Condenser Assembly Tube Layout for R1234yf Sub-Cooling Balance

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Solution Overview

Problem

Current condenser assemblies for motor vehicle air conditioning systems using refrigerant R1234yf exhibit reduced performance and cooling capacity compared to R134a, with existing designs not fully optimizing the sub-cooling section for enhanced efficiency.

Innovation Solution

The design of the condenser assembly includes a specific percentage of heat exchanger tubes and a face area with a defined width-to-height ratio, optimized for three cooling sections in series, which enhances cooling capacity and efficiency by adjusting the distribution of heat exchanger tubes and flow paths.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the sub-cooling section is increased with three areas connected in series, then the sub-cooling performance is improved, but the condensation area is reduced which increases high pressure in the refrigerant circuit

Engineering Contradiction:
Improvesub-cooling performanceVSAvoidhigh pressure in refrigerant circuit
Core Design Contradiction:
Loss of energyVSStress or pressure

Solution Approach 1:

The patent applies parameter changes by optimizing the percentage of heat exchanger tubes in the first group based on the width-to-height ratio of the condenser face. This mathematical relationship allows tuning the condensation area to match the sub-cooling requirements, balancing the refrigerant circuit pressure while maintaining sub-cooling performance for R1234yf refrigerant.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the percentage of heat exchanger tubes is optimized based on width-to-height ratio, then the cooling capacity is improved, but the device complexity increases

Engineering Contradiction:
Improvecooling capacityVSAvoidheat exchanger tube distribution
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent uses parameter changes by establishing a mathematical relationship between the face width-to-height ratio and the percentage of heat exchanger tubes in the first group. This allows systematic optimization of cooling capacity through a single adjustable parameter (tube percentage) that can be calculated from the geometric dimensions, avoiding complex iterative design processes.

Inventive Principle:
Principle #35Parameter changes

3Loss of energy

If the condensation area is reduced to accommodate larger sub-cooling section, then the sub-cooling capacity is enhanced, but the overall efficiency decreases

Engineering Contradiction:
Improvesub-cooling capacityVSAvoidoverall efficiency
Core Design Contradiction:
Loss of energyVSProductivity

Solution Approach 1:

The patent resolves this contradiction by introducing a mathematical optimization that links the sub-cooling section configuration to the condensation area through the face width-to-height ratio. By calculating the optimal percentage of heat exchanger tubes, the system achieves maximum sub-cooling capacity while maintaining sufficient condensation area to preserve overall system efficiency.

Inventive Principle:
Principle #35Parameter changes

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 results in improved cooling capacity and efficiency, particularly suited for refrigerants like R1234yf, with optimized heat transfer areas and flow directions that enhance the performance of the refrigerant circuit.

Implementation Method 1

heat exchanger tubes in a superheating area for cooling the refrigerant in vapor form, a condensation area for condensing the refrigerant

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 2

a condensation area for condensing the refrigerant

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 3

the refrigerant is cooled in a subcooling area to a temperature that is below the condensation temperature of the refrigerant

Methodology Applied
Scientific EffectSub-cooling: Supercooling

Data Source

PatentEP2972040B1Condenser assembly for refrigerant
Publication Date: 2018.10.31 MAHLE INT GMBH
  • EP2972040B1 patent drawingFigure 1~2
  • EP2972040B1 patent drawingFigure 3
  • EP2972040B1 patent drawingFigure 4

AI summary

The invention relates to a condenser assembly (1), comprising a plurality of heat-exchanger pipes (4), which are arranged equidistant from each other having corrugated fins (5) arranged therebetween and lead into deflection regions at both ends and have a free length (Lh) used for heat exchange and, in connection with the corrugated fins (5), form an end area (S) having a width corresponding to the free length (Lh) of the heat-exchanger pipes (4) and a height (Lv), such that the end area (S) results from the product of width and height, wherein the heat-exchanger pipes (4) are connected in parallel in groups and the individual groups are connected in series, wherein the heat-exchanger pipes (4) of the individual groups are arranged adjacent and each group comprises at least two heat-exchanger pipes (4). The percentage share (P) of the heat-exchanger pipes (4) of the first group results from 26.162 In (S/dm2) - 40.746 ≤ P ≤ 25.49 In (S/dm2) - 27.842 for an end area (S) having a ratio of width to height in the range of 0.5 to 1.0, an end area (S) in the range of 10 to 30 dm2, and a specification of the area of the end area (S) in dm2.