Ejector
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Solution Overview
Problem
The existing ejector designs for vapor-compression refrigeration cycles face instability in energy conversion efficiency due to inclination of the passage formation member's center axis, leading to uneven pressure distribution and increased mixing losses, especially when handling refrigerants with different physical properties.
Innovation Solution
The ejector design incorporates a passage formation member supported by upstream and downstream actuating bars, ensuring the center axis remains coaxial, and includes throat portions that direct the refrigerant flow to promote boiling and stabilize the gas column, reducing mixing losses by adjusting the nozzle and diffuser passage areas based on load variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the passage formation member is displaced according to load variation, then the ejector can operate appropriately with changing conditions, but the center axis of the passage formation member becomes inclined from the center axis of the swirling space
Solution Approach 1:
The patent introduces actuating bars as intermediary components between the drive mechanism and the passage formation member. These actuating bars transmit the displacement motion while maintaining the coaxial alignment through their structural design, preventing direct inclination of the passage formation member during load variation adjustments.
Solution Approach 2:
The patent changes the geometric parameters of the actuating bars and their connection points to the passage formation member. By carefully designing the length, position, and orientation of these bars, the system allows axial displacement while constraining radial deviation, thus maintaining alignment stability during adaptability adjustments.
2Adaptability or versatility
If the center axis of the passage formation member is inclined, then the passage cross-sectional area varies in circumferential direction, but the energy conversion efficiency in the nozzle passage is lowered
Solution Approach 1:
The actuating bars serve as intermediaries that decouple the displacement function from the alignment function. They allow the passage area to be adjusted for adaptability while preventing the inclination that would cause energy losses, thus resolving the contradiction between adjustability and efficiency.
3Ease of operation
If multiple actuating bars are used to couple the passage formation member to the drive mechanism, then the passage formation member can be displaced, but the center axis becomes inclined in some cases
Solution Approach 1:
The patent optimizes the geometric parameters of the actuating bars including their lengths, attachment positions, and angles. By carefully selecting these parameters, the system achieves ease of displacement operation while maintaining axis alignment stability through the coordinated motion of multiple bars.
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 configuration stabilizes high energy conversion efficiency across varying loads and refrigerant properties, reducing mixing losses and maintaining efficient operation by preventing axis inclination and promoting consistent boiling within the nozzle passage.
Implementation Method 1
a refrigerant passage having an annular cross section is provided between an inner surface of the body and a conical lateral surface of the passage formation member. A portion of the refrigerant passage on a most upstream side in a refrigerant flow is used as a nozzle passage
Implementation Method 2
a refrigerant that flows out of an evaporator through a refrigerant suction port provided in a body is drawn by a suction action of supersonic jet refrigerant jetted from a nozzle passage
Implementation Method 3
in a diffuser passage, a mixture refrigerant of the jet refrigerant and a suction refrigerant is raised in pressure
Implementation Method 4
a swirling space is provided in the body of the ejector to swirl the refrigerant flowing into the nozzle passage around a center axis of the passage formation member. In the swirling space, a liquid-phase refrigerant flowing out of a radiator is swirled so that the refrigerant on a swirling center side is reduced in pressure and boiled
Implementation Method 5
a drive mechanism that displaces the passage formation member to change a passage cross-sectional area of the refrigerant passage
Data Source
AI summary
An ejector includes a body including an inflow space into which a refrigerant flows, a passage formation member disposed inside the body and having a conical shape, and a nozzle passage having an annular cross section functioning as a nozzle and a diffuser passage having an annular cross section functioning as a pressurizing portion between an inner wall surface of the body and a conical lateral surface of the passage formation member. A drive mechanism that displaces the passage formation member along a center axis is coupled to an upstream actuating bar which extends from the passage formation member toward the inflow space and is slidably supported by the body. A largest outer diameter portion of an annular member forming a wall surface of the nozzle passage provides a throat portion functioning as an edge for enlarging a passage cross-sectional area to cause a separation vortex in the refrigerant.