Control Method of Constant Pressure Air Supply of Multistage Centrifugal Air Compressor

Abstract

The invention discloses a constant pressure air feeding control method for a multistage centrifugal air compressor. The method comprises the following steps: 1, combining performance simulation and experimental data to obtain a compressor performance curve according to design parameters; 2, determining an unloading pressure value and a reloading pressure value, and combining the first step to determine a surge area, a guide vane regulating area and a vent valve regulating area; 3, arranging P setting and dead zone range during normal operation, and generating a regulating signal; 4, entering a full constant pressure control regulating mode if Pcurrent is more than Preloading and less than Punloading, and entering a step 5; entering a forced unloading mode and entering a step 6 if Pcurrent is more than Punloading; entering a reloading mode and entering a step 7 if Pcurrent is less than Preloading; 5, determining a regulating interval, determining a PID (Proportion Integration Differentiation) regulating parameter, and regulating the pressure value through PID; 6, totally opening the vent valve, regulating IGV (Inlet Guide Vane) opening to enable Icurrent to be equal to Imin, and entering a full constant pressure regulating mode; and 7, regulating the IGV opening to enable Icurrent to be equal to Imin, totally opening the vent valve, regulating the IGV opening again to enable Icurrent to be equal to Imin, and entering the full constant pressure regulating mode.

Description

technical field [0001] The invention relates to the technical field of control of centrifugal compressors, in particular to a control method for constant-pressure air supply of multistage centrifugal compressors. Background technique [0002] Multi-stage centrifugal compressors are widely used in petrochemical, air separation and pharmaceutical engineering to provide industrial gases. In many applications, constant pressure gas supply is required. In industrial sites, due to process and other influences, As a result, the gas consumption often changes; in addition, the length of the pipeline, the size of the gas storage tank and other factors also cause the speed of the pressure change of the compressor to be very different due to the change of the gas consumption in different occasions. It brings great difficulty to the constant pressure control of the multi-stage centrifugal compressor. In addition, during the control process, the switching speed of the guide vane and the v...

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Problems solved by technology

[0003] The purpose of the present invention is to provide a multi-stage centrifugal pump to solve the problems in the prior art that it is impossible to provide constant gas supply to the site of gas consumption, the control of constant pressure gas supply is difficult, and overcurrent shutdown and surge shutdown often occur during the control process. A control method for constant pressure air supply of a type compressor. This method determines the control and adjustment area map of the compressor according to the design parameters of the compressor and experimental data, and then judges which adjustment area is currently in according to the current pressure value and current value, and adjusts the inlet through PID. The opening of guide vane IGV or vent valve BOV achieves the purpose of constant pressure air supply

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