The operation station and the engineering station operation station are composed of two DELL computers and two displays. The computer exchanges data with the control station in real time through the Ethernet, allowing the operator to monitor the on-site working conditions in real time, such as the temperature, pressure and flow of the process gas at the inlet and outlet. , pressure difference and other parameters, unit vibration value, shaft displacement, bearing temperature; unit gas, oil, water valve, suction valve opening and oil, water system pressure, temperature and oil pressure difference. The monitoring points mainly include the shaft temperature of the air compressor, the shaft vibration, the shaft displacement, the inlet and return water temperature of the cooling water, the differential pressure of the inlet and outlet of the air compressor filter, the shaft temperature of the steam turbine, the shaft vibration, the shaft displacement, and the turbine speed. Lubricating oil temperature, pressure, air flow, air compressor outlet pressure and other signals.
While completing the system configuration, control configuration and operation information download, the engineering station can also receive the field data uploaded by the control station and display the data in real time as an operator station. In addition to the monitoring function, the operator station also has an operating function. For the air compressor control system, the main operational functions to be completed by the operator station are as follows: provide alarm prompts and interlock protection functions. In order to ensure the safe operation of the equipment, the system monitors the oil temperature, oil pressure, outlet pressure and intake air flow in real time. Once a light fault alarm occurs, the system will sound and light alarm, causing the attention of the operator; if not handled in time, A heavy fault alarm occurs. At this time, the system will interlock and stop according to the interlocking input condition to ensure the normal operation of the equipment and avoid dangerous accidents. The remote operation function of the actuator. The oil pump, main motor and other equipment can be manually started/stopped, and the interlock can be manually input. The computer automatically starts or stops the standby device according to the change of pressure and temperature signals.
The operation of the regulating valve is manual or automatic. In the manual mode, the valve is artificially controlled by its opening degree; in the automatic mode, the opening of the valve is automatically controlled by the computer, and the control parameters can be modified online. The hand/automatic state can be switched to each other, but when working in the surge zone, the computer will cancel the automatic adjustment of the suction valve, switch to manual control, and alert the operator to the attention. Intake regulation According to the requirements of the process, the compressor control uses constant pressure control. The regulated object is the outlet pressure, and the adjustment actuator is the suction regulator. When the working condition is normal, the computer automatically adjusts the intake air flow, the SV value is constant, and the intake valve size is automatically adjusted according to the change of the gas consumption amount, and the adjustment parameters can be modified. The principle is as shown.
Surge has a serious hazard to centrifugal compressors. It can cause deterioration of compressor performance, large fluctuations in process parameters, impact on bearings, collision of static components of the unit, seal damage, and a large amount of gas escape in severe cases, causing a vicious accident such as an explosion. Therefore, anti-surge control is the most important safety control in the system. The purpose is to keep the working point of the compressor within a limited range without entering the surge zone to ensure safe operation of the unit. The anti-surge control of the compressor is the vent valve, which means that the system uses the method of opening the vent valve to reduce the pressure and increase the amount of venting gas, so as to avoid damage to the equipment caused by the reverse flow of high pressure gas and repeated compression.
Conclusion The DCS completed the installation, commissioning and commissioning of the system in three months. Five air compressors were successfully driven at one time, the signal measurement and PID adjustment were accurate and reliable, and the air compressor realized Anti-surge automatic adjustment control, and has a good interlock protection function, which improves the stability and safety of equipment operation.
Through the preliminary exploration and technical preparation work, after a period of trial operation, the system is reliable, flexible, and easy to operate, and the automatic control system achieves the expected results. The entire system is stable and has achieved good economic and social benefits.
Electric Golf Buggy,Electric Buggy,Golf Buggy
Fenghua Jade Motor Co., Ltd. , http://www.golftrolley-manufacturer.com