Heat Pipe Compressor Cooling for Heat Pump Waste Heat Recovery

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Solution Overview

Problem

Existing heat pumps face issues with compressor overheating, leading to reduced efficiency and reliability due to inadequate cooling mechanisms, which also affect the refrigerant compression process.

Innovation Solution

A heat pump system incorporating a heat pipe with a cylindrical enclosure around the electric motor and a ring-shaped tube surrounding it, connected to a third part with a heat dispersing surface, along with a control unit to analyze and modify refrigerant input parameters, enhancing compressor performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a fan is installed to enhance heat exchange efficiency by supplying a large air volume, then heat exchange efficiency is improved, but the compressor may be overheated and reliability is degraded

Engineering Contradiction:
Improveheat exchange efficiencyVSAvoidcompressor reliability
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

A heat pipe is introduced as an intermediary heat exchange component between the compressor and the surrounding air. The heat pipe absorbs waste heat from the compressor through thermal conduction and dissipates it to the air through convection and radiation, serving as a mediator that protects the compressor from overheating while maintaining efficient heat recovery

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical fan-based forced convection system with a passive heat pipe system that utilizes phase change and thermal conduction. This substitution eliminates the need for additional mechanical cooling components while effectively managing compressor temperature and recovering waste heat

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Use of energy by moving object

If heat exchange means are used to recover waste energy, then energy efficiency is improved, but the heat exchange means may be overheated due to capacity limitations

Engineering Contradiction:
Improveenergy efficiencyVSAvoidheat exchange means temperature
Core Design Contradiction:
Use of energy by moving objectVSTemperature

Solution Approach 1:

The heat pipe utilizes phase transitions of the working fluid inside it - the fluid evaporates at the heating end (absorbing heat from the compressor) and condenses at the cooling end (releasing heat to the air). This phase change mechanism enables high-capacity heat transfer that can handle the thermal load without overheating, significantly improving energy recovery efficiency

Inventive Principle:
Principle #36Phase transitions

3Reliability

If the compressor is overheated, then reliability is degraded, but compression efficiency is also degraded leading to increased energy consumption

Engineering Contradiction:
Improvecompressor reliabilityVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent converts the harmful waste heat generated by the compressor into a beneficial resource by using the heat pipe to transfer this heat to the air circulation system. This not only prevents compressor overheating and maintains reliability but also improves overall system efficiency by utilizing what would otherwise be wasted energy, reducing total energy consumption

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

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 system effectively recovers waste heat from the compressor and electric motor, improving refrigerant input parameters, reducing power consumption, and enhancing compressor reliability and efficiency without additional cooling components.

Implementation Method 1

a heat pipe with a closed inner space containing a heat transfer medium, wherein the heat pipe has a first part that is in heat accepting contact with the compressor, a second part for heat transfer, and a third part containing a heat dispersing surface

Methodology Applied
Scientific EffectHeat pipe: Heat Pipe

Implementation Method 2

a heat pipe with a closed inner space containing a heat transfer medium

Methodology Applied
Scientific EffectPhase change: Phase Change

Data Source

PatentEP4145062B1Heat pump system with improved compressor cooling and process for operating the heat pump system
Publication Date: 2026.04.22 BSH HAUSGERATE GMBH
  • EP4145062B1 patent drawingFigure 1~2
  • EP4145062B1 patent drawingFigure 3~5
  • EP4145062B1 patent drawingFigure 6~8

AI summary

The invention relates to a heat pump system, including a heat pump containing an evaporator as a heat source, a condenser as a heatsink, a compressor 2 for driving and compressing a flow of a refrigerant, a throttle for expanding the refrigerant flow, and a refrigerant channel for circulating the refrigerant flow sequentially through the evaporator, the condenser, the throttle, and the compressor 2; an electrical motor 4,5,6 for driving the compressor 3; a heat pipe 7 with a closed inner space 12 containing a heat transfer medium, wherein the heat pipe 7 has a first part 8 that is in heat accepting contact with the compressor 3 and a second part 10,14 for heat transfer, and a third part 16 containing a heat dispersing surface; wherein the first part 8 of the heat pipe 7 is provided as an essentially cylindrical enclosure 11 around the electrical motor 4,5,6. The invention also relates to a process for operating the heat pump system.