A method for controlling a laundry drying machine of the type comprising a heat pump system and a corresponding laundry drying machine
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Solution Overview
Problem
Conventional laundry dryers with heat pump systems are inefficient in terms of energy consumption and drying time, leading to high costs for users, as they often rely on fixed or user-selectable compressor speeds that do not adapt to the changing moisture levels during the drying cycle.
Innovation Solution
A method for controlling the heat pump system in laundry dryers with a compressor of variable rotation speed, adjusting power based on the amount of water removed during different time intervals to optimize energy usage and reduce drying time, by comparing efficiency parameters and adjusting compressor speed accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If fixed speed compressor is used in heat pump system, then device complexity is reduced, but energy efficiency and drying performance deteriorate due to inability to adapt to changing moisture levels
Solution Approach 1:
The patent applies dynamics by transitioning from a fixed-speed compressor to a variable-speed compressor that dynamically adjusts its rotation speed based on real-time detection of moisture levels in the laundry. The control unit modifies compressor speed according to the amount of water removed during different time intervals, enabling the system to adapt to changing drying conditions and optimize energy consumption throughout the drying cycle.
Solution Approach 2:
The patent implements feedback control by continuously detecting the amount of water removed from laundry during successive time intervals and using this information to adjust compressor speed. The control unit compares efficiency parameters between time intervals and provides feedback signals to modify compressor operation, creating a closed-loop control system that optimizes energy efficiency based on actual drying progress.
2Adaptability or versatility
If user-selectable compressor speeds are used, then adaptability to different drying preferences is improved, but energy efficiency deteriorates because speeds are not optimized based on actual moisture levels
Solution Approach 1:
The patent applies self-service by enabling the drying system to automatically optimize its own operation without requiring user intervention. The control unit independently monitors drying progress, detects moisture levels, and adjusts compressor speed to achieve optimal energy efficiency. The system serves itself by making real-time decisions based on actual drying conditions rather than relying on pre-selected user preferences.
Solution Approach 2:
The patent implements feedback control by continuously detecting the amount of water removed from laundry during successive time intervals and using this information to adjust compressor speed. The control unit compares efficiency parameters between time intervals and provides feedback signals to modify compressor operation, creating a closed-loop control system that optimizes energy efficiency based on actual drying progress.
3Productivity
If compressor speed is increased to reduce drying time, then productivity is improved, but energy consumption increases
Solution Approach 1:
The patent applies dynamics by transitioning from a fixed-speed compressor to a variable-speed compressor that dynamically adjusts its rotation speed based on real-time detection of moisture levels in the laundry. The control unit modifies compressor speed according to the amount of water removed during different time intervals, enabling the system to adapt to changing drying conditions and optimize energy consumption throughout the drying cycle.
Solution Approach 2:
The patent applies parameter changes by dynamically adjusting the compressor's rotation speed parameter based on detected drying progress. The system changes operational parameters (compressor speed) in response to varying moisture levels, allowing optimization of both drying time and energy consumption by matching compressor performance to actual drying needs at each stage of the cycle.
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 results in additional energy savings and reduced drying cycle time compared to traditional methods, optimizing the drying process by dynamically adjusting compressor power in response to changing moisture levels.
Implementation Method 1
a first heat exchanger for a thermal coupling between the drying air circuit and the refrigerant circuit wherein the temperature of the drying air increases and the temperature of the refrigerant decreases
Implementation Method 2
a second heat exchanger for a further thermal coupling between the drying air circuit and the refrigerant circuit wherein the temperature of the drying air decreases and the temperature of the refrigerant increases
Data Source
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AI summary
The present invention relates to a method for controlling a drying cycle in a laundry drying machine (1) of the type comprising a heat pump system (20) having a refrigerant circuit (30) for a refrigerant and comprising a drying air circuit (10) for conveying a volume flow of drying air (A) in a laundry drum (9) suitable for receiving laundry to be dried. The refrigerant circuit (30) comprises: a compressor (24) with a variable rotation speed (Cs); a first heat exchanger (21) for a thermal coupling between the drying air circuit (10) and the refrigerant circuit (30) and a second heat exchanger (23) for a further thermal coupling between the drying air circuit (10) and the refrigerant circuit (30). The method comprises an optimization procedure comprising the step of controlling the rotation speed (Cs) or the power (Cp) of the compressor (24) during a plurality of time intervals (Δtn-2; Δtn-1-; Δtn) of the drying cycle. The optimization procedure comprises the steps of: determining an efficiency parameter (F(tn-1)) related to the amount of water removed from the laundry during a first time interval (Δtn-2); determining an efficiency parameter (F(tn)) related to the amount of water removed from the laundry during a second time interval (Δtn-1); comparing the efficiency parameter (F(tn)) determined during the second time interval (Δtn-t) with the efficiency parameter (F(tn-1)) determined during the first time interval (Δtn-2); adjusting the rotation speed (Cs) or the power (CP) of the compressor (24) in a third time interval (Δtn) according to the result of said comparison.