Reactor Cooling Structure Using Enclosed Refrigerant Flow Passages

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Solution Overview

Problem

Existing reactor designs for power conversion devices face challenges in efficiently cooling the reactor components, leading to heat transfer issues that can damage adjacent components, and restrictions on size reduction due to cooling pipe placement and heat recovery limitations.

Innovation Solution

A reactor design featuring a box-shaped inner case with refrigerant flow passages between the inner and outer cases, where the coil and core are enclosed by refrigerant, with terminals exposed on one side, and optionally filled with thermal conductive potting material or insulating oil, ensuring effective heat transfer and thermal insulation of outer surfaces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If cooling pipes are provided passing through the core to cool the reactor, then heat recovery is improved, but the position of cooling pipes is restricted and size reduction becomes difficult

Engineering Contradiction:
Improveheat recoveryVSAvoidcase size
Core Design Contradiction:
Loss of energyVSVolume of moving object

Solution Approach 1:

The patent introduces a cooling plate as an intermediary component between the coil and the case. The cooling plate has a cooling fin that contacts the coil for heat absorption, and a heat transfer portion that transfers heat to the cooling pipe. This intermediary structure allows flexible positioning of the cooling pipe without restricting its placement through the core, enabling both effective heat recovery and case size reduction.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If the coil and core are exposed except for contacting surfaces with cooler, then structure simplicity is maintained, but heat transfer to other components occurs through air and radiation

Engineering Contradiction:
Improvestructure simplicityVSAvoidheat transfer to other components
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The patent uses a cooling plate as a thin film structure that covers the coil and core. The cooling plate has high thermal conductivity and acts as a thermal shield, preventing heat transfer from the coil and core to surrounding components through air conduction and radiation. This maintains structural simplicity while effectively blocking harmful heat transfer paths.

Inventive Principle:
Principle #30Flexible shells and thin films

3Temperature

If potting material is used to fill gaps between cooler and coil, then terminal cooling is improved, but heat transfer to non-terminal components is not prevented

Engineering Contradiction:
Improveterminal temperatureVSAvoidheat transfer to non-terminal components
Core Design Contradiction:
TemperatureVSObject-generated harmful factors

Solution Approach 1:

The patent extracts the cooling function from the potting material and concentrates it in the cooling plate structure. The cooling plate is specifically designed with a cooling fin that contacts the coil and a heat transfer portion for the cooling pipe, creating a dedicated heat dissipation path. This separates the cooling function from the structural potting material, allowing effective cooling of both terminals and non-terminal components through the specialized cooling plate design.

Inventive Principle:
Principle #2Taking out (Extraction)

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 design effectively cools the reactor components by enclosing them in refrigerant flow passages, reducing thermal influence on adjacent components and allowing for size reduction while maintaining efficient heat recovery and thermal insulation.

Implementation Method 1

heat is surely transferred to the refrigerant through the inner case

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 2

A refrigerant flowing into the outer case from the refrigerant inlet flows in the reactor through the refrigerant flow passages

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 3

a core made of magnetic powder mixture resin that fills the inner case which embed the coil

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3836174B1reactor
Publication Date: 2023.09.13 MEIDENSHA CORP
  • EP3836174B1 patent drawingFigure 1
  • EP3836174B1 patent drawingFigure 2
  • EP3836174B1 patent drawingFigure 3

AI summary

A box-shaped inner case (3) is accommodated in a box-shaped outer case (2), and refrigerant flow passages (27) are formed at five surfaces except an opening surface (24) by gaps between the inner and outer cases. A Gap of an opening edge of the outer case (2) and an opening edge of the inner case (3) is covered with a frame-shaped cover (6). A coil (4) is placed in the inner case (3), and the inner case (3) is filled with magnetic powder mixture resin so that the coil (4) except the terminals (4a, 4b) is embedded. A core (5) is made of the magnetic powder mixture resin. Cooling water flows along a longitudinal direction of the outer case (2) with one of refrigerant pipe connecters (15) being a refrigerant inlet and the other of the refrigerant pipe connecters (15) being a refrigerant outlet.