Boiler heating surface pipe overtemperature leakage early warning method and system based on pressure monitoring

Abstract

The invention discloses a boiler heating surface pipe overtemperature leakage early warning method and system based on pressure monitoring, and the method comprises the steps: inputting real-time working condition information into a heat-fluid-solid coupling calculation model of a heating surface pipe, and determining a normal operation pressure drop critical value and an overtemperature pressure drop early warning value corresponding to the design requirement upper limit temperature through numerical simulation; calculating real-time steam pressure drop data of an inlet and an outlet according to the obtained real-time steam pressure data of the outlet and the real-time steam pressure data of the inlet; comparing the inlet and outlet real-time steam pressure drop data with a normal operation critical value and an overtemperature pressure drop early warning value respectively, and performing boiler heating surface pipe overtemperature leakage early warning; by monitoring the steam pressure at the inlet and the outlet of the heating surface pipe, the overtemperature leakage of the heating surface pipe is early warned, and the suspicious overtemperature leakage position is determined.

Description

Technical Field

[0001] The invention relates to the technical field of reliability maintenance engineering of power station boilers, and in particular to a method and system for early warning of over-temperature leakage of boiler heating surface tubes based on pressure monitoring. Background Art

[0002] Ultra-supercritical units have gradually become peak-shaving units in the power grid. The proportion of unit operation time under variable load conditions has increased significantly. Frequent rapid load-changing operations of peak-shaving units will inevitably lead to rapid changes in the working environment of boiler heating surface tubes, including increased fluctuations in boiler flue gas temperature, steam temperature and pressure. The heating surface is more likely to have thermal deviations and local overtemperatures under variable load conditions, thereby causing overtemperature leakage. Unplanned shutdown events caused by overtemperature leakage of heating surface tubes have also increased sharply in recent years, seriously affecting the safety of unit operation. Therefore, it is of great significance to provide early warning for overtemperature leakage of boiler heating surface tubes.

[0003] At present, due to the high temperature working environment and complex spatial layout in the boiler, there are few temperature measurement points and most of them are arranged in the low temperature area. It is difficult to obtain the temperature distribution of the entire heating surface tube through direct monitoring means to warn of over-temperature leakage. At present, the temperature of the boiler tube wall is mainly estimated by the standard thermal calculation method with the help of the temperature measurement points on the outer wall of the boiler. However, for variable load conditions, such as the wall temperature estimation result of the deviation of the steam flow rate in the tube, there is a large error. At the same time, the current research on the over-temperature of the heating surface tube is mostly focused on the temperature change on the flue gas side and the influence of high-temperature oxidation on the tube wall temperature during the stable operation of the unit. There is little research on the influence of uneven distribution of steam flow in the tube on the tube wall temperature during the variable load operation of the peak-shaving unit, and there is a lack of systematic theoretical guidance for the safe operation of the peak-shaving unit.

[0004] In the related art, a method for visualizing the maintenance status of the heating surface in boiler operation and maintenance is proposed in a patent application document with publication number CN113313816A. The method is based on three-dimensional digital model technology, and three-dimensionally models the heating surface of the boiler and the boiler equipment. The established three-dimensional model is used as a carrier to remotely display the dynamic parameters of the boiler operation in real time in the form of graphics. The document scheme realizes the visualization of the maintenance status of the heating surface by collecting real-time wall temperature data. It is based on database technology and requires the pre-input of historical data (the required amount of input data is large). The database data is obtained through the SIS (Safety Instrumented System) system and compared with the real-time wall temperature to divide the risk level. The established three-dimensional model of the heating surface of the boiler and the boiler equipment is used as a display carrier without performing any calculations. Summary of the invention

[0005] The technical problem to be solved by the present invention is how to realize over-temperature leakage warning of boiler heating surface tubes under variable load conditions of peak-shaving units.

[0006] The present invention solves the above technical problems by the following technical means:

[0007] A boiler heating surface tube over-temperature leakage early warning method based on pressure monitoring is proposed, the method comprising:

[0008] The real-time operating condition information is input into the thermal-fluid-solid coupling calculation model of the heated surface tube, and the normal operating pressure drop threshold value and over-temperature pressure drop warning value corresponding to the upper limit temperature of the design requirement are determined through numerical simulation;

[0009] Calculate the real-time steam pressure drop data at the inlet and outlet according to the acquired real-time steam pressure data at the outlet and the real-time steam pressure data at the inlet;

[0010] The real-time steam pressure drop data of the inlet and outlet are compared with the normal operation critical value and the over-temperature pressure drop warning value respectively, and an over-temperature leakage warning of the boiler heating surface tube is issued.

[0011] Furthermore, before inputting the real-time operating condition information into the thermal-fluid-solid coupling calculation model of the heated surface tube and determining the normal operating pressure drop threshold value and the over-temperature pressure drop warning value corresponding to the design required upper limit temperature through numerical simulation, the method further includes:

[0012] The basic information of the heating surface tubes and the boiler design and operation parameter information are extracted, and a thermal-fluid-solid coupling calculation model of the heating surface tubes is established.

[0013] Furthermore, the extraction of basic information of the heating surface tubes and boiler design and operation parameter information, and establishment of a thermal-fluid-solid coupling calculation model of the heating surface tubes include:

[0014] Extracting basic information of a single heating surface tube and boiler design and operation parameter information, wherein the basic information includes geometric structure, specification size, material and thermophysical parameter information, and the boiler design and operation parameter information includes size, composition and thermophysical parameter information of the steam fluid domain in the heating surface tube;

[0015] The fluid domain outside a single heating surface tube is omitted to construct a geometric model of the heating surface tube.

[0016] According to the geometric structure of a single heating surface tube and the boiler design and operation parameter information, the finite volume method is used to perform numerical simulation and determine the algorithm model;

[0017] Based on the geometric model and the algorithm model, the boundary conditions of the steam fluid domain inside the heating surface tube and the heat exchange boundary conditions of the tube outer wall are set to establish a heat-fluid-solid coupling calculation model of the heating surface tube.

[0018] Furthermore, the real-time operating condition information is input into the heat-fluid-solid coupling calculation model of the heated surface tube, and the normal operating pressure drop threshold value and the over-temperature pressure drop warning value corresponding to the upper limit temperature of the design requirement are determined through numerical simulation, including:

[0019] The real-time operating condition information is input into the heat-fluid-solid coupling calculation model of the heating surface tube, and the real-time steam temperature, steam flow rate, inlet and outlet steam pressure drop and tube wall temperature are numerically simulated, and the inlet and outlet steam pressure drop is adjusted to change the outlet steam temperature, so as to determine the normal operating pressure drop threshold value corresponding to the upper limit temperature required by the design;

[0020] The real-time operating condition information is input into the heat-fluid-solid coupling calculation model of the heated surface tube, and the inlet and outlet steam pressure drops are adjusted to change the tube wall temperature so that the maximum tube wall temperature reaches the design allowable temperature, and the over-temperature pressure drop warning value is determined;

[0021] The real-time operating condition information includes the flue gas outlet temperature, inlet temperature and flow rate information.

[0022] Furthermore, the functional relationship between the outlet steam temperature and the inlet and outlet steam pressure drop is:

[0023] T S =-30.104ln(ΔP-0.0283)+547.975

[0024] Where, T S is the outlet steam temperature, and ΔP is the inlet and outlet steam pressure drop.

[0025] Furthermore, the functional relationship between the maximum temperature of the tube wall and the inlet and outlet steam pressure drop is:

[0026] T W =-31.96ln(ΔP-0.0272)+579.056

[0027] Where, T W is the maximum temperature of the tube wall, and ΔP is the inlet and outlet steam pressure drop.

[0028] Further, the real-time steam pressure drop data at the inlet and outlet is calculated based on the acquired real-time steam pressure data at the outlet and the real-time steam pressure data at the inlet, including:

[0029] Use steam pressure sensors at the outlet and inlet of the heating surface tube to obtain real-time steam pressure data at the outlet and inlet;

[0030] Subtract the inlet real-time steam pressure data from the outlet real-time steam pressure data to obtain the inlet and outlet real-time steam pressure drop data.

[0031] Furthermore, the real-time steam pressure drop data of the inlet and outlet are compared with the normal operation critical value and the over-temperature pressure drop warning value respectively to provide an over-temperature leakage warning for the heating surface tube of the boiler, including:

[0032] When the real-time steam pressure drop data of the inlet and outlet is greater than the normal operating critical value, it indicates that the heating surface tube is operating normally;

[0033] When the real-time steam pressure drop data at the inlet and outlet is less than the over-temperature pressure drop warning value, a warning of over-temperature leakage of the heating surface pipe is issued;

[0034] When the real-time steam pressure drop data at the inlet and outlet is less than the normal operation critical value and greater than the over-temperature pressure drop warning value, a manual evaluation is prompted.

[0035] In addition, the present invention also proposes a boiler heating surface tube overtemperature leakage early warning system based on pressure monitoring, the device comprising:

[0036] The model simulation module is used to input the real-time operating condition information into the thermal-fluid-solid coupling calculation model of the heated surface tube, and determine the normal operating pressure drop threshold value and over-temperature pressure drop warning value corresponding to the upper limit temperature required by the design through numerical simulation;

[0037] A real-time pressure drop calculation module is used to calculate the real-time steam pressure drop data of the inlet and outlet according to the acquired real-time steam pressure data of the outlet and the real-time steam pressure data of the inlet;

[0038] The early warning module is used to compare the real-time steam pressure drop data at the inlet and outlet with the normal operation critical value and the over-temperature pressure drop early warning value respectively, and to issue an early warning of over-temperature leakage of the boiler heating surface tube.

[0039] In addition, the present invention also proposes a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the above-mentioned boiler heating surface tube overtemperature leakage early warning method based on pressure monitoring is implemented.

[0040] The advantages of the present invention are:

[0041] Since the function of the heating surface tube in the power station boiler is to transfer the heat from the flue gas side to the steam side so that the steam is heated up to facilitate work, the temperature of the heating surface tube wall is affected by the absorption of heat from the flue gas side and the release of heat to the steam side. When the working conditions on the flue gas side remain unchanged, when the flow rate on the steam side decreases, its heat carrying capacity decreases, resulting in the tube wall absorbing more heat than releasing heat, and the tube wall temperature rises, which poses a risk of over-temperature leakage. When the specifications of the heating surface tube are fixed, the steam flow rate is closely related to the inlet and outlet steam pressure drop, and the inlet and outlet steam pressure is easy to monitor. Therefore, the present invention can achieve early warning of over-temperature leakage of the heating surface tube and determine the suspected over-temperature leakage position by monitoring the steam pressure at the inlet and outlet of the heating surface tube, thereby solving the problem that conventional temperature measurement-based methods cannot accurately calculate the tube wall temperature and predict the over-temperature of the tube wall, and are particularly not suitable for early warning of over-temperature leakage of the tube wall under variable load conditions. It has the advantages of real-time monitoring of pressure data and rapid prediction under variable load conditions, and is very suitable for early warning of over-temperature of the boiler heating surface tube, and can prevent the heating surface tube from operating at over-temperature for a long time.

[0042] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a flow chart of a boiler heating surface tube over-temperature leakage early warning method based on pressure monitoring proposed in one embodiment of the present invention;

[0044] Figure 2 It is a schematic diagram of determining a normal operation critical value and an over-temperature pressure drop warning value according to numerical simulation results in one embodiment of the present invention;

[0045] Figure 3 It is a structural schematic diagram of a boiler heating surface tube overtemperature leakage early warning system based on pressure monitoring proposed in one embodiment of the present invention. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are 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.

[0047] like Figure 1 As shown, an embodiment of the present invention proposes a boiler heating surface tube over-temperature leakage early warning method based on pressure monitoring, the method comprising the following steps:

[0048] S10, inputting the real-time operating condition information into the heat-fluid-solid coupling calculation model of the heated surface pipe, and determining the normal operating pressure drop threshold value and the over-temperature pressure drop warning value corresponding to the upper limit temperature required by the design through numerical simulation;

[0049] S20, calculating the real-time steam pressure drop data at the inlet and outlet according to the acquired real-time steam pressure data at the outlet and the real-time steam pressure data at the inlet;

[0050] S30, comparing the real-time steam pressure drop data of the inlet and outlet with the normal operation critical value and the over-temperature pressure drop warning value respectively, and issuing an over-temperature leakage warning for the boiler heating surface tube.

[0051] It should be noted that this embodiment analyzes the corresponding relationship between steam pressure and tube wall temperature through numerical simulation, determines the over-temperature pressure drop warning value, and then compares the real-time pressure drop data to determine whether over-temperature leakage occurs, thereby warning of over-temperature leakage of the heating surface tube and ensuring the safe operation of the boiler unit.

[0052] As a further preferred technical solution, in step S10: inputting the real-time operating condition information into the thermal-fluid-solid coupling calculation model of the heated surface tube, and determining the normal operating pressure drop threshold value and the over-temperature pressure drop warning value corresponding to the upper limit temperature required by the design through numerical simulation, the method further includes the following steps:

[0053] S10', extracting basic information of the heating surface tubes and boiler design and operation parameter information, and establishing a thermal-fluid-solid coupling calculation model of the heating surface tubes.

[0054] As a further preferred technical solution, the step S10': extracting basic information of the heating surface tubes and boiler design and operation parameter information, and establishing a thermal-fluid-solid coupling calculation model of the heating surface tubes, specifically includes the following steps:

[0055] S11', extracting basic information of a single heating surface tube and boiler design and operation parameter information, wherein the basic information includes geometric structure, specification size, material and thermophysical parameter information, and the boiler design and operation parameter information includes size, composition and thermophysical parameter information of the steam fluid domain in the heating surface tube;

[0056] S12', omitting the outer fluid domain of a single heating surface tube and constructing a geometric model of the heating surface tube;

[0057] S13', according to the geometric structure of a single heating surface tube and the boiler design and operation parameter information, the finite volume method is used to perform numerical simulation to determine the algorithm model;

[0058] S14', based on the geometric model and the algorithm model, set the steam fluid domain boundary conditions in the heating surface tube and the tube outer wall heat exchange boundary conditions, and establish a heat-fluid-solid coupling calculation model for the heating surface tube.

[0059] Specifically, this embodiment takes the modeling process of a single heating surface tube of a high-temperature superheater of a 1000MW unit as an example:

[0060] Establish a geometric model of the heating surface tube: extract the geometric structure, specifications, dimensions, material and thermophysical parameter information of a single heating surface tube, as well as the dimensions, composition and thermophysical parameter information of the steam fluid domain in the heating surface tube, assign material properties based on the geometric structure characteristics, omit the fluid domain outside the tube of a single heating surface tube, set three boundary layers at the junction of the steam flow field and the tube wall, divide the heating surface tube wall and steam boundary layer into structured grids, and divide the steam fluid domain in the remaining tube into unstructured grids. The number of model units is 1,106,167;

[0061] Establish an algorithm model: According to the geometric characteristics of the heating surface tube and the properties of the steam fluid, the finite volume method is used for numerical simulation, and the basic control equations of energy conservation, mass conservation and momentum conservation are established. The standard k-ε turbulence model, standard wall function method and fluid-solid coupling boundary conditions are selected for the steam fluid in the heating surface tube, and the conduction, convection and radiation heat transfer models are set. Convection boundary conditions and radiation boundary conditions are set on the outside of the tube wall to replace the effect of high-temperature flue gas outside the wall;

[0062] Establishment of thermal-fluid-solid coupling calculation model of heating surface tubes: Based on the established geometric model of heating surface tubes, the algorithm model is adopted to set the boundary conditions of the steam fluid domain in the heating surface tubes, including the input interfaces of the inlet and outlet pressure boundaries and the inlet temperature boundaries, and establish the thermal-fluid-solid coupling calculation model of the heating surface tubes.

[0063] As a further preferred technical solution, the step S10: inputting the real-time operating condition information into the thermal-fluid-solid coupling calculation model of the heated surface tube, and determining the normal operating pressure drop threshold value and the over-temperature pressure drop warning value corresponding to the upper limit temperature of the design requirement through numerical simulation, specifically includes the following steps:

[0064] S11, inputting the real-time operating condition information into the heat-fluid-solid coupling calculation model of the heating surface tube, numerically simulating the real-time steam temperature, steam flow, inlet and outlet steam pressure drop and tube wall temperature, adjusting the inlet and outlet steam pressure drop to change the outlet steam temperature, and determining the normal operating pressure drop threshold value corresponding to the upper limit temperature required by the design;

[0065] Specifically, the real-time operating condition information extracted in this embodiment includes the flue gas side outlet temperature, inlet temperature and flow information, and the wall external convection heat transfer coefficient and radiation heat transfer coefficient are set for different positions of the geometric model. The real-time operating condition steam inlet temperature and inlet and outlet pressure information are extracted, and input into the heat-fluid-solid coupling calculation model of the heating surface tube corresponding to a single heating surface tube of the high-temperature superheater of the 1000MW unit through the reserved interface. The pressure-based coupling solver is used to set the time step, calculation increment step and convergence target value to perform numerical simulation; then the outlet steam temperature in the simulation result is extracted and compared with the outlet steam temperature in the boiler design operation parameters to determine whether it is within the specified range; Figure 2 As shown in the figure, when the inlet steam pressure remains unchanged, the inlet and outlet pressure drops are changed by adjusting the outlet steam pressure, and the functional relationship between the outlet steam temperature and the inlet and outlet pressure drops is established as follows:

[0066] T S =-30.104ln(ΔP-0.0283)+547.975

[0067] Where, T S is the outlet steam temperature, ΔP is the inlet and outlet pressure drop;

[0068] It is determined that the inlet and outlet steam pressure drop threshold value corresponding to the outlet steam temperature reaching the design upper limit temperature (605℃) is 0.179MPa.

[0069] S12, inputting the real-time operating condition information into the heat-fluid-solid coupling calculation model of the heated surface tube, adjusting the inlet and outlet steam pressure drop to change the tube wall temperature so that the maximum tube wall temperature reaches the design allowable temperature, and determining the over-temperature pressure drop warning value.

[0070] Specifically, this embodiment sets the wall external convection heat transfer coefficient and radiation heat transfer coefficient for different positions of the geometric model, extracts the real-time working condition steam inlet temperature and inlet and outlet pressure information, and inputs them into the heat-fluid-solid coupling calculation model corresponding to the single heating surface tube of the high-temperature superheater of the 1000MW unit established above through the reserved interface, adopts the pressure-based coupling solver, sets the time step, calculation increment step and convergence target value, and performs numerical simulation; determines the position of the maximum tube wall temperature in the simulation result, extracts the maximum tube wall temperature and compares it with the design allowable tube wall temperature in the boiler design operation parameters to determine whether it is within the allowable range; Figure 2 As shown in the figure, under the condition that the inlet steam pressure remains unchanged, the inlet and outlet pressure drops are changed by adjusting the outlet steam pressure, and the functional relationship between the maximum temperature of the tube wall and the inlet and outlet pressure drops is established as follows:

[0071] T W =-31.96ln(ΔP-0.0272)+579.056

[0072] Where, T W is the maximum temperature of the tube wall, ΔP is the inlet and outlet pressure drop;

[0073] It is thus determined that the over-temperature pressure drop warning value corresponding to the maximum pipe wall temperature reaching the design allowable temperature (645°C) is 0.155MPa.

[0074] As a further preferred technical solution, the step S20: calculating the real-time steam pressure drop data at the inlet and outlet according to the acquired real-time steam pressure data at the outlet and the real-time steam pressure data at the inlet, specifically includes:

[0075] Use steam pressure sensors at the outlet and inlet of the heating surface tube to obtain real-time steam pressure data at the outlet and inlet;

[0076] Subtract the inlet real-time steam pressure data from the outlet real-time steam pressure data to obtain the inlet and outlet real-time steam pressure drop data.

[0077] As a further preferred technical solution, the step S30: comparing the real-time steam pressure drop data of the inlet and outlet with the normal operation critical value and the over-temperature pressure drop warning value respectively, and performing an over-temperature leakage warning for the heating surface tube of the boiler, specifically comprises the following steps:

[0078] S31, when the real-time steam pressure drop data at the inlet and outlet is greater than the normal operating critical value, it is indicated that the heating surface tube is operating normally;

[0079] Specifically, for example, a set of real-time inlet and outlet steam pressure data is obtained by using steam pressure sensors at the inlet and outlet positions of the heating surface tubes. The real-time inlet and outlet steam pressure drop data obtained by subtracting the inlet steam pressure from the outlet steam pressure is 0.182 MPa.

[0080] Compare the real-time steam pressure drop data at the inlet and outlet with the normal operating critical value and the over-temperature pressure drop warning value. If the real-time pressure drop at the inlet and outlet of 0.182MPa is greater than the normal operating critical value of 0.179MPa, a warning decision will be made: no warning, normal operation.

[0081] S32, when the real-time steam pressure drop data at the inlet and outlet is less than the over-temperature pressure drop warning value, a warning of over-temperature leakage of the heating surface pipe is issued;

[0082] Specifically, for example, a set of real-time inlet and outlet steam pressure data is obtained by using the steam pressure sensor at the inlet and outlet of the heated surface pipe, and the real-time inlet and outlet steam pressure drop data is obtained by subtracting the inlet steam pressure from the outlet steam pressure, which is 0.150MPa; the real-time inlet and outlet steam pressure drop data is compared with the normal operating critical value and the over-temperature pressure drop warning value. If the real-time inlet and outlet steam pressure drop of 0.150MPa is less than the over-temperature pressure drop warning value of 0.155MPa, a warning decision is made: an over-temperature leakage warning is issued for the heated surface pipe, and the position of the highest temperature on the pipe wall is taken as the suspected over-temperature leakage position.

[0083] S33. When the real-time steam pressure drop data at the inlet and outlet is less than the normal operation critical value and greater than the over-temperature pressure drop warning value, a manual evaluation is prompted.

[0084] Specifically, for example, a set of real-time inlet and outlet steam pressure data is obtained by using the steam pressure sensor at the inlet and outlet of the heated surface pipe. The real-time inlet and outlet steam pressure drop data is 0.168 MPa obtained by subtracting the inlet steam pressure from the outlet steam pressure. The real-time inlet and outlet steam pressure drop data is compared with the normal operating critical value and the over-temperature pressure drop warning value. If the real-time inlet and outlet pressure drop of 0.168 MPa is less than the normal operating critical value of 0.179 MPa, and greater than the over-temperature pressure drop warning value of 0.155 MPa, a warning decision is made: prompting manual evaluation.

[0085] This embodiment is based on numerical simulation technology and uses boiler design information to establish a thermal-fluid-solid coupling calculation model for the heating surface tubes, collects and inputs real-time operating condition information, makes a warning judgment by comparing the simulation results with the design requirements, and realizes over-temperature warning of the boiler heating tubes under the variable load condition of the peak-shaving unit by only collecting real-time steam pressure data (a small amount of input data is required), thereby solving the problem of difficult measurement of the wall temperature of the heating surface in the boiler and a small number of measurement points.

[0086] In addition, if Figure 3 As shown, an embodiment of the present invention further proposes a boiler heating surface tube overtemperature leakage early warning system based on pressure monitoring, the device comprising:

[0087] The model simulation module 10 is used to input the real-time operating condition information into the thermal-fluid-solid coupling calculation model of the heating surface pipe, and determine the normal operating pressure drop threshold value and the over-temperature pressure drop warning value corresponding to the upper limit temperature required by the design through numerical simulation;

[0088] A real-time pressure drop calculation module 20 is used to calculate the real-time steam pressure drop data of the inlet and outlet according to the acquired real-time steam pressure data of the outlet and the real-time steam pressure data of the inlet;

[0089] The early warning module 30 is used to compare the real-time steam pressure drop data of the inlet and outlet with the normal operation critical value and the over-temperature pressure drop early warning value respectively, and to issue an early warning of over-temperature leakage of the boiler heating surface tube.

[0090] As a further preferred technical solution, the system further includes a model building module for extracting basic information of the heating surface tubes and boiler design and operation parameter information, and establishing a thermal-fluid-solid coupling calculation model of the heating surface tubes.

[0091] As a further preferred technical solution, the model building module specifically includes:

[0092] An information extraction unit, used to extract basic information of a single heating surface tube and boiler design and operation parameter information, wherein the basic information includes geometric structure, specification size, material and thermophysical parameter information, and the boiler design and operation parameter information includes size, composition and thermophysical parameter information of the steam fluid domain in the heating surface tube;

[0093] The geometric model building unit is used to omit the outer fluid domain of a single heating surface tube and build a geometric model of the heating surface tube;

[0094] The algorithm model calculation unit is used to determine the algorithm model by numerical simulation using the finite volume method according to the geometric structure of a single heating surface tube and the boiler design and operation parameter information;

[0095] The heat-fluid-solid coupling calculation model establishment unit is used to set the steam fluid domain boundary conditions in the heating surface tube and the heat exchange boundary conditions on the outer wall of the tube based on the geometric model and the algorithm model, and establish the heat-fluid-solid coupling calculation model of the heating surface tube.

[0096] As a further preferred technical solution, the model simulation module 10 specifically includes:

[0097] The first simulation determination unit is used to input the real-time operating condition information into the thermal-fluid-solid coupling calculation model of the heating surface tube, and numerically simulate the real-time steam temperature, steam flow, inlet and outlet steam pressure drop and tube wall temperature, and adjust the inlet and outlet steam pressure drop to change the outlet steam temperature, so as to determine the normal operating pressure drop threshold value corresponding to the upper limit temperature required by the design;

[0098] The second simulation determination unit is used to input the real-time operating condition information into the thermal-fluid-solid coupling calculation model of the heating surface tube, and adjust the inlet and outlet steam pressure drop to change the tube wall temperature so that the maximum tube wall temperature reaches the design allowable temperature, and determine the over-temperature pressure drop warning value;

[0099] The real-time operating condition information includes the flue gas outlet temperature, inlet temperature and flow rate information.

[0100] As a further preferred technical solution, the real-time pressure drop calculation module 20 is specifically used for:

[0101] Use steam pressure sensors at the outlet and inlet of the heating surface tube to obtain real-time steam pressure data at the outlet and inlet;

[0102] Subtract the inlet real-time steam pressure data from the outlet real-time steam pressure data to obtain the inlet and outlet real-time steam pressure drop data.

[0103] As a further preferred technical solution, the early warning module 30 is specifically used for:

[0104] When the real-time steam pressure drop data of the inlet and outlet is greater than the normal operating critical value, it indicates that the heating surface tube is operating normally;

[0105] When the real-time steam pressure drop data at the inlet and outlet is less than the over-temperature pressure drop warning value, a warning of over-temperature leakage of the heating surface pipe is issued;

[0106] When the real-time steam pressure drop data at the inlet and outlet is less than the normal operation critical value and greater than the over-temperature pressure drop warning value, a manual evaluation is prompted.

[0107] It should be noted that other embodiments or specific implementation methods of the boiler heating surface tube over-temperature leakage warning system based on pressure monitoring described in the present invention can refer to the above-mentioned method embodiments, which will not be repeated here.

[0108] In addition, an embodiment of the present invention further proposes a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the boiler heating surface tube over-temperature leakage warning method based on pressure monitoring as described in the previous embodiment is implemented.

[0109] Of course, the data comparison and judgment process in the above embodiment can be implemented by a program and can be run on a storage medium or a terminal device. Meanwhile, in other embodiments, each parameter of the above embodiment can be replaced according to specific circumstances.

[0110] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection portion with one or more wirings (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0111] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0112] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0113] 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 at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0114] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A boiler heating surface tube over-temperature leakage early warning method based on pressure monitoring, characterized in that: The method comprises: The real-time operating condition information is input into the thermal-fluid-solid coupling calculation model of the heated surface tube, and the normal operating pressure drop threshold value and over-temperature pressure drop warning value corresponding to the upper limit temperature of the design requirement are determined through numerical simulation; Calculate the real-time steam pressure drop data at the inlet and outlet according to the acquired real-time steam pressure data at the outlet and the real-time steam pressure data at the inlet; The real-time steam pressure drop data of the inlet and outlet are compared with the normal operation critical value and the over-temperature pressure drop warning value respectively, and an over-temperature leakage warning of the boiler heating surface tube is issued.

2. The boiler heating surface tube over-temperature leakage early warning method based on pressure monitoring according to claim 1 is characterized in that: Before inputting the real-time operating condition information into the thermal-fluid-solid coupling calculation model of the heated surface tube and determining the normal operating pressure drop threshold value and the over-temperature pressure drop warning value corresponding to the design required upper limit temperature through numerical simulation, the method further includes: The basic information of the heating surface tubes and the boiler design and operation parameter information are extracted, and a thermal-fluid-solid coupling calculation model of the heating surface tubes is established.

3. The boiler heating surface tube over-temperature leakage early warning method based on pressure monitoring according to claim 2 is characterized in that: The extracting of basic information of the heating surface tubes and boiler design and operation parameter information, and establishing a thermal-fluid-solid coupling calculation model of the heating surface tubes, includes: Extracting basic information of a single heating surface tube and boiler design and operation parameter information, wherein the basic information includes geometric structure, specification size, material and thermophysical parameter information, and the boiler design and operation parameter information includes size, composition and thermophysical parameter information of the steam fluid domain in the heating surface tube; The fluid domain outside a single heating surface tube is omitted to construct a geometric model of the heating surface tube. According to the geometric structure of a single heating surface tube and the boiler design and operation parameter information, the finite volume method is used to perform numerical simulation and determine the algorithm model; Based on the geometric model and the algorithm model, the boundary conditions of the steam fluid domain inside the heating surface tube and the heat exchange boundary conditions of the tube outer wall are set to establish a heat-fluid-solid coupling calculation model of the heating surface tube.

4. The boiler heating surface tube over-temperature leakage early warning method based on pressure monitoring according to claim 1 is characterized in that: The real-time operating condition information is input into the heat-fluid-solid coupling calculation model of the heated surface tube, and the normal operating pressure drop threshold value and the over-temperature pressure drop warning value corresponding to the upper limit temperature of the design requirement are determined through numerical simulation, including: The real-time operating condition information is input into the heat-fluid-solid coupling calculation model of the heating surface tube, and the real-time steam temperature, steam flow rate, inlet and outlet steam pressure drop and tube wall temperature are numerically simulated, and the inlet and outlet steam pressure drop is adjusted to change the outlet steam temperature, so as to determine the normal operating pressure drop threshold value corresponding to the upper limit temperature required by the design; The real-time operating condition information is input into the heat-fluid-solid coupling calculation model of the heated surface tube, and the inlet and outlet steam pressure drops are adjusted to change the tube wall temperature so that the maximum tube wall temperature reaches the design allowable temperature, and the over-temperature pressure drop warning value is determined; The real-time operating condition information includes the flue gas outlet temperature, inlet temperature and flow rate information.

5. The boiler heating surface tube over-temperature leakage early warning method based on pressure monitoring according to claim 4 is characterized in that: The functional relationship between the outlet steam temperature and the inlet and outlet steam pressure drop is: T S =-30.104ln(ΔP-0.0283)+547.975 Where, T S is the outlet steam temperature, and ΔP is the inlet and outlet steam pressure drop.

6. The boiler heating surface tube over-temperature leakage early warning method based on pressure monitoring according to claim 4 is characterized in that: The functional relationship between the maximum tube wall temperature and the inlet and outlet steam pressure drop is: T W =-31.96ln(ΔP-0.0272)+579.056 Where, T W is the maximum temperature of the tube wall, and ΔP is the inlet and outlet steam pressure drop.

7. The boiler heating surface tube over-temperature leakage early warning method based on pressure monitoring according to claim 1, characterized in that: The method of calculating the real-time steam pressure drop data at the inlet and outlet according to the acquired real-time steam pressure data at the outlet and the real-time steam pressure data at the inlet includes: Use steam pressure sensors at the outlet and inlet of the heating surface tube to obtain real-time steam pressure data at the outlet and inlet; Subtract the inlet real-time steam pressure data from the outlet real-time steam pressure data to obtain the inlet and outlet real-time steam pressure drop data.

8. The boiler heating surface tube over-temperature leakage early warning method based on pressure monitoring according to claim 1, characterized in that: The real-time steam pressure drop data of the inlet and outlet are compared with the normal operation critical value and the over-temperature pressure drop warning value respectively to provide an over-temperature leakage warning for the heating surface tube of the boiler, including: When the real-time steam pressure drop data of the inlet and outlet is greater than the normal operating critical value, it indicates that the heating surface tube is operating normally; When the real-time steam pressure drop data at the inlet and outlet is less than the over-temperature pressure drop warning value, a warning of over-temperature leakage of the heating surface pipe is issued; When the real-time steam pressure drop data at the inlet and outlet is less than the normal operation critical value and greater than the over-temperature pressure drop warning value, a manual evaluation is prompted.

9. A boiler heating surface tube overtemperature leakage early warning system based on pressure monitoring, characterized in that: The device comprises: The model simulation module is used to input the real-time operating condition information into the thermal-fluid-solid coupling calculation model of the heated surface tube, and determine the normal operating pressure drop threshold value and over-temperature pressure drop warning value corresponding to the upper limit temperature required by the design through numerical simulation; A real-time pressure drop calculation module is used to calculate the real-time steam pressure drop data of the inlet and outlet according to the acquired real-time steam pressure data of the outlet and the real-time steam pressure data of the inlet; The early warning module is used to compare the real-time steam pressure drop data at the inlet and outlet with the normal operation critical value and the over-temperature pressure drop early warning value respectively, and to issue an early warning of over-temperature leakage of the boiler heating surface tube.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 8 is implemented.

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