Ejector Nozzle Positioning for Refrigeration Expansion Efficiency
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Solution Overview
Problem
Conventional refrigeration cycle apparatuses with ejectors face challenges in precise control of the nozzle's neck diameter, leading to inefficiencies due to expansion deficiencies or over-expansion under varying thermal loads, and existing solutions with moveable needles only control the nozzle diameter without addressing the low-pressure passage and nozzle-suction distance.
Innovation Solution
The ejector design includes a moveable nozzle and needle within the ejector body, allowing for control of the nozzle's sectional area and the low-pressure passage diameter, with a drive mechanism to adjust positions based on compression ratios, thereby optimizing the flow areas and preventing expansion deficiencies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the nozzle neck diameter is precisely controlled to several tens of microns, then the flow control precision is improved, but the fabrication difficulty and cost increase significantly
Solution Approach 1:
The patent applies the dynamics principle by making the nozzle moveable relative to the mixing chamber instead of being fixed. The nozzle can be adjusted to different positions along the flow direction, allowing the effective neck diameter and flow characteristics to be dynamically changed. This mechanical adjustment approach replaces the need for precise fabrication of multiple nozzles with different dimensions, as the same nozzle can be positioned to achieve different flow rates and expansion ratios.
Solution Approach 2:
The patent implements parameter changes by allowing the nozzle position to be varied, which changes the effective flow parameters including the neck diameter exposure and the distance to the mixing chamber inlet. This enables the system to adapt to different operating conditions (thermal loads, compression ratios) by adjusting geometric parameters mechanically rather than requiring precise fabrication of multiple components with different parameters.
2Adaptability or versatility
If a moveable needle is used to control the nozzle diameter, then the flow control flexibility is improved, but the device complexity increases as only the nozzle diameter can be controlled while the low pressure passage and nozzle-suction distance remain uncontrolled
Solution Approach 1:
The patent extends the dynamics principle by making both the nozzle and the low-pressure passage moveable. The nozzle can move relative to the mixing chamber, and the low-pressure passage can also move or be adjusted. This coordinated movement allows simultaneous control of multiple parameters (nozzle effective diameter, low-pressure passage diameter, and nozzle-to-suction distance) using a integrated mechanism, reducing overall system complexity compared to controlling each parameter separately.
Solution Approach 2:
The patent merges the control functions by combining the adjustment mechanisms for the nozzle and the low-pressure passage into a coordinated system. Both components can be adjusted together to maintain optimal geometric relationships, and the control mechanism is designed to manage multiple parameters simultaneously rather than requiring separate independent controls for each parameter.
3Device complexity
If the nozzle position is fixed, then the device simplicity is maintained, but the expansion efficiency decreases under varying thermal loads due to expansion deficiency or over-expansion
Solution Approach 1:
The patent applies dynamics by making the nozzle moveable relative to the mixing chamber, allowing the system to adapt to varying thermal loads and compression ratios. The nozzle can be positioned to achieve optimal expansion conditions for different operating scenarios, preventing both expansion deficiency and over-expansion. This dynamic adjustment capability maintains high expansion efficiency across a wide range of operating conditions while keeping the overall device structure relatively simple.
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 enhances the efficiency of the ejector by allowing precise control of the nozzle and needle positions, improving the refrigeration cycle's performance by preventing expansion deficiencies and reducing fabrication complexity and costs.
Implementation Method 1
a nozzle provided in the suction part so as to be moveable, and configured to inject a high pressure refrigerant
Implementation Method 2
having a mixing part or portion provided at one side of the suction part and configured to mix the high pressure refrigerant with the low pressure refrigerant
Implementation Method 3
a diffuser provided at one side of the mixing part and configured to increase a pressure of the low pressure refrigerant
Data Source
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AI summary
An ejector (200, 200a) and a refrigeration cycle apparatus having an ejector (200) are provided. The ejector (200) may include an ejector body (210) having a suction portion (212) into which a high pressure refrigerant and a low pressure refrigerant may be suctioned, and having a mixing portion (232) provided at one side of the suction portion (212) and configured to mix the high pressure refrigerant with the low pressure refrigerant; a nozzle (260) movably provided in the suction portion (212), and configured to inject the high pressure refrigerant; a needle (250) inserted into an end of the nozzle (260) and configured to control a flow sectional area of the nozzle (260); and a nozzle drive (290) configured to drive the nozzle (260) so as to be relatively movable with respect to the mixing portion (232) and the needle (250). As a flow sectional area of a high pressure refrigerant passage and a flow sectional area of a low pressure refrigerant passage are controlled, a driving efficiency of the ejector may be enhanced.