Heat Shield Plate Airflow Structure for Low-Air Burner Cooling
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Solution Overview
Problem
Existing combustion apparatuses and water heaters face inefficiencies in cooling and protecting heat shield plates, as they require a significant amount of air for cooling, which can lead to increased fan size or revolutions, and result in heat damage to the shield plates and burner case.
Innovation Solution
The combustion apparatus incorporates a heat shield plate with a stepped portion and air passage holes, along with a facing wall portion that collides with upward airflow, creating an eddying current to efficiently cool the shield plates while minimizing air consumption, and a configuration that prevents flames from contacting the heat shield plates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If air is supplied through air passage holes in the heat shield plate to cool it, then the heat shield plate is cooled and protected from heat damage, but the amount of air consumed increases requiring larger fan size or more fan revolutions
Solution Approach 1:
The heat shield plate is divided into multiple sections with air passage holes located only in specific regions (the curved portion and flat portion facing the flame), rather than requiring cooling across the entire plate surface. This segmentation allows cooling to be focused where heat exposure is highest, reducing overall air consumption while maintaining effective temperature control.
Solution Approach 2:
Air passage holes are strategically positioned only in the curved portion and flat portion of the heat shield plate that are most exposed to flame and combustion gas. This local quality approach ensures that cooling resources are concentrated on the critical hot zones, achieving effective temperature control with minimized air consumption rather than uniformly cooling the entire plate.
2Temperature
If more air is supplied into the burner case to cool the heat shield plate, then cooling effectiveness improves, but the amount of air available for combustion decreases
Solution Approach 1:
The air supply system is segmented into separate pathways: one for combustion (through the burner) and another for cooling (through air passage holes in the heat shield plate). This segmentation allows independent control of combustion air and cooling air, ensuring that cooling air consumption does not reduce the air available for combustion, thereby maintaining combustion efficiency while achieving effective cooling.
Solution Approach 2:
The fan serves multiple functions simultaneously: it supplies air for combustion to the burner and separately supplies air for cooling through the air passage holes in the heat shield plate. This multi-functionality allows a single fan to handle both combustion and cooling requirements without compromising either function, resolving the contradiction between cooling effectiveness and combustion efficiency.
3Temperature
If air passage holes are provided in the heat shield plate for cooling, then the heat shield plate is protected from heat damage, but the structural integrity and strength of the plate may be compromised
Solution Approach 1:
Air passage holes are provided only in specific portions of the heat shield plate (the curved portion and flat portion) rather than throughout the entire plate structure. This segmentation maintains the structural integrity of the main plate body while allowing localized cooling where heat exposure is highest, thus protecting the plate from heat damage without significantly compromising overall strength.
Solution Approach 2:
The heat shield plate has different structural qualities in different regions: the main plate body maintains full structural strength, while only the curved and flat portions exposed to flame contain air passage holes. This local quality approach ensures that cooling functionality is provided where needed without weakening the overall structural integrity of the plate.
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
This design effectively reduces air consumption for cooling, prevents heat damage to the heat shield plates and burner case, and lowers operational costs by minimizing fan requirements.
Implementation Method 1
air passage holes are provided in the stepped portion to extend therethrough so as to allow air supplied from the fan and travelling from under the stepped portion to upwardly pass the air passage holes
Implementation Method 2
The main plate portion is provided with a facing wall portion which protrudes from a middle part of the main plate portion in the vertical height direction thereof toward the flame formation region and faces the air passage holes so as to be subjected to a collision with air travelling upward from the air passage holes
Implementation Method 3
heat shield plate including a main plate portion located on a lateral side of a flame formation region above the burner to erect in a vertical height direction
Data Source
AI summary
A combustion apparatus includes a burner and a heat shield plate. The heat shield plate includes a main plate portion located on a lateral side of a flame formation region above the burner to erect, a stepped portion protruding from a lower end of the main plate portion toward the burner and set at approximately the same height as that of a flame hole surface of the burner, and air passage holes provided in the stepped portion. The main plate portion is provided with a facing wall portion which protrudes from a middle part of the main plate portion in a vertical height direction thereof toward the flame formation region and faces the air passage holes so as to be subjected to a collision with air travelling upward from the air passage holes. This configuration allows the heat shield plate to be properly cooled/protected, while reducing consumed air.