Integrated Separator and Distributor for Reduced Refrigerant Charge

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Solution Overview

Problem

Falling film evaporators in HVAC&R systems face challenges with significant refrigerant charge holdup due to separation volumes and liquid-filled distribution manifolds, leading to increased costs and greenhouse gas emissions.

Innovation Solution

The design incorporates a separator and distributor assembly with refrigerant gutters and sparge channels that receive separated liquid refrigerant, allowing it to flow through sparge openings and into a distribution manifold, optimizing refrigerant distribution and reducing the refrigerant charge by up to 15% compared to current systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separation volumes and liquid-filled distribution manifolds are used to meter liquid refrigerant, then reliable metering is achieved, but refrigerant charge holdup increases significantly

Engineering Contradiction:
Improvemetering reliabilityVSAvoidrefrigerant charge holdup
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent extracts the liquid refrigerant metering function from the traditional liquid-filled distribution manifold and relocates it to a separate separator assembly. The separator extracts and meters liquid refrigerant before it enters the distribution manifold, allowing the manifold to be smaller and hold less refrigerant while maintaining reliable metering through the separator's controlled discharge.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a separator as an intermediary component between the refrigerant inlet and the distribution manifold. This separator acts as a mediator that performs the liquid metering function, enabling the distribution manifold to be minimized in size and refrigerant charge while ensuring consistent liquid supply to the evaporator tubes.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Quantity of substance

If distribution manifold size is reduced to minimize refrigerant charge, then greenhouse gas emissions decrease, but liquid refrigerant distribution uniformity may be compromised

Engineering Contradiction:
Improverefrigerant chargeVSAvoidliquid distribution uniformity
Core Design Contradiction:
Quantity of substanceVSStability of the object's composition

Solution Approach 1:

The patent performs preliminary liquid refrigerant separation and metering in the separator assembly before the refrigerant enters the distribution manifold. By pre-metering the liquid refrigerant and controlling its discharge rate, the system ensures uniform distribution to the evaporator tubes even with a minimized distribution manifold size, maintaining distribution stability while reducing total refrigerant charge.

Inventive Principle:
Principle #10Preliminary action

3Quantity of substance

If spray-based distribution systems are used, then refrigerant charge is reduced, but distribution performance across wider operating conditions deteriorates

Engineering Contradiction:
Improverefrigerant chargeVSAvoidoperating condition range
Core Design Contradiction:
Quantity of substanceVSAdaptability or versatility

Solution Approach 1:

The patent employs hydraulic principles through the separator and sparge channel design to control liquid refrigerant flow. The sparge channels use hydrostatic pressure and controlled flow paths to meter liquid refrigerant, providing adaptability across wider operating conditions while maintaining reduced refrigerant charge levels, outperforming spray-based systems in terms of operating range versatility.

Inventive Principle:
Principle #29Pneumatics and hydraulics

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 ensures effective liquid refrigerant distribution across evaporator tubes with reduced refrigerant charge, maintaining near-ideal performance and tube wetting while minimizing the size of the distribution manifold, and provides superior distribution across a wider range of operating conditions compared to spray-based systems.

Implementation Method 1

separating a liquid refrigerant from the liquid and vapor refrigerant at the separation volume

Methodology Applied
Scientific EffectGravity separation: Gravitation

Implementation Method 2

separating a liquid refrigerant from the liquid and vapor refrigerant

Methodology Applied
Scientific EffectDensity difference separation: Density Gradient

Implementation Method 3

The liquid refrigerant is urged out of one or more sparge openings at a top of the sparge channel via refrigerant pressure in the separation volume

Methodology Applied
Scientific EffectPressure-driven flow: Pressure Gradient

Data Source

PatentEP3775722B1Integrated separator and distributor
Publication Date: 2024.01.03 CARRIER CORP
  • EP3775722B1 patent drawingFigure 1
  • EP3775722B1 patent drawingFigure 2
  • EP3775722B1 patent drawingFigure 3

AI summary

A separator and distributor assembly for a falling film evaporator housed within the evaporator shell includes a housing defining a separation volume, a refrigerant inlet configured to admit a liquid and vapor refrigerant flow into the separation volume and one or more refrigerant gutters extending along a lengthwise axis of the housing. The refrigerant gutter has a gutter inlet at a bottom of the separation volume, and the one or more refrigerant gutters are configured to receive separated liquid refrigerant from the separation volume. One or more sparge channels are in fluid communication with the refrigerant gutters. The sparge channel includes one or more sparge openings at a top of the sparge channel vertically below the gutter inlet. The one or more sparge openings are configured to flow liquid refrigerant therefrom.