A method for monitoring the contamination status of platen superheater tubes in ultra-supercritical boilers

Abstract

The present application proposes a method, device and storage medium for monitoring the contamination status of platen superheater tubes of ultra-supercritical boilers, which obtains the first historical data of the DCS / SIS system within a preset time and the second historical data of the test point of the platen superheater tube within a preset time; obtains the third historical data of the platen superheater tube without a test point by calculation based on the first historical data; obtains the actual heat transfer coefficient of the heating surface by calculation based on the structural parameters of the platen superheater, the second historical data and the third historical data; obtains the ideal heat transfer coefficient of the heating surface by calculation based on the heat transfer principle of the heating surface; obtains the cleaning factor of the heating surface based on the actual heat transfer coefficient of the heating surface and the ideal heat transfer coefficient of the heating surface, and monitors the contamination status of the platen superheater tubes through the cleaning factor of the heating surface. The present disclosure reduces costs, realizes real-time monitoring of the contamination status of the platen superheater, and ensures the reliability of the calculated values ​​of the contamination factors of different parts of the platen superheater.

Description

Technical Field

[0001] The present application relates to the technical field of contamination status monitoring, and in particular to a method, device and storage medium for monitoring the contamination status of a platen superheater tube of an ultra-supercritical boiler. Background Art

[0002] At present, the most common phenomenon in the actual operation of power station boilers is the accumulation of dust on the heating surface. It is mainly manifested in that the coal ash particles with a low ash melting point melt in the high-temperature area and then condense on the surface of the convection heating surface pipe in the horizontal flue with a slightly lower temperature. During the long-term operation of the boiler, the pipe contamination problem often leads to a serious lack of heat absorption by the pipe, affecting the hydrodynamic characteristics of the heating surface, increasing thermal deviation, and causing a series of serious consequences such as pipe bursting on the heating surface. Therefore, effective monitoring of the pipe contamination status is one of the key points of metal supervision and operation optimization in the daily operation of thermal power plants.

[0003] In the prior art, pressure sensors can be installed in the cross-sections where the outlets and inlets of each convective heating surface in the horizontal flue are located, so as to obtain the pressure difference at the flue inlet and outlet cross-sections of each convective heating surface to characterize the contamination of the heating surface; or, by collecting the key parameters of each convective heating surface at each moment, such as the inlet and outlet steam temperature of the working fluid, the working fluid flow rate, the inlet and outlet cross-section flue gas temperature, etc., the ratio of the actual heat absorption of each heating surface to the ideal heat absorption at each moment can be calculated in real time, so as to judge the contamination status of each convective heating surface.

[0004] However, in the process of evaluating the degree of contamination based on the pressure difference between the inlet and outlet sections of the heating surface, a large number of pressure measuring instruments need to be configured, which results in a high investment cost. In addition, the working environment of the boiler convection heating surface is complex. Affected by the different contamination locations and contamination components, the real-time calculated value of the pressure difference may not be able to accurately and quickly reflect the current contamination situation of the heating surface, resulting in deviations in the judgment of the contamination situation and a low accuracy rate. Summary of the invention

[0005] The present application provides a method, device and storage medium for monitoring the contamination status of platen superheater tubes of an ultra-supercritical boiler, so as to at least solve the technical problems arising in the above-mentioned related technologies.

[0006] The first embodiment of the present application provides a method for monitoring the contamination status of a platen superheater tube of an ultra-supercritical boiler, the method comprising:

[0007] Acquire the first historical data of the DCS / SIS system within a preset time and the second historical data of the test point of the platen superheater tube within the preset time;

[0008] According to the first historical data, third historical data of the platen superheater tube without measuring points is obtained by calculation;

[0009] According to the structural parameters of the platen superheater, the second historical data and the third historical data, an actual heat transfer coefficient of the heating surface is obtained by calculation;

[0010] According to the heat transfer principle of the heated surface, the ideal heat transfer coefficient of the heated surface is calculated;

[0011] According to the actual heat transfer coefficient of the heating surface and the ideal heat transfer coefficient of the heating surface, a heating surface cleanliness factor is obtained, and the contamination state of the platen superheater tube is monitored by the heating surface cleanliness factor.

[0012] Optionally, in one embodiment of the present disclosure, the first historical data includes outlet steam temperature, outlet pressure, inlet steam temperature and inlet pressure; the third historical data without measuring points of the platen superheater tube obtained by calculation according to the first historical data includes:

[0013] calculating outlet enthalpy based on the outlet steam temperature and the outlet pressure;

[0014] calculating an inlet enthalpy based on the inlet steam temperature and the inlet pressure;

[0015] Calculating the inter-screen thermal deviation coefficient and the same-screen thermal deviation coefficient according to the outlet enthalpy and the inlet enthalpy;

[0016] Calculating the enthalpy increase of the heated surface without measuring points according to the inter-screen thermal deviation coefficient and the same-screen thermal deviation coefficient;

[0017] According to the enthalpy increase of the heating surface, the outlet steam temperature of the platen superheater tube without measuring point is obtained by calculation.

[0018] Optionally, in one embodiment of the present disclosure, obtaining the actual heat transfer coefficient of the heating surface by calculation according to the structural parameters of the platen superheater, the second historical data and the third historical data includes:

[0019] According to the structural parameters of the platen superheater, the flow rate of each pipe on the heating surface is obtained;

[0020] According to the flow rate of each tube of the heating surface, the second historical data and the third historical data, the heat absorption amount of each tube of the platen superheater is obtained by calculation;

[0021] Obtaining the flue gas temperature and steam temperature of the heating surface, and obtaining the average value of the overall temperature and pressure of the heating surface based on the flue gas temperature and steam temperature of the heating surface;

[0022] Based on the average value of the overall temperature and pressure of the heating surface and the amount of heat absorbed by each tube of the platen superheater, the actual heat transfer coefficient of the heating surface is obtained.

[0023] Optionally, in one embodiment of the present disclosure, obtaining the actual heat transfer coefficient of the heating surface based on the average value of the overall temperature and pressure of the heating surface and the heat absorption of each tube of the platen superheater includes:

[0024] Correcting the average value of the overall temperature and pressure of the heating surface to obtain a corrected average value of the overall temperature and pressure of the heating surface;

[0025] Based on the corrected average value of the overall temperature and pressure of the heating surface and the amount of heat absorbed by each tube of the platen superheater, the actual heat transfer coefficient of the heating surface is obtained.

[0026] Optionally, in one embodiment of the present disclosure, the heat absorption amount of each tube of the platen superheater is obtained by calculation according to the flow rate of each tube of the heating surface, the second historical data and the third historical data, including:

[0027] According to the second historical data and the third historical data, the inlet enthalpy and the outlet enthalpy of each tube of the platen superheater are obtained;

[0028] According to the flow rate of each tube of the heating surface and the inlet enthalpy and outlet enthalpy of each tube of the platen superheater, the heat absorption of each tube of the platen superheater is obtained by calculation.

[0029] Optionally, in one embodiment of the present disclosure, obtaining the heating surface cleaning factor based on the actual heat transfer coefficient of the heating surface and the ideal heat transfer coefficient of the heating surface includes: determining the ratio of the actual heat transfer coefficient of the heating surface to the ideal heat transfer coefficient of the heating surface as the heating surface cleaning factor.

[0030] Optionally, in one embodiment of the present disclosure, monitoring the contamination state of the platen superheater tube by the heating surface cleaning factor includes:

[0031] If the heating surface cleaning factor is in the first interval range, the platen superheater tube is in the first state;

[0032] If the heat cleaning factor is in the second interval range, the platen superheater tube is in the second state;

[0033] If the heat cleaning factor is in the third interval range, the platen superheater tube is in the third state.

[0034] The second aspect of the present application provides a device for monitoring the contamination status of a platen superheater tube of an ultra-supercritical boiler, the device comprising:

[0035] An acquisition module, used for acquiring first historical data of a DCS / SIS system within a preset time and second historical data of a test point of a platen superheater tube within the preset time;

[0036] A first calculation module, configured to obtain third historical data of the platen superheater tube without measuring points by calculation according to the first historical data;

[0037] A second calculation module is used to obtain an actual heat transfer coefficient of a heating surface by calculation according to the structural parameters of the platen superheater, the second historical data and the third historical data;

[0038] The third calculation module is used to calculate the ideal heat transfer coefficient of the heating surface according to the heat transfer principle of the heating surface;

[0039] The monitoring module is used to obtain a heating surface cleanliness factor according to the actual heat transfer coefficient of the heating surface and the ideal heat transfer coefficient of the heating surface, and monitor the contamination state of the platen superheater tube through the heating surface cleanliness factor.

[0040] The electronic device proposed in the embodiment of the third aspect of the present invention includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the method described in the first aspect above can be implemented.

[0041] The computer storage medium proposed in the fourth aspect of the embodiment of the present invention stores computer executable instructions; after the computer executable instructions are executed by the processor, the method described in the first aspect above can be implemented.

[0042] The technical solution provided by the embodiments of the present application brings at least the following beneficial effects:

[0043] The method, device and storage medium for monitoring the contamination state of the platen superheater tube of the ultra-supercritical boiler provided by the present disclosure obtain the first historical data of the DCS / SIS system within a preset time and the second historical data of the test point of the platen superheater tube within a preset time; according to the first historical data, the third historical data of the platen superheater tube without a test point is calculated; according to the structural parameters of the platen superheater, the second historical data and the third historical data, the actual heat transfer coefficient of the heating surface is calculated; according to the heat transfer principle of the heating surface, the ideal heat transfer coefficient of the heating surface is calculated; according to the actual heat transfer coefficient of the heating surface and the ideal heat transfer coefficient of the heating surface, the heating surface cleanliness factor is obtained, and the contamination state of the platen superheater tube is monitored by the heating surface cleanliness factor. Therefore, the historical data required by the present disclosure is convenient to collect, and there is no need to install additional instruments and equipment, which reduces the cost, and the real-time monitoring of the contamination state of the platen superheater is realized through the heating surface cleanliness factor, which ensures the reliability of the calculated value of the contamination factor of different parts of the platen superheater.

[0044] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0046] Figure 1 A schematic flow chart of a method for monitoring the contamination status of a platen superheater tube of an ultra-supercritical boiler according to an embodiment of the present application;

[0047] Figure 2 The present invention is a schematic structural diagram of an ultra-supercritical boiler platen superheater tube contamination status monitoring device provided according to one embodiment of the present application. DETAILED DESCRIPTION

[0048] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0049] The following describes a method and device for monitoring the contamination status of a platen superheater tube of an ultra-supercritical boiler according to an embodiment of the present application with reference to the accompanying drawings.

[0050] Figure 1 The flowchart of the method for monitoring the contamination status of the platen superheater tube of an ultra-supercritical boiler provided according to one embodiment of the present application is as follows: Figure 1 As shown, the method may include the following steps:

[0051] Step 101, obtaining first historical data of a DCS / SIS system within a preset time and second historical data of a point to be tested of a platen superheater tube within a preset time.

[0052] In one embodiment of the present disclosure, first historical data of the heating surface in half a soot blowing cycle after each soot blowing action is performed by the DCS / SIS system of the power plant within a preset time can be obtained according to the contamination characteristics of the platen superheater.

[0053] In one embodiment of the present disclosure, the first historical data may include outlet steam temperature, outlet pressure, inlet steam temperature and inlet pressure. Also, in one embodiment of the present disclosure, the second historical data may include outlet steam temperature of the point to be measured, outlet pressure of the point to be measured and steam flow rate of the point to be measured.

[0054] And, in one embodiment of the present disclosure, the above-mentioned preset time can be set as needed. For example, the preset time is the past week, or the preset time is the past 3 days.

[0055] Step 102: Obtain third historical data of the platen superheater tube without measuring points through calculation according to the first historical data.

[0056] In one embodiment of the present disclosure, there are some tubes in the platen superheater that do not have measuring points, that is, the third historical data of some tubes in the platen superheater cannot be obtained. Based on this, in one embodiment of the present disclosure, the third historical data of the platen superheater tubes without measuring points can be obtained by calculation based on the first historical data.

[0057] Specifically, in one embodiment of the present disclosure, the method for obtaining the third historical data of the platen superheater tube without measuring points by calculation according to the first historical data may include the following steps:

[0058] Step 1, calculating the outlet enthalpy according to the outlet steam temperature and outlet pressure;

[0059] Step 2, calculating the inlet enthalpy based on the inlet steam temperature and the inlet pressure;

[0060] Step 3: Calculate the inter-screen thermal deviation coefficient and the same-screen thermal deviation coefficient based on the outlet enthalpy and the inlet enthalpy;

[0061] Step 4: Calculate the enthalpy increase of the heated surface without measuring points according to the inter-screen thermal deviation coefficient and the same-screen thermal deviation coefficient;

[0062] Step 5: According to the enthalpy increase of the heating surface, the outlet steam temperature of the platen superheater tube without measuring point is obtained by calculation.

[0063] In one embodiment of the present disclosure, the outlet enthalpy can be calculated based on the outlet steam temperature and the outlet pressure according to the functions in the water and water steam IAPWS-IF97 function library, and the inlet enthalpy can be calculated based on the inlet steam temperature and the inlet pressure.

[0064] And, in one embodiment of the present disclosure, after obtaining the outlet enthalpy and the inlet enthalpy through the above steps, the inter-screen thermal deviation coefficient can be calculated by the first formula based on the outlet enthalpy and the inlet enthalpy in the width direction between screens, wherein the first formula is: inter-screen thermal deviation coefficient = (inter-screen outlet enthalpy - inter-screen inlet enthalpy) / average enthalpy increase.

[0065] Furthermore, in one embodiment of the present disclosure, the same-screen thermal deviation coefficient is calculated in the same way as the above-mentioned inter-screen thermal deviation coefficient, and the inter-screen outlet enthalpy and inter-screen inlet enthalpy in the above-mentioned first formula can be replaced with the same-screen outlet enthalpy and the same-screen inlet enthalpy to obtain the same-screen thermal deviation coefficient in the same-screen depth direction.

[0066] Further, in one embodiment of the present disclosure, after obtaining the same-screen thermal deviation coefficient and the inter-screen thermal deviation coefficient through the above steps, the enthalpy increase of the heated surface without measuring points can be calculated by the second formula based on the inter-screen thermal deviation coefficient and the same-screen thermal deviation coefficient, wherein the second formula is: enthalpy increase of heated surface = average enthalpy increase × inter-screen thermal deviation coefficient × same-screen thermal deviation coefficient.

[0067] Further, in one embodiment of the present disclosure, after the enthalpy increase of the heating surface is obtained by the above calculation, the outlet steam temperature of the platen superheater tube without measuring point can be obtained by calculation according to the enthalpy increase of the heating surface. Specifically, in one embodiment of the present disclosure, the outlet enthalpy of the heating surface can be calculated by the third formula through the enthalpy increase of the heating surface and the inlet enthalpy of the heating surface, wherein the third formula is: outlet enthalpy of the heating surface = enthalpy increase of the heating surface + inlet enthalpy of the heating surface. And, in one embodiment of the present disclosure, the outlet steam temperature of the heating surface can be calculated by the function in the IAPWS-IF97 function library based on the outlet pressure of the heating surface and the outlet enthalpy of the heating surface. Among them, in one embodiment of the present disclosure, the outlet pressure of the platen superheater tube without measuring point is the same as the outlet pressure of the point to be measured. In one embodiment of the present disclosure, the above-mentioned inlet enthalpy of the heating surface can be obtained according to the inlet temperature and inlet pressure, and the enthalpy calculation formula in the IAPWS-IF97 function library.

[0068] In one embodiment of the present disclosure, through the above steps, the outlet steam temperature of the platen superheater tube without measuring point can be inferred through the first historical data of the heating surface, so that the heat absorption of each tube of the platen superheater can be obtained based on the outlet steam temperature without measuring point, making the calculation result more accurate.

[0069] Step 103: Obtain the actual heat transfer coefficient of the heating surface through calculation according to the structural parameters of the platen superheater, the second historical data and the third historical data.

[0070] In one embodiment of the present disclosure, after obtaining the third historical data through the above steps, the actual heat transfer coefficient of the heating surface can be obtained by calculation based on the structural parameters of the platen superheater, the second historical data and the third historical data.

[0071] Specifically, in one embodiment of the present disclosure, the method for obtaining the actual heat transfer coefficient of the heating surface by calculation according to the structural parameters of the platen superheater, the second historical data and the third historical data may include the following steps:

[0072] Step 1031, according to the structural parameters of the platen superheater, obtain the flow rate of each pipe on the heating surface;

[0073] Step 1032, according to the flow rate of each pipe on the heating surface, the second historical data and the third historical data, the heat absorption amount of each pipe of the platen superheater is obtained by calculation;

[0074] Step 1033, obtaining the flue gas temperature and steam temperature of the heating surface, and obtaining the average value of the overall temperature and pressure of the heating surface based on the flue gas temperature and steam temperature of the heating surface;

[0075] Step 1034: Obtain the actual heat transfer coefficient of the heating surface based on the average temperature and pressure of the entire heating surface and the heat absorption of each tube of the platen superheater.

[0076] Among them, in one embodiment of the present disclosure, the method for obtaining the flow rate of each pipe on the heating surface according to the structural parameters of the platen superheater may include: determining the flow deviation coefficient of each pipe, and obtaining the flow rate of each pipe on the heating surface according to the flow deviation coefficient of each pipe.

[0077] And, in one embodiment of the present disclosure, the method for determining the flow deviation coefficient of each pipe may include:

[0078]

[0079] Among them, η 10 , η 11 , η 12 , ..., η 1n-1 are the flow non-uniformity coefficients of the 1st, 2nd, 3rd, ..., nth rows of pipes; B1, B2, B3, ..., B n-1 are the coefficients of the 2nd, 3rd, ..., nth row of pipes respectively; K0, K1, K2, ..., K n-1 They are the flow coefficients of the 1st, 2nd, 3rd, …, nth rows of pipes respectively.

[0080] Among them, the above B i It can be calculated as follows:

[0081]

[0082] Among them, b i is the static pressure distribution of the i-th pipe in the manifold, a i is the static pressure distribution of the ith pipe in the distribution header, H fp Enthalpy of the distribution header.

[0083] And, the above flow coefficient K i It can be calculated as follows:

[0084]

[0085] Among them, f i is the total cross-sectional area of ​​the pipe, g is the acceleration due to gravity, U i is the flow rate of the i-th pipe.

[0086] Furthermore, the above coefficient Ai It can be calculated as follows:

[0087]

[0088] Among them, F fp is the flow cross-sectional area of ​​the distribution header, J fi is the specific volume coefficient of the ith tube group.

[0089] Furthermore, the total resistance coefficient Z of the above pipe is i It can be calculated as follows:

[0090]

[0091] Among them, FJ JLQ is the additional resistance of the i-th throttling orifice, λ is the resistance coefficient along the pipe, l is the pipe length, d is the pipe diameter, and ξ is the local resistance coefficient of the pipe.

[0092] Further, the above Z for the pipe inlet without throttling ring / throttling orifice plate i It can be calculated as follows:

[0093]

[0094] Further, in one embodiment of the present disclosure, the method for obtaining the flow rate of each pipe of the heating surface according to the flow rate deviation coefficient of each pipe may specifically include: obtaining the flow rate of each pipe of the heating surface according to the flow rate deviation coefficient of each pipe by a fourth formula, wherein the fourth formula is:

[0095]

[0096] Where D is the total flow rate of the heating surface pipeline, n i is the number of tubes between panels, n j is the number of tubes on the same screen, η ij is the flow deviation coefficient of the i-th screen j tube, D ij is the flow rate of the jth tube on the i-th screen.

[0097] And, in one embodiment of the present disclosure, after the flow rate of each tube of the heating surface is obtained through the above steps, the heat absorption of each tube of the platen superheater can be obtained by calculation according to the flow rate of each tube of the heating surface, the second historical data and the third historical data. Specifically, in one embodiment of the present disclosure, the above method of obtaining the heat absorption of each tube of the platen superheater by calculation according to the flow rate of each tube of the heating surface, the second historical data and the third historical data can specifically include: obtaining the inlet enthalpy and outlet enthalpy of each tube of the platen superheater according to the second historical data and the third historical data; obtaining the heat absorption of each tube of the platen superheater by calculation according to the flow rate of each tube of the heating surface and the inlet enthalpy and outlet enthalpy of each tube of the platen superheater.

[0098] Among them, in one embodiment of the present disclosure, the outlet enthalpy of the test point can be obtained according to the outlet steam temperature and outlet pressure of the test point in the second historical data, and the inlet enthalpy of the test point can be obtained according to the inlet steam temperature and inlet pressure of the test point, and then the difference between the outlet enthalpy and the inlet enthalpy is determined as the enthalpy increase of each pipe at the test point. In one embodiment of the present disclosure, the steam temperature of the inlet header can be obtained according to the existing test point, the function formula of the load of the inlet pressure of the heating surface, the feed water pressure and the main steam pressure can be calculated according to the thermal calculation formula, and the inlet pressure of the heating surface can be calculated according to the existing feed water pressure and the main steam pressure.

[0099] Furthermore, in one embodiment of the present disclosure, the method for calculating the enthalpy increase of each pipe without a measuring point is the same as the method for calculating the enthalpy increase of each pipe at the measuring point, and the present disclosure embodiment will not be described in detail herein.

[0100] And, in one embodiment of the present disclosure, the method for calculating the heat absorption of each tube of the platen superheater according to the flow rate of each tube of the heating surface and the inlet enthalpy and outlet enthalpy of each tube of the platen superheater may specifically include: based on the enthalpy increase of each tube and the flow rate of each tube of the heating surface, obtaining the heat absorption of each tube of the platen superheater by a fifth formula, wherein the fifth formula is:

[0101]

[0102] Among them, D ij is the flow rate of the jth tube of the i-th screen, B cal To calculate the fuel quantity, Q ij The heat absorbed by the i-th screen j tube h″ ij is the outlet enthalpy of the jth tube of the ith screen, h′ ij is the inlet enthalpy of the jth tube of the i-th screen.

[0103] Furthermore, in one embodiment of the present disclosure, the flue gas temperature and steam temperature of the heating surface can be obtained by a furnace acoustic wave temperature measuring device. The furnace acoustic wave temperature measuring device can be installed near the flame bending angle of the boiler furnace, arranged horizontally, and the furnace flue gas temperature field information can be obtained by the acoustic wave method.

[0104] In another embodiment of the present disclosure, a numerical simulation method can be used to implement a flue gas temperature data-driven model under different loads, and obtain the flue gas temperature and steam temperature of the heating surface. Specifically, in one embodiment of the present disclosure, a flunt simulation can be used to calculate the flue gas temperature at different cross-sections of the furnace under different loads. And, based on the knowledge of fluid mechanics, the mass conservation equation (continuity equation), the energy conservation equation (Bernoulli equation) and the momentum conservation equation (Navier-Stokes equation) are three equations that describe the flow phenomenon of ideal fluids. Based on this, through the above three equations, the required parameters (such as velocity, temperature and pressure) can be obtained at various points in a very complex flow field at a specific time, and other related physical quantities can be derived.

[0105] And, in one embodiment of the present disclosure, after the flue gas temperature and steam temperature of the heating surface are obtained through the above steps, the overall temperature and pressure average value of the heating surface can be obtained based on the flue gas temperature and steam temperature of the heating surface. Specifically, in one embodiment of the present disclosure, the method for obtaining the overall temperature and pressure average value of the heating surface based on the flue gas temperature and steam temperature of the heating surface may include: based on the flue gas temperature and steam temperature of the heating surface, obtaining the overall temperature and pressure average value of the heating surface through the sixth formula, wherein the sixth formula is:

[0106]

[0107] Among them, Δt max Δt is the maximum difference between the flue gas temperature and the steam temperature at both ends of the heating surface, in °C; min It is the smaller difference between the flue gas temperature and the steam temperature at both ends of the heating surface, in °C; Δt is the average temperature and pressure of the entire heating surface, in °C.

[0108] And, in one embodiment of the present disclosure, the method for obtaining the actual heat transfer coefficient of the heating surface based on the overall temperature and pressure average value of the heating surface and the heat absorption of each tube of the platen superheater may include: correcting the overall temperature and pressure average value of the heating surface to obtain a corrected overall temperature and pressure average value of the heating surface, and obtaining the actual heat transfer coefficient of the heating surface based on the corrected overall temperature and pressure average value of the heating surface and the heat absorption of each tube of the platen superheater.

[0109] In one embodiment of the present disclosure, the method for correcting the overall average temperature and pressure of the heating surface to obtain the corrected overall average temperature and pressure of the heating surface may include: correcting the overall average temperature and pressure of the heating surface by the seventh formula to obtain the corrected overall average temperature and pressure of the heating surface, wherein the seventh formula is:

[0110]

[0111] Among them, Q gz It's Q ij The average value, m is the total number of screens, n is the total number of tubes, T a is the inertia time constant of the heating surface under deep peak load conditions, K is the real-time overall heat transfer coefficient of the heating surface, KW / (m2*℃); Δt cp is the corrected average temperature and pressure of the entire heated surface, in °C; s is the independent variable corresponding to the transfer function. The system transfer function corresponds to the differential equation that describes its motion law.

[0112] And, in one embodiment of the present disclosure, the above-mentioned correction of the overall temperature and pressure average value of the heating surface can better meet the influence of the furnace flue gas temperature on the heat transfer of the heating surface and the influence of the deep peak-shaving operation condition on the heat transfer of the heating surface.

[0113] Further, in one embodiment of the present disclosure, the method for obtaining the actual heat transfer coefficient of the heating surface based on the corrected average temperature and pressure of the entire heating surface and the heat absorption of each tube of the platen superheater may include: obtaining the actual heat transfer coefficient of the heating surface through an eighth formula based on the corrected average temperature and pressure of the entire heating surface and the heat absorption of each tube of the platen superheater, wherein the eighth formula is:

[0114]

[0115] Among them, H 受热面积 is the heating surface area, k sj Is the actual heat transfer coefficient of the heated surface, KW / (m2*℃).

[0116] Step 104: Calculate the ideal heat transfer coefficient of the heating surface according to the heat transfer principle of the heating surface.

[0117] In one embodiment of the present disclosure, according to the heat transfer principle of the heated surface, the ideal heat transfer coefficient of the heated surface is calculated by the ninth formula, wherein the ninth formula is:

[0118]

[0119] Among them, a d is the heat transfer coefficient of the heated surface, in KW / (m2*℃); a fk is the radiation heat release coefficient of the heated surface, the unit is KW / (m2*℃); lx It is the ideal heat release coefficient of the heating surface, and its unit is KW / (m2*℃).

[0120] Step 105: Obtain a heating surface cleanliness factor according to the actual heat transfer coefficient of the heating surface and the ideal heat transfer coefficient of the heating surface, and monitor the contamination state of the platen superheater tube by using the heating surface cleanliness factor.

[0121] Among them, in one embodiment of the present disclosure, after obtaining the actual heat transfer coefficient of the heating surface and the ideal heat transfer coefficient of the heating surface through the above steps, the cleaning factor of the heating surface can be obtained according to the actual heat transfer coefficient of the heating surface and the ideal heat transfer coefficient of the heating surface.

[0122] Specifically, in one embodiment of the present disclosure, the method for obtaining the heating surface cleanliness factor based on the actual heat transfer coefficient of the heating surface and the ideal heat transfer coefficient of the heating surface may include: determining the ratio of the actual heat transfer coefficient of the heating surface to the ideal heat transfer coefficient of the heating surface as the heating surface cleanliness factor.

[0123] Further, in one embodiment of the present disclosure, after obtaining the heating surface cleaning factor through the above steps, the method for monitoring the contamination state of the platen superheater tube through the heating surface cleaning factor may include: if the heating surface cleaning factor is in a first interval range, the platen superheater tube is in a first state; if the heating surface cleaning factor is in a second interval range, the platen superheater tube is in a second state; if the heating surface cleaning factor is in a third interval range, the platen superheater tube is in a third state. The first state may be a serious dust accumulation state, the second state may be a dust accumulation state requiring cleaning, and the third state may be a normal ideal state.

[0124] For example, in one embodiment of the present disclosure, the range of the heated surface cleaning factor is [0, 1], the first interval range is [0, 0.5), the second interval range is [0.5, 0.7), and the third interval range is [0.7, 1]. Assuming that the current value of the heated surface cleaning factor is 0.6, the current heated surface cleaning factor is in the second interval range, indicating that the dust is accumulated and needs to be cleaned.

[0125] In summary, the method for monitoring the contamination status of the platen superheater tube of an ultra-supercritical boiler provided by the present application obtains the first historical data of the DCS / SIS system within a preset time and the second historical data of the test point of the platen superheater tube within a preset time; based on the first historical data, the third historical data of the platen superheater tube without a test point is obtained by calculation; based on the structural parameters of the platen superheater, the second historical data and the third historical data, the actual heat transfer coefficient of the heating surface is obtained by calculation; based on the heat transfer principle of the heating surface, the ideal heat transfer coefficient of the heating surface is calculated; based on the actual heat transfer coefficient of the heating surface and the ideal heat transfer coefficient of the heating surface, the heating surface cleanliness factor is obtained, and the contamination status of the platen superheater tube is monitored by the heating surface cleanliness factor. Therefore, the historical data required by the present disclosure is convenient to collect, and there is no need to install additional instruments and equipment, which reduces costs, and the real-time monitoring of the contamination status of the platen superheater is realized through the heating surface cleanliness factor, which ensures the reliability of the calculated values ​​of the contamination factors of different parts of the platen superheater.

[0126] Figure 2 A schematic diagram of a device for monitoring the contamination status of a platen superheater tube of an ultra-supercritical boiler according to an embodiment of the present application is shown in FIG. Figure 2 As shown, the device may include:

[0127] An acquisition module 201 is used to acquire first historical data of a DCS / SIS system within a preset time and second historical data of a test point of a platen superheater tube within a preset time;

[0128] A first calculation module 202 is used to obtain third historical data of the platen superheater tube without measuring points by calculation according to the first historical data;

[0129] The second calculation module 203 is used to obtain the actual heat transfer coefficient of the heating surface by calculation according to the structural parameters of the platen superheater, the second historical data and the third historical data;

[0130] The third calculation module 204 is used to calculate the ideal heat transfer coefficient of the heating surface according to the heat transfer principle of the heating surface;

[0131] The monitoring module 205 is used to obtain a heating surface cleanliness factor according to the actual heat transfer coefficient of the heating surface and the ideal heat transfer coefficient of the heating surface, and monitor the contamination state of the platen superheater tube through the heating surface cleanliness factor.

[0132] In one embodiment of the present disclosure, the first historical data includes outlet steam temperature, outlet pressure, inlet steam temperature and inlet pressure; the first calculation module 202 is specifically used to:

[0133] Calculate outlet enthalpy based on outlet steam temperature and outlet pressure;

[0134] Calculate the inlet enthalpy based on the inlet steam temperature and inlet pressure;

[0135] According to the outlet enthalpy and the inlet enthalpy, calculate the inter-screen thermal deviation coefficient and the same-screen thermal deviation coefficient;

[0136] According to the inter-screen thermal deviation coefficient and the same-screen thermal deviation coefficient, calculate the enthalpy increase of the heated surface without measuring points;

[0137] According to the enthalpy increase of the heating surface, the outlet steam temperature of the platen superheater tube without measuring point is obtained by calculation.

[0138] Further, in one embodiment of the present disclosure, the second calculation module 203 is specifically used to:

[0139] According to the structural parameters of the platen superheater, the flow rate of each pipe on the heating surface is obtained;

[0140] According to the flow rate of each pipe on the heating surface, the second historical data and the third historical data, the heat absorption of each pipe of the platen superheater is obtained by calculation;

[0141] Obtain the flue gas temperature and steam temperature of the heating surface, and based on the flue gas temperature and steam temperature of the heating surface, obtain the average temperature and pressure of the entire heating surface;

[0142] Based on the average temperature and pressure of the heating surface and the heat absorption of each tube of the platen superheater, the actual heat transfer coefficient of the heating surface is obtained.

[0143] Furthermore, in one embodiment of the present disclosure, the second calculation module 203 is further configured to:

[0144] Correcting the average value of the overall temperature and pressure of the heating surface to obtain a corrected average value of the overall temperature and pressure of the heating surface;

[0145] Based on the corrected average temperature and pressure of the heating surface and the heat absorption of each tube of the platen superheater, the actual heat transfer coefficient of the heating surface is obtained.

[0146] Furthermore, in one embodiment of the present disclosure, the second calculation module 203 is further configured to:

[0147] According to the second historical data and the third historical data, the inlet enthalpy and the outlet enthalpy of each tube of the platen superheater are obtained;

[0148] According to the flow rate of each tube on the heating surface and the inlet enthalpy and outlet enthalpy of each tube of the platen superheater, the heat absorption of each tube of the platen superheater is obtained by calculation.

[0149] Furthermore, in one embodiment of the present disclosure, the monitoring module 205 is specifically used to:

[0150] The ratio of the actual heat transfer coefficient of the heating surface to the ideal heat transfer coefficient of the heating surface is determined as the cleaning factor of the heating surface.

[0151] Furthermore, in one embodiment of the present disclosure, the monitoring module 205 is specifically used to:

[0152] If the heating surface cleanliness factor is in the first interval range, the platen superheater tube is in the first state;

[0153] If the heat cleaning factor is in the second interval, the platen superheater tube is in the second state;

[0154] If the heat cleaning factor is in the third interval range, the platen superheater tube is in the third state.

[0155] In summary, the ultra-supercritical boiler platen superheater tube contamination status monitoring device provided by the present application obtains the first historical data of the DCS / SIS system within a preset time and the second historical data of the test point of the platen superheater tube within a preset time; according to the first historical data, the third historical data of the platen superheater tube without a test point is obtained by calculation; according to the structural parameters of the platen superheater, the second historical data and the third historical data, the actual heat transfer coefficient of the heating surface is obtained by calculation; according to the heat transfer principle of the heating surface, the ideal heat transfer coefficient of the heating surface is calculated; according to the actual heat transfer coefficient of the heating surface and the ideal heat transfer coefficient of the heating surface, the heating surface cleanliness factor is obtained, and the contamination status of the platen superheater tube is monitored by the heating surface cleanliness factor. Therefore, the historical data required by the present disclosure is convenient to collect, and there is no need to install additional instruments and equipment, which reduces costs, and the heating surface cleanliness factor is used to realize real-time monitoring of the contamination status of the platen superheater, ensuring the reliability of the calculated values ​​of the contamination factors of different parts of the platen superheater.

[0156] In order to implement the above embodiments, the present disclosure also proposes a computer storage medium.

[0157] The computer storage medium provided in the embodiment of the present disclosure stores an executable program; after the executable program is executed by the processor, the following can be achieved: Figure 1 The method shown.

[0158] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. 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 application. In this specification, the schematic representations of the above terms do 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. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0159] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0160] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A method for monitoring the contamination status of ultra-supercritical boiler platen superheater tubes, characterized in that: The method comprises: Acquire first historical data of the DCS / SIS system within a preset time and second historical data of the point to be measured of the platen superheater tube within the preset time, wherein the first historical data includes outlet steam temperature, outlet pressure, inlet steam temperature and inlet pressure, and the second historical data includes outlet steam temperature of the point to be measured, outlet pressure of the point to be measured and steam flow rate of the point to be measured; According to the first historical data, third historical data of the platen superheater tube without measuring points is obtained by calculation, wherein the third historical data includes the outlet steam temperature without measuring points; According to the structural parameters of the platen superheater, the second historical data and the third historical data, an actual heat transfer coefficient of the heating surface is obtained by calculation; According to the heat transfer principle of the heated surface, the ideal heat transfer coefficient of the heated surface is calculated; According to the actual heat transfer coefficient of the heating surface and the ideal heat transfer coefficient of the heating surface, a heating surface cleanliness factor is obtained, and the contamination state of the platen superheater tube is monitored by the heating surface cleanliness factor.

2. The method according to claim 1, characterized in that The method of obtaining the third historical data of the platen superheater tube without measuring points by calculation according to the first historical data includes: calculating outlet enthalpy based on the outlet steam temperature and the outlet pressure; calculating an inlet enthalpy based on the inlet steam temperature and the inlet pressure; Calculating the inter-screen thermal deviation coefficient and the same-screen thermal deviation coefficient according to the outlet enthalpy and the inlet enthalpy; Calculating the enthalpy increase of the heated surface without measuring points according to the inter-screen thermal deviation coefficient and the same-screen thermal deviation coefficient; According to the enthalpy increase of the heating surface, the outlet steam temperature of the platen superheater tube without measuring point is obtained by calculation.

3. The method according to claim 1, characterized in that The actual heat transfer coefficient of the heating surface is obtained by calculation according to the structural parameters of the platen superheater, the second historical data and the third historical data, including: According to the structural parameters of the platen superheater, the flow rate of each pipe on the heating surface is obtained; According to the flow rate of each tube of the heating surface, the second historical data and the third historical data, the heat absorption amount of each tube of the platen superheater is obtained by calculation; Obtaining the flue gas temperature and steam temperature of the heating surface, and obtaining the average value of the overall temperature and pressure of the heating surface based on the flue gas temperature and steam temperature of the heating surface; Based on the average value of the overall temperature and pressure of the heating surface and the amount of heat absorbed by each tube of the platen superheater, the actual heat transfer coefficient of the heating surface is obtained.

4. The method according to claim 3, characterized in that: The actual heat transfer coefficient of the heating surface is obtained based on the average value of the overall temperature and pressure of the heating surface and the heat absorption of each tube of the platen superheater, including: Correcting the average value of the overall temperature and pressure of the heating surface to obtain a corrected average value of the overall temperature and pressure of the heating surface; Based on the corrected average value of the overall temperature and pressure of the heating surface and the amount of heat absorbed by each tube of the platen superheater, the actual heat transfer coefficient of the heating surface is obtained.

5. The method according to claim 3, characterized in that: The heat absorption amount of each tube of the platen superheater is obtained by calculation according to the flow rate of each tube of the heating surface, the second historical data and the third historical data, including: According to the second historical data and the third historical data, the inlet enthalpy and the outlet enthalpy of each tube of the platen superheater are obtained; According to the flow rate of each tube of the heating surface and the inlet enthalpy and outlet enthalpy of each tube of the platen superheater, the heat absorption of each tube of the platen superheater is obtained by calculation.

6. The method according to claim 1, characterized in that Obtaining the heating surface cleaning factor according to the actual heat transfer coefficient of the heating surface and the ideal heat transfer coefficient of the heating surface includes: determining the ratio of the actual heat transfer coefficient of the heating surface to the ideal heat transfer coefficient of the heating surface as the heating surface cleaning factor.

7. The method according to claim 1, characterized in that The monitoring of the contamination state of the platen superheater tube by the heating surface cleaning factor includes: If the heating surface cleaning factor is in the first interval range, the platen superheater tube is in the first state; If the heating surface cleaning factor is in the second interval range, the platen superheater tube is in the second state; If the heating surface cleaning factor is in the third interval range, the platen superheater tube is in the third state.

8. An ultra-supercritical boiler platen superheater tube contamination status monitoring device, characterized in that: The device comprises: An acquisition module, used to acquire first historical data of a DCS / SIS system within a preset time and second historical data of a point to be measured of a platen superheater tube within the preset time, wherein the first historical data includes outlet steam temperature, outlet pressure, inlet steam temperature and inlet pressure, and the second historical data includes outlet steam temperature of the point to be measured, outlet pressure of the point to be measured and steam flow rate of the point to be measured; A first calculation module is used to obtain third historical data of the platen superheater tube without measuring points by calculation according to the first historical data, wherein the third historical data includes an outlet steam temperature without measuring points; A second calculation module is used to obtain an actual heat transfer coefficient of a heating surface by calculation according to the structural parameters of the platen superheater, the second historical data and the third historical data; The third calculation module is used to calculate the ideal heat transfer coefficient of the heating surface according to the heat transfer principle of the heating surface; The monitoring module is used to obtain a heating surface cleanliness factor according to the actual heat transfer coefficient of the heating surface and the ideal heat transfer coefficient of the heating surface, and monitor the contamination state of the platen superheater tube through the heating surface cleanliness factor.

9. An electronic device comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the method according to any one of claims 1 to 7.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for monitoring the contamination status of the platen superheater tube of an ultra-supercritical boiler as described in any one of claims 1 to 7 is implemented.

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