CN101498934B - Coordination control method for integral coal gasification combined circulation power station - Google Patents

Abstract

The invention puts forward a coordinated control method for an integrated coal gasification combined cycle power plant, aiming at a characteristic that the time constant of each equipment of the controlled object in the integrated coal gasification combined cycle power plant has great difference. The method adopts a cascade stratified control system structure, and is provided with an upper-layered main controller, namely, a coordination controller, and a lower-layered sub controller, namely, comprising a gasification island sub controller and a power island sub controller, wherein, the main controller is used for the calculation of a main control command and then sends to the lower-layered sub controller for the control of corresponding equipments, the lower-layered sub controller is also in charge of the regulation of other main controlled variables in the system; the control method coordinates the running of each equipment of the power plant gasification island and the power island, and realizes power plant load automatic regulation by the premise of guaranteeing the stability and safety of the power plant; and by applying the method, a coordinated control system provided with good stability and variable load performance can be conveniently designed according to different types of integrated coal gasification combined cycle units.

Description

The control method for coordinating of integral coal gasification combined circulation power station

Technical field

The invention belongs to the device control technical field, particularly a kind of control method for coordinating of integral coal gasification combined circulation power station.

Background technology

The integrated gasification combined cycle for power generation technology is a kind of new-generation technology that combines Coal Gasification Technology and gas-steam combined circulating technology, because the special pollutant removing process of its coal gasification stage design and gas-steam combined cycle system are to the cascade utilization characteristic of energy, therefore with respect to conventional thermal power generation unit, integrated gasification combined cycle for power generation has the advantage that pollutant emission is few and generating efficiency is high, it is clean coal power generation technology with wide application prospect, its The Research of Relevant Technology has been become focus both at home and abroad at present, China has listed the IGCC Study on Technology in national high-tech research development plan (863 Program), finishes a plurality of demonstration projects during 11th Five-Year.

The integrated gasification combined cycle for power generation technology combines Coal Gasification Technology and gas-steam combined circulating technology, therefore to relate to number of devices numerous in whole power station, many equipment relate to multiple very complex physicochemical process again, it is also very big that time constant differs, and the many equipment in the Great War at present, gasified boiler system particularly, its theoretical research and engineering are used all immature.From development trend; the same with conventional thermal power generation unit, the IGCC power station also needs to bear the peak load regulation network task, rather than bears basic load; this just requires the IGCC power station the same with conventional coal fired power plant, can carry out load responding fast under the condition that guarantees the set steady operation.In the IGCC power station, gasification island and these two subsystems that time constant difference is huge of Power island have been comprised, caused very big difficulty for the design of control system, IGCC power station coordinated control system reasonable in design, the assurance system is load responding speed and keep system stability faster, and is significant for the wide popularization and application in the IGCC power station of clean and effective.The research to the coordinated control system of integral coal gasification combined circulation power station at present both at home and abroad not have report substantially, does not form more that detailed control method is introduced in detail and detailed implementation step such as controller parameter adjusting.

Summary of the invention

Technical matters: the deficiency that the present invention is directed to existing integral coal gasification combined circulation power station control technology, a kind of control method for coordinating of integral coal gasification combined circulation power station is proposed, guaranteeing under the stable condition in power station, realize the fast automatic adjusting of load, this method is provided with master controller and sub-controller, clear and the closing to reality of control function logical partitioning can carry out engineering construction easily on existing control system hardware and software platform.

Technical scheme: various and each equipment time constant differs huge characteristics to this method at integral coal gasification combined circulation power station equipment, by foundation and time constant analysis to the main plant model in power station, set up a kind of control method for coordinating pointedly, this method adopts step hierarchy system structure, the master controller that is provided with the upper strata is that the sub-controller of tuning controller and lower floor promptly comprises gasification island controller and Power island sub-controller, carried out the computing of master control instruction and passed to the control that lower floor's sub-controller carries out relevant device by master controller, lower floor's sub-controller also is responsible for the adjusting of other main controlled variables separately in the system; The operation of this gasification island, control method coordination power station and each equipment of Power island is guaranteeing to realize load adjusting automatically in power station under stable with the safe prerequisite in power station; The whole process of this method is divided into controller architecture design and controller parameter with following feature and adjusts two stages:

In the controller architecture design process, at first each major equipment of power station is determined controlled volume and manipulated variable, then each input channel of individual equipment is carried out upset test under the steady working condition, each device model of match, and definite each equipment time constant, according to device model, the control system of design subsystem; Finish the sub-controller of gasification island and Power island in design after, coordinate controlling schemes according to two kinds of master controllers, select corresponding manipulated variable and controlled variable pair relationhip, the coordinated control system on design upper strata, receive real power, power station gas pressure feedback and the current power station equipment status signal sent out of external load instruction and unit, carry out gas pressure and set, through the computing of master controller, output order is coordinated the operation of gasification island and Power island to the sub-controller of lower floor;

In control method for coordinating parameter adjustment process, at first according to the mathematical model (particularly its time constant) of gasification island and Power island and the control structure of sub-controller separately, carry out the adjustment of controller parameter according to the engineering setting method, then each control loop is dropped into operation with closed ring one by one, carry out setting value step disturbance test, again regulator parameter is carried out fine tuning; After gasify island and the parameter adjustment of Power island sub-controller are finished, carrying out master controller is the adjusting of tuning controller parameter, the sub-controller input is automatic, use the engineering method of adjusting load and pressure master selector parameter and main control loop in the adjusting of feedforward controller parameter, after master controller is also dropped into automatically, carry out the parameter fine tuning by the step disturbance experiment, finally finish the adjusting of total system control system parameter.

Two kinds of different coordination controlling schemes of described master controller are specially:

1. adopt the gasification island to carry out power station gas pressure P _GASAdjusting, and adopt Power island to carry out power station load N _EAdjusting, carry out Load Regulation fast, and in pressure is regulated, add the unit load command N ₀Ratio add the differential feed-forward signal, with the rapidity that guarantees that gas pressure is regulated, this method is called with the gasification island follows control method for coordinating into the basis;

2. adopt the gasification island to carry out power station load N _EAdjusting, and adopt Power island to carry out power station gas pressure P _GASAdjusting, carry out gas pressure fast and regulate, and in the Load Regulation of power station, add the load command N ₀Ratio add differential feed-forward signal and power station gas pressure P _GASRatio add the differential feed-forward signal, to guarantee the rapidity of Load Regulation.This method is called with Power island follows control method for coordinating into the basis;

Two kinds of methods of this that adopts in the master controller can only have a kind of input automatic at synchronization, can carry out unperturbed as required switches, to satisfy the coordination control requirement under the different ruuning situations, simultaneously since the output of manual mode from the output of motion tracking automated manner, so the handoff procedure of dual mode is a unperturbed.

The basic controlling algorithm that master controller and sub-controller adopted is the dispersion PID control method, adopt the single loop control algolithm in conjunction with feedforward control, understood and grasps by operation and technician easily, and enforcement on existing control system hardware and software platform, modification and maintenance easily.

Beneficial effect: adopt the control method for coordinating of disclosed integral coal gasification combined circulation power station among the present invention that control is coordinated in the power station, have following useful effect:

(1) controller structure design and the parameter tuning that carries out according to plant characteristic, can coordinate the equipment operation of different time constant, under the prerequisite that guarantees system stability and device security, make the real power of sending out in power station follow the tracks of the external load instruction fast, make system operation more steadily, economy and safety, because the raising of power station automation degree can also effectively alleviate operations staff's manipulation strength;

(2) The whole control system is no matter be master controller or each sub-controller, all adopt conventional proportion integration differentiation control law, in addition necessary feedforward regulator etc., power station operations staff and technician understand easily and accept, and can implement on existing control system hardware and software platform easily, revise and safeguard.Simultaneously, because proportion integration differentiation control is the bottom and the reserved regimen of various Advanced Control strategy step control structures, the enforcement of the control method for coordinating that the present invention proposes can make things convenient for following Advanced Control implementation of strategies.

Description of drawings

Fig. 1 is the coordinated control system one-piece construction figure of integral coal gasification combined circulation power station.

Fig. 2 is a gasification island controller control strategy synoptic diagram.

Fig. 3 is a Power island sub-controller control strategy synoptic diagram.

Fig. 4 follows control method synoptic diagram into the basis with the gasification island in the master controller.

Fig. 5 follows control method synoptic diagram into the basis with Power island in the master controller.

Fig. 6 is the curve of output that among the embodiment certain integral coal gasification combined circulation power station is carried out the controlled volume of load change test.

Fig. 7 is the manipulated variable change curve that among the embodiment certain integral coal gasification combined circulation power station is carried out load change test.

Embodiment

This method is at the different qualities of gasification island in the integral coal gasification combined circulation power station controlled device and Power island equipment, designs a kind of control method for coordinating that can effective coordination different time constant equipment operation.This method comprises two kinds of control strategies: a kind of is to adopt the gasification island that the power station gas pressure is regulated, to keep-up pressure and whole power station stable, and adopt Power island that the real power of sending out in power station is regulated, guaranteeing that unit is real sends out the control method that power can be followed the tracks of the variation of external load instruction fast, is called with the gasification island to follow control method for coordinating into the basis; Another kind is to adopt Power island that the power station gas pressure is regulated, to keep-up pressure and whole power station stable, and adopt the gasification island that the real power of sending out in power station is regulated, guarantee the control method that the real power of unit is followed the tracks of the variation of external load instruction fast, be called with Power island and follow control method for coordinating into the basis, these two kinds of methods can be carried out unperturbed as required and be switched.Control method for coordinating proposed by the invention can guarantee the power plant safety economical operation, and reduces operations staff's labour intensity, and simultaneously, this method can be implemented easily.

This control method for coordinating mainly is divided into following two stages:

1. in the control method for coordinating design process, at first each major equipment of power station is determined controlled volume and manipulated variable, then each input channel of individual equipment is carried out upset test under the steady working condition, each device model of match, and determine each equipment time constant, and according to device model, the control system of design subsystem, implement and debugging for convenient, the general employing disperseed proportion integration differentiation control.After the sub-controller design of gasification island and Power island is finished, the coordinated control system on upper strata be can design, external load instruction and current power station equipment status signal received, carrying out gas pressure sets, through computing, output order is coordinated the operation of gasification island and Power island to the sub-controller of lower floor.

2. in control method for coordinating parameter adjustment process, at first according to the mathematical model (particularly its time constant) of gasification island and Power island and the control structure of sub-controller separately, carry out the adjustment of controller parameter according to the engineering setting method, then each control loop is dropped into operation with closed ring one by one, carry out setting value step disturbance test, again regulator parameter is carried out fine tuning.After gasify island and the parameter adjustment of Power island sub-controller are finished, carry out the adjusting of master controller (tuning controller) parameter, the sub-controller input is automatic, use the engineering method of adjusting load and pressure master selector parameter and main control loop in the feedforward controller parameter adjust, after master controller is also dropped into automatically, carry out the parameter fine tuning by the step disturbance experiment, finally finish the adjusting of total system control system parameter.

The control method for coordinating of integral coal gasification combined circulation power station, adopt the method for master controller and gasification island and Power island sub-controller layering combination that whole power station is controlled automatically, on the basis that guarantees the power station equipment safety and stability, realize the quick tracking of load, effectively alleviate operations staff's manipulation strength.The one-piece construction of control method for coordinating proposed by the invention and integral coal gasification combined circulation power station major equipment and schematic flow sheet are as shown in Figure 1.Can be clear that from figure whole power station equipment can be divided into gasification island and Power island two parts, the island of wherein gasifying mainly comprises gasified boiler system, air separation unit (only at oxygen gasified technology) and gas purification dust arrester etc.; Power island is conventional gas-steam combined cycle system, comprises that mainly gas turbine is equipment such as its auxiliary generator, waste heat boiler, steam turbine and auxiliary generator thereof.The present invention says that the controller that the control method for coordinating of proposition relates to is divided into two levels, be the master controller (being also referred to as tuning controller) on upper strata and the sub-controller of lower floor, master controller receives the load scheduling instruction, the gas pressure setting value, signals such as gas pressure feedback and the real Feedback of Power of unit, instruct by certain algorithm computation go out the to gasify feed instruction on island and pitch aperture of Power island gas turbine according to the unit current operating state, send into each sub-controller of lower floor respectively, the instruction that each sub-controller will receive after treatment, sending into separately actuator controls corresponding device, simultaneously, sub-controller also needs to finish the adjusting task that each system comprises the controlled variable of equipment own, as the calorific value of gas on the island of gasifying, controls such as gasifier temperature, the combustion turbine exhaustion temperature control of Power island etc.

The control method that the present invention proposes mainly is divided into two aspects: the one, according to the controller architecture design of device characteristics, guarantee the rationality and the validity of control method; The 2nd, according to the controller parameter adjustment of equipment actual motion characteristic, to guarantee each equipment operation stationarity and capability of fast response to loading.Below in conjunction with drawings and Examples technical scheme of the present invention is further described.

Embodiment: certain integrated gasification combined cycle plants demonstration power station, adopt air gasification airflow bed gasification furnace and the supporting combustion and steam combined cycle system thereof of rated load 87MW, the main regulated variable of gasification furnace comprises: the outlet calorific value of gas, gas pressure, gasifier temperature and gasification siege material amount, main manipulated variable comprises: the gasification furnace coal-supplying amount, gasification furnace is gone into hearthstone lime stone amount, the gasification furnace air capacity, gasification furnace bed drain purge and gasification furnace steam in the boiler amount etc., the main disturbance of system changes caused gas pressure change for going into variation of stove coal ature of coal and downstream gas consumption, and gasification island structure synoptic diagram as shown in Figure 2.The combustion and steam combined cycle adopts the waste heat boiler and the supporting steam turbine thereof of heavy single-rotor gas turbine and no afterburning.Gas turbine adopts speed/load control, Acceleration Control and temperature control to get little fuel control method, for guaranteeing to enter the exhaust-heat boiler flue gas temperature, adopt the adjustable inlets stator to carry out the combustion turbine exhaustion adjustment, the Power island structural representation as shown in Figure 3.

In the controller architecture design phase, at first system has been carried out modeling, detailed process is as follows:

Adopt system identifying method to carry out modeling at gasification furnace, its discrete state spatial model on 100% and 50% operating point is:

Benchmark model on 100% operating point:

$+{\left[\begin{array}{ccccccccccccccccc}-0.0332& 0.0823& -0.2424& 0.2072& 1.0035& -0.9379& 0.4184& 2.0407& -1.2374& 0.0399& 0.4441& -0.0902& 0.3946& -1.5826& -0.5599& -0.2949& -0.5952\\ 3.4350& -25.9189& -18.2965& -12.0686& 0.1616& -0.1697& -6.7244& 2.4918& -0.2656& 10.4720& 19.6778& 49.5628& -13.4826& -17.3111& 10.9783& -30.0931& 51.6431\\ -7.8024& 43.9223& -26.1315& -43.4061& 0.1289& 0.5012& 20.4221& -7.4143& 1.9282& -0.6306& 57.3698& -3.7266& 34.4123& 21.3713& 31.9043& -35.3804& -3.3630\\ 0.6550& 10.9902& -2.9788& -6.8633& 0.0824& 0.2111& 16.2341& -5.3258& 0.0050& -1.6094& -31.8406& 72.9178& 41.7376& -3.0376& 41.9678& 10.5753& -50.6257\end{array}\right]}^{T}u\left(k\right)$

$y\left(k\right)=\left[\begin{array}{ccccccccccccccccc}-8.6584& 46.4082& -9.6769& -25.4387& 0.3073& 0.2275& 17.5463& -5.7490& 0.0030& 30.1116& 30.9688& -148.5792& 11.7673& 13.7873& 12.2755& 31.1294& -13.4318\\ -0.0001& 0.0641& -0.0257& -0.0207& 0.0014& 0.0222& -0.0109& -0.0814& -0.1047& -0.0025& -0.0274& 0.0244& 0.1103& -0.0237& -0.1096& 0.0680& 0.0916\\ 0.5209& -1.1595& 3.1698& 3.8933& -0.0995& 0.0803& -6.9083& 1.6385& -0.2156& 0.8435& 15.7549& 58.2087& -1.4444& -60.3379& 84.0803& -10.9552& 91.4374\\ 0.0006& -0.0053& 0.0011& 0.0029& -0.0000& -0.0000& -0.0038& 0.0012& -0.0000& 0.0006& 0.0071& -0.0023& -0.0099& -0.0385& 0.0443& 0.0078& 0.0573\end{array}\right]x\left(k\right)+\left[\begin{array}{cccc}0& 0& 0& 0\\ 0& 0& 0& 0\\ 0& 0& 0& 0\\ 0& 0& 0& 0\end{array}\right]u\left(k\right)$

Benchmark model on 50% operating point:

$+{\left[\begin{array}{ccccccccccccccccc}0.1218& -0.2647& 0.1711& 0.7596& 0.9205& -1.0402& 1.9488& -0.2770& -1.3075& -0.0565& 0.0982& -0.0091& -0.9344& -1.2374& 1.0881& -0.2189& 0.0319\\ -14.7094& -40.3307& -33.0915& 0.4210& 0.0976& -0.1665& 1.4139& 7.8519& -2.8201& -31.9888& 10.2214& -0.9361& -12.1926& 17.4166& 18.4455& 65.7868& -96.8185\\ 33.4807& 36.9209& 18.3269& -0.1627& -0.2979& 0.3436& -0.8636& 45.5201& -13.2953& 47.4635& 42.6472& -3.8746& 0.5644& -16.2725& -23.3534& 11.6735& -46.7419\\ 11.1824& 28.7342& 23.6864& -0.2606& -0.0167& 0.0352& -0.0768& -8.7514& 2.8931& 24.4970& -10.6454& 0.9563& -11.3078& 52.6411& 45.2511& -59.7693& -47.9776\end{array}\right]}^{T}u\left(k\right)$

$y\left(k\right)=\left[\begin{array}{ccccccccccccccccc}24.5623& 12.5730& -1.0973& 0.3523& 0.0051& -0.0201& -0.0766& 57.1882& -19.1450& 47.6680& 30.4309& -2.7613& 23.0892& -80.8475& -82.3572& 1.6939& 74.4993\\ 0.0492& -0.0176& -0.0181& 0.0174& -0.0085& 0.0286& -0.0833& 0.0174& -0.1172& -0.0137& 0.0347& -0.0032& -0.1559& 0.0842& -0.0120& 0.0179& 0.0634\\ -2.5052& -42.0872& -41.2445& 0.6282& -0.0636& 0.1398& -0.4638& 34.3901& -11.6677& -39.9241& 27.6286& -2.4988& 1.1518& 12.2709& -3.5051& -35.1437& -76.4813\\ -0.0060& -0.0395& -0.0368& 0.0005& 0.0000& -0.0000& 0.0000& 0.0247& -0.0082& -0.0345& 0.0211& -0.0019& 0.0069& -0.0078& -0.0175& -0.0219& -0.0277\end{array}\right]x\left(k\right)+\left[\begin{array}{cccc}0& 0& 0& 0\\ 0& 0& 0& 0\\ 0& 0& 0& 0\\ 0& 0& 0& 0\end{array}\right]u\left(k\right)$

This is the multi-variable system of one four input four outputs, and that is adopted is input as: bed drain purge, coal-supplying amount, air capacity and quantity of steam, and be output as calorific value of gas, gas pressure, bed material amount and gasifier temperature.Gasification island controller for reasonable in design carries out the relative gain matrix analysis to system, and the calculating of relative gain matrix Λ can be carried out according to following short-cut method:

Λ＝K·(K ^-1) ^T

Wherein K represents system's open-loop gain matrix, can obtain the multiplying each other of representing matrix corresponding element, i.e. the Hadamard product of matrix by the step disturbance under steady working condition test easily.

Under 100% operating mode, to system four inputs do respectively 10% the instruction step increase test, by the system responses tracing analysis, can obtain system's open-loop gain matrix K

$K=\left[\begin{array}{cccc}14328& -46238& 22239& -54097\\ -5743.9& -1388.4& 4692& -692.55\\ -671.8& 13664& 1406.3& 7562.9\\ -2.283& 20.695& -18.503& -44.8476\end{array}\right]$

Utilize following formula, the RGA that can calculate system under 100% operating mode is as shown in table 1:

Relative gain matrix analysis under table 1100% operating mode

According to the result of relative gain matrix analysis, can obtain the collocation relation between required manipulated variable and the controlled variable, that is:

(1) calorific value of gas is regulated by the gasification furnace coal-supplying amount, and the change of coal amount influences the composition of product combustible, thereby influences the enthalpy of coal gas;

(2) the bed material is regulated by bed drain purge, and the variable effect of bed drain purge is to total material balance;

(3) gas pressure is regulated by air capacity, and the variation of air capacity can change gas pressure fast;

(4) gasifier temperature is regulated by quantity of steam, and the variation of quantity of steam can change the temperature of gasified boiler system fast.

According to above pair relationhip, can tentatively determine gasification island controller architecture, adopt the control of single loop proportion integration differentiation at each passage, be convenient to implement and parameter adjustment.

For Power island; topmost equipment is gas turbine; gas turbine model and basic control system are as shown in Figure 3; for the gasification island; by finding to the gas turbine modeling; its model time constant very little (generally all in 10 seconds); its sub-controller structure is basic fixed also; classical load/rotating speed control is adopted in the adjusting of fuel quantity; temperature control and Acceleration Control are got little mode production control instruction; the adjustable inlets stator is set to be controlled exhaust; it should be noted that the fuel quantity instruction has the lower bound protection in order to keep the no-load running under the zero load, promptly fuel quantity is minimum is 0.23 (numerical value after the normalization).

Design for the master controller design, take into account the stability of gas pressure simultaneously for the quick response that guarantees load, and the coordinated control system that satisfies under the different service conditions drops into requirement, the present invention has designed two kinds in master controller can carry out the control method for coordinating that unperturbed switches as required: a kind of being called with the gasification island, followed control method for coordinating into the basis, corresponding master controller structural representation as shown in Figure 4, adopt the gasification island that gas pressure is controlled, adopt Power island that plant generator power is controlled; Another kind is called with Power island follows control method for coordinating into the basis, and corresponding master controller structural representation adopts Power island that gas pressure is controlled as shown in Figure 5, adopts the gasification island that plant generator power is controlled.

The main input quantity of master controller is external load dispatch command, gas pressure feedback, real Feedback of Power and the current power station equipment status signal sent out in power station, be output as instruction of gasification island and Power island instruction, send into respectively in the corresponding lower floor sub-controller, specifically send operational order by sub-controller again, coordinate the operation of each internal system equipment, load to external world to instruct with assurance system stable operation and the real power of change and make quick response.The power of master controller and pressure setting can be adopted automatic setting (transferring the function of instruction power of the assembling unit instruction after treatment in the electrical network) or manually be set by the operations staff as required.Because Power island is a fast process, therefore adopted the integro-differential single loop control of simple proportional; And the gasification island is a slow process, adopt simple single loop proportion integration differentiation control to be difficult to obtain gratifying control effect, therefore designed the controlling schemes that feedback as shown in Figure 4 combines with feedforward, wherein feed-forward regulation (ratio adds actual differential regulator) plays a leading role, can carry out quick adjustment according to the variation of load instruction, feedback regulation (proportional integral derivative controller) helps out, and can guarantee that system does not have static difference under the stable situation.So far, the structural design of the coordinated control system master controller of integral coal gasification combined circulation power station and sub-controller finishes.

In the controller parameter adjustment process, need to obtain system model equally, carry out regulator parameter setting and adjustment according to system model then, the most at last each loop drop into the fine tuning of carrying out parameter automatically until the coordination control with the superiors drop into operation automatically (the following design process control method for coordinating of following based on gasification furnace is an example, the power stove follow into the control method for coordinating design process on basis and this method similar).

At gasification furnace control structure as shown in Figure 2, regulate in order to carry out controller parameter, corresponding passage has been carried out Model Distinguish, obtain four following transfer function models:

The transport function that is obtained by response curve is as follows:

Air capacity is to gas pressure: $W_{P-A}\left(s\right)=\frac{0.04}{{(200s+1)}^2(2000s+1)}$

Bed drain purge is to bed material amount: $W_{M-\mathrm{Ch}}\left(s\right)=\frac{-6.5}{(s+1)(150s+1)(2500s+1)}$

Quantity of steam is to gasifier temperature:

$W_{T-\mathrm{Stm}}\left(s\right)=\frac{-0.05}{{(s+1)}^2(5000s+1)}+\frac{0.09}{{(s+1)}^2(1200s+1)}+0.1$

Coal-supplying amount is to calorific value of gas: $W_{\mathrm{CV}-\mathrm{Col}}\left(s\right)=\frac{-0.35}{(s+1)(150s+1)(2500s+1)}$

$+\frac{0.2}{(s+1)(150s+1)(2500s+1)}{e}^{-2500s}+0.1$

According to above transfer function model time constant, and, determine that controller parameter is as shown in table 2, it should be noted that the gas pressure regulator of master controller also need tentatively be adjusted in this stage through online adjustment:

The regulator parameter on table 2 gasification island

For Power island, mainly need carry out the adjusting of gas turbine engine systems regulator parameter, the transport function of gas turbine key link is:

The fuel valve steady arm: $W_{\mathrm{VP}}\left(s\right)=\frac{1}{1+0.2s};$

Fuel system: $W_{\mathrm{FS}}\left(s\right)=\frac{1}{1+0.4s};$

The gas turbine characteristic: $W_{\mathrm{GT}}\left(s\right)=\frac{1.3}{1+0.4s}\×(W_f-0.23)+0.5\×(1-\mathrm{\Ω}),$ W wherein _fBe fuel quantity, Ω is a gas turbine rotary speed;

Characteristic is covered in heat radiation: $W_{\mathrm{RS}}\left(s\right)=0.8+\frac{1}{1+5s};$

Thermocouple characteristic: $W_{\mathrm{CP}}\left(s\right)=\frac{1}{1+2.5s};$

The inlet guide vane characteristic: $W_{\mathrm{IGV}}\left(s\right)=\frac{1}{1+4s}$

As for waste heat boiler and supporting steam turbine, proportion is less in the total system generated energy, and operating condition is more stable relatively, and its model can be simplified, and the model of waste heat boiler can be represented with following formula:

${\stackrel{\·}{m}}_{\mathrm{steam}}=\frac{{\mathrm{\η}}_{\mathrm{HRSG}}\·{\stackrel{\·}{m}}_{\mathrm{exgas}}}{{\mathrm{\Δh}}_{\mathrm{steam}}}\·(c_p^{\mathrm{in}}\·T_{\mathrm{exgas}}^{\mathrm{in}}-c_p^{\mathrm{out}}\·T_{\mathrm{exgas}}^{\mathrm{out}})$

Wherein

Be steam or extraction flow;

Δ h _SteamFor steam enthalpy in the waste heat boiler increases;

η _HRSGBe waste heat boiler efficient;

c _p ^In, c _p ^OutThe specific heat at constant pressure of exhaust turnover waste heat boiler;

T _Exgas ^In, T _Exgas ^OutThe temperature of exhaust turnover waste heat boiler.

Utilize following formula can calculate the gas production rate of waste heat boiler, the characteristic of steam turbine is simplified with constant, is used for converting the quantity of steam of waste heat boiler to generated energy.Sub-controller at waste heat boiler and steam turbine also adopts independently conventional proportion integration differentiation control law, mainly vapor pressure is controlled.

According to above Power island model time constant, and, determine that controller parameter is as shown in table 3, it should be noted that the unit load regulator of master controller also need carry out preliminary adjustment in this stage through online adjustment:

The regulator parameter of table 3 Power island

In the master controller, the unit load regulator is that simple single loop proportional integral is a regulator, and parameter need be carried out online fine tuning in this stage, is about to drop into automatically, changes setting value observation response curve by step and adjusts; Gas pressure proportional integral derivative controller parameter is used with quadrat method and is adjusted, proportional action in the feedforward controller (ratio adds differential) can be determined by the static proportion relation of load increment and coal-supplying amount increment, the differential action is then determined by the size that overshoot is set, and is as shown in table 4 through the parameter of adjusting:

Table 4 master selector parameter (control method for coordinating of following based on the gasification island is an example)

So far, integral coal gasification combined circulation power station gasification island proposed by the invention is followed to the control method for coordinating on basis and is implemented to finish, and utilizes the method, and embodiment has been carried out two-way load change test, and the test findings that obtains as shown in Figure 5.Can see that from the result unit load is followed the tracks of very fast, and pressure surge is very little, each other controlled variable also fluctuates in the variation range that allows.

Claims (2)

1. the control method for coordinating of an integral coal gasification combined circulation power station, it is characterized in that this method adopts step hierarchy system structure, the master controller that is provided with the upper strata is that the sub-controller of tuning controller and lower floor promptly comprises gasification island controller and Power island sub-controller, carried out the computing of master control instruction and passed to the control that lower floor's sub-controller carries out relevant device by master controller, lower floor's sub-controller also is responsible for the adjusting of other main controlled variables separately in the system; The operation of this gasification island, control method coordination power station and each equipment of Power island is guaranteeing to realize load adjusting automatically in power station under stable with the safe prerequisite in power station; The whole process of this method is divided into controller architecture design and controller parameter with following feature and adjusts two stages:

In the controller architecture design process, at first each major equipment of power station is determined controlled volume and manipulated variable, then each input channel of each equipment is carried out upset test under the steady working condition, each device model of match, and definite each equipment time constant, according to device model, the control system of design subsystem; Finish the sub-controller of gasification island and Power island in design after, according to two kinds of master controller control method for coordinating, select corresponding manipulated variable and controlled variable pair relationhip, the coordinated control system on design upper strata, receive real power, power station gas pressure feedback and the current power station equipment status signal sent out of external load instruction and unit, carry out gas pressure and set, through the computing of master controller, output order is coordinated the operation of gasification island and Power island to the sub-controller of lower floor;

In the controller parameter adjustment process, at first according to the mathematical model of gasification island and Power island and the control structure of sub-controller separately, carry out the adjustment of controller parameter according to the engineering setting method, then each control loop is dropped into operation with closed ring one by one, carry out setting value step disturbance test, again regulator parameter is carried out fine tuning; After gasify island and the parameter adjustment of Power island sub-controller are finished, carrying out master controller is the adjusting of tuning controller parameter, the sub-controller input is automatic, use the engineering method of adjusting load and pressure master selector parameter and main control loop in the adjusting of feedforward controller parameter, after master controller is also dropped into automatically, carry out the parameter fine tuning by the step disturbance experiment, finally finish the adjusting of total system control system parameter;

Described two kinds of master controller control method for coordinating are specially:

1. follow control method for coordinating with the gasification island into the basis; Adopt the gasification island to carry out power station gas pressure P _GASAdjusting, and adopt Power island to carry out power station load N _EAdjusting, carry out Load Regulation fast, and in pressure is regulated, add the unit load command N ₀Ratio add the differential feed-forward signal, with the rapidity that guarantees that gas pressure is regulated,

2. follow control method for coordinating with Power island into the basis; Adopt the gasification island to carry out power station load N _EAdjusting, and adopt Power island to carry out power station gas pressure P _GASAdjusting, carry out gas pressure fast and regulate, and in the Load Regulation of power station, add the load command N ₀Ratio add differential feed-forward signal and power station gas pressure P _GASRatio add the differential feed-forward signal, to guarantee the rapidity of Load Regulation.

2. the control method for coordinating of a kind of integral coal gasification combined circulation power station according to claim 1, it is characterized in that the basic controlling algorithm that master controller and sub-controller adopt is the dispersion PID control method, adopt the single loop control algolithm in conjunction with feedforward control.

Images