Heat Pump Dryer Compressor Fan Control for Adaptive Cooling

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Solution Overview

Problem

Heat pump laundry dryers and washing machines face challenges in achieving optimal drying performance and energy efficiency due to the limitations in controlling the cooling fan unit's operation based on various input variables, leading to suboptimal operating conditions.

Innovation Solution

A method is introduced to dynamically modify the operation parameters of the cooling fan unit in response to multiple input variables, such as laundry type, drying program, residual humidity, and ambient conditions, allowing for adjustable cooling power and optimized operation of the heat pump system during each drying cycle.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by stationary object

If the cooling fan unit operates at fixed speed, then the structure is simple, but the energy efficiency is suboptimal under varying operating conditions

Engineering Contradiction:
Improveenergy efficiencyVSAvoidcontrol system complexity
Core Design Contradiction:
Use of energy by stationary objectVSDevice complexity

Solution Approach 1:

The cooling fan unit's operating parameters are dynamically adjusted based on real-time monitoring of compressor temperature and heat pump system operating conditions. The control unit modifies fan speed and cooling intensity adaptively, transitioning from fixed-speed operation to variable-speed control that responds to actual thermal conditions, thereby optimizing energy efficiency without excessive complexity

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the operating parameters of the cooling fan unit (speed, cooling power) in response to varying input variables such as compressor temperature, laundry type, and drying program requirements. This parameter adaptation allows the system to maintain optimal cooling efficiency across different operating scenarios while avoiding the need for overly complex control mechanisms

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the cooling fan unit is operated continuously at high power, then the compressor cooling is sufficient, but the energy consumption increases

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

Solution Approach 1:

The cooling fan unit operates in periodic cycles rather than continuously, with the control unit activating and deactivating the fan based on compressor temperature thresholds and system operating conditions. This periodic operation ensures adequate compressor cooling while significantly reducing overall energy consumption compared to continuous high-power operation

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system applies partial cooling action by adjusting the fan unit's cooling power to match actual compressor heat generation. Instead of applying full cooling capacity continuously, the system provides just sufficient cooling during periods when it is needed, reducing energy waste while maintaining compressor reliability

Inventive Principle:
Principle #16Partial or excessive action

3Productivity

If the cooling fan unit operates without adaptive control, then the system is simple to operate, but the drying performance is suboptimal

Engineering Contradiction:
Improvedrying performanceVSAvoidoperation simplicity
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The cooling fan unit operates autonomously with the control unit automatically adjusting fan parameters based on sensor inputs from the heat pump system. The system self-regulates cooling requirements without user intervention, improving drying performance through adaptive control while maintaining ease of operation as the process occurs automatically based on real-time system conditions

Inventive Principle:
Principle #25Self-service

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 drying performance and energy efficiency by maintaining ideal operating conditions, ensuring the heat pump system operates at maximum efficiency and improves energy savings by adapting cooling requirements in real-time.

Implementation Method 1

a cooling fan unit for cooling the compressor

Methodology Applied
Scientific EffectHeat transfer: Convection

Implementation Method 2

Heat exchangers located along the air-circulating pipe are arranged for an exchange of heat energy between a refrigerant and the air flow within the pipe

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 3

Heat exchangers located along the air-circulating pipe are arranged for an exchange of heat energy between a refrigerant and the air flow within the pipe

Methodology Applied
Scientific EffectPhase change: Phase Change

Data Source

PatentEP2920356B1Method of operating a heat pump laundry dryer and heat pump laundry dryer or heat pump washing machine having drying function
Publication Date: 2021.07.28 ELECTROLUX HOME PROD CORP NV
  • EP2920356B1 patent drawingFigure 1~2
  • EP2920356B1 patent drawingFigure 3a~3c
  • EP2920356B1 patent drawingFigure 4~6

AI summary

The invention relates to a method of operating a heat pump laundry dryer or a heat pump washing machine having drying function and to such a laundry dryer or washing machine, wherein the laundry dryer or washing machine comprises: a control unit (30) controlling the operation of the laundry dryer or washing machine, a laundry treatment chamber (18) for treating laundry using process air, a process air circuit for circulating the process air, a heat pump system (4) having a refrigerant loop, in which the refrigerant fluid is circulated through a first and a second heat exchanger (10, 12), a compressor (14) for circulating the refrigerant fluid through the refrigerant loop, and a cooling fan unit (24) for cooling the compressor (14), and wherein the method comprises: modifying or changing an operation parameter set of the cooling fan unit (24) in dependency of at least one of the following input variables: a user selectable input variable, a working parameter of the laundry drum, a working parameter of a process air fan, a working parameter of an electric driving motor, a working parameter of the compressor, a drying progress status parameter or a status parameter of the laundry to be dried, and an environment parameter of the treatment apparatus environment.