Blower housing for blower of HVAC system
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional blower housings in HVAC systems are inadequately designed to effectively block air recirculation, leading to reduced operational efficiency and scalability issues when adjusting for different rotor sizes.
Innovation Solution
The blower housing includes a cutoff plate with adjustable geometry and positioning based on reference features of the centrifugal fan, such as the position, dimensions, and geometry of the cutoff plate, to enhance air flow direction and reduce recirculation, allowing for scalable implementation across various HVAC applications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional blower housing design is used, then manufacturing simplicity is maintained, but air recirculation blocking effectiveness deteriorates
Solution Approach 1:
The blower housing is segmented into multiple functional components including a cutoff plate with specific geometry, a rotor assembly, and a housing structure with defined inlet/outlet passages. The cutoff plate is further segmented with a leading edge positioned at a specific radial distance from the rotor axis, creating distinct functional zones for air flow control and recirculation prevention.
Solution Approach 2:
The design incorporates dynamic air flow management through the rotating rotor blades that actively direct air flow, combined with the stationary cutoff plate that passively blocks recirculation paths. The interaction between the rotating rotor and stationary housing components creates dynamic control over air flow patterns to prevent recirculation.
2Productivity
If blower housing is designed for specific rotor size, then air flow efficiency is optimized, but adaptability to different rotor sizes deteriorates
Solution Approach 1:
The design uses dimensionless parameters and scaling relationships where the cutoff plate leading edge radial distance is defined as a proportion (4-20%) of the rotor outer blade boundary radial distance. This parametric approach allows the housing geometry to scale proportionally with different rotor sizes while maintaining optimal air flow efficiency and recirculation blocking effectiveness across various applications.
Solution Approach 2:
The blower housing design serves multiple functions simultaneously: it directs air flow across the heat exchanger, blocks recirculation paths, and accommodates various rotor sizes through proportional scaling. The cutoff plate geometry and positioning are designed to perform both air flow direction and recirculation prevention functions across a range of rotor configurations.
3Reliability
If cutoff plate is positioned closer to rotor, then recirculation blocking is improved, but risk of interference with rotor operation deteriorates
Solution Approach 1:
The cutoff plate is designed with non-uniform geometry where the leading edge is positioned at a specific radial distance (4-20% of rotor outer blade boundary radial distance) from the rotor axis, creating a localized blocking zone precisely where recirculation occurs without extending into the rotor operational space. The plate thickness and angular positioning are optimized to provide maximum blocking effectiveness at the critical recirculation interface while maintaining safe clearance from rotating blades.
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 improves the operational efficiency of the blower assembly by effectively directing air flow and maintaining efficiency across different sizes and configurations of centrifugal fans, facilitating universal implementation in various HVAC settings.
Implementation Method 1
A centrifugal fan includes a fan wheel and a rotational axis. A plurality of blades are coupled to the fan wheel at an inner blade boundary and extend radially outwardly from the fan wheel to an outer blade boundary.
Data Source
AI summary
A blower assembly for a heating, ventilation, and/or air conditioning (HVAC) system includes a centrifugal fan having a fan wheel. A plurality of blades are coupled to the fan wheel at an inner blade boundary and extend radially to an outer blade boundary. The blower assembly includes a first housing panel and a second housing panel disposed on opposite sides of the centrifugal fan and extending transverse to the centrifugal fan. The blower assembly includes a wall extending between the first housing panel and the second housing panel and a flange extending from the wall at a vertex. The flange extends outwardly from the wall. A first radial distance from the vertex to the outer blade boundary is between 4 percent and 20 percent of a second radial distance from a rotational axis of the centrifugal fan to the outer blade boundary.