Method for reducing the impact of motion in a core-in-shell heat exchanger

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Solution Overview

Problem

Sloshing of vaporizing fluid in core-in-shell heat exchangers leads to instability and reduced thermal performance, affecting the stability and control of floating liquefaction vessels used for LNG production, as it impacts the cyclical behavior of heat transfer efficiency and production capacity.

Innovation Solution

A core-in-shell heat exchanger design with an external horizontal separator and vapor disengaging conductor pipes, including a vapor riser and upper vessel with slosh suppressing baffles, to manage the liquid and vapor mixture and minimize motion effects, enhancing the thermosiphon circulation and heat transfer efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If vaporizing fluid is allowed to slosh freely inside the shell of the heat exchanger, then the thermal function of the heat exchanger core is adversely affected, but adding motion restriction structures increases device complexity

Engineering Contradiction:
Improvethermal function stabilityVSAvoidheat exchanger structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The heat exchanger is divided into functional segments: a shell containing vaporizing fluid and a separate heat exchanger core with multiple channels. This segmentation allows the core to maintain stable thermal function while the shell accommodates fluid motion, resolving the contradiction between thermal stability and structural simplicity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The heat exchanger core acts as an intermediary structure between the shell and the process fluid. It provides stable thermal exchange surfaces while being isolated from the direct impact of vaporizing fluid sloshing, thus maintaining thermal function without requiring complex motion restriction structures.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Stability of the object's composition

If motion restriction structures are added to the heat exchanger, then the stability and control are improved, but the device complexity increases

Engineering Contradiction:
Improveheat exchanger stabilityVSAvoidheat exchanger structure
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

By separating the vaporizing fluid containment function (shell) from the heat exchange function (core), the design achieves stability without adding complex motion restriction structures. The segmented architecture allows each component to perform its function independently.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The heat exchanger core's channel structure naturally provides stability by maintaining fixed thermal exchange surfaces, while the shell accommodates fluid motion. The system achieves stability through its inherent structural design rather than additional active control mechanisms.

Inventive Principle:
Principle #25Self-service

3Productivity

If the heat exchanger is designed with multiple cores and shells, then the heat transfer efficiency is improved, but the manufacturing complexity increases

Engineering Contradiction:
Improveheat transfer efficiencyVSAvoidheat exchanger fabrication
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The heat exchanger employs multiple discrete cores, each with its own channel structure, allowing independent manufacturing and assembly. This modular segmentation enables efficient heat transfer through parallel processing while simplifying fabrication compared to a single complex integrated structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple cores are positioned within a single shell, creating a nested configuration where several heat exchange units share a common containment structure. This nesting approach increases heat transfer efficiency while reducing manufacturing complexity compared to building multiple separate heat exchangers.

Inventive Principle:
Principle #7Nested doll (Nesting)

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 solution effectively reduces the impact of motion, stabilizes the heat exchanger operation, and enhances the overall performance and production capacity by ensuring efficient disengagement of non-vaporized streams and maintaining optimal liquid levels, thereby improving the thermal and hydraulic performance.

Implementation Method 1

vaporizing fluid which is at or near its boiling point

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 2

heat exchanger core with a plurality of spaced apart cores within the shell

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 3

The plurality of spaced apart cores within the shell are completely submerged, i.e., flooded, in vaporizing fluid

Methodology Applied
Scientific EffectThermosiphon circulation: Thermosyphon

Data Source

PatentEP2795216B1Method for reducing the impact of motion in a core-in-shell heat exchanger
Publication Date: 2019.11.20 CONOCOPHILLIPS CO
  • EP2795216B1 patent drawingFigure 1~3

AI summary

Methods and apparatuses for reducing the effects of motion in a core-in-shell type heat exchager are provided. One method for reducing the impact of motion in a heat exchanger includes: (a) flooding the heat exchanger with a vaporizing fluid, wherein the heat exchanger includes an internal volume defined within a shell and a plurality of spaced apart cores disposed within the internal volume of the shell; (b) introducing a hot process feed stream to an upper vessel, wherein the upper vessel is located above the heat exchanger, wherein the upper vessel is connected to the heat exchanger via a plurality of conductor pipes.