a look at the calculations related to compressors in the selection of process equipment, which is covered in Part 2 of the chemical process design prepared by Sinopec Group; there is an example problem there that can help solve your issue, haha!

What was said upstairs is correct: increasing the inlet pressure has little impact on the compressor’s power, as the outlet pressure must remain constant. When the compressor’s discharge volume increases, it is necessary to add a return pipeline from the outlet to the inlet in order to regulate the flow at the outlet and achieve pressure control. There are a few points to note: 1. Increasing the inlet pressure reduces the compression ratio of the compressor, which in turn lowers the exhaust temperature and the specific compression power, meaning the power required to process a unit mass of gas decreases. 2. The strength of the compressor’s inlet valve needs to be increased. 3. The unbalanced forces on the piston rod increase, so its strength also needs to be enhanced

I don’t know much about compressors, but after reading the above discussions, I found them very helpful.