Heat Pump Dryer Expander Control for Steady-State Energy Efficiency

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Solution Overview

Problem

The heat pump system in clothes treating apparatuses, such as dryers, faces challenges in maintaining a steady state during the drying process, leading to inefficiencies in energy usage and potential damage from excessive heat transmission.

Innovation Solution

The system controls the refrigerant flow by adjusting the open degree of a variable expander, monitoring temperature differences and humidity levels to optimize heat transfer and prevent overheating, thereby maintaining a stable state and enhancing energy efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the heat pump system operates without continuous monitoring, then the system structure is simpler, but the system cannot maintain a steady state and energy efficiency deteriorates

Engineering Contradiction:
Improvesteady state maintenanceVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements a control unit that continuously monitors the heat pump system's operation state by detecting temperatures at various points (evaporator inlet/outlet, condenser inlet/outlet) and uses this feedback information to adjust the expander's open degree, thereby maintaining the system in a steady state and improving reliability

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces complex mechanical monitoring systems with a control unit that uses temperature sensors and computational logic to detect system state and control the expander, simplifying the overall device complexity while achieving reliable steady state maintenance

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

2Reliability

If the expander open degree is not adjusted, then the control system is simpler, but excessive heat transmission damages the system

Engineering Contradiction:
Improvesystem protectionVSAvoidcontrol system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The control unit continuously monitors temperatures at the evaporator outlet and condenser inlet, and when the temperature difference exceeds a predetermined threshold indicating excessive heat transmission, it automatically adjusts the expander's open degree to reduce heat transmission and protect the system

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system proactively detects temperature differences before excessive heat transmission causes damage, and preemptively adjusts the expander open degree to prevent harmful effects, embodying the preliminary anti-action principle

Inventive Principle:
Principle #9Preliminary anti-action

3Use of energy by moving object

If the refrigerant flow is not optimized, then the system operation is simpler, but energy efficiency decreases

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

Solution Approach 1:

The control unit monitors temperatures at the evaporator outlet and condenser inlet, calculates the temperature difference, and uses this feedback to dynamically adjust the expander's open degree, optimizing refrigerant flow and maximizing energy efficiency during the drying process

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent implements dynamic control of the expander's open degree based on real-time temperature differences, allowing the refrigerant flow to be continuously optimized according to the drying process requirements, thereby improving energy efficiency

Inventive Principle:
Principle #15Dynamics

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 allows for rapid detection and correction of abnormal states, improving system reliability and energy efficiency by adjusting the expander's open degree based on the drying process's progress and humidity levels.

Implementation Method 1

the heat pump system transmits thermal energy to a refrigerant through the evaporator

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 2

transmits thermal energy of the refrigerant to air introduced into the drum through the condenser, thereby generating hot blast

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 3

capable of enhancing the energy efficiency by collecting energy of exhausted hot blast and by re-using the energy to heat air supplied into the drum

Methodology Applied
Scientific EffectHeat recovery: Heat Exchanger

Data Source

PatentEP2719820B1Clothes treating apparatus with heat pump system and operating method thereof
Publication Date: 2022.11.02 LG ELECTRONICS INC
  • EP2719820B1 patent drawingFigure 1~2
  • EP2719820B1 patent drawingFigure 3
  • EP2719820B1 patent drawingFigure 4~5

AI summary

A method for operating a clothes treating apparatus comprising a drum (110) configured to accommodate therein an object to be dried; an air suction means (120) configured to form a flow path of air introduced into the drum; an air exhaustion means (140) configured to form a flow path of air exhausted from the drum; a condenser (130) disposed to heat air sucked into the drum through the air suction means; an evaporator (135) disposed to cool air exhausted from the drum through the air exhaustion means; a compressor (150)configured to compress a refrigerant introduced from the evaporator; and a variable expander (160) configured to expand a refrigerant introduced from the condenser, and having a variable open degree, the method comprising detecting a humidity of exhaust air exhausted from the drum; and changing an open degree of the variable expander according to the detected humidity of the exhaust air, wherein in the step of changing the open degree of the variable expander, an open degree change width is differently determined according to the detected humidity of the exhaust air.