Core-in-Shell Heat Exchanger Drains for Equal Refrigerant Levels

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Solution Overview

Problem

The single drain configuration in core-in-shell heat exchangers with baffles leads to unequal refrigerant levels, causing inefficient heat exchange and mechanical integrity issues due to pressure gradients and gas ingestion, which affects the thermal performance and lifespan of the heat exchanger.

Innovation Solution

Implementing a plurality of drains positioned at different heights on opposite sides of baffles within the heat exchanger shell, each connected to a drain pipe that protrudes from the bottom and couples to an outlet drain line, to equalize shell-side liquid levels and reduce hydraulic pressure drops.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If baffles are installed to reduce sloshing of shell-side liquid, then liquid stability is improved, but liquid level becomes unequal across different cores causing heat exchange efficiency to deteriorate

Engineering Contradiction:
Improveliquid stabilityVSAvoidheat exchange efficiency
Core Design Contradiction:
Stability of the object's compositionVSProductivity

Solution Approach 1:

The patent divides the single drain function into multiple drains positioned at different locations (e.g., opposite sides of baffles) within the shell. This segmentation allows each drain to serve a specific core region, equalizing liquid levels across all cores while maintaining the slosh-reducing effect of baffles, thus resolving the contradiction between liquid stability and heat exchange efficiency

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements local quality by positioning drains at specific locations corresponding to different core regions. Each drain is strategically placed to address the liquid level needs of adjacent cores, creating localized liquid level control that ensures uniform heat exchange conditions across all cores while preserving the overall liquid stability provided by baffles

Inventive Principle:
Principle #3Local quality

2Object-affected harmful factors

If baffles create pressure gradient to suppress liquid motion, then liquid sloshing is reduced, but gas ingestion increases due to low liquid levels

Engineering Contradiction:
Improveliquid sloshingVSAvoidgas ingestion
Core Design Contradiction:
Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The patent segments the drainage function into multiple drains positioned at optimal locations, ensuring that each drain maintains adequate liquid level in its vicinity. This prevents gas ingestion at any single location while preserving the pressure gradient effect of baffles for slosh suppression

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The multiple drains act as intermediaries between the baffle-induced pressure gradient and the shell-side liquid. They mediate the liquid level distribution to ensure adequate levels are maintained at all locations, preventing gas ingestion while allowing the baffles to continue suppressing liquid sloshing through pressure gradients

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If single drain configuration is used, then device complexity is low, but thermal performance deteriorates due to unequal refrigerant levels

Engineering Contradiction:
Improvedrain configuration complexityVSAvoidthermal performance
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent segments the single drain into multiple drains positioned at different locations within the shell. This segmentation enables equalization of refrigerant levels across all cores, significantly improving thermal performance. The increase in complexity is minimal (adding a few drains and connections) compared to the substantial gain in heat exchange efficiency

Inventive Principle:
Principle #1Segmentation

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 arrangement maintains consistent refrigerant levels, enhances heat exchange efficiency, reduces thermally induced fatigue, and prevents gas ingestion, thereby improving the operational reliability and longevity of the heat exchanger.

Implementation Method 1

cooling a natural gas stream through indirect heat exchange with one or more refrigerants

Methodology Applied
Scientific EffectHeat conduction: Conduction (thermal)

Implementation Method 2

efficient heat exchange, in the form of boiling of the refrigerant

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 3

efficient heat exchange, in the form of boiling of the refrigerant

Methodology Applied
Scientific EffectBoiling: Boiling

Implementation Method 4

expanding the cooled natural gas stream to near atmospheric pressure

Methodology Applied
Scientific EffectPressure drop: Pressure Drop

Data Source

PatentEP3137828B1Liquid drains in core-in-shell heat exchanger
Publication Date: 2018.10.10 CONOCOPHILLIPS CO
  • EP3137828B1 patent drawingFigure 1
  • EP3137828B1 patent drawingFigure 2
  • EP3137828B1 patent drawingFigure 3

AI summary

A core-in-shell heat exchanger, a method of fabricating the core-in-shell heat exchanger, and a method of exchanging heat in a core-in-shell heat exchanger disposed on a slosh-inducing moving platform are described. The method of exchanging heat includes introducing a shell-side fluid into a shell of the core-in-shell heat exchanger and introducing a fluid to be cooled into each of one or more cores of the core-in-shell heat exchanger, the one or more cores being arranged along an axial length of the shell with a plurality of baffles disposed on either side of the one or more cores along the axial length of the shell to reduce slosh of the shell-side fluid. The method also includes draining excess shell-side fluid using a plurality of drains, at least two of the plurality of drains being disposed on opposite sides of one of the plurality of baffles.