Cooling system

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Solution Overview

Problem

Existing cooling systems for compressors in refrigeration systems face challenges in uniform cooling of power electronics components, leading to overheating or undercooling issues, and are limited by the type of refrigerant used, resulting in increased complexity, size, and cost.

Innovation Solution

A cooling system utilizing a closed loop Carnot refrigeration cycle with a distributor configured to provide uniform heat transfer through a plurality of pipes connected in parallel, allowing refrigerant fluid to flow from a phase transition state, ensuring all power electronics components are cooled uniformly, and incorporating a solenoid valve for temperature regulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a serpentine heat sink is used to cool power electronics components, then cooling is achieved, but uniform cooling is not provided and modules close to the inlet are over-cooled while modules close to the outlet are under-cooled

Engineering Contradiction:
Improvecooling effectivenessVSAvoidtemperature uniformity
Core Design Contradiction:
TemperatureVSManufacturing precision

Solution Approach 1:

The cooling system divides the refrigerant flow into multiple parallel paths through a distributor with multiple outlets, creating several independent cooling channels. This segmentation ensures that refrigerant is distributed evenly across all power electronics modules, preventing the temperature gradients that occur in single serpentine configurations where inlet modules receive cold refrigerant while outlet modules receive warmed refrigerant.

Inventive Principle:
Principle #1Segmentation

2Reliability

If additional cooling components such as pump and heat exchangers are added, then cooling control is improved, but system complexity, size and costs increase

Engineering Contradiction:
Improvecooling controlVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The distributor is integrated directly into the existing refrigeration circuit, merging the cooling distribution function with the refrigerant flow path. This eliminates the need for separate pumps and heat exchangers, as the refrigerant naturally flows through the distributor and cooling channels under system pressure, achieving reliable cooling control without additional complex components.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The system uses the refrigerant's own flow and phase change properties to provide cooling. The distributor leverages the existing refrigerant pressure and flow dynamics to automatically distribute cooling throughout the power electronics modules without requiring external pumps or control mechanisms, making the system self-regulating and simpler.

Inventive Principle:
Principle #25Self-service

3Temperature

If an expansion valve is used at the inlet of the heat sink, then refrigerant expansion is achieved, but the system is limited to certain refrigerant types and the component is sensitive to refrigerant fluid

Engineering Contradiction:
Improverefrigerant expansionVSAvoidrefrigerant compatibility
Core Design Contradiction:
TemperatureVSAdaptability or versatility

Solution Approach 1:

The distributor is designed to work with various refrigerant types by utilizing general fluid dynamics principles rather than being optimized for a specific refrigerant chemistry. The parallel channel design and distribution mechanism are universally applicable across different refrigerants, eliminating the limitation to certain refrigerant types that plagues expansion valve-based systems.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 solution ensures uniform cooling of power electronics components, preventing overheating or undercooling, and allows for flexibility with various refrigerant types, reducing system complexity and cost while maintaining efficient operation.

Implementation Method 1

The evaporator is configured for evaporating the refrigerant fluid. In the evaporator, the refrigerant fluid absorbs heat from a fluid to be cooled

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 2

the refrigerant fluid is in a phase transition state

Methodology Applied
Scientific EffectPhase transition: Phase Change

Implementation Method 3

The condenser is configured for condensing the refrigerant fluid. In the condenser, the refrigerant fluid releases heat to an external fluid

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 4

The compressor is configured for compressing the refrigerant fluid

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 5

The expansion valve is configured for expanding the refrigerant fluid

Methodology Applied
Scientific EffectExpansion: Pressure Drop

Implementation Method 6

The cooling apparatus is configured to provide a heat transfer from the power electronics components of the variable frequency drive to the refrigerant fluid

Methodology Applied
Scientific EffectHeat conduction: Conduction (thermal)

Data Source

PatentEP3598026B1Cooling system
Publication Date: 2021.04.21 DAIKIN APPLIED EURO SPA
  • EP3598026B1 patent drawingFigure 1
  • EP3598026B1 patent drawingFigure 2
  • EP3598026B1 patent drawingFigure 3~3A

AI summary

A cooling system (1) comprises: a refrigeration circuit for circulating a refrigerant fluid, said refrigeration circuit including: a condenser (2); an expansion valve (3); an evaporator (4); a compressor (5); a variable frequency drive (6) for driving the compressor (5); a cooling apparatus (60) for cooling power electronics components of the variable frequency drive (6), said cooling apparatus (60) including an inlet (71), connected to the refrigeration circuit to receive a portion of the refrigerant fluid from the refrigeration circuit, and an outlet (72), connected to the refrigeration circuit, to re-insert said portion of the refrigerant fluid into the refrigeration circuit, an expansion unit (8), at the inlet (71) of the cooling apparatus (60), and a distributor (7). [Figure 1]