Staged Combustion Burner Segmentation for Maintenance Access
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Solution Overview
Problem
In staged combustion processes, maintaining and repairing fuel and primary oxidant injection components is challenging due to the need to manage NOx formation and ensure safe, minimally disruptive access without shutting down the combustion process, especially when preheated oxidants are used.
Innovation Solution
A staged combustion installation with a combustion chamber design that allows for separate injection of preheated secondary oxidant and primary oxidant, enabling maintenance on the primary oxidant injection unit without interrupting the combustion process, using a burner assembly with a primary and secondary injection unit configuration that allows access and continued operation with preheated secondary oxidant flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of repair
If the primary oxidant injection unit is accessed for maintenance in a conventional staged combustion burner, then the injectors can be maintained, but the combustion process must be shut down completely, causing production loss
Solution Approach 1:
The burner is divided into separate functional modules: a primary oxidant injection unit and a secondary oxidant injection unit, each with independent access paths. The primary oxidant injection unit can be accessed through a first access path while the secondary oxidant injection unit remains operational through a second access path, allowing maintenance without complete shutdown
Solution Approach 2:
The secondary oxidant injection unit acts as an intermediary that can maintain combustion functionality during maintenance of the primary oxidant injection unit. By switching to alternative access paths and using the secondary unit, the system maintains operational continuity while one module is being serviced
2Use of energy by moving object
If preheated secondary oxidant is used to improve combustion efficiency, then energy efficiency improves, but the risk of thermal damage to injection components increases
Solution Approach 1:
The oxidant injection system is segmented into primary and secondary pathways with independent temperature management. The preheated secondary oxidant flows through dedicated passages separated from the primary oxidant injection components, allowing thermal management without compromising overall system functionality
Solution Approach 2:
Thermal insulation and heat exchangers act as intermediaries between the preheated secondary oxidant and the injection components. These intermediaries transfer the necessary thermal energy while protecting the injection components from direct thermal damage, maintaining both efficiency and reliability
3Object-generated harmful factors
If staged combustion with preheated oxidant is implemented to control NOx formation, then emissions are reduced, but the system complexity increases
Solution Approach 1:
The combustion process is segmented into distinct stages with separate oxidant injection units for primary and secondary combustion. This segmentation allows independent control of combustion zones, enabling NOx reduction through staged oxidation while maintaining a manageable system structure through modular design
Solution Approach 2:
The burner assembly is designed with multi-functional components that serve multiple purposes: the same structural housing accommodates both primary and secondary oxidant injection units, and the refractory lining provides both thermal insulation and structural support, reducing overall system complexity despite the advanced combustion process
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables safe and minimally disruptive maintenance of primary oxidant injectors while maintaining heat and gas flow in the combustion zone, reducing the impact on the combustion process and NOx formation, and improving operational flexibility and efficiency.
Implementation Method 1
The secondary oxidant piping includes, upstream of the secondary oxidant inlet of the burner assembly, a heating device for heating the secondary oxidant which is supplied by the secondary oxidant source. The heating device is preferably adapted to heat a flow of secondary oxidant to a temperature of at least 100°C.
Implementation Method 2
The burner assembly comprises a primary passage extending from a primary inlet opening in the cold face to a primary outlet opening in the hot face. The burner assembly also comprises one or more secondary passages. Each secondary passage extends from a secondary inlet opening in the cold face to a secondary outlet opening in the hot face.
Implementation Method 3
The refractory wall has a hot face on the side of the combustion zone and a cold face on the opposite side, i.e. on the side facing away from the combustion zone.
Data Source
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AI summary
Installation for the staged combustion of fuel with a primary oxidant and a preheated secondary oxidant, whereby the fuel and the primary oxidant are injected into the combustion zone by means of a primary burner (9) located in a primary passage of a burner block (1) and whereby the secondary oxidant is injected into the combustion zone by means of at least two secondary oxidant injectors (5) which are located in one or more secondary passages of said burner block, whereby the primary burner (9) is part of a metallic primary injection unit (30) and whereby the at least two secondary oxidant injectors (5) are part of a separate metallic secondary injection unit (40), the primary injection unit (30) being attached to the cold face (16) of said burner block on one side of a horizontal plane (2) and the secondary injection unit (40) being attached to the cold face on the other side of the horizontal plane (2) so that the primary burner (9) or parts thereof can be removed from the primary passage and can be inserted into the primary passage via the inlet opening (8) of the primary passage on the one side of the horizontal plane (2) without accessing the other side of the horizontal plane (2).