Method for applying an absorbent or refrigerant

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Solution Overview

Problem

Thermally driven absorption refrigeration systems face limitations, particularly with pure water as a refrigerant at ambient temperatures below 0°C, due to high heating requirements and inefficiencies with ionic liquids, which result in poorer heat and mass transfer densities compared to aqueous lithium bromide solutions.

Innovation Solution

A distribution device with a jet device is used to radiate the sorbent or refrigerant as jets onto the heat exchange surface, creating turbulent flows that enhance the absorption and desorption processes, improving heat and mass transfer densities by overcoming the limitations of ionic liquids and allowing efficient operation at temperatures below 0°C.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If ionic liquids are used as absorbent, then the system can operate at temperatures below 0°C, but the heat and mass transfer densities are poorer

Engineering Contradiction:
Improveoperating temperatureVSAvoidheat and mass transfer densities
Core Design Contradiction:
TemperatureVSProductivity

Solution Approach 1:

The patent applies dynamic jet injection to introduce the absorbent into the absorber, creating turbulent flow patterns that enhance heat and mass transfer. The jet device generates controlled chaos and mixing in the absorbent flow, transforming the static or laminar flow of ionic liquids into dynamic turbulent flow, thereby overcoming the poor transfer densities while maintaining sub-zero operating temperatures

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the flow regime parameter from laminar to turbulent by using jet injection. This parameter change fundamentally alters the heat and mass transfer characteristics of the ionic liquid absorbent, increasing the transfer densities by an order of magnitude while preserving the ability to operate at temperatures below 0°C

Inventive Principle:
Principle #35Parameter changes

2Productivity

If aqueous lithium bromide solution is used, then high heat and mass transfer densities are achieved, but the system cannot operate efficiently at temperatures below 0°C

Engineering Contradiction:
Improveheat and mass transfer densitiesVSAvoidoperating temperature
Core Design Contradiction:
ProductivityVSTemperature

Solution Approach 1:

The patent changes the absorbent type parameter from aqueous lithium bromide solution to ionic liquids, which have different thermodynamic properties that enable sub-zero operation. Combined with the jet injection method, this parameter change allows the system to achieve both high transfer densities and low operating temperatures

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If absorbent is applied by sprinkling, then the application is simple, but the heat and mass transfer efficiency is limited

Engineering Contradiction:
Improveapplication simplicityVSAvoidheat and mass transfer efficiency
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The patent uses hydraulic jet injection to deliver the absorbent into the absorber. The jet device utilizes fluid dynamics and pressure-driven flow to inject the absorbent directly onto the heat exchange surface, creating turbulent flow patterns that dramatically enhance heat and mass transfer efficiency compared to simple sprinkling methods

Inventive Principle:
Principle #29Pneumatics and hydraulics

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 approach enables the use of ethanol with ionic liquids to achieve similar heat and mass transfer densities as aqueous lithium bromide solutions, facilitating efficient operation at low temperatures and improving system performance with increased heat transfer and reduced viscosity-related issues.

Implementation Method 1

forming turbulent flows of the sorbent on the heat exchange surface

Methodology Applied
Scientific EffectTurbulence: Turbulence

Implementation Method 2

the sorbent... at least partially absorbs the refrigerant from the refrigerant environment

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Implementation Method 3

at least partially desorbs the refrigerant from the sorbent into an environment of the sorbent

Methodology Applied
Scientific EffectDesorption: Desorption

Implementation Method 4

transfers the released heat (via the heat exchange surface) to the heat exchanger

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentEP3676545B1Method for applying an absorbent or refrigerant
Publication Date: 2023.12.13 TECH UNIV BERLIN
  • EP3676545B1 patent drawingFigure 1
  • EP3676545B1 patent drawingFigure 2~3

AI summary

The invention relates to a device for an absorption refrigerator or an absorption heat pump having a heat exchanger through which a working medium flows, said device having a distribution apparatus for a sorbent which is designed to apply the sorbent to a heat exchange surface of the heat exchanger (1) in a refrigerant environment such that the sorbent, which forms a working pair with the refrigerant, at least partially absorbs the refrigerant from the refrigerant environment and emits heat released in the process to the heat exchanger, or at least partially desorbs the refrigerant from the sorbent into the environment of the sorbent and in the process receives heat from the heat exchanger. The distribution apparatus has a jet apparatus (2) which is designed to spray the sorbent in the form of one or more jets (5) onto the heat exchange surface, forming turbulent flows of the sorbent on the heat exchange surface. The invention also relates to an absorber, a desorber, an absorption refrigerator, an absorption heat pump, a method for applying an absorbent, a device for a refrigerator or a heat pump, and a method for applying a refrigerant.