High-temperature ash adhesion strength testing device and method for evaluating boiler ash deposition

Abstract

According to the high-temperature ash adhesion strength testing device and method for evaluating boiler ash deposition, boiler ash in the boiler combustion process is simulated through the ash separation sheet, the heating surface of the boiler is simulated through the two metal columns, the boiler is heated to the high temperature through the electric heating furnace, and the boiler ash deposition is evaluated. The two metal columns are used for pressing the ash slices and then pulling back the ash slices, and the pulling force during pulling back is used for representing the adhesion strength of the boiler ash on the heating surface, so that the adhesion condition of the boiler ash in the actual boiler combustion process can be well simulated, and test data which are very close to the adhesion strength of the actual boiler ash can be measured. According to the device and the method, the defect that the interaction between the deposited ash and the heating surface cannot be directly and quantitatively tested by the existing device and method is overcome, an ash deposition tendency evaluation system is perfected, and a new thought is provided for judging the ash deposition tendency and exploring the ash deposition mechanism.

Description

Technical Field

[0001] The invention relates to an adhesion property testing device and method, and in particular to a high-temperature ash adhesion strength testing device for evaluating boiler ash deposition tendency and a corresponding testing method. Background Art

[0002] Against the backdrop of global energy uncertainty, solid fuels such as coal remain the most reliable and mature type of energy. At the same time, in the process of energy transformation, solid fuels such as biomass and solid waste play an important role in reducing carbon emissions from fossil fuels. However, whether it is biomass, solid waste or coal, these solid fuels contain inorganic minerals, which will partially melt during the combustion process to form ash and slag and deposit on various heating surfaces inside the boiler, leading to ash deposition problems. This will lead to a decrease in boiler heat transfer efficiency, increase carbon emissions, and corrode equipment. Therefore, regular and irregular shutdown maintenance is required to avoid operational risks, resulting in downtime and cost consumption. In the context of "dual carbon", boiler combustion further requires improving boiler efficiency and reducing carbon emissions to achieve stable energy supply during the transition period. Therefore, it is crucial to predict and evaluate the tendency of boiler ash deposition, explore the ash deposition mechanism of different fuels, and alleviate the ash deposition phenomenon.

[0003] At present, the research methods on ash deposition characteristics mainly evaluate the ash deposition trend through the ash particle characteristics such as ash content, ash composition and ash melting characteristics. However, the final deposition of ash particles on the heated surface is affected by many factors such as ash particle capture rate, collision rate and adhesion rate.

[0004] Specifically, ash formation rate, ash cost and ash melting characteristics can provide some information about the ash deposition tendency, but they cannot independently and accurately determine the ash deposition tendency. Among them, the ash formation rate can indicate the content of inorganic minerals, but it cannot explain the chemical and physical properties of the ash; fuels with high ash formation rates may not have serious ash deposition due to their high melting point and low adhesion. Ash composition can provide information on the types of minerals in the fuel, but different minerals will show different ash deposition characteristics under different combustion conditions. Ash melting characteristics are more widely used than the first two methods and can provide the melting behavior of minerals at high temperatures, but they cannot accurately predict the adhesion rate with the heat exchange surface in the boiler during combustion. Therefore, they are not sufficient to accurately determine the ash deposition during combustion.

[0005] The collision speed and collision angle of ash particles are mainly affected by physical conditions such as boiler structure, operating conditions, and ash particle size. Under the same physical conditions, the adhesion strength between the ash particles themselves and the heating surface becomes the key factor affecting the adhesion rate. When the ash adhesion strength increases, the ash particles are more likely to adhere to the heating surface, thereby preventing the ash particles from escaping, enhancing the ability to capture ash particles in the flue gas, improving the capture efficiency, and aggravating ash deposition. Higher ash adhesion strength also means that more ash particles can adhere to the surface of the heating surface, and it is not easy to fall off under the gravity of the ash particles themselves and the scouring of flue gas. This leads to an increase in the ash thickness on the boiler heating surface and increases the difficulty of the boiler soot blowing process. However, current research cannot quantitatively analyze the interaction between ash and the heating surface, and the adhesion strength of ash particles to the surface of the heating surface is an important parameter for the ash deposition tendency of the reaction fuel.

[0006] Therefore, there is a need for a method that can quantitatively analyze the adhesion strength between the deposited ash and the heated surface to improve the evaluation of the ash deposition characteristics of different types of fuels.

[0007] In the prior art, although there are some test devices and test methods for adhesion characteristics, such as the test devices and corresponding test methods disclosed in CN117782973A, CN117054331A, and CN117800559A, these test devices and test methods are all test devices and test methods under a given scenario, and cannot restore the adhesion effect between ash and the heating surface during boiler combustion. In particular, since the changes in the morphology of ash and the mineral occurrence morphology in the ash during boiler combustion involve chemical processes such as mineral transformation, and the temperature range of the above test methods is relatively low, the physical and chemical properties of metal and ash particles in the cold and hot processes are very different, so it is impossible to quantitatively analyze the adhesion characteristics of ash in the boiler through the above test devices and test methods. Summary of the invention

[0008] The present invention is made to solve the above problems, and aims to provide a high temperature ash adhesion strength test device and a corresponding test method capable of quantitatively analyzing the adhesion characteristics of ash in a boiler. The present invention adopts the following technical solutions:

[0009] The present invention provides a high-temperature ash adhesion strength testing device for evaluating the deposition tendency of boiler ash, which is used to test the adhesion strength of ash sheets, and the ash sheets are used to simulate the ash in the boiler. The device has the following technical features, which include: an electric heating furnace; a bearing column, which is arranged in the furnace of the electric heating furnace and is used to bear the ash sheets; a pressure column, which is arranged in the furnace and is located directly above the bearing column; a traction motor, which is connected to the pressure column and is used to drive the pressure column to rise and fall, so as to apply pressure to the ash sheet or pull it back after applying pressure; and a tension sensor, which is connected between the pressure column and the traction motor and is used to collect tension data corresponding to the adhesion strength during the process of pulling back after applying pressure, wherein the bearing column and the pressure column are both metal columns, which are used to simulate the heating surface of the boiler, and the electric heating furnace can heat its furnace to above 1500°C.

[0010] The high-temperature ash adhesion strength testing device for evaluating the boiler ash deposition tendency provided by the present invention may also have such technical features, wherein the bearing column and the pressure column are both made of high-chromium-nickel austenitic stainless steel 310S and are cylindrical, the upper end surface of the bearing column and the lower end surface of the pressure column are flat, the bearing column and the pressure column are both vertically arranged, the upper end surface of the bearing column is used to place the ash sheet, and the lower end surface of the pressure column faces the upper end surface of the bearing column.

[0011] The present invention provides a high-temperature ash adhesion strength testing device for evaluating the deposition tendency of boiler ash. The electric heating furnace is a temperature-controlled box-type muffle furnace with a temperature controller. A temperature meter is arranged in the furnace of the electric heating furnace. The temperature controller controls the heating of the electric heating furnace according to the temperature measured by the temperature meter and a predetermined target temperature.

[0012] The high-temperature ash adhesion strength testing device provided by the present invention is used to evaluate the deposition tendency of boiler ash. The maximum measuring range of the tension sensor is ±5kg and the accuracy is 0.1g.

[0013] The present invention provides a test method for testing the adhesion strength of an ash sheet using the above-mentioned high-temperature ash adhesion strength test device for evaluating the deposition tendency of boiler ash. The ash sheet is used to simulate the ash in the boiler. The method has the following technical features, which include the following steps: a heating step, placing the ash sheet on the upper end surface of the supporting column, starting the electric heating furnace, raising the temperature in the furnace to a predetermined target temperature, and maintaining the target temperature for a predetermined time to make the temperature in the furnace uniform; a constant temperature pressurizing step, while keeping the temperature in the furnace stable, starting the traction motor and stopping the traction motor after a predetermined time, so that the traction motor drives the pressure column to descend and applies a predetermined pressure to the ash sheet on the supporting column; a pull-back test step, starting the traction motor, so that the traction motor drives the pressure column to rise at a predetermined speed, pressurizes the ash sheet and then pulls it back, and the tension sensor collects tension data corresponding to the adhesion strength during the process of pulling back after pressurization; and an ash adhesion strength calculation step, calculating the adhesion strength of the boiler ash based on the tension data.

[0014] The test method provided by the present invention may also have such technical features, wherein the target temperature is within the temperature range of 20°C to 1500°C, in the heating step, the temperature in the furnace is maintained for more than 20 minutes after rising to the target temperature, in the constant temperature pressurizing step, the predetermined pressure is 5N, and in the pull-back test step, the predetermined speed is 0.5mm / s.

[0015] The testing method provided by the present invention may also have such a technical feature, wherein, multiple temperatures are selected within the temperature range of 20°C to 1500°C as multiple target temperatures, and the above-mentioned heating step to the ash adhesion strength calculation step is repeated for each target temperature; a plurality of groups of the bearing columns and the pressure columns made of different metal materials are prepared, and the above-mentioned heating step to the ash adhesion strength calculation step is repeated for each group of the bearing columns and the pressure columns.

[0016] The test method provided by the present invention may also have such a technical feature, wherein the ash sheet is in the shape of a circular sheet, the tension data is a tension peak value, the constant temperature pressurizing step and the pull-back test step are repeated multiple times to obtain multiple tension peak values, and in the ash adhesion strength calculation step, the average value of the multiple tension peak values ​​is calculated as the effective tension peak value, and the adhesion strength is calculated based on the effective tension peak value and the cross-sectional area of ​​the ash sheet:

[0017]

[0018] In the formula, F maxis the effective tensile peak value, and S is the cross-sectional area of ​​the ash sheet.

[0019] The testing method provided by the present invention may also have such technical features, that before the heating step, it also includes: an end face grinding step, grinding the upper end face of the bearing column and the lower end face of the pressure column to make them smooth; and a sensor calibration step, when heating to temperatures of 500°C, 1000°C and 1500°C in the furnace, respectively, connecting counterweights of 0.05kg, 0.5kg and 5kg to the tension sensor at each temperature and calibrating the tension data measured by it.

[0020] The test method provided by the present invention may also have such a technical feature, before the heating step, it also includes: an ash sheet preparation step, placing an ash sample powder corresponding to the boiler ash into a cylindrical mold, and uniaxially extruding the ash sample powder in the cylindrical mold for 300s at a pressure of 20Mpa to form the ash sheet, wherein a plurality of ash sheets of different materials are prepared in the ash sheet preparation step, and the above-mentioned heating step is repeated for each ash sheet until the ash adhesion strength calculation step.

[0021] Function and Effect of the Invention

[0022] According to the high-temperature ash adhesion strength test device and method for evaluating the boiler ash deposition tendency of the present invention, an ash slice is used to simulate the boiler ash in the boiler combustion process, two metal columns are used to simulate the boiler's heating surface, and it is heated to a high temperature by an electric heating furnace, and the two metal columns are used to pressurize the ash slice and then pull it back, and the tension during the pull-back is used to characterize the adhesion strength of the boiler ash on the heating surface. Therefore, it is possible to simulate the adhesion of the boiler ash in the actual boiler combustion process well, and measure test data that is very close to the actual boiler ash adhesion strength. The device and method of the present invention make up for the deficiency of the existing devices and methods that cannot directly quantify the interaction between the test deposited ash and the heating surface, improve the ash deposition tendency evaluation system, and provide a new idea for judging the ash deposition tendency and exploring the ash deposition mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic structural diagram of a high-temperature ash adhesion strength testing device for evaluating boiler ash deposition tendency in an embodiment of the present invention;

[0024] Figure 2 It is a structural schematic diagram of a part of the structure of a high-temperature ash adhesion strength testing device for evaluating boiler ash deposition tendency in an embodiment of the present invention;

[0025] Figure 3 yes Figure 2 An enlarged view of the portion within the middle frame A;

[0026] Figure 4 4 is a flow chart of a high temperature ash adhesion strength test method for evaluating boiler ash deposition tendency in an embodiment of the present invention.

[0027] Reference numerals:

[0028] High-temperature ash adhesion strength testing device 10; frame 11; heating furnace 12; furnace door 121; furnace chamber 122; temperature controller 123; through hole 124; temperature meter 13; bearing mechanism 15; bearing column 151; bearing column base 152; pressure-pullback testing mechanism 16; pressure column 161; connecting guide assembly 162; screw 1621; connecting rod 1622; tension sensor 163; traction motor 164. DETAILED DESCRIPTION

[0029] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the high-temperature ash adhesion strength testing device and testing method for evaluating the boiler ash deposition tendency of the present invention are specifically described below in combination with embodiments and drawings.

[0030] <Example>

[0031] This embodiment provides a high-temperature ash adhesion strength testing device and a testing method for evaluating the ash deposition tendency of a boiler, which are used to simulate the ash adhesion characteristics during the actual boiler combustion process.

[0032] In the actual boiler combustion process, if the adhesion strength between the ash and the heating surface is high, the ash particles are more likely to adhere to the heating surface and can adhere more tightly to the boiler surface. At this time, more ash particles can be deposited on the heating surface and are not easy to fall off, resulting in a thicker deposition layer, more serious ash deposition problems, and difficulties in the soot blowing process. On the contrary, lower ash adhesion strength makes it easier for the deposited ash to fall off under its own gravity and the action of flue gas, the ash accumulation thickness is thinner, and the risk of ash deposition is lower. Therefore, exploring the ash adhesion strength can predict the ash deposition problems of different fuels, working conditions and heating surface surfaces, which can provide new ideas for studying ash deposition characteristics and provide a basis for alleviating ash deposition in actual engineering applications.

[0033] The device and method of this embodiment will be described in detail below with reference to the accompanying drawings.

[0034] Figure 1 is a schematic diagram of the structure of a high-temperature ash adhesion strength testing device for evaluating the boiler ash deposition tendency in this embodiment, Figure 2 : is a schematic diagram of a part of the structure of a high temperature ash adhesion strength test device for evaluating the boiler ash deposition tendency in this embodiment, to show the internal structure, Figure 2 The furnace door and front panel of the heating furnace are omitted.

[0035] like Figure 1 and Figure 2 As shown, a high temperature ash adhesion strength testing device 10 (hereinafter referred to as testing device 10 ) for evaluating boiler ash deposition tendency includes a frame 11 , an electric heating furnace 12 , a temperature measuring device 13 , a temperature controller 14 , a supporting mechanism 15 and a pressure testing mechanism 16 .

[0036] The electric heating furnace 12 is arranged on the frame 11, and has a furnace chamber 122 inside. The front panel of the electric heating furnace 12 has a furnace door 121, and the electric heating furnace 12 has a temperature controller 123. In addition, a through hole 124 is provided on the top plate of the electric heating furnace 12. In this embodiment, the electric heating furnace 12 is a temperature-controlled box-type muffle furnace, which can heat the furnace chamber 122 to above 1500°C.

[0037] The temperature detector 13 is a thermocouple, which is arranged in the furnace 122 and is used to measure the real-time temperature in the furnace 122. The temperature controller 123 controls the heating power of the heating furnace 12 according to the set target temperature and the real-time temperature in the furnace 122 measured by the temperature detector 13, so that the temperature in the furnace 122 can reach the target temperature.

[0038] The bearing mechanism 15 is used to bear the ash sample to be tested, and includes a bearing column 151 and a bearing column base 152. The bearing column base 152 is a metal part with a mounting groove, which is fixed on the inner bottom surface of the furnace 122; the bearing column 151 is a cylindrical metal column, whose diameter corresponds to the ash sample to be tested, and whose length is less than the height of the furnace 122. The bearing column 151 is vertically arranged, one end of which is embedded and fixed in the mounting groove on the bearing column base 152, and the other end is located in the middle of the furnace 122, and its upper end surface is roughly horizontal. In this embodiment, the bearing column 151 is made of high chromium-nickel austenitic stainless steel 310S (0Cr25Ni20), which has good oxidation resistance and high temperature deformation resistance.

[0039] The pressure-pullback test mechanism 16 is used to test the ash sample carried by the carrying mechanism 15 by applying pressure and then pulling it back, and includes a pressure column 161 , a connecting guide assembly 162 , a tension sensor 163 and a traction motor 164 .

[0040] The pressure column 161 is a cylindrical metal column, which is used to cooperate with the bearing column 151 to apply pressure to the ash sample placed on the bearing column 151. The pressure column 161 is also vertically arranged in the furnace 122 and coaxially arranged with the bearing column 151, and its lower end surface is approximately horizontal and faces the upper end surface of the bearing column 151. In this embodiment, the diameter of the pressure column 161 is substantially the same as that of the bearing column 151, and is also made of high chromium-nickel austenitic stainless steel 310S.

[0041] The connecting guide assembly 162 is used to connect one end of the pressure column 161 to the traction motor 164, so that the pressure column 161 can move in the vertical direction under the drive of the traction motor 164, and guide the pressure column 161 during its movement. The connecting guide assembly 162 can adopt a corresponding structure in the prior art, for example, two guide rods, a lead screw 1621 and a connecting rod 1622 can be adopted, one end of the lead screw 1621 is connected to the output shaft of the traction motor 164, and the other end is connected to one end of the connecting rod 1622, and the other end of the connecting rod 1622 is connected to the upper end of the pressure column 161, so that the connecting rod 1622 and the pressure column 161 can be driven to move up and down by the lead screw 1621, and their movement is guided by the two guide rods. The connecting rod 1622 passes through the through hole 124 on the electric heating furnace 12 and can move in the through hole 124. The diameter of the connecting rod 1622 can be set to be smaller than the diameter of the pressure column 161, and a certain heat insulation structure can be set between the connecting rod 1622 and the inner wall of the through hole 124.

[0042] The tension sensor 163 is disposed between the pressure column 161 and the traction motor 164 through the connecting guide assembly 162, and is used to measure the tension between the traction motor 164 and the pressure column 161 when the traction motor 164 pulls the pressure column 161 upward. In this embodiment, the maximum range of the tension sensor 163 is ±5kg, and the accuracy is 0.1g. When the connecting guide assembly 162 adopts the above structure, the tension sensor 163 can be connected between the lead screw and the connecting rod.

[0043] The test device 10 also includes a controller (not shown in the figure) for allowing the user to set the target temperature and start the test. After the user starts the test through the controller, the controller controls the electric heating furnace 12 and the traction motor 164 according to the set target temperature and predetermined control parameters.

[0044] Figure 3 yes Figure 2 An enlarged view of the portion within frame A.

[0045] like Figure 3 As shown, in this embodiment, the ash sample to be tested is an ash sheet 20 in a flat cylindrical shape (or round sheet shape) formed by extrusion, and the diameter of the bearing column 151 and the diameter of the pressure column 161 are both larger than the diameter of the ash sheet 20. During the test, the ash sheet 20 is roughly placed at the center of the upper end surface of the bearing column 151, and the ash sheet 20 will not fall off or partially fall off. After extrusion, the ash sheet 20 will not fall off or partially fall off even if its diameter becomes larger.

[0046] Figure 4 4 is a flow chart of a high temperature ash adhesion strength test method for evaluating boiler ash deposition tendency in this embodiment.

[0047] like Figure 4As shown, the test method specifically includes the following steps:

[0048] Step S1, ash flake preparation step, puts the ash sample powder after standard ash making into a cylindrical mold and extrude it to form ash flakes.

[0049] In this embodiment, the ash-like powder after standard ash making is placed in a cylindrical mold with a diameter of 12.7 mm, and the area S of its axial section is calculated. Then, the ash-like powder in the mold is uniaxially extruded for 300 seconds at a pressure of 20 MPa to form the above-mentioned ash sheet 20.

[0050] Step S2, the end face polishing step, before starting the test, the upper end face of the supporting column 151 and the lower end face of the pressure column 161 (that is, the surface where the two metal columns contact the ash sheet) are polished to ensure that these surfaces are smooth and avoid their surface roughness from interfering with the test results.

[0051] In this embodiment, 300-grit sandpaper is used to grind the upper end surface of the bearing column 151 and the lower end surface of the pressure column 161 .

[0052] It can be understood that step S1 and step S2 can be performed separately and simultaneously.

[0053] Step S3, a sensor calibration step, calibrates the tension sensor 163 under heating conditions to ensure that the ash adhesion strength can be accurately measured at the target temperature.

[0054] In this embodiment, when the furnace 122 is heated to 500°C, 1000°C and 1500°C respectively, weights of 0.05kg, 0.5kg and 5kg are added at each temperature respectively (i.e., one end of the tension sensor 163 is fixed and the other end is connected to a counterweight of corresponding weight) and the tension measured by the tension sensor 163 is calibrated to confirm the linear relationship between the tension and weight.

[0055] Step S4, a heating step, places the ash slice 20 at the center of the upper end surface of the supporting column 151, starts the electric heating furnace 12, raises the temperature in the furnace 122 to the target temperature and maintains it at the target temperature for a predetermined time to make the temperature in the furnace 122 uniform.

[0056] In this embodiment, the electric heating furnace 12 is heated to the target temperature at a heating rate of 10°C / min and maintained at the target temperature for 20 minutes to ensure a uniform temperature in the furnace 122. The target temperature is a temperature selected from a temperature range of room temperature to 1500°C.

[0057] Step S5, a constant temperature pressure step, starts the traction motor 164 and stops the motor after a predetermined time while keeping the temperature in the furnace 122 stable (i.e., the temperature is basically maintained at the target temperature), so that the traction motor 164 drives the pressure column 161 to slowly descend toward the supporting column 151 and applies a predetermined pressure to the ash sheet 20 on the supporting column 151.

[0058] In this embodiment, the height of the upper pressure column 161 is controlled to ensure that a constant pressure of 5N is applied to the ash slices 20, and the pressure and the temperature in the furnace 122 are maintained for 1 hour.

[0059] Step S6, a pull-back test step, starts the traction motor 164 so that the traction motor 164 drives the pressure column 161 to slowly rise at a predetermined speed, and at the same time, the tension sensor 163 collects the tension change of the pressure column 161 during the pull-back process.

[0060] In this embodiment, the traction motor 164 drives the pressure column 161 to slowly rise at a speed of 0.5 mm / s, and at the same time, the tension sensor 163 collects the peak value of the tension during the pulling back process of the pressure column 161.

[0061] Step S7, the step of calculating the ash adhesion strength, calculates the adhesion strength of the ash sample based on the area calculated in step S1 and the tension change collected in step S6.

[0062] In this embodiment, for each ash sheet 20, the above steps S5 to S6 are repeated three times, and the three tensile peak values ​​are measured and the average value is taken as the effective tensile peak value F max .

[0063] Based on the area S and effective tensile force peak F calculated in step S1 max , calculate the adhesion strength P of ash according to the following formula:

[0064]

[0065] In this embodiment, multiple temperature values ​​are selected as target temperatures within the temperature range of room temperature (e.g., 20°C) to 1500°C. For each target temperature, other conditions (including pressure, tableting time, mold model, heating rate, etc.) are kept unchanged and the above steps S2 to S7 are repeated to realize control variables and simulate the influence of different temperatures on ash adhesion strength during actual boiler combustion. In an alternative scheme, the target temperature can also be selected only in the high temperature section, for example, within the temperature range of 500°C to 1500°C, or within the temperature range of 1000°C to 1500°C.

[0066] Similarly, ash slices of various materials may be prepared in step S1. For each ash slice, other conditions are kept unchanged and steps S2 to S7 are repeated to simulate the effect of different fuels on ash adhesion strength during actual boiler combustion.

[0067] Similarly, multiple groups of supporting columns 151 and pressure columns 161 (metal columns) made of different metal materials can be prepared. For each group of metal columns, other conditions are kept unchanged and the above steps S2 to S7 are repeated to simulate and study the influence of different heating surface materials on ash adhesion strength during actual boiler combustion.

[0068] In addition, in order to verify the repeatability of the test, each set of conditions was tested three times, that is, the above steps were repeated three times. For the same set of conditions, the errors of multiple test results were controlled within 5%, verifying the stability and reliability of the above test device 10 under different temperature and load conditions.

[0069] The above-mentioned test device 10 and test method are helpful to systematically study and compare the changes in ash adhesion strength under different conditions, and provide a scientific basis for further understanding the ash deposition characteristics and optimizing the combustion process.

[0070] Functions and Effects of the Embodiments

[0071] According to the high-temperature ash adhesion strength test device and method for evaluating the boiler ash deposition tendency provided by this embodiment, the boiler ash in the boiler combustion process is simulated by an ash slice, the boiler heating surface is simulated by two metal columns, and it is heated to a high temperature by an electric heating furnace, and the ash slice is pressed and pulled back by two metal columns, and the adhesion strength of the boiler ash on the heating surface is characterized by the pulling force during the pullback, so that the adhesion of the boiler ash in the actual boiler combustion process can be well simulated, and the test data of the adhesion strength of the actual boiler ash can be measured. The device and method of this embodiment make up for the deficiency of the existing device and method that cannot directly quantify the interaction between the test deposited ash and the heating surface, improve the ash deposition tendency evaluation system, and provide a new idea for judging the ash deposition tendency and exploring the ash deposition mechanism.

[0072] In the embodiment, the ash slices and the two metal columns can be heated to a maximum of 1500°C by an electric heating furnace, thereby better simulating the high temperature conditions in the actual boiler combustion process and is not limited to cold state research. This feature makes the device and method of this embodiment more applicable and accurate in studying the ash adhesion characteristics in the boiler combustion process.

[0073] In the embodiment, the bearing column and the pressure column are both made of high-chromium-nickel austenitic stainless steel 310S, which has good oxidation resistance and high-temperature deformation resistance, so that the device can measure accurate test data even under high temperature conditions.

[0074] In the embodiment, after repeating the test steps for multiple times to measure multiple tensile peak values, the average value is calculated as the effective tensile peak value, and then the ash adhesion strength is calculated based on the effective tensile peak value, which can reduce the test error and obtain a more accurate ash adhesion strength with more reference value.

[0075] Furthermore, by preparing multiple ash slices of different materials to simulate boiler ash with different compositions and characteristics, and repeating the test steps for each ash slice while keeping other conditions unchanged, it is possible to conveniently and effectively study the influence of different fuels on ash adhesion strength during actual boiler combustion.

[0076] Furthermore, by setting multiple target temperatures ranging from room temperature to 1500°C to simulate different temperatures in the boiler, and repeating the test steps for each target temperature while keeping other conditions unchanged, it is possible to conveniently and effectively study the influence of different temperatures on ash adhesion strength during actual boiler combustion.

[0077] Furthermore, by preparing multiple groups of metal columns of different materials to simulate heating surfaces of different materials, and repeating the test steps for each group of metal columns while keeping other conditions unchanged, it is possible to conveniently and effectively study the influence of different heating surface materials on ash adhesion strength during actual boiler combustion.

[0078] Furthermore, before the test began, the surfaces of the two metal columns in contact with the ash sheets were polished, and the tensile sensor was calibrated under heating conditions, thereby avoiding or reducing the interference of the rough contact surface on the adhesion characteristics test and ensuring that the tensile sensor outputs accurate signal data under heating conditions, thereby further improving the accuracy of the test.

[0079] The above embodiments are only used to illustrate the specific implementation of the present invention, and the present invention is not limited to the description scope of the above embodiments. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and descriptions are only to illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A high temperature ash adhesion strength test device for evaluating boiler ash deposition tendency, used for testing the adhesion strength of ash slices, the ash slices are used to simulate ash in a boiler, characterized in that: include: Electric heating furnace; A bearing column, arranged in the furnace of the electric heating furnace, for bearing the ash slices; A pressure column is arranged in the furnace and is located directly above the bearing column. A traction motor is connected to the pressure column and is used to drive the pressure column to move up and down, so as to apply pressure to the ash slice or pull it back after applying pressure; as well as A tension sensor is connected between the pressure column and the traction motor, and is used to collect tension data corresponding to the adhesion strength during the process of pulling back after the pressure is applied. The bearing column and the pressure column are both metal columns, which are used to simulate the heating surface of the boiler. The electric heating furnace can heat the furnace chamber to above 1500°C.

2. The high temperature ash adhesion strength testing device for evaluating boiler ash deposition tendency according to claim 1, characterized in that: in, The bearing column and the pressure column are both cylindrical, and the upper end surface of the bearing column and the lower end surface of the pressure column are flat. The bearing column and the pressure column are both arranged vertically, and the upper end surface of the bearing column is used to place the ash slices. The lower end surface of the pressure column faces the upper end surface of the bearing column.

3. The high temperature ash adhesion strength testing device for evaluating boiler ash deposition tendency according to claim 1, characterized in that: in, The electric heating furnace is a temperature-controlled box-type muffle furnace with a temperature controller. A temperature measuring device is arranged in the furnace of the electric heating furnace. The temperature controller controls the heating of the electric heating furnace according to the temperature measured by the temperature detector and a predetermined target temperature.

4. The high temperature ash adhesion strength testing device for evaluating boiler ash deposition tendency according to claim 1, characterized in that: in, The maximum measuring range of the tension sensor is ±5kg, and the accuracy is 0.1g.

5. A method for testing the adhesion strength of an ash sheet using a high temperature ash adhesion strength testing device for evaluating boiler ash deposition tendency as described in any one of claims 1 to 4, wherein the ash sheet is used to simulate ash in a boiler, characterized in that: The following steps are involved: a heating step, placing the ash slice on the upper end surface of the supporting column, starting the electric heating furnace, raising the temperature in the furnace to a predetermined target temperature, and maintaining the target temperature for a predetermined time to make the temperature in the furnace uniform; a constant temperature pressure applying step, in which the traction motor is started and stopped after a predetermined time while the temperature in the furnace is kept stable, so that the traction motor drives the pressure applying column to descend and applies a predetermined pressure to the ash slice on the supporting column; a pull-back test step, starting the traction motor so that the traction motor drives the pressure column to rise at a predetermined speed, pressurizes the ash sheet and then pulls it back, and the tension sensor collects tension data corresponding to the adhesion strength during the process of pulling back after pressurization; as well as The ash adhesion strength calculation step is to calculate the adhesion strength of the boiler ash based on the tension data.

6. The testing method according to claim 5, characterized in that: in, The target temperature is within the temperature range of 20°C to 1500°C. In the heating step, the temperature in the furnace is maintained for more than 20 minutes after rising to the target temperature. In the constant temperature pressurizing step, the predetermined pressure is 5N. In the pull-back test step, the predetermined speed is 0.5 mm / s.

7. The testing method according to claim 5 or 6, characterized in that: in, Select multiple temperatures in the temperature range of 20° C. to 1500° C. as the multiple target temperatures, repeat the above heating step to the ash adhesion strength calculation step for each target temperature, Prepare a plurality of groups of the bearing columns and the pressure columns made of different metal materials, and repeat the heating step to the ash adhesion strength calculation step for each group of the bearing columns and the pressure columns.

8. The testing method according to claim 5, characterized in that: in, The ash flakes are in the shape of round flakes. The tensile force data is the peak value of the tensile force. Repeat the constant temperature pressurizing step and the pull-back test step multiple times to obtain multiple tensile force peaks. In the ash adhesion strength calculation step, the average value of the plurality of tensile force peaks is calculated as the effective tensile force peak, and the adhesion strength is calculated based on the effective tensile force peak and the cross-sectional area of ​​the ash sheet: In the formula, F max is the effective tensile peak value, and S is the cross-sectional area of ​​the ash sheet.

9. The testing method according to claim 5, characterized in that: Before the heating step, the method further comprises: an end surface polishing step, polishing the upper end surface of the bearing column and the lower end surface of the pressure column to make them smooth; and The sensor calibration step comprises: heating the furnace to 500°C, 1000°C and 1500°C respectively, connecting weights of 0.05kg, 0.5kg and 5kg to the tension sensor at each temperature and calibrating the tension data measured by the sensor.

10. The testing method according to claim 5, characterized in that: Before the heating step, the method further comprises: The ash flake preparation step comprises placing ash-like powder corresponding to the boiler ash into a cylindrical mold, and uniaxially extruding the ash-like powder in the cylindrical mold for 300 seconds at a pressure of 20 MPa to form the ash flake. Wherein, in the ash sheet preparation step, a plurality of ash sheets of different materials are prepared, and the above-mentioned heating step to the ash adhesion strength calculation step are repeated for each of the ash sheets.

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