Absorption Plate Layout for Mixed-Flow Refrigerant Absorption

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing absorption air conditioning systems for vehicles face efficiency limitations due to saturation of the absorbent fluid and complex, costly manufacturing processes, particularly in the automotive field where compactness and flexibility are crucial.

Innovation Solution

An absorption plate design featuring two exchange surfaces arranged to force the absorbent fluid to mix, enhancing refrigerant absorption efficiency without additional components, allowing for compact and cost-effective implementation by ensuring homogeneous temperature and concentration across the exchange surfaces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of stationary object

If the absorbent fluid flows through a conventional absorption plate, then the system size is reduced, but the absorption efficiency is limited due to heat transfer rate constraints

Engineering Contradiction:
Improvesystem sizeVSAvoidabsorption efficiency
Core Design Contradiction:
Volume of stationary objectVSProductivity

Solution Approach 1:

The exchange surfaces are designed as porous grids that allow the absorbent fluid to pass through while providing extensive surface area for refrigerant absorption. The porous structure enables the fluid to be distributed throughout the grid thickness, creating multiple absorption zones and enhancing heat transfer efficiency without increasing overall system volume.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The invention transitions from a conventional single-sided absorption approach to a through-flow configuration where the absorbent fluid passes through the exchange surface from one side to the other. This dimensional change allows absorption to occur across the entire thickness of the plate, effectively utilizing the third dimension to increase absorption capacity within the same footprint.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Productivity

If protrusions are added to tube surfaces to create turbulence, then absorption efficiency improves, but manufacturing complexity and cost increase significantly

Engineering Contradiction:
Improveabsorption efficiencyVSAvoidmanufacturing complexity
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The relative arrangement of the two exchange surfaces themselves creates the turbulence and mixing effects needed to enhance absorption. The surfaces force the absorbent fluid to cross through them and mix, generating the desired flow patterns without requiring additional protrusions or complex surface modifications. The system uses its own structural configuration to achieve the mixing function.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention combines the exchange surface structure with the mixing function into a single integrated component. Rather than adding separate protrusions or turbulence-generating elements to the tubes, the exchange surfaces are designed to perform both heat transfer and fluid mixing functions simultaneously, simplifying manufacturing and reducing component count.

Inventive Principle:
Principle #5Merging (Combining)

3Productivity

If the passage section between exchange surfaces is reduced to force fluid crossing, then mixing efficiency improves, but pressure drop increases

Engineering Contradiction:
Improvemixing efficiencyVSAvoidpressure drop
Core Design Contradiction:
ProductivityVSStress or pressure

Solution Approach 1:

The exchange surfaces are designed with locally varied properties, including regions of different porosity and thickness. This allows the passage section to be reduced in specific areas where mixing is most needed, while maintaining larger passage sections in other areas to minimize overall pressure drop. The local quality variation enables optimized mixing efficiency without excessive pressure penalties.

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 design significantly improves absorption efficiency by ensuring uniform mixing of the absorbent fluid, achieving high yields in a compact form suitable for automotive integration while maintaining economic feasibility.

Implementation Method 1

the exothermic absorption of a so-called refrigerant fluid in the vapor phase taking place through the said two exchange surfaces by increasing a concentration of the refrigerant fluid in the absorbing fluid

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Implementation Method 2

the relative arrangement of the two exchange surfaces forces at least a part of the flow of absorbent fluid to cross at least once one of the exchange surfaces and causes mixing of the flow of absorbent fluid

Methodology Applied
Scientific EffectMixing:

Implementation Method 3

the relative arrangement of the two exchange surfaces causing mixing of the flow of absorbent fluid is a decrease in the passage section between the exchange surfaces for the flow of absorbent fluid

Methodology Applied
Scientific EffectFluid flow:

Data Source

PatentEP2736742B1Absorption plate for an air conditioner
Publication Date: 2015.09.09 PEUGEOT CITROEN AUTOMOBILES SA
  • EP2736742B1 patent drawingFigure 1~2

AI summary

The invention relates to an absorption plate, in particular of an absorption air conditioner for a vehicle, crossed by a stream of liquid absorbent fluid (10) flowing between two exchange surfaces (35) arranged relatively opposite one another, the exothermal absorption of a so-called coolant fluid in vapour phase taking place through said exchange surfaces (35) by increasing a concentration of the coolant fluid in the absorbent fluid (10), characterised in that the relative arrangement of the two exchange surfaces (35) forces at least one portion of the stream of absorbent fluid (10) to pass at least once through one of the exchange surfaces (35) and causes mixing of the stream of absorbent fluid (10).