Ejector, manufacturing method thereof, and ejector-type refrigeration cycle
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Solution Overview
Problem
Ejectors in refrigeration cycles face challenges in maintaining energy conversion efficiency across varying load conditions due to issues with guiding gas-liquid two-phase refrigerant into the nozzle passage, leading to decreased performance in both high and low load operations.
Innovation Solution
The introduction of a groove in the nozzle passage that creates a separation vortex, increasing the passage sectional area and promoting boiling, along with a swirl flow generator to manage refrigerant flow and pressure, ensures efficient energy conversion regardless of load changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the dimensions of the swirl space are set for high load operation, then the gas-liquid two phase refrigerant flows into the nozzle passage in high load operation, but the refrigerant cannot be decompression boiled in low load operation
Solution Approach 1:
The patent introduces a movable passage defining member that can adjust the passage cross-sectional area dynamically. This allows the ejector to adapt its internal geometry to different load conditions, enabling proper decompression boiling in both high and low load operations by changing the passage dimensions according to the refrigerant flow rate.
Solution Approach 2:
The patent changes the physical parameters of the ejector by making the passage defining member movable, allowing the passage cross-sectional area to vary. This parameter change enables the system to maintain optimal performance across different operating loads by adjusting the passage area to match the refrigerant flow conditions.
2Reliability
If the dimensions of the swirl space are set for low load operation, then the gas-liquid two phase refrigerant flows into the nozzle passage in low load operation, but the swirl speed increases excessively and excessive gas-phase refrigerant is generated in high load operation
Solution Approach 1:
The movable passage defining member enables dynamic adjustment of the passage cross-sectional area, allowing the system to optimize the balance between swirl speed and refrigerant flow volume for different load conditions. This prevents excessive gas-phase refrigerant generation in high load operation while maintaining proper two-phase flow in low load operation.
Solution Approach 2:
By making the passage cross-sectional area a variable parameter rather than fixed, the system can adjust the degree of decompression boiling to match the load conditions, preventing excessive gas-phase refrigerant generation while maintaining energy conversion efficiency.
3Device complexity
If a fixed shape refrigerant inflow passage and swirl space are used, then the ejector structure is simple, but the gas-liquid two phase refrigerant cannot be guided into the nozzle passage when load changes occur
Solution Approach 1:
The patent introduces a movable passage defining member that can adjust the passage geometry dynamically. This adds some complexity to the structure but enables proper guidance of gas-liquid two phase refrigerant into the nozzle passage under varying load conditions, achieving adaptability.
Solution Approach 2:
The movable passage defining member serves multiple functions: it adjusts the passage cross-sectional area, controls the swirl flow characteristics, and guides the refrigerant flow to the nozzle passage. This multi-functionality justifies the added structural complexity by providing load-adaptive performance.
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 enhances energy conversion efficiency by generating boiling cores that increase refrigerant flow speed, maintaining high efficiency across different operational loads without excessive pressure loss or blockage.
Implementation Method 1
The introduction of a groove in the nozzle passage that creates a separation vortex
Implementation Method 2
promoting boiling, along with a swirl flow generator to manage refrigerant flow and pressure
Implementation Method 3
a swirl flow generator to manage refrigerant flow and pressure
Implementation Method 4
a gas-liquid two phase refrigerant, in which a gas-phase refrigerant is concentrated around the swirl center
Implementation Method 5
The most-upstream portion serves as a nozzle passage that reduces a pressure of a high-pressure refrigerant
Implementation Method 6
converting pressure energy of the refrigerant into kinetic energy in the nozzle passage
Implementation Method 7
The most-downstream portion serves as a diffuser passage. The diffuser passage mixes the injection refrigerant and the suction refrigerant and increases the pressure of the mixed refrigerant
Data Source
AI summary
An ejector has a nozzle, a body, a passage defining member and a drive portion. The body has a refrigerant suction port and a pressure increasing portion. A nozzle passage is defined between an inner surface of the nozzle and an outer surface of the passage defining member and has a minimum sectional area portion, a tapered portion, and an expansion portion. The minimum sectional area portion has a smallest passage sectional area. The tapered portion is located upstream of the minimum sectional area portion in a refrigerant flow direction and has a passage sectional area decreasing toward the minimum sectional area portion gradually. The expansion portion is located downstream of the minimum sectional area portion in the refrigerant flow direction and has a passage sectional area increasing gradually. The passage defining member has a groove that is recessed to increase the passage sectional area of the nozzle passage.