Heat Pump Condensation Dryer Cooling for Impermissible State Detection

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Solution Overview

Problem

Condensation dryers with heat pumps face challenges in detecting impermissible operating states, such as high temperatures and air circulation issues, which can lead to refrigerant liquefaction problems and energy inefficiencies, making it difficult to maintain optimal heat pump operation and prevent damage to components.

Innovation Solution

A condensation dryer equipped with a heat pump that includes a temperature sensor to monitor refrigerant temperature, a cooling device with an additional heat exchanger, and a controller to switch on cooling when the refrigerant temperature exceeds a limit, along with a method to evaluate temperature changes and display impermissible operating states using visual and acoustic indicators.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a heat pump is used to reduce energy loss in condensation dryers, then energy efficiency is improved, but the risk of impermissible operating states (high temperature, refrigerant liquefaction) increases

Engineering Contradiction:
Improveenergy lossVSAvoidoperating state stability
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The temperature sensor monitors refrigerant temperature in advance, and the controller activates the cooling device before the refrigerant temperature reaches dangerous levels, preventing impermissible operating states from occurring in the first place

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors refrigerant temperature via the temperature sensor and adjusts the cooling device operation based on real-time temperature data, creating a closed-loop control system that maintains reliable operation while maximizing energy efficiency

Inventive Principle:
Principle #23Feedback

2Device complexity

If refrigerant temperature is not monitored, then device complexity is reduced, but damage to heat pump components may occur

Engineering Contradiction:
Improvemonitoring system complexityVSAvoidcomponent damage risk
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

A temperature sensor is introduced as an intermediary measurement device that indirectly monitors refrigerant temperature without disrupting the refrigerant flow or requiring direct contact with high-pressure refrigerant, thereby protecting components while enabling monitoring

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system replaces complex mechanical temperature monitoring mechanisms with electronic temperature sensors and digital control, simplifying the monitoring system while enabling precise temperature detection and automated response

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

3Temperature

If cooling device is always active, then refrigerant temperature control is improved, but energy consumption increases

Engineering Contradiction:
Improverefrigerant temperature controlVSAvoidenergy consumption
Core Design Contradiction:
TemperatureVSUse of energy by moving object

Solution Approach 1:

The cooling device operates periodically rather than continuously, being activated only when the temperature sensor detects that refrigerant temperature approaches the threshold for impermissible operating states, thereby reducing unnecessary energy consumption while maintaining effective temperature control

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The cooling device operation is dynamically adjusted based on real-time refrigerant temperature conditions, transitioning between active and inactive states as needed to maintain optimal refrigerant temperature without wasting energy during normal operating conditions

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 solution allows for the reliable detection and display of impermissible operating states, ensuring the heat pump operates within optimal conditions, reducing energy loss, and protecting the dryer components, thereby achieving a favorable energy balance and preventing damage.

Implementation Method 1

a temperature sensor for measuring a temperature TK of the refrigerant

Methodology Applied
Scientific EffectTemperature sensing: Thermal Radiation

Implementation Method 2

a cooling device for the heat pump... Additional heat exchangers for cooling the heat pump circuit are arranged in the cooling air duct

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 3

a compressor, a condenser and a throttle... the vaporized, gaseous refrigerant passes via a compressor to the heat source

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 4

where due to Condensation of the gaseous refrigerant releases heat that is used to heat the process air

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 5

the throttle is used to reduce the internal pressure in the refrigerant so that it can evaporate in the evaporator

Methodology Applied
Scientific EffectPressure reduction: Pressure Drop

Implementation Method 6

the refrigerant evaporating in the heat sink... the liquefied refrigerant finally flows back to the evaporator through a restrictor

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP2326762B1Drying method and condensation dryer comprising a heat pump and system for recognizing an unallowable operating state
Publication Date: 2011.12.28 BSH HAUSGERATE GMBH
  • EP2326762B1 patent drawingFigure 1
  • EP2326762B1 patent drawingFigure 2
  • EP2326762B1 patent drawingFigure 3

AI summary

The invention relates to a condensation dryer 1 with a drying chamber 3 for the objects to be dried, a process air circuit 2, a first fan 19 in the process air circuit 12, a heat pump 13, 14, 15, 17 in which a coolant circulates, an evaporator 13, a compressor 14, a condenser 15 and a throttle 17 as well as a temperature sensor 22 for measuring a temperature of the coolant, a cooling device 16, 20 for the heat pump 13, 14, 15, 17 and a controller 10, wherein first means 26 are provided for comparing, by way of a limit temperature T? lim stored in the controller 10, a temperature T? of the coolant measured by the temperature sensor 22, and for operating the cooling device 16, 20 when T? = T? lim for a time period ?t, and second means 27 are provided for evaluating a change of the temperature T? in time period ?t to see if an unallowable operating state exists. The invention further relates to a method for operating the condensation dryer.