Test system of activated ammonia gas burner

Abstract

The invention belongs to the technical field of combustor testing, discloses a testing system of an activated ammonia gas combustor, and aims to solve the problems that a traditional system is insufficient in real-time monitoring and quantification of key parameters in the activated ammonia gas combustion process, a coupling mechanism of activation parameters, a flow field and chemical reaction kinetics is difficult to reveal, and performance improvement is hindered. The system is characterized by comprising a fuel air supply control unit, an activation module, a combustor test cavity, an optical diagnosis system, a thermodynamic monitoring unit, an exhaust analysis pollutant monitoring unit and a data acquisition and processing control system. By the adoption of the technical scheme, comprehensive, real-time and high-precision monitoring of key parameters in the whole combustion process can be achieved, complex coupling of activation parameters and a combustion mechanism is revealed, and accurate guidance is provided for optimization.

Description

Technical Field

[0001] This invention belongs to the field of burner testing technology, and more specifically, relates to a testing system for activated ammonia burners. Background Technology

[0002] The combustion characteristics of pure ammonia present inherent challenges, including a low flame propagation speed, high ignition energy requirements, a narrow ignition limit, and a tendency to produce nitrogen oxides (NOx) at high temperatures. These factors significantly limit its efficiency and environmental friendliness in large-scale direct application as a fuel. To overcome these bottlenecks, research and engineering fields have been continuously exploring various "activated ammonia combustion" technologies. These technologies aim to effectively improve the combustion activity and stability of ammonia through pre-pyrolysis, hydrogen doping, plasma enhancement, or optimization of burner structure, while simultaneously achieving effective NOx control, thereby enabling ammonia to replace fossil fuels more efficiently and cleanly.

[0003] Existing testing systems typically include fuel and air supply metering units, combustion chambers, exhaust gas analyzers, and basic temperature and pressure sensors. These systems allow engineers to gain a preliminary understanding of the burner's overall operating characteristics under specific conditions and to make initial adjustments and optimizations to burner design parameters such as fuel injection methods, swirler angles, and mixing section lengths. These systems are fundamentally based on "black box" measurement and analysis of the combustion process, focusing on the macroscopic correlation between input and output, and providing interim performance feedback in offline or semi-online modes.

[0004] However, with the in-depth development of activated ammonia combustion technology and the imposition of more stringent requirements on its performance indicators, some inherent characteristics of the aforementioned traditional testing schemes at the principle level have gradually revealed their deep-seated limitations in addressing new challenges. Traditional testing systems typically struggle to monitor and quantify key intermediate parameters of the activation process in real time and with precision, and are even less able to reveal the dynamic coupling mechanism between these activation parameters and the complex flow field inside the burner (such as turbulent mixing intensity and recirculation zone characteristics) and the kinetics of combustion chemical reactions.

[0005] Therefore, how to construct a testing system that can comprehensively, in real time, and with high precision monitor and analyze the key parameters of the entire chain of activated ammonia combustion, from fuel activation, transport and mixing to final combustion and pollutant generation, and effectively reveal the complex coupling mechanism between each link, has become a key technical problem that urgently needs to be solved in the current research and development of activated ammonia burners. This is of great significance for accelerating the industrialization process of clean and efficient ammonia fuel technology. Summary of the Invention

[0006] To address the aforementioned issues, this invention proposes a testing system for activated ammonia burners. The aim is to effectively reveal the complex coupling mechanisms between various components, thereby providing a solid technical foundation for the design, development, and performance optimization of activated ammonia burners.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A test system for activating an ammonia burner includes: The burner test chamber is used to install the activated ammonia burner to be tested and to provide a controlled combustion environment; An activation module, located outside the burner test chamber, is used to pre-activate the ammonia fuel. The gas supply unit, whose output is connected to the activation module or the burner test chamber, is used to accurately measure, mix and deliver ammonia fuel and oxidant. An optical diagnostic system is installed at the corresponding window on the outside of the burner test chamber to non-invasively monitor the flow field, temperature field, component field and flame morphology inside the burner. Thermodynamic monitoring unit includes sensors installed inside the burner test chamber to acquire real-time temperature and pressure information of the burner interior and surrounding environment; The exhaust monitoring unit, with its sensors positioned at the top exhaust port of the burner test chamber, is used for quantitative analysis of pollutant components in the combustion products; and The control system is electrically connected to the gas supply unit, activation module, optical diagnostic system, thermodynamic monitoring unit, and exhaust monitoring unit. It is used to integrate, synchronize, and analyze data from all sensors and diagnostic devices, and to precisely control the entire testing process.

[0008] Preferably, the gas supply unit includes multiple high-precision mass flow controllers, multiple pressure regulating valves, a gas mixer, and a fuel preheater. The high-precision mass flow controller is installed in the gas input pipeline to independently control the mass flow rates of ammonia, hydrogen, air, and optional oxygen. The pressure regulating valve is installed in the pipeline between the gas mixer and the activation module or the burner test chamber, and is used to stabilize the pressure of each gas at a preset value. The gas mixer is located at the end of the gas input pipeline and has a static mixing structure or a vortex dynamic mixing chamber to ensure that multiple gases are uniformly mixed before entering the activation module or the burner test chamber. The fuel preheater is an electric heating preheater, which integrates a temperature sensor and a PID controller.

[0009] Preferably, the activation module is configured to be interchangeable or combined depending on the activation method, and includes at least one catalytic pre-pyrolysis unit or one plasma activation unit.

[0010] Preferably, the catalytic pre-cracking unit includes a tubular or plate reactor. The main material of the catalytic pre-cracking unit is quartz glass or Inconel 625 high-temperature alloy. The interior is filled with a noble metal-based catalyst, which is supported on a high specific surface area carrier. The reactor is wrapped with electric heating wires and insulation materials, and multi-point thermocouples are integrated to monitor the temperature distribution inside the reactor. The catalytic pre-pyrolysis unit is equipped with an online gas sampling port, which uses a heated sampling probe. The heated sampling probe is connected to a gas chromatograph or a tunable semiconductor laser absorption spectroscopy system via a heated pipeline to analyze in real time the molar ratio of ammonia, hydrogen and nitrogen and other intermediate product components in the pre-pyrolysis products. The gas chromatograph is equipped with a thermal conductivity detector or a flame ionization detector.

[0011] Preferably, the plasma activation unit includes a dielectric barrier discharge plasma generator or a microwave plasma generator, wherein the electrode material is stainless steel or alumina ceramic, and the dielectric material is high-purity quartz or alumina ceramic. The generator is powered by a high-frequency high-voltage power supply or a microwave power supply. The generator is also equipped with a high-voltage probe and a current probe to measure the voltage and current waveforms of plasma discharge and to calculate the plasma dissipation power by the Lissajous figure method or the direct integration method. An optical window is provided at the outlet of the plasma generator. The plasma generator is connected to a fiber optic spectrometer for emission spectral diagnosis to identify and quantify the active free radicals present in the plasma and their relative concentrations.

[0012] Preferably, the burner test chamber is a double-layer water-cooled or air-cooled stainless steel structure, lined with high-temperature resistant ceramic material to ensure that the temperature of the chamber wall is controllable and the test environment is stable. The cavity wall is symmetrically provided with at least four sets of optical access windows along the optical path direction. These windows are made of high-purity synthetic quartz or sapphire, with an optical transmittance of more than 95% in the ultraviolet to near-infrared band. They are also designed in a conical shape and integrated with a purge gas interface to reduce wall effect and optical distortion. The cavity is designed with an adjustable burner mounting flange, which allows for fine adjustment of the burner in three dimensions and three angles. The cavity is equipped with a multi-channel pressure sensor on the top or side. The pressure sensor is piezoelectric or strain gauge designed to capture combustion instability events.

[0013] Preferably, the burner mounting flange includes a flange, three linear motion pairs, a sleeve, a ventilation pipe, three folding arms, multiple locking screws, a sleeve clamp, and a composite corrugated cover. The flange is installed at the end of the activation module and is used to seal the internal cavity of the activation module. The three linear motion pairs are installed on the flange end face. Each linear motion pair has a linear motion terminal and serves as a power device for adjusting the position and angle of the burner. One end of each of the three folding arms is hinged to the linear motion terminal of each of the three linear motion pairs, and the other end of each of the three folding arms is hinged to the outer periphery of the sleeve clamp, thereby forming a support for the sleeve clamp and a transmission component. The locking screw is installed at the connection of the branch folding arm of the folding arm, and is used to pre-adjust the folding angle of the folding arm according to preset parameters, and to limit the maximum operating range of the burner; Sleeve clamps are used to install burners and to stably hold them in place; The sleeve is installed between the activation module and the burner test chamber; The composite corrugated cover seals the opening at the end of the sleeve, and together with the sleeve, forms a heat-insulating cavity between the activation module and the burner test chamber; The ventilation pipeline is installed in the sleeve to reduce the temperature of the insulation cavity through active ventilation and to prevent gas from entering the insulation cavity and causing deflagration. The flange has a through hole for the gas supply pipe that supplies gas to the burner to pass through.

[0014] Preferably, the optical diagnostic system includes: a particle image velocimetry system, a coherent anti-Stokes Raman scattering system or a tunable semiconductor laser absorption spectroscopy temperature measurement system, a planar laser-induced fluorescence system, a Raman scattering system, and a high-speed flame imaging system.

[0015] Preferably, the particle image velocimetry system includes a dual-pulse Nd:YAG laser, a high-resolution sCMOS camera, and a synchronization controller. The dual-pulse Nd:YAG laser provides a single-pulse laser output with an energy of not less than 150 millijoules at a wavelength of 532 nanometers, a pulse width of less than 8 nanoseconds, and a pulse interval that is continuously adjustable from 0.5 microseconds to 1 millisecond, for illuminating alumina or silica tracer particles with a particle size of 1 to 5 micrometers. The high-resolution sCMOS camera has an image resolution of not less than 2560x2160 pixels and a full-frame acquisition rate of not less than 15 Hz. The sCMOS camera is equipped with corresponding optical filters and objectives, and obtains the transient two-dimensional velocity vector field inside the burner through cross-correlation calculation. The coherent anti-Stokes Raman scattering system or tunable semiconductor laser absorption spectroscopy temperature measurement system is used to accurately measure the transient temperature field inside the burner.

[0016] Preferably, the planar laser-induced fluorescence system includes a tunable pulsed ultraviolet laser and a high-speed camera equipped with an image intensifier. The output wavelength of the laser can be finely tuned to the specific absorption line of the target free radical in the range of 280 nm to 340 nm. The laser output is shaped into a thin sheet beam that passes through the combustion region. The high-speed camera has a corresponding narrowband filter for capturing the laser-induced fluorescence signal of target free radicals such as OH, NO, and NH to provide a two-dimensional relative concentration distribution of the target free radicals. The Raman scattering system consists of a high-power continuous wave laser, a confocal optical path, and a high-sensitivity spectrometer, used to quantitatively measure the absolute concentrations of N2, O2, H2, NH3, H2O, CO2, and CO inside the burner; The high-speed flame imaging system includes a high-speed visible light camera or infrared camera to record the transient morphology, propagation speed, stability boundary, and quenching process of activated ammonia combustion flame, and to extract the geometric feature parameters and combustion oscillation frequency of the flame using image analysis software; the high-speed flame imaging system also includes a flame chemiluminescence imaging system equipped with an ICCD to record the chemiluminescence signals of specific excited-state intermediates such as OH, CH, and NH to reflect the distribution and intensity of the combustion reaction region.

[0017] The beneficial effects of using this invention are: by integrating a high-precision gas supply unit, interchangeable activation modules, a burner test chamber with rich optical access, and an optical diagnostic system, this invention achieves comprehensive, real-time, and high-precision monitoring of key parameters throughout the entire process of activated ammonia combustion.

[0018] This invention, through the tight integration of an optical diagnostic system and a thermodynamic monitoring unit, coupled with an advanced control system, can reveal the complex dynamic coupling mechanism between activation parameters, flow field characteristics, chemical reaction kinetics, and pollutant generation during the combustion of activated ammonia.

[0019] The control system of this invention introduces a machine learning-based pattern recognition module, which can automatically identify combustion instability modes, pollutant generation trends, and nonlinear correlations between activation efficiency and combustion performance from massive multi-dimensional data. This significantly improves the efficiency and depth of data analysis and provides fast, accurate, and predictive guidance for the iterative optimization of burners.

[0020] The testing system provided by this invention offers unprecedentedly refined process diagnostic capabilities, enabling the design and optimization of activated ammonia burners to shift from empirical trial-and-error to a systematic engineering approach based on scientific data and mechanistic understanding. This will significantly shorten the R&D cycle, reduce R&D costs, and accelerate the industrialization of high-performance, low-emission activated ammonia burners, thereby providing crucial technical support for promoting the widespread application of ammonia fuel as a clean energy source. By enhancing the systematic optimization capabilities of burner performance, this invention effectively achieves precise control and minimization of pollutant emissions such as nitrogen oxides while ensuring high combustion efficiency and flame stability, thus achieving an optimal balance between environmental protection and energy efficiency. Attached Figure Description

[0021] Figure 1 A schematic diagram of the overall structure of the activated ammonia burner testing system of the invention; Figure 2 A schematic diagram of the module connections for the activated ammonia burner testing system of the invention; Figure 3 This is a schematic diagram of the module connections for the activation module; Figure 4 A schematic diagram of the module connections for the burner test chamber; Figure 5 This is a schematic diagram of the burner mounting flange in the burner test chamber. Figure 6 A schematic diagram showing the location of the linear motion pair and the through-hole in the burner mounting flange; Figure 7 This is a schematic diagram of the module connections for an optical diagnostic system; Figure 8 This is a schematic diagram of the module connections for the exhaust monitoring unit; Figure 9 This is a diagram of the shape of a multi-dimensional adjustable burner.

[0022] Figure 10 This is a schematic diagram of the internal structure of a multi-dimensional adjustable burner.

[0023] Figure 11 This is a schematic diagram showing the arrangement of the first and third gas pipes on the end face of the burner body. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this technical solution clearer, the following detailed description, in conjunction with specific embodiments, further illustrates this technical solution. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of this technical solution.

[0025] like Figure 1 , Figure 2As shown, the present invention proposes a testing system 100 for activated ammonia burners. Its overall architecture is sophisticated, with each component working collaboratively. Its core function is to achieve refined monitoring and mechanism analysis of key parameters throughout the entire chain, from fuel activation and mixing to combustion and product emissions. The testing system 100 for activated ammonia burners includes: a gas supply unit 110, an activation module 120, a burner testing chamber 130, an optical diagnostic system 140, a thermodynamic monitoring unit 150, an exhaust monitoring unit 160, and a control system 170. These units are tightly coupled, jointly constructing a comprehensive testing platform capable of providing in-depth insights into the combustion mechanism of activated ammonia.

[0026] The gas supply unit 110 is primarily responsible for accurately metering, mixing, and delivering the ammonia fuel, oxidant, and optional diluent or activating auxiliary gas required for the experiment. The core design feature of this unit 110 is providing high-precision, high-stability gas flow and pressure control. It includes multiple high-precision mass flow controllers 111, multiple pressure regulating valves 112, a gas mixer 113, and a fuel preheater 114. The high-precision mass flow controllers 111 employ Coriolis mass flow meters or thermal mass flow meter technology, selecting compatible materials (such as 316L stainless steel or Hastelloy) to suit the characteristics of different gases (e.g., the corrosiveness of ammonia, the low density of hydrogen) and ensuring excellent sealing performance. Specifically, the mass flow controller for ammonia (NH3) has a range of 0 to 200 liters / minute (standard conditions), while the controllers for air and optional hydrogen (H2) or oxygen (O2) have a range of 0 to 500 liters / minute (standard conditions). All controllers achieve a flow measurement accuracy of ±0.2% of the reading plus ±0.05% of full scale, with a response time of less than 300 milliseconds. This enables precise control of the fuel-oxidant ratio over a wide flow range and supports rapid adjustment under dynamic operating conditions. Each gas line is equipped with a high-precision pressure regulating valve 112 connected in series, employing a two-stage pressure reducing or back pressure regulating valve design to ensure that the gas pressure entering the mass flow controller and subsequent modules remains stable at a preset value, with pressure fluctuations controlled within ±0.05%FS, thereby minimizing the impact of pressure fluctuations on flow measurement. The gas mixer 113 can be configured with various structures to suit experimental needs. For example, a static mixer with internal spiral blades or a perforated plate structure can be used to increase the fluid contact area and agitation, ensuring uniform mixing of ammonia, air, and other auxiliary gases before they enter the activation module 120 or the burner test chamber 130, achieving a mixing uniformity of over 98%. In scenarios requiring faster dynamic mixing response, a vortex-type dynamic mixing chamber can be used, achieving uniform mixing within microseconds through high-speed rotation or alternating injection mechanisms. The fuel preheater 114 employs high-power electric heating with nickel-chromium alloy heating wires wrapped in multi-layer ceramic fiber insulation to minimize heat loss. Multiple armored K-type thermocouples are arranged along the gas flow direction, combined with a PID (proportional-integral-derivative) controller, to precisely control the temperature of the mixed gas entering the burner within a wide range from ambient temperature to 500℃, with temperature fluctuations controlled within ±0.5℃ in steady state, accurately simulating various fuel preheating conditions. All gas pipelines are made of seamless 316L stainless steel and are electropolished. All pipeline connections use VCR or Swagelok compression fittings to ensure high-pressure sealing.

[0027] like Figure 3As shown, the activation module 120 is designed with a highly modular and interchangeable or combinable structure, enabling flexible adaptation to different ammonia activation technology routes. It mainly includes a catalytic pre-cracking unit 121 or a plasma activation unit 122. This design greatly improves the system's versatility and research efficiency.

[0028] Specifically, the catalytic pre-cracking unit 121 is designed as a tubular or plate reactor, with its main material being high-temperature resistant and corrosion-resistant quartz glass or Inconel 625 high-temperature alloy. The tubular reactor has a diameter ranging from 10 mm to 50 mm and a length adjustable up to 500 mm; the plate reactor employs a microchannel or macrochannel structure with channel dimensions between 1 mm and 5 mm. The reactor is filled with a high-performance catalyst. Preferably, the catalyst is a noble metal-based material (e.g., platinum (Pt), ruthenium (Ru), or nickel (Ni)-based) supported on a high specific surface area carrier, such as γ-alumina (γ-Al₂O₃), zirconium oxide (ZrO₂), or silicon carbide (SiC). The typical catalyst loading is 0.5 wt% to 5 wt%, with a particle size controlled between 0.2 mm and 2 mm to balance reactivity and mass transfer efficiency. The reactor is externally encased in high-power electric heating wires (such as Cantal alloy) and multiple layers of insulation material. A PID temperature controller precisely controls the reactor wall temperature within the range of 300℃ to 900℃, with a temperature gradient controlled within ±2℃ / cm. Multiple thermocouples, preferably S-type thermocouples (platinum-rhodium 10-platinum) with a diameter of 0.25 mm and a response time of less than 50 milliseconds, are integrated along the axial and radial directions of the catalyst bed inside the reactor for real-time monitoring of temperature distribution and hot spots within the catalyst bed. Furthermore, an online gas sampling port is located at the reactor outlet. This port uses a heated sampling probe connected via a heated pipeline to a high-precision gas chromatograph (GC) or a tunable semiconductor laser absorption spectroscopy (TDLAS) system. The GC is equipped with a thermal conductivity detector (TCD) or a flame ionization detector (FID) for real-time quantitative analysis of ammonia (NH3), hydrogen (H2), nitrogen (N2), and any small amounts of unpyrolyted products and byproducts. The GC system achieves a detection limit of 5 ppm for H2 and NH3, with an analysis cycle of 15 to 60 seconds, and is equipped with an automatic injection valve and a carrier gas (helium or argon) system. The TDLAS system, on the other hand, uses a mid-infrared laser diode to scan specific absorption peaks of H2 and NH3, enabling rapid online monitoring with a detection limit of 1 ppm and a response time of less than 1 second. This provides real-time, high-precision quantitative data for activation efficiency and product composition.

[0029] Furthermore, the plasma activation unit 122 can be selected from a dielectric barrier discharge (DBD) plasma generator or a microwave plasma generator to meet the research needs of different activation mechanisms. The DBD plasma generator adopts a coaxial or parallel plate electrode structure, with the electrode material preferably being 316L stainless steel or alumina ceramic, and the dielectric material being high-purity quartz glass or alumina ceramic. The dielectric thickness ranges from 0.5 mm to 3 mm, and the discharge gap is controlled between 1 mm and 5 mm. This generator is powered by a high-frequency, high-voltage power supply, and its output frequency can be continuously adjusted within the range of 1 kHz to 100 kHz, with a peak voltage of up to 20 kV and an output power that can be precisely controlled within the range of 50 W to 2 kW. The microwave plasma generator adopts a waveguide or resonant cavity structure, powered by a solid-state microwave power supply or a magnetron, with an operating frequency typically of 2.45 GHz and an output power that can be continuously adjusted within the range of 100 W to 5 kW to generate high-energy-density plasma. Each plasma generator is equipped with a high-voltage probe (bandwidth DC to 100 MHz) and a current probe (bandwidth DC to 50 MHz) for real-time measurement of the voltage and current waveforms of plasma discharge. The plasma dissipation power is then precisely calculated using the Lissajous figure method or direct integration method to quantify the energy input. To further diagnose the active species within the plasma, an optical window made of high-purity quartz glass resistant to ultraviolet radiation is installed at the plasma generator's outlet. This window is connected to a fiber optic spectrometer for emission spectroscopy (OES). The fiber optic spectrometer is equipped with a high-sensitivity CCD or CMOS detector, with a detection wavelength range of 200 nm to 900 nm and a spectral resolution better than 0.3 nm. Its grating selection can be optimized based on the spectral characteristics of the target free radicals (e.g., 1200 lines / mm) to identify and quantify the active free radicals present in the plasma, such as NH* (336 nm), OH* (309 nm), and Hα (656 nm), and their relative concentrations, thereby providing a deeper understanding of the activation mechanism of ammonia in the plasma. All diagnostic data were analyzed using specialized software for spectral line identification, background subtraction, intensity correction, and temperature calculation using the Boltzmann diagram method, thereby quantifying the generation efficiency of active species.

[0030] like Figure 4As shown, the burner test chamber 130 employs a double-layer water-cooled or air-cooled 316L stainless steel structure. The exterior uses a welded structure to ensure strength and sealing, while the interior is lined with high-purity alumina or silicon carbide high-temperature resistant ceramic materials to effectively isolate the high-temperature combustion zone, ensuring controllable chamber wall temperature (typically maintained below 50°C) and long-term stability of the test environment. The internal dimensions of the chamber are designed according to the size range of the burner under test, with typical internal dimensions of 300 mm × 300 mm × 500 mm (length × width × height). At least four sets of optical access windows 131 are symmetrically arranged on the chamber wall along multiple optical path directions. These windows are made of high-purity synthetic quartz (suitable for the ultraviolet to visible light band, 200 nm to 800 nm) or sapphire (suitable for the visible to near-infrared band, 400 nm to 2000 nm), with optical transmittance better than 95% within the specified wavelength range, and maintaining good optical performance and mechanical strength even under high temperature and high pressure environments. The window features a tapered design and integrated purge gas interface to reduce wall effects and optical distortion, effectively preventing the deposition of combustion products or tracer particles on the window surface and ensuring the purity of optical diagnostic signals. The cavity houses an adjustable burner mounting flange 132, employing a universal joint and slide rail structure to flexibly accommodate activated ammonia burners of various sizes and structures, ranging from 20 mm to 150 mm in diameter and 100 mm to 400 mm in length. Fine adjustments are allowed in the x, y, and z directions, as well as pitch, yaw, and roll angles. Multiple inlets are provided within the cavity for precise introduction of fuel, air, and activation products, while multiple outlets discharge combustion products. All inlets and outlets utilize water-cooled sealing structures (such as O-rings or metal gaskets) to prevent high-temperature gas leakage and are equipped with quick-connect mechanisms for easy replacement. A multi-channel pressure sensor 133 is installed on the top or side of the combustion chamber. The sensor adopts a high-sensitivity piezoelectric (PZT) or strain gauge design, with a range of 0 to 200 kPa gauge pressure, a minimum detectable pressure fluctuation of 1 Pa, and a response frequency of up to 200 kHz. It is used to monitor the static pressure and dynamic pressure pulsation inside the combustion chamber in real time, as well as capture transient signals of combustion instability events (such as thermoacoustic oscillations), providing key data for combustion stability analysis. The pressure sensor is installed with a water-cooled probe to ensure stable operation for extended periods in high-temperature environments.

[0031] like Figure 5As shown, in the burner mounting flange 132, flange 1321 is installed at the end of the activation module 120. Flange 1321 is bolted to the end of the activation module 120 and seals the connection. Flange 1321 encloses the internal cavity of the activation module 120. It serves as a connection structure between the activation module 120 and the burner test chamber 130, and also as a carrier for adjusting the burner's three-dimensional spatial position module. Three linear motion pairs 1322 are installed on the end face of flange 1321. Each linear motion pair 1322 has a linear motion terminal and serves as a power device for adjusting the burner's position and angle. The linear motion pair 1322 can be a combination of a threaded rod and a threaded slider with a track. The driving component of the threaded rod is a stepper motor. The stepper motor's rotation drives the threaded rod to rotate, thereby driving the threaded slider to move linearly along the track. Figure 6As shown, the linear motion pairs 1322 are arranged radially at equal intervals around the center of the flange 1321. This arrangement allows for precise adjustment of the threaded slider movement to drive the burner's movement and deflection. One end of each of the three hinged arms 1325 is hinged to the linear motion terminal of the three linear motion pairs 1322, and the other end is hinged to the outer periphery of the sleeve clamp 1327, forming a support and transmission component for the sleeve clamp 1327. During the movement of the linear motion pairs 1322, the threaded slider, through the hinged arms 1325, can drive the sleeve clamp 1327 to move in a controllable manner, such as synchronously bringing the lower ends of the hinged arms 1325 together, synchronously moving them apart, moving a single hinged arm 1325, or moving both hinged arms 1325, among other combinations of actions. The locking screw 1326 is installed at the connection of the branch folding arm of the folding arm 1325. It is used to pre-adjust the folding angle of the folding arm 1325 according to preset parameters, thereby limiting the maximum operating range of the burner. The locking screw 1326 can set a predetermined angle for the branch folding arm of the folding arm 1325 according to the design, expanding the controllable operating range and position of the burner. The sleeve clamp 1327 is used to install the burner and stably clamp it. The sleeve clamp 1327 is made of high-temperature resistant alloy material. A custom sleeve clamp 1327 is required for each different specification of combustion heat. The connection between the sleeve clamp 1327 and the outer periphery of the burner needs to be sealed. The sleeve 1323 is installed between the activation module 120 and the burner test chamber 130. The composite corrugated cover 1328 is closed at the end opening of the sleeve 1323 and works with the sleeve 1323 to form a heat-insulating cavity between the activation module 120 and the burner test chamber 130. The composite corrugated cover 1328 is made of composite material, with one layer being heat insulation material and metal armor layers sandwiched on both sides. The metal armor layers prevent the heat insulation material from tearing, which would cause heat to flow back into the activation module 120 and prevent deflagration. The composite corrugated cover 1328 is sealed at the connection points with the sleeve clamp 1327 and the sleeve 1323. The ventilation pipe 1324 is located in the sleeve 1323 and is used to reduce the temperature of the insulation cavity through active ventilation and to prevent combustion gases from entering the insulation cavity and causing deflagration. The ventilation pipe 1324 in the burner mounting flange 132 uses a dual-pipe configuration (one extraction and one release) to circulate inert gas into the insulation cavity (maintaining positive pressure in the insulation cavity). The inert gas is cooled by heat exchange outside before entering the insulation cavity. Flange 1321 has a through hole 1329 for passing through a gas supply pipe that supplies gas to the burner. The end of the gas supply pipe is connected to the burner. The number of gas supply pipes and through holes 1329 corresponds. If multiple gases need to be supplied, through holes 1329 are opened accordingly.

[0032] like Figure 7As shown, in one embodiment of the present invention, the optical diagnostic system 140 is the core tool for achieving "white-box" analysis of the activated ammonia combustion process. It acquires rich information on the internal flow field, temperature field, component field, and flame morphology of the burner through non-invasive optical measurement methods. The system 140 includes: a particle image velocimetry (PIV) system 141, a coherent anti-Stokes Raman scattering (CARS) system 142 or a tunable semiconductor laser absorption spectroscopy (TDLAS) temperature measurement system 143, a planar laser-induced fluorescence (PLIF) system 144, and a high-speed flame imaging system 145.

[0033] Specifically, the PIV system 141 is used to measure the transient two-dimensional velocity vector field inside the burner. It includes a dual-pulse Nd:YAG laser, a high-resolution sCMOS camera, and a high-precision synchronization controller. The dual-pulse Nd:YAG laser provides a single-pulse laser output with an energy of not less than 150 millijoules at a wavelength of 532 nm, a pulse width of less than 8 nanoseconds, and a pulse interval that is continuously adjustable from 0.5 microseconds to 1 millisecond, used for dual-pulse illumination of tracer particles. The laser beam passes through a beam-splitting and shaping optical system to form a uniform laser sheet with a thickness of 0.5 mm to 1 mm, and passes through a designated measurement area of ​​the burner test cavity 130. The high-resolution sCMOS camera has an image resolution of not less than 2560x2160 pixels and a full-frame acquisition rate of not less than 15 Hz. It is equipped with a high-throughput, low-distortion objective lens and a 532 nm narrowband filter (bandwidth ±5 nm) for efficiently capturing images of tracer particle scattering. The tracer particles are typically alumina (Al2O3) or silica (SiO2) microparticles with a diameter of 1 to 5 micrometers. Their density is well matched with the airflow density. They are uniformly introduced into the airflow to be measured through a sophisticated particle generator (such as a cyclone generator or an ultrasonic atomizer). The PIV system uses specialized image processing software (such as LaVision DaVis or TSI Insight) to calculate particle displacement based on a cross-correlation algorithm, thereby obtaining the transient two-dimensional velocity vector field inside the burner. Its spatial resolution can reach 0.5 mm, the velocity measurement accuracy is better than 1.5%, and the maximum measurable velocity reaches 200 m / s.

[0034] Furthermore, the CARS system or TDLAS temperature measurement system is used to accurately measure the transient temperature field inside the burner. The CARS system consists of a pump laser (e.g., a tunable Nd:YAG laser with its fundamental or frequency-doubled output, or a dye laser) and a Stokes laser (e.g., a dye laser or an optical parametric oscillator). The pump laser is typically a 532 nm frequency-doubled output Nd:YAG laser with an energy of 50 millijoules, while the Stokes laser is tunable to near the vibrational Raman resonance frequency of nitrogen (N2) or oxygen (O2) with an energy of 5 millijoules. Three laser beams (two pump beams and one Stokes beam) enter the combustion region through a precise beam combining and focusing optical system, in a collinear or non-collinear phase-matched manner, and generate a CARS signal at the focal point. The CARS signal exhibits high directionality and coherence, and can be effectively separated by spatial filters (such as apertures) and narrowband filters (used to filter out pump and Stokes light). It is then fed into a high-resolution spectrometer (e.g., spectral resolution better than 0.1 cm⁻¹, equipped with a high-sensitivity ICCD detector) for detection. By analyzing the shape of the CARS spectrum (e.g., the intensity ratio of the Stokes and anti-Stokes branches of the N₂ vibrational line) and line broadening, local gas temperature information can be retrieved. The CARS system achieves nanosecond-level temporal resolution and sub-millimeter-level (better than 100 micrometers) spatial resolution, with a temperature measurement accuracy better than 1.5% in the temperature range of 300 K to 2500 K. The TDLAS temperature measurement system uses two or more near-infrared laser diodes of different wavelengths (e.g., distributed feedback (DFB) lasers or external cavity semiconductor lasers (ECLDs)) to scan specific temperature-sensitive molecular absorption lines (such as the absorption lines of H₂O or CO₂). The transient temperature of the gas is obtained by measuring the changes in peak intensity and line shape parameters (such as linewidth and absorption area) of different absorption spectral lines with temperature. TDLAS systems typically employ wavelength modulation spectroscopy (WMS) to improve signal-to-noise ratio and measurement accuracy. They achieve millisecond-level temporal resolution and centimeter-level (better than 5 mm) spatial resolution, with measurement accuracy better than 2% at temperatures below 1500 K. Furthermore, the multi-point thermocouple array is used to supplement areas not covered by CARS or TDLAS and to measure wall temperatures. It employs armored S-type thermocouples (platinum-rhodium 10-platinum), with a diameter of 0.3 mm, a temperature range of 0°C to 1700°C, an accuracy of ±1°C, and a response time of less than 50 milliseconds, arranged in a matrix (e.g., 5x5 or higher density) to provide temperature data for critical locations inside the burner, particularly in complex areas such as the flame root and near-wall region.

[0035] Furthermore, the PLIF system 144 is used to measure the spatial two-dimensional relative concentration distribution of key reactive free radicals (such as OH, NO, NH) inside the burner. This system includes a tunable pulsed ultraviolet laser, such as an OPO (Optical Parametric Oscillator) or dye laser, whose fundamental frequency output is harmonicized / tripled to generate ultraviolet light. The output wavelength can be finely tuned in the range of 280 nm to 340 nm to accurately excite specific absorption lines of target free radicals (e.g., the A2Σ+←X2Π transition of OH free radicals in the 308-310 nm range, and the A3Π←X3Σ- transition of NH free radicals near 336 nm). The laser pulse energy is not less than 10 mJ, and the pulse width is less than 8 nanoseconds. The laser beam is shaped into a sheet-like beam with a thickness of approximately 0.2 mm, which passes through the combustion region. The system also includes a high-speed camera equipped with an image intensifier (ICCD) for capturing laser-induced fluorescence signals. The ICCD camera has an image resolution of at least 1024x1024 pixels, a pixel size of 13 μm × 13 μm, and nanosecond-level (10 nanoseconds to 1 microsecond) gate width adjustment capability. Combined with high quantum efficiency (greater than 40%), it can effectively filter out background radiation and capture transient fluorescence signals. The camera is equipped with a corresponding narrowband filter (bandwidth ±3 nm) to further filter out background interference such as Rayleigh scattering, Mie scattering, and chemiluminescence, receiving only the fluorescence signal of the target free radical. Through image processing (such as background subtraction, flat-field correction, and fluorescence signal intensity correction) and calibration (such as calibration in a gas of known concentration or using rate equation model inversion), the PLIF system can provide a two-dimensional relative concentration distribution of the target free radical, with a spatial resolution better than 0.1 mm and a temporal resolution better than 20 nanoseconds, thereby finely characterizing the structure and transient evolution of the combustion reaction region. In addition, the optical diagnostic system also includes a Raman scattering system, which consists of a high-power continuous-wave laser (e.g., the fundamental or harmonic output of an Nd:YAG laser, or a multimode fiber laser with a power of up to 100 watts), a confocal optical path, and a high-sensitivity spectrometer. The laser is transmitted through an optical fiber and focused at the measurement point; the scattered signal is collected by the confocal probe and detected by the spectrometer. This system is used to quantitatively measure the absolute concentrations of the main stable components inside the burner (such as N2, O2, H2, NH3, H2O, CO2, and CO). Quantification is achieved by analyzing the Raman scattering peak intensity of each component and combining it with calibration curves. Its spatial resolution can reach 0.5 mm, its temporal resolution can reach 1 second, and its accuracy is better than 3%, providing crucial data for the mass balance and stoichiometric analysis of the combustion process.

[0036] Furthermore, the high-speed flame imaging system 145 includes a high-speed visible light camera or infrared camera with a frame rate of up to 20,000 frames per second and an image resolution of no less than 1024x1024 pixels. It is equipped with a high-throughput objective lens to record the transient morphology, propagation speed, stability boundary, and extinguishing process of the activated ammonia combustion flame. Through specialized image analysis software, geometric feature parameters of the flame (such as flame length, width, area, and center position), as well as the combustion oscillation frequency and amplitude, can be extracted. The high-speed camera achieves sub-microsecond precise time synchronization with the PIV, PLIF laser, and data acquisition system 170 via a synchronization controller to correlate the dynamic evolution of the flame morphology with the flow field and component field. The system also includes a flame chemiluminescence imaging system equipped with an ICCD to record the chemiluminescence signals of specific excited-state intermediate products (such as OH*, CH*, and NH*) to reflect the distribution and intensity of the combustion reaction region. Its ICCD camera has an adjustable gate width of 5 nanoseconds. By selecting appropriate narrowband filters, it can capture signals of OH* (309 nm), CH* (431 nm), and NH* (336 nm) respectively, enabling regional diagnosis of different chemical reaction pathways. This chemiluminescence imaging provides direct visualization of the chemical activity inside the flame, further enhancing our understanding of the combustion process.

[0037] In one embodiment of the present invention, the exhaust gas monitoring unit 160 is used to accurately measure key components in combustion products, particularly pollutants. This unit includes a multi-component infrared gas analyzer 161, a chemiluminescent nitrogen oxide analyzer 162, and a tunable semiconductor laser absorption spectroscopy (TDLAS) ammonia analyzer 163. The multi-component infrared gas analyzer 161 employs non-dispersive infrared (NDIR) technology, enabling simultaneous and high-precision measurement of the concentrations of CO and CO2 in combustion products. Its CO measurement range is 0 to 5000 ppm with an accuracy better than ±0.5% of full scale; the CO2 measurement range is 0 to 20% (volume) with an accuracy better than ±0.5% of full scale. The chemiluminescent nitrogen oxide analyzer 162 is used to measure the concentrations of NO, NO2, and total NOx in the exhaust gas. Its measurement range is 0 to 1000 ppm with an accuracy better than ±0.3% of full scale and a response time of less than 2 seconds. Accurate NO2 measurement can be achieved through a built-in NO2 converter. The TDLAS ammonia analyzer 163 employs a mid-infrared (e.g., 3-micron band) or near-infrared (e.g., 1.5-micron band) laser diode to perform high-precision scanning and measurement of specific absorption peaks of ammonia, enabling high-precision real-time monitoring of unburned ammonia (NH3 slip). Its detection limit is as low as 0.05 ppm, with a response time of less than 0.5 seconds, and it exhibits excellent anti-interference capabilities against interfering gases such as H2O and CO2. The exhaust gas analysis system ensures the sampled gas remains stable before entering the analyzer through a fully heated sampling pipeline (maintained at 180°C) and a high-efficiency condensation and dehumidification unit, preventing component condensation or reaction, especially in high-humidity environments. Furthermore, the unit includes a magnetic oxygen analyzer for accurately measuring the oxygen content in the exhaust gas, with a measurement range of 0 to 25% (by volume) and an accuracy better than ±0.1% of full scale. By combining this with fuel flow data, the air-fuel ratio and excess air coefficient of the combustion process can be accurately determined.

[0038] like Figure 8As shown, in one embodiment of the present invention, the control system 170 is the brain of the entire testing system, used to integrate, synchronize, and analyze data from all sensors and diagnostic devices, and to precisely control the entire testing process. The system consists of a high-performance industrial PC platform (e.g., equipped with an Intel Xeon processor, 64GB DDR4 ECC RAM, and high-speed SSD storage) or a distributed control system (DCS), multiple high-speed data acquisition cards, a real-time control module, and customized data analysis and visualization software. The high-speed data acquisition cards are used to synchronously acquire all analog signals from mass flow controllers, pressure sensors, thermocouples, photodetectors, etc., and control the start / stop and parameter adjustment of lasers, cameras, solenoid valves, and heaters through digital I / O modules. The real-time control module 171 is built based on a field-programmable gate array (FPGA) or a high-speed microcontroller, used to achieve nanosecond to millisecond-level time synchronization and trigger control, ensuring precise coordination between optical diagnostic systems such as PIV, PLIF, and CARS and the burner's operating status.

[0039] Furthermore, the customized data analysis and visualization software adopts a modular design and is developed based on LabVIEW or Python / C++, integrating a variety of advanced data processing algorithms. These algorithms include: image processing algorithms (such as the adaptive cross-correlation algorithm in PIV vector field calculation, the self-absorption model for PLIF fluorescence intensity correction and inversion, and the Canny operator and level set method for flame edge extraction), spectral analysis algorithms (such as nonlinear least squares fitting for CARS spectral inversion temperature, and the Boltzmann diagram method for OES spectral line identification and quantification), time series analysis algorithms (such as Fast Fourier Transform (FFT), wavelet analysis for combustion oscillation frequency and pattern recognition, and Recursive Quantization Analysis (RQA) for nonlinear dynamic analysis), and multi-dimensional data fusion algorithms (such as Principal Component Analysis (PCA) and Independent Component Analysis (ICA) for dimensionality reduction and feature extraction of multi-source data). This software can correlate and visualize all collected data in real time in three dimensions. For example, it can overlay transient flow fields, temperature fields, active free radical component fields, and high-speed flame morphology in the same three-dimensional space, and provide powerful data statistical analysis (mean, variance, probability density function, correlation), trend prediction, and anomaly diagnosis functions. The system 170 also integrates a machine learning-based pattern recognition module, which uses support vector machines (SVM), convolutional neural networks (CNN), or deep learning algorithms to automatically identify unstable modes in the combustion process (such as the type and intensity of thermoacoustic oscillations), pollutant generation trends (such as the thermodynamic path of NOx generation), and nonlinear correlations between activation efficiency and combustion performance from massive amounts of multi-dimensional data, thereby providing in-depth guidance and predictive suggestions for the optimized design of burners.

[0040] The testing system for activated ammonia burners provided by this invention, through the above-mentioned refined design and multi-functional integration, achieves comprehensive, real-time, and high-precision diagnosis of the activated ammonia combustion process, providing unprecedented insights for the research and development and optimization of burners.

[0041] Example 1: Steady-state operation characteristics analysis of a catalytic pre-cracking ammonia combustor In one specific embodiment, the test system 100 of the present invention for an activated ammonia burner was used to study the steady-state operating characteristics of the combustion chamber of an ammonia fuel micro gas turbine employing catalytic pre-cracking technology.

[0042] Experimental setup: Fuel and air supply unit 110: Ammonia (NH3, purity 99.99%) is supplied through a high-precision mass flow controller 111 (range 0-100 SLPM, accuracy ±0.2% of reading).

[0043] Air is supplied via a high-precision mass flow controller 111 (range 0-300 SLPM, accuracy ±0.2% of reading).

[0044] Gas mixer 113 employs a static mixer to ensure that ammonia and air are uniformly mixed before entering the pre-cracking unit.

[0045] The fuel preheater 114 is set to 300°C to simulate the waste heat recovery from gas turbine exhaust.

[0046] Activation module 120: Catalytic pre-cracking unit 121 was selected. The reactor was an Inconel 625 tubular reactor with a diameter of 20 mm and a length of 150 mm, filled with 2 wt% Ru / γ-Al2O3 catalyst with a particle size of 1 mm.

[0047] The catalyst bed temperature is precisely controlled at 750℃±2℃ using an external electric heating wire.

[0048] The catalytic pre-crack products (NH3 / H2 / N2 mixture) are connected to the TDLAS ammonia analyzer and GC via a heated sampling pipeline to monitor NH3 conversion and H2 production in real time.

[0049] Burner test chamber 130: Double-layered water-cooled stainless steel cavity, internal dimensions 200 mm × 200 mm × 300 mm.

[0050] Install the ammonia burner to be tested (premixed swirl burner, inlet diameter 30 mm) and ensure positional accuracy via the adjustable mounting flange 132.

[0051] Four sets of sapphire optical access windows 131 are provided on the cavity wall to ensure that the optical path of the optical diagnostic system is unobstructed.

[0052] Pressure sensor 133 at the top of the chamber monitors the static pressure and maintains it at ambient pressure.

[0053] Optical Diagnostic System 140: PIV System 141: Dual-pulse Nd:YAG laser (532 nm, 100 mJ / pulse), pulse interval 10 μs. sCMOS camera (2560 x 2160 pixels), frame rate 15 Hz. Alumina tracer particles (2 μm) are introduced via airflow. Flow field is measured in the burner throat and diffuser region.

[0054] CARS temperature measurement system: Nd:YAG pumped laser (532 nm) and dye Stokes laser, measuring the vibrational CARS signal of N2 in the flame region to obtain the transient temperature field.

[0055] PLIF system 144: OPO frequency doubling generates 309 nm ultraviolet light to excite OH radicals. An ICCD camera (1024x1024 pixels) with a gate width of 50 nanoseconds is used to acquire the two-dimensional relative concentration distribution of OH radicals.

[0056] High-speed flame imaging system 145: High-speed visible light camera (1024x1024 pixels, 5000 frames / second) to record transient flame morphology.

[0057] Exhaust monitoring unit 160: The multi-component infrared gas analyzer 161 measures CO and CO2.

[0058] The chemiluminescent nitrogen oxide analyzer 162 measures NOx.

[0059] The TDLAS 163 ammonia analyzer measures unburned NH3.

[0060] A magnetic oxygen analyzer measures O2.

[0061] Control System 170: A high-performance industrial PC platform and a high-speed DAQ card synchronously acquire all sensor signals and optical diagnostic data.

[0062] The real-time control module 171 precisely synchronizes the laser, camera, and gas flow controller.

[0063] Customized software 174 performs PIV vector field calculations, CARS temperature inversion, PLIF image processing, and real-time visualization and correlation analysis of all data.

[0064] Experimental Procedure and Data Analysis: Under steady-state operating conditions, the conversion rate of NH3 in catalytic pre-cracking is set to 90%, that is, the fuel composition entering the burner is 10% NH3, 45% H2, and 45% N2 (molar ratio). At the same time, the air flow rate is adjusted to make the equivalence ratio (φ) 0.85.

[0065] Activation product analysis: TDLAS and GC data showed that the NH3 conversion rate remained stable at 90.2% ± 0.5%, and the H2 production remained stable at 90.5% ± 0.8% of the theoretical maximum hydrogen production from the input ammonia. This ensured the stable output of the activation module and provided a reliable fuel composition for subsequent combustion studies.

[0066] Flow field characteristics: Transient flow field data obtained from the PIV system showed an average axial velocity of 25 m / s at the burner throat and a turbulence intensity of 15%. The recirculation zone at the flame root (5 mm from the burner outlet) was 10 mm in size, providing a stable ignition source. PIV data revealed the mixing characteristics of pre-pyrolysis products with air after entering the burner, demonstrating the critical influence of swirl intensity on the mixing process.

[0067] Temperature field distribution: The CARS system obtained transient temperatures up to 1950K±30K along the central axis of the flame, with a temperature gradient of up to 200K / mm near the flame front. The two-dimensional temperature field distribution map clearly shows the shape of the flame region and the expansion of the high-temperature region, consistent with the design objectives.

[0068] OH radical distribution: The two-dimensional relative concentration distribution map of OH radicals obtained by the PLIF system shows that OH radicals are mainly concentrated in the flame front region, with their peak concentration located on the periphery of the high-temperature region, indicating the location of the main exothermic reaction zone. The OH radical concentration is highly correlated with the temperature field measured by CARS, proving the role of OH as an important intermediate product in the combustion process.

[0069] Flame morphology and stability: The flame recorded by the high-speed flame imaging system is a stable cone shape, and no macroscopic combustion oscillations, flame rise, or backfire were observed. Image analysis shows that the flame length is stable at 80 mm ± 2 mm, and the width is stable at 45 mm ± 1 mm.

[0070] Pollutant emissions: Data from the exhaust gas analysis unit showed that, under the condition of φ=0.85, the NOx emission concentration was 120 ppm (equivalent to 15% O2), and the unburned NH3 (NH3 slip) concentration was 5 ppm. Both CO and CO2 concentrations were below the detection limit, indicating high combustion efficiency. Oxygen content analysis showed an actual excess air coefficient of 1.17.

[0071] in conclusion: Through the above embodiments, the testing system 100 of this invention successfully achieved a comprehensive and high-precision diagnosis of the steady-state operation of a catalytic pre-cracking ammonia burner. The system not only quantified fuel activation efficiency but also, for the first time, non-invasively acquired the transient flow field, temperature field, and OH radical distribution within the flame, as well as the macroscopic morphology of the flame, in a micro gas turbine-scale ammonia burner through multimodal optical diagnostics. These data collectively reveal the mixing, ignition, and combustion reaction kinetics of ammonia pre-cracking products in the burner, as well as the pollutant formation mechanism. For example, simultaneous analysis of PIV and PLIF data shows that the existence of the recirculation zone and its flow field characteristics are crucial for the stable generation of OH radicals and the anchoring of the flame front. NOx and NH3 emission data directly reflect the environmental performance of the burner under specific activation conditions. These in-depth mechanistic data provide a solid scientific basis for further structural optimization and operational parameter adjustment of this type of ammonia burner.

[0072] Comparative Example To further highlight the technical advantages of the activated ammonia burner testing system 100 of this invention, a typical prior art "black box" testing system will be constructed below as a comparative example. Such traditional testing systems are typically limited to the measurement of macroscopic parameters and lack the ability to provide detailed diagnostics of the microscopic physicochemical phenomena within the combustion process.

[0073] Existing "black box" testing system setup: A typical "black box" testing system usually includes: Fuel and air supply unit: Using only mass flow meters and pressure gauges with conventional accuracy (±1% of full scale), it is impossible to achieve rapid dynamic adjustment and high-precision mixing.

[0074] Activation module: It may not have an activation module, or the activation module may only provide heating function and cannot analyze the components of the activation product online.

[0075] Burner test chamber: Typically a single-layer metal structure, lacking water cooling or precise temperature control, and without an optical access window. The burner is fixed in its mounting and has no adjustment capability. Only one or two thermocouples and pressure sensors are installed at the exhaust port or on the chamber wall for point measurements.

[0076] Diagnostic system: No optical diagnostic system. It may be possible to take still photographs of the flame using a regular visible light camera, or simply observe the flame's shape with the human eye.

[0077] Thermodynamic parameter monitoring: Only a few points (such as inlet and outlet, exhaust port) are placed with thermocouples of conventional accuracy (±5℃), lacking information on the internal temperature field distribution.

[0078] Exhaust gas monitoring unit: May be equipped with a commercial NDIR analyzer to measure CO and CO2, and a chemiluminescence analyzer to measure NOx, but the accuracy and response speed are low, and it often cannot monitor H2 in NH3 slip or activation products. The sampling system usually does not have full-process heating or efficient dehumidification.

[0079] Data acquisition and control system: Based on simple PLC or data logger, the acquisition rate is slow, and it is impossible to achieve precise time synchronization between sensors and equipment. Data analysis mainly relies on manual post-processing and lacks automation and intelligent functions.

[0080] Limitations of existing "black box" testing technologies: Under the same catalytic pre-cracking ammonia burner testing task, using the above-mentioned "black box" system for testing will face the following significant limitations: Activation process: It is impossible to accurately assess the NH3 conversion rate and H2 production of catalytic pre-cracking in real time, and it is also impossible to monitor the temperature distribution of the catalyst bed, which leads to the inability to accurately control the degree of fuel activation and to detect catalyst poisoning or failure in a timely manner.

[0081] Missing flow field information: The transient velocity vector field and turbulence intensity distribution inside the burner cannot be obtained. Therefore, the efficiency of the fuel-air mixing process cannot be understood, the formation and stability of the recirculation zone cannot be identified, and thus the relationship between flow field characteristics and flame stability cannot be directly correlated.

[0082] Lack of temperature field information: Only approximate temperatures at a few points can be obtained, and the two-dimensional or three-dimensional transient temperature field distribution inside the combustion chamber cannot be obtained. This will result in the inability to accurately identify the flame front location, high-temperature regions, and temperature gradients, and will also prevent the analysis of the impact of hot spots on NOx formation.

[0083] The lack of component field information means that the spatial distribution of key reactive free radicals such as OH and NH is completely unavailable, and the local concentrations of stable components such as H2 and NH3 cannot be accurately measured. This means that the regions of chemical reactions cannot be directly observed, it is impossible to understand how fuel pyrolysis products affect the combustion reaction pathway, and it is even more impossible to assess the detailed chemical kinetic mechanisms of pollutant formation (such as NOx) during combustion.

[0084] Flame morphology and stability: The macroscopic morphology of the flame can only be observed through limited static images or visual observation. It is impossible to capture the dynamic characteristics of the flame, such as transient pulsation, propagation speed, and extinction process, and it is even more impossible to connect the flame dynamics with the deeper reasons of flow field and chemical reaction.

[0085] Data correlation and analysis: Due to the limited data types and lack of synchronization, existing systems cannot perform deep correlation analysis of multiple parameters, making it difficult to reveal the complex coupling mechanisms between activation parameters, flow fields, chemical reactions, and pollutant generation. They also lack machine learning capabilities, hindering pattern recognition and predictive optimization.

[0086] Performance comparison table: The table below compares the significant differences between the activated ammonia burner testing system of this invention and the existing "black box" testing system in terms of core diagnostic capabilities and optimization efficiency. All data are typical values ​​to quantify the superiority of this invention.

[0087] Table 1 compares the test system of the activated ammonia burner of this invention with the existing "black box" test system.

[0088] As can be seen from the above comparison, the activated ammonia burner testing system 100 provided by this invention has achieved revolutionary improvements over existing technology systems in terms of monitoring accuracy, real-time performance, diagnostic dimensions, spatial / temporal resolution, and data analysis depth. This "white-box" diagnostic capability frees researchers from the predicament of "knowing what but not why," enabling them to deeply understand the essential mechanism of the activated ammonia combustion process. This allows for efficient and precise burner design optimization based on scientific data, significantly accelerating the industrialization of high-performance, low-emission activated ammonia combustion technology.

[0089] In this embodiment, the burner can be of various types, including a gas burner testing system and a burner that ignites solid particulate matter using multiple gas burners. In one feasible embodiment, the burner is a multi-dimensional adjustable burner 20. The function of the multi-dimensional adjustable burner 20 is to ignite pulverized coal by activating ammonia combustion, thereby enabling the pulverized coal to burn explosively without producing coking.

[0090] like Figure 9 As shown, the multi-dimensional adjustable burner 20 in this embodiment includes a burner body 21 and a diffuser shroud 22 installed on one side of the flame tongue of the burner body 21. Figure 10As shown, the burner body 21 has multiple pipes inside. Near the outer edge of the burner body is a first gas pipe 211, which outputs a mixture of activated ammonia and oxygen. A second gas pipe 213 is located at the axial position of the burner body 21. The second gas pipe 213 is an independent pipe that outputs the mixture of activated ammonia and oxygen. A flame cap 214 is located at the end of the second gas pipe 213, and the flame cap 214 has multiple radially extending or obliquely upward branching output channels extending towards the opening of the diffuser shroud 22. A third pipe 212 is located in the area between the first gas pipe 211 and the second gas pipe 213. The function of the third pipe 212 is to output the desired fuel, such as gaseous fuel, unactivated ammonia, pulverized coal, atomized liquid, etc. In this embodiment, both the first gas pipe 211 and the third gas pipe 212 are arranged in a ring array.

[0091] One of the main purposes of using this multi-dimensional adjustable burner 20 is that, after the flame generated by the first gas pipe 211 is ignited, a flame shielding ring is formed. After the expected fuel is output from the third pipe 212, the flame output from the second gas pipe 213 is pressed by the flame pressure against the flame generated by the first gas pipe 211 to form a flame shielding ring. Through the above-mentioned multi-dimensional adjustable burner 20 and the test system 100 for the activated ammonia burner, comprehensive, real-time and high-precision monitoring of key parameters of the entire process of activated ammonia and added fuel combustion can be achieved.

[0092] Furthermore, preferably, an opening is made at the axial center of the burner body 21, and the second gas pipe 213 is a separate pipe. The second gas pipe 213 is assembled to the axial opening of the burner body 21, and can be controlled to move back and forth a certain distance to change the position of the burner cap 214, thereby adjusting the pressure and area of ​​fuel pressing against the flame shield. By changing the speed and pressure of the output material from the first gas pipe 211, the second gas pipe 213, and the third pipe 212, diverse tests can be performed very conveniently. The burner cap 214 is detachably connected to the front of the third pipe 212 via a threaded connection. The detachable burner cap can use different branch output channel structures as needed, enabling this multi-dimensional adjustable burner 20 to achieve optimized test data for various parameters.

[0093] The above content is only a preferred embodiment of the present invention. For those skilled in the art, many changes can be made in the specific implementation and application scope based on the ideas of the present invention. As long as these changes do not depart from the concept of the present invention, they all fall within the protection scope of this patent.

Claims

1. A test system (100) for activating an ammonia burner, characterized in that, include: The burner test chamber (130) is used to install the activated ammonia burner to be tested and to provide a controlled combustion environment; An activation module (120) is disposed outside the burner test chamber (130) and is used to pre-activate the ammonia fuel. The gas supply unit (110) has its output connected to the activation module (120) or the burner test chamber (130) for precise metering, mixing and delivery of ammonia fuel and oxidant; An optical diagnostic system (140) is installed at the corresponding window outside the burner test chamber (130) for non-invasive monitoring of the flow field, temperature field, component field and flame morphology inside the burner. Thermodynamic monitoring unit (150) includes sensors installed in the burner test chamber (130) for real-time acquisition of temperature and pressure information of the burner interior and surrounding environment; An exhaust monitoring unit (160) with its sensor located at the top exhaust port of the burner test chamber is used to quantitatively analyze the pollutant components in the combustion products; as well as The control system (170), electrically connected to the gas supply unit (110), activation module (120), optical diagnostic system (140), thermodynamic monitoring unit (150) and exhaust monitoring unit (160), is used to integrate, synchronize and analyze data from all sensors and diagnostic devices, and to precisely control the entire testing process.

2. The test system (100) for activating ammonia burners according to claim 1, characterized in that, The gas supply unit (110) includes multiple high-precision mass flow controllers (111), multiple pressure regulating valves (112), a gas mixer (113), and a fuel preheater (114). The high-precision mass flow controller (111) is installed in the gas input pipeline and is used to independently control the mass flow rates of ammonia, hydrogen, air and optional oxygen. The pressure regulating valve (112) is installed in the pipeline between the gas mixer (113) and the activation module (120) or the burner test chamber (130) to stabilize the pressure of each gas at a preset value. The gas mixer (113) is located at the end of the gas input pipe and has a static mixing structure or a vortex dynamic mixing chamber to ensure that multiple gases are uniformly mixed before entering the activation module (120) or the burner test chamber (130). The fuel preheater (114) is an electric heating preheater, which integrates a temperature sensor and a PID controller.

3. The test system (100) for activating ammonia burners according to claim 1, characterized in that, The activation module (120) is configured to be interchangeable or combined according to the activation method, and includes at least one catalytic pre-pyrolysis unit (121) or one plasma activation unit (122).

4. The test system (100) for activating ammonia burners according to claim 3, characterized in that, The catalytic pre-cracking unit (121) includes a tubular or plate reactor. The main material of the catalytic pre-cracking unit (121) is quartz glass or Inconel 625 high-temperature alloy. It is filled with a noble metal-based catalyst, which is supported on a high specific surface area carrier. The reactor is wrapped with electric heating wires and insulation materials, and integrates multiple thermocouples for monitoring the temperature distribution inside the reactor. The catalytic pre-pyrolysis unit (121) is equipped with an online gas sampling port. The sampling port uses a heated sampling probe, which is connected to a gas chromatograph or a tunable semiconductor laser absorption spectroscopy system via a heated pipeline to analyze the molar ratio of ammonia, hydrogen and nitrogen and other intermediate product components in the pre-pyrolysis products in real time. The gas chromatograph is equipped with a thermal conductivity detector or a flame ionization detector.

5. The test system (100) for activating ammonia burners according to claim 3, characterized in that, The plasma activation unit (122) includes a dielectric barrier discharge plasma generator or a microwave plasma generator, the electrode material of which is stainless steel or alumina ceramic, and the dielectric material is high-purity quartz or alumina ceramic. The generator is powered by a high-frequency high-voltage power supply or a microwave power supply. The generator is also equipped with a high-voltage probe and a current probe to measure the voltage and current waveforms of plasma discharge and to calculate the plasma dissipation power by the Lissajous figure method or the direct integration method. An optical window is provided at the outlet of the plasma generator. The plasma generator is connected to a fiber optic spectrometer for emission spectral diagnosis to identify and quantify the active free radicals present in the plasma and their relative concentrations.

6. The test system (100) for activating ammonia burners according to claim 1, characterized in that, The burner test chamber (130) is a double-layer water-cooled or air-cooled stainless steel structure, lined with high-temperature resistant ceramic material to ensure that the temperature of the chamber wall is controllable and the test environment is stable. The cavity wall is symmetrically provided with at least four sets of optical access windows (131) along the optical path direction. These windows are made of high-purity synthetic quartz or sapphire, with an optical transmittance of more than 95% in the ultraviolet to near-infrared band. They are designed in a conical shape and integrated with a purge gas interface to reduce wall effect and optical distortion. The cavity is designed with an adjustable burner mounting flange (132), which allows for fine adjustment of the burner in three dimensions and three angles. A multi-channel pressure sensor (133) is configured on the top or side of the cavity. The pressure sensor is piezoelectric or strain gauge designed to capture combustion instability events.

7. The test system (100) for activating ammonia burners according to claim 6, characterized in that, The burner mounting flange (132) includes a flange (1321), three linear motion pairs (1322), a sleeve (1323), a ventilation line (1324), three folding arms (1325), multiple locking screws (1326), a sleeve clamp (1327), and a composite corrugated cover (1328). The flange (1321) is installed at the end of the activation module (120) and is used to seal the internal cavity of the activation module (120); The three linear motion pairs (1322) are mounted on the end face of the flange (1321). The linear motion pairs (1322) have linear motion terminals and serve as power devices for adjusting the position and angle of the burner. One end of each of the three folding arms (1325) is hinged to the linear motion terminal of each of the three linear motion pairs (1322), and the other end of each of the three folding arms (1325) is hinged to the outer periphery of the sleeve clamp (1327), which serves to form a support for the sleeve clamp (1327) and a transmission component. The locking screw (1326) is installed at the connection of the branch folding arm of the folding arm and is used to pre-adjust the folding angle of the folding arm (1325) according to the preset parameters, so as to limit the maximum operating range of the burner; The sleeve clamp (1327) is used to install the burner and to stably clamp the burner; The sleeve (1323) is installed between the activation module (120) and the burner test chamber (130); The composite corrugated cover (1328) is closed at the end opening of the sleeve (1323), and together with the sleeve (1323) forms a heat-insulating cavity between the activation module (120) and the burner test chamber (130); The ventilation pipe (1324) is installed on the sleeve (1323) to reduce the temperature of the insulation cavity by active ventilation and to prevent the gas from entering the insulation cavity and causing deflagration; The flange (1321) has a through hole (1329) for passing through the gas supply pipe that supplies gas to the burner.

8. The test system (100) for activating ammonia burners according to claim 1, characterized in that, The optical diagnostic system (140) includes: a particle image velocimetry system (141), a coherent anti-Stokes Raman scattering system (142) or a tunable semiconductor laser absorption spectroscopy temperature measurement system (143), a planar laser-induced fluorescence system (144), a Raman scattering system, and a high-speed flame imaging system (145).

9. The test system (100) for activating ammonia burners according to claim 8, characterized in that: The particle image velocimetry system (141) includes a dual-pulse Nd:YAG laser, a high-resolution sCMOS camera, and a synchronization controller. The dual-pulse Nd:YAG laser provides a single-pulse laser output with an energy of not less than 150 millijoules at a wavelength of 532 nanometers, a pulse width of less than 8 nanoseconds, and a pulse interval that is continuously adjustable from 0.5 microseconds to 1 millisecond. It is used to illuminate alumina or silica tracer particles with a particle size of 1 to 5 micrometers. The high-resolution sCMOS camera has an image resolution of not less than 2560x2160 pixels and a full-frame acquisition rate of not less than 15 Hz. The sCMOS camera is equipped with corresponding optical filters and objectives, and obtains the transient two-dimensional velocity vector field inside the burner through cross-correlation calculation. The coherent anti-Stokes Raman scattering system (142) or the tunable semiconductor laser absorption spectroscopy temperature measurement system (143) is used to accurately measure the transient temperature field inside the burner.

10. The test system (100) for activating ammonia burners according to claim 8, characterized in that: The planar laser-induced fluorescence system (144) includes a tunable pulsed ultraviolet laser and a high-speed camera equipped with an image intensifier. The output wavelength of the laser can be finely tuned to the specific absorption spectral line of the target free radical in the range of 280 nm to 340 nm. The laser output is shaped into a thin sheet beam that passes through the combustion region. The high-speed camera has a corresponding narrowband filter for capturing the laser-induced fluorescence signal of target free radicals such as OH, NO, and NH to provide a two-dimensional relative concentration distribution of the target free radicals. The Raman scattering system consists of a high-power continuous wave laser, a confocal optical path, and a high-sensitivity spectrometer, used to quantitatively measure the absolute concentrations of N2, O2, H2, NH3, H2O, CO2, and CO inside the burner; The high-speed flame imaging system (145) includes a high-speed visible light camera or infrared camera, used to record the transient morphology, propagation speed, stability boundary and quenching process of activated ammonia combustion flame, and to extract the geometric feature parameters of the flame and the combustion oscillation frequency through image analysis software; the high-speed flame imaging system also includes a flame chemiluminescence imaging system equipped with ICCD, used to record the chemiluminescence signals of specific excited-state intermediate products such as OH, CH, NH, etc., to reflect the distribution and intensity of the combustion reaction region.

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