Porous medium material testing and evaluating device for porous medium combustion

Abstract

The invention relates to the field of porous medium material test and evaluation, in particular to a porous medium material test and evaluation device for porous medium combustion. The device comprises a porous medium burner, a gas supply pipeline, a smoke exhaust pipeline, a measuring system and a control system, wherein the measuring system comprises a flowmeter, a pressure sensor, a thermocouple, an infrared temperature sensor and a smoke component analysis sensor which are arranged in the gas supply pipeline and the smoke exhaust pipeline; and the control system is used for controlling the adjustment of each pipeline gas and controlling the temperature, the power density and the operation state of the porous medium combustor. The highest temperature of the combustion surface of the porous medium combustor is not lower than 1700 DEG C, the energy density is not lower than 2.0 MW / m < 2 >, and the measurement system can monitor the temperature of the combustion surface and the internal temperature of the porous medium in real time. The device provided by the invention is scientific and reasonable in design and standard in determination method, and can be used for objectively measuring and evaluating the porous medium material under variable working conditions and variable combustion working conditions.

Description

Technical Field

[0001] The present invention relates to the field of porous medium material tests and evaluations, and particularly to a porous medium material test and evaluation device for porous medium combustion. Background Art

[0002] With the development of mankind and the progress of technology, the rapid economic development of China requires a large amount of energy consumption, and the demand for energy is increasing day by day. The problem of energy shortage has also attracted more and more extensive attention. Improving the utilization efficiency can reduce consumption greenly and economically, which is the first choice for conservation. While the economy is developing rapidly, environmental protection needs to be taken into account, and a sustainable development path of coordinated development between humans and nature should be followed. Therefore, broadening the supply channels, exploring and developing low-grade or low-calorific value energy sources, seeking efficient and clean combustion technologies that are beneficial to environmental protection, energy conservation and emission reduction, realizing the efficient and reasonable utilization of energy, and achieving a "win-win" situation of economic growth and environmental protection are important strategic issues related to the long-term development of our country.

[0003] In recent years, many new combustion technologies have emerged continuously. Among them, the porous medium combustion technology has excellent characteristics and broad application prospects. In the process of porous medium combustion, the porous medium material plays a key role. The gas / solid two-phase region formed by the porous medium is not only the place where gas flows, but also the carrier for combustion and heat transfer. From the perspective of the combustion organization process, the working environment of the porous medium is highly corrosive, high temperature and high temperature gradient. Combining the porous medium combustion mechanism, the porous medium used in the burner must meet the following conditions: (1) High temperature resistance, no melting occurs within the combustion temperature range; (2) Appropriate porosity, so that the pressure loss is small when the mixed gas flows through it; (3) Thermal shock resistance, not damaged by thermal stress during the start and stop of combustion; (4) High infrared thermal emissivity and good thermal conductivity to improve the heat transfer efficiency of the burner.

[0004] With the development of the porous medium combustion technology, high-power density burners for high-temperature applications have received increasing attention in the industry. During the combustion process, the temperature is high, even reaching above 1450°C, and there may also be local high temperatures. The existence of temperature gradients causes thermal stress in the porous medium material. When the thermal stress accumulates to the material limit, the material will suddenly crack; and the water vapor and carbon dioxide in the flue gas generated by combustion cause serious high-temperature oxidation corrosion to the medium material, and the service life of the material will be greatly reduced. The above response behavior of the material during the combustion process has not been deeply studied by materials professionals in combination with the working conditions.

[0005] Develop a test and evaluation device for the medium materials used in porous medium combustion, which can not only verify different medium materials, but also control the combustion device and process to achieve changes in the temperature field and then generate different thermal stress fields, explore the mechanical response behavior of materials in different thermal stress fields, and also explore the mass transfer - heat transfer, combustion and pollutant emissions of different porous medium materials under different combustion conditions; it can also simulate the high-temperature flue gas environment, systematically study the high-temperature oxidation and corrosion behavior of materials under the working conditions of porous medium combustion, lay an experimental foundation for the development of new surface modification technologies for anti-smoke corrosion, and also obtain the adaptability laws of porous medium materials in the application of high-temperature porous medium combustion technology, lay a foundation for the development of long-life porous medium materials for industrial applications, which will greatly promote the progress of porous combustion technology and has important practical significance. Summary of the Invention

[0006] The object of the present invention is to provide a test and evaluation device for porous medium materials used in porous medium combustion, which solves the problem that the combination of porous medium materials and combustion conditions is not tight enough in the research and development process of existing porous medium combustion technologies, is used to test and characterize the service behavior of porous medium materials under different combustion conditions for objective evaluation, and guide the optimal design of porous medium materials; at the same time, it can also obtain combustion parameters according to different porous media for the design of burners, which is conducive to the in-depth research of porous medium materials and combustion technologies through the cross-integration of disciplines such as materials science, combustion science, and thermal energy engineering.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is:

[0008] A test and evaluation device for porous medium materials used in porous medium combustion, including a porous medium burner, a gas supply pipeline, a smoke exhaust pipeline, a measurement system and a control system, wherein: the measurement system is composed of flow meters, pressure sensors, thermocouples, infrared temperature sensors, and flue gas component analysis sensors provided in the gas supply pipeline and the smoke exhaust pipeline; the control system is used to control the adjustment of the gas in each pipeline, and control the temperature, power density and operating state of the porous medium burner.

[0009] The porous medium burner is provided with a wind distribution plate, a lining and a panel in the shell. The shell is an integral structure with a cylindrical barrel part and frustum-shaped barrel parts symmetrically provided at both ends. The upper end of the shell is provided with a smoke exhaust port, and an infrared temperature sensor is provided above the smoke exhaust port. The lower end of the shell is provided with an air inlet. The inner cavity of the cylindrical barrel part of the shell is installed with an annular lining and a panel from top to bottom. The central hole of the lining is installed with a porous medium material and a wind distribution plate from top to bottom. The thermocouple is inserted into the porous medium material. The space enclosed by the wind distribution plate and the lining serves as a gas distribution chamber.

[0010] The gas supply pipeline is provided with a gas pipeline, a combustion-supporting air pipeline, a gas / air mixer and a premixed gas regulating valve. The gas pipeline and the combustion-supporting air pipeline are connected in parallel and then connected to the air inlet of the porous medium burner through a pipeline provided with a gas / air mixer and a premixed gas regulating valve;

[0011] The exhaust gas pipeline is arranged at the side of the exhaust port. One end of it is connected to the smoke port, and the other end is provided with a flue gas composition analysis sensor to analyze the flue gas emission conditions under different porous media and different working conditions, and to characterize the differences in pollutant reduction of materials.

[0012] For the porous medium material test and evaluation device for porous medium combustion, the air distribution plate is composed of mullite or alumina polycrystalline fiber board, and ventilation holes are arranged on it. The ventilation holes on the air distribution plate are uniformly arranged holes or non-uniformly arranged holes. Uniformly arranged holes or non-uniformly arranged holes corresponding to the air distribution plate are opened on the panel. A wind distribution chamber is formed between the panel and the lower frustum-shaped cylinder part of the porous medium burner. A wind distribution chamber pressure sensor is inserted into the wind distribution chamber. By adjusting the distribution density of the ventilation holes in different regions, the distribution difference of the premixed gas flow rate is formed in different regions of the panel, and different temperature distributions are formed after combustion. Furthermore, the ability of the material to resist thermal stress mismatch is characterized by the artificially created non-uniform temperature field.

[0013] For the porous medium material test and evaluation device for porous medium combustion, a gas source, a gas pressure regulating valve, a gas screwing valve, an air flow meter and an electromagnetic cut-off valve are successively arranged on the gas pipeline, and then connected to the gas / air mixer; a variable frequency speed regulating fan, a fan valve, a pressure stabilizing tank and an air flow meter are successively arranged on the combustion-supporting air pipeline, and then connected to the gas / air mixer.

[0014] For the porous medium material test and evaluation device for porous medium combustion, gas is provided by the gas source, and combustion-supporting air is generated by the variable frequency speed regulating fan. After the gas and the combustion-supporting air enter the gas / air mixer and are mixed to form a premixed gas, it is then connected to the porous medium burner through a metal hose; the air flow rate in the combustion-supporting air pipeline is adjusted by the frequency conversion of the variable frequency speed regulating fan, and then associated with the air flow meter of the gas pipeline through a proportional relationship to realize the linkage adjustment of the air-gas flow ratio, and the power density is adjusted by the flow rate adjustment.

[0015] For the porous medium material test and evaluation device for porous medium combustion, the control system is provided with a computer, a data collector and a flow meter controller. The input end of the flow meter controller is connected to the air flow meter through a line, and the output end of the flow meter controller and the thermocouple are respectively connected to the input end of the data collector through lines. The output end of the data collector is connected to the input end of the computer through a line, and the output end of the flue gas composition analysis sensor is connected to the input end of the computer through a line.

[0016] The test and evaluation device for porous medium materials used in porous medium combustion enables the control system to achieve stable combustion. Different combustion conditions with different power densities are achieved through flow regulation, thereby forming different combustion temperatures to evaluate the long-term resistance of the materials to flue gas erosion.

[0017] The test and evaluation device for porous medium materials used in porous medium combustion enables the control system to achieve a variable-temperature cycle combustion condition. Different temperature changes are achieved through flow regulation during the cycle, realizing the reciprocating change of the temperature of the porous panel from low to high and then to low, to evaluate the anti-cycle thermal shock ability of the materials.

[0018] The test and evaluation device for porous medium materials used in porous medium combustion enables the control system to calibrate the wind speed for steady combustion of the porous medium materials in the burner through flow regulation, and then obtain the combustion limits of different porous media.

[0019] The design concept of the present invention is:

[0020] The device of the present invention includes a porous medium burner, a gas supply pipeline, an exhaust pipeline, a measurement system and a control system. The porous medium burner can quickly replace the porous medium materials. The gas supply pipeline can achieve complete premixing of gas and air, and the flue gas composition can be analyzed through the exhaust pipeline. The maximum temperature of the combustion surface of the porous medium burner is not lower than 1700 °C, and the energy density is not lower than 2.0 MW / ㎡. The measurement system can monitor the temperature of the combustion surface and the internal temperature of the porous medium in real time, and can also analyze the composition of NO X , CO, CO2, H2O, etc. in the flue gas. Parameters such as air-fuel ratio, power density, and combustion limit are obtained through monitoring the gas flow rate and air flow rate; stable combustion or variable-temperature cycle combustion conditions can be carried out through the control system, which can be used for the research of material combustion characteristics and the evaluation of the resistance to high-temperature flue gas erosion and thermal shock. Thus, disciplines such as materials science, combustion science, and thermal energy engineering are cross-integrated, and the application and development of porous medium combustion technology and porous medium materials are combined, which can promote the development and progress of porous medium combustion technology through the innovation of material technology.

[0021] The advantages and beneficial effects of the present invention are:

[0022] 1. The test and evaluation device for medium materials used in porous medium combustion of the present invention will generate different combustion conditions according to different combustion environments, explore the response behavior of the medium materials in the combustion environment, and provide theoretical guidance for material design, preparation and burner design.

[0023] 2. The present invention can obtain different temperature fields. In the design, the gas flow rate in different regions of the combustion surface can be controlled by changing the hole density of the gas distribution plate, thereby generating different temperature gradients to investigate the anti-thermal stress mismatch ability of the materials.

[0024] 3. The device parameters of the present invention are high, and the maximum power density ≥ 2.0 MW / m 2 , and the highest combustion surface temperature is not lower than 1700 °C. There is no report on the relevant dielectric material test equipment, which is much higher than the combustion power and temperature reported in the research devices related to porous medium combustion in the literature (< 1.7 MW / m 2 , < 1400 °C).

[0025] 4. In the control mode of the present invention, stable combustion can be carried out. Different combustion conditions with different power densities are achieved through flow regulation, and then different combustion temperatures are formed, which can evaluate the long-term resistance of materials to flue gas erosion; the variable-temperature cyclic combustion condition can also be realized. Different temperature changes are achieved through flow regulation during the cycle, and the reciprocating change of the porous panel temperature from low to high and then to low can be realized, which can evaluate the resistance of materials to cyclic thermal shock. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic structural diagram of a test and evaluation device for porous medium materials for porous medium combustion.

[0027] In the figure, 1 is a variable-frequency speed-regulating fan, 2 is a fan valve, 3 is a pressure stabilizing tank, 4 is an air flowmeter, 5 is a gas / air mixer, 6 is a premixed gas regulating valve, 7 is a porous medium burner, 8 is a wind distribution plate, 9 is a porous medium material, 10 is a thermocouple, 11 is a flue gas component analysis sensor, 12 is a computer, 13 is a data collector, 14 is a flowmeter controller, 15 is an infrared temperature sensor, 16 is a gas pressure regulating valve, 17 is a gas screw valve, 18 is an electromagnetic cut-off valve, 19 is a gas source, and 20 is a wind distribution chamber pressure sensor.

[0028] Figure 2 It is a schematic structural diagram of a porous medium burner. In the figure: 8 is a wind distribution plate, 9 is a porous medium material, 21 is a housing, 22 is a lining, 23 is a smoke exhaust port, 24 is a panel, 25 is a densely arranged hole, and 26 is an air inlet.

[0029] Figures 3 - 4 They are two hole arrangement methods of the wind distribution plate. Among them, Figure 3 is the uniform hole arrangement, Figure 4 is the non-uniform hole arrangement. DETAILED DESCRIPTION OF THE INVENTION

[0030] As Figures 1 - 4As shown in the figure, a test and evaluation device for porous medium materials used in porous medium combustion includes a porous medium burner 7, a gas supply pipeline, a smoke exhaust pipeline, a measurement system and a control system. Among them: The measurement system is composed of flow meters, pressure sensors, thermocouples, infrared temperature sensors 15, and flue gas component analysis sensors 11 installed in the gas supply pipeline and the smoke exhaust pipeline; The control system is used to control the regulation of the gas in each pipeline, and to control the temperature, power density and operating state of the porous medium burner 7.

[0031] The porous medium burner 7 is provided with a wind distribution plate 8, a lining 22 and a panel 24 inside the housing 21. The housing 21 is an integrated structure with cylindrical barrel parts at both ends symmetrically provided with frustum-shaped barrel parts. The upper end of the housing 21 is provided with a smoke exhaust port 23, and an infrared temperature sensor 15 is provided above the smoke exhaust port 23. The lower end of the housing 21 is provided with an air inlet 26. The inner cavity of the cylindrical barrel part of the housing 21 is installed with an annular lining 22 and a panel 24 from top to bottom. The central hole of the lining 22 is installed with a porous medium material 9 and a wind distribution plate 8 from top to bottom. The thermocouple 10 is inserted into the porous medium material 9. The space surrounded by the wind distribution plate 8 and the lining 22 serves as a gas distribution chamber. The wind distribution plate 8 is composed of mullite or alumina polycrystalline fiber board, and ventilation holes are arranged on it. The ventilation holes on the wind distribution plate 8 are uniformly arranged holes ( Figure 3 ) or non-uniformly arranged holes ( Figure 4 ). The panel 24 is provided with closely arranged holes 25 (uniformly closely arranged holes or non-uniformly closely arranged holes) corresponding to the wind distribution plate 8. A wind distribution chamber is formed between the panel 24 and the lower frustum-shaped barrel part of the porous medium burner 7. The wind distribution chamber pressure sensor 20 is inserted into the wind distribution chamber. By adjusting the distribution density of the ventilation holes in different regions, the distribution difference of the premixed gas flow is formed in different regions of the panel, and different temperature distributions are formed after combustion. Furthermore, the ability of the material to resist thermal stress mismatch is characterized by the artificially created non-uniform temperature field;

[0032] The gas supply pipeline is provided with a gas pipeline, a combustion-supporting air pipeline, a gas / air mixer 5 and a premixed gas regulating valve 6. The gas pipeline and the combustion-supporting air pipeline are connected in parallel and then connected to the air inlet 26 of the porous medium burner 7 through a pipeline (on which there are a gas / air mixer 5 and a premixed gas regulating valve 6); successively arranged on the gas pipeline are a gas source 19, a gas pressure regulating valve 16, a gas screw valve 17, an air flow meter, and an electromagnetic cut-off valve 18, and then it is connected to the gas / air mixer; successively arranged on the combustion-supporting air pipeline are a variable-frequency speed-regulating fan 1, a fan valve 2, a pressure stabilizing tank 3, an air flow meter 4, and then it is connected to the gas / air mixer; the gas is provided by the gas source 19, and the combustion-supporting air is generated by the variable-frequency speed-regulating fan 1. After the gas and the combustion-supporting air enter the gas / air mixer for mixing, a premixed gas is formed, and then it is connected to the porous medium burner 7 through a metal hose; the air flow in the combustion-supporting air pipeline is adjusted by the frequency conversion of the variable-frequency speed-regulating fan 1, and then it is associated with the air flow meter 4 of the gas pipeline through a proportional relationship to realize the linkage adjustment of the air-gas flow ratio, and the power density is adjusted by the flow adjustment;

[0033] The smoke exhaust pipeline is arranged on the side of the smoke outlet 23. One end of it is connected to the smoke outlet 23, and the other end is provided with a flue gas component analysis sensor 11, which can analyze the flue gas emission conditions under different porous media and different working conditions, and characterize the differences of materials in terms of pollutant reduction;

[0034] The control system is provided with a computer 12, a data collector 13, and a flow meter controller 14. The input end of the flow meter controller 14 is connected to the air flow meter through a line, the output end of the flow meter controller 14 and the thermocouple 10 are respectively connected to the input end of the data collector 13 through lines, the output end of the data collector 13 is connected to the input end of the computer 12 through a line, and the output end of the flue gas component analysis sensor 11 is connected to the input end of the computer 12 through a line.

[0035] The control system can achieve stable combustion, realize combustion conditions with different power densities through flow adjustment, and then form different combustion temperatures, and can evaluate the long-term flue gas erosion resistance of materials; it can also realize a variable-temperature cycle combustion condition, realize different temperature changes through flow adjustment during the cycle, and can realize the reciprocating change of the porous panel temperature from low to high and then to low, and can evaluate the anti-cycle thermal shock ability of materials; the control system can calibrate the wind speed for the porous medium material to achieve steady combustion in the burner through flow adjustment, and then obtain the combustion limits of different porous media.

[0036] Next, the working conditions of the device will be specifically described according to different test purposes:

[0037] First, the steady-state combustion conditions under different power density and combustion surface temperature conditions are obtained (the burner combustion surface size is 200×200mm, and the gas is methane). The specific operation process is as follows:

[0038] Open the fan valve 2, open the premixed gas regulating valve 6, start the variable frequency speed regulating fan 1, adjust the fan frequency, observe the measured value of the air flow meter 4 until the air volume reaches the required value; adjust the gas pressure regulating valve 16 to the required gas pressure, open the electromagnetic stop valve 18, and adjust the gas rotary valve 17. At this point, the premixed gas after the gas and air are mixed by the gas / air mixer 5 enters the air distribution chamber of the porous medium burner 7 and flows out from the panel 24 of the porous medium burner 7.

[0039] When high-pressure pulse ignition is turned on, the premixed gas will flow out of the panel 24 of the porous medium burner 7. At this time, the gas / air ratio is adjusted to a suitable value, and the flame will burn in the porous medium material 9 to achieve the combustion of the porous medium material. The equivalent ratio is controlled to be 0.8, and the gas flow rate and air flow rate are adjusted respectively, and then the burner power density and temperature.

[0040] Power density (mw / ㎡) 0.5 0.8 1.2 1.5 2.1 Combustion surface temperature (℃) 700 900 1000 1400 1700

[0041] Example 1: Material testing

[0042] (1) Durability test: Use a uniformly arranged air distribution plate, select the porous medium material to be tested, such as Si-SiC foam, load the porous medium material into the porous medium burner, adjust the temperature of the porous medium burner to 1400℃, and burn for 400 hours under steady-state conditions. After the test time is over, remove the Si-SiC foam, observe the surface and fracture structure of the material through a scanning electron microscope, and obtain the high-temperature flue gas erosion of the material through the changes in the grain structure on the surface and in the fracture; use diamond cutting to take mechanical property samples before and after the foam material test, and conduct mechanical property tests. The performance attenuation of the material after high-temperature service can be obtained through the changes in mechanical properties. The experiment simulates the service conditions of the material during the long-term use of the actual thermal industrial equipment, and the service life of the material can be inferred.

[0043] (2) Thermal shock resistance test: An evenly perforated air distribution plate is used. Select the porous medium material to be tested, such as Si-SiC foam. After loading the porous medium material into the porous medium burner, adjust the temperature of the porous medium burner to 1400 °C. Shut down the gas electromagnetic cut-off valve to stop combustion. Air continues to flow into the porous medium burner. After the sample is cooled to 200 °C by air cooling, then open the gas electromagnetic cut-off valve, ignite, and heat up to 1400 °C, then close the gas electromagnetic cut-off valve. Repeat this cycle 200 times. The cycle process is automatically realized by the control system. After the cycle is completed, remove the Si-SiC foam, observe the surface and fracture microstructure of the material through a scanning electron microscope, and obtain the internal changes of the material after cyclic thermal shock through the changes in the grain microstructure on the surface and in the fracture. Through the generation and distribution of surface and internal thermal cracks, combined with the changes in mechanical properties, the thermal shock resistance of the material can be evaluated. The experiment simulates the ignition-shutdown-ignition cycle during the actual operation of thermal industrial devices.

[0044] (3) Thermal stress mismatch resistance: An unevenly perforated air distribution plate is used. Select the porous medium material to be tested. After loading the porous medium material into the porous medium burner and igniting to enter the porous medium combustion state, adjust the gas flow rate. In this way, the gas flow rate in the area with dense perforations on the air distribution plate is large, and the combustion heat is high, resulting in a higher combustion temperature than in the area with sparse perforations. The temperature difference between the two areas can be obtained by observing with an infrared temperature sensor. Due to the temperature difference, the thermal expansion degree of the porous medium material is different in different temperature areas, and its elastic deformation is different, thus generating internal thermal stress. When the temperature difference reaches a certain level and the internal stress exceeds the material's bearing limit, an internal stress mismatch phenomenon occurs, and then failure occurs. The experiment can evaluate the thermal stress mismatch limit of different materials by measuring the temperature difference that the material can withstand, which can be used to guide the optimized design of the burner structure.

[0045] Example 2: Combustion technology development and burner design based on porous medium materials

[0046] (1) Measurement of the combustion limit of the material: An evenly perforated air distribution plate is used. According to the burner design requirements, select the porous medium material to be used, such as Si-SiC foam (20 PPI, 20 mm thickness). After loading the porous medium material into the porous medium burner, ignite and conduct steady-state combustion. Fix the equivalence ratio at 0.7 and reduce the flow rate of the premixed gas. At this time, the wind speed decreases. When it reaches a certain level, stable combustion cannot be maintained, and flashback will occur at this time. Obtain the flashback critical value, divide the flow rate at this time by the combustion area, and obtain the lower limit of the combustion flow velocity; increase the flow rate of the premixed gas. At this time, the wind speed increases. When the wind speed is too high, stable combustion cannot be maintained, and the flame is blown out. Obtain the blowout critical value, divide the flow rate at this time by the combustion area, and obtain the upper limit of the combustion flow velocity.

[0047] By varying the equivalence ratio and repeating the above process, the combustion limits of the porous medium material under different equivalence ratio conditions can be obtained. Furthermore, the burner can be designed using the relevant porous medium material based on the measurement of the above combustion limits.

[0048] According to the requirements of the combustion device, porous medium materials with different sizes and configurations can be used, such as porous medium materials with 10 PPI / 30 mm thickness and 15 PPI / 25 mm thickness. Pure SiC foam, zirconia foam, and alumina foam with different materials can also be used for testing. Finally, the most suitable configuration and design of the porous medium material required for the combustion device can be obtained.

[0049] (2) Measurement of pollutant emissions:

[0050] Using a uniformly perforated air distribution plate, according to the design requirements of the burner, select the porous medium material to be used, such as Si-SiC foam (20 PPI, 20 mm thickness). After loading the porous medium material into the porous medium burner, ignite it and conduct combustion under steady-state conditions. Fix the equivalence ratio at 0.7, adjust the flow rate of the mixed gas to different steady-state combustion temperatures, and measure the components of the flue gas emitted at this time. The NOx and CO concentrations in the flue gas under different temperature conditions can be obtained. By varying the equivalence ratio and repeating the above process, the pollutant emission values under different equivalence ratio conditions can be obtained.

[0051] The selection of the porous medium material can be evaluated by measuring the pollutant emissions during the combustion of porous medium materials with different materials and structures.

[0052] The implementation results show that the device of the present invention is scientifically and reasonably designed, and the measurement method is standardized. It can objectively measure and evaluate the porous medium material under variable working conditions and variable combustion conditions.

[0053] The above embodiments of the present invention are only examples for clearly illustrating the present invention, and are not intended to limit the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And these obvious changes or modifications derived from the essential spirit of the present invention still fall within the protection scope of the present invention.

Claims

1. A test and evaluation device for porous medium materials used in porous medium combustion, characterized in that It includes a porous medium burner, a gas supply pipeline, a smoke exhaust pipeline, a measurement system and a control system. Among them: The measurement system includes flow meters, pressure sensors, thermocouples, infrared temperature sensors, and flue gas composition analysis sensors installed in the gas supply pipeline and the smoke exhaust pipeline; The control system is used to control the regulation of the gas in each pipeline, and to control the temperature, power density and operating state of the porous medium burner; The porous medium burner is provided with a wind distribution plate, a lining and a panel in the shell. The shell is an integral structure with a cylindrical barrel part and frustum-shaped barrel parts symmetrically provided at both ends. A smoke exhaust port is provided at the upper end of the shell, and an infrared temperature sensor is provided above the smoke exhaust port. An air inlet is provided at the lower end of the shell. The inner cavity of the cylindrical barrel part of the shell is installed with an annular lining and a panel from top to bottom. The central hole of the lining is installed with a porous medium material and a wind distribution plate from top to bottom. The thermocouple is inserted into the porous medium material. The space enclosed by the wind distribution plate and the lining serves as a gas distribution chamber; The gas supply pipeline is provided with a gas pipeline, a combustion-supporting air pipeline, a gas / air mixer and a premixed gas regulating valve. The gas pipeline and the combustion-supporting air pipeline are connected in parallel and then connected to the air inlet of the porous medium burner through a pipeline provided with a gas / air mixer and a premixed gas regulating valve; The smoke exhaust pipeline is arranged at the side of the smoke exhaust port. One end of it is connected to the smoke port, and the other end is provided with a flue gas composition analysis sensor to analyze the smoke emission conditions under different porous media and different working conditions, and to characterize the differences in pollutant emission reduction of materials.

2. The porous medium material test and evaluation device for porous medium combustion according to claim 1, characterized in that, The wind distribution plate is composed of mullite or alumina polycrystalline fiber board, and ventilation holes are arranged on it. The ventilation holes on the wind distribution plate are uniformly arranged holes or non-uniformly arranged holes. Uniformly arranged holes or non-uniformly arranged holes corresponding to the wind distribution plate are opened on the panel. A wind distribution chamber is formed between the panel and the lower frustum-shaped barrel part of the porous medium burner. A wind distribution chamber pressure sensor is inserted into the wind distribution chamber. By adjusting the distribution density of the ventilation holes in different regions, the distribution difference of the premixed gas flow is formed in different regions of the panel, and different temperature distributions are formed after combustion. Furthermore, the ability of the material to resist thermal stress mismatch is characterized by the artificially created non-uniform temperature field.

3. The porous medium material test and evaluation device for porous medium combustion according to claim 1, characterized in that A gas source, a gas pressure regulating valve, a gas screw valve, an air flow meter, and an electromagnetic cut-off valve are successively arranged on the gas pipeline, and then connected to the gas / air mixer; A variable frequency speed regulating fan, a fan valve, a pressure stabilizing tank, and an air flow meter are successively arranged on the combustion-supporting air pipeline, and then connected to the gas / air mixer.

4. The porous medium material test and evaluation device for porous medium combustion according to claim 3, characterized in that, The gas is provided by the gas source, and the combustion-supporting air is generated by the variable frequency speed regulating fan. The gas and the combustion-supporting air enter the gas / air mixer to be mixed to form a premixed gas, and then are connected to the porous medium burner through a metal hose; The air flow in the combustion-supporting air pipeline is adjusted by the frequency conversion of the variable frequency speed regulating fan, and then is associated with the air flow meter of the gas pipeline through a proportional relationship to realize the linkage adjustment of the air-gas flow ratio, and the power density is adjusted by the flow adjustment.

5. The porous medium material test and evaluation device for porous medium combustion according to claim 1, characterized in that, The control system is equipped with a computer, a data collector, and a flowmeter controller. The input end of the flowmeter controller is connected to an air flowmeter through a line. The output end of the flowmeter controller and a thermocouple are respectively connected to the input end of the data collector through lines. The output end of the data collector is connected to the input end of the computer through a line. The output end of the flue gas composition analysis sensor is connected to the input end of the computer through a line.

6. The porous medium material test and evaluation device for porous medium combustion according to claim 1 or 5, characterized in that, The control system realizes stable combustion, achieves combustion conditions with different power densities through flow regulation, and then forms different combustion temperatures to evaluate the long-term resistance of materials to flue gas erosion.

7. The porous medium material test and evaluation device for porous medium combustion according to claim 1 or 5, characterized in that, The control system realizes a variable-temperature cycle combustion condition, achieves different temperature changes through flow regulation during the cycle, realizes the reciprocating change of the temperature of the porous panel from low to high and then to low, and evaluates the resistance of materials to cyclic thermal shock.

8. The porous medium material test and evaluation device for porous medium combustion according to claim 1 or 5, characterized in that The control system calibrates the wind speed for the steady combustion of porous medium materials in the burner through flow regulation, and then obtains the combustion limits of different porous media.

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