Ejector Refrigerant Separator for Two-Phase Suction Control

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Solution Overview

Problem

Ejector refrigeration systems face inefficiencies in refrigerant quality distribution, leading to suboptimal compressor performance and evaporator heat transfer, particularly due to the lack of a two-phase mixture in the compressor suction and evaporator, which affects power consumption and heat transfer efficiency.

Innovation Solution

The system introduces a means to provide a 1-10% quality refrigerant to the heat absorption heat exchanger and 85-99% quality refrigerant to the compressor and suction line heat exchanger, utilizing a modified accumulator with strategically placed holes to entrain liquid into the gas flow, creating a two-phase mixture for improved refrigerant distribution and heat transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a separator is used to divide refrigerant into liquid and gas flows, then refrigerant distribution is improved, but the compressor receives insufficient two-phase mixture leading to reduced efficiency

Engineering Contradiction:
Improverefrigerant distributionVSAvoidcompressor efficiency
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The patent extracts only a portion of the liquid refrigerant from the separator and reintroduces it to the compressor suction line. This selective extraction allows the compressor to receive a two-phase mixture (85-99% vapor with 1-15% liquid), improving efficiency while maintaining proper refrigerant distribution to the evaporator

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a suction line heat exchanger as an intermediary component between the separator and compressor. This heat exchanger facilitates the reintroduction of liquid refrigerant to the suction line, creating the desired two-phase mixture without disrupting the separator's primary function

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If liquid refrigerant is introduced to the compressor suction, then two-phase mixture is created improving efficiency, but compressor reliability may be compromised

Engineering Contradiction:
Improvecompressor efficiencyVSAvoidcompressor reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent carefully controls the parameters of liquid introduction to the compressor suction line, maintaining liquid content within the specific range of 1-15% by mass flow rate. This parameter control ensures the compressor receives beneficial two-phase mixture while preventing excessive liquid that could cause mechanical damage

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies partial action by introducing only a small portion of liquid refrigerant (1-15% of total mass flow rate) to the compressor suction line. This partial introduction is sufficient to improve compressor efficiency through two-phase compression while avoiding the harmful effects of excessive liquid

Inventive Principle:
Principle #16Partial or excessive action

3Productivity

If evaporator receives high quality (vapor) refrigerant, then heat transfer efficiency is improved, but system capacity control becomes less precise

Engineering Contradiction:
Improveheat transfer efficiencyVSAvoidsystem capacity control
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The patent implements a feedback control system that monitors refrigerant quality and system operating conditions, dynamically adjusting the amount of liquid refrigerant reintroduced to the compressor suction line. This feedback mechanism maintains optimal evaporator performance while enabling precise system capacity control

Inventive Principle:
Principle #23Feedback

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 approach reduces compressor power requirements, enhances evaporator performance, and allows for precise control of system capacity, improving overall refrigeration efficiency and reliability by optimizing refrigerant quality and distribution.

Implementation Method 1

utilizing a modified accumulator with strategically placed holes to entrain liquid into the gas flow, creating a two-phase mixture

Methodology Applied
Scientific EffectEntrainment: Entrainment

Implementation Method 2

The primary refrigerant flow 103 enters the inlet 40 and then passes into a convergent section 104 of the motive nozzle 100. It then passes through a throat section 106 and an expansion (divergent) section 108 through an outlet 110 of the motive nozzle 100. The motive nozzle 100 accelerates the flow 103 and decreases the pressure of the flow.

Methodology Applied
Scientific EffectNozzle acceleration and pressure reduction: De Laval Nozzle

Implementation Method 3

The pressure reduction caused to the primary flow by the motive nozzle helps draw the secondary flow 112 into the outer member.

Methodology Applied
Scientific EffectPressure differential induced flow: Pressure Gradient

Implementation Method 4

The outer member also has a divergent section or diffuser 118 downstream of the elongate throat or mixing section 116. The resulting combined flow 120 is a liquid/vapor mixture and decelerates and recovers pressure in the diffuser 118

Methodology Applied
Scientific EffectDiffuser pressure recovery: Diffusion

Implementation Method 5

In the heat rejection heat exchanger, the refrigerant loses/rejects heat to a heat transfer fluid (e.g., fan-forced air or water or other liquid).

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 6

Within the evaporator 64, the refrigerant absorbs heat from a heat transfer fluid (e.g., from a fan- forced air flow or water or other liquid)

Methodology Applied
Scientific EffectHeat absorption: Heat Exchanger

Data Source

PatentEP2596304A2Ejector cycle refrigerant separator
Publication Date: 2013.05.29 CARRIER CORP

AI summary

A system has a compressor (22). A heat rejection heat exchanger (30) is coupled to the compressor to receive refrigerant compressed by the compressor. An ejector (38) has a primary inlet coupled with heat rejection heat exchanger to receive refrigerant, a secondary inlet, and an outlet. The system has a heat absorption heat exchanger (64). The system includes means (180) for providing at least of a 1-10% quality refrigerant to the heat absorption heat exchanger and an 85-99% quality refrigerant to at least one of the compressor and, if present, a suction line heat exchanger.