On the ideal gas law
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Reciprocating compressor, three-stage compression; inlet pressure at the first stage is 2.4 MPa, temperature is 39 degrees, flow rate is 28,500 cubic meters per hour, and system pressure is 8.5 MPa. If the system pressure is to be increased to 8.7 MPa, what should be the hydrogen flow rate at the first stage? How to calculate it?
It’s best to try this within the parameters specified by the manufacturing process; that should work. Increase the inlet pressure and observe the changes in the outlet pressure. There are many factors involved; it’s not a simple proportional relationship, and gas equation laws cannot give accurate results. The suction pressure and discharge pressure specified for such equipment are parameters related to the inherent capabilities of each stage of the cooler; it is only by taking these into account that the desired product pressure, flow rate, and temperature can be achieved. If the suction pressure is increased, it will inevitably cause the unit to operate beyond its capacity, which is not advisable. Additionally, the low outlet pressure is related to the excessive usage by the users. For reference.
The difference between 8.5 and 8.7 is 0.2 MPa; as long as 8.7 does not exceed the set pressure value of the unit’s outlet safety valve, it is generally possible to increase the pressure, as there is usually a certain range allowed for pressure fluctuations under normal conditions. After adjusting the pressure, simply adjust the load for each stage according to the compression ratio. If it is necessary to calculate the amount of hydrogen, it can be estimated using the gas equation of state, based on the current temperature and pressure
When the pressure is held at 8.7 MPa, the pressure ratio of the final stage increases; the ratios of the other stages may remain largely unchanged, while the compressor’s power increases. If the above situation has little impact, no adjustments to imports are necessary.
Recently, it was found that pressure regulation is slow, whether increasing or decreasing pressure. None of them reach the specified speed. And every time it reaches the proper position, the pressure continues to change according to an upward or downward trend, and it also moves back again
I agree with what was said on floor 2: system pressure is related to the compressor outlet pressure. Generally, the system pressure is lower than the compressor outlet pressure; unless the compressor outlet pressure is not sufficient to meet the system’s requirements, the compressor inlet pressure may increase, depending on whether the compressor’s operating conditions are satisfactory.