Multi-stage centrifugal compressor constant pressure control device based on PLC

Abstract

The invention discloses a multi-stage centrifugal compressor constant pressure control device based on a PLC. The multi-stage centrifugal compressor constant pressure control device based on the PLC comprises the PLC. The PLC is respectively connected with a touch display screen, a first AI module, a second AI module, a DI module, a DO module and an AO module through signal lines. The first AI module is connected with a vibration meter, an inlet-outlet water temperature sensor and a motor ampere meter. The second AI module is connected with an inlet-outlet pressure sensor, a lubrication oil pressure sensor and a lubricating oil temperature sensor. The DI module is connected with a filter pressure difference switch, an oil pump overload controller, a compressor outlet valve feedback device, a main motor soft-start control cabinet and a scram button. The DO module is connected with a compressor outlet valve, a lubricating oil system and an outlet guide vane controller. The AO module is connected with a compressor outlet emptying regulating valve and a guide vane rotating speed regulating device. The multi-stage centrifugal compressor constant pressure control device based on the PLC achieves constant-pressure control over a multi-stage centrifugal compressor system, ensures energy-saving operation of a high-power compressor unit and can greatly reduce early investment.

Description

technical field [0001] The invention relates to a compressor control device, in particular to a PLC-based multistage centrifugal compressor constant pressure control device. Background technique [0002] The multi-stage centrifugal compressor has a series of advantages such as small size, large flow rate, light weight, high operating efficiency, less wearing parts, no oil and gas pollution, uniform gas supply, stable operation, and good economy. Therefore, it is widely used in iron and steel, chemical industry, electric power, shipbuilding and other industries. In the West-East Gas Transmission Project, centrifugal compressors are used in the whole line. [0003] Multi-stage compressors are designed to output a constant air source, so constant pressure output is the focus of unit control. It can ensure the stable and energy-saving operation of the compressor under the condition that the user's air consumption load is constantly changing. [0004] At present, the control m...

AI Technical Summary

Problems solved by technology

For frequency conversion and voltage regulation, its advantages are energy saving and good output pressure constant performance, but its disadvantages are high cost, and the harmonic impact of high-power units on the power grid cannot be ignored

The advantage of achieving constant pressure output through the outlet regulating valve is low cost, but the disadvantage is large energy loss and large fluctuations in pressure output

Surge is detected by a single pressure switch, not stable enough

It is easy to generate false positives and false positives, and once the false positives are reported, the unit will be shut down, which will easily have a great impact on the continuous production of factories and mines

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