Variable-Swirl Ejector for Load-Stable Refrigerant Energy Conversion

Solution Overview

Problem

Ejector-type refrigeration cycles face challenges in maintaining high energy conversion efficiency due to fluctuations in refrigerant flow rates, as the shape of the air column in the swirl space changes with load conditions, affecting the two-phase-separated state of the refrigerant flowing into the nozzle passage.

Innovation Solution

An ejector design with a swirl flow generation portion and an actuation device that adjusts the passage cross-sectional areas to maintain an appropriate two-phase-separated state, ensuring efficient energy conversion by adjusting the angular momentum and velocity of the refrigerant flowing into the swirl space.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the shape of the swirl space is optimized for high-load operation, then energy conversion efficiency is improved during high-load operation, but the refrigerant cannot be properly boiled during low-load operation due to insufficient swirl velocity

Engineering Contradiction:

Improveenergy conversion efficiencyVSAvoidadaptability to load fluctuations

Core Design Contradiction:

Loss of energyVSAdaptability or versatility

Solution Approach 1:

The patent applies the dynamics principle by making the swirl space shape changeable according to operating conditions. Specifically, the swirl space is configured with a variable geometry that can adjust its shape based on the refrigerant flow rate, allowing optimal performance across different load conditions. This is achieved through a movable wall or adjustable structure that modifies the swirl space dimensions to maintain appropriate swirl velocity and two-phase separation effectiveness regardless of whether the system operates at high or low load.

Inventive Principle:

Principle #15Dynamics

2Loss of energy

If the shape of the swirl space is optimized for low-load operation, then the refrigerant can be properly boiled during low-load operation, but pressure loss increases during high-load operation due to excessive air column radius

Engineering Contradiction:

Improveenergy conversion efficiencyVSAvoidpressure loss

Core Design Contradiction:

Loss of energyVSQuantity of substance

Solution Approach 1:

The patent applies the dynamics principle by making the swirl space shape changeable according to operating conditions. Specifically, the swirl space is configured with a variable geometry that can adjust its shape based on the refrigerant flow rate, allowing optimal performance across different load conditions. This is achieved through a movable wall or adjustable structure that modifies the swirl space dimensions to maintain appropriate swirl velocity and two-phase separation effectiveness regardless of whether the system operates at high or low load.

Inventive Principle:

Principle #15Dynamics

3Device complexity

If a fixed swirl space shape is used, then the device structure is simple, but the refrigerant cannot maintain an appropriate two-phase-separated state across varying load conditions

Engineering Contradiction:

Improveswirl space structureVSAvoidtwo-phase-separated state stability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent applies the dynamics principle by making the swirl space shape changeable according to operating conditions. Specifically, the swirl space is configured with a variable geometry that can adjust its shape based on the refrigerant flow rate, allowing optimal performance across different load conditions. This is achieved through a movable wall or adjustable structure that modifies the swirl space dimensions to maintain appropriate swirl velocity and two-phase separation effectiveness regardless of whether the system operates at high or low load.

Inventive Principle:

Principle #15Dynamics

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

The design achieves high energy conversion efficiency regardless of load fluctuations by maintaining an optimal two-phase-separated state, enhancing boiling and pressure increase efficiency in the nozzle passage.

Implementation Method 1

a nozzle passage decompressing the refrigerant

Methodology Applied

Scientific EffectDecompression: Depressurisation

Implementation Method 2

an ejector that draws a fluid by a drawing effect of a jetted fluid jetted at high velocity

Methodology Applied

Scientific EffectJet effect: Jet

Implementation Method 3

a swirl flow generation portion generating a swirl flow about a central axis of the nozzle in the refrigerant flowing into the nozzle

Methodology Applied

Scientific EffectSwirl flow: Vortex Ring

Implementation Method 4

a diffuser portion in which the jetted refrigerant and the drawn refrigerant are mixed, a pressure of the mixed refrigerant being increased in the diffuser passage

Methodology Applied

Scientific EffectDiffusion: Diffusion

Data Source

PatentUS10184704B2Ejector and ejector-type refrigeration cycle

Publication Date: 2019.01.22 DENSO CORP

AI summary

An ejector includes a nozzle, a swirl flow generation portion, a body including a refrigerant suction port and a diffuser portion, a passage forming member, and an actuation device moving the passage forming member. A nozzle passage is defined between the nozzle and the passage forming member. A smallest passage cross-sectional area portion is provided in the nozzle passage. A swirl space that has a shape of a revolution and is coaxial with the nozzle, and a refrigerant inflow passage through which the refrigerant flows into the swirl space are defined in the swirl flow generation portion. The ejector further includes an area adjustment device that changes the passage cross-sectional area of the refrigerant inflow passage. According to this, an efficiency of energy conversion in the nozzle passage can be improved.