Power Electronics Heat Exchanger on Heating Return for Waste Heat Recovery

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Solution Overview

Problem

Existing heat pump devices with speed-controlled compressors lack efficient heat dissipation for power electronics units, leading to reduced performance and increased condensation during cooling modes.

Innovation Solution

A heat pump device with a power electronics heat exchanger integrated into the heating and/or domestic water system return, utilizing a heat exchanger with inflow and outflow channels and connecting pipes to dissipate waste heat from the power electronics unit, and featuring a design that optimizes heat transfer through a combination of channel geometry and flow distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the power electronics unit is used to control the compressor speed, then the heating capacity can be adjusted to actual needs, but the power electronics unit generates waste heat that reduces system efficiency

Engineering Contradiction:
Improveheating capacity adjustmentVSAvoidwaste heat from power electronics
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The patent converts the waste heat generated by the power electronics unit into a useful resource by integrating a heat exchanger that transfers this heat to the heating water system. The heat exchanger is coupled to the power electronics unit and the heating water system, allowing the waste heat to be utilized for heating purposes, thereby improving overall system efficiency and reducing energy loss.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Ease of operation

If the power electronics unit is integrated into the heat pump system, then compressor control is improved, but the waste heat causes reduced heat sink temperature and increased condensation during cooling modes

Engineering Contradiction:
Improvecompressor controlVSAvoidheat sink temperature
Core Design Contradiction:
Ease of operationVSTemperature

Solution Approach 1:

The patent addresses the temperature issue by capturing the waste heat from the power electronics unit through a heat exchanger and redirecting it to the heating water system. This prevents the waste heat from lowering the heat sink temperature and causing condensation during cooling modes, while still maintaining effective compressor control.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Loss of energy

If a separate cooling system is added for the power electronics unit, then heat dissipation is improved, but device complexity increases

Engineering Contradiction:
Improveheat dissipation efficiencyVSAvoidsystem structure
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent merges the cooling function for the power electronics unit with the existing heating water system by integrating a heat exchanger that serves dual purposes: cooling the power electronics unit and providing heated water for the heating system. This eliminates the need for a separate cooling system, reducing device complexity while maintaining effective heat dissipation.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The heat exchanger is designed to perform multiple functions: it cools the power electronics unit by transferring waste heat, and simultaneously provides thermal energy to the heating water system. This multi-functionality reduces the overall system complexity by consolidating cooling and heating functions into a single integrated component.

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

This configuration enhances heat dissipation efficiency, reduces heat sink temperatures, and minimizes condensation on electronics during cooling modes, improving overall system performance and energy dissipation capabilities.

Implementation Method 1

a heat exchanger is provided on the heating return, which transfers the heat loss from the power electronics unit to the heat transfer medium (heating water) flowing through the heat exchanger

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 2

the heat transfer medium (heating water) flowing through the heat exchanger

Methodology Applied
Scientific EffectHeat absorption: Heat Exchanger

Data Source

PatentEP2808624B1Heat pump device
Publication Date: 2021.05.19 STIEBEL ELTRON GMBH & CO KG
  • EP2808624B1 patent drawingFigure 1~2A
  • EP2808624B1 patent drawingFigure 2B
  • EP2808624B1 patent drawingFigure 2C~3

AI summary

A heat pump device is provided with a cooling circuit comprising an evaporator, a speed-controlled compressor, a condenser coupled to a heating and/or domestic hot water system, an expansion valve, and a power electronics unit (PE) for controlling the compressor speed. The heat pump device also includes a power electronics heat exchanger (PE) for cooling the power electronics unit (PE). The power electronics heat exchanger (PE) has an inlet channel (PE10) and an outlet channel (PE20), as well as multiple connecting channels (PE30) between the inlet channel (PE10) and the outlet channel (PE20). The power electronics unit (PE) is connected to the connecting channels (PE30) for cooling. A heat transfer medium flowing through the heating water and/or domestic hot water system passes through the power electronics heat exchanger (PE) to cool the power electronics unit (PE).