Supercritical unit feed water flow wide-load stable control system and method

Abstract

The invention discloses a wide-load stable control system and method for feed water flow of a supercritical unit, and the method comprises the steps: calculating a static feed water flow set value of the supercritical unit based on a load set value of the supercritical unit, and calculating a dynamic feed-forward quantity, a main steam pressure value and a main steam pressure set value based on a fuel quantity; the dynamic feed water flow set value of the supercritical unit is calculated, the total feed water flow set value of the supercritical unit is calculated in combination with the separator temperature correction coefficient, the requirements for stability and quick response can be met at the same time, and a good control effect can be kept under different working conditions and boiler fuel quality changes; and the stability risk caused by a single control strategy is avoided, the method does not depend on manual operation and judgment, and the technical problems that a traditional supercritical unit feed water flow control method is insufficient in response speed, limited in control precision, reduced in stability and insufficient in automation degree in the unit wide load adjusting process are solved.

Description

Technical Field

[0001] The invention relates to the technical field of electric power automation, and in particular to a wide-load stable control system and method for feedwater flow of a supercritical unit. Background Art

[0002] Wide load regulation of thermal power units refers to the ability of thermal power units to achieve efficient and stable operation under different loads through a series of technical means and optimized designs within a wide load range (such as 40%~100% load, or even lower to a load range of stable combustion without oil injection), while minimizing actual energy consumption. This regulation capability is of great significance to improving the flexibility and economy of thermal power units.

[0003] In supercritical units, feedwater flow control is crucial to ensure stable operation of the boiler and improve thermal efficiency. Traditional feedwater flow control methods are mainly divided into two types: feedwater flow control methods based solely on load settings and feedwater flow control methods based solely on boiler master control output. Traditional supercritical unit feedwater flow control methods have the following problems during the unit wide load adjustment process:

[0004] Insufficient response speed: During wide load regulation, due to the large range and rapid speed of load changes, traditional water supply control methods may not be able to respond quickly to such changes, resulting in the regulation of water supply flow lagging behind load demand, affecting the stability and efficiency of the unit.

[0005] Limited control accuracy: Traditional control methods mainly rely on fixed control strategies and parameter settings, which are difficult to adapt to changes in various operating conditions within a wide load range, resulting in large deviations in the control of feed water flow, affecting the boiler's combustion efficiency and steam quality.

[0006] Reduced stability: During the wide load regulation process, the coupling relationship between the various parameters of the unit is complex, and the traditional feedwater flow control method cannot effectively handle this coupling relationship, resulting in reduced system stability. For example, the mismatch between the feedwater flow and the combustion rate may cause fluctuations in the main steam temperature, thereby affecting the safe operation of the unit.

[0007] Insufficient automation: Traditional water flow control methods rely on manual operation and judgment, and have a low degree of automation. In the process of wide load regulation, the lag and uncertainty of manual operation may further increase the difficulty and risk of control.

[0008] In summary, how to solve the technical defects of traditional supercritical unit feed water flow control methods during the wide load regulation of the unit, such as insufficient response speed, limited control accuracy, reduced stability and insufficient automation, is a technical problem that needs to be urgently solved by technical personnel in this field. Summary of the invention

[0009] The present invention provides a wide load stability control system and method for supercritical unit feed water flow, which is used to solve the technical problems of insufficient response speed, limited control accuracy, reduced stability and insufficient automation in the wide load regulation process of the unit in the traditional supercritical unit feed water flow control method.

[0010] In view of this, the first aspect of the present invention provides a supercritical unit feedwater flow wide load stability control system, including a static feedwater flow set value calculation module, a dynamic feedwater flow set value calculation module, a separator outlet temperature correction module and a total feedwater flow set value output module;

[0011] The static feedwater flow rate setting value calculation module is used to calculate the static feedwater flow rate setting value of the supercritical unit according to the load setting value of the supercritical unit, and the static feedwater flow rate is the required feedwater flow rate of the supercritical unit under stable working conditions;

[0012] The dynamic feedwater flow rate setting value calculation module is used to calculate the dynamic feedwater flow rate setting value of the supercritical unit according to the dynamic feedforward amount of the fuel amount, the main steam pressure value and the main steam pressure setting value, wherein the dynamic feedwater flow rate is the additional feedwater flow rate that the supercritical unit needs to increase under variable operating conditions to overcome the boiler combustion inertia and pipeline flow inertia;

[0013] The separator outlet temperature correction module is used to calculate the separator temperature correction coefficient according to the separator outlet temperature value and the separator outlet temperature setting value;

[0014] The total feedwater flow set value output module is used to calculate the total feedwater flow set value of the supercritical unit according to the static feedwater flow set value, the dynamic feedwater flow set value and the separator temperature correction coefficient.

[0015] Optionally, the static water flow rate setting value calculation module includes a load setting submodule, a first function submodule and a first inertia link submodule;

[0016] The load setting submodule is used to obtain the load setting value of the supercritical unit;

[0017] The first function submodule is used to calculate the static feedwater flow setting value of the supercritical unit according to the load setting value of the supercritical unit;

[0018] The first inertia link submodule is used to perform first-order inertia link filtering on the static water feed flow setting value of the supercritical unit.

[0019] Optionally, the dynamic water flow set value calculation module includes a signal acquisition submodule, a second inertia link submodule, a first PID controller submodule, a first summation submodule, a first multiplication submodule and a constant submodule;

[0020] The signal acquisition submodule is used to obtain the dynamic feedforward amount of fuel quantity, the main steam pressure value and the main steam pressure setting value;

[0021] The second inertia link submodule is used to perform filtering processing on the dynamic feedforward amount of the fuel quantity based on the first-order inertia link;

[0022] The first PID controller submodule is used for a first PID correction value of a deviation between the main steam pressure value and the main steam pressure setting value;

[0023] The first summing submodule is used to superimpose the first PID correction amount and the dynamic feedforward amount of the fuel amount output by the second inertia link submodule to obtain a dynamic fuel amount;

[0024] The constant submodule is used to configure the water flow coefficient;

[0025] The first multiplication submodule is used to multiply the dynamic fuel amount by the feed water flow coefficient to obtain the dynamic feed water flow setting value of the supercritical unit.

[0026] Optionally, the preset percentage is 20%.

[0027] Optionally, the separator outlet temperature correction module includes a separator outlet temperature acquisition submodule, a separator outlet temperature setting submodule, a second PID controller submodule and a second function submodule;

[0028] The separator outlet temperature acquisition submodule is used to obtain the separator outlet temperature value;

[0029] The separator outlet temperature setting submodule is used to configure the separator outlet temperature setting value;

[0030] The second PID controller submodule is used to calculate a second PID correction value of the deviation between the separator outlet temperature value and the separator outlet temperature setting value;

[0031] The second function submodule is used to convert the second PID correction value into a separator temperature correction coefficient in the range of 0.8 to 1.2.

[0032] Optionally, the total water flow set value output module includes a second summation submodule and a second multiplication submodule;

[0033] The second summing submodule is used to superimpose and sum the static feedwater flow setting value of the supercritical unit and the dynamic feedwater flow setting value of the supercritical unit to obtain a total feedwater flow;

[0034] The second multiplication submodule is used to multiply the total feed water flow by the separator temperature correction coefficient to obtain a total feed water flow setting value for the supercritical unit.

[0035] Optionally, the dynamic water supply flow set value calculation module also includes an adjustment submodule;

[0036] The adjustment submodule is used to determine whether the proportion of the dynamic water feed flow setting value of the supercritical unit to the total water feed flow setting value of the supercritical unit is less than a preset percentage. If so, no adjustment is made; if not, the dynamic water feed flow setting value of the supercritical unit is adjusted.

[0037] A second aspect of the present invention provides a method for stabilizing feedwater flow rate over a supercritical unit load, the method for stabilizing feedwater flow rate over a supercritical unit load being applied to any one of the supercritical unit feedwater flow rate over a supercritical unit load stabilization control systems provided in the first aspect of the present invention, the method for stabilizing feedwater flow rate over a supercritical unit load comprising:

[0038] Calculating a static feedwater flow setting value of the supercritical unit according to a load setting value of the supercritical unit;

[0039] Calculating a dynamic feedwater flow setting value of the supercritical unit according to a dynamic feedforward amount of fuel, a main steam pressure value and a main steam pressure setting value;

[0040] Calculate the separator temperature correction coefficient according to the separator outlet temperature value and the separator outlet temperature setting value;

[0041] The total feed water flow setting value of the supercritical unit is calculated according to the static feed water flow setting value of the supercritical unit, the dynamic feed water flow setting value of the supercritical unit and the separator temperature correction coefficient.

[0042] Optionally, the total feed water flow setting value of the supercritical unit is calculated according to the static feed water flow setting value of the supercritical unit, the dynamic feed water flow setting value of the supercritical unit and the separator temperature correction coefficient, and then the method further includes:

[0043] Determine whether the proportion of the dynamic water feed flow setting value of the supercritical unit to the total water feed flow setting value of the supercritical unit is less than a preset percentage. If so, do not make any adjustment; if not, adjust the dynamic water feed flow setting value of the supercritical unit.

[0044] Optionally, adjusting the dynamic feedwater flow setting value of the supercritical unit includes:

[0045] The dynamic feed water flow setting value of the supercritical unit is adjusted by adjusting the feed water flow coefficient.

[0046] It can be seen from the above technical solutions that the supercritical unit feedwater flow wide load stability control system provided by the present invention has the following advantages:

[0047] The supercritical unit feedwater flow wide load stability control system provided by the present invention calculates the static feedwater flow setting value of the supercritical unit based on the load setting value of the supercritical unit and the dynamic feedwater flow setting value of the supercritical unit based on the dynamic feedforward amount of the fuel amount, the main steam pressure value and the main steam pressure setting value, and calculates the total feedwater flow setting value of the supercritical unit in combination with the separator temperature correction coefficient. It can meet the stability and rapid response requirements at the same time, maintain a good control effect under different operating conditions and changes in boiler fuel quality, and avoid the stability risk brought by a single control strategy. It does not rely on manual operation and judgment, and solves the technical problems of insufficient response speed, limited control accuracy, reduced stability and insufficient automation in the traditional supercritical unit feedwater flow control method during the unit wide load adjustment process. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0049] Figure 1 It is a structural schematic diagram of a wide load stability control system for feed water flow of a supercritical unit provided in an embodiment of the present invention;

[0050] Figure 2 It is a principle block diagram of a wide load stability control system for feed water flow of a supercritical unit provided in an embodiment of the present invention;

[0051] Figure 3 The present invention provides a flow chart of a method for controlling the wide load of feed water flow of a supercritical unit in an embodiment of the present invention. DETAILED DESCRIPTION

[0052] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0053] For easier understanding, see Figure 1 The present invention provides an embodiment of a supercritical unit feedwater flow wide load stability control system, including a static feedwater flow set value calculation module, a dynamic feedwater flow set value calculation module, a separator outlet temperature correction module and a total feedwater flow set value output module.

[0054] The static feedwater flow set value calculation module is used to calculate the static feedwater flow set value of the supercritical unit according to the load set value of the supercritical unit. The static feedwater flow is the required feedwater flow of the supercritical unit under stable operating conditions.

[0055] The dynamic feedwater flow set value calculation module is used to calculate the dynamic feedwater flow set value of the supercritical unit based on the dynamic feedforward amount of fuel quantity, the main steam pressure value and the main steam pressure set value. The dynamic feedwater flow is the additional feedwater flow that the supercritical unit needs to increase under variable operating conditions to overcome the boiler combustion inertia and pipeline flow inertia.

[0056] The separator outlet temperature correction module is used to calculate the separator temperature correction coefficient according to the separator outlet temperature value and the separator outlet temperature setting value.

[0057] The total feedwater flow set value output module is used to calculate the total feedwater flow set value of the supercritical unit according to the static feedwater flow set value, the dynamic feedwater flow set value and the separator temperature correction coefficient.

[0058] It should be noted that the static feedwater flow set value calculation module collects the load set value of the supercritical unit in real time, and calculates the required feedwater flow set value of the supercritical unit under stable conditions according to the load set value of the supercritical unit. Specifically, a function model of the load set value and the feedwater flow of the supercritical unit is established, and the load set value of the supercritical unit is substituted into the function model to calculate the static feedwater flow set value. The feedwater flow required by the supercritical unit under stable conditions (stable parameters such as load and temperature) is the static feedwater flow. The static feedwater flow can effectively ensure that the boiler feedwater flow is adapted to the load of the supercritical unit, so that the boiler does not produce a large coal and water imbalance during operation.

[0059] In one embodiment, Figure 2As shown, the static feedwater flow setting value calculation module includes a load setting submodule, a first function submodule and a first inertia link submodule. The load setting submodule is used to obtain the load setting value of the supercritical unit. The first function submodule is used to calculate the required feedwater flow of the supercritical unit under stable conditions according to the load setting value of the supercritical unit. The first inertia link submodule is used to perform first-order inertia link filtering on the required feedwater flow of the supercritical unit under stable conditions to effectively remove some disturbances.

[0060] The additional feedwater flow rate required to overcome the boiler combustion inertia and pipeline flow inertia under the changing operating conditions (load, feedwater, temperature and other parameters) of the supercritical unit is the dynamic feedwater flow rate. Figure 2 As shown, the dynamic feedwater flow set value calculation module includes a signal acquisition submodule, a second inertia link submodule, a first PID controller submodule, a first summation submodule, a first multiplication submodule and a constant submodule. The signal acquisition submodule is used to obtain the dynamic feedforward amount of fuel, the main steam pressure value and the main steam pressure set value. The dynamic feedforward amount of fuel is the additional amount of fuel added on the basis of the corresponding fuel amount when the load is steady to overcome the inertia of the boiler. The dynamic feedforward amount of fuel is a parameter obtained in advance. The second inertia link submodule is used to filter the dynamic feedforward amount of fuel based on the first-order inertia link. The first PID controller submodule is used to obtain the first PID correction amount of the deviation between the main steam pressure value and the main steam pressure set value. The first summation submodule is used to superimpose the first deviation with the dynamic feedforward amount of fuel output by the second inertia link submodule to obtain the dynamic fuel amount. The constant submodule is used to configure the feedwater flow coefficient. The first multiplication submodule is used to multiply the dynamic fuel amount by the feedwater flow coefficient to obtain the dynamic feedwater flow set value of the supercritical unit. The dynamic feedforward amount of the fuel quantity after smoothing and filtering by the second inertia link submodule and the PID correction amount of the deviation between the main steam pressure value and the main steam pressure setting value are summed and calculated by the first summation submodule to form the dynamic fuel quantity. The dynamic fuel quantity and the feedwater flow coefficient of the constant submodule are multiplied by the first multiplication submodule to obtain the dynamic feedwater flow setting value of the supercritical unit.

[0061] The separator outlet temperature correction module calculates the separator temperature correction coefficient according to the separator outlet temperature value and the separator outlet temperature setting value. Figure 2As shown, the separator outlet temperature correction module includes a separator outlet temperature acquisition submodule, a separator outlet temperature setting submodule, a second PID controller submodule and a second function submodule. The separator outlet temperature acquisition submodule is used to obtain the separator outlet temperature value. The separator outlet temperature setting submodule is used to configure the separator outlet temperature setting value. The second PID controller submodule is used to calculate the second PID correction value of the deviation between the separator outlet temperature value and the separator outlet temperature setting value. The second function submodule is used to convert the second deviation value into a separator temperature correction coefficient in the range of 0.8~1.2. The separator outlet temperature value and the separator outlet temperature setting value are input into the second PID controller submodule to generate a separator temperature correction signal in the range of 0~100%, which is then converted into a separator temperature correction coefficient in the range of 0.8~1.2 by the second function submodule.

[0062] The total feedwater flow set value output module calculates the total feedwater flow set value of the supercritical unit according to the static feedwater flow set value of the supercritical unit, the dynamic feedwater flow set value of the supercritical unit and the separator temperature correction coefficient. Figure 2 As shown, the total feedwater flow set value output module includes a second summing submodule and a second multiplication submodule. The second summing submodule is used to superimpose and sum the feedwater flow of the critical unit under stable conditions and the feedwater flow of the supercritical unit under variable conditions to obtain the total feedwater flow. The second multiplication submodule is used to multiply the total feedwater flow by the separator temperature correction coefficient to obtain the total feedwater flow set value of the supercritical unit. The control system then performs wide load stability control according to the total feedwater flow set value of the supercritical unit.

[0063] In one embodiment, the dynamic feedwater flow setting value calculation module also includes an adjustment submodule. The adjustment submodule is used to determine whether the proportion of the dynamic feedwater flow setting value of the supercritical unit to the total feedwater flow setting value of the supercritical unit is less than a preset percentage. If so, no adjustment is made. If not, the dynamic feedwater flow setting value of the supercritical unit is adjusted. Specifically, the dynamic feedwater flow setting value of the supercritical unit is adjusted by adjusting the feedwater flow coefficient configured by the constant submodule. In a specific embodiment, the preset percentage is 20%.

[0064] The supercritical unit feedwater flow wide load stability control system provided by the present invention calculates the static feedwater flow setting value of the supercritical unit based on the load setting value of the supercritical unit and the dynamic feedwater flow setting value of the supercritical unit based on the dynamic feedforward amount of the fuel amount, the main steam pressure value and the main steam pressure setting value, and calculates the total feedwater flow setting value of the supercritical unit in combination with the separator temperature correction coefficient. It can meet the stability and rapid response requirements at the same time, maintain a good control effect under different operating conditions and changes in boiler fuel quality, and avoid the stability risk brought by a single control strategy. It does not rely on manual operation and judgment, and solves the technical problems of insufficient response speed, limited control accuracy, reduced stability and insufficient automation in the traditional supercritical unit feedwater flow control method during the unit wide load adjustment process.

[0065] At the same time, the supercritical unit feed water flow wide load stable control system provided by the present invention improves the control accuracy, thereby avoiding the technical problem that the supercritical unit equipment operates under abnormal conditions, thereby accelerating the wear and aging of the equipment and shortening the service life of the equipment.

[0066] At the same time, the supercritical unit feed water flow wide load stable control system provided by the present invention also avoids the risk of coal-water imbalance when the fuel quality changes greatly, which is caused by the existing control system that uses the boiler main control output as the main line to calculate the feed water flow setting and is supplemented by the separator outlet temperature correction or enthalpy correction to calculate the feed water flow setting. At the same time, it avoids the technical problem that the feed water flow setting is prone to large fluctuations when the unit wide load changes or the unit frequency modulation mode, which poses a greater risk to the unit wide load operation.

[0067] For easier understanding, see Figure 3 The present invention provides an embodiment of a method for stabilizing the feed water flow rate of a supercritical unit with a wide load. The method for stabilizing the feed water flow rate of a supercritical unit with a wide load is applied to each supercritical unit feed water flow rate wide load stabilization control system provided in the present invention. The method for stabilizing the feed water flow rate of a supercritical unit with a wide load includes:

[0068] Step S1, calculating the static feedwater flow setting value of the supercritical unit according to the load setting value of the supercritical unit.

[0069] Step S2: Calculate the dynamic feedwater flow setting value of the supercritical unit according to the dynamic feedforward amount of the fuel quantity, the main steam pressure value and the main steam pressure setting value.

[0070] Step S3, calculating the separator temperature correction coefficient according to the separator outlet temperature value and the separator outlet temperature setting value.

[0071] Step S4, calculating the total feed water flow setting value of the supercritical unit according to the static feed water flow setting value of the supercritical unit, the dynamic feed water flow setting value of the supercritical unit and the separator temperature correction coefficient.

[0072] In one embodiment, after step S4, the method further includes:

[0073] Step S5, determine whether the proportion of the dynamic feedwater flow setting value of the supercritical unit to the total feedwater flow setting value of the supercritical unit is less than a preset percentage, if so, do not make any adjustment, if not, adjust the dynamic feedwater flow setting value of the supercritical unit. Specifically, the dynamic feedwater flow setting value of the supercritical unit is adjusted by adjusting the feedwater flow coefficient. The preset percentage is 20%.

[0074] The supercritical unit feed water flow wide load stability control method provided in the present invention is applied to the supercritical unit feed water flow wide load stability control system provided in the present invention. Its principle and technical effects are the same as those of the supercritical unit feed water flow wide load stability control system provided in the present invention, and will not be repeated here.

[0075] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A wide load stability control system for feedwater flow of a supercritical unit, characterized in that: It includes a static water supply flow set value calculation module, a dynamic water supply flow set value calculation module, a separator outlet temperature correction module and a total water supply flow set value output module; The static feedwater flow rate setting value calculation module is used to calculate the static feedwater flow rate setting value of the supercritical unit according to the load setting value of the supercritical unit, and the static feedwater flow rate is the required feedwater flow rate of the supercritical unit under stable working conditions; The dynamic feedwater flow rate setting value calculation module is used to calculate the dynamic feedwater flow rate setting value of the supercritical unit according to the dynamic feedforward amount of the fuel amount, the main steam pressure value and the main steam pressure setting value, wherein the dynamic feedwater flow rate is the additional feedwater flow rate that the supercritical unit needs to increase under variable operating conditions to overcome the boiler combustion inertia and pipeline flow inertia; The separator outlet temperature correction module is used to calculate the separator temperature correction coefficient according to the separator outlet temperature value and the separator outlet temperature setting value; The total feedwater flow set value output module is used to calculate the total feedwater flow set value of the supercritical unit according to the static feedwater flow set value, the dynamic feedwater flow set value and the separator temperature correction coefficient.

2. The wide load stability control system for feedwater flow of supercritical units according to claim 1 is characterized in that: The static water flow rate setting value calculation module includes a load setting submodule, a first function submodule and a first inertia link submodule; The load setting submodule is used to obtain the load setting value of the supercritical unit; The first function submodule is used to calculate the static feedwater flow setting value of the supercritical unit according to the load setting value of the supercritical unit; The first inertia link submodule is used to perform first-order inertia link filtering on the static water feed flow setting value of the supercritical unit.

3. The supercritical unit feedwater flow wide load stability control system according to claim 1, characterized in that: The dynamic water flow set value calculation module includes a signal acquisition submodule, a second inertia link submodule, a first PID controller submodule, a first summation submodule, a first multiplication submodule and a constant submodule; The signal acquisition submodule is used to obtain the dynamic feedforward amount of fuel quantity, the main steam pressure value and the main steam pressure setting value; The second inertia link submodule is used to perform filtering processing on the dynamic feedforward amount of the fuel quantity based on the first-order inertia link; The first PID controller submodule is used for a first PID correction value of a deviation between the main steam pressure value and the main steam pressure setting value; The first summing submodule is used to superimpose the first PID correction amount and the dynamic feedforward amount of the fuel amount output by the second inertia link submodule to obtain a dynamic fuel amount; The constant submodule is used to configure the water flow coefficient; The first multiplication submodule is used to multiply the dynamic fuel amount by the feed water flow coefficient to obtain the dynamic feed water flow setting value of the supercritical unit.

4. The supercritical unit feedwater flow wide load stability control system according to claim 3, characterized in that: The preset percentage is 20%.

5. The wide load stability control system for feedwater flow of supercritical units according to claim 1, characterized in that: The separator outlet temperature correction module includes a separator outlet temperature acquisition submodule, a separator outlet temperature setting submodule, a second PID controller submodule and a second function submodule; The separator outlet temperature acquisition submodule is used to obtain the separator outlet temperature value; The separator outlet temperature setting submodule is used to configure the separator outlet temperature setting value; The second PID controller submodule is used to calculate a second PID correction value of the deviation between the separator outlet temperature value and the separator outlet temperature setting value; The second function submodule is used to convert the second deviation value into a separator temperature correction coefficient in the range of 0.8 to 1.

2.

6. The wide load stability control system for feedwater flow of supercritical units according to claim 1, characterized in that: The total water flow set value output module includes a second summation submodule and a second multiplication submodule; The second summing submodule is used to superimpose and sum the static feedwater flow setting value of the supercritical unit and the dynamic feedwater flow setting value of the supercritical unit to obtain a total feedwater flow; The second multiplication submodule is used to multiply the total feed water flow by the separator temperature correction coefficient to obtain a total feed water flow setting value for the supercritical unit.

7. The wide load stability control system for feedwater flow of supercritical units according to claim 6, characterized in that: The dynamic water flow rate setting value calculation module also includes an adjustment submodule; The adjustment submodule is used to determine whether the proportion of the dynamic water feed flow setting value of the supercritical unit to the total water feed flow setting value of the supercritical unit is less than a preset percentage. If so, no adjustment is made; if not, the dynamic water feed flow setting value of the supercritical unit is adjusted.

8. A method for controlling the wide load stability of feedwater flow of a supercritical unit, characterized in that: The method for stabilizing the feed water flow rate of a supercritical unit with a wide load is applied to a supercritical unit feed water flow rate with a wide load stabilization control system according to any one of claims 1 to 7, and the method for stabilizing the feed water flow rate of a supercritical unit with a wide load stabilization control comprises: Calculating a static feedwater flow setting value of the supercritical unit according to a load setting value of the supercritical unit; Calculating a dynamic feedwater flow setting value of the supercritical unit according to a dynamic feedforward amount of fuel, a main steam pressure value and a main steam pressure setting value; Calculate the separator temperature correction coefficient according to the separator outlet temperature value and the separator outlet temperature setting value; The total feed water flow setting value of the supercritical unit is calculated according to the static feed water flow setting value of the supercritical unit, the dynamic feed water flow setting value of the supercritical unit and the separator temperature correction coefficient.

9. The method for controlling the wide load stability of feedwater flow of a supercritical unit according to claim 8, characterized in that: According to the static feed water flow setting value of the supercritical unit, the dynamic feed water flow setting value of the supercritical unit and the separator temperature correction coefficient, the total feed water flow setting value of the supercritical unit is calculated, and then the following further comprises: Determine whether the proportion of the dynamic water feed flow setting value of the supercritical unit to the total water feed flow setting value of the supercritical unit is less than a preset percentage. If so, do not make any adjustment; if not, adjust the dynamic water feed flow setting value of the supercritical unit.

10. The method for controlling the wide load stability of feedwater flow of a supercritical unit according to claim 9, characterized in that: The step of adjusting the dynamic feedwater flow setting value of the supercritical unit comprises: The dynamic feed water flow setting value of the supercritical unit is adjusted by adjusting the feed water flow coefficient.

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