Adsorption Cell Geometry for Thermal Wave Compressor Compactness

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing adsorption heat pump systems are bulky due to low pressures used for water vapor condensation and evaporation, limiting specific cooling power (SCP) and coefficient of performance (COP), and there is a need for more efficient and compact designs.

Innovation Solution

The system employs a thermal wave operation with adsorption cells having a high contact area between the heat transfer fluid channel and solid adsorption material, with a characteristic dimension of less than 1 cm, and a method involving four phases of operation to enhance SCP while maintaining high COP, using a cluster of adsorption cells with optimized manifold arrangements and heat transfer fluid management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If water is used as refrigerant with reduced pressures for condensation and evaporation, then the system can operate with non-freon gases harmless to the ozone layer, but the specific cooling power (SCP) is lowered and the system becomes bulky in size

Engineering Contradiction:
Improveozone layer harmVSAvoidsystem size
Core Design Contradiction:
Object-affected harmful factorsVSVolume of moving object

Solution Approach 1:

The patent changes the operating pressure parameters of the adsorption compressor to enable operation at higher pressures, which increases the density of the refrigerant vapor and thereby increases the specific cooling power (SCP) while reducing the required system volume. This parameter change allows the system to maintain environmental compatibility while improving compactness.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If thermal wave operation is applied to increase efficiency, then the heat pump performance is substantially increased, but the system complexity increases due to the need for precise temperature profile control

Engineering Contradiction:
Improveheat pump performanceVSAvoidtemperature profile control
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent implements periodic action by alternately heating and cooling the two adsorption beds in a cyclic manner. This periodic operation creates the thermal wave effect where one bed is in desorption mode while the other is in adsorption mode, thereby maintaining continuous refrigerant circulation and improving heat pump performance without requiring complex continuous control systems.

Inventive Principle:
Principle #19Periodic action

3Ease of operation

If batch cooling and batch heating of adsorbing material is used, then the system operation is simple, but the cooling power is not substantially constant and efficiency is reduced

Engineering Contradiction:
Improveoperation simplicityVSAvoidcooling power constancy
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The patent achieves continuity of useful action by operating two adsorption beds in parallel with opposite phases. While one bed undergoes desorption (producing refrigerant vapor), the other undergoes adsorption (consuming refrigerant vapor). This continuous alternating operation ensures that refrigerant is continuously circulated through the system, maintaining constant cooling power output.

Inventive Principle:
Principle #20Continuity of useful action

4Productivity

If the characteristic dimension of adsorption material is reduced to enhance thermal wave propagation, then the SCP is improved, but the heat transfer surface area is reduced

Engineering Contradiction:
Improvespecific cooling powerVSAvoidheat transfer surface area
Core Design Contradiction:
ProductivityVSArea of stationary object

Solution Approach 1:

The patent compensates for the reduced heat transfer surface area by optimizing the geometric configuration and arrangement of the adsorption material particles. By controlling particle size distribution, porosity, and spatial arrangement, the system enhances thermal wave propagation through the adsorption bed while maintaining effective heat transfer surface area through three-dimensional optimization of the particle structure.

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

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 results in improved SCP and COP, achieving a more compact and efficient adsorption compressor system with enhanced thermal wave propagation and refrigerant adsorption/desorption efficiency.

Implementation Method 1

The adsorbing vapor is forced out of the solid adsorption material by heating the material with a heat transfer fluid

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 2

the water vapor is condensed in a high pressure condenser

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 3

the condensed water is guided through a pressure release valve, where due to the Joules Thomson effect, the temperature decreases substantially adiabatically

Methodology Applied
Scientific EffectJoules Thomson effect: Joule-Thomson Effect

Implementation Method 4

In a low pressure evaporator, the water is re-evaporated and can be returned through a set of check valves to that adsorption bed that is cold and accepting the vapor to adsorb. The evaporator provides the actual thermal cooling power of the heat pump.

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 5

the water vapor originating from the adsorption beds is guided through a set of check valves to a condenser of a heat pump

Methodology Applied
Scientific EffectAdsorption: Adsorption

Data Source

PatentEP2678620B1Adsorption cell for an adsorption compressor and method of operation thereof
Publication Date: 2018.09.12 COOLL SUSTAINABLE ENERGY SOLUTIONS
  • EP2678620B1 patent drawingFigure 1
  • EP2678620B1 patent drawingFigure 2
  • EP2678620B1 patent drawingFigure 3~5

AI summary

The invention is directed to an adsorption cell suitable for a thermal wave operated adsorption compressor comprising: - an elongated solid adsorption material; - an elongated heat transfer fluid (HTF) channel in direct heat transferring contact with the outside surface of the solid adsorption material, wherein the characteristic dimension r (e.g. the radius) and the length L of said adsorption material are chosen such that L/r > 10, more preferably larger than 15, most preferably larger than 20.