Sulfonated Block Copolymer Membrane for ERV Heat Recovery

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Solution Overview

Problem

Energy recovery ventilation (ERV) systems face challenges in efficiently exchanging both sensible and latent heat between air streams due to limitations in membrane technology, particularly in facilitating effective water vapor transport for latent heat transfer.

Innovation Solution

A membrane comprising a microporous substrate laminated with a sulfonated block copolymer, which enhances water vapor transport rates, is used in an ERV core unit, allowing for improved sensible and latent heat exchange between intake and exhaust air streams.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a thin layer barrier is used for heat exchange, then sensible heat transfer is improved, but latent heat transfer is insufficient

Engineering Contradiction:
Improvesensible heat transferVSAvoidwater vapor transport
Core Design Contradiction:
TemperatureVSQuantity of substance

Solution Approach 1:

The patent uses a composite membrane structure combining a microporous substrate (providing mechanical strength and vapor transport pathways) with a sulfonated block copolymer coating (providing selective vapor permeability and latent heat transfer capability). This composite approach allows simultaneous achievement of sensible heat transfer through the thin structure and latent heat transfer through the sulfonated polymer's water vapor transport properties.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The microporous substrate provides a three-dimensional network of pores that facilitate water vapor transport while maintaining mechanical integrity. The porous structure allows vapor molecules to diffuse through the membrane, enabling latent heat transfer without requiring a thick barrier that would impede sensible heat transfer.

Inventive Principle:
Principle #31Porous materials

2Device complexity

If conventional membranes are used, then structural simplicity is maintained, but energy recovery efficiency is insufficient

Engineering Contradiction:
Improvemembrane structureVSAvoidenergy recovery efficiency
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The patent modifies the chemical and physical parameters of the membrane by using sulfonated block copolymers with specific ion exchange capacities (0.5-2.0 meq/g) and controlled molecular weights. These parameter changes enhance the membrane's water vapor transport rate and selective permeability, thereby improving energy recovery efficiency while maintaining a relatively simple laminate structure.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The sulfonated block copolymer coating provides localized functional properties at the membrane surface and within the pore structure, creating regions with enhanced vapor transport capability. The block copolymer's micellar structure creates hydrophilic channels within the hydrophobic matrix, providing localized pathways for water vapor transport that improve overall energy recovery efficiency.

Inventive Principle:
Principle #3Local quality

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 use of this membrane significantly improves latent heat exchange by facilitating efficient water vapor transport, leading to enhanced energy recovery and efficiency in ERV systems.

Implementation Method 1

a sulfonated block copolymer having at least two polymer end blocks that contain little or no sulfonic acid or sulfonate functionality and at least one polymer interior block which contains an effective amount of sulfonic acid or sulfonate functionality... significantly improves latent heat exchange by facilitating efficient water vapor transport

Methodology Applied
Scientific EffectVapor transport: Permeation

Implementation Method 2

Sensible heat exchange is generally simpler to accomplish since a thin layer barrier may transfer heat rather easily

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentEP2622016B1Energy recovery ventilation sulfonated block copolymer laminate membrane
Publication Date: 2023.06.07 KRATON POLYMERS US LLC
  • EP2622016B1 patent drawingFigure 1~2
  • EP2622016B1 patent drawingFigure 3~4
  • EP2622016B1 patent drawingFigure 5~6

AI summary

A core unit for an energy recovery system for exchanging heat and vapor between two independent intake and exhaust airstreams without intermixing thereof, the core unit having a fibrous microporous support substrate and a sulfonated block copolymer having at least one end block A and at least one interior block B wherein each A block contains essentially no sulfonic acid or sulfonate ester functional groups and each B block is a polymer block containing from about 10 to about 100 mol percent sulfonic acid or sulfonate ester functional groups based on the number of monomer units, and wherein the sulfonated block copolymer is laminated on the microporous support substrate.