Pulse combustion heat exchanger system

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Solution Overview

Problem

Pulse combustion heat exchangers face challenges in maintaining structural integrity and minimizing thermal stress at elevated temperatures, while achieving efficient heat transfer and reducing maintenance needs in industrial processes.

Innovation Solution

The design incorporates an aerovalve with conical surfaces and resonance conduits within the combustion section, allowing for efficient mixing and combustion of oxidant and fuel, which generates a pulsating combustion stream that transfers heat effectively through resonance conduits to a heat transfer medium, while the aerovalve acts as a fluidic diode to self-aspirate oxidant and fuel, maintaining a self-sustaining combustion process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional combustion-based fire tube heat exchangers are used, then structural simplicity is maintained, but heat transfer efficiency is reduced and heat exchanger size increases

Engineering Contradiction:
Improveheat transfer efficiencyVSAvoidheat exchanger size
Core Design Contradiction:
ProductivityVSVolume of stationary object

Solution Approach 1:

The patent implements periodic combustion pulses within the heat exchanger chambers, creating oscillating flow patterns that enhance heat transfer coefficients. The periodic ignition and extinction of combustion cycles generate dynamic thermal fields that improve heat transfer efficiency by preventing boundary layer stagnation and promoting continuous fluid mixing, thereby achieving higher productivity without proportionally increasing size.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The pulsating combustion process generates acoustic vibrations and pressure oscillations that propagate through the heat exchanger medium. These mechanical vibrations enhance heat transfer by creating turbulent mixing effects and preventing thermal boundary layer formation, allowing for more compact heat exchanger design while maintaining high heat transfer efficiency.

Inventive Principle:
Principle #18Mechanical vibration

2Productivity

If pulse combustion is used to enhance heat transfer, then heat transfer efficiency improves, but thermal stress and structural integrity challenges increase

Engineering Contradiction:
Improveheat transfer efficiencyVSAvoidstructural integrity
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The heat exchanger is divided into multiple independent chambers or tubes that can withstand pressure pulses individually. This segmentation allows the structure to manage thermal stress more effectively, as each segment experiences and dissipates pressure waves separately, preventing cumulative stress buildup that would compromise overall structural integrity while maintaining high heat transfer efficiency through pulsed operation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent carefully controls combustion parameters including pulse frequency, duration, and intensity to optimize heat transfer while staying within structural safety limits. By adjusting these parameters, the system achieves maximum heat transfer efficiency without generating excessive thermal stress that would endanger structural integrity, effectively balancing productivity gains with mechanical safety.

Inventive Principle:
Principle #35Parameter changes

3Use of energy by moving object

If elevated temperature operation is used to improve combustion efficiency, then combustion efficiency increases, but thermal stress and equipment lifespan challenges worsen

Engineering Contradiction:
Improvecombustion efficiencyVSAvoidequipment lifespan
Core Design Contradiction:
Use of energy by moving objectVSDuration of action of stationary object

Solution Approach 1:

The periodic combustion pulses allow the system to achieve high combustion efficiency during active burning phases while providing cooling intervals during extinction phases. This cyclic operation prevents continuous thermal exposure that would accelerate material degradation, thereby extending equipment lifespan while maintaining high energy utilization efficiency during the combustion periods.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent employs thermal barriers, refractory linings, or cooling media as intermediaries between the high-temperature combustion zone and the structural components. These intermediaries protect the equipment structure from direct exposure to extreme temperatures, reducing thermal stress and extending equipment lifespan while allowing the combustion process to operate at high temperatures for maximum efficiency.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Ease of repair

If pulse combustion heat exchanger is used, then maintenance frequency is reduced, but initial device complexity increases

Engineering Contradiction:
Improvemaintenance frequencyVSAvoidsystem complexity
Core Design Contradiction:
Ease of repairVSDevice complexity

Solution Approach 1:

The pulse combustion process creates self-cleaning effects through periodic flow reversal and high-velocity gas streams that remove deposits and contaminants from heat transfer surfaces. This self-service mechanism reduces the frequency of manual maintenance and cleaning operations, offsetting the initial increased device complexity with long-term operational simplicity and reduced maintenance requirements.

Inventive Principle:
Principle #25Self-service

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 enhances heat transfer rates, reduces heat exchanger size, minimizes thermal stress, and maintains continuous operation with reduced maintenance, achieving efficient and reliable performance in high-temperature environments.

Implementation Method 1

combustion-induced acoustic pressure waves

Methodology Applied
Scientific EffectAcoustic pressure waves: Sound

Implementation Method 2

pulsating combustion stream

Methodology Applied
Scientific EffectPulsating flow: Vibration

Implementation Method 3

transfer heat effectively through resonance conduits to a heat transfer medium

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 4

pulsating combustion stream that transfers heat

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 5

aerovalve acts as a fluidic diode to self-aspirate oxidant and fuel

Methodology Applied
Scientific EffectFluidic diode effect: Valve

Implementation Method 6

resonance conduits within the combustion section

Methodology Applied
Scientific EffectResonance: Resonance

Data Source

PatentEP3622218B1Pulse combustion heat exchanger system
Publication Date: 2020.09.09 THERMOCHEM RECOVERY INTERNATIONAL INC
  • EP3622218B1 patent drawingFigure 1
  • EP3622218B1 patent drawingFigure 2
  • EP3622218B1 patent drawingFigure 3

AI summary

A pulse combustion heat exchanger having a longitudinal axis is configured to accept oxidant and fuel and output a cooled combustion stream. The pulse combustion heat exchanger includes an oxidant inlet section that accepts oxidant, a fuel inlet section that accepts fuel, a mixing section that mixes oxidant with fuel, a combustion section that receives the oxidant and fuel and produces a pulsating combustion stream, and a heat transfer section configured to receive the pulsating combustion stream, the heat transfer section includes one or more resonance conduits. Coolant is employed at a plurality of longitudinally spaced-apart transition sections to remove heat.