1. A three-impulse frequency conversion automatic regulation method is characterized in that: comprises the following steps

A condensation pump outlet main pipe pressure variable frequency regulation control loop is eliminated, namely a condensation pump regulation PID control loop which sends a regulation instruction to a condensation pump variable frequency controller in a unit DCS control system is eliminated;

adding a three-impulse variable-frequency regulation control loop, introducing three impulses of the water level, the water supply flow and the condensate flow of a deaerator into a cascade regulation controller, correcting the water level deviation by using a regulator, ensuring that the water level has no static deviation, generating a set value of the main condensate flow by an output signal of a main regulator and a feed water flow feedforward signal through the action of the main regulator, applying the deviation of the set value and the actual main condensate flow to an auxiliary regulator, outputting the set value through the auxiliary regulator, and controlling a frequency output signal of variable-frequency regulation of a condensate pump, the rotating speed of the condensate pump is changed through the frequency change, the condensate flow is further changed, the water level regulation of the deaerator is controlled, the main regulator adopts load proportion control to ensure the stable regulation of the main regulation loop, the auxiliary regulator adopts load proportion control, so that the auxiliary loop can be adjusted quickly, and the three-impulse signal acts on the high-voltage frequency converter of the condensation pump, so that the frequency conversion controller of the condensation pump can directly and automatically adjust the water level of the deaerator; three impulse signals of deaerator water level, water supply flow and condensate flow act on a condensate pump high-voltage frequency converter under the condition of deep peak shaving of the thermal generator set, so that deaerator water level automatic adjustment is achieved by changing the rotating speed of a condensate pump, and throttling loss of a deaerator water level adjusting valve is reduced.

2. The three-impulse frequency conversion automatic regulating method according to claim 1, characterized in that: under the frequency conversion operation mode of the condensate pump, a three-impulse regulating logic loop of the deaerator water level regulating valve is cut off, and the deaerator water level regulating valve is fully opened, so that throttling loss is reduced to the maximum extent.

3. The three-impulse frequency conversion automatic regulating method according to claim 1, characterized in that: and when the frequency conversion device of the condensate pump fails, the condensate pump is automatically switched to a three-impulse-quantity adjusting logic loop of the deaerator water level adjusting valve in a power frequency operation mode.

4. The three-impulse frequency conversion automatic regulating method according to claim 1, characterized in that: the frequency conversion regulation control of the outlet pressure of the condensate pump is cancelled, the outlet pressure of the condensate pump is increased and reduced to 1.5MPa, the limitation of locking and reducing the frequency of a motor of the condensate pump is reduced, and the constant value of the low-pressure interlocked starting standby pump of the outlet pressure of the condensate pump is changed from 1.8MPa to 1.3 MPa.

5. The three-impulse frequency conversion automatic regulation method according to claim 4, characterized in that: increase the restriction that condensate pump outlet pressure is low to 1.5MPa shutting and subtracts condensate pump motor frequency, when arbitrary one of two condensate pumps is in frequency conversion state, when the oxygen-eliminating device water level control is the frequency conversion regulatory function, restriction oxygen-eliminating device water level frequency conversion regulatory frequency further reduces the function when condensate pump outlet pressure reduces to 1.5MPa, cut the condensate pump frequency conversion controller into manual regulation state and keep the present valve position of oxygen-eliminating device water level main regulating valve unchangeable by automatic status simultaneously, prevent that condensate pump outlet pressure from crossing unsatisfied condensate water supply demand excessively.

Background

At present, two sets of automatic regulating systems which coexist are generally arranged in a condensate system of a thermal generator set in China, one set is an automatic water level regulating system of a deaerator, and the water level of the deaerator is controlled within a specified range by regulating the flow of condensate water by controlling the opening of a water level regulating valve of the deaerator. The deaerator water level regulating valve adopts three impulse regulation of deaerator water level, boiler feed water flow and condensate flow. The other set is a frequency conversion automatic regulating system of the condensation pump, which takes the pressure of the condensation water mother pipe as a regulating object and controls the pressure of the condensation water mother pipe to be a set value by automatically regulating the frequency of a frequency converter (or changing the rotating speed of a motor of the condensation pump). In the normal operation process of the unit, the two sets of automatic regulating systems are simultaneously put into use.

In the electric power shortage period, the load factor of the unit is high, the output is generally more than 90% of the rated load or even the full load operation, the flow of condensed water is large under the working condition, the opening degree of the deaerator water level regulating valve is basically more than 90%, throttling loss hardly exists, and the operation mode is economical.

Along with the serious surplus of the capacity caused by the large increase of the total installed capacity of the thermal power generating units in China in recent years, the load rate of the units is greatly reduced, most of the thermal power generating units run under the working condition of low load for a long time, and the load rate of the units of part of the power plants is less than 50% of rated load on average. Meanwhile, in order to improve an energy structure and reduce environmental pollution, the installed capacity proportion of new energy such as wind power, photoelectricity and the like is gradually increased, in order to reduce the abandoned wind and abandoned light rate as much as possible, a thermal power generating unit participates in new energy consumption and carries out deep peak regulation, the load rate of the thermal power generating unit is changed to operate in a working condition within a 30-100% rated load range during the deep peak regulation, the change range of the condensate flow of a condensate system is large when the deep peak regulation of the thermal power generating unit is carried out, when the unit load is smaller than 90% of the rated load or even lower load participates in the peak regulation, the opening degree of a water level regulating valve of a deaerator is basically between 35% and 90%, the smaller the unit load is, the smaller the opening degree is, and the larger the throttling loss is. Although the frequency-conversion automatic regulating system of the condensate pump also participates in regulation, the problem of large throttling loss of the deaerator water level regulating valve cannot be solved by a regulating mode taking the pressure of a condensate header as a regulating object, and the maximum potential of frequency-conversion regulation and energy conservation of the condensate pump is not exerted.

In order to solve the problem of automatic throttling loss adjustment of the water level of the deaerator of the condensate system under the condition of low load or deep peak regulation of the unit of the thermal power plant, ideal energy-saving adjustment is as follows: when the unit is in low load or deep peak shaving, the opening degree of a deaerator water level regulating valve is kept to be larger or even fully opened as much as possible, a variable-frequency automatic regulating system of a condensation pump plays a leading regulating role, and the frequency of the frequency converter is reduced as much as possible to achieve the purpose of saving electricity under the condition that the pressure and flow requirements of deaerator water level automatic regulation and condensed water users (according to the process flow, condensed water not only supplies water to the deaerator, but also serves as cooling water, temperature reduction water and sealing water) are met.

Disclosure of Invention

The invention aims to provide a brand-new method for automatically adjusting the water level of a deaerator of a condensed water system under the condition of low load or deep peak shaving of a thermal generator set, so as to reduce throttling loss and achieve the aim of saving energy to the maximum extent.

The invention is realized by the following technical scheme:

a three-impulse frequency conversion automatic regulation method comprises the following steps

A condensation pump outlet main pipe pressure variable frequency regulation control loop is eliminated, namely a condensation pump regulation PID control loop which sends a regulation instruction to a condensation pump variable frequency controller in a unit DCS control system is eliminated;

adding a three-impulse variable-frequency regulation control loop, introducing three impulses of the water level, the water supply flow and the condensate flow of a deaerator into a cascade regulation controller, correcting the water level deviation by using a regulator, ensuring that the water level has no static deviation, generating a set value of the main condensate flow by an output signal of a main regulator and a feed water flow feedforward signal through the action of the main regulator, applying the deviation of the set value and the actual main condensate flow to an auxiliary regulator, outputting the set value through the auxiliary regulator, and controlling a frequency output signal of variable-frequency regulation of a condensate pump, the rotating speed of the condensate pump is changed through the frequency change, the condensate flow is further changed, the water level regulation of the deaerator is controlled, the main regulator adopts load proportion control to ensure the stable regulation of the main regulation loop, the auxiliary regulator adopts load proportion control, so that the auxiliary loop can be adjusted quickly, and the three-impulse signal acts on the high-voltage frequency converter of the condensation pump, so that the frequency conversion controller of the condensation pump can directly and automatically adjust the water level of the deaerator; three impulse signals of deaerator water level, water supply flow and condensate flow act on a condensate pump high-voltage frequency converter under the condition of deep peak shaving of the thermal generator set, so that deaerator water level automatic adjustment is achieved by changing the rotating speed of a condensate pump, and throttling loss of a deaerator water level adjusting valve is reduced.

Under the frequency conversion operation mode of the condensate pump, a three-impulse regulating logic loop of the deaerator water level regulating valve is cut off, and the deaerator water level regulating valve is fully opened, so that throttling loss is reduced to the maximum extent.

And when the frequency conversion device of the condensate pump fails, the condensate pump is automatically switched to a three-impulse-quantity adjusting logic loop of the deaerator water level adjusting valve in a power frequency operation mode.

The frequency conversion regulation control of the outlet pressure of the condensate pump is cancelled, the outlet pressure of the condensate pump is increased and reduced to 1.5MPa, the limitation of locking and reducing the frequency of a motor of the condensate pump is reduced, and the constant value of the low-pressure interlocked starting standby pump of the outlet pressure of the condensate pump is changed from 1.8MPa to 1.3 MPa.

Increase the restriction that condensate pump outlet pressure is low to 1.5MPa shutting and subtracts condensate pump motor frequency, when arbitrary one of two condensate pumps is in frequency conversion state, when the oxygen-eliminating device water level control is the frequency conversion regulatory function, restriction oxygen-eliminating device water level frequency conversion regulatory frequency further reduces the function when condensate pump outlet pressure reduces to 1.5MPa, cut the condensate pump frequency conversion controller into manual regulation state and keep the present valve position of oxygen-eliminating device water level main regulating valve unchangeable by automatic status simultaneously, prevent that condensate pump outlet pressure from crossing unsatisfied condensate water supply demand excessively.

The invention has the beneficial effects that:

the invention discloses a water level three-impulse frequency conversion automatic regulating method of a deaerator of a condensate system under the condition of low load or deep peak shaving of a thermal generator set.

Drawings

FIG. 1 is a schematic view of the structural connection of the present invention;

FIG. 2 is a process flow diagram of the present invention.

Detailed Description

The invention is further described below:

a three-impulse frequency conversion automatic regulation method comprises the following steps

A condensation pump outlet main pipe pressure variable frequency regulation control loop is eliminated, namely a condensation pump regulation PID control loop which sends a regulation instruction to a condensation pump variable frequency controller in a unit DCS control system is eliminated;

adding a three-impulse variable-frequency regulation control loop, introducing three impulses of the water level, the water supply flow and the condensate flow of a deaerator into a cascade regulation controller, correcting the water level deviation by using a regulator, ensuring that the water level has no static deviation, generating a set value of the main condensate flow by an output signal of a main regulator and a feed water flow feedforward signal through the action of the main regulator, applying the deviation of the set value and the actual main condensate flow to an auxiliary regulator, outputting the set value through the auxiliary regulator, and controlling a frequency output signal of variable-frequency regulation of a condensate pump, the rotating speed of the condensate pump is changed through the frequency change, the condensate flow is further changed, the water level regulation of the deaerator is controlled, the main regulator adopts load proportion control to ensure the stable regulation of the main regulation loop, the auxiliary regulator adopts load proportion control, so that the auxiliary loop can be adjusted quickly, and the three-impulse signal acts on the high-voltage frequency converter of the condensation pump, so that the frequency conversion controller of the condensation pump can directly and automatically adjust the water level of the deaerator; three impulse signals of deaerator water level, water supply flow and condensate flow act on a condensate pump high-voltage frequency converter under the condition of deep peak shaving of the thermal generator set, so that deaerator water level automatic adjustment is achieved by changing the rotating speed of a condensate pump, and throttling loss of a deaerator water level adjusting valve is reduced.

Under the frequency conversion operation mode of the condensate pump, a three-impulse regulating logic loop of the deaerator water level regulating valve is cut off, and the deaerator water level regulating valve is fully opened, so that throttling loss is reduced to the maximum extent. And when the frequency conversion device of the condensate pump fails, the condensate pump is automatically switched to a three-impulse-quantity adjusting logic loop of the deaerator water level adjusting valve in a power frequency operation mode. The frequency conversion regulation control of the outlet pressure of the condensate pump is cancelled, the outlet pressure of the condensate pump is increased and reduced to 1.5MPa, the limitation of locking and reducing the frequency of a motor of the condensate pump is reduced, and the constant value of the low-pressure interlocked starting standby pump of the outlet pressure of the condensate pump is changed from 1.8MPa to 1.3 MPa. Increase condensate pump outlet pressure and subtract the restriction of condensate pump motor frequency down to 1.5MPa shutting, when arbitrary one of two condensate pump A and B is in the frequency conversion state, when the oxygen-eliminating device water level regulation is the frequency conversion regulatory function, if the condensate pump outlet pressure reduces to limiting oxygen-eliminating device water level frequency conversion regulatory frequency and further reducing the function when 1.5MPa, cut condensate pump frequency conversion controller into manual regulation state and keep the current valve position of oxygen-eliminating device water level main regulating valve unchangeable by automatic status simultaneously, prevent that condensate pump outlet pressure from crossing unsatisfied condensate water supply demand excessively.

The specific considerations in actual use are as follows:

1. the frequency conversion regulation control loop of the condensation pump outlet main pipe pressure is cancelled, namely a 'condensation pump regulation PID' control loop which sends a regulation instruction to a condensation pump frequency conversion controller in a DCS control system of a unit is cancelled, and correspondingly, the 'condensation pump outlet main pipe pressure' instruction in frequency conversion regulation operation pictures of a condensation pump in an engineer station and an operator station can be input and correspondingly cancelled in a factory.

2. A three-impulse variable-frequency regulation control loop is added, three impulses of the water level, the water supply flow and the condensate flow of a deaerator are introduced into a cascade regulation controller, the regulator has the task of correcting the water level deviation and ensuring that the water level has no static deviation, the cascade regulation main regulation task and the cascade regulation auxiliary regulation task are different, an output signal of a main regulator and a feed water flow feedforward signal generate a set value of the main condensate flow through the action of the main regulator, the deviation of the set value and the actual main condensate flow acts on an auxiliary regulator, the set value and the actual main condensate flow are output through the auxiliary regulator, a frequency output signal of variable-frequency regulation of a condensate pump is controlled, the rotating speed of the condensate pump is changed through frequency change, and then the condensate flow is changed, so that the purpose of regulating the water level of the deaerator is achieved. Due to different tasks, the main regulator adopts proportional-integral control to ensure the regulation stability of the main regulation loop, and the auxiliary regulator adopts proportional control to ensure that the auxiliary loop has rapidity in regulation. The three-impulse signal acts on the high-voltage frequency converter of the condensation pump, and the purpose of directly and automatically adjusting the water level of the deaerator by the frequency conversion controller of the condensation pump is achieved. Correspondingly, frequency conversion adjustment operation pictures of the condensation pump at the engineer station and the operator station are reconfigured, and instruction input and operation frames for adjusting the deaerator water level are added.

3. When any one of the two condensate pumps is in a frequency conversion state, a deaerator water level main regulating valve control loop is cut off, and meanwhile, a deaerator water level main regulating valve is set to be fully opened, so that the problem that the valve opening degree of a traditional deaerator water level regulating valve is too small to throttle and lose a large amount when a unit is under a low load is thoroughly solved.

4. When two condensing pump frequency conversion devices are in fault, quit the frequency conversion mode, and are both in a power frequency state, a deaerator water level frequency conversion regulation control loop is cut off, the deaerator water level control loop is switched to a deaerator water level main regulation valve control loop, the completeness of a deaerator water level regulation function under different operation modes is guaranteed, and production is not affected.

5. Increase the restriction that condensate pump outlet pressure is low to 1.5MPa shutting and subtracts condensate pump motor frequency, when arbitrary one of two condensate pumps is in frequency conversion state, when the oxygen-eliminating device water level control is the frequency conversion regulatory function, restriction oxygen-eliminating device water level frequency conversion regulatory frequency further reduces the function when condensate pump outlet pressure reduces to 1.5MPa, cut into manual regulation state and keep the present valve position of oxygen-eliminating device water level main regulating valve unchangeable with condensate pump frequency conversion controller by automatic status simultaneously, prevent that condensate pump outlet pressure from crossing unsatisfied condensate water user demand excessively.

6. The constant value of the condensate pump outlet pressure low interlocking starting standby pump is adjusted from 1.8MPa to 1.3 MPa. When the unit is under low load or the peak is deeply regulated, in order to reduce the frequency as far as possible to achieve the purpose of variable frequency regulation energy saving but not throttling regulation, through theoretical analysis calculation and actual verification, the requirements of deaerator water level regulation and condensed water users can be met by the pressure of a main pipe of a condensate pump outlet being more than 1.3MPa, and the linkage value of a standby pump under the original regulation mode is too high at 1.8MPa, so that the motor frequency of the condensate pump is not favorably reduced under the low load of the unit.

In order to solve the defect that the throttling loss is large when a unit is under low load in the traditional deaerator water level automatic adjustment of a condensed water system, a three-impulse variable-frequency automatic adjustment idea is provided, firstly, the feasibility of the idea is verified by carrying out a field test, secondly, a specific solution scheme is provided by combining the test, and finally, the scheme is actually verified.

1. Carry out field tests

The method is characterized in that a 350MW supercritical air cooling unit of a certain plant is taken as a test machine type, deep peak regulation is carried out in a mode of gradually reducing unit load by taking 10MW as amplitude, each load point stops, parameters such as condensate flow, condensate pump outlet pressure, deaerator water level, frequency-variable controller output frequency and the like are recorded until the peak regulation load is reduced to 30% of rated load, automatic adjustment of a deaerator water level adjusting valve is removed in the process, the valve opening degree is kept above 90% all the time, namely the deaerator water level adjusting valve does not participate in adjustment, the deaerator water level is adjusted by adopting a method of manually and gradually reducing the frequency of the condensate pump frequency-variable controller by random load reduction, test results show that the frequency can be reduced to 37Hz at the lowest, at the moment, the condensate flow and the pressure meet the requirement of water supplement to the deaerator, and the deaerator water level is controllable.

The other purpose of the condensate water of the power plant is to provide seal water or cooling water for a rotating machine such as a water feeding pump and the like, and simultaneously provide temperature-reduced water, called as 'condensate water', for some systems, if the frequency of a frequency converter of the condensate pump is reduced, namely the rotating speed of the condensate pump is reduced, the pressure of the outlet of the condensate pump is possibly too low, and the technological requirement of a condensate water user on the pressure of the condensate water cannot be met. The test result shows that when the peak load of the unit is 30% (reaching the peak regulation limit of the domestic unit without oil injection and stable combustion), the outlet pressure of the condensate pump is 1.7MPa, and the requirement of the condensate water user on the pressure parameter of the condensate water is also met.

Therefore, in the peak load regulation range, test results show that the adjusting method for reducing the throttling loss by changing the frequency of the condensation pump and opening the deaerator water level regulating valve is feasible.

The above tests are completed under the condition of removing all automation, and the unit can meet the requirements of stable operation, labor intensity reduction and quality regulation only by realizing automatic regulation in the actual operation, so that a brand new control strategy and control scheme need to be designed on the basis of the tests to achieve the purpose of automatic regulation.

2. Novel control strategy

(1) The pressure frequency conversion regulation control loop of the condensate pump outlet main pipe is cancelled, and when the condensate pump runs in a frequency conversion mode, the high-voltage frequency converter only changes the condensate flow rate according to the three impulse quantities of the water level, the water supply flow rate and the condensate flow rate of the deaerator by changing the motor frequency of the condensate pump to realize the purpose of adjusting the water level of the deaerator. This completely new regulation mode makes it possible to switch from conventional pressure regulation to flow regulation.

(2) In order to solve the defects that the throttling loss of the system is large and the operation mode is not economical due to the coexistence of two sets of automatic regulating systems (namely a deaerator water level regulating valve three-impulse automatic regulating system and a condensing pump outlet pressure frequency conversion automatic regulating system) in the original condensed water system, after the new three-impulse frequency conversion automatic regulating system is put into use, the deaerator water level regulating valve three-impulse automatic regulating system is cut off, namely, the deaerator water level regulating valve does not participate in regulation in the frequency conversion normal operation mode of the condensing pump, the valve is kept fully opened, only the condensing pump three-impulse automatic frequency conversion regulating system is put into use and participates in regulation in the system, the purpose of reducing the throttling loss to the maximum degree is realized, and the energy-saving advantages of high-voltage frequency conversion regulation are fully exerted.

(3) In order to realize the conversion of the regulation mode from pressure regulation to flow regulation, the invention adds a three-impulse variable-frequency regulation control loop. In fact, the adjustment of the water level of the deaerator only needs to directly adjust the flow of the condensed water, namely, single impulse adjustment, but in order to improve the adjustment quality and stability and the quick response of adjustment, the water level adjustment of an important system in the field of thermal power generation usually adopts three impulse adjustments, which is a conventional method and is not repeated herein.

(4) One of the core contents of the invention is to change the motor frequency (i.e. change the flow of the condensed water) through the high-voltage frequency converter of the condensate pump to achieve the purpose of regulating the water level of the deaerator, that is, to establish the functional relationship between the frequency and the flow of the condensed water, namely, the establishment of the frequency characteristic function f (x). After the frequency characteristic function F (x) is established, the frequency characteristic function F (x) outputs the frequency corresponding to the water level (or the flow rate of the condensate water) of the deaerator, and the frequency is used as an input instruction of the condensate pump frequency conversion controller to change the rotating speed of a motor of the condensate pump, so that the automatic adjustment of the water level of the deaerator is realized.

According to the related knowledge of fluid mechanics, the outlet flow rate of the water pump is proportional to the rotation speed of the pump, because the rotation speed and the frequency are in a one-to-one correspondence relationship, the functional relationship between the frequency and the condensate flow rate in the frequency characteristic function f (x) established in the future is necessarily a linear function expression, namely f (x) = kx + b, and if k and b are known in the formula, the frequency characteristic function f (x) is determined.

According to the method for the field test, deep peak regulation is carried out in a mode of gradually reducing the unit load with the amplitude of 10MW, the frequency of the condensate pump is manually changed, and test data of multiple groups of frequencies and condensate flow are obtained. It is known that for the equation of a binary system y = kx + b, k and b can be found from two sets of data in a series of equations, and the frequency characteristic function f (x) is determined.

(5) In actual production, the high-voltage frequency conversion device fault is a large probability event which cannot be put into operation, when two condensation pump frequency conversion devices have faults, the condensation pump frequency conversion devices exit from a frequency conversion mode and are in a power frequency state, a three-impulse frequency conversion regulation control loop is cut off, a deaerator water level control loop is switched into a deaerator water level main regulating valve control loop, the completeness of a deaerator water level regulation function under different operation modes is guaranteed, and production is not affected. And after the fault processing of the frequency conversion device is finished, switching to a three-impulse frequency conversion regulation mode.

(6) Increase the restriction that condensate pump outlet pressure is low to 1.5MPa shutting and subtracts condensate pump motor frequency, when arbitrary one of two condensate pumps is in frequency conversion state, when the oxygen-eliminating device water level control is the frequency conversion regulatory function, restriction oxygen-eliminating device water level frequency conversion regulatory frequency further reduces the function when condensate pump outlet pressure reduces to 1.5MPa, cut into manual regulation state and keep the present valve position of oxygen-eliminating device water level main regulating valve unchangeable with condensate pump frequency conversion controller by automatic status simultaneously, prevent that condensate pump outlet pressure from crossing unsatisfied condensate water user demand excessively.

(7) The constant value of the condensate pump outlet pressure low interlocking starting standby pump is adjusted from 1.8MPa to 1.3 MPa. When the unit is under low load or the peak is deeply regulated, in order to reduce the frequency as far as possible to achieve the purpose of variable frequency regulation energy saving but not throttling regulation, through theoretical analysis calculation and actual verification, the requirements of deaerator water level regulation and condensed water users can be met by the pressure of a main pipe of a condensate pump outlet being more than 1.3MPa, and the linkage value of a standby pump under the original regulation mode is too high at 1.8MPa, so that the motor frequency of the condensate pump is not favorably reduced under the low load of the unit.

3. Scheme actual verification

The deaerator has the highest operating pressure when the unit is in full-load operation, condensed water can be supplemented when the pressure of the condensed water must meet the highest pressure of the deaerator, namely the condensed water overcomes all resistance of the system, taking a 350MW supercritical air cooling unit as an example, the deaerator has the operating pressure of 0.75MPa when the unit is in full-load, the maximum resistance of a condensed water fine treatment system is 0.1MPa, the maximum resistance of a heat recovery system heater is 0.2MPa, the deaerator is arranged at the elevation of 22 meters, the elevation static pressure resistance and the pipeline resistance are calculated according to 0.25MPa, the total resistance of the system is 1.3MPa, the frequency conversion controller has the lowest output frequency of 37Hz and the condensed water pressure is 1.7MPa during the actual peak regulation of the unit on machine, and the regulation requirement is completely met.

According to the method, the existing control strategy is modified, full peak regulation stage (30-100% rated load) test verification is carried out, the deaerator water level three-impulse frequency conversion automatic regulation characteristic curve is converged without oscillation, the regulation quality is good, the regulation requirement is met, and the problem of large throttling loss of the regulating valve is thoroughly solved.