Indoor machine and air conditioner
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In ceiling-concealed indoor units, the non-uniform air velocity distribution across the heat exchanger due to mismatched widths between air outlets and the heat exchanger leads to increased pressure loss and noise, and the oblique arrangement of the heat exchanger exacerbates these issues by increasing the distance between air outlets and the heat exchanger, causing further inefficiencies and noise.
Innovation Solution
The indoor unit design includes guide portions with open side regions and specific shapes, such as arcs or inclined surfaces, to ensure uniform air velocity distribution by preventing air stagnation and vortex formation, thereby reducing pressure loss and noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the heat exchanger width is made larger than air outlet widths, then heat exchange capacity is improved, but air velocity distribution becomes non-uniform and pressure loss increases
Solution Approach 1:
The air outlet is divided into multiple separate outlets (first air outlet and second air outlet) positioned at different locations. Each outlet has corresponding guide portions that segment the air flow paths, allowing independent control of air velocity distribution to different regions of the heat exchanger, thereby achieving uniform distribution across the entire heat exchanger width.
Solution Approach 2:
Guide portions are introduced as intermediary structures between the air outlets and the heat exchanger. These guide portions actively direct and shape the air flow, ensuring uniform velocity distribution across the heat exchanger width while maintaining the larger heat exchanger area for improved heat exchange capacity.
2Volume of moving object
If the heat exchanger is arranged obliquely to reduce unit size, then device compactness is improved, but distance between air outlets and heat exchanger increases causing efficiency degradation and noise
Solution Approach 1:
The guide portions extend in the width direction (lateral dimension) rather than only in the depth direction. By providing guide portions at multiple air outlets positioned at different width locations, the design utilizes the width dimension to reduce the distance between air outlets and heat exchanger surfaces, improving air handling efficiency while maintaining compact overall unit size through oblique arrangement.
3Loss of energy
If diffusers are enlarged to reduce air passage expansion, then pressure loss is reduced, but air streams do not sufficiently spread along wall surfaces
Solution Approach 1:
The guide portions are designed with curved surfaces that guide air streams to spread smoothly along the wall surfaces of the air passages. The curved geometry of the guide portions facilitates gradual air flow expansion and adherence to wall surfaces, preventing flow separation and reducing pressure loss while ensuring sufficient air stream spreading.
4Manufacturing precision
If guides are added to diffusers to improve air spreading, then air distribution is improved, but pressure loss increases due to guide resistance
Solution Approach 1:
The guide portions are designed with curved surfaces that smoothly guide air flow, reducing flow separation and turbulence. The curved geometry minimizes flow resistance and pressure loss while effectively distributing air uniformly across the heat exchanger width, achieving both improved air distribution and reduced pressure loss.
5Productivity
If multiple spiral casings are placed adjacent to each other, then air handling capacity is improved, but turbulence and vortex formation occur in spaces between casings
Solution Approach 1:
The guide portions are designed to extract and control air streams from each spiral casing outlet independently. By providing dedicated guide portions for each air outlet, the design prevents air streams from adjacent spiral casings from mixing and forming vortices in the spaces between casings, thereby reducing turbulence-induced pressure loss while maintaining high air handling capacity.
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
An indoor unit according to the present invention includes: an air-sending portion, which includes a casing having a rectangular air outlet and accommodating an impeller including a plurality of blades; a heat exchanger, which is configured to exchange heat with gas sent from the air-sending portion; and a guide portion, which includes an upper guide defining a passage for the gas and being arranged between an upper edge portion of the air outlet and an upper end portion of the heat exchanger and a lower guide defining a passage for the gas and being arranged between a lower edge portion of the air outlet and a lower end portion of the heat exchanger, and is open at side regions of the guide portion.