System Retrofit Background:

With the continuous tightening of global environmental standards for nitrogen oxide emissions, most regions have now explicitly stipulated that nitrogen oxide emissions from boilers must be below 50 mg/m³. In areas with stricter environmental regulations, emission limits have been further reduced to below 30 mg/m³. In this context, whether it is the configuration of low-NOx burners for new boilers or the retrofitting of existing thermal oil boilers with low-NOx technology, these measures have become essential technical solutions to ensure compliance with environmental regulations.

System Retrofit Scope:

- Low-nitrogen burner retrofit and control system upgrade

- On-site commissioning services and training

AURA System Retrofit Services:

Engineering Design

Equipment Manufacturing and Assembly

Control System Joint Commissioning

Factory Inspection and Testing

Packaging and Transportation

On-site Commissioning

Installation Guidance

Trial Run Guidance

Operating and Maintenance Training

Pros of the AURA Project Retrofit:

System Compatibility and Stability:

Retains the original brand burner to avoid structural and compatibility risks associated with replacing core components, while upgrading ancillary facilities to ensure seamless system integration and enhanced overall reliability.

Precise Independent Control Capability:

Relying on the burner management system, it achieves independent control of fuel, gas, and air control valves, optimizes the air-fuel ratio in real time based on load changes, replaces traditional mechanical linkage mechanisms, and significantly improves combustion efficiency and response accuracy.

Multi-dimensional coordinated control:

Integrates exhaust gas composition (oxygen content) with boiler temperature control logic: fuel valve opening responds to temperature requirements, and air valve opening dynamically matches oxygen content to achieve dual objectives of maximum energy efficiency and emission compliance.

Harsh Environment Adaptation:

For harsh environments, temperature and humidity sensors and heaters are installed within the control system cabinet to monitor and regulate environmental conditions. These protective devices are integrated into the cabinet, ensuring high system integration. This enhances system reliability in complex environments, reduces the risk of failures, and facilitates maintenance and repairs.

Safe and Convenient Installation:

The replacement burners are designed with installation dimensions that seamlessly match the original boiler, eliminating the need to modify the boiler's front cover. This ensures the boiler's structural integrity and safety, simplifies the installation process, shortens the renovation timeline, and reduces costs.

Quality and Safety Certification:

The burners and all associated components are certified by third-party inspection agencies such as BV and DNV, ensuring compliance with international standards and providing reliable assurance of quality and safety.

Low-NOx Burners Applications:

In response to environmental protection policies and customer requirements, AURA provides two main types of low-NOx burners for industry applications:

Flue Gas Recirculation Burners:

Part of the flue gas generated during combustion is reintroduced into the burner from the flue, where it is thoroughly mixed with fresh air and fuel before being burned again. The introduction of flue gas reduces the oxygen concentration and combustion temperature in the combustion zone, directly weakening the conditions for NOx formation. Additionally, components such as carbon dioxide and water vapor in the flue gas have high specific heat capacities, enabling them to absorb heat generated during combustion and further suppress NOx formation.

Surface Combustion Burners:

Fuel (such as natural gas or coal gas) is pre-mixed with air inside the burner to form a uniform pre-mixed gas. This pre-mixing process can be achieved using specialized mixing devices to ensure that fuel and air are mixed in a specific ratio, providing conditions for stable combustion.

The pre-mixed gas undergoes stable combustion across the porous medium surface of the burner. The porous medium, with its excellent permeability and structural characteristics, facilitates uniform diffusion and distribution of the pre-mixed gas across its surface. When the premixed gas encounters a heat source or reaches the ignition temperature, a uniform and dense thin flame layer forms on the surface of the porous medium. This combustion method ensures more uniform and stable combustion while effectively reducing peak combustion temperatures, thereby suppressing the generation of pollutants such as nitrogen oxides at the source and achieving dual optimization of clean combustion and high efficiency.

Pros of low-NOx burners:

Significant Environmental Protection and Emission Reduction Effects:

(1) Ultra-low NOx emissions: By combining technologies such as staged combustion, flue gas recirculation, and premixed combustion, nitrogen oxide emissions are reduced to below 30-50 mg/m³, meeting stringent environmental standards.

(2) Synergistic control of multiple pollutants: Simultaneously reduces emissions of CO, unburned hydrocarbons, and other pollutants, improves combustion completeness, and reduces the risk of secondary pollution.

Enhanced Combustion Efficiency and Energy Savings:

(1) Optimized thermal efficiency: Pre-mix combustion technology ensures uniform air/fuel mixing, resulting in higher combustion efficiency.

(2) Wide fuel adaptability: The intelligent control system is compatible with multiple fuels such as natural gas, biogas, and heavy oil, adapting to complex operating conditions.

(3) Increased waste heat recovery: Low-temperature combustion characteristics improve the utilization efficiency of waste heat in the flue gas duct, enhancing the overall energy efficiency of the system.

Outstanding Operational Stability and Economic Performance

(1) Strong flame stability: Technologies such as porous medium combustion and swirl flame stabilization ensure controllable combustion intensity in low-oxygen environments, preventing flameout or detonation risks.

(2) Low maintenance costs: Modular design reduces failure rates and lowers operational costs.

(3) Excellent retrofit compatibility: Existing boilers can be quickly upgraded by replacing the burner, with a short-retrofit cycle.

Intelligent Control and Safety Upgrades

(1) Dynamic regulation: An online monitoring system optimizes the air-fuel ratio in real time and controls emission fluctuations.

(2) Safety protection system: Integrated flame detection, pressure compensation, emergency shutdown, and other multiple protection measures.

(3) Digital interface: Supports IoT connectivity for remote monitoring and energy efficiency analysis, supporting smart factory construction.

Application Scope of Low-NOx Burners:

Pipe Network heating

Exhaust gas recovery incineration

Low-NOx emission retrofits