Combustion heat exchange experiment device and method

Abstract

The invention relates to the technical field of combustion and discloses a combustion heat exchange experimental device and method.The combustion heat exchange experimental device comprises a furnace body, a plurality of gas supply systems independent of one another, a gas burner, a solid material supply system, a flue gas treatment system, a heat exchange system and a measuring system; the gas supply system is connected with the furnace body to supply different gas media into the furnace body, the gas burner is connected with the furnace body and the gas supply system and can serve as a channel to supply the gas media into the furnace body or burn the gas media to heat the furnace body, and the solid material supply system is used for conveying solid fuel and / or bed materials to the furnace body. The flue gas treatment system can adjust the back pressure of the furnace body, the heat exchange system can transfer heat in the furnace body, and the measuring system can measure heat exchange parameters of different areas in the furnace body. According to the combustion heat exchange experimental device disclosed by the embodiment of the invention, stable combustion experiments of various materials in a high-pressure oxygen-enriched environment can be realized, and heat exchange parameters can be measured to provide data reference for furnace body optimization.

Description

Technical Field

[0001] This invention belongs to the field of combustion technology, specifically relating to a combustion heat exchange experimental apparatus and method. Background Technology

[0002] Pressurized oxy-fuel combustion systems operate under high pressure throughout the entire process, which can significantly reduce energy consumption. However, the related technologies are still in the experimental stage, with research limited to combustion characteristics and pollutant emissions. Core challenges such as heat transfer and heating surface arrangement have not yet been addressed through heat exchange studies specifically for actual fluidized bed pressurized oxy-fuel combustion furnace operations. Furthermore, most related technologies utilize small-scale, laboratory-grade equipment, suitable only for testing small sample fuels and unable to simulate industrial conditions. Additionally, they are limited to single-fuel systems, adaptable only to either solid or gaseous fuels. Summary of the Invention

[0003] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, embodiments of this invention propose a combustion heat exchange experimental device. This device can perform experiments on the stable combustion of various materials under high pressure and oxygen-rich conditions, as well as fluidized bed combustion, reaching the hundreds of kilowatt level. It can also measure heat exchange parameters under various combustion environments to provide data reference for furnace optimization.

[0004] This invention also proposes a combustion heat transfer experimental method that enables seamless switching between preheating, gas combustion, and solid combustion, providing convenience for obtaining heat transfer parameter measurements during various stable combustion processes.

[0005] The combustion heat exchange experimental apparatus of this invention includes a furnace body, multiple independent gas supply systems, a gas burner, a solid material supply system, a flue gas treatment system, a heat exchange system, and a measurement system. The multiple gas supply systems are connected to the furnace body to supply at least one different gaseous medium to the furnace body. The gas burner is connected to the furnace body, and the gas supply systems are connected to the gas burner. The gas burner can serve as a channel to supply the gaseous medium from the gas supply system into the furnace body, or the gaseous medium from the gas supply system can enter the gas burner for combustion. The heat medium (flue gas) generated by combustion enters the furnace body to heat it. The solid material supply system is connected to the furnace body for supplying solid fuel and / or bed material to the furnace body. The flue gas treatment system is connected to the furnace body for adjusting the back pressure of the furnace body and purifying the flue gas discharged from the furnace body. The heat exchange system is connected to the furnace body for transferring heat from different areas within the furnace body. The measurement system is connected to the heat exchange system for measuring the heat exchange parameters of different areas within the furnace body.

[0006] The combustion heat exchange experimental apparatus of this invention integrates an independent gas supply system, a gas burner, a solid material supply system, a flue gas treatment system, and a heat exchange system, enabling pressurized oxygen-enriched combustion and heat exchange experiments of multiple fuels (gas and solid) on a single experimental platform. Its hundreds of kilowatts of thermal power (50... (200KW) can simulate local operating conditions of industrial boilers and support pilot-scale experiments; it uses a mixture of oxygen and carbon dioxide as the combustion medium, directly matching the carbon capture scenario, and can achieve carbon dioxide enrichment in flue gas; it also has complete combustion capabilities. heat exchange Measurement The closed-loop flue gas treatment system allows for direct heat exchange studies under actual furnace conditions, overcoming the limitations of traditional laboratory equipment, such as small scale, limited fuel compatibility, and lack of integrated carbon capture simulation.

[0007] In some embodiments, the furnace body includes a furnace chamber, an air distribution plate, a gas chamber, a first air inlet, a guide tube, and a third air inlet. The air distribution plate is disposed in the lower part of the furnace chamber and is provided with a plurality of fluidizing nozzles. The gas chamber is located below the air distribution plate and the plurality of fluidizing nozzles are in communication with the gas chamber. The first air inlet is in communication with the gas chamber. The outlet of the gas burner is in communication with the first air inlet. The guide tube passes through the gas chamber and the air distribution plate. The upper end of the guide tube is placed inside the furnace chamber, and the lower end of the guide tube forms a second air inlet. The third air inlet is located in the middle region of the furnace body and is in communication with the furnace chamber.

[0008] In some embodiments, the plurality of gas supply systems include a first gas supply system and a third gas supply system, the first gas supply system being used to provide a mixture of oxygen and carbon dioxide, and the third gas supply system being used to provide fuel gas, the fuel gas including at least one of dimethyl ether, natural gas, methane, and propane.

[0009] In some embodiments, the plurality of gas supply systems include a second gas supply system for providing air.

[0010] In some embodiments, the plurality of gas supply systems include a fourth gas supply system for providing a protective gas, the protective gas being at least one of nitrogen, argon, and helium.

[0011] In some embodiments, the first gas supply system includes an oxygen supply device, a carbon dioxide supply device, a premixing tank, a mixed gas storage tank, and a pressurizing device. The oxygen supply device and the carbon dioxide supply device are used to supply oxygen and carbon dioxide, respectively. The oxygen supply device and the carbon dioxide supply device are connected to the premixing tank so that the oxygen and the carbon dioxide enter the premixing tank for premixing. The premixing tank is connected to the mixed gas storage tank for storing the mixed gas. The pressurizing device is disposed between the premixing tank and the mixed gas storage tank for bringing the pressure of the mixed gas in the mixed gas storage tank to a target value.

[0012] In some embodiments, the output of the mixed gas storage tank is divided into two paths and connected to the third air inlet and the gas burner, respectively.

[0013] In some embodiments, the third gas supply system is divided into two paths and connected to the second air inlet and the gas burner, respectively.

[0014] In some embodiments, the solid material supply system includes a receiving device, a pressurizing chamber, and a feeder. The receiving device is used to receive the solid fuel and / or the bed material. The pressurizing chamber is connected to the receiving device to receive and pressurize the solid fuel and / or the bed material from the receiving device. The feeder is connected to the pressurizing chamber and the furnace body to transport the solid fuel and the bed material to the furnace chamber.

[0015] In some embodiments, the flue gas treatment system includes, in sequence along the flue gas flow direction, a cyclone separator, a heat exchange assembly, a dust collector, and a pressure regulating valve, wherein the bottom of the cyclone separator is provided with an ash tank, and the pressure regulating valve is used to regulate the back pressure of the furnace body.

[0016] In some embodiments, the heat exchange system includes: a plurality of heat exchangers and a plurality of heat exchange probes, wherein the heat exchangers are placed inside the furnace body, the heat exchange probes are connected to the measurement system, and the heat exchange probes are disposed in the dense phase region, splash region, dilute phase region and flue gas outlet region of the furnace body. The heat exchange probes are U-shaped tube structures, and thermocouples for measuring the tube wall temperature are disposed on their tube walls.

[0017] In some embodiments, the heat exchange system further includes a cooler, and a plurality of the heat exchangers and a plurality of the heat exchange probes are connected to the cooler via pipes to allow heat exchange medium within the cooler to flow between the cooler, the heat exchangers, and the heat exchange probes.

[0018] The combustion heat exchange experimental device of this invention, through optimized furnace structure design (such as with air distribution plate, gas chamber, multiple air inlets, guide tube, etc.), flexible configuration of multi-way gas supply system (supporting oxygen / carbon dioxide mixture, fuel gas, air, and protective gas), continuous pressurized conveying of solid materials, back pressure regulation and purification of flue gas treatment system, and heat exchange probes and heat exchangers that can be arranged in multiple areas inside the furnace, constructs a system capable of operating under high pressure (0 This is a comprehensive experimental platform simulating industrial fluidized bed or pulverized coal combustion conditions at 1.6 MPa. It enables flexible switching and mixed combustion of gaseous and solid fuels, operating entirely in an oxygen-enriched environment, directly supporting carbon capture technology research. Simultaneously, through real-time heat transfer measurements at multiple locations and with multiple parameters, it provides realistic and reliable experimental data on the heating surface arrangement and heat transfer of pressurized oxygen-enriched combustion boilers, filling the current gap in this field regarding heat transfer research under actual furnace conditions.

[0019] The combustion heat exchange experimental method of this invention is implemented by the combustion heat exchange experimental device of any of the above embodiments, including a preheating step: fuel gas and air are supplied to the gas burner through the two gas supply systems respectively so that the fuel gas and the air are burned in the gas burner and the furnace body is preheated until the furnace body reaches the preheating temperature, and then the gas supply system is stopped from supplying the fuel gas to the gas burner.

[0020] Gas combustion steps: The fuel gas is supplied to the furnace body through the gas supply system, the air supply is gradually stopped, and the mixture of oxygen and carbon dioxide is supplied to the furnace body through the gas burner through the gas supply system, so that the fuel gas and the mixture are stably burned in the furnace body; Solid combustion step: The fuel gas supplied to the furnace is gradually reduced through the gas supply system, and solid fuel is supplied to the furnace through the solid material supply system, so that the solid fuel and the mixed gas can burn stably in the furnace; Parameter measurement steps: Under the stable combustion state of the gas combustion step or the solid combustion step, the heat transfer parameters of different regions inside the furnace are measured by the measurement system; In the gas combustion step and the solid combustion step, the back pressure of the furnace body is adjusted by the flue gas treatment system to maintain the furnace body at the target pressure and ensure stable combustion. When the solid fuel is coal particles, a preparatory step is included before the preheating step: introducing bed material into the furnace body through the solid material supply system.

[0021] The combustion heat transfer experimental method of this invention fully utilizes the characteristics of the experimental device, including independent supply of multiple gas sources, multiple air inlets, continuous pressurized feeding, and adjustable back pressure. It achieves various combustion states from system preheating, stable combustion of gaseous fuels, and solid fuels, and can seamlessly connect the various steps. This method is specifically designed for pressurized oxy-fuel combustion conditions, and can safely and effectively obtain combustion characteristic data and key local heat transfer coefficients of various fuels, including gaseous and solid fuels, in a simulated industrial furnace environment. It provides a systematic experimental research method for overcoming the challenges of optimizing the heat transfer surface arrangement and design of pressurized oxy-fuel combustion boilers. Attached Figure Description

[0022] Figure 1 This is an overall schematic diagram of the combustion heat exchange experimental device according to an embodiment of the present invention.

[0023] Figure 2 This is a schematic diagram showing the coordination between the second, third, and fourth gas supply systems and the furnace body in the combustion heat exchange experimental device of this embodiment of the invention.

[0024] Figure 3 This is a schematic diagram of the first gas supply system in the combustion heat exchange experimental device of this invention.

[0025] Figure 4 This is a schematic diagram of the heat exchange system and the furnace body in the combustion heat exchange experimental device of this invention.

[0026] Figure 5 This is a schematic diagram of the flue gas treatment system in the combustion heat exchange experimental device of this invention.

[0027] Figure 6 This is a schematic diagram of the solid material supply system in the combustion heat exchange experimental apparatus of this invention.

[0028] Figure label: 1. Furnace body; 11. Furnace chamber; 12. Air distribution plate; 13. Fluidizing nozzle; 14. Gas chamber; 15. First air inlet; 16. Guide tube; 17. Second air inlet; 18. Third air inlet; 19. Detection unit; 2. Gas supply system; 21. First gas supply system; 211. Oxygen supply device; 212. Carbon dioxide supply device; 213. Premixing tank; 214. Mixed gas storage tank; 215. Pressurization device; 22. Second gas supply system; 23. Third gas supply system; 24. Fourth gas supply system; 3. Gas burner; 4. Solid material supply system; 41. Receiving device; 42. Pressurization chamber; 43. Feeder; 5. Flue gas treatment system; 51. Cyclone separator; 52. Heat exchanger assembly; 53. Dust collector; 54. Pressure regulating valve; 55. Ash hopper; 56. Flue gas sampling port; 6. Heat exchange system; 61. Heat exchanger; 62. Heat exchange probe; 63. Cooler. Detailed Implementation

[0029] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0030] like Figures 1-6 As shown, the combustion heat exchange experimental device of this invention includes a furnace body 1, multiple independent gas supply systems 2, a gas burner 3, a solid material supply system 4, a flue gas treatment system 5, a heat exchange system 6, and a measurement system. The multiple gas supply systems 2 are connected to the furnace body 1 to supply at least different gaseous media into the furnace body 1. The gas burner 3 is connected to the furnace body 1, and the gas supply systems 2 are connected to the gas burner 3. The gas burner 3 can serve as a channel to supply the gaseous media from the gas supply systems 2 into the furnace body 1, or the gaseous media from the gas supply systems 2 can enter the gas burner 3 for combustion. The heat generated by combustion enters the furnace body 1 to heat it. The solid material supply system 4 is connected to the furnace body 1 and is used to deliver solid fuel and / or bed material to the furnace body 1. The flue gas treatment system 5 is connected to the furnace body 1 and is used to adjust the back pressure of the furnace body 1 and purify the flue gas discharged from the furnace body 1. The heat exchange system 6 is connected to the furnace body 1 and is used to transfer heat from different areas within the furnace body 1. The measurement system is connected to the heat exchange system 6 and is used to measure the heat exchange parameters of different areas within the furnace body 1.

[0031] This embodiment provides a combustion heat transfer experimental device for conducting multi-fuel furnace combustion and heat transfer studies under pressurized and oxygen-enriched conditions. This device is a 100-kilowatt-level pilot-scale experimental platform, and its furnace body 1 can achieve a thermal power of 50... Adjustable within the range of 200KW, with a working pressure adjustment range of 0. With a pressure of 1.6 MPa, it can directly simulate the local operating conditions of industrial boilers, providing data support for boiler design optimization.

[0032] The entire device includes a furnace body 1, a gas supply system 2, a gas burner 3, a solid material supply system 4, a flue gas treatment system 5, a heat exchange system 6, and a measurement system.

[0033] Furnace body 1 is the core reaction space of the experiment, and a pressurized combustion environment can be formed inside.

[0034] The gas supply system 2 has multiple independent gas sources and pipelines, all connected to the furnace body 1, capable of supplying at least two different gas media to the furnace body 1. These can include combustion gases, such as a mixture of oxygen and carbon dioxide, or air; fuel gases, such as dimethyl ether, natural gas, methane, or propane; and protective gases, such as nitrogen or argon. Through multiple independent gas sources, the device can flexibly select various gas types, especially when using an oxygen-rich configuration (15%). With a 30% gas mixture, it can directly serve oxygen-enriched combustion research in carbon capture and combustion (CCUS) scenarios. It can also enable the supply and switching of different gaseous fuels.

[0035] The gas burner 3 is connected to the furnace body 1 and also to the aforementioned gas supply system 2. It has a dual function: First, during the preheating stage, fuel gas and combustion-supporting gas (generally air, which is inexpensive, but a mixture of oxygen and carbon dioxide can also be used) from the gas supply system 2 are combusted within it, and the resulting heat medium (flue gas) is introduced into the furnace body 1 to heat it. Second, in the non-combustion state, it can serve as a gas channel, directly supplying gaseous media (such as a mixed gas) from the gas supply system 2 into the furnace body 1. This design achieves a unified and smooth transition between the preheating gas source and the operating gas source.

[0036] Solid material supply system 4 is connected to furnace body 1 and is used to supply solid fuels (such as coal particles, pulverized coal) and / or bed materials (such as sand and other inert particles) into furnace body 1. This system has the ability to continuously feed under pressure, which enables the device to conduct not only gaseous fuel experiments, but also solid fuel (especially fluidized bed combustion and pulverized coal combustion) furnace experiments, overcoming the limitation of traditional experimental devices with single fuel compatibility.

[0037] The flue gas treatment system 5 is connected to the outlet of the furnace body 1 and has dual functions: first, it can precisely adjust the back pressure inside the furnace body 1 through the pressure regulating valve 54 at its end to stabilize the pressure inside the furnace at the target pressure (such as 1.5MPa); second, it can purify the discharged flue gas (such as dust removal) to meet environmental emission requirements, and can also perform flue gas sampling and analysis during the process.

[0038] The heat exchange system 6 is connected to the furnace body 1. Its core function is to orderly transfer heat between different areas within the furnace, prevent overheating, and simulate the heating surface of a boiler. It may include multiple heat exchangers 61 arranged within the furnace and multiple heat exchange probes 62 that can be inserted into different areas within the furnace. The heat exchange medium (such as water, air, carbon dioxide, etc.) can circulate within it or flow in a single pass to carry away heat.

[0039] The measurement system is connected to the heat exchange system 6 and is specifically designed to measure heat exchange parameters in different areas of the furnace body 1, such as heat transfer coefficient, tube wall temperature, medium inlet and outlet temperatures, and flow rates. In conjunction with heat exchange probes 62 positioned in typical locations such as the dense phase region, splash region, and dilute phase region, key heat exchange data can be obtained directly under actual combustion conditions, solving the current problem of a lack of practical furnace heat exchange research methods in this field.

[0040] In summary, the device in this embodiment integrates "gas supply" combustion heat exchange Measurement The entire process of flue gas treatment has formed a fully functional and realistic pressurized oxy-fuel combustion experimental platform. It can simulate various combustion states from gaseous fuels to solid fuels and from atmospheric pressure to high pressure. In this process, it can directly measure the heat transfer coefficient of the actual furnace and analyze the combustion characteristics, providing key experimental data and R&D methods for the design of pressurized oxy-fuel combustion boilers.

[0041] In some embodiments, the furnace body 1 includes a furnace chamber 11, an air distribution plate 12, a gas chamber 14, a first air inlet 15, a guide tube 16, and a third air inlet 18. The air distribution plate 12 is disposed at the lower part of the furnace chamber 11 and is provided with a plurality of fluidizing nozzles 13. The gas chamber 14 is located below the air distribution plate 12 and the plurality of fluidizing nozzles 13 are connected to the gas chamber 14. The first air inlet 15 is connected to the gas chamber 14, and the outlet of the gas burner 3 is connected to the first air inlet 15. The guide tube 16 passes through the gas chamber 14 and the air distribution plate 12. The upper end of the guide tube 16 is placed inside the furnace chamber 11, and the lower end of the guide tube 16 forms a second air inlet 17. The third air inlet 18 is located in the middle region of the furnace body 1 and is connected to the furnace chamber 11.

[0042] The furnace 11 of the combustion heat exchange experimental apparatus of this invention is the main space for combustion and heat exchange reactions. An air distribution plate 12 is provided at the lower part of the furnace 11, and multiple fluidizing nozzles 13 are installed on the air distribution plate 12. Below the air distribution plate 12 is a gas chamber 14, which is connected to all the fluidizing nozzles 13, allowing the gas entering the gas chamber 14 to be evenly distributed to the lower part of the furnace 11 through the air distribution plate 12, which is particularly suitable for creating the fluidized state required for fluidized bed combustion.

[0043] To ensure heat retention and operational safety within the furnace, in some specific embodiments, the space between the sidewall of the furnace chamber 11 and the outer shell of the furnace body 1 is filled with high-efficiency insulation material. This design ensures that the temperature of the outer shell of the furnace body 1 does not exceed 50°C under any operating condition. Furthermore, the air chamber 14 is connected to the area containing the insulation material to maintain uniform pressure on the inner and outer sides of the furnace chamber's sidewall. For example, a gap is provided between the air chamber 14 below the air distribution plate 12 and the insulation material inside the furnace body 1. This gap balances the pressure inside the furnace chamber 11 and outside the insulation layer, thus maintaining a pressure balance on the sidewall of the furnace chamber 11 and preventing it from bearing differential pressure loads. This improves the structural safety and reliability of the furnace body 1 during long-term operation under high pressure (e.g., 0-1.6 MPa).

[0044] The first air inlet 15 is connected to the gas chamber 14. The outlet of the gas burner 3 is connected to the first air inlet 15. This means that during the preheating stage, the high-temperature flue gas generated by the gas burner 3 can enter the gas chamber 14 through this path, and then flow into the furnace 11 through the air distribution plate 12 to achieve overall heating of the furnace 11 and the bed material; during the normal operation stage, when the gas burner 3 is used as a channel, the oxygen and carbon dioxide mixture from the gas supply system 2 can also enter through this inlet as a fluidizing medium or combustion-supporting gas.

[0045] The guide tube 16 is a cylindrical structure that runs through the gas chamber 14 and the air distribution plate 12. Its lower end forms a second air inlet 17, while its upper opening is located inside the furnace 11. This design provides an alternative and independent transport path for gaseous fuels or other media, allowing them to be directly injected into a specific height in the furnace 11 without passing through the air distribution plate 12. This facilitates the formation of a localized combustion zone or the separate transport of fuel gases.

[0046] The third air inlet 18 is located in the middle region of the furnace body 1 and is directly connected to the furnace chamber 11. This air inlet is used to directly send a portion of the combustion-supporting gas (such as a mixture of oxygen and carbon dioxide) into the upper part of the furnace chamber 11, which helps to ensure the complete combustion of fuel. Especially for pulverized coal combustion or conditions requiring staged air distribution, it can effectively regulate the temperature field and combustion efficiency inside the furnace.

[0047] To monitor the furnace interior status in real time, multiple detection units 19 are installed along the height of the furnace body 1 to detect the temperature and / or pressure at different locations, providing a basis for precise control and data analysis of the experimental process.

[0048] By setting up an air distribution plate 12, an air chamber 14, a pressure balance gap, three air inlets at different positions, and a detection unit 19 along the furnace height, the furnace body 1 structure in this embodiment not only has strong adaptability to working conditions and supports multiple combustion modes from fluidized bed to pulverized coal combustion, but also focuses on solving key safety issues such as heat loss control and pressure balance in the pressurized experimental device.

[0049] In some embodiments, the plurality of gas supply systems 2 include a first gas supply system 21 and a third gas supply system 23. The first gas supply system 21 is used to provide a mixture of oxygen and carbon dioxide, and the third gas supply system 23 is used to provide a fuel gas, which includes at least one selected from dimethyl ether, natural gas, methane, and propane. The plurality of gas supply systems 2 includes a second gas supply system 22, which is used to provide air. The plurality of gas supply systems 2 includes a fourth gas supply system 24, which is used to provide a protective gas, which is at least one selected from nitrogen, argon, and helium.

[0050] In this embodiment, the multiple independent gas supply systems 2 specifically include a first gas supply system 21 and a third gas supply system 23, and may optionally include a second gas supply system 22 and a fourth gas supply system 24.

[0051] The first gas supply system 21 provides a mixture of oxygen and carbon dioxide, which is the core combustion medium for achieving pressurized oxygen-enriched combustion and carbon capture simulation in this experimental setup. The volume percentage of oxygen in the mixture can be precisely adjusted within the range of 15% to 30% to meet the requirements of the combustion atmosphere under different fuels and operating conditions. Its supply pressure can be increased by a booster device 215 (e.g., a pump) to meet the needs of high-pressure combustion experiments.

[0052] The third gas supply system 23 is used to provide fuel gas. It has a wide range of fuel compatibility and can select at least one of dimethyl ether, natural gas, methane, and propane according to experimental needs, providing a flexible fuel selection scheme for pressurized oxygen-enriched combustion experiments of gaseous fuels.

[0053] An optional second air supply system 22 is used to supply air. This air is mainly used during the preheating stage as a combustion aid for the initial combustion of fuel gas in the gas burner 3, in order to reduce preheating costs and quickly raise the furnace temperature 11 to the required preheating temperature (e.g., 400-800°C). After the initial preheating stage is completed, the system will switch to an oxygen-rich atmosphere, and the air passage will be closed or stopped.

[0054] An optional fourth gas supply system 24 is used to provide a protective gas, which is at least one of nitrogen, argon, and helium, with nitrogen being the most commonly used. This protective gas system has a safety protection function and can be introduced into the furnace body 1 or gas burner 3 in emergency situations (such as unstable combustion or the need for emergency shutdown) to achieve rapid fire extinguishing or safe purging of pipelines, ensuring the safety of the experimental process.

[0055] By configuring the aforementioned multiple independent and functionally defined gas supply systems 2, this embodiment constructs a gas supply network for the combustion heat exchange experimental device that is comprehensive in its gas source types, fully functional, and flexibly controllable. It not only accurately provides the main and auxiliary combustion gases (a mixture of oxygen and carbon dioxide) and various fuel gases required for oxygen-enriched combustion, but also addresses the practical needs of system preheating and startup while ensuring reliable safe operation. This enables the device to safely, stably, and flexibly conduct various complex combustion experiments under conditions ranging from gas to solid and from atmospheric pressure to high pressure.

[0056] In some embodiments, the first gas supply system 21 includes an oxygen supply device 211, a carbon dioxide supply device 212, a premixing tank 213, a mixed gas storage tank 214, and a pressurizing device 215. The oxygen supply device 211 and the carbon dioxide supply device 212 are used to supply oxygen and carbon dioxide, respectively. The oxygen supply device 211 and the carbon dioxide supply device 212 are connected to the premixing tank 213 so that oxygen and carbon dioxide enter the premixing tank 213 for premixing. The premixing tank 213 is connected to the mixed gas storage tank 214 for storing the mixed gas. The pressurizing device 215 is disposed between the premixing tank 213 and the mixed gas storage tank 214 for making the pressure of the mixed gas in the mixed gas storage tank 214 reach a target value.

[0057] In some specific embodiments, the output of the mixed gas storage tank 214 is divided into two paths via pipelines: one path is connected to the third air inlet 18 in the middle region of the furnace body 1; the other path is connected to the gas burner 3. This connection method allows the premixed and pressurized oxygen and carbon dioxide mixture to have two optional delivery paths: it can be directly injected into the middle of the furnace 11 as a combustion-supporting gas to participate in the combustion chemical reaction in the main combustion zone; it can also be used as a preheating and combustion-supporting gas for the gas burner 3, and then burned through the gas burner 3, or the gas burner 3 can be used as a channel to enter the furnace 11. This dual-path design provides flexibility for experimental condition control. For example, during solid fuel fluidized bed combustion, one path of the mixed gas can enter the furnace 11 through the gas burner 3 to achieve solid fuel fluidization, while the other path can enter from the middle air inlet to ensure complete combustion.

[0058] In some specific embodiments, the output of the third gas supply system 23 is also divided into two paths via pipelines: one path is connected to the second air inlet 17 at the bottom of the furnace body 1 (i.e., the lower end of the guide tube 16); the other path is also connected to the gas burner 3. This allows the fuel gas (such as methane, propane, etc.) to have two supply modes: one path can be directly injected into the furnace 11 to participate in combustion; the other path can be delivered to the gas burner 3 for combustion and heat generation during the preheating stage. Especially when switching from the gas burner 3 mode to the furnace body 1 combustion mode, the fuel gas can be switched to the second air inlet 17 to directly enter the furnace 11. At the same time, when the gas burner 3 lacks fuel gas, it will be extinguished, thus serving as a channel for the mixed gas to pass through.

[0059] This embodiment, through the dual-pipeline connection design of the first gas supply system 21 and the third gas supply system 23, provides an implementation scheme for the "gradual transition" operation in subsequent experimental methods. For example, after preheating, by adjusting the valve, the fuel gas flow rate to the gas burner 3 can be gradually reduced, while the fuel gas flow rate to the second air inlet 17 of the furnace body 1 can be increased, until the fuel gas is completely switched to direct combustion in the furnace, thereby achieving a stable transition from external preheating to autonomous combustion in the furnace. This gas path design simplifies the operation process, avoids large fluctuations in pressure and flame during operating condition switching, and ensures the continuity of the experimental process and the stability of measurement data.

[0060] In some embodiments, the solid material supply system 4 includes a receiving device 41, a pressurizing chamber 42, and a feeder 43. The receiving device 41 is used to receive solid fuel and / or bed material. The pressurizing chamber 42 is connected to the receiving device 41 to receive and pressurize the solid fuel and / or bed material from the receiving device 41. The feeder 43 is connected to the pressurizing chamber 42 and the furnace body 1 to transport the solid fuel and bed material to the furnace chamber 11.

[0061] In this embodiment, the receiving device 41 is the starting end of the system, used to receive and temporarily store external solid fuels (such as coal particles or coal powder of different sizes) and / or bed materials (such as inert particles such as quartz sand) to provide material preparation for experiments.

[0062] The pressurization chamber 42 is connected to the receiving device 41 and is used to receive materials from the receiving device 41 and pressurize them. This is to achieve a continuous and stable supply of solid materials under high-pressure experimental conditions.

[0063] In some specific embodiments, the pressurization chamber 42 comprises two independent pressure vessels connected in series, with the two pressurization chambers 42 connected by a conveying pipe equipped with valves. During operation, the two pressurization chambers 42 alternately cycle through "pressurization-conveyance-depressurization-loading": while one chamber is pressurizing and conveying material into the furnace, the other chamber can be connected to the receiving device 41 to receive the next batch of material at atmospheric or lower pressure and prepare for sealing. This dual-chamber series-connected, alternating operation design cleverly solves the problem of continuously and stably adding solid materials from an atmospheric pressure environment to the high-pressure furnace 11, avoiding frequent fluctuations in furnace pressure or interruptions in material supply caused by feeding in single-chamber mode, and ensuring the continuity of operation in combustion experiments, especially fluidized bed combustion experiments that require long-term stable operation.

[0064] The feeder 43 is connected to the pressurization chamber 42 and the furnace body 1, and it precisely and controllably delivers solid fuel or bed material from the pressurization chamber 42 into the furnace chamber 11. Specifically, the feeder 43 can be a screw conveyor, and the outlet of the feeder 43 is connected to the furnace chamber 11 through a dedicated particulate material inlet. This particulate material inlet can be cylindrical and sealed to the furnace chamber 11 to ensure that solid particles can smoothly enter the high-pressure furnace chamber 11.

[0065] The solid material supply system 4 in this embodiment, especially the series design of the dual pressurized chambers 42 and the dedicated particulate material connection port, provides key technical support for combustion experiments of coal particles (fluidized bed) and pulverized coal under high pressure of 0-1.6MPa. It enables the experimental device to simulate the actual working conditions of continuous coal feeding in industrial boilers, overcoming the technical bottleneck that small-scale laboratory devices cannot achieve high-pressure continuous solid feeding.

[0066] In some embodiments, the flue gas treatment system 5 includes, in sequence along the flue gas flow direction, a cyclone separator 51, a heat exchange assembly 52, a dust collector 53, and a pressure regulating valve 54, wherein the bottom of the cyclone separator 51 is provided with an ash tank 55, and the pressure regulating valve 54 is used to regulate the back pressure of the furnace body 1.

[0067] In the combustion heat exchange experimental apparatus of this invention, the cyclone separator 51 serves as the first stage of flue gas purification and is located at the very front of the system. It utilizes centrifugal force to efficiently separate and capture larger particulate matter (such as unburned fuel particles, bed material, or large fly ash particles) carried in the flue gas. An ash container 55 is connected to the bottom of the cyclone separator 51 to collect the separated solid particles. An ash discharge port is located below the ash container 55, which serves the dual function of periodically discharging accumulated ash and taking samples for analysis during the experiment, facilitating the analysis of the collected particles' composition and morphology.

[0068] The heat exchange component 52 is located after the cyclone separator 51. Its main function is to cool the high-temperature flue gas, reduce the workload of subsequent dust removal equipment, and recover some of the waste heat from the flue gas.

[0069] In some specific embodiments, a flue gas sampling port 56 is provided on the pipeline after the heat exchange component 52 and before the dust collector 53. This sampling port is used to collect representative flue gas samples before deep purification of the flue gas, and send them to a gas analyzer for real-time online analysis or offline testing of components (such as O2, CO2, CO, NO combustion heat exchange experimental device, etc.). It is a key monitoring point for evaluating combustion efficiency and pollutant generation characteristics.

[0070] The dust collector 53 is located after the heat exchange assembly 52 and typically employs high-efficiency filtration or electrostatic precipitators to remove fine dust from the flue gas, ensuring that the emitted flue gas meets environmental protection requirements. Similarly, a discharge port is provided below the dust collector 53 to discharge the captured fine ash, which can then be sampled and analyzed to study the ash's characteristics.

[0071] The pressure regulating valve 54 is located at the end of the entire flue gas treatment system 5. Its core function is to precisely regulate and control the resistance at the system outlet, thereby indirectly and effectively controlling the back pressure inside the furnace 1. By adjusting the opening of this valve, the pressure inside the furnace 11 can be stabilized at a preset target pressure value, such as any value within the range of 0-1.6 MPa.

[0072] The flue gas treatment system 5 in this embodiment not only purifies the experimental flue gas but also achieves precise control of the furnace working pressure through the pressure regulating valve 54. It collects and samples solid products through the cyclone separator 51, dust collector 53, and matching ash hopper 55 and ash discharge port, and monitors gaseous products through a dedicated flue gas sampling port 56. This system provides stable and controllable outlet boundary conditions for pressurized oxygen-enriched combustion experiments and constructs a complete combustion product (gas and solid) analysis chain, making it an indispensable component for obtaining comprehensive experimental data and evaluating combustion and environmental performance.

[0073] In some embodiments, the heat exchange system 6 includes: a plurality of heat exchangers 61 and a plurality of heat exchange probes 62. The heat exchangers 61 are placed inside the furnace body 1. The heat exchange probes 62 are connected to the measurement system. The heat exchange probes 62 are disposed in the dense phase region, splash region, dilute phase region and flue gas outlet region of the furnace body 1. The heat exchange probes 62 have a U-shaped tube structure and thermocouples for measuring the tube wall temperature are disposed on their tube walls.

[0074] In some embodiments, the heat exchange system 6 further includes a cooler 63, and a plurality of heat exchangers 61 and a plurality of heat exchange probes 62 are connected to the cooler 63 via pipes so that the heat exchange medium in the cooler 63 flows between the cooler 63, the heat exchangers 61 and the heat exchange probes 62.

[0075] This embodiment further specifies the heat exchange system 6 and its cooling circulation loop of the combustion heat exchange experimental device. The heat exchange system 6 is the core functional module that enables direct measurement of the heat exchange performance of different areas inside the furnace under real combustion conditions.

[0076] The heat exchange system 6 includes multiple heat exchangers 61 placed inside the furnace body 1, multiple heat exchange probes 62 connected to a measurement system (e.g., a control system or a computer system), and a cooler 63 for supplying and circulating the heat exchange medium.

[0077] The heat exchanger 61 is directly arranged in different areas inside the furnace 11, such as near the dense phase area above the air distribution plate 12 and the dilute phase area at the top of the furnace 11. Its function is to actively absorb and transfer heat during combustion, simulate the actual working state of the heating surface of an industrial boiler, and at the same time help maintain the stability of the furnace 11 temperature and prevent local overheating.

[0078] Heat transfer probes 62 are key sensors used to directly measure local heat transfer parameters. They are specifically positioned in representative areas within the furnace 11, including the dense phase zone, splash zone, dilute phase zone, and flue gas outlet zone. Each heat transfer probe 62 has a U-shaped tube structure, consisting of an inlet pipe and an outlet pipe, which are made of high-temperature resistant metal tubes to withstand the high-temperature environment inside the furnace. Multiple thermocouple mounting slots are machined into the metal tube wall of the probe for precise installation of thermocouples, thereby directly measuring the tube wall temperature at that location. The inlet and outlet pipes are arranged symmetrically, and the thermocouples are installed at symmetrical positions to obtain more comprehensive wall temperature distribution data. By measuring the tube wall temperature (Ti), the temperature of the heat transfer medium before entering the probe (Tin), and the temperature after exiting the probe (Tout), combined with parameters such as the medium flow rate, the heat transfer coefficient at that local location can be calculated using heat transfer formulas. The measurable or calculateable heat transfer parameters include, but are not limited to, the heat transfer coefficient, tube wall temperature, heat transfer medium inlet temperature, outlet temperature, and flow rate.

[0079] Cooler 63, heat exchanger 61, and heat exchange probe 62 are interconnected via a piping network, forming a complete closed-loop circulation circuit. The heat exchange medium (e.g., at least one of water, air, carbon dioxide, or nitrogen) within cooler 63 circulates within this circuit under the drive of a pump. The flow pattern can be designed as either circulating cooling or single-pass non-circulating cooling, depending on experimental requirements. The medium flows through heat exchanger 61 and each heat exchange probe 62 within the furnace, absorbs heat, and is then transported back to cooler 63 for cooling. After releasing heat, it re-enters the circulation circuit. This design ensures the controllability and stability of the heat exchange medium temperature during long-term experiments, thereby ensuring the accuracy of the measurement data.

[0080] Furthermore, the flow rates of the heat exchange medium in multiple heat exchangers 61 and multiple heat exchange probes 62 can be adjusted independently. This feature allows researchers to independently control the cooling intensity flowing through each heat exchange surface or probe according to the different heat flux densities and measurement requirements of each region, thereby more accurately simulating the different working conditions of the heating surfaces in an actual boiler and obtaining more realistic and reliable local heat transfer characteristic data.

[0081] The heat exchange system 6 in this embodiment organically combines an active heat exchanger 61, a multi-zone heat exchange probe 62 dedicated to fine measurement, and an adjustable medium circulation loop. This constructs an experimental platform capable of directly and in-situ measuring the heat transfer coefficients of key areas such as the dense phase zone and splash zone under pressurized oxy-fuel combustion furnace conditions. It overcomes the limitations of traditional "hot bed cold tube" or "heat tube cold bed" simulation methods, providing crucial measured data for overcoming the core technical challenge of arranging heating surfaces and orderly heat transfer within the confined space of a pressurized oxy-fuel combustion boiler.

[0082] The following describes a combustion heat transfer experimental method according to an embodiment of the present invention. The combustion heat transfer experimental method is implemented using the combustion heat transfer experimental apparatus described in any of the above embodiments, including: Preheating step: Fuel gas and air are supplied to the gas burner 3 through two gas supply systems 2 respectively, so that the fuel gas and air can burn in the gas burner 3 and preheat the furnace body 1 until the furnace body 1 reaches the preheating temperature, and then the gas supply system 2 stops supplying fuel gas to the gas burner 3. Gas combustion steps: fuel gas is supplied into the furnace body 1 through the gas supply system 2, the air supply is gradually stopped, and a mixture of oxygen and carbon dioxide is supplied into the furnace body 1 through the gas burner 3 via the gas supply system 2, so that the fuel gas and the mixture can burn stably in the furnace body 1. Solid combustion steps: The fuel gas supplied to the furnace body 1 is gradually reduced through the gas supply system 2, and solid fuel is supplied to the furnace body 1 through the solid material supply system 4, so that the solid fuel and the mixed gas can burn stably in the furnace body 1. Parameter measurement steps: Under stable combustion conditions in the gas combustion or solid combustion steps, the heat transfer parameters of different areas inside furnace body 1 are measured by the measurement system; In the gas combustion and solid combustion steps, the back pressure of the furnace body 1 is adjusted by the flue gas treatment system 5 to maintain the internal pressure of the furnace body 1 at the target pressure and ensure stable combustion; and, When the solid fuel is coal pellets, a preparatory step is included before the preheating step: bed material is introduced into the furnace body 1 through the solid material supply system 4.

[0083] Specifically as follows: Preparatory steps (optional): When the experimental objective is pressurized oxygen-enriched combustion of a coal-fired fluidized bed, before the preheating begins, a certain amount of inert bed material needs to be introduced into the furnace body 1 through the solid material supply system 4 and laid on the air distribution plate 12 to prepare for the subsequent formation of the fluidized bed.

[0084] Preheating Step: Upon starting the device, fuel gas and air are supplied to the gas burner 3 via two independent gas supply systems 2 (third gas supply system 23 and second gas supply system 22). The fuel gas and air burn within the gas burner 3, and the resulting high-temperature flue gas is introduced into the furnace body 1, heating the furnace body 1 and the bed material (if already added) as a whole. This continues until the furnace body 1 reaches a preheating temperature suitable for subsequent combustion. The preheating temperature must be higher than the ignition point of the fuel used to ensure rapid ignition during the combustion process. The preheating temperature is determined based on the type of fuel used: 400-800℃ when using fuel gas; 400-800℃ when using coal pellets; and 500-800℃ when using pulverized coal. At this point, the supply of fuel gas to the gas burner 3 can be stopped, while the air supply can continue, allowing the fuel gas to initially burn within the furnace body with the aid of air during the subsequent gas combustion process.

[0085] In addition, the proportion of air can be appropriately increased in the preset steps. Since the temperature of the heat medium (flue gas) generated by fuel gas and air is 800-100 degrees Celsius, in order to reduce the temperature that the gas burner can withstand, the proportion of air can be increased at an appropriate time to reduce the temperature of the heat medium.

[0086] Gas combustion step: After the furnace body 1 temperature stabilizes at the preheating temperature, the supply of fuel gas and mixed gas to the furnace body is initiated. Specifically, the fuel gas supply path is shifted from the gas burner 3 to the furnace body 1 by adjusting the valve. Preferably, the fuel gas is divided into two paths: one to the gas burner 3 and the other to the second air inlet 17 at the bottom of the furnace body 1. During operation, the fuel gas flow rate to the gas burner 3 can be gradually reduced while the fuel gas flow rate to the interior of the furnace body 1 is increased until all the fuel gas is supplied through the second air inlet 17 at the bottom of the furnace body 1, achieving a slow transition from the preheating step to the gas combustion step. Alternatively, the supply to the gas burner 3 can be directly shut off, while the supply to the second air inlet 17 can be opened. When fuel gas is only supplied to the furnace body, the air supply can be maintained initially to allow for rapid ignition of the fuel gas, followed by a gradual reduction in the air supply, or the air supply can be directly shut off.

[0087] Simultaneously, the mixture of oxygen and carbon dioxide can enter the furnace 11 through the first inlet 15 via the gas burner 3 (which serves only as a channel in this case). The mixed gas entering the furnace through the gas burner 3 can be evenly distributed or used to fluidize the bed material (if any). The fuel gas and the mixed gas mix and burn stably within the furnace 11, completing the transition from external preheating to autonomous combustion within the furnace. In this step, the mixed gas can also be divided into two parts: one part continues to enter through the first inlet 15 (to maintain fluidization or aid combustion at the bottom), and the other part is fed in through the third inlet 18 in the middle of the furnace body 1 to ensure complete combustion of the fuel gas.

[0088] Solid combustion step (applicable to solid fuel experiments): Based on the stable combustion established in the gas combustion step, solid fuel (such as coal particles or pulverized coal) is supplied to the furnace body 1 through the solid material supply system 4. Simultaneously, the fuel gas supplied to the furnace body 1 is gradually reduced through the corresponding gas supply system 2. During this process, the feed rate of the solid fuel, the supply amount of the mixed gas, and the air distribution need to be precisely adjusted to ensure stable combustion of the solid fuel and mixed gas within the furnace body 1, ultimately completely replacing the gaseous fuel. Throughout both the gas combustion and solid combustion steps, the back pressure of the furnace body 1 needs to be adjusted through the pressure regulating valve 54 at the end of the flue gas treatment system 5. The supply amounts of mixed gas, fuel gas, and solid fuel can also be adjusted as needed to precisely maintain the internal pressure of the furnace body 1 within the target pressure range (e.g., 0-1.6 MPa, typically 1.5 MPa) and maintain a stable combustion state.

[0089] Parameter measurement steps: After the gas combustion step or solid combustion step reaches a stable combustion state, data is acquired through the measurement system. Specifically, this includes: recording the tube wall temperature, inlet and outlet temperatures and flow rates of the heat exchange medium at each heat exchange probe 62 arranged in the dense phase zone, splash zone, dilute phase zone and flue gas outlet zone inside the furnace, and calculating the local heat transfer coefficient of each zone; recording the temperature and pressure distribution inside the furnace through the detection units 19 arranged along the furnace height; collecting flue gas through the flue gas sampling port 56 and performing component analysis; and collecting solid products through the ash discharge ports of the ash hopper 55 and dust collector 53 for sampling and testing.

[0090] The key parameters include the following control ranges: the volume percentage of oxygen in the mixed gas is 15% to 30%, and the system working pressure (target pressure) adjustment range is 0-1.6 MPa.

[0091] The experimental method described in this embodiment fully utilizes the experimental apparatus's features of independent multi-source gas supply, multiple air inlets, continuous pressurized feeding, and adjustable back pressure. This enables a complete and controllable experimental process, from system preheating and stable combustion of gaseous fuels to seamless switching to solid fuels. Specifically designed for pressurized oxy-fuel combustion, this method can safely and effectively acquire combustion characteristic data and key local heat transfer coefficients of various fuels, from gaseous to solid, in a simulated industrial furnace environment. It provides a systematic experimental research method for overcoming the challenges of optimizing the heat transfer surface arrangement and design of pressurized oxy-fuel combustion boilers.

[0092] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0093] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0094] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0095] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0096] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0097] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of the present invention.

Claims

1. A combustion heat transfer experimental apparatus, characterized in that, include: Furnace body (1); Multiple independent gas supply systems (2) are connected to the furnace body (1) to supply at least different gas media into the furnace body (1); A gas burner (3) is connected to the furnace body (1), and a gas supply system (2) is connected to the gas burner (3). The gas burner (3) can serve as a channel to supply the gas medium in the gas supply system (2) into the furnace body (1), or the gas medium in the gas supply system (2) can enter the gas burner (3) for combustion, and the heat medium generated by combustion enters the furnace body (1) to heat the furnace body (1). Solid material supply system (4), which is connected to the furnace body (1) and is used to supply solid fuel and / or bed material to the furnace body (1); Flue gas treatment system (5), the flue gas treatment system (5) is connected to the furnace body (1) and is used to adjust the back pressure of the furnace body (1) and purify the flue gas discharged from the furnace body (1); A heat exchange system (6) is connected to the furnace body (1) and is used to transfer heat from different areas within the furnace body (1). A measurement system is connected to the heat exchange system (6) and is used to measure the heat exchange parameters of different areas inside the furnace body (1).

2. The combustion heat transfer experimental apparatus according to claim 1, characterized in that, The furnace body (1) includes: Furnace (11); Air distribution plate (12), the air distribution plate (12) is located at the lower part of the furnace (11), and the air distribution plate (12) is provided with multiple fluidizing nozzles (13). An air chamber (14) is located below the air distribution plate (12), and a plurality of fluidizing nozzles (13) are connected to the air chamber (14); The first air inlet (15) is connected to the air chamber (14), and the outlet of the gas burner (3) is connected to the first air inlet (15). A guide tube (16) is provided, which passes through the gas chamber (14) and the air distribution plate (12). The upper end of the guide tube (16) is placed inside the furnace (11), and the lower end of the guide tube (16) forms a second air inlet (17). The third air inlet (18) is located in the middle region of the furnace body (1) and is connected to the furnace chamber (11).

3. The combustion heat transfer experimental apparatus according to claim 2, characterized in that, The plurality of gas supply systems (2) include: A first gas supply system (21) is used to provide a mixture of oxygen and carbon dioxide; and A third gas supply system (23) is used to supply fuel gas, the fuel gas including at least one of dimethyl ether, natural gas, methane, and propane; and / or A second gas supply system (22) is used to supply air; and / or A fourth gas supply system (24) is used to provide a protective gas, which is at least one of nitrogen, argon and helium.

4. The combustion heat transfer experimental apparatus according to claim 3, characterized in that, The first gas supply system (21) includes: An oxygen supply device (211) and a carbon dioxide supply device (212) are used to provide oxygen and carbon dioxide, respectively; A premixing tank (213) is provided, wherein the oxygen supply device (211) and the carbon dioxide supply device (212) are connected to the premixing tank (213) to allow the oxygen and the carbon dioxide to enter the premixing tank (213) for premixing; A mixed gas storage tank (214) is connected to the premixed tank (213) and the mixed gas storage tank (214) for storing mixed gas; A pressurizing device (215) is provided between the premix tank (213) and the mixed gas storage tank (214) to make the pressure of the mixed gas in the mixed gas storage tank (214) reach the target value.

5. The combustion heat transfer experimental apparatus according to claim 4, characterized in that, The output of the mixed gas storage tank (214) is divided into two paths and connected to the third air inlet (18) and the gas burner (3) respectively; and / or The third gas supply system (23) is divided into two paths and is connected to the second air inlet (17) and the gas burner (3) respectively.

6. The combustion heat transfer experimental apparatus according to claim 2, characterized in that, The solid material supply system (4) includes: A receiving device (41) for receiving the solid fuel and / or the bed material; A pressurization chamber (42) is connected to the receiving device (41) to receive and pressurize solid fuel and / or the bed material from the receiving device (41); The feeder (43) is connected to the pressurized chamber (42) and the furnace body (1) and is used to transport the solid fuel and the bed material to the furnace chamber (11).

7. The combustion heat transfer experimental apparatus according to claim 1, characterized in that, The flue gas treatment system (5) includes, in sequence along the flue gas flow direction, a cyclone separator (51), a heat exchange assembly (52), a dust collector (53), and a pressure regulating valve (54), wherein the bottom of the cyclone separator (51) is provided with an ash tank (55), and the pressure regulating valve (54) is used to regulate the back pressure of the furnace body (1).

8. The combustion heat transfer experimental apparatus according to claim 1, characterized in that, The heat exchange system (6) includes: Multiple heat exchangers (61) are placed inside the furnace body (1); Multiple heat exchange probes (62) are connected to the measurement system. The heat exchange probes (62) are located in the dense phase zone, splash zone, dilute phase zone and flue gas outlet zone of the furnace body (1). The heat exchange probes (62) are U-shaped tube structures, and thermocouples for measuring the tube wall temperature are provided on their tube walls.

9. The combustion heat transfer experimental apparatus according to claim 8, characterized in that, The heat exchange system (6) further includes a cooler (63), and a plurality of the heat exchangers (61) and a plurality of the heat exchange probes (62) are connected to the cooler (63) through pipes so that the heat exchange medium in the cooler (63) flows between the cooler (63), the heat exchangers (61) and the heat exchange probes (62).

10. A combustion heat transfer experimental method, characterized in that, The combustion heat transfer experimental apparatus according to any one of claims 3-9 is used, comprising: Preheating step: fuel gas and air are supplied to the gas burner (3) by the two gas supply systems (2) respectively, so that the fuel gas and air are burned in the gas burner (3) and the furnace body (1) is preheated until the furnace body (1) reaches the preheating temperature, and then the gas supply system (2) stops supplying the fuel gas to the gas burner (3); Gas combustion steps: The fuel gas is supplied to the furnace body (1) through the gas supply system (2), the air supply is gradually stopped, and the mixture of oxygen and carbon dioxide is supplied to the furnace body (1) through the gas burner (3) through the gas supply system (2) so that the fuel gas and the mixture are stably burned in the furnace body (1); Solid combustion step: The fuel gas supplied to the furnace body (1) is gradually reduced by the gas supply system (2), and solid fuel is supplied to the furnace body (1) by the solid material supply system (4) so ​​that the solid fuel and the mixed gas burn stably in the furnace body (1); Parameter measurement steps: Under the stable combustion state of the gas combustion step or the solid combustion step, the heat exchange parameters of different areas in the furnace body (1) are measured by the measurement system; In the gas combustion step and the solid combustion step, the back pressure of the furnace body (1) is adjusted by the flue gas treatment system (5) so that the furnace body (1) is maintained at the target pressure and combustion is stable. When the solid fuel is coal particles, a preparatory step is included before the preheating step: the bed material is introduced into the furnace body (1) through the solid material supply system (4).

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