A device and method for monitoring the corrosion rate of a refractory brick layer

Abstract

The present invention discloses a erosion rate monitoring device and a monitoring method for a refractory brick layer. The erosion rate monitoring device for a refractory brick layer includes a data acquisition module connected to a furnace body to be monitored, and also includes data processing modules I, II and III; both modules I and II are used to calculate the temperature T, flow velocity u and thickness δ of the liquid slag layer; module III is a erosion rate calculation module, module I is used to obtain the data parameters required in module III by establishing a multiphase turbulent reaction flow database in the furnace body and using an interpolation algorithm; module I is connected to module III, and is used to transmit the calculated data parameters to module III; module II is used to establish energy conservation, mass conservation and momentum equations. The monitoring device of the present invention can realize continuous online monitoring of the erosion rate of the refractory brick layer.

Description

Technical Field

[0001] The invention relates to a device and method for monitoring the corrosion rate of a refractory brick layer. Background Art

[0002] Coal gasification technology is a process for preparing clean syngas (a mixture of CO and H2) by partial oxidation of coal with gasifying agents under certain temperature and pressure conditions. It is one of the main ways to cleanly convert coal. Entrained-bed coal gasification technology represents the development trend of future coal gasification technology because of its advantages such as large processing load, high pressure and no tar. It is also the cleanest technology and the main technology used in coal utilization.

[0003] Entrained-bed gasification technology is divided into water-coal slurry gasification technology and dry coal powder gasification technology according to the feeding method. According to the thermal insulation lining structure of the gasifier, it can be divided into refractory brick-lined gasifiers (such as: multi-nozzle water-coal slurry gasifiers, GE gasifiers, CBI gasification technology) and water-cooled wall-lined gasifiers (such as: Shell furnace, GSP furnace), etc. The coal gasification technology using water-coal slurry as raw material generally adopts refractory brick-lined gasifiers, and the gasification technology using pulverized coal as raw material generally adopts water-cooled wall-lined gasifiers. The water-coal slurry refractory brick-lined gasification technology has been widely used in the field of coal gasification abroad due to its advantages such as short process flow, simple gasifier structure, small heat loss, and high chemical energy conversion rate. The thickness of refractory bricks is one of the key parameters of the gasifier structure. During the operation of the gasifier, the refractory bricks are gradually corroded and thinned under the erosion of high-temperature slag. When the thickness of the refractory bricks is less than a certain critical value, the thermal insulation effect is greatly reduced, and the metal shell of the gasifier overheats, which directly affects the safety of the metal shell of the gasifier. The service life of refractory bricks in local areas of existing gasifiers is only 3-8 months depending on the furnace structure. In addition, the service life is also affected by many factors such as the operating temperature of the gasifier, coal quality, furnace structure, refractory material properties and refractory brick masonry quality.

[0004] So far, there is no technology or method to measure and monitor the erosion rate or status of refractory bricks in industrial gasifiers. The thickness and status monitoring of existing refractory brick gasifiers are based on the empirical judgment of the surface temperature of the metal shell of the gasifier. When the metal wall temperature is higher than the empirical value, it is stopped and cooled and then manually inspected and measured. Since the wall temperature is greatly affected by the measurement accuracy and environmental factors, the empirical judgment method based on the wall temperature has a large error, and even misjudgment may occur, which directly reduces the online rate and economy of the device system.

[0005] Therefore, there is an urgent need to develop a real-time online monitoring device and monitoring method for the state inside the gasifier. Summary of the invention

[0006] The technical problem to be solved by the present invention is to overcome the defect of the lack of effective monitoring of the state of refractory bricks in the water-coal slurry gasifier in the prior art, and to provide a refractory brick layer erosion rate monitoring device and monitoring method. The present invention accurately measures the outer wall temperature of the metal wall and realizes rapid measurement, combines the composition and metering data of raw coal used in industrial production, and adopts a combination of mechanism and intelligence to continuously monitor the erosion rate of the refractory brick layer in the gasifier online.

[0007] The present invention solves the above technical problems through the following technical solutions:

[0008] A device for monitoring the corrosion rate of a refractory brick layer, comprising a data processing module and a data acquisition module connected to a furnace body to be monitored;

[0009] The furnace body to be monitored includes a liquid slag layer, a refractory brick layer and a metal wall from the inside to the outside, and the refractory brick layer includes a fire-facing brick layer, a backing brick layer and an insulating brick layer from the inside to the outside;

[0010] The data acquisition module is used to collect and measure the working condition data of the furnace body to be monitored required by the data processing module during calculation and operation. The data acquisition module is electrically connected to the data processing module and is used to transmit the obtained working condition data to the data processing module.

[0011] The data processing module includes a data processing module I, a data processing module II and a data processing module III; the data processing module I and the data processing module II are respectively used to calculate the temperature T1 and T2 of the liquid slag layer, the flow speed u1 and u2 of the liquid slag layer, and the thickness δ1 and δ2 of the liquid slag layer; the data processing module III is a module for calculating the erosion rate of the liquid slag layer, and its calculation formula is shown as follows:

[0012] C is the model constant of the liquid slag layer, η s is the viscosity of the liquid slag layer;

[0013] Substituting the data parameters obtained by the data processing module I and the data processing module II into the calculation formula of the data processing module III, respectively obtaining the erosion rates J1 and J2 of the liquid slag layer; taking the average value of J1 and J2, which is the erosion rate of the refractory brick layer;

[0014] The data processing module I is used to establish a multiphase turbulent reaction flow database and "the operating condition data of the furnace to be monitored acquired and measured by the data acquisition module" according to the computational fluid dynamics method, and to calculate the T1, the u1 and the δ1 using an interpolation algorithm; the data processing module I is electrically connected to the data processing module III, and is used to transmit the calculated data parameters to the data processing module III;

[0015] The data processing module II is used to establish the energy conservation equation between the metal wall, the refractory brick layer and the liquid slag layer, and then substitute the heat flux density formula that passes through the metal wall, the refractory brick layer and the liquid slag layer in sequence to calculate T2. It is also used to establish the mass conservation equation and the momentum equation in the flow heat transfer process of the liquid slag layer, and jointly solve and calculate to obtain δ2 and u2; the data processing module II is electrically connected to the data processing module III, and is used to transmit the calculated data parameters to the data processing module III.

[0016] The data processing module I of the present invention uses the multiphase turbulent reaction flow database established by the computational fluid dynamics method and combines it with the interpolation algorithm to calculate the T1, u1 and δ1 data sets. Then, the data processing module II is combined to calculate T2, u2 and δ2, and the two sets of data are substituted into the data processing module III to calculate J1 and J2. By calculating the average value, the online real-time monitoring of the erosion rate of the refractory brick layer is realized.

[0017] In the present invention, the furnace to be monitored may be conventional in the art, preferably a gasification furnace.

[0018] In the present invention, the viscosity of the liquid slag layer is the basic physical property data, which can be obtained by conventional methods in the art, generally by analytical testing, or can be predicted based on the ash composition in coal. The calculation rule of the liquid slag layer is generally: η s =ae bT , a and b are functions of the ash content, and T is the temperature of the liquid slag layer; its value is related to the temperature distribution of the liquid slag layer and is calculated through the viscosity-temperature characteristic curve of the slag and the temperature of the liquid slag layer.

[0019] In the present invention, the model constant of the liquid slag layer may have the meaning commonly understood in the art, and is generally determined according to the structural parameters of the refractory brick layer, and the value range may be (0.1 to 100)*10 -3 , preferably (1-10)*10 -3 , preferably 3.55*10 -3 .

[0020] In the present invention, the working condition data of the furnace to be monitored may have the meaning commonly understood in the art, and is generally the experimental parameters related to the furnace to be monitored when the furnace to be monitored is working, such as coal slurry flow, coal quality composition, oxygen flow in the furnace to be monitored, ambient temperature of the outer wall surface close to the metal wall and the outer wall surface temperature of the metal wall, and operating pressure of the furnace to be monitored.

[0021] In the present invention, the data to be collected by the data collection module can be reasonably selected according to the data processing modules I, II and III. Preferably, it includes a coal slurry flow measurement component, a coal quality composition collection component, an oxygen flow measurement component and a temperature measurement component.

[0022] In the present invention, coal refers to the carbon-containing material entering the furnace to be monitored. After gasification, the combustible components of the coal are converted into gas phase, and the mineral components (ie, ash components) are converted into the liquid slag layer.

[0023] The coal slurry flow measurement component is preferably used to measure the coal slurry flow in the coal slurry conveying pipeline, and the coal slurry flow measurement component is electrically connected to the data processing module I, and is used to transmit the measured coal slurry flow to the data processing module I. The coal slurry conveying pipeline can be conventional in the art, and is generally used to convey coal required for gasification into the furnace body to be monitored, and is located on a pipeline connected to the nozzle of the furnace body to be monitored.

[0024] The coal slurry flow measurement component is also used to obtain the amount of coal entering the furnace body to be monitored (referred to as the coal entering the furnace amount). The coal slurry flow measurement component is electrically connected to the data processing module II and is used to transmit the obtained coal amount data entering the furnace body to be monitored to the data processing module II.

[0025] The coal slurry flow measurement component can be a conventional flow measurement device in the art. Preferably, the measurement mode of the coal slurry flow measurement component is online continuous measurement. The coal slurry flow measurement component is preferably located on the coal slurry conveying pipeline.

[0026] Wherein, the coal quality composition acquisition component is preferably used to measure the content of C element, H element, O element, N element, S element, ash content and ash composition in the coal in the coal slurry conveying pipeline. Preferably, the coal quality composition acquisition component is electrically connected to the data processing module I, and is used to transmit the measured content of C element, H element, O element, N element, S element, ash content and ash composition in the coal to the data processing module I. Preferably, the coal quality composition acquisition component is also electrically connected to the data processing module II, and is used to transmit the measured ash content to the data processing module II.

[0027] The coal quality composition collection component can be a conventional component measuring device in the art. The collection mode of the coal quality composition collection component can be offline collection or online collection. The offline collection generally refers to manual measurement after sampling the coal slurry. Preferably, the collection mode of the coal quality composition collection component is online collection. Preferably, the coal quality composition collection component is an online collector. The online collector is used to obtain real-time online coal ash data. The coal quality composition collection component is preferably located on the coal slurry conveying pipeline.

[0028] Among them, the oxygen flow measurement component is preferably used to measure the oxygen flow delivered to the furnace body to be monitored, and the oxygen flow measurement component is electrically connected to the data processing module I for transmitting the measured oxygen flow to the data processing module I.

[0029] Among them, the temperature measuring component is preferably used to measure the outer wall temperature of the metal wall and the ambient temperature close to the outer wall surface of the metal wall. The temperature measuring component is electrically connected to the data processing module II for transmitting the measured data to the data processing module II.

[0030] The temperature measuring component can be a conventional device for measuring temperature in the art, preferably an infrared thermal imager or a thermocouple. When the temperature measuring component is the thermocouple, the thermocouple is preferably arranged on the outer surface of the metal wall, and the arrangement density of the thermocouple is preferably 1 to 4 / m 2 . When the temperature measuring component is the infrared thermal imager, preferably, the infrared thermal imager is arranged so that the viewing angle of the infrared thermal imager covers the outer surface of the metal wall. The ambient temperature may be the meaning conventionally understood in the art, generally referring to the gas temperature near the outer wall surface of the metal wall. When measuring the ambient temperature, the shortest distance between the temperature measuring component and the outer wall surface of the metal wall is preferably 0.01m to 5m, more preferably 50cm.

[0031] The outer wall temperature of the metal wall is preferably measured by the following measurement system: it includes an infrared thermal imager assembly arranged on the outer surface of the furnace body to be monitored; the furnace body to be monitored includes a dome and a straight section of the cylinder; the infrared thermal imager assembly includes a first infrared thermal imager group distributed above the dome, and a second infrared thermal imager group distributed horizontally and circumferentially on the straight section of the cylinder; the second infrared thermal imager group includes A layers arranged in parallel, and B infrared thermal imagers in each layer; the number of layers of the A layer is given by the formula The integer calculated; the number of B is given by the formula The calculated integer; D is the outer diameter of the straight section of the cylinder, H is the height of the straight section of the cylinder, and a is the viewing angle of the infrared thermal imager; in the second infrared thermal imager group, the distance between each infrared thermal imager and the outer surface of the furnace body to be measured is L, and L is the vertical distance from each infrared thermal imager to the central axis of the furnace body to be measured minus the radius of the furnace body to be measured; the relationship between L and D is: 0.5D≤L≤5D. Preferably, a is 20 to 84°, such as 30°, 50° or 60°, and a refers to the angle between the surface of the sensor on the infrared thermal imager and the center of the lens; the total number of the second infrared thermal imager group is the value of A multiplied by B. The relationship between L and D is: 1D≤L≤2D. The above-mentioned temperature measurement system for the outer wall surface of the metal wall realizes more accurate measurement, which is more conducive to real-time online calculation of the erosion rate of the refractory brick layer.

[0032] In the present invention, the furnace body to be monitored is, for example, a multi-nozzle gasification furnace or a single-nozzle gasification furnace with a capacity of 1000 to 4000 tons / day.

[0033] In the present invention, in the data processing module I, the multiphase turbulent reaction flow database preferably includes the gas temperature distribution near the inner wall surface in the furnace of the furnace body to be monitored, the gas flow velocity in the furnace body to be monitored, the gas concentration in the furnace body to be monitored, the liquid slag deposition distribution on the inner wall surface of the fire face brick layer and the flow data parameters of the slag in the slag layer.

[0034] Wherein, the multiphase turbulent reaction flow database is preferably established by using computational fluid dynamics (CFD) method according to the operating condition data transmitted by the data acquisition module.

[0035] In the present invention, the interpolation algorithm preferably adopts a neural network algorithm or a kriging interpolation method, and more preferably a neural network algorithm.

[0036] In the present invention, those skilled in the art know that the interpolation algorithm generally includes the following process: a mapping relationship is established between a multiphase turbulent reaction flow database and the operating condition data transmitted from the data acquisition module to the data processing module I according to a computational fluid dynamics method to obtain a basic mapping model, and then the operating condition data transmitted from the data acquisition module to the data processing module I is used as the input of the interpolation algorithm and combined with the basic mapping model to calculate T1, u1 and δ1.

[0037] In the present invention, the data processing module I can preferably also calculate the following parameters: the concentration of gas components in the furnace to be monitored, carbon conversion rate, gas flow velocity and turbulence intensity, particle velocity distribution, and particle concentration distribution. The gas components include, for example, one or more of CO, H2, CO2, and H2O.

[0038] In the present invention, in the data processing module II, the calculation method of the heat conservation of heat transfer can be conventional in the field, generally, the heat flux density passing through the metal wall is first calculated according to the temperature of the outer wall surface of the metal wall and the ambient temperature, and then the calculated heat flux density is substituted into the calculation formula of the heat flux density of each layer of the refractory brick layer to calculate the thickness of each layer of the refractory brick layer, and then the temperature distribution of each layer of the refractory brick layer is calculated according to the energy conservation equation, and then the temperature of the liquid slag layer is obtained.

[0039] The calculation formula of the heat flux density passing through the metal wall can be:

[0040] q out,i =2πΔzr0(T m,i -T air )h air,i , T m,i is the temperature of the outer wall of the metal wall, T air is the ambient temperature, h air,i is the convection heat transfer coefficient between the outer wall of the metal wall and the atmosphere, △z is the height of the fire-facing brick layer; h air,i according to Calculated, h conv is the natural convection constant, and c is the constant of the metal wall.

[0041] The calculation formula of the heat flux density passing through each layer of the refractory brick layer can be:

[0042]

[0043] T g,i The temperature of the gas near the inner wall surface in the furnace of the furnace body to be monitored;

[0044] The calculated r j Substitute into the following formula to calculate the thickness of each layer:

[0045] r2=r1-δ r,c ,r3=r2-δ r,1 ,r4=r3-δ r,2 ,r5=r4-δ r,3 ,r6=r5-δ s,i; r5 is the inner diameter of the fire-facing brick layer, r6 is the inner diameter of the liquid slag layer, r4 is the inner diameter of the backing brick layer, and r3 is the inner diameter of the insulation brick layer;

[0046] k r,1 ,k r,2 ,k r,3 ,k s,i The thermal conductivity of the insulating brick layer, the backing brick layer, the fire-facing brick layer and the liquid slag layer are obtained by querying the physical property parameters; the calculation rule of the slag thermal conductivity calculation module is: k s =k s,i is the thermal conductivity of the liquid slag layer, k1 is a function of the ash content, k2 is a function of the ash content, and T is the temperature of the slag in the slag layer;

[0047] δ r,1 ,δ r,2 ,δ r,3 and δ s,i They are respectively the thickness of the heat insulating brick layer, the thickness of the backing brick layer, the thickness of the fire facing brick layer and the thickness of the liquid slag layer.

[0048] The calculation formula of the energy conservation equation may be:

[0049] q out，i ×A m =q ref1 ×A r1 =q ref2 ×A r2 =q ref3 ×A r3 =q refs ×A s ,q out,i ,q ref1 ,q ref2 ,q ref3 ,q refs are the heat flux densities passing through the metal wall, the insulating brick layer, the backing brick layer, the fire-facing bricks and the liquid slag layer, respectively. m , A r1 , A r2 , A r3 , A s They refer to the radial heat transfer areas of the metal wall, the insulating brick layer, the backing brick layer, the fire-facing brick layer and the liquid slag layer, respectively, and the temperature of the liquid slag layer is obtained;

[0050] In the present invention, in the data processing module II, it is assumed that 70wt.% of the coal added to the gasifier is deposited on the inner wall of the fire-facing brick layer after the gasification reaction to form the liquid slag layer, and the distribution is uniform. The slag flow in the liquid slag layer satisfies the Newtonian fluid flow. The mass conservation equation established for the flow heat transfer process of the liquid slag layer is generally as follows: δ s,i It refers to the thickness of the liquid slag layer, in m; ρ s is the density of the liquid slag layer; m in,j is the amount of slag deposited on the inner wall of the furnace to be monitored, in kg, and its value is m in,j = mass of carbon-containing material entering the furnace (generally refers to the amount of coal entering the furnace) × ash content × 70%; L i is the equivalent circumference of the straight section of the cylinder in the furnace to be monitored, in m; x is the displacement of the particle in the liquid slag layer; i is the coordinate identifier of the position of the point, j is the coordinate range from the top of the furnace to be monitored to the i point, and the physical meaning is that the slag amount at the i-th point is the sum of all deposited particles from the top to the i point;

[0051] In the present invention, in the data processing module II, the momentum equation is:

[0052] The boundary conditions are v i (x) is the velocity distribution function in the liquid slag layer, η s is the viscosity of the liquid slag layer, v is the flow velocity of the liquid slag layer, g is the gravitational acceleration, β is the inclination angle of the slag flowing on the inner wall surface of the furnace body to be monitored, ρ s refers to the density of the liquid slag layer, τ is the shear force on the inner wall of the furnace to be monitored; τ = 0.0303ρ g u0 2 ρ g It refers to the density of the synthesis gas in the furnace to be monitored, u0 2 refers to the surface velocity of the liquid slag layer; r g Calculated based on gasifier type, temperature and pressure.

[0053] In the present invention, the flow velocity of the liquid slag layer is preferably 0.001-0.05 m / s.

[0054] In the present invention, the thickness of the liquid slag layer is preferably less than 8 mm.

[0055] In the present invention, preferably, the data processing module also includes a liquid slag layer erosion accumulation initialization and integrator, which is used for the cumulative calculation of the erosion thickness of the refractory brick layer and the calculation of the remaining thickness of the refractory brick layer. The use process of the liquid slag layer erosion accumulation initialization and integrator is as follows: when a new refractory brick layer is installed, the initialization refractory brick layer thickness at this time is M, when the furnace to be monitored is operated at temperature T and load Q for time t, the erosion rate J is calculated, and the data is input into the integrator, then the remaining thickness is M(t)=MJ*t.

[0056] In the present invention, the data processing module preferably further includes a verification module, the verification module is electrically connected to the data processing module III, and the verification module is used to obtain the average value of J1 and J2. Those skilled in the art know that the verification module will discard abnormal values ​​after mutual verification before taking the average value. The verification module is also used to verify the data obtained by the initialization of the accumulated erosion of the liquid slag layer and the calculation of the integrator.

[0057] In the present invention, the monitoring device preferably also includes a data transmission module.

[0058] The data transmission module transmits the data signal to the acquisition card or the central control system DCS, and then transmits it to the data processing module using a certain data transmission protocol. The data transmission module can be a conventional device capable of transmitting signals in the art. Generally, the data transmission module is a cable or a data line. The data transmission protocol can be conventional in the art. Preferably, the data transmission protocol is TCPIP, Webservice or UDP.

[0059] Furthermore, the present invention can determine whether the slag outlet is blocked by slag in combination with the slag outlet size of the gasifier, thereby providing theoretical guidance for the operation of the gasifier.

[0060] The present invention also provides a method for monitoring the erosion rate of a refractory brick layer, which uses the erosion rate monitoring device for the refractory brick layer and comprises the following steps:

[0061] (1) using the data acquisition module to collect data;

[0062] (2) The data in step (1) is transferred to the data processing module for calculation and processing.

[0063] In the present invention, the data collected by the data collection module preferably include the temperature of the outer wall surface of the metal wall, the ambient temperature, the coal slurry flow in the coal slurry conveying pipeline, ash composition and ash content, oxygen flow and coal slurry concentration.

[0064] On the basis of being in accordance with the common sense in the art, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present invention.

[0065] The positive progress of the present invention is that the present invention measures the temperature of the outer wall surface of the metal wall, combines the composition and metering data of the raw material coal in industrial production, and adopts a combination of mechanism and intelligence to continuously monitor the temperature of the furnace body to be monitored, the thickness of the refractory brick layer, and other states online, and can monitor the temperature distribution, thickness, flow velocity of the refractory brick layer, and the erosion rate distribution of the refractory brick layer. The monitoring results obtained by the present invention are accurate and comprehensive. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 This is a schematic diagram of the slag flow and heat transfer principle in the gasifier in Example 1.

[0067] Figure 2 This is a flow chart of the calculation principle in Example 1.

[0068] Figure 3 This is a calculation flow chart of the neural network algorithm in Example 1.

[0069] Figure 4 It is a graph of the erosion rate of the refractory brick layer of the gasifier measured in real time online in Example 1, wherein the horizontal axis is the ratio of the height of the straight section of the cylinder of the gasifier to the outer diameter of the straight section of the cylinder, and the vertical axis is the erosion rate of the refractory brick layer.

[0070] Explanation of reference numerals: 1-liquid slag layer, 2-refractory brick layer, 3-metal wall DETAILED DESCRIPTION

[0071] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples. The experimental methods in the following examples without specifying specific conditions are carried out according to conventional methods and conditions, or selected according to the product specifications.

[0072] Example 1

[0073] The furnace body monitored in this embodiment is a gasification furnace that processes 1500 tons of coal per day. Figure 1 As shown, it includes a liquid slag layer 1, a refractory brick layer 2 and a metal wall 3 from the inside to the outside. The refractory brick layer 2 includes a fire-facing brick layer, a backing brick layer and an insulating brick layer from the inside to the outside. The detailed operating parameters of the gasifier are shown in Table 1.

[0074] Table 1

[0075]

[0076]

[0077] The coal quality data in the gasifier are shown in Table 2 below.

[0078] Table 2

[0079]

[0080] The physical properties of the slag in the refractory brick layer and the liquid slag layer of the gasifier are shown in Table 3 below.

[0081] Table 3

[0082]

[0083] The monitoring device in this embodiment includes a data acquisition module connected to the gasifier, and also includes a data processing module. The data acquisition module is connected to the data processing module and is used to collect and measure the operating data required by the data processing module during calculation and operation. The data acquisition module includes a temperature measuring component, a coal slurry flow measurement component, a coal quality composition acquisition component and an oxygen flow measurement component. The temperature measuring component is a thermocouple, which is used to measure the temperature of the outer wall surface of the metal wall and the ambient temperature and transmit them to the data processing module II; the coal slurry flow measurement component is located on the coal slurry conveying pipeline, and is used to measure the coal slurry flow in the coal slurry conveying pipeline and transmit it to the data processing module I, and can also obtain the quality of the coal entering the gasifier and transmit it to the data processing module II; the coal quality composition acquisition component is located on the coal slurry conveying pipeline, and is used to measure the C element content, H element content, O element content, N element content, S element content, ash content and ash composition in the coal slurry conveying pipeline, and transmit the data to the data processing module I, and at the same time transmit the ash content to the data processing module II. The calculation process principle diagram of the monitoring device is as follows Figure 2 shown.

[0084] The data processing module includes a data processing module I, a data processing module II and a data processing module III. The data processing module I and the data processing module II are used to calculate the temperature T1 and T2 of the liquid slag layer, the flow speed u1 and u2 of the liquid slag layer, and the thickness δ1 and δ2 of the liquid slag layer respectively; the data processing module III is used to substitute the parameters calculated by the data processing modules I and II into (The value of C is 3.55*10 -3 ) formula, two sets of real-time online refractory brick erosion rates can be obtained; at the same time, two sets of temperature distribution data can also be obtained. The erosion rates of the refractory brick layers measured in real time online are cross-checked and averaged to determine the final erosion rate of the refractory brick layer, such as Figure 4 Shown is a graph of the erosion rate of the refractory brick layer measured in this example. Figure 4The solid line a represents the real-time online data measured in this embodiment 1, and point b is the data directly measured by experiment. As can be seen from the figure, the method of this embodiment realizes the real-time online accurate measurement of the corrosion rate of the refractory brick layer. By integrating the corrosion rate and time at each moment, the corrosion thickness Mt=M-∑J*t can also be obtained.

[0085] Data processing module I is: using numerical simulation method to carry out large-scale numerical simulation of the gasifier.

[0086] The calculation conditions include: gasifier pressure 1.0-7.0MPa, every 0.5MPa case; oxygen-coal ratio 400-550, coal 10 case; coal slurry concentration 45%-70%, coal 2% one case. Coal quality data covers: C\H\O\N\S\Ash\ every ±0.01 change. Coal slurry atomization particle size refers to coal The particle diameter of the slurry after being atomized by the nozzle can be obtained by experimental measurement or by calculation based on the oxygen content, coal slurry flow rate, operating pressure, and nozzle structure. The simulated operating data parameters of the gasifier are shown in Table 4 below.

[0087] Table 4

[0088]

[0089]

[0090] Combined with the data in Table 4, the computational fluid dynamics algorithm was used to establish a multiphase turbulent reaction flow database and 10 input variables (furnace space position, carbon content, hydrogen content, nitrogen content, sulfur content, ash content, coal slurry concentration, particle diameter, oxygen flow rate, and operating pressure) established by the DCS system. The neural network algorithm interpolation calculation model was used for calculation, and the real-time temperature of the liquid slag layer, the flow velocity of the liquid slag layer, the viscosity of the liquid slag layer, and the thickness of the liquid slag layer were obtained within 0.1 s.

[0091] The process of the neural network algorithm interpolation calculation model is as follows Figure 3 As shown. The learning rule of BP neural network uses the steepest descent method, and its topological structure generally contains three layers, namely the input layer, hidden layer and output layer. The basis of neural network algorithm includes two parts: forward propagation of signal and back propagation of error, that is, the calculation of actual output is carried out from input to output, while the correction of weights and thresholds is carried out from output to input.

[0092] Neural network learning is performed according to the data parameters in Table 4, and a mapping relationship is established between 10 input variables and the data parameters in the multiphase turbulent reaction flow database (gas temperature distribution near the inner wall of the furnace, gas velocity and gas concentration in the furnace, liquid slag deposition distribution on the inner wall of the fire face brick layer, and flow data of slag in the slag layer), and the mapping relationship is saved as the basic mapping model of the gasifier.

[0093] A neural network model with 10 parameters input and multiple outputs was established. Ten parameters including furnace space position, C content, H content, N content, S content, ash composition and content, coal slurry concentration, particle diameter, oxygen flow rate and operating pressure were taken as inputs of the BP neural network. According to the above basic mapping model, the temperature, flow velocity and thickness T1, u1 and δ1 of the liquid slag layer of the furnace to be monitored were calculated.

[0094] The calculation rules of the data processing module II are as follows: establish the heat conservation equation between the metal wall, the refractory brick layer and the liquid slag layer, substitute it into the formula of the heat flux density passing through the metal wall, the refractory brick layer and the liquid slag layer, and calculate the temperature of the liquid slag layer. At the same time, establish the mass conservation and momentum equations in the flow and heat transfer process of the liquid slag layer to calculate the thickness and flow velocity of the liquid slag layer.

[0095] The heat flux through the metal wall is calculated as:

[0096] q out,i =2πΔzr0(T m,i -T air )h air,i , T m,i is the temperature of the outer surface of the metal wall, T air is the ambient temperature, h air,i is the convective heat transfer coefficient between the outer wall of the metal wall and the atmosphere, △z is the height of the brick layer facing the fire, and h air according to Calculate, h conv is the natural convection constant, and c is the constant of the metal wall.

[0097] Among them, the calculation formula for the heat flux density of each layer in the refractory brick layer is:

[0098] T g,i The gas temperature near the inner wall surface in the furnace of the furnace to be monitored;

[0099] The calculated r j Substitute into the following formula to calculate the thickness of each layer:

[0100] r0=r m ,r1=r0-δ m ,r2=r1-δ r,c,r3=r2-δ r,1 ,r4=r3-δ r,2 ,r5=r4-δ r,3 ,r6=r5-δ s,i ; r5 is the inner diameter of the fire-facing brick layer, r6 is the inner diameter of the liquid slag layer, r4 is the inner diameter of the backing brick layer, r3 is the inner diameter of the insulation brick layer, r2 is the inner diameter of the refractory wool layer, r1 is the inner diameter of the metal wall, and r0 is the radius of the gasifier. The radius of the gasifier refers to the distance from the outer wall surface of the metal wall to the central axis of the gasifier; the refractory wool layer is located between the metal wall layer and the insulation brick layer;

[0101] k m , k r,c , k r,1 ,k r,2 ,k r,3 ,k s,i They are the thermal conductivity of the metal wall, the thermal conductivity of the refractory wool layer, the thermal conductivity of the insulation brick layer, the thermal conductivity of the backing brick layer, the thermal conductivity of the fire-facing brick layer and the liquid slag layer, which are obtained by querying the physical property parameters. r,1 =k r,c , k r,0 =k m ; The calculation rules of the slag thermal conductivity calculation module are: k s =k s,i is the thermal conductivity of the liquid slag layer, k1 is the function of the ash content, k2 is the function of the ash content, and T is the temperature of the slag in the slag layer;

[0102] δ m , δ r,c , δ r,1 ,δ r,2 ,δ r,3 , and δ s,i They are respectively the thickness of the metal wall, the thickness of the refractory wool layer, the thickness of the insulating brick layer, the thickness of the backing brick layer, the thickness of the fire-facing brick layer and the thickness of the liquid slag layer. The thicknesses of the metal wall, refractory wool layer, insulating brick layer and backing brick layer are constant values.

[0103] The calculation formula of the energy conservation equation is:

[0104] q out,i ×A m =q refc ×A rc =q ref1 ×A r1 =q ref2 ×A r2 =q ref3 ×A r3 =q refs ×A s,q out,i ,q refc ,q ref1 ,q ref2 ,q ref3 ,q refs A refers to the heat flux density passing through the metal wall, refractory wool layer, insulation brick layer, backing brick layer, fire facing brick and liquid slag layer respectively; m , A rc , A r1 , A r2 , A r3 , A s They refer to the radial heat transfer area of ​​the metal wall, the radial heat transfer area of ​​the refractory wool layer, the radial heat transfer area of ​​the insulation brick layer, the radial heat transfer area of ​​the backing brick layer, the radial heat transfer area of ​​the fire surface brick layer and the radial heat transfer area of ​​the liquid slag layer, that is, the temperature of the liquid slag layer;

[0105] The mass conservation equation in the process of liquid slag layer flow and heat transfer is: δ s,i It refers to the thickness of the liquid slag layer, in m; ρ s is the density of the slag in the liquid slag layer; m in,j is the amount of slag deposited on the inner wall of the gasifier, in kg, and its value is m in,j = coal quantity × ash content × 70%; L i is the equivalent circumference of the straight section of the cylinder in the gasifier, in m; x is the displacement of the particle in the liquid slag layer; i is the coordinate identifier of the position of the point, j is the coordinate range from the top of the gasifier to the i-th point, and the physical meaning is that the amount of slag at the i-th point is the sum of all deposited particles from the top to the i-th point;

[0106] The momentum equation is: The boundary conditions are v i (x) is the velocity distribution function in the liquid slag layer, η s is the viscosity of the liquid slag layer, v is the flow velocity of the liquid slag layer, g is the gravitational acceleration, β is the inclination angle of the inner wall of the slag gasifier, ρ s It refers to the density of the slag in the liquid slag layer, τ is the shear force on the inner wall of the gasifier; τ = 0.0303ρ g u0 2 ρ g It refers to the density of the synthesis gas in the gasifier, u0 2 It refers to the surface velocity of the liquid slag layer; r g Calculated according to the gasifier type, temperature and pressure; η s It is the basic physical property data of slag, obtained through analysis and testing, and its calculation rule is η s =ae bT, a and b are functions of coal ash content, and T is the temperature in the liquid slag layer.

[0107] The temperature of the outer wall surface of the metal wall is measured by the following measuring device: an infrared thermal imager assembly is arranged on the outer surface of the gasifier. The gasifier includes a dome and a straight section of the cylinder. The height h of the straight section of the cylinder is 9m, the outer diameter D of the straight section of the cylinder is 3.4m, and the gasification temperature is 1300°C. The infrared thermal imager assembly includes a first infrared thermal imager group distributed above the dome, and a second infrared thermal imager group distributed circumferentially on the straight section of the cylinder in the horizontal direction; the first infrared thermal imager group is an infrared thermal imager arranged directly above the dome; the second infrared thermal imager group is arranged in 3 layers in parallel (the 3 layers are based on the formula After calculation, rounded off), each layer has 3 (based on After calculation, the result is rounded off) infrared thermal imagers, a total of 10 infrared thermal imagers. The layers are evenly spaced, and each infrared thermal imager in each layer is evenly spaced. The viewing angle of the infrared thermal imager is a=50°. In the second infrared thermal imager group, the distance between the infrared thermal imager and the outer surface of the furnace to be measured is L (L=D), where L is the vertical distance between the infrared thermal imager and the central axis of the furnace to be measured minus the radius of the furnace to be measured. The infrared thermal imager uses a 382*288 pixel camera to obtain a 120mm 2 The temperature distribution at high resolution can achieve accurate temperature measurement.

Claims

1. A device for monitoring the corrosion rate of a refractory brick layer, characterized in that: It includes a data processing module and a data acquisition module connected to the furnace body to be monitored; The furnace body to be monitored includes a liquid slag layer, a refractory brick layer and a metal wall from the inside to the outside, and the refractory brick layer includes a fire-facing brick layer, a backing brick layer and an insulating brick layer from the inside to the outside; The data acquisition module is used to collect and measure the working condition data of the furnace body to be monitored required by the data processing module during calculation and operation. The data acquisition module is electrically connected to the data processing module and is used to transmit the obtained working condition data to the data processing module. The data processing module includes a data processing module I, a data processing module II and a data processing module III; the data processing module I and the data processing module II are respectively used to calculate the temperature T1 and T2 of the liquid slag layer, the flow speed u1 and u2 of the liquid slag layer, and the thickness δ1 and δ2 of the liquid slag layer; the data processing module III is a module for calculating the erosion rate of the liquid slag layer, and its calculation formula is shown as follows: C is the model constant of the liquid slag layer, η s is the viscosity of the liquid slag layer; Substituting the data parameters obtained by the data processing module I and the data processing module II into the calculation formula of the data processing module III, respectively obtaining the erosion rates J1 and J2 of the liquid slag layer; taking the average value of J1 and J2, which is the erosion rate of the refractory brick layer; The data processing module I is used to establish a multiphase turbulent reaction flow database and "the operating condition data of the furnace to be monitored acquired and measured by the data acquisition module" according to the computational fluid dynamics method, and calculate the T1, u1 and δ1 using an interpolation algorithm; The multiphase turbulent reaction flow database includes the gas temperature distribution near the inner wall surface in the furnace of the furnace body to be monitored, the gas flow speed in the furnace body to be monitored, the gas concentration in the furnace body to be monitored, the liquid slag deposition distribution on the inner wall surface of the fire face brick layer and the flow data parameters of the slag in the slag layer; the multiphase turbulent reaction flow database is established by using the computational fluid dynamics method according to the working condition data transmitted by the acquisition module; The data processing module I is electrically connected to the data processing module III, and is used to transmit the calculated data parameters to the data processing module III; The interpolation algorithm includes the following process: establishing a multiphase turbulent reaction flow database and the operating condition data transmitted from the data acquisition module to the data processing module I according to the computational fluid dynamics method, establishing a mapping relationship between the two, and obtaining a basic mapping model; then using the operating condition data transmitted from the data acquisition module to the data processing module I as the input of the interpolation algorithm and combining it with the basic mapping model to calculate T1, u1 and δ1; The data processing module II is used to establish the energy conservation equation between the metal wall, the refractory brick layer and the liquid slag layer, and then substitute the heat flux density formula that passes through the metal wall, the refractory brick layer and the liquid slag layer in sequence to calculate T2. It is also used to establish the mass conservation equation and momentum equation in the flow heat transfer process of the liquid slag layer, and jointly solve and calculate δ2 and u2; the data processing module II is electrically connected to the data processing module III, and is used to transmit the calculated data parameters to the data processing module III; In the data processing module II, the energy conservation equation is: q out，i ×A m =q ref,1 ×A r1 =q ref,2 ×A r2 =q ref,3 ×A r3 =q ref,s ×A s ,q out,i ,q ref,1 ,q ref,2 ,q ref,3 ,q ref,s are the heat flux densities passing through the metal wall, the insulating brick layer, the backing brick layer, the fire-facing bricks and the liquid slag layer, respectively. m , A r1 , A r2 , A r3 , A s They refer to the radial heat transfer areas of the metal wall, the insulating brick layer, the backing brick layer, the fire-facing brick layer and the liquid slag layer, respectively, and the temperature of the liquid slag layer is obtained; The heat flux density passing through the metal wall is calculated as: out,i =2πΔzr0(T m,i -T air )h air,i , T m,i is the temperature of the outer wall of the metal wall, T air is the ambient temperature, h air,i is the convection heat transfer coefficient between the outer wall of the metal wall and the atmosphere, △z is the height of the fire-facing brick layer; h air,i according to Calculated; The calculation formula of the heat flux density passing through each layer of the refractory brick layer is: In the formula, q ref,i =q out,i , T g,i is the gas temperature near the inner wall surface in the furnace of the furnace body to be monitored, r is the inner diameter of each corresponding layer, k is the thermal conductivity of each corresponding layer, and the thickness of the liquid slag layer is calculated; 70wt.% of the coal added to the furnace to be monitored is produced after gasification reaction and is deposited on the inner wall of the fire-facing brick layer to form the liquid slag layer, and is evenly distributed. The slag flow in the liquid slag layer satisfies the Newtonian fluid flow. The mass conservation equation established for the flow heat transfer process of the liquid slag layer is: δ s,i It refers to the thickness of the liquid slag layer, in m; ρ s is the density of the liquid slag layer; m in,j is the amount of slag deposited on the inner wall of the furnace to be monitored, in kg, and its value is m in,j = mass of carbon-containing material entering the furnace × ash content × 70%; L i is the equivalent circumference of the straight section of the cylinder in the furnace to be monitored, in meters; The momentum equation is The boundary conditions are g is the acceleration of gravity, β is the inclination angle of the slag flowing on the inner wall surface of the furnace body to be monitored, and τ is the shear force on the inner wall surface of the furnace body to be monitored.

2. The erosion rate monitoring device for refractory brick layer according to claim 1, characterized in that: The furnace body to be monitored is a gasification furnace; And / or, the viscosity of the liquid slag layer is the basic data of the physical properties of the furnace to be monitored And / or, the model constant of the liquid slag layer has a value range of (0.1 to 100)*10 -3 .

3. The erosion rate monitoring device for refractory brick layer according to claim 2, characterized in that: The viscosity of the liquid slag layer is obtained based on the prediction of the ash composition of the coal entering the furnace to be monitored; And / or, the model constant of the liquid slag layer has a value range of (1 to 10)*10 -3 .

4. The erosion rate monitoring device for a refractory brick layer according to claim 3, characterized in that: The model constant of the liquid slag layer is 3.55*10 -3 .

5. The erosion rate monitoring device for a refractory brick layer according to claim 1, characterized in that: The data acquisition module includes a coal slurry flow measurement component, a coal quality composition acquisition component, an oxygen flow measurement component and a temperature measurement component.

6. The erosion rate monitoring device for a refractory brick layer according to claim 5, characterized in that: The coal slurry flow measurement component is used to measure the coal slurry flow in the coal slurry conveying pipeline, and the coal slurry flow measurement component is electrically connected to the data processing module I, and is used to transmit the measured coal slurry flow to the data processing module I; the coal slurry conveying pipeline is used to convey the gasified coal into the furnace body to be monitored; And / or, the coal slurry flow measurement component is further used to obtain the amount of coal entering the furnace body to be monitored, and the coal slurry flow measurement component is electrically connected to the data processing module II, and is used to transmit the obtained data of the amount of coal entering the furnace body to be monitored to the data processing module II; And / or, the coal quality composition acquisition component is used to measure the C content, H content, O content, N content, S content, ash content and ash composition in the coal in the coal slurry conveying pipeline, and the coal quality composition acquisition component is electrically connected to the data processing module I, and is used to transmit the measured data parameters to the data processing module I; the coal quality composition acquisition module is also electrically connected to the data processing module II, and is used to transmit the measured ash content data to the data processing module II; And / or, the oxygen flow measurement component is used to measure the oxygen flow delivered to the furnace body to be monitored, and the oxygen flow measurement component is electrically connected to the data processing module I, and is used to transmit the measured oxygen flow data to the data processing module I; And / or, the temperature measuring component is used to measure the temperature of the outer wall surface of the metal wall and the ambient temperature close to the outer wall surface of the metal wall, and the temperature measuring component is electrically connected to the data processing module II for transmitting the measured data to the data processing module II.

7. The erosion rate monitoring device for a refractory brick layer according to claim 1, characterized in that: The interpolation algorithm includes a neural network algorithm or a kriging interpolation method.

8. The erosion rate monitoring device for a refractory brick layer according to claim 7, characterized in that: The interpolation algorithm is a neural network algorithm.

9. The erosion rate monitoring device for a refractory brick layer according to claim 1, characterized in that: The data processing module also includes a liquid slag layer erosion accumulation initialization and integrator, which is used for the cumulative calculation of the erosion thickness of the refractory brick layer and the calculation of the remaining thickness of the refractory brick layer.

10. The erosion rate monitoring device for a refractory brick layer according to claim 1, characterized in that: The data processing module further comprises a verification module, which is electrically connected to the data processing module III and is used to obtain an average value of J1 and J2.

11. A method for monitoring the corrosion rate of a refractory brick layer, characterized in that: The device for monitoring the corrosion rate of the refractory brick layer according to any one of claims 1 to 10 is used, and comprises the following steps: (1) using the data acquisition module to collect data; (2) The data collected in step (1) is transmitted to the data processing module for calculation and processing.

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