Steam temperature control method, device and equipment, storage medium and product

Abstract

The invention discloses a steam temperature control method and device, equipment, a storage medium and a product. The method comprises the steps that whether integral saturation occurs in the superheated steam temperature control process or not is determined according to a temperature measurement value after water spraying, a temperature set value after water spraying, a superheated steam temperature measurement value and a temperature reduction water valve control value; when integral saturation occurs in the superheated steam temperature control process, the first regulator outputs a post-water-spraying temperature set value according to the superheated steam temperature measurement value and the post-water-spraying temperature measurement value; the second regulator outputs the temperature reduction water valve control value at the current moment according to the temperature measurement value after water spraying and the temperature reduction water valve control value at the previous moment; when integral saturation does not occur in the superheated steam temperature control process, the first regulator outputs a temperature set value after water spraying according to the superheated steam temperature measurement value and the superheated steam temperature set value; and the second regulator outputs a temperature reduction water valve control value according to the post-water-spraying temperature measurement value and the post-water-spraying temperature set value.

Description

Technical Field

[0001] The embodiments of the present invention relate to automatic control technology, and in particular to a steam temperature control method, device, equipment, storage medium and product. Background Art

[0002] Superheated steam temperature is one of the important indicators of boiler operation. Maintaining the superheated steam temperature within the specified range is an important guarantee for the safe and economical operation of the power plant. Maintaining the stability of the superheated steam temperature, controlling the superheated steam temperature within the allowable range, and ensuring that the entire superheater does not overheat are important tasks of the superheated steam temperature control system. Too high a temperature may cause damage to the metal materials of the superheater, steam pipes and high-pressure parts of the steam turbine, reducing the service life; too low a temperature will reduce the cycle thermal efficiency of the power plant and affect the safe and economical operation of the steam turbine. Excessive changes in steam temperature will lead to fatigue of the metal pipes and components of the boiler and steam turbine, endangering the safety of the unit.

[0003] Changes in the main steam pressure, combustion conditions, soot blowing, boiler air volume, etc. of a thermal power plant are all factors that affect the change in steam temperature, which will cause fluctuations in steam temperature and cause the superheated steam temperature and reheated steam temperature to deviate from the set values ​​for a long time. Therefore, strengthening the effective control of superheated steam temperature is the key to ensuring the safe operation of the unit and improving the control quality. Most of the existing superheated steam temperature control systems for units do not take into account the problem of controller integral saturation, which results in the superheated steam temperature of the unit being unable to return to normal values ​​for a long time under low temperature or overtemperature conditions caused by external disturbances. The implementation of the present invention can effectively solve the integral saturation problem of the superheated steam control system, thereby making the superheated steam control of the generator set more stable and safe.

[0004] The existing steam temperature control method for generator sets to resist integral saturation starts with correcting the inlet deviation and integral time of the main desuperheating water regulator, and does not perform corresponding processing on the sub-regulator, which may lead to deviations in the judgment of integral saturation. At the same time, the parameter setting of the existing method is relatively complicated, and it takes a certain amount of time to set the appropriate parameters, which is not easy for thermal engineers of power plants to master. Summary of the invention

[0005] The present invention provides a steam temperature control method, device, equipment, storage medium and product to reduce the difficulty of superheated steam temperature control and improve the stability of superheated steam temperature control.

[0006] In a first aspect, an embodiment of the present invention provides a steam temperature control method, comprising:

[0007] Determine whether integral saturation occurs during the superheated steam temperature control process according to the measured value of the temperature after water spraying, the set value of the temperature after water spraying, the measured value of the superheated steam temperature and the control value of the desuperheating water valve;

[0008] When integral saturation occurs during the superheated steam temperature control process, the first regulator outputs a post-water spraying temperature set value according to the superheated steam temperature measurement value and the post-water spraying temperature measurement value;

[0009] The second regulator outputs the control value of the cooling water valve at the current moment according to the temperature measurement value after water spraying and the control value of the cooling water valve at the previous moment;

[0010] When integral saturation does not occur during the superheated steam temperature control process, the first regulator outputs a post-water spraying temperature setting value according to the superheated steam temperature measurement value and the superheated steam temperature setting value;

[0011] The second regulator outputs a control value of the cooling water valve according to a measured value of the temperature after water spraying and a set value of the temperature after water spraying.

[0012] Optionally, the first logic value is determined according to a measured value of the temperature after water spraying and a set value of the temperature after water spraying;

[0013] determining a second logic value based on the superheated steam temperature measurement value;

[0014] Determining a third logic value according to the temperature reducing water valve control value;

[0015] A fourth logic value is determined according to the first logic value, the second logic value and the third logic value. If the fourth logic value is 1, it is determined that integral saturation occurs; if the fourth logic value is 0, it is determined that integral saturation does not occur.

[0016] Optionally, it also includes determining the delay time according to the load value of the unit;

[0017] The delay time is used when the integral saturation occurs. After the delay time, the first regulator outputs the post-water spraying temperature setting value according to the superheated steam temperature measurement value and the post-water spraying temperature measurement value;

[0018] The second regulator outputs the control value of the cooling water valve at the current moment according to the temperature measurement value after the water spraying and the control value of the cooling water valve at the previous moment.

[0019] Optionally, it further includes determining the delay time using a first function according to the load value of the unit when the unit is in a steady state;

[0020] When the unit is in dynamic state, the delay time is determined by using a second function according to the load value of the unit.

[0021] Optionally, determining a difference between the measured value of the temperature after water spraying and the set value of the temperature after water spraying, if the difference is greater than a first threshold, the first logic value is 1, otherwise it is 0;

[0022] If the superheated steam temperature measurement value is greater than a second threshold value, the second logic value is 1, otherwise it is 0;

[0023] If the temperature-reducing water valve control value is greater than the third threshold, the third logic value is 1, otherwise it is 0.

[0024] Optionally, the steam temperature control method is used for temperature control of superheated steam in a boiler.

[0025] In a second aspect, an embodiment of the present invention further provides a steam temperature control device, including a steam temperature control unit, wherein the steam temperature control unit is used to:

[0026] Determine whether integral saturation occurs during the superheated steam temperature control process according to the measured value of the temperature after water spraying, the set value of the temperature after water spraying, the measured value of the superheated steam temperature and the control value of the desuperheating water valve;

[0027] When integral saturation occurs during the superheated steam temperature control process, the first regulator outputs a post-water spraying temperature set value according to the superheated steam temperature measurement value and the post-water spraying temperature measurement value;

[0028] The second regulator outputs the control value of the cooling water valve at the current moment according to the temperature measurement value after water spraying and the control value of the cooling water valve at the previous moment;

[0029] When integral saturation does not occur during the superheated steam temperature control process, the first regulator outputs a post-water spraying temperature setting value according to the superheated steam temperature measurement value and the superheated steam temperature setting value;

[0030] The second regulator outputs a control value of the cooling water valve according to a measured value of the temperature after water spraying and a set value of the temperature after water spraying.

[0031] In a third aspect, an embodiment of the present invention further provides an electronic device, comprising at least one processor, and a memory communicatively connected to the at least one processor;

[0032] The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute any one of the steam temperature control methods described in the embodiments of the present invention.

[0033] In a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement any one of the steam temperature control methods recorded in the embodiments of the present invention when executed.

[0034] In a fifth aspect, an embodiment of the present invention further provides a computer program product, including a computer program, which, when executed by a processor, implements any one of the steam temperature control methods described in the embodiments of the present invention.

[0035] Compared with the prior art, the beneficial effect of the present invention is that: the present invention proposes a steam temperature control method, in which a main regulator and a sub-regulator are configured to perform PID control according to different set values ​​when integral saturation occurs and when integral saturation does not occur. In addition, when integral saturation does not occur, the main regulator outputs a corresponding control signal to adjust the set value of the sub-regulator to cause the superheated steam temperature to approach the set value. When integral saturation occurs, the main regulator does not output a corresponding control signal to adjust the set value of the sub-regulator, and the sub-regulator is used to independently control the flow rate of cooling water. By processing the inlet deviation of the superheater cooling water main regulator and the sub-regulator under the condition of integral saturation (the inlet deviation refers to the difference between the measured value of the main controlled variable of the system and the main set value. For example, in a boiler superheated steam temperature cascade control system, the main controlled variable is the superheated steam temperature, and the inlet deviation of the main regulator is the difference between the actual superheated steam temperature and the expected superheated steam temperature set value), the integral saturation of the superheater cooling water regulator can be effectively suppressed, and the control process of the superheater cooling water can be optimized. In this scheme, whether integral saturation occurs in the process of superheated steam temperature control is determined according to the temperature measurement value after water spraying, the temperature setting value after water spraying, the superheated steam temperature measurement value and the control value of the cooling water valve. The design parameter setting is relatively simple. It only needs to adjust the inlet deviation limit of the sub-regulator according to the actual operation of the cooling water valve. Any DCS (Distributed Control System) system can be easily implemented. In this scheme, when integral saturation occurs, the sub-regulator maintains the cooling water valve control value (PID output) based on the previous cycle, so that the PID output is stable near the cooling water valve control value of the previous cycle, and the cooling water valve control value is used to control the flow of cooling water. When it is maintained based on the output value of the previous cycle, it means that in the current control cycle, the output of the controller does not perform a new calculation, but directly uses the output value of the previous cycle. By maintaining the output value of the previous cycle, the integral term can be prevented from continuing to accumulate in the current cycle, thereby preventing the output from further deviating from the reasonable range. Maintaining the output value of the previous cycle allows the system to have a certain amount of time to stabilize, and observe the change trend of the system before making more appropriate control adjustments. When integral saturation occurs, the main regulator tracks the measured value of the temperature after water spraying and outputs the set value of the water spraying temperature (that is, the measured value of the temperature after water spraying is used as the set value, and PID calculation is performed based on the difference between the measured value of the superheated steam temperature and the measured value of the temperature after water spraying, and then the set value of the water spraying temperature is obtained). Through this tracking and maintaining control, when the integral saturation problem is eliminated and normal control is restored, since the set value of the water spraying temperature is close to the measured value of the temperature after water spraying, when the set value of the water spraying temperature is used as the set value of the sub-regulator, the sub-regulator re-calculates the PID based on the difference between the measured value of the temperature after water spraying and the measured value of the temperature after water spraying to output the control value of the cooling water valve, the disturbance to the system when returning to normal regulation can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a flow chart of the steam temperature control method in the embodiment;

[0037] Figure 2 is a steam temperature control block diagram in an embodiment;

[0038] Figure 3 is another steam temperature control block diagram in the embodiment;

[0039] Figure 4 is another steam temperature control block diagram in the embodiment;

[0040] Figure 5 Schematic diagram of the structure of an electronic device in an embodiment. DETAILED DESCRIPTION

[0041] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0042] Embodiment 1

[0043] Figure 1 is a flow chart of the steam temperature control method in the embodiment, refer to Figure 1 , steam temperature control methods include:

[0044] S101. Determine whether integral saturation occurs during the superheated steam temperature control process based on the measured value of the temperature after water spraying, the set value of the temperature after water spraying, the measured value of the superheated steam temperature, and the control value of the desuperheating water valve.

[0045] In this embodiment, the steam temperature control method is set to control the temperature of the superheated steam in the boiler.

[0046] In this scheme, the PID control method is used to determine the control quantity in the steam temperature control, wherein integral saturation refers to the phenomenon that in the PID controller, due to the continuous accumulation of integral action, the output of the controller reaches the limit value (such as the maximum value or the minimum value) and cannot be restored to the normal range within a period of time;

[0047] In steam temperature control, when the steam temperature deviates greatly from the set value, the integral term increases continuously, causing the controller output (such as regulating valve opening) to reach the limit position. Even if the steam temperature begins to approach the set value, the controller output cannot be adjusted in time due to the cumulative effect of the integral term, thus affecting the timeliness and accuracy of the control.

[0048] In addition, when there is a large deviation between the steam temperature and the set value and it lasts for a period of time, the integral term in the PID controller will continue to accumulate. For example, due to a sudden change in external load or a system failure, the steam temperature deviates significantly from the set value. At this time, the integral action will continue to increase in an attempt to eliminate the deviation, causing the controller output to increase or decrease continuously until it reaches the limit value.

[0049] In this scheme, when the temperature of superheated steam needs to be lowered, an appropriate amount of water can be sprayed into the steam. Water will quickly vaporize after contacting the high-temperature steam, absorbing the heat of the steam, thereby lowering the temperature of the steam. This process is based on the principle of heat exchange, absorbing the heat of the steam through the latent heat of vaporization of water, and lowering the steam temperature;

[0050] For example, at the outlet of the boiler superheater, if the steam temperature is detected to be too high, a certain amount of water can be sprayed into the steam through a water spray desuperheater. The water vaporizes instantly under the action of the high-temperature steam, absorbs the heat of the steam, and reduces the steam temperature to the required range;

[0051] The temperature measurement value after water spraying indicates the measurement value of the steam after being cooled by water spraying;

[0052] The temperature setting value after water spraying represents a preset temperature threshold value, which can be determined by experiment or experience;

[0053] The measured value of superheated steam temperature represents the measured value of superheated steam without water spray cooling;

[0054] The temperature reducing water valve control value represents the control amount for the temperature reducing water valve, and the control amount is calculated by the PID controller.

[0055] In this scheme, there is no limitation on the method of determining whether integral saturation occurs based on the measured value of the temperature after water spraying, the set value of the temperature after water spraying, the measured value of the superheated steam temperature, and the control value of the desuperheating water valve;

[0056] For example, based on the operating characteristics of the desuperheating water valve, historical data of the temperature measurement value after water spraying, the temperature setting value after water spraying, the superheated steam temperature measurement value, and the desuperheating water valve control value can be collected. By analyzing the historical data curve, the numerical range of the above values ​​when integral saturation occurs can be determined. In the actual operation process, whether integral saturation occurs can be determined by looking up the table.

[0057] Alternatively, a neural network model may be established, and based on the above-mentioned values ​​obtained, whether integral saturation occurs may be determined through the trained neural network model.

[0058] S102. When integral saturation occurs during the superheated steam temperature control process, the first regulator outputs a post-water spraying temperature set value based on the superheated steam temperature measurement value and the post-water spraying temperature measurement value.

[0059] S103. The second regulator outputs the cooling water valve control value at the current moment according to the temperature measurement value after water spraying and the cooling water valve control value at the previous moment.

[0060] S104. When integral saturation does not occur during the superheated steam temperature control process, the first regulator outputs a post-water spraying temperature setting value based on the superheated steam temperature measurement value and the superheated steam temperature setting value.

[0061] S105. The second regulator outputs the cooling water valve control value according to the temperature measurement value after water spraying and the temperature setting value after water spraying.

[0062] In combination with steps S102 to S105, in this solution, the first regulator is set as the main regulator and the second regulator is set as the auxiliary regulator;

[0063] The main regulator continuously monitors the actual temperature of the superheated steam, compares it with the desired temperature setting value, and calculates the temperature deviation. Then, according to the size and change trend of the deviation, it outputs the corresponding control signal to adjust the setting value of the sub-regulator to make the superheated steam temperature approach the setting value;

[0064] Specifically, when integral saturation does not occur, the main regulator is set to perform proportional integral (PI) or proportional integral differential (PID) regulation according to the deviation between the superheated steam temperature measurement value and the superheated steam temperature setting value, and then output the post-water spraying temperature setting value;

[0065] The auxiliary regulator is used to perform proportional integral (PI) or proportional integral differential (PID) regulation according to the deviation between the temperature measurement value after water spraying and the temperature setting value after water spraying, and then output the control value of the cooling water valve. The auxiliary regulator directly controls the cooling water volume based on the cooling water valve control value. In the case of internal disturbance of the cooling water (such as fluctuation of cooling water pressure, change of cooling water valve opening, etc.), the auxiliary regulator can quickly adjust the cooling water flow rate according to the change of the temperature measurement value after water spraying to eliminate the influence of the internal disturbance on the superheated steam temperature;

[0066] The regulating function of the sub-regulator can be regarded as a rough adjustment of the superheated steam temperature. Under the command of the main regulator, it can quickly change the amount of cooling water to keep the steam temperature at the superheater inlet within a certain range.

[0067] In this scheme, when integral saturation occurs, the main regulator is set to perform proportional integral (PI) or proportional integral differential (PID) regulation according to the deviation between the superheated steam temperature measurement value and the post-water spray temperature measurement value, and then output the post-water spray temperature set value;

[0068] The auxiliary regulator is used to perform proportional integral (PI) or proportional integral differential (PID) regulation according to the deviation between the temperature measurement value after water spraying and the control value of the superheating water valve at the previous moment, and then output the control value of the superheating water valve at the current moment;

[0069] In this scheme, when integral saturation occurs, the main regulator does not output the corresponding control signal to adjust the set value of the sub-regulator. The sub-regulator is used to independently control the cooling water flow rate. The post-water spraying temperature set value output by the main regulator is still used as the basis for judging whether integral saturation occurs.

[0070] Exemplarily, in this solution, one or two PID control equations can be configured in the main regulator. When one PID equation is configured, the same PID equation (including the same PID parameters) can be used to output the set value of the temperature after water spraying when integral saturation occurs and when integral saturation does not occur;

[0071] When two PID equations are configured, the corresponding PID equations can be used to output the set value of the temperature after water spraying when integral saturation occurs and when integral saturation does not occur;

[0072] One or two PID control equations can also be configured in the sub-regulator. When one PID equation is configured, the same PID equation (including the same PID parameters) can be used to output the control value of the cooling water valve when integral saturation occurs and when integral saturation does not occur.

[0073] When two PID equations are configured, the corresponding PID equations can be used to output the control value of the cooling water valve when integral saturation occurs and when integral saturation does not occur.

[0074] This embodiment proposes a steam temperature control method, in which a main regulator and a sub-regulator are configured to perform PID control according to different set values ​​when integral saturation occurs and when integral saturation does not occur. In addition, when integral saturation does not occur, the main regulator outputs a corresponding control signal to adjust the set value of the sub-regulator to cause the superheated steam temperature to approach the set value. When integral saturation occurs, the main regulator does not output a corresponding control signal to adjust the set value of the sub-regulator, and the sub-regulator is used to independently control the desuperheating water flow rate. By processing the inlet deviation of the superheater desuperheating water main regulator and the sub-regulator under the integral saturation condition (the inlet deviation refers to the difference between the measured value of the main controlled variable of the system and the main set value. For example, in a boiler superheated steam temperature cascade control system, the main controlled variable is the superheated steam temperature, and the inlet deviation of the main regulator is the difference between the actual superheated steam temperature and the expected superheated steam temperature set value), the integral saturation of the superheater desuperheating water regulator can be effectively suppressed, and the control process of the superheater desuperheating water can be optimized.

[0075] In this scheme, whether integral saturation occurs in the superheated steam temperature control process is determined according to the temperature measurement value after water spraying, the temperature setting value after water spraying, the superheated steam temperature measurement value and the desuperheating water valve control value. The design parameter setting is relatively simple. It only needs to set the inlet deviation limit of the sub-regulator according to the actual operation of the desuperheating water valve. Any DCS (Distributed Control System) system can be easily implemented.

[0076] In this scheme, when integral saturation occurs, the sub-regulator maintains the control value (PID output) of the cooling water valve based on the previous cycle, so that the PID output is stable near the cooling water valve control value of the previous cycle, and the cooling water valve control value is used to control the flow of cooling water. When it is maintained based on the output value of the previous cycle, it means that in the current control cycle, the output of the controller does not perform a new calculation, but directly uses the output value of the previous cycle. By maintaining the output value of the previous cycle, the integral term can be prevented from continuing to accumulate in the current cycle, thereby preventing the output from further deviating from a reasonable range. Maintaining the output value of the previous cycle allows the system to have a certain amount of time to stabilize, and more appropriate control adjustments can be made after observing the changing trend of the system. When integral saturation occurs, the main regulator tracks the measured value of the temperature after water spraying and outputs the set value of the water spraying temperature (that is, the measured value of the temperature after water spraying is used as the set value, and PID calculation is performed based on the difference between the measured value of the superheated steam temperature and the measured value of the temperature after water spraying, and then the set value of the water spraying temperature is obtained). Through this tracking and maintaining control, when the integral saturation problem is eliminated and normal control is restored, since the set value of the water spraying temperature is close to the measured value of the temperature after water spraying, when the set value of the water spraying temperature is used as the set value of the sub-regulator, the sub-regulator re-calculates the PID based on the difference between the measured value of the temperature after water spraying and the measured value of the temperature after water spraying to output the control value of the cooling water valve, the disturbance to the system when returning to normal regulation can be reduced.

[0077] exist Figure 1 On the basis of the scheme shown, in one possible implementation scheme, the first logic value is determined according to the temperature measurement value after water spraying and the temperature setting value after water spraying; the second logic value is determined according to the superheated steam temperature measurement value; and the third logic value is determined according to the temperature reduction water valve control value;

[0078] A fourth logic value is determined according to the first logic value, the second logic value, and the third logic value. If the fourth logic value is 1, it is determined that integral saturation occurs. If the fourth logic value is 0, it is determined that integral saturation does not occur.

[0079] Exemplarily, in this solution, the corresponding numerical value can be converted into a logical value based on a preset threshold value. For example, the difference between the temperature measurement value after water spraying and the temperature setting value after water spraying can be determined. If the difference is greater than the first threshold value, the first logical value is 1, otherwise it is 0;

[0080] If the measured value of the superheated steam temperature is greater than the second threshold value, the second logic value is 1, otherwise it is 0;

[0081] If the temperature reducing water valve control value is greater than the third threshold value, the third logic value is 1, otherwise it is 0.

[0082] Exemplarily, in this solution, the first logic value, the second logic value, and the third logic value are set to obtain a fourth logic value after one or more logic operations;

[0083] In this solution, based on historical data and the method for determining the true values ​​of the first logic value, the second logic value and the third logic value, the logical operation used to determine the fourth logic value can be determined experimentally to ensure accurate judgment on whether integral saturation occurs.

[0084] Figure 2 This is a steam temperature control block diagram in the embodiment, refer to Figure 2 , in one possible implementation, the fourth logic value may be generated as follows;

[0085] A first H / L unit, a second H / L unit and a third H / L unit are configured, wherein the first H / L unit is configured to determine a first logic value, the second H / L unit is configured to determine a second logic value, and the third H / L unit is configured to determine a third logic value.

[0086] Exemplarily, in this scheme, the H / L unit is used to compare the size relationship between two input values ​​and output the corresponding logic value according to the comparison result. The H / L unit is configured with two output ports H and L. When the input condition meets a specific "high" logic standard (for example, the current temperature is higher than the set high temperature threshold), the H port outputs a high-level signal. When the input condition meets a specific "low" logic standard (for example, the current temperature is lower than the set low temperature threshold), the L port outputs a low-level signal.

[0087] In this scheme, the first H / L unit is set to compare the difference (the measured value of the temperature after water spraying and the set value of the temperature after water spraying) with the first threshold, the second H / L unit is used to compare the measured value of the superheated steam temperature with the second threshold, and the third H / L unit is used to compare the control value of the desuperheating water valve (the desuperheating water valve instruction) with the third threshold;

[0088] The H port of the first H / L unit, the L port of the second H / L unit, and the L port of the third H / L unit are connected to the first AND operation logic unit;

[0089] The L port of the first H / L unit, the H port of the second H / L unit, and the H port of the third H / L unit are connected to the second AND operation logic unit;

[0090] The first AND operation logic unit and the second AND operation logic unit are connected to an OR operation logic unit, and the output result of the OR operation logic unit is used as the true value of the fourth logic value.

[0091] In one possible implementation, the corresponding numerical value may be converted into a logical value based on a preset threshold value. For example, the difference between the measured temperature value after water spraying and the set temperature value after water spraying may be determined. If the difference is less than a fifth threshold value, the first logical value is 1, otherwise it is 0.

[0092] If the measured value of the superheated steam temperature is less than the sixth threshold value, the second logic value is 1, otherwise it is 0;

[0093] If the temperature reducing water valve control value is less than the seventh threshold value, the third logic value is 1, otherwise it is 0.

[0094] The first logic value, the second logic value, and the third logic value are set to obtain a fourth logic value through one or more logic operations. If the fourth logic value is 1, it is determined that integral saturation occurs, otherwise it is determined that integral saturation does not occur.

[0095] Based on any of the foregoing solutions, in one possible implementation, the steam temperature control method further includes determining a delay time according to a unit load value;

[0096] The delay time is used when integral saturation occurs. After the delay time, the first regulator outputs the set value of the temperature after water spraying according to the measured value of the superheated steam temperature and the measured value of the temperature after water spraying;

[0097] The second regulator outputs the control value of the cooling water valve at the current moment according to the temperature measurement value after the water spraying and the control value of the cooling water valve at the previous moment.

[0098] Exemplarily, in this scheme, the unit load value represents the amount of steam generated or the heat output by the boiler per unit time, usually expressed in units such as megawatts (MW) and tons / hour (t / h). After obtaining the unit load value, the delay time is calculated by a preset function.

[0099] Figure 3 This is another steam temperature control block diagram in the embodiment, refer to Figure 3 In one possible implementation scheme, the preset function F(X) can be determined through simulation experiments, and the delay time determined by the preset function F(X) is used to set a delayed on / off for the tracking / holding signal, that is, when the fourth logic value is 1, the tracking / holding signal acts on the main regulator and the sub-regulator after a certain delay.

[0100] For example, in this solution, the steam temperature control method is applicable to the application scenarios of supercritical and ultra-supercritical direct current furnace units. The purpose of setting the delay on and off is:

[0101] In actual operation, the measured steam temperature and other signals may experience short-term abnormal fluctuations due to various interferences. If there is no delay on-off setting, these instantaneous signal fluctuations may be misjudged by the control system as the need for water spray cooling adjustment, resulting in frequent operation of the cooling water regulating valve. After setting the delay on-off, the control system will make judgments and actions after the signal changes for a period of time, avoiding unnecessary adjustment operations caused by signal fluctuations, reducing system malfunctions, and making water spray cooling control more stable;

[0102] When there is a continuous deviation in the system, the integral effect will continue to accumulate, causing the controller output to increase or decrease continuously, which can easily lead to integral saturation. Setting the delay on and off can slow down the accumulation of integral to a certain extent, giving the system a buffer time, allowing the controller to make a more accurate judgment on the trend of deviation changes, and avoiding over-adjustment caused by excessive accumulation of integral;

[0103] If the water spray cooling control system is adjusted frequently, the cooling water regulating valve will be constantly opened and closed, which will cause the valve core, seals and other parts of the regulating valve to wear more severely, shortening the service life of the regulating valve. By setting the delay on and off, the number of times the regulating valve is operated can be reduced, the degree of wear can be reduced, the service life of the equipment can be extended, and the risk of production interruption caused by equipment failure can be reduced;

[0104] Integral saturation may cause a large change in the output of the water spray cooling control, causing the steam temperature to fluctuate greatly in a short period of time. Such large temperature fluctuations will cause thermal stress shocks to the metal structures of the boiler and related equipment, affecting the safety and reliability of the equipment. Setting the delay on and off can make the output of the control system more stable, reduce the large fluctuations in steam temperature, reduce the impact of thermal stress on the equipment, and protect the safe operation of the equipment;

[0105] In the water spray cooling control, the dynamic characteristics of the system are relatively complex, with large delays and large inertia. Integral saturation will cause the output of the control system to lose control, resulting in a decrease in the stability of the system. Setting the delay on and off can help the control system better adapt to the dynamic characteristics of the system, make the control process more stable, and improve the system's anti-interference ability;

[0106] By setting a reasonable delay on-off time, the control system can adjust when the steam temperature changes relatively stably, avoiding inaccurate adjustment when the temperature changes drastically. This can improve the accuracy of water spray cooling control, make the steam temperature closer to the set value, and meet the requirements of the production process.

[0107] exist Figure 3 On the basis of the scheme shown, in one possible implementation scheme, it further includes, when the unit is in a steady state, using a first function to determine the delay time according to the load value of the unit;

[0108] When the unit is in dynamic state, the second function is used to determine the delay time according to the unit load value.

[0109] Figure 4 This is another steam temperature control block diagram in the embodiment, refer to Figure 4 ,In an implementable solution, the first function F(X1) and the second function F(X1) are determined through simulation tests, and the steam temperature control method is suitable for the application scenario of a subcritical drum boiler unit;

[0110] In this scheme, the unit is in steady state, which means that the parameters of the unit, such as steam pressure, temperature, flow, water level, etc., remain relatively stable. The boiler burns stably, the amount of steam generated matches the steam intake of the turbine, and the generator output power is stable to meet the needs of the power grid;

[0111] The unit is in dynamic state, which means that when it is started from a cold state, the temperature and pressure are gradually increased, including first igniting the boiler. As the combustion progresses, the boiler water temperature gradually increases, steam is generated and enters the steam drum, and the steam pressure gradually increases. When a certain pressure is reached, the turbine starts to run.

[0112] Reference Image Figure 1 and 3 Based on any of the above schemes, in one possible implementation scheme, the steam temperature control method includes:

[0113] S101. Determine whether integral saturation occurs during the superheated steam temperature control process based on the measured value of the temperature after water spraying, the set value of the temperature after water spraying, the measured value of the superheated steam temperature, and the control value of the desuperheating water valve.

[0114] In this scheme, the first H / L unit is set to compare the difference (the measured value of the temperature after water spraying and the set value of the temperature after water spraying) with the first threshold, the second H / L unit is used to compare the differential of the measured value of the superheated steam temperature with the second threshold, and the third H / L unit is used to compare the control value of the desuperheating water valve (the desuperheating water valve instruction) with the third threshold;

[0115] The H port of the first H / L unit, the L port of the second H / L unit, and the L port of the third H / L unit are connected to the first AND operation logic unit;

[0116] The L port of the first H / L unit, the H port of the second H / L unit, and the H port of the third H / L unit are connected to the second AND operation logic unit;

[0117] The first AND operation logic unit and the second AND operation logic unit are connected to an OR operation logic unit, and the output result of the OR operation logic unit is used as the true value of the fourth logic value.

[0118] In this scheme, if the difference is set to be greater than the first threshold, the output of the H port of the first H / L unit is 1, otherwise it is 0;

[0119] If the differential of the measured value of the superheated steam temperature is greater than the second threshold, the output of the H port of the second H / L unit is 1, otherwise it is 0;

[0120] If the control value of the cooling water valve is greater than the third threshold, the output of the H port of the third H / L unit is 1, otherwise it is 0;

[0121] If the fourth logic value is 1, it is determined that integral saturation occurs, and if the fourth logic value is 0, it is determined that integral saturation does not occur.

[0122] S102. When integral saturation occurs during the superheated steam temperature control process, the first regulator outputs a post-water spraying temperature set value based on the superheated steam temperature measurement value and the post-water spraying temperature measurement value.

[0123] S103. The second regulator outputs the cooling water valve control value at the current moment according to the temperature measurement value after water spraying and the cooling water valve control value at the previous moment.

[0124] In combination with step S102 and step S103, in this solution, the delay time is determined according to the load value of the unit and the preset function F(X), and a delay on-off is set based on the calculation result of the fourth logic value according to the delay time;

[0125] When the fourth logic value is 1 and the delay time has elapsed, the tracking / holding signal acts on the main regulator (first regulator) and the auxiliary regulator (second regulator) respectively;

[0126] After receiving the tracking / holding signal, the main regulator outputs the post-water spraying temperature set value according to the superheated steam temperature measurement value and the post-water spraying temperature measurement value;

[0127] After receiving the tracking / holding signal, the sub-regulator outputs the current cooling water valve control value (cooling water valve instruction) based on the temperature measurement value after water spraying and the cooling water valve control value at the previous moment.

[0128] S104. When integral saturation does not occur during the superheated steam temperature control process, the first regulator outputs a post-water spraying temperature setting value based on the superheated steam temperature measurement value and the superheated steam temperature setting value.

[0129] S105. The second regulator outputs the cooling water valve control value according to the temperature measurement value after water spraying and the temperature setting value after water spraying.

[0130] In combination with step S104 and step S105, when the tracking / holding signal is not generated, the main regulator outputs the post-water spraying temperature setting value according to the superheated steam temperature measurement value and the superheated steam temperature setting value;

[0131] The auxiliary regulator outputs the control value of the cooling water valve according to the measured value of the temperature after water spraying and the set value of the temperature after water spraying (output by the main regulator).

[0132] In this scheme, according to the operating characteristics of the superheater cooling water valve, by analyzing the historical curve method, the limit value of the sub-regulator inlet deviation when the superheater cooling water system occurs integral saturation can be determined, and by setting the cooling water valve instruction (cooling water valve value) corresponding to the sub-regulator inlet deviation limit function, some exceptional situations can be handled, such as poor cooling water valve flow characteristics, too much idle stroke and other problems.

[0133] In this scheme, the logic design is relatively simple and clear, the principle is clear and easy to understand, and it can be easily implemented in any DCS system; the parameter setting of this logic design is relatively simple, and it only needs to adjust the inlet deviation limit of the sub-regulator according to the actual operation of the cooling water valve; this logic design determines whether there is integral saturation in the superheater cooling water regulation by judging the inlet deviation of the superheater cooling water sub-regulator and the level of the superheater cooling water control valve instruction and the rise or fall of the superheater temperature measurement value. At the same time, under the integral saturation situation, the inlet deviation of the superheater cooling water main regulator and the sub-regulator is cleverly handled, which can effectively suppress the integral saturation of the superheater cooling water regulator and optimize the control process of the superheater cooling water.

[0134] Embodiment 2

[0135] This embodiment provides a steam temperature control device, including a steam temperature control unit, which is used to:

[0136] Determine whether integral saturation occurs during the superheated steam temperature control process according to the measured value of the temperature after water spraying, the set value of the temperature after water spraying, the measured value of the superheated steam temperature and the control value of the desuperheating water valve;

[0137] When integral saturation occurs during the superheated steam temperature control process, the first regulator outputs a post-water spraying temperature set value according to the superheated steam temperature measurement value and the post-water spraying temperature measurement value;

[0138] The second regulator outputs the control value of the cooling water valve at the current moment according to the temperature measurement value after water spraying and the control value of the cooling water valve at the previous moment;

[0139] When integral saturation does not occur during the superheated steam temperature control process, the first regulator outputs a post-water spraying temperature setting value according to the superheated steam temperature measurement value and the superheated steam temperature setting value;

[0140] The second regulator outputs the control value of the cooling water valve according to the measured value of the temperature after water spraying and the set value of the temperature after water spraying.

[0141] Exemplarily, in this embodiment, the steam temperature control unit can be configured to implement any one of the steam temperature control methods recorded in Example 1. The implementation process and beneficial effects of the method are the same as the corresponding contents recorded in Example 1, and the specific contents will not be described in detail.

[0142] Embodiment 3

[0143] Figure 5 A schematic diagram of the structure of an electronic device 10 that can be used to implement an embodiment of the present invention is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or required herein.

[0144] like Figure 5 As shown, the electronic device 10 includes at least one processor 11, and a memory connected to the at least one processor 11, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc., wherein the memory stores a computer program that can be executed by at least one processor, and the processor 11 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 12 or the computer program loaded from the storage unit 18 to the random access memory (RAM) 13. In the RAM 13, various programs and data required for the operation of the electronic device 10 can also be stored. The processor 11, the ROM 12, and the RAM 13 are connected to each other through a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0145] A number of components in the electronic device 10 are connected to the I / O interface 15, including: an input unit 16, such as a keyboard, a mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a disk, an optical disk, etc.; and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the electronic device 10 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0146] The processor 11 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The processor 11 performs the various methods and processes described above, such as the steam temperature control method.

[0147] In some embodiments, the steam temperature control method may be implemented as a computer program, which is tangibly contained in a computer-readable storage medium, such as a storage unit 18. In some embodiments, part or all of the computer program may be loaded and / or installed on the electronic device 10 via the ROM 12 and / or the communication unit 19. When the computer program is loaded into the RAM 13 and executed by the processor 11, one or more steps of the steam temperature control method described above may be performed. Alternatively, in other embodiments, the processor 11 may be configured to perform the steam temperature control method in any other appropriate manner (e.g., by means of firmware).

[0148] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0149] Computer programs for implementing the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that when the computer program is executed by the processor, the functions / operations specified in the flow chart and / or block diagram are implemented. The computer program may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0150] In the context of the present invention, a computer-readable storage medium may be a tangible medium that may contain or store a computer program for use by or in combination with an instruction execution system, device or equipment. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices or equipment, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0151] To provide interaction with a user, the systems and techniques described herein may be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or trackball) through which the user can provide input to the electronic device. Other types of devices may also be used to provide interaction with the user; for example, the feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user may be received in any form (including acoustic input, voice input, or tactile input).

[0152] The systems and techniques described herein may be implemented in a computing system that includes backend components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes frontend components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such backend components, middleware components, or frontend components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0153] A computing system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The client and server relationship is generated by computer programs running on the corresponding computers and having a client-server relationship with each other. The server may be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system to solve the defects of difficult management and weak business scalability in traditional physical hosts and VPS services.

[0154] Embodiment 4

[0155] This embodiment provides a computer program product, including a computer program. When the computer program is executed by a processor, it implements any one of the steam temperature control methods recorded in the embodiments of the present invention. The steam temperature control method and beneficial effects are the same as the corresponding contents recorded in Example 1, and will not be repeated here.

[0156] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A steam temperature control method, characterized in that: include: Determine whether integral saturation occurs during the superheated steam temperature control process according to the measured value of the temperature after water spraying, the set value of the temperature after water spraying, the measured value of the superheated steam temperature and the control value of the desuperheating water valve; When integral saturation occurs during the superheated steam temperature control process, the first regulator outputs a post-water spraying temperature set value according to the superheated steam temperature measurement value and the post-water spraying temperature measurement value; The second regulator outputs the control value of the cooling water valve at the current moment according to the temperature measurement value after water spraying and the control value of the cooling water valve at the previous moment; When integral saturation does not occur during the superheated steam temperature control process, the first regulator outputs a post-water spraying temperature setting value according to the superheated steam temperature measurement value and the superheated steam temperature setting value; The second regulator outputs a control value of the cooling water valve according to a measured value of the temperature after water spraying and a set value of the temperature after water spraying.

2. The steam temperature control method according to claim 1, characterized in that: Determine a first logic value according to a measured value of the temperature after water spraying and a set value of the temperature after water spraying; determining a second logic value based on the superheated steam temperature measurement value; Determining a third logic value according to the temperature reducing water valve control value; A fourth logic value is determined according to the first logic value, the second logic value and the third logic value. If the fourth logic value is 1, it is determined that integral saturation occurs; if the fourth logic value is 0, it is determined that integral saturation does not occur.

3. The steam temperature control method according to claim 1, characterized in that: It also includes determining the delay time according to the load value of the unit; The delay time is used when the integral saturation occurs. After the delay time, the first regulator outputs the post-water spraying temperature setting value according to the superheated steam temperature measurement value and the post-water spraying temperature measurement value; The second regulator outputs the control value of the cooling water valve at the current moment according to the temperature measurement value after the water spraying and the control value of the cooling water valve at the previous moment.

4. The steam temperature control method according to claim 3, characterized in that: It also includes determining the delay time using a first function according to the load value of the unit when the unit is in a steady state; When the unit is in dynamic state, the delay time is determined by using a second function according to the load value of the unit.

5. The steam temperature control method according to claim 2, characterized in that: Determine the difference between the measured value of the temperature after water spraying and the set value of the temperature after water spraying, if the difference is greater than a first threshold value, the first logic value is 1, otherwise it is 0; If the superheated steam temperature measurement value is greater than a second threshold value, the second logic value is 1, otherwise it is 0; If the temperature-reducing water valve control value is greater than the third threshold, the third logic value is 1, otherwise it is 0.

6. The steam temperature control method according to any one of claims 1 to 5, characterized in that: The steam temperature control method is used for controlling the temperature of superheated steam in a boiler.

7. A steam temperature control device, characterized in that: A steam temperature control unit is included, wherein the steam temperature control unit is used to: Determine whether integral saturation occurs during the superheated steam temperature control process according to the measured value of the temperature after water spraying, the set value of the temperature after water spraying, the measured value of the superheated steam temperature and the control value of the desuperheating water valve; When integral saturation occurs during the superheated steam temperature control process, the first regulator outputs a post-water spraying temperature set value according to the superheated steam temperature measurement value and the post-water spraying temperature measurement value; The second regulator outputs the control value of the cooling water valve at the current moment according to the temperature measurement value after water spraying and the control value of the cooling water valve at the previous moment; When integral saturation does not occur during the superheated steam temperature control process, the first regulator outputs a post-water spraying temperature setting value according to the superheated steam temperature measurement value and the superheated steam temperature setting value; The second regulator outputs a control value of the cooling water valve according to a measured value of the temperature after water spraying and a set value of the temperature after water spraying.

8. An electronic device, characterized in that: comprising at least one processor, and a memory communicatively connected to the at least one processor; The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the steam temperature control method according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the steam temperature control method according to any one of claims 1 to 6 when executed.

10. A computer program product, characterized in that The invention comprises a computer program, which, when executed by a processor, implements the steam temperature control method according to any one of claims 1 to 6.

Images