Setting value follow-up control method and system for limiting temperature change rate

Abstract

The invention discloses a set value follow-up control method and system for limiting the temperature change rate, and belongs to the field of intelligent control of generator sets. The system comprises a first fuel gas temperature module, a first fuel gas temperature setting module, a second fuel gas temperature setting module, a first deviation fixed value module, a second deviation fixed value module, a set value rising speed limiting module, a set value falling speed limiting module, a constant 0 module, a first subtraction block, a second subtraction block, a first comparison block, a second comparison block, a first switching block and a second switching block. The device comprises a first switching block, a second switching block, a third switching block, a fourth switching block, a speed limiting block, an amplitude limiting block, a gas source switching module and a gas temperature control adjusting valve manual position module. According to the set value follow-up control method for limiting the temperature change rate, the actual operation parameter is compared with the preset target value, and whether the current temperature change rate is within the safety range or not is judged. And if the range is exceeded, the control system takes corresponding measures for adjustment.

Description

Technical Field

[0001] The invention belongs to the field of intelligent control of generator sets, and in particular relates to a set value follow-up control method and system for limiting the temperature change rate. Background Art

[0002] After the gas turbine unit is started, the waste heat boiler quickly increases temperature and pressure. In order to further improve the efficiency of the gas turbine unit, the gas supply characteristics are required to increase the gas turbine inlet temperature.

[0003] Generally, the preheated medium-pressure feed water is used to heat the gas turbine intake temperature. This device is also called FGH (fuel gasheating) circuit. The FGH circuit is equipped with a return water regulating valve to control the gas turbine intake temperature by controlling the opening of the return water.

[0004] The gas temperature control effect is limited by factors such as medium-pressure feed water temperature and gas temperature control valve opening. Because the pipeline is long and the gas temperature is controlled by indirect heat exchange, there is a large lag in this control, making it difficult to achieve precise control. Gas turbine units are mostly open-loop controlled with pre-fabricated opening or full opening.

[0005] When the FGH regulating valve fluctuates greatly, the FGH flow rate will fluctuate greatly synchronously, which will cause disturbance of the waste heat boiler drum water level and even affect the safe operation of the unit. Summary of the invention

[0006] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a set value follow-up control method and system for limiting the temperature change rate, which can gradually increase or decrease the gas temperature at a pre-set rate to meet the unit's demand for gas temperature.

[0007] In order to achieve the above object, the present invention adopts the following technical solution: A set value follow-up control system for limiting the temperature change rate, comprising a first gas temperature module, a first gas temperature setting module, a second gas temperature setting module, a first deviation fixed value module, a second deviation fixed value module, a set value increase speed limit module, a set value decrease speed limit module, a constant 0 module, a first subtraction block, a second subtraction block, a first comparison block, a second comparison block, a first switching block, a second switching block, a third switching block, a fourth switching block, a speed limit block, a limit block, a gas source switching module and a gas temperature control valve manual position module; The output end OUT of the speed limit block is connected to the input end X1 of the first subtraction block, the output end of the first gas temperature module is connected to the input end X2 of the first subtraction block, the output end OUT of the first subtraction block is connected to the input end X1 of the first comparison block, the output end of the first deviation setting module is connected to the input end X2 of the first comparison block, the output end OUT of the first comparison block is connected to the input end T of the first switching block, the output end of the set value increase speed limit module is connected to the input end N of the first switching block, and the output end of the constant 0 module is connected to the input end Y of the first switching block; The output end OUT of the speed limit block is connected to the input end X1 of the second subtraction block, the output end of the first gas temperature module is connected to the input end X2 of the second subtraction block, the output end OUT of the second subtraction block is connected to the input end X1 of the second comparison block, the output end of the second deviation setting module is connected to the input end X2 of the second comparison block, the output end OUT of the second comparison block is connected to the input end T of the second switching block, the output end of the set value reduction speed limit module is connected to the input end N of the second switching block, and the output end of the constant 0 module is connected to the input end Y of the second switching block; The output end of the gas source switching module is connected to the input end T of the third switching block, the output end of the first gas temperature setting module is connected to the input end Y of the third switching block, the output end of the second gas temperature setting module is connected to the input end N of the third switching block, the output end of the gas temperature control valve manual position module is connected to the input end T of the fourth switching block, the output end of the first gas temperature module is connected to the input end Y of the fourth switching block, and the output end OUT of the third switching block is connected to the input end N of the fourth switching block; The output end OUT of the first switching block is connected to the input end X1 of the speed limit block, the output end OUT of the second switching block is connected to the input end X2 of the speed limit block, the output end OUT of the fourth switching block is connected to the input end X0 of the speed limit block, the output end of the gas temperature control valve manual position module is connected to the input end X3 of the speed limit block, and the output end OUT of the speed limit block is connected to the input end X1 of the amplitude limiting block.

[0008] A further improvement of the present invention is that it also includes a second gas temperature module, a gas temperature rise rate upper limit, a gas temperature drop rate upper limit, a first filter block, a second filter block, a third subtraction block, a fourth subtraction block, a third comparison block, a fourth comparison block, a PID control block, a device operation block and a gas temperature control valve instruction block; The output end of the second gas temperature module is connected to the input end X1 of the third subtraction block, the output end of the second gas temperature module is connected to the input end X1 of the first filter block, and the output end OUT of the first filter block is connected to the input end X2 of the third subtraction block; the output end OUT of the third subtraction block is connected to the input end X1 of the third comparison block, and the output end of the upper limit of the gas temperature rise rate is connected to the input end X2 of the third comparison block; The output end of the second gas temperature module is connected to the input end X1 of the fourth subtraction block, the output end of the second gas temperature module is connected to the input end X1 of the second filter block, and the output end OUT of the second filter block is connected to the input end X2 of the fourth subtraction block; the output end OUT of the fourth subtraction block is connected to the input end X1 of the fourth comparison block, and the output end of the upper limit of the gas temperature drop rate is connected to the input end X2 of the fourth comparison block; The output end of the second gas temperature module is connected to the input end X1 of the PID control block, the output end OUT of the limiter block is connected to the input end X2 of the PID control block, the output end OUT of the third comparison block is connected to the input end X3 of the PID control block, the output end OUT of the fourth comparison block is connected to the input end X4 of the PID control block, the output end OUT of the PID control block is connected to the input end X1 of the equipment operation block, and the output end OUT of the equipment operation block is connected to the input end of the gas temperature control valve instruction block.

[0009] A further improvement of the present invention is that when the X3 pin of the speed limit block is a true value, the output is unlimited speed, otherwise limited speed; X0 is the input value, when the rising rate exceeds the rising speed limit, the output is the value after the speed limit, otherwise the output is the X0 value; when the falling rate exceeds the falling speed limit, the output is the value after the speed limit, otherwise the output is the X0 value.

[0010] A further improvement of the present invention is that, in the limit block, the input value X0 is limited to a range of L to H limits.

[0011] A further improvement of the present invention is that the constant 0 module defaults to 0, and when the control deviation is greater than 30, the PID adjustment set value change is suspended.

[0012] A set value follow-up control method for limiting the temperature change rate, based on the set value follow-up control system for limiting the temperature change rate, comprises: The output end of the speed limit block is subtracted from the first gas temperature module by the first subtraction block, and the obtained value is compared with the first deviation setting module by the first comparison block for greater than, and the obtained value is the output end of the first comparison block. When it is 0, the set value of the "N" end of the first switching block is output to increase the speed limit module, and when it is 1, the constant 0 module of the "Y" end of the first switching block is output; the output end of the speed limit block is subtracted from the first gas temperature module by the second subtraction block, and the obtained value is compared with the second deviation setting module by the second comparison block for less than, and the obtained value is the output end of the second comparison block. When it is 0, the set value of the "N" end of the second switching block is output to decrease the speed limit module, and when it is 1, the constant 0 module of the "Y" end of the second switching block is output; when the gas source switching module is 0, the second gas temperature at the "N" end of the third switching block is output. When the gas source switching module is 1, the first gas temperature setting module at the "Y" end of the third switching block is output; when the gas temperature control valve manual position module is 0, the third switching block output value at the "N" end of the fourth switching block is output, and when the gas temperature control valve manual position module is 1, the first gas temperature module at the "Y" end of the fourth switching block is output; the output end of the first switching block, the output end of the second switching block, the output end of the fourth switching block, and the gas temperature control valve manual position module act on the "X1", "X2", "X0", and "X3" ends of the speed limit block respectively, X0 is the input value, X1 is the increase rate, X2 is the decrease rate, and X3 is the speed limit trigger end. When X3=1, there is no speed limit, and when X3=0, the output end value of the speed limit block is output; the output end of the speed limit block acts on the limit block to obtain the final value after limit.

[0013] A further improvement of the present invention is that it also includes: The value of the second gas temperature module calculated by the first filter block is subtracted from the value of the second gas temperature module by the third subtraction block, and the value of the output end of the third subtraction block is compared with the upper limit of the gas temperature rise rate by the third comparison block; the value of the second gas temperature module calculated by the second filter block is subtracted from the value of the second gas temperature module by the fourth subtraction block, and the value of the output end of the fourth subtraction block is compared with the upper limit of the gas temperature drop rate by the fourth comparison block; the output ends of the second gas temperature module, the limiter block, the third comparison block, and the fourth comparison block are respectively applied to the "X1", "X2", "X3", and "X4" ends of the PID control block, and the value obtained after calculation by the PID control block is judged by the equipment operation block, and the gas temperature control valve instruction block is finally output.

[0014] A further improvement of the present invention is that when the X3 pin of the speed limit block is a true value, the output is unlimited speed, otherwise limited speed; X0 is the input value, when the rising rate exceeds the rising speed limit, the output is the value after the speed limit, otherwise the output is the X0 value; when the falling rate exceeds the falling speed limit, the output is the value after the speed limit, otherwise the output is the X0 value.

[0015] A further improvement of the present invention is that, in the limit block, the input value X0 is limited to a range of L to H limits.

[0016] A further improvement of the present invention is that the constant 0 module defaults to 0, and when the control deviation is greater than 30, the PID adjustment set value change is suspended.

[0017] Compared with the prior art, the present invention has at least the following beneficial technical effects: The set value follow-up control system for limiting the temperature change rate provided by the present invention is an automatic control method in which the output of the controlled device (such as temperature, pressure, etc.) is automatically adjusted following the change of the input signal to maintain the stability and balance of the system. In the follow-up control of limiting the temperature change rate of the gas unit, the control system will dynamically adjust the temperature change rate according to the actual operating state and environmental conditions of the unit to keep it within a safe and stable range.

[0018] The set value follow-up control method for limiting the temperature change rate provided by the present invention compares the actual operating parameters with the preset target value to determine whether the current temperature change rate is within a safe range. If it is beyond the range, the control system will take corresponding measures to make adjustments.

[0019] Furthermore, according to different gas sources, the automatic control adapts to the optimal gas temperature. When the PID control set value deviates greatly from the actual value, the PID control set value is automatically limited to increase or decrease to wait for the slow change of the PID control actual value. Because the PID control deviation is limited, the gas temperature control valve is controlled more slowly, and the disturbance to the water supply of the waste heat boiler is small. The PID control set value is limited to a reasonable range to prevent the gas temperature from deviating from the control due to setting errors during operation. Automatically control the gas temperature within a reasonable temperature rise / fall range. When the gas temperature rise rate is too fast, the gas temperature control valve control automatically prohibits the increase; when the gas temperature drop rate is too fast, the gas temperature control valve control automatically prohibits the decrease; to adapt to the safe operation of the unit.

[0020] In summary, the set value follow-up control method for limiting the temperature change rate described in the present invention limits the increase / decrease of the PID set value through the PID control deviation; and limits the increase / decrease of the PID output through the temperature rise / fall rate of the gas turbine. The gas temperature can be automatically controlled, reducing the influence of the large lag of the FGH system on the control accuracy; the gas temperature control is accurate, the unit is safer and more reliable; the gas temperature control is stable, and the disturbance to the water level of the waste heat boiler drum is smaller. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 System diagram of a set point follow-up control system that limits the rate of temperature change.

[0023] Figure 2 A control loop for a set point follow-up control system that limits the rate of temperature change.

[0024] Figure 3 The diagram is an implementation effect diagram of a set value follow-up control method and system for limiting the temperature change rate.

[0025] Description of reference numerals: First gas temperature module AI-01, first gas temperature setting module AI-02, second gas temperature setting module AI-03, first deviation setting module AI-04, second deviation setting module AI-05, set value increase speed limit module AI-06, set value decrease speed limit module AI-07, constant 0 module AI-08, first subtraction block SUB-01, second subtraction block SUB-02, first comparison block H-01, second comparison block L-01, first switching block T-01, second switching block T-02, third switching block T-03, fourth switching block T-04, speed limit block V-01, amplitude limit block LIM-01, gas source switching module DI-01, gas temperature control valve manual position module DI-02; The second gas temperature module AI-09, the upper limit of the gas temperature rise rate AI-10, the upper limit of the gas temperature drop rate AI-11, the first filter block LAG-01, the second filter block LAG-02, the third subtraction block SUB-03, the fourth subtraction block SUB-04, the third comparison block H-02, the fourth comparison block L-02, the PID control block PID-01, the equipment operation block MA-01, and the gas temperature control valve instruction block AO-01. DETAILED DESCRIPTION

[0026] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0027] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0028] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0029] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0031] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0032] It should be further understood that the term "and / or" used in the present description and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0033] Various structural schematic diagrams of the embodiments disclosed in the present invention are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0034] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0035] The implementation of the present invention in different DCS, PLC and other control systems has different forms due to different computer languages, but the implementation method and function remain unchanged. The relevant parameter settings should be set according to the actual operating parameters of the unit.

[0036] Example 1 1) Figure 1 System diagram of a set point follow-up control system with limited temperature change rate.

[0037] It specifically includes: low-pressure steam drum 001, feed water pump A002, feed water pump B003, gas cooling air 004, gas hot air 005, FGH006, gas temperature control regulating valve 007, and gas temperature control regulating valve return water 008.

[0038] The process flow specifically includes: the low-pressure drum 001 is connected to the feedwater pump A002 and feedwater pump B003 respectively, the gas cold air 004 acts on FGH006, and FGH006 can output gas hot air 005 after the action, and is then connected to the gas temperature control valve 007 and the gas temperature control valve return water 008 in sequence. The principle is that the FGH hot water is taken from the feedwater pumps A and B, and the gas temperature control valve (installed on the FGH return water side) controls the gas turbine FGH return water flow to further control the gas turbine intake temperature. After the unit is started, the FGH inlet water temperature gradually increases; when certain conditions are met, when the gas temperature control valve is put into automatic control, the gas temperature is transferred to automatic control.

[0039] 2) Figure 2 A control loop for a setpoint follow-up control system that limits the rate of temperature change.

[0040] It specifically includes: the first gas temperature module AI-01, the first gas temperature setting module AI-02, the second gas temperature setting module AI-03, the first deviation constant module AI-04, the second deviation constant module AI-05, the set value increase speed limit module AI-06, the set value decrease speed limit module AI-07, the constant 0 module AI-08, the first subtraction block SUB-01, the second subtraction block SUB-02, the first comparison block H-01, the second comparison block L-01, the first switching block T-01, the second switching block T-02, the third switching block T-03, the fourth switching block T-04, the speed limit block V-01, the limit block LIM-01, the gas source switching module DI-01, and the gas temperature control valve manual position module DI-02.

[0041] The control strategy logic diagram includes: (1) The output end OUT of the speed limit block V-01 is connected to the input end X1 of the first subtraction block SUB-01, the output end of the first gas temperature module AI-01 is connected to the input end X2 of the first subtraction block SUB-01, the output end OUT of the first subtraction block SUB-01 is connected to the input end X1 of the first comparison block H-01, the output end of the first deviation setting module AI-04 is connected to the input end X2 of the first comparison block H-01, the output end OUT of the first comparison block H-01 is connected to the input end T of the first switching block T-01, the output end of the set value increase speed limit module AI-06 is connected to the input end N of the first switching block T-01, and the output end of the constant 0 module AI-08 is connected to the input end Y of the first switching block T-01.

[0042] (2) The output end OUT of the speed limit block V-01 is connected to the input end X1 of the second subtraction block SUB-02, the output end of the first gas temperature module AI-01 is connected to the input end X2 of the second subtraction block SUB-02, the output end OUT of the second subtraction block SUB-02 is connected to the input end X1 of the second comparison block L-01, the output end of the second deviation setting module AI-05 is connected to the input end X2 of the second comparison block L-01, the output end OUT of the second comparison block L-01 is connected to the input end T of the second switching block T-02, the output end of the set value reduction speed limit module AI-07 is connected to the input end N of the second switching block T-02, and the output end of the constant 0 module AI-08 is connected to the input end Y of the second switching block T-02.

[0043] (3) The output end of the gas source switching module DI-01 is connected to the input end T of the third switching block T-03, the output end of the first gas temperature setting module AI-02 is connected to the input end Y of the third switching block T-03, the output end of the second gas temperature setting module AI-03 is connected to the input end N of the third switching block T-03, the output end of the gas temperature control valve manual position module DI-02 is connected to the input end T of the fourth switching block T-04, the output end of the first gas temperature module AI-01 is connected to the input end Y of the fourth switching block T-04, and the output end OUT of the third switching block T-03 is connected to the input end N of the fourth switching block T-04.

[0044] (4) The output end OUT of the first switching block T-01 is connected to the input end X1 of the speed limit block V-01, the output end OUT of the second switching block T-02 is connected to the input end X2 of the speed limit block V-01, the output end OUT of the fourth switching block T-04 is connected to the input end X0 of the speed limit block V-01, the output end of the gas temperature control valve manual position module DI-02 is connected to the input end X3 of the speed limit block V-01, and the output end OUT of the speed limit block V-01 is connected to the input end X1 of the amplitude limiting block LIM-01.

[0045] (5) The gas temperature control circuit includes: the second gas temperature module AI-09, the gas temperature rise rate upper limit AI-10, the gas temperature drop rate upper limit AI-11, the first filter block LAG-01, the second filter block LAG-02, the third subtraction block SUB-03, the fourth subtraction block SUB-04, the third comparison block H-02, the fourth comparison block L-02, the PID control block PID-01, the equipment operation block MA-01, and the gas temperature control valve instruction block AO-01.

[0046] (6) The output end of the second gas temperature module AI-09 is connected to the input end X1 of the third subtraction block SUB-03, the output end of the second gas temperature module AI-09 is connected to the input end X1 of the first filter block LAG-01, the output end OUT of the first filter block LAG-01 is connected to the input end X2 of the third subtraction block SUB-03; the output end OUT of the third subtraction block SUB-03 is connected to the input end X1 of the third comparison block H-02, and the output end of the gas temperature rise rate upper limit AI-10 is connected to the input end X2 of the third comparison block H-02.

[0047] (7) The output end of the second gas temperature module AI-09 is connected to the input end X1 of the fourth subtraction block SUB-04, the output end of the second gas temperature module AI-09 is connected to the input end X1 of the second filter block LAG-02, the output end OUT of the second filter block LAG-02 is connected to the input end X2 of the fourth subtraction block SUB-04; the output end OUT of the fourth subtraction block SUB-04 is connected to the input end X1 of the fourth comparison block L-02, and the output end of the gas temperature drop rate upper limit AI-11 is connected to the input end X2 of the fourth comparison block L-02.

[0048] (8) The output end of the second gas temperature module AI-09 is connected to the input end X1 of the PID control block PID-01, the output end OUT of the limiter block LIM-01 is connected to the input end X2 of the PID control block PID-01, the output end OUT of the third comparison block H-02 is connected to the input end X3 of the PID control block PID-01, the output end OUT of the fourth comparison block L-02 is connected to the input end X4 of the PID control block PID-01, the output end OUT of the PID control block PID-01 is connected to the input end X1 of the equipment operation block MA-01, and the output end OUT of the equipment operation block MA-01 is connected to the input end of the gas temperature control valve instruction block AO-01.

[0049] (9) The selection block T includes: a first switching block T-01, a second switching block T-02, a third switching block T-03 and a fourth switching block T-04. When the selection block T is a false value, the selection block outputs the value of the pin N; when the selection block T is a true value, the selection block outputs the value of the pin Y.

[0050] (10) The characteristic of the speed limit block V-01 is that when the X3 pin is true, the output is unlimited speed, otherwise it is limited speed; X0 is the input value, when the rising rate exceeds the rising speed limit, the output is the value after the speed limit, otherwise it is the value of X0; when the falling rate exceeds the falling speed limit, the output is the value after the speed limit, otherwise it is the value of X0.

[0051] (11) The feature of the limit block LIM-01 is to limit the input value X0 to a reasonable range (within the L limit to H limit range).

[0052] (12) The setting values ​​of the constant setting blocks (first gas temperature setting module AI-02, second gas temperature setting module AI-03, first deviation setting module AI-04, second deviation setting module AI-05, set value increase speed limit module AI-06, set value decrease speed limit module AI-07, gas temperature rise rate upper limit AI-10, gas temperature drop rate upper limit AI-11) shall be determined according to the on-site conditions to meet the on-site control requirements.

[0053] (13) Constant 0 module AI-08 defaults to 0. When the control deviation is large, the PID adjustment set value change is suspended to meet the needs of large lag control.

[0054] (14) The time parameter setting values ​​of the filter blocks (first filter block LAG-01, second filter block LAG-02) are determined according to the on-site conditions to meet the on-site control requirements.

[0055] Example 2 like Figure 2 As shown, the set value follow-up control method for limiting the temperature change rate provided by the present invention includes: The output end of the speed limit block V-01 is subtracted from the first gas temperature module AI-01 by the first subtraction block SUB-01, and the obtained value is compared with the first deviation constant module AI-04 by the first comparison block H-01. The obtained value is the output end of the first comparison block H-01. When it is 0, it outputs the set value of the "N" end of the first switching block T-01 to the speed limit module AI-06. When it is 1, it outputs the constant 0 module AI-08 at the "Y" end of the first switching block T-01; the output end of the speed limit block V-01 is compared with the first deviation constant module AI-04 by the first comparison block H-01. The gas temperature module AI-01 uses the second subtraction block SUB-02 for subtraction operation, and the obtained value is compared with the second deviation constant module AI-05 using the second comparison block L-01 for less than, and the obtained value is the output end of the second comparison block L-01. When it is 0, it outputs the set value of the "N" end of the second switching block T-02. The speed reduction module AI-07, when it is 1, outputs the constant 0 module AI-08 of the "Y" end of the second switching block T-02; when the gas source switching module DI-01 is 0, it outputs the set value of the third switching block T-03. The second gas temperature setting module AI-03 at the "N" end, when the gas source switching module DI-01 is 1, outputs the first gas temperature setting module AI-02 at the "Y" end of the third switching block T-03; when the gas temperature control valve manual position module DI-02 is 0, outputs the output end value of the third switching block T-03 at the "N" end of the fourth switching block T-04, and when the gas temperature control valve manual position module DI-02 is 1, outputs the first gas temperature module AI-01 at the "Y" end of the fourth switching block T-04; the first switching block T-01 The output end, the output end of the second switching block T-02, the output end of the fourth switching block T-04, and the gas temperature control valve manual position module DI-02 act on the "X1", "X2", "X0", and "X3" ends of the speed limit block V-01 respectively, where X0 is the input value, X1 is the increase rate, X2 is the decrease rate, and X3 is the speed limit trigger end. When X3=1, there is no speed limit, and when X3=0, the output end value of the speed limit block V-01 is output; the output end of the speed limit block V-01 acts on the limiter block LIM-01 to obtain the final value after limiting.

[0056] In this embodiment, it also includes: The value of the second gas temperature module AI-09 calculated by the first filter block LAG-01 is subtracted from the second gas temperature module AI-09 by the third subtraction block SUB-03, and the value obtained at the output of the third subtraction block SUB-03 is compared with the upper limit of the gas temperature rise rate AI-10 by the third comparison block H-02; the value of the second gas temperature module AI-09 calculated by the second filter block LAG-02 is subtracted from the second gas temperature module AI-09 by the fourth subtraction block SUB-04, and the output of the fourth subtraction block SUB-04 is compared with the upper limit of the gas temperature rise rate AI-10 by the third comparison block H-02; The value at the output end is compared with the upper limit AI-11 of the gas temperature drop rate by the fourth comparison block L-02; the output end of the second gas temperature module AI-09, the limiter block LIM-01, the output end of the third comparison block H-02, and the output end of the fourth comparison block L-02 are respectively applied to the "X1", "X2", "X3", and "X4" ends of the PID control block PID-01. The value obtained after calculation by the PID control block PID-01 is judged by the equipment operation block MA-01, and the final output end obtains the gas temperature control valve instruction block AO-01.

[0057] Example 3 like Figure 3 As shown, through the present invention, during the operation of the gas unit, after the gas temperature control valve is automatically put into operation from a certain set time, the gas temperature setting value presents a curve of gradually climbing steps according to the follow-up control method. The control at this stage is stable and safe to adapt to the operating conditions of large lag in gas temperature control. The gas temperature control valve is limited within the pre-set heating rate, so the gas temperature control valve instruction presents a trend of gentle change, avoiding adverse conditions such as sudden rise and fall of valve position control, and ensuring the effect of stable and safe control. The gas temperature can be automatically controlled, reducing the influence of large lag of the FGH system on the control accuracy, and providing flexibility and high efficiency of the gas unit.

[0058] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0059] In addition, it should be understood that although this specification is described in accordance with the implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation modes that can be understood by those skilled in the art. The above content is only to illustrate the technical idea of ​​the present invention, and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A set value follow-up control system for limiting the temperature change rate, characterized in that: It includes a first gas temperature module, a first gas temperature setting module, a second gas temperature setting module, a first deviation setting module, a second deviation setting module, a set value increase speed limit module, a set value decrease speed limit module, a constant 0 module, a first subtraction block, a second subtraction block, a first comparison block, a second comparison block, a first switching block, a second switching block, a third switching block, a fourth switching block, a speed limit block, a limit block, a gas source switching module and a gas temperature control valve manual position module; The output end OUT of the speed limit block is connected to the input end X1 of the first subtraction block, the output end of the first gas temperature module is connected to the input end X2 of the first subtraction block, the output end OUT of the first subtraction block is connected to the input end X1 of the first comparison block, the output end of the first deviation setting module is connected to the input end X2 of the first comparison block, the output end OUT of the first comparison block is connected to the input end T of the first switching block, the output end of the set value increase speed limit module is connected to the input end N of the first switching block, and the output end of the constant 0 module is connected to the input end Y of the first switching block; The output end OUT of the speed limit block is connected to the input end X1 of the second subtraction block, the output end of the first gas temperature module is connected to the input end X2 of the second subtraction block, the output end OUT of the second subtraction block is connected to the input end X1 of the second comparison block, the output end of the second deviation setting module is connected to the input end X2 of the second comparison block, the output end OUT of the second comparison block is connected to the input end T of the second switching block, the output end of the set value reduction speed limit module is connected to the input end N of the second switching block, and the output end of the constant 0 module is connected to the input end Y of the second switching block; The output end of the gas source switching module is connected to the input end T of the third switching block, the output end of the first gas temperature setting module is connected to the input end Y of the third switching block, the output end of the second gas temperature setting module is connected to the input end N of the third switching block, the output end of the gas temperature control valve manual position module is connected to the input end T of the fourth switching block, the output end of the first gas temperature module is connected to the input end Y of the fourth switching block, and the output end OUT of the third switching block is connected to the input end N of the fourth switching block; The output end OUT of the first switching block is connected to the input end X1 of the speed limit block, the output end OUT of the second switching block is connected to the input end X2 of the speed limit block, the output end OUT of the fourth switching block is connected to the input end X0 of the speed limit block, the output end of the gas temperature control valve manual position module is connected to the input end X3 of the speed limit block, and the output end OUT of the speed limit block is connected to the input end X1 of the amplitude limiting block.

2. The set value follow-up control system for limiting the temperature change rate according to claim 1, characterized in that: It also includes a second gas temperature module, a gas temperature rise rate upper limit, a gas temperature drop rate upper limit, a first filter block, a second filter block, a third subtraction block, a fourth subtraction block, a third comparison block, a fourth comparison block, a PID control block, a device operation block and a gas temperature control valve instruction block; The output end of the second gas temperature module is connected to the input end X1 of the third subtraction block, the output end of the second gas temperature module is connected to the input end X1 of the first filter block, and the output end OUT of the first filter block is connected to the input end X2 of the third subtraction block; the output end OUT of the third subtraction block is connected to the input end X1 of the third comparison block, and the output end of the upper limit of the gas temperature rise rate is connected to the input end X2 of the third comparison block; The output end of the second gas temperature module is connected to the input end X1 of the fourth subtraction block, the output end of the second gas temperature module is connected to the input end X1 of the second filter block, and the output end OUT of the second filter block is connected to the input end X2 of the fourth subtraction block; the output end OUT of the fourth subtraction block is connected to the input end X1 of the fourth comparison block, and the output end of the upper limit of the gas temperature drop rate is connected to the input end X2 of the fourth comparison block; The output end of the second gas temperature module is connected to the input end X1 of the PID control block, the output end OUT of the limiter block is connected to the input end X2 of the PID control block, the output end OUT of the third comparison block is connected to the input end X3 of the PID control block, the output end OUT of the fourth comparison block is connected to the input end X4 of the PID control block, the output end OUT of the PID control block is connected to the input end X1 of the equipment operation block, and the output end OUT of the equipment operation block is connected to the input end of the gas temperature control valve instruction block.

3. The set value follow-up control system for limiting the temperature change rate according to claim 2, characterized in that: When the X3 pin of the speed limit block is true, the output is no speed limit, otherwise it is speed limited; X0 is the input value. When the rising rate exceeds the rising speed limit, the output is the value after the speed limit, otherwise it outputs the X0 value; when the falling rate exceeds the falling speed limit, the output is the value after the speed limit, otherwise it outputs the X0 value.

4. The set value follow-up control system for limiting the temperature change rate according to claim 2, characterized in that: In the limit block, the input value X0 is limited to the range of L limit to H limit.

5. The set value follow-up control system for limiting the temperature change rate according to claim 2, characterized in that: The constant 0 module defaults to 0. When the control deviation is greater than 30, the PID adjustment set value change is suspended.

6. A set value follow-up control method for limiting the temperature change rate, characterized in that: The method is based on the set value follow-up control system for limiting the temperature change rate as claimed in claim 2, comprising: The output end of the speed limit block is subtracted from the first gas temperature module by the first subtraction block, and the obtained value is compared with the first deviation setting module by the first comparison block for greater than, and the obtained value is the output end of the first comparison block. When it is 0, the set value of the "N" end of the first switching block is output to increase the speed limit module, and when it is 1, the constant 0 module of the "Y" end of the first switching block is output; the output end of the speed limit block is subtracted from the first gas temperature module by the second subtraction block, and the obtained value is compared with the second deviation setting module by the second comparison block for less than, and the obtained value is the output end of the second comparison block. When it is 0, the set value of the "N" end of the second switching block is output to decrease the speed limit module, and when it is 1, the constant 0 module of the "Y" end of the second switching block is output; when the gas source switching module is 0, the second gas temperature at the "N" end of the third switching block is output. When the gas source switching module is 1, the first gas temperature setting module at the "Y" end of the third switching block is output; when the gas temperature control valve manual position module is 0, the third switching block output value at the "N" end of the fourth switching block is output, and when the gas temperature control valve manual position module is 1, the first gas temperature module at the "Y" end of the fourth switching block is output; the output end of the first switching block, the output end of the second switching block, the output end of the fourth switching block, and the gas temperature control valve manual position module act on the "X1", "X2", "X0", and "X3" ends of the speed limit block respectively, X0 is the input value, X1 is the increase rate, X2 is the decrease rate, and X3 is the speed limit trigger end. When X3=1, there is no speed limit, and when X3=0, the output end value of the speed limit block is output; the output end of the speed limit block acts on the limit block to obtain the final value after limit.

7. The set value following control method for limiting the temperature change rate according to claim 6, characterized in that: Also includes: The value of the second gas temperature module calculated by the first filter block is subtracted from the value of the second gas temperature module by the third subtraction block, and the value of the output end of the third subtraction block is compared with the upper limit of the gas temperature rise rate by the third comparison block; the value of the second gas temperature module calculated by the second filter block is subtracted from the value of the second gas temperature module by the fourth subtraction block, and the value of the output end of the fourth subtraction block is compared with the upper limit of the gas temperature drop rate by the fourth comparison block; The output ends of the second gas temperature module, the limiter block, the third comparison block, and the fourth comparison block act on the "X1", "X2", "X3", and "X4" ends of the PID control block respectively. The value obtained after calculation by the PID control block is judged by the equipment operation block, and the final output end obtains the gas temperature control valve instruction block.

8. The set value following control method for limiting the temperature change rate according to claim 6, characterized in that: When the X3 pin of the speed limit block is true, the output is no speed limit, otherwise it is speed limited; X0 is the input value. When the rising rate exceeds the rising speed limit, the output is the value after the speed limit, otherwise it outputs the X0 value; when the falling rate exceeds the falling speed limit, the output is the value after the speed limit, otherwise it outputs the X0 value.

9. The set value following control method for limiting the temperature change rate according to claim 6, characterized in that: In the limit block, the input value X0 is limited to the range of L limit to H limit.

10. The set value follow-up control method for limiting the temperature change rate according to claim 6, characterized in that: The constant 0 module defaults to 0. When the control deviation is greater than 30, the PID adjustment set value change is suspended.

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