Relationship between load and flow rate of reciprocating compressors
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I have a four-stage, four-row, M-type symmetrically balanced double-acting piston compressor manufactured by Shenyang Yuanda. The load control is carried out through an intake valve unloader, which is controlled by a load switch that has three settings: 0%, 50%, and 100%. The corresponding states of the intake valves are as follows: 0% – all of the valve plates are pressed down by the pushers, resulting in zero load on the unit; 50% – half of the valve plates are pressed down, giving the unit a 50% load; 100% – none of the valve plates are pressed down, allowing the unit to operate at 100% load. My question is: does the flow rate correspond to each load level in a proportional manner?
The load of the compressor referred to is the flow rate.
Power P = RQ(273 + T) * ln(P_outlet – P_inlet); the greater the power, the greater the load. When the inlet and outlet pressures are constant, the load is proportional to the inlet flow rate.
Does Q refer to the inlet flow rate? I’d like to ask gently: is there any specific relationship among outlet pressure, inlet pressure, and inlet flow rate?
:) It was explained very clearly upstairs: the greater the power, the greater the load. When the pressure at the inlet and outlet is constant, the load is proportional to the inlet flow rate
You can imagine the hospital syringes we used as kids; the thicker ones definitely have a higher flow rate than the thinner ones.
“It goes without saying that the greater the power, the greater the load. It is also clear that when the inlet and outlet pressures are constant, the load is proportional to the inlet flow rate, as can be seen from the formula above. What I really want to ask is: 1. The relationship between outlet pressure and inlet flow rate； 2. Relationship between inlet pressure and load ； 3. Relationship between inlet pressure and outlet pressure ； 4. Relationship between inlet pressure and inlet flow rate ； Additionally, I would like to know the origin of the formula above; whether it is authoritative remains to be proven.
The load changeover switch has three settings: 0%\50%\100%, which are the signals provided by the compressor’s load control system. However, the actual performance of the compressor does not necessarily follow a perfect proportional relationship with this control signal, and there is generally no feedback regarding the load. However, a flow indicator can be used to determine whether it is working properly.
The original poster would like to ask whether the compressors produced by Yuanda are operating properly, what medium is used for compression, how often the piston rings and support rings need to be replaced, and whether Holberg rings are used
Adjusting the inlet valve is to save energy. Without inlet regulation, when reducing the flow rate, one can only turn on the reflux; the compressed gas returns, and it has to be cooled before being compressed again, which results in waste. But with inlet regulation, backflow is avoided. Regarding the so-called load, for reciprocating compressors, the effect of pressure is much greater than that of flow rate.
Please note that the piston in the compressor cylinder of my unit is double-acting. The adjustment of the compressor’s load is achieved by introducing instrument air into the unloader, which in turn presses down the suction valve plates. The only control element in this system is the solenoid valve for the instrument air; through this solenoid valve, it is possible to make half of the suction valves function normally while the other half remain open. This corresponds to a 50% load level, and similar principles apply to 0% and 100% load levels.