Checking and judging method for meter steam flow through fuel quantity disturbance and related product

Abstract

The invention discloses a method for checking and judging meter steam flow through fuel quantity disturbance and a related product, and belongs to the technical field of thermal equipment performance state diagnosis. According to the method for checking and judging the meter steam flow through the fuel quantity disturbance, the function relation between the actual steam specific volume and the steam pressure and the function relation between the actual steam specific volume and the steam temperature are established, a parameter change characteristic derivation formula under the steady-state working condition after the fuel quantity disturbance is combined, and the influence of multi-parameter coupling fluctuation caused by the fuel quantity disturbance on the steam flow is fully considered; calculation deviation caused by the fact that parameters are difficult to accurately obtain in actual production is avoided, a more accurate meter steam flow variation calculation result can be provided, and reliable data support is provided for unit operation. Meanwhile, a large number of accurate equipment parameters and operation data do not need to be obtained, the calculation process is simplified, the meter steam flow checking result can be provided for operation personnel in time, the operation personnel can make adjustment conveniently and rapidly, and stable operation of a unit is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal equipment performance status diagnosis, and in particular to a method for calibrating and determining the effect of fuel quantity disturbance on meter steam flow, and related products. Background Art

[0002] In modern thermal power generation systems, the DC boiler is the core equipment of the unit. Its operating quality directly determines the stability and economy of power production. Fuel quantity disturbance, as a typical operating condition change, will cause coupled fluctuations in multiple parameters such as steam temperature and pressure, resulting in measurement deviations in the steam flow meter. Accurately grasping the variation law of this parameter is of great engineering value to achieving safe and economical operation of the unit.

[0003] Traditional methods for calculating the impact of fuel quantity disturbances on metered steam flow rely primarily on complex mechanism models. The construction of these models is extremely cumbersome and requires a large amount of precise equipment parameters and operating data. However, in actual production environments, these parameters are often difficult to accurately obtain due to factors such as complex and variable equipment operating conditions and limited precision of measuring instruments. This results in significant deviations in the calculation results based on the mechanism models and an inability to provide reliable data support for unit operation. While numerical simulation methods can theoretically achieve relatively accurate results, they consume significant computing resources and are time-consuming, failing to meet the needs of real-time monitoring and rapid analysis. During actual unit operation, operators need to promptly understand the impact of fuel quantity disturbances on metered steam flow so they can make rapid adjustments to ensure stable unit operation. However, existing numerical simulation methods are insufficiently timely, making it difficult to meet this practical need.

[0004] In summary, the existing methods have defects such as complex calculations, large result deviations, and poor timeliness, which make it difficult to provide operators with a reliable basis for meter steam flow calibration. Therefore, there is an urgent need to develop an efficient and accurate method. Summary of the Invention

[0005] The purpose of the present invention is to provide a method and related products for calibrating and determining the steam flow of a meter under fuel quantity disturbance, so as to overcome the problem in the prior art that the steam flow of a DC boiler meter cannot be effectively calibrated under fuel quantity disturbance.

[0006] The present invention solves the above technical problems through the following technical solutions: A method for verifying the effect of fuel quantity disturbance on the steam flow of a meter comprises the following steps: Based on the steam state equation, the functional relationship between the actual steam specific volume and the changes in steam pressure and steam temperature is constructed, and the first expression of the actual steam specific volume change is established by combining the differential theory; According to the changing characteristics of steam pressure and steam temperature under steady-state conditions after fuel quantity disturbance, the second expression of meter steam flow and the third expression of actual steam flow are established respectively. The fourth expression of meter steam flow is derived by eliminating irrelevant variables through simultaneous equation. The fourth expression is differentiated and a steady-state constraint is introduced. Combined with the first expression of the specific volume change, the fifth expression of the meter steam flow change is derived. By collecting the unit operation data and combining it with the fifth expression to calculate the change in the meter steam flow rate, it is determined whether the change in the meter steam flow rate is zero. If the judgment result is no, the meter needs to be calibrated; if the judgment result is yes, the meter does not need to be calibrated.

[0007] A further improvement of the present invention is that the first expression for the actual steam specific volume change is specifically:

[0008] in, is the actual steam specific volume change; is the actual steam specific volume; is the steam pressure change; is the steam temperature change; is the partial derivative of the actual steam specific volume with respect to pressure; is the partial derivative of the actual steam specific volume with respect to temperature.

[0009] A further improvement of the present invention is that the second expression of the meter steam flow is specifically:

[0010] in, For metering steam flow; is the change in pressure difference before and after the throttle orifice; is the steam specific volume of the throttling orifice; is the steam flow coefficient.

[0011] A further improvement of the present invention is that the third expression of the actual steam flow rate is specifically:

[0012] in, is the actual steam flow rate.

[0013] A further improvement of the present invention is that the fourth expression of the metered steam flow is specifically: .

[0014] A further improvement of the present invention is that the fifth expression for the change in the steam flow rate of the meter is specifically:

[0015] in, is the change in the metered steam flow rate.

[0016] A further improvement of the present invention is that the unit operation data includes: meter steam flow , steam pressure change , steam temperature change , partial derivative of actual steam specific volume with respect to pressure and the partial derivative of the actual steam specific volume with respect to temperature .

[0017] The present invention also provides a system for verifying and determining the effect of fuel quantity disturbance on meter steam flow, comprising: The first module is used to construct the functional relationship between the actual steam specific volume and the changes in steam pressure and steam temperature based on the steam state equation, and to establish the first expression of the actual steam specific volume change in combination with differential theory; The second module is used to establish a second expression for the meter steam flow rate and a third expression for the actual steam flow rate based on the changing characteristics of the steam pressure and steam temperature under steady-state conditions after the fuel quantity disturbance, and to derive a fourth expression for the meter steam flow rate by simultaneously eliminating irrelevant variables; The third module is used to perform differential processing on the fourth expression and introduce steady-state condition constraints, and combine it with the first expression of specific volume change to derive a fifth expression of meter steam flow change; The fourth module is used to collect the unit operation data, calculate the meter steam flow change in combination with the fifth expression, and determine whether the meter steam flow change is zero. If the judgment result is no, the meter needs to be calibrated; if the judgment result is yes, the meter does not need to be calibrated.

[0018] The present invention also provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of the method for calibrating and determining the effect of fuel quantity disturbance on the steam flow of a meter are implemented.

[0019] The present invention also provides a computer program product, comprising a computer program, which, when executed by a processor, implements the steps of the above-mentioned method for calibrating and determining the effect of fuel quantity disturbance on meter steam flow.

[0020] Compared with the prior art, the present invention has the following positive effects: The method for calibrating and determining the effect of fuel quantity disturbance on meter steam flow provided by the present invention establishes a functional relationship between actual steam specific volume and steam pressure and steam temperature, and derives a formula based on the parameter change characteristics under steady-state conditions after the fuel quantity disturbance. It fully considers the influence of multi-parameter coupling fluctuations caused by the fuel quantity disturbance on the steam flow, avoids calculation deviations caused by the difficulty in accurately obtaining parameters in actual production, and can provide more accurate calculation results of meter steam flow changes, providing reliable data support for unit operation. At the same time, there is no need to obtain a large amount of precise equipment parameters and operating data, which simplifies the calculation process and can provide meter steam flow calibration results to operating personnel in a timely manner, facilitating operators to make quick adjustments and ensure stable operation of the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings in the specification are used to provide further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0022] Figure 1 The present invention is a flow chart of a method for calibrating and determining the effect of fuel quantity disturbance on meter steam flow. DETAILED DESCRIPTION

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying 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 making creative efforts shall fall within the scope of protection of the present invention.

[0024] In the description of the present invention, it is to be understood that the terms “include” and “comprise” indicate the presence of the described features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or collections thereof.

[0025] It should also be understood that the terms used in the present specification are only for the purpose of describing particular embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0026] It should be understood that although the terms "first," "second," and "third" may be used to describe preset ranges in embodiments of the present invention, these preset ranges should not be limited to these terms. These terms are merely used to distinguish one preset range from another. For example, without departing from the scope of embodiments of the present invention, the first preset range may also be referred to as the second preset range, and similarly, the second preset range may also be referred to as the first preset range.

[0027] The word "if," as used herein, may be interpreted as "at the time of" or "when" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrases "if it is determined" or "if (stated condition or event) is detected" may be interpreted as "when it is determined" or "in response to the determination" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)," depending on the context.

[0028] The accompanying drawings illustrate various schematic diagrams of structures according to embodiments disclosed herein. These figures are not drawn to scale; for clarity, some details are exaggerated and some details may be omitted. The shapes of the various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary and may deviate in practice due to manufacturing tolerances or technical limitations. Those skilled in the art may design regions / layers with different shapes, sizes, and relative positions as needed.

[0029] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, which are intended to explain the present invention rather than to limit it.

[0030] See also Figure 1 A method for verifying the effect of fuel quantity disturbance on the steam flow of a meter comprises the following steps: Based on the steam state equation, the functional relationship between the actual steam specific volume and the changes in steam pressure and steam temperature is constructed, and the first expression of the actual steam specific volume change is established by combining the differential theory; According to the changing characteristics of steam pressure and steam temperature under steady-state conditions after fuel quantity disturbance, the second expression of meter steam flow and the third expression of actual steam flow are established respectively. The fourth expression of meter steam flow is derived by eliminating irrelevant variables through simultaneous equation. The fourth expression is differentiated and a steady-state constraint is introduced. Combined with the first expression of the specific volume change, the fifth expression of the meter steam flow change is derived. By collecting the unit operation data and combining it with the fifth expression to calculate the change in the meter steam flow rate, it is determined whether the change in the meter steam flow rate is zero. If the judgment result is no, the meter needs to be calibrated; if the judgment result is yes, the meter does not need to be calibrated.

[0031] The method for calibrating and determining the effect of fuel quantity disturbance on meter steam flow provided by the present invention establishes a functional relationship between actual steam specific volume and steam pressure and steam temperature, and derives a formula based on the parameter change characteristics under steady-state conditions after the fuel quantity disturbance. It fully considers the influence of multi-parameter coupling fluctuations caused by the fuel quantity disturbance on the steam flow, avoids calculation deviations caused by the difficulty in accurately obtaining parameters in actual production, and can provide more accurate calculation results of meter steam flow changes, providing reliable data support for unit operation. At the same time, there is no need to obtain a large amount of precise equipment parameters and operating data, which simplifies the calculation process and can provide meter steam flow calibration results to operating personnel in a timely manner, facilitating operators to make quick adjustments and ensure stable operation of the unit.

[0032] Specifically, the first expression of the actual steam specific volume change is:

[0033] in, is the actual steam specific volume change; is the actual steam specific volume; is the steam pressure change; is the steam temperature change; is the partial derivative of the actual steam specific volume with respect to pressure; is the partial derivative of the actual steam specific volume with respect to temperature.

[0034] Specifically, the second expression of the meter steam flow is:

[0035] in, For metering steam flow; is the change in pressure difference before and after the throttle orifice; is the steam specific volume of the throttling orifice; is the steam flow coefficient.

[0036] Specifically, the third expression of the actual steam flow rate is:

[0037] in, is the actual steam flow rate.

[0038] Specifically, the fourth expression of the meter steam flow is: .

[0039] Specifically, the steady-state condition constraint is: the steam pressure at the outlet of the DC furnace remains constant, that is, , the fifth expression of the meter steam flow change is specifically:

[0040] in, is the change in the metered steam flow rate.

[0041] Specifically, the unit operation data includes: metered steam flow , steam pressure change , steam temperature change , partial derivative of actual steam specific volume with respect to pressure and the partial derivative of the actual steam specific volume with respect to temperature .

[0042] Based on the same inventive concept, the present invention provides a system for verifying and determining the effect of fuel quantity disturbance on meter steam flow, comprising: The first module is used to construct the functional relationship between the actual steam specific volume and the changes in steam pressure and steam temperature based on the steam state equation, and to establish the first expression of the actual steam specific volume change in combination with differential theory; The second module is used to establish a second expression for the meter steam flow rate and a third expression for the actual steam flow rate based on the changing characteristics of the steam pressure and steam temperature under steady-state conditions after the fuel quantity disturbance, and to derive a fourth expression for the meter steam flow rate by simultaneously eliminating irrelevant variables; The third module is used to perform differential processing on the fourth expression and introduce steady-state condition constraints, and combine it with the first expression of specific volume change to derive a fifth expression of meter steam flow change; The fourth module is used to collect the unit operation data, calculate the meter steam flow change in combination with the fifth expression, and determine whether the meter steam flow change is zero. If the judgment result is no, the meter needs to be calibrated; if the judgment result is yes, the meter does not need to be calibrated.

[0043] Example 1 Taking a 600MW supercritical coal-fired power unit as an example, the unit operating data is collected based on thermodynamic charts and unit operating conditions, as shown in Table 1. It is determined whether the meter needs to be calibrated when a 1% fuel quantity disturbance occurs in the unit.

[0044] Table 1 Unit operating data

[0045] (1) Based on the first expression, determine the actual steam specific volume change

[0046] (2) Calculate the change in steam flow rate using the fifth expression

[0047] (3) The steam flow change on the meter is not zero, and the meter needs to be calibrated.

[0048] The present invention provides a method for verifying the effect of fuel quantity disturbance on the steam flow of a meter, based on the following concepts: According to the principle of conservation of energy, by analyzing the relationship between the heat absorption of the direct current furnace and the heat absorption process of the working fluid, and combining the functional characteristics of the working fluid enthalpy value with temperature and pressure and the turbine flow calculation model, a reasonable simplified assumption is adopted to optimize the calculation process, and the influence of fuel quantity disturbance on the steam flow and other parameters of the meter at the key node of the direct current furnace is derived; according to the law of conservation of energy, the basic principles of thermodynamics, and the relevant theories of fluid mechanics, the principle followed by the implementation of the technical solution of the present invention can be further proposed, namely: 1. Use the law of conservation of energy to determine the balance between the heat absorbed by the DC furnace and the heat of the working fluid, providing a basis for subsequent derivation; 2. Consider the working fluid characteristics to derive parameter relationships. Steam specific volume is a function of pressure and temperature. Utilizing this characteristic, through calculations, we describe the relationship between working fluid specific volume, temperature, and pressure changes under fuel quantity disturbances. This is then used to derive formulas for calculating the change in metered steam flow at the turbine inlet and at a specific point in the steam-water flow path of the once-through boiler. 3. When analyzing the impact of fuel quantity disturbances on the metered steam flow rate at a certain point in the steam-water flow process of a once-through boiler, and the impact of the metered steam flow rate, formulas derived from fluid mechanics theory are used to establish the relationship between various parameters, thereby enabling the calculation and analysis of changes in the corresponding parameters.

[0049] This method solves the problem that the steam flow of the DC boiler meter cannot be effectively calibrated under fuel quantity disturbance. Through reasonable simplification, it can quickly and relatively accurately obtain results, which in practice helps operators optimize operations and ensure stable and economical operation of the unit.

[0050] Based on the same inventive concept, an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program. When the computer program is executed by a processor, the computer-readable storage medium implements the steps of the method for calibrating and determining the effect of fuel quantity disturbance on the steam flow rate of the meter. Specifically, the computer-readable storage medium includes, but is not limited to, volatile memory and / or non-volatile memory. The volatile memory may include RAM (Random Access Memory) and / or cache memory, etc. The non-volatile memory may include ROM (Read-Only Memory), a hard disk, a flash memory, an optical disk, a magnetic disk, etc.

[0051] Based on the same inventive concept, an embodiment of the present application provides a computer program product, which includes a computer program stored on a computer-readable storage medium, and the computer program includes program instructions. When the program instructions are executed by a computer device, the computer device executes the steps of the above-mentioned method for calibrating and determining the effect of fuel quantity disturbance on the steam flow of the meter.

[0052] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM (Compact Disc Read-Only Memory), optical storage, etc.) containing computer-usable program code.

[0053] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer device or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0054] These computer program instructions may also be stored in a computer readable memory that can direct a computer device or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0055] These computer program instructions can also be loaded onto a computer device or other programmable data processing device so that a series of operating steps are executed on the computer device or other programmable device to produce a process implemented by the computer device, thereby providing instructions for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0056] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0057] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A method for verifying the effect of fuel quantity disturbance on steam flow meter, characterized in that: The following steps are involved: Based on the steam state equation, the functional relationship between the actual steam specific volume and the changes in steam pressure and steam temperature is constructed, and the first expression of the actual steam specific volume change is established by combining the differential theory; According to the changing characteristics of steam pressure and steam temperature under steady-state conditions after fuel quantity disturbance, the second expression of meter steam flow and the third expression of actual steam flow are established respectively. The fourth expression of meter steam flow is derived by eliminating irrelevant variables through simultaneous equation. The fourth expression is differentiated and a steady-state constraint is introduced. Combined with the first expression of the specific volume change, the fifth expression of the meter steam flow change is derived. By collecting the unit operation data, the steam flow change of the meter is calculated in combination with the fifth expression, and it is determined whether the steam flow change of the meter is zero. If the determination result is no, the meter needs to be calibrated. If the judgment result is yes, there is no need to calibrate the meter.

2. The method for verifying and determining the effect of fuel quantity disturbance on steam flow meter according to claim 1, characterized in that: The first expression of the actual steam specific volume change is specifically: in, is the actual steam specific volume change; is the actual steam specific volume; is the steam pressure change; is the steam temperature change; is the partial derivative of the actual steam specific volume with respect to pressure; is the partial derivative of the actual steam specific volume with respect to temperature.

3. The method for verifying and determining the effect of fuel quantity disturbance on steam flow meter according to claim 2, characterized in that: The second expression of the meter steam flow is specifically: in, For metering steam flow; is the change in pressure difference before and after the throttle orifice; is the steam specific volume of the throttling orifice; is the steam flow coefficient.

4. The method for verifying and determining the effect of fuel quantity disturbance on steam flow meter according to claim 3, characterized in that: The third expression of the actual steam flow rate is specifically: in, is the actual steam flow rate.

5. The method for verifying and determining the effect of fuel quantity disturbance on steam flow meter according to claim 4, characterized in that: The fourth expression of the meter steam flow is specifically: 。 6. A method for checking and determining the effect of fuel quantity disturbance on steam flow meter according to claim 5, characterized in that: The fifth expression of the meter steam flow change is specifically: in, is the change in the metered steam flow rate.

7. The method for verifying and determining the effect of fuel quantity disturbance on steam flow meter according to claim 1, characterized in that: The unit operation data includes: metered steam flow , steam pressure change , steam temperature change , partial derivative of actual steam specific volume with respect to pressure and the partial derivative of the actual steam specific volume with respect to temperature .

8. A system for checking and determining the effect of fuel quantity disturbance on steam flow meter, characterized in that: include: The first module is used to construct the functional relationship between the actual steam specific volume and the changes in steam pressure and steam temperature based on the steam state equation, and to establish the first expression of the actual steam specific volume change in combination with differential theory; The second module is used to establish a second expression for the meter steam flow rate and a third expression for the actual steam flow rate based on the changing characteristics of the steam pressure and steam temperature under steady-state conditions after the fuel quantity disturbance, and to derive a fourth expression for the meter steam flow rate by simultaneously eliminating irrelevant variables; The third module is used to perform differential processing on the fourth expression and introduce steady-state condition constraints, and combine it with the first expression of specific volume change to derive a fifth expression of meter steam flow change; The fourth module is used to collect the unit operation data, calculate the meter steam flow change in combination with the fifth expression, and determine whether the meter steam flow change is zero. If the determination result is no, the meter needs to be calibrated; If the judgment result is yes, there is no need to calibrate the meter.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for calibrating and determining the effect of fuel quantity disturbance on meter steam flow as described in any one of claims 1 to 7 are implemented.

10. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method for calibrating and determining the effect of fuel quantity disturbance on meter steam flow are implemented as described in any one of claims 1 to 7.

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