Method of surge prevention pre-alarm of turbo compressor
Technical field
The present invention relates to a kind of method of surge prevention pre-alarm of turbo compressor, specifically, relate to the anti-surge pre-alarm method of the turbocompressor that has surge-proofing controller.
Background technique
As shown in Figure 1 and Figure 2, y coordinate is compressor delivery pressure P, and abscissa is flow Q.There is the upper limit in turbocompressor operation point in service---and surge line 1, promptly surge line 1 can not be crossed in operation point 4.If cross surge line 1, turbocompressor will produce surge, and the unit high vibration will thoroughly damage at short notice.
Cross surge line 1 in order to prevent turbocompressor when operation operation point 4, turbocompressor generally all attaches surge-proofing controller, its control principle is: the line 2 that leaks informaton is set below surge line 1, when line 2 is leaked informaton in 4 arrival of compressor operating point (operation point 4 meetings of compressor change along with the variation of the working condition of gas equipment), vent valve on the compressor outlet pipe is just opened certain amplitude, make compressor operating point 4 leave the line 2 that leaks informaton, thereby break away from the danger that enters surge line, guarantee the safety of compressor.
There is such shortcoming in this control principle of surge-proofing controller: owing to do not report to the police before arriving the line 2 that leaks informaton in operation point 4, so can not arriving the line 2 that leaks informaton in operation point 4, operator cause vent valve to be intervened in advance before opening, because vent valve moment opens fast, the tolerance and the air pressure of compressor output fluctuate widely, and influence the ordinary production of technological process.
Summary of the invention
The objective of the invention is to, a kind of method of surge prevention pre-alarm of turbo compressor is provided, to increase the stability and the reliability of turbocompressor operation, reduce the adverse effect of vent valve frequent movement, alleviate operator monitors compressor disturbances of power and the working pressure brought all the time the whole production flow process.
For reaching above-mentioned purpose, technological scheme of the present invention is as follows:
A kind of method of surge prevention pre-alarm of turbo compressor, described compressor has surge-proofing controller, the line that leaks informaton of function relation between default compressor delivery pressure value of this controller and the flow value.Be characterized in, comprise the steps: to set the alarming line of function relation between a compressor delivery pressure value and the flow value; Gather the outlet pressure value and the flow value of compressor operating point in real time; With comparing with the pairing outlet pressure value of the flow value of operation point on the outlet pressure value of operation point and the described line that leaks informaton, obtain a pressure difference absolute value; With comparing with the pairing outlet pressure value of operation point flow value on the alarming line He on the above-mentioned line that leaks informaton, obtain a standard pressure difference absolute value; Above-mentioned pressure difference absolute value and standard pressure difference absolute value are compared, if the pressure difference absolute value then triggers warning device less than standard pressure difference absolute value.
A kind of method of surge prevention pre-alarm of turbo compressor, described compressor has surge-proofing controller, the line that leaks informaton of function relation between default compressor delivery pressure value of this controller and the flow value.Be characterized in, comprise the steps: to set the alarming line of function relation between a compressor delivery pressure value and the flow value; Gather the flow value and the outlet pressure value of compressor operating point in real time; With comparing with the pairing flow value of outlet pressure value of operation point on the flow value of operation point and the described line that leaks informaton, obtain a difference in flow absolute value; With comparing with the operation point pairing flow value of outlet pressure value on the alarming line He on the above-mentioned line that leaks informaton, obtain a normal flow difference absolute value; Above-mentioned difference in flow absolute value and normal flow difference absolute value are compared, if the difference in flow absolute value then triggers warning device less than normal flow difference absolute value.
A kind of method of surge prevention pre-alarm of turbo compressor, described compressor has surge-proofing controller, the line that leaks informaton of function relation between default compressor delivery pressure value of this controller and the flow value.Be characterized in, comprise the steps: to set the alarming line of function relation between a compressor delivery pressure value and the flow value; Gather the flow value and the outlet pressure value of compressor operating point in real time; With comparing with the operation point pairing flow value of outlet pressure value on the flow value of operation point and the described line that leaks informaton, obtain a difference in flow absolute value; With comparing with the pairing outlet pressure value of operation point flow value on the outlet pressure value of operation point and the described line that leaks informaton, obtain an outlet pressure difference absolute value simultaneously; With comparing with the operation point pairing flow value of outlet pressure value on the alarming line He on the above-mentioned line that leaks informaton, obtain a normal flow difference absolute value; With comparing with the pairing outlet pressure value of operation point flow value on the alarming line He on the above-mentioned line that leaks informaton, obtain a standard outlet pressure difference absolute value simultaneously; Above-mentioned difference in flow absolute value and normal flow difference absolute value are compared, above-mentioned outlet pressure difference absolute value and standard outlet pressure difference absolute value are compared, if the difference in flow absolute value less than standard outlet pressure difference absolute value, then triggers warning device less than normal flow difference absolute value or outlet pressure difference absolute value.
By as above improving, before the operation point of compressor arrived the line that leaks informaton, the turbocompressor operation point at first arrived this alarming line, sent warning when arriving alarming line, so that operator in time adjust, thereby reduced the adverse effect of vent valve frequent movement to the whole production flow process.
Description of drawings
Fig. 1 is turbocompressor outlet pressure and flow function graph of a relation;
Fig. 2 is turbocompressor outlet pressure and flow function graph of a relation;
Fig. 3 is existing Anti-surge Control original program allocation plan;
Fig. 4 adds the overall arrangement figure of existing Anti-surge Control original program for method of surge prevention pre-alarm of turbo compressor of the present invention;
Fig. 5 is the flow chart of method of surge prevention pre-alarm of turbo compressor of the present invention.
Description of symbols among the figure
The 1-surge line
The 2-line that leaks informaton
The 3-alarming line
The 4-operation point
P-operation point outlet pressure value
P
*-line outlet pressure the value of leaking informaton
Q-operation point flow value
Q
*-the linear flow value leaks informaton
Xd-outlet pressure difference absolute value or difference in flow absolute value
B-standard outlet pressure difference absolute value or normal flow difference absolute value
Embodiment
In order to understand structure of the present invention, function and effect better, the following preferred embodiment of existing utilization is elaborated also in conjunction with the accompanying drawings.
The principle of the invention is, before the operation point 4 of compressor arrives the line 2 that leaks informaton, set an alarming value according to certain amplitude, forecast in advance, so that operator in time manually adjust vent valve aperture and compressor output tolerance (its adjustment process is: in the manual unlocking vent valve, increase compressor output tolerance, it is constant that the tolerance of gas equipment is sent in maintenance), the tolerance that compressor operating point 4 is left leak informaton line 2 and keep being sent to gas equipment remains unchanged, and avoids production is impacted.This alarming value can be set like this: the operation point 4 of compressor and the distance of the line 2 that leaks informaton are referred to as " outlet pressure difference absolute value or difference in flow absolute value " Xd (as depicted in figs. 1 and 2), as long as the some numerical value (for example b among Fig. 1 and Fig. 2) of getting Xd is as alarm setting value, is example with Xd<3% as alarming value, promptly leak informaton the distance of line 2 less than 3% the time when compressor operating point 4 distance, warning device just sends alarm signal.Line 2 is curves because leak informaton, apart from the line b place of leaking informaton have a few and also constituted an other line, be alarming line 3.
In the Anti-surge Control software of this axial flow compressor, Xd is defined as Xd=Q
*-Q (Q
*, Q implication as shown in Figure 2).So, when the operation point when the line that leaks informaton is following, Xd is a negative.It is-0.03 that this example is got the b value, and promptly when Xd>-0.03, control software sends alarm signal, informs that operator's compressor operating point 4 is about near leaking informaton line 2, and the prompting operator in time adjust.Specific implementation method is on the blast furnace axial flow compressor: revise the former anti-surge control of compressor software, utilize former alarming hardware device.The control program of revising is gathered Xd as shown in Figure 4 in real time; Xd is compared by comparator and standard deviation absolute value b, if the Xd absolute value less than normal flow difference absolute value b, then low side output 0, by the delayer time-delay after 1 second, input and door.Follow-up flow process is identical with existing method, no longer narration.
Consult Fig. 3, the program before revising is: 9121L1: the system alarm signal, and normal duration is 0, unusual duration is 1; GAI: amplifier, be input as XI, be output as Y, gaining is K, then: Y=K ∑ XI; PUS: will import " position " signal combination is " word " (16); CMP: comparator, be input as X1, X2, be output as Y, then when X1 〉=X2, when Y=1, X1<X2, Y=0; SEN: 80486 layers signals are sent to DSPU (digital signal processing unit) layer; RCV: from 80486 layers of acknowledge(ment) signal; SEL: from " word " signal, select " position " signal; DOT: digital signal outputs to hardware.
Fig. 5 is a control flow chart, comprises the steps: beginning; Gather compressor delivery pressure P, compressor outlet pressure reduction, compressor inlet temperature and inlet pressure; Inlet differential pressure, inlet temperature and inlet pressure calculating by compressor obtain compressor flowrate Q; Obtain the operation point of compressor by P and Q, the line that leaks informaton of this operation point and Anti-surge Control software set is compared, Xd must deviate; Is Xd greater than-0.03? if not, then return the beginning step; If, then output to hardware, send warning.
By above-mentioned principle explanation as can be known, in concrete enforcement, Xd also may be defined as Xd=Q-Q
*, Xd=P-P
*, Xd=P
*-P etc.; In the software programming, also can " comparator " module be set to when Xd reaches setting value, be output as 1; When Xd reaches setting value, can delayed alarm, can not delay time yet; Setting value b can rationally determine according to the Xd numerical value of concrete Anti-surge Control software.In a word, need only actual conditions, utilize above-mentioned principle, just can finish the enforcement of this pre-alarm device in conjunction with specific Anti-surge Control software.