Jigang 105000 air compressor anti-surge control design and application Liu Zhen Jinan Iron and Steel Group Corporation Automation Department, Jinan 250100 design ideas are also applicable to the design and implementation of compressor system automatic control.
The monitoring system of the unit adopts 01 630000 of Japan Yokogawa Corporation, and the system is mainly composed of the process controller wind 5 engineering station operation station. 03 Complete the functions of data acquisition data processing and field device control; the engineering station and the operation station are set in the main control room. 2% programming training to deal with the real-time monitoring of the surge of the 3 function air compressor to the abnormal situation of the air compressor; the pressure of the brother 1 is higher, and the flow rate is smaller. When this relationship is beyond the extremes of the brothers, the crew is violently shaken. Surge is severely destructive to the unit. Must be strictly guarded. Anti-surge control is achieved by adjusting the flow pressure so that the unit can avoid this area. Each unit has a surge line. This is an inherent feature of the unit. It is a curve corresponding to the outlet pressure and the outlet flow function obtained by the on-site measurement correction. When the unit is close to the curve, the vent valve is opened to relieve the pressure, so that the unit runs away from the danger zone.
1 system requirements for control purposes, 0 and the execution control algorithm cycle is not more than 10, 1 optimal cycle is 50 in the implementation process, combined with the characteristics of 3000 and take into account the overall situation, the response period of the surge control control function block Software requirements for 10 software requirements system with signal definition setpoint count calculation generator deviation control response line offset exit pressure control input control 1 control manual control gradient control asymmetric output speed limiter ramp generator anti-asthmatic Vibration control and other functions.
Operator interface controller panel manual search button control parameter calibration = 2 control function generates anti-surge curve function According to the on-site measurement and correction, the following surge function relationship is obtained. 7.5394 type 2 is the maximum allowable outlet pressure, which is converted into outlet pressure. The span amount is converted into the percentage of the full flow range of the outlet flow difference by the differential pressure value after the temperature of the open square.
The anti-surge curve is obtained by shifting the surge curve to the right by 10, as a function of the function generator. This function is realized by the arithmetic function block 01. The maximum allowable pressure value at the helium flow rate is obtained. This value is the set value of the pressure search, and the pressure is theoretically controlled below this value.
Anti-surge curve
Anti-surge line offset function When the air compressor occurs every time the alarm must be realized, the anti-surge line of the Jigang 106000 air compressor anti-surge control design and application Liu Zhen automatic correction, corrected anti-surge line 2.
If, under certain abnormal conditions, the actual pressure is converted into the difference between the percentage of the outlet pressure range and the anti-surge setting pressure, the threshold value is 30. The system detects the surge period. The surge counter plus anti-surge line will automatically shift. In this case, after the air compressor is running for a period of time, the surge curve moves down due to factors such as dirty rotor. Whenever there is a surge, the anti-surge line is shifted to the right by 1 =>=2.0675, but it can only be moved up to 5 times. If it exceeds 5 times, the original measured surge line is not suitable for this unit and must be re-corrected. It is worth mentioning that the crew must measure the surge line under no-load conditions.
A job 1 button is provided on the control panel when the operator presses the button. The anti-surge line will go to the initial measured curve. Similarly, the surge counter is cleared.
The anti-surge control deviation dynamically increases the critical line of the anti-surge control deviation.
The deviation of the team vibration control is increased by 2 in the month. If the working point of the compressor is moved to the left of the critical line between the anti-surge line and the surge line, The surge control deviation 2 is doubled, and the outlet vent valve is opened relatively quickly. Quickly return the operating point of the unit to the safe area. After the modification, the anti-surge control deviation 2 of the 0 regulator is calculated as follows: 2.0675, the working point is located on the left side of the critical line, when the working point is on the right side of the anti-surge line, the unit works in the safety zone, and the outlet vent valve Fully off when the operating point is between the critical line and the anti-surge line. Still, the regulator accepts the actual deviation 2. Out 1 is vented open; when the operating point is to the left of the critical line. The unit works in the danger zone, the 10 regulator accepts the net with a small bias force 2, the outlet vent valve opens the pressure relief faster, and the unit returns to the safe zone.
When the unit is operating in an area where the outlet pressure is relatively high, the outlet pressure is limited. Let it not exceed the maximum allowable pressure value, the outlet pressure control line 1. This can be compared with 4 and 3 by another outlet pressure control, and the larger deviation is sent to the regulator, that is, when the corresponding outlet vent valve is required to be opened at the maximum The deviation is input to the controller so that the anti-surge valve acts both to prevent surge and to regulate the outlet pressure.
Automatic manual switching and control function When the controller is in the state of automatic adjustment, the operator can also manually intervene the opening of the outlet venting valve, but the manual is performed within the automatically defined range. Manual control only allows the anti-surge valve to perform more than the opening required by the 1 controller. For example, when manually closing the door, the compressor cannot be put into the surge zone, so it must be limited by the automatically adjusted output. This function can be realized by high-selection. Only when the manual control signal is higher than the automatic control signal, the bit signal manually input by the operation is output to the outlet for venting. Otherwise the manual will not work.
The gradient 1 of the control deviation signal refers to the rate of change of the control deviation of 2 unit time, which is continuously calculated and controlled. If the following conditions are met and the output value of the controller is ä¼²ã‘匦æœè° , the distance from the actual response line to the anti-surge line must be within the given value, which is specified as 22 for the control deviation at the given control deviation 1 The gradient unit time rate of change, the second must exceed the given limit. That is, the working point is realized by approaching the anti-segment function block at a relatively fast speed.
If the operating point is in an area that satisfies both of the above conditions, an increment of 5 must be superimposed on the output value of the controller, ie, the output value after 1 = r + symmetric output function. The anti-surge process of the air compressor is controlled by The opening and closing of the outlet venting valve is realized. The opening and closing of the venting valve must be realized at different speeds. It is realized by two ramp generators with different slopes. The slope of the open ramp generator is set to 10081008 per second. The maximum output of 100, that is, the output signal of the anti-surge adjustment, is not limited when the valve is opened. The process of fast opening is realized; the slope of the off-wave generator is set to 2. that is, the output of the anti-surge transmission, 74, when the door is to be closed, it must be limited to close the valve at a rate not exceeding 23, achieving slow The process of closing. Ramp wave
Valve opening degree In the realization of this function, there is a mutual switching between the open ramp wave and the off ramp wave, and it is necessary to fully consider the bumpless switching between them, when the ramp wave is made for the moon. The output of the 1 oblique wave also works. The output of the ramp-up wave must be tracked in real time; likewise, when the ramp-off is applied, the ramp-wave must also be tracked for its output value.
8 Loading and unloading function of the air compressor The loading and unloading of the compressor is realized by turning off or opening the outlet venting valve. The slope of the loading and unloading determines the loading and unloading of the valve air compressor with two switching signals (1) and coming. Liuyi is not 1=1 air compressor main motor is powered, 0=0 air compressor main motor loses power, Xian 0=1 air compressor is normally loaded, he knows = åž press unloading, long, =, and =, switch to, he = 1 and Chan commit = 1 air compressor starts loading when driving, from 04 = 1 slave = knife to milk = 1 and = 0 air compressor starts to stop before normal shutdown = air compressor Accident, the main motor with load parking loading and unloading valve action rate is limited by two ramp generators, the slope of the two ramp generators is currently set to 1 second, the purpose of taking two ramp generators is to achieve Different rates are required for loading and unloading during working conditions. The ramp generator accepts the milk and the scent, the signal, when the singer =, when, cum, does not work, that is, the main motor does not start the loading signal does not work, when the compressor runs to the above-mentioned strip, the slant wave The generator works, closing the vent valve at a rate of 1 second until it is fully closed, achieving a slow loading process; when the compressor is running to the above-mentioned strip, the ramp-wave generator is activated, and the venting is turned on at a rate of 1 second. The valve, until fully open, achieves the normal unloading of the compressor before unloading, the ramp generator tracks the output to the valve's anti-vibration control signal, when the state of the can changes from 1 to state 0, the unloading begins, ramping The generator begins to generate a closed ramp from the actual valve position.
The output of the ramp generator is compared to the anti-surge + symmetrical output. The upper one is used for the control of the vent valve by the high selection function block. The loading and normal unloading of the air compressor is a slow process, but it must be in the event of an accident in the anti-surge 3 compressor. That is the first case. The upper motor is negatively loaded and stopped, and the vent valve is instantaneously fully open without a ramp wave.
The loading and unloading process is as follows 6.
Vent valve lift v.
3 Conclusion This system has been successfully monitored by air compressors in real time, forming a strict protection system for the entire unit. Since it was put into operation in 2002, it has withstood the test of various on-site environments. Practice has proved that the system control accuracy is stable and the stability is complicated. In particular, the complicated function of controlling the risk factor is integrated into the software of the system, which makes the operation simple and easy to understand. It is well received by users and has better control of compressor anti-surge control. High promotion and application value.
The revised draft was received on the date of 20040416.
Professional; mainly engaged in the design and commissioning of automatic control systems.
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