Refrigerant Distributing Device Nozzle Design

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Solution Overview

Problem

Conventional refrigerant distributing tubes in heat exchangers face issues with non-uniform refrigerant distribution due to gas-liquid separation and pressure imbalances, making it difficult to maintain uniform flow rates and clean the tubes effectively.

Innovation Solution

The refrigerant distributing device features a distributing tube with a series of nozzles along its length, each with a through hole that enhances mixing of gaseous and liquid refrigerants, increasing the refrigerant distribution pressure difference and flow rate uniformity, and optimizing the nozzle design to balance pressure drops across the tube.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional distributing tube with openings is used, then refrigerant distribution is attempted, but gas-liquid separation occurs due to density difference, affecting distribution uniformity

Engineering Contradiction:
Improverefrigerant distribution uniformityVSAvoidgas-liquid mixture stability
Core Design Contradiction:
Manufacturing precisionVSStability of the object's composition

Solution Approach 1:

A spiral groove is introduced as an intermediary element within the distributing tube. This spiral groove acts as a mediator that forces the refrigerant flow to rotate, creating a centrifugal effect that prevents gas-liquid separation while the refrigerant passes through the tube, thereby maintaining mixture stability and distribution uniformity

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The spiral groove structure induces rotational motion and turbulence in the refrigerant flow, creating a dynamic mixing effect that continuously prevents gas-liquid separation. The mechanical motion generated by the spiral groove keeps the two-phase flow homogeneous throughout the distributing tube

Inventive Principle:
Principle #18Mechanical vibration

2Manufacturing precision

If multiple openings are added to distributing tube, then refrigerant distribution coverage is improved, but pressure imbalance occurs between openings, causing flow rate imbalance

Engineering Contradiction:
Improverefrigerant distribution uniformityVSAvoidpressure balance between openings
Core Design Contradiction:
Manufacturing precisionVSStress or pressure

Solution Approach 1:

The spiral groove structure creates a rotational flow field that equalizes the pressure distribution among multiple openings. By inducing centrifugal force, the spiral groove ensures that pressure at different radial positions and along the tube length is balanced, preventing flow rate imbalance even when multiple openings are present

Inventive Principle:
Principle #12Equipotentiality

3Manufacturing precision

If complex opening patterns are used, then refrigerant distribution uniformity is improved, but machining difficulty increases due to increased amount and types of openings

Engineering Contradiction:
Improverefrigerant distribution uniformityVSAvoidmachining difficulty of openings
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The complex refrigerant distribution function is segmented into two parts: the spiral groove structure (which can be formed by simpler processes like rolling or extrusion) and the openings (which can be standardized). This segmentation allows the spiral groove to handle the complex flow control while openings remain simple features, reducing overall machining difficulty

Inventive Principle:
Principle #1Segmentation

4Manufacturing precision

If multiple openings are created in distributing tube, then refrigerant distribution is enhanced, but cleaning becomes difficult due to burrs on machining surfaces

Engineering Contradiction:
Improverefrigerant distribution uniformityVSAvoidcleaning ease of distributing tube
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

Instead of creating openings first and then dealing with burrs, the spiral groove is formed first (which has no burrs), and openings are then created within this smooth groove structure. This inverted sequence ensures that the spiral groove surfaces remain smooth and burr-free, making cleaning easier while still providing effective refrigerant distribution

Inventive Principle:
Principle #13The other way round (Inversion)

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 improves refrigerant distribution uniformity and heat exchange performance by maintaining consistent pressure differences between nozzles, reducing gas-liquid separation, and facilitating easier machining and cleaning.

Implementation Method 1

each nozzle 2 has a predetermined length and is formed with a through hole 21 communicating an interior of the distributing tube 1 and an exterior of the distributing tube, the gaseous refrigerant and the liquid refrigerant may be mixed again when flowing in the through holes 21 of the nozzles 2

Methodology Applied
Scientific EffectGas-liquid mixing: Turbulence

Implementation Method 2

Pressures at individual openings are not balanced in a refrigerant flow direction, thus causing flow rate imbalance between individual openings in a length direction of the distributing tube

Methodology Applied
Scientific EffectPressure drop: Pressure Drop

Data Source

PatentEP2650635B1Refrigerant distributing device and heat exchanger with the same
Publication Date: 2023.05.10 SANHUA(HANGZHOU) MICRO CHANNEL HEAT EXCHANGER CO LTD
  • EP2650635B1 patent drawingFigure 1~2
  • EP2650635B1 patent drawingFigure 3~4
  • EP2650635B1 patent drawingFigure 5~6

AI summary

A refrigerant distributing device and a heat exchanger comprising the refrigerant distributing device are provided. The refrigerant distributing device comprises a distributing tube (1) defining a first end and a second end in a length direction thereof, and a plurality of nozzles (2) disposed on the distributing tube (1) along the length direction of the distributing tube, each nozzle having a predetermined length and being formed with a through hole (21) communicating an interior of the distributing tube and an exterior of the distributing tube. By provision of the nozzles, the flow resistance is increased, the refrigerant flow rate is more uniform along the length direction of the distrusting tube. In addition, the refrigerant can be ejected along the radial direction, the axial direction, the circumferential direction and other directions, so that the uniformity of the refrigerant in the space outside the distributing tube is improved.