Heat Pump Laundry Treatment Fan Control for Compressor Cooling

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Solution Overview

Problem

Heat pump laundry treatment apparatuses face challenges in achieving economic drying performance due to inefficiencies in cooling the compressor and electronic boards, leading to potential overheating and performance losses.

Innovation Solution

A control unit dynamically adjusts the operation of a cooling fan unit and compressor based on electronic board operation parameters, ensuring minimum cooling capacity is maintained regardless of ambient or refrigerant temperatures, and prioritizes cooling to prevent overheating and maintain stable refrigerant temperatures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the cooling fan unit operates continuously at high capacity to cool the compressor, then the compressor temperature is maintained at optimal levels, but energy consumption increases and drying performance deteriorates

Engineering Contradiction:
Improvecompressor temperatureVSAvoidenergy consumption
Core Design Contradiction:
TemperatureVSUse of energy by moving object

Solution Approach 1:

The cooling fan unit operates dynamically with variable speed rather than continuously at fixed high capacity. The control unit adjusts the fan speed based on real-time compressor temperature feedback, enabling the system to maintain optimal compressor temperature while consuming less energy during periods when full cooling capacity is not required.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

A temperature sensor provides continuous feedback on compressor temperature to the control unit, which then adjusts the cooling fan unit operation accordingly. This closed-loop control system ensures the compressor is cooled only when necessary, preventing both overheating and unnecessary energy consumption during normal operation.

Inventive Principle:
Principle #23Feedback

2Reliability

If the cooling fan unit is activated based on ambient temperature sensors, then the compressor is protected from overheating in hot environments, but the electronic board may still overheat due to localized heat accumulation

Engineering Contradiction:
Improvecompressor protectionVSAvoidelectronic board temperature
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The temperature monitoring system is segmented into multiple sensors: one for ambient temperature and another specifically for electronic board temperature. This allows independent monitoring and control of cooling for different components, ensuring the electronic board receives adequate cooling even when ambient temperatures are moderate.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cooling system provides localized cooling attention to the electronic board through dedicated temperature monitoring. The control unit can adjust cooling fan operation specifically in response to electronic board temperature conditions, ensuring adequate cooling in this heat-prone area regardless of overall ambient temperature conditions.

Inventive Principle:
Principle #3Local quality

3Stability of the object's composition

If compressor cooling is prioritized above all other functions, then the compressor maintains stable performance, but the drying process efficiency decreases due to excessive cooling air consumption

Engineering Contradiction:
Improvecompressor performance stabilityVSAvoiddrying process efficiency
Core Design Contradiction:
Stability of the object's compositionVSProductivity

Solution Approach 1:

The cooling fan unit operates periodically rather than continuously, activating only when compressor temperature thresholds are exceeded. This periodic operation maintains compressor performance stability while minimizing interference with the drying process, as the fan runs only during brief cooling cycles rather than continuously consuming cooling air.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system changes operational parameters dynamically by adjusting fan speed and activation timing based on actual compressor temperature conditions. Rather than maintaining constant high-speed cooling that would interfere with drying efficiency, the system adapts cooling intensity to match actual thermal requirements, preserving drying performance while ensuring compressor stability.

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 approach enhances the drying performance by maintaining constant compressor performance, preventing electronic board malfunctions, and ensuring efficient heat management within the apparatus, even during non-standard operation modes.

Implementation Method 1

a cooling fan unit for cooling the compressor

Methodology Applied
Scientific EffectForced Convection: Forced Convection

Implementation Method 2

a heat pump system having a refrigerant loop, in which the refrigerant fluid is circulated through a first heat exchanger and a second heat exchanger

Methodology Applied
Scientific EffectHeat Exchange: Heat Exchanger

Data Source

PatentEP2920355B1Heat pump laundry treatment apparatus and method of operating a heat pump laundry treatment apparatus
Publication Date: 2021.01.27 ELECTROLUX HOME PROD CORP NV
  • EP2920355B1 patent drawingFigure 1
  • EP2920355B1 patent drawingFigure 2~4a
  • EP2920355B1 patent drawingFigure 3

AI summary

The invention relates to a heat pump laundry treatment apparatus, in particular a heat pump laundry dryer or a heat pump washing machine having drying function, and to a method of operating such a heat pump laundry treatment apparatus. The laundry treatment apparatus comprises a control unit (51) controlling the operation of the laundry treatment apparatus, a laundry treatment chamber for treating laundry using process air, a process air circuit for circulating the process air, a heat pump system having a refrigerant loop (6) in which the refrigerant fluid is circulated through a first and a second heat exchanger, a compressor (14) for circulating the refrigerant fluid through the refrigerant loop (6), and a cooling fan unit (53) for cooling the compressor (14). During the operation the conveyance capacity of the cooling fan unit (53) is varied, and a detector unit (60) for detecting an operation parameter indicates a state of an electronic board (52). The method comprises operating the cooling fan unit (53) in dependency of the electronic board operation parameter, and/or controlling the compressor operation output in dependency of the electronic board operation parameter, wherein the compressor (14) is a variable speed compressor.