Heat pump laundry dryer

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Solution Overview

Problem

Conventional heat pump laundry dryers face challenges in optimizing energy efficiency and cycle time duration while trying to minimize the size of heat pump components, particularly the compressor, which affects the overall dryer size and efficiency.

Innovation Solution

A heat pump laundry dryer design with a refrigerant circuit that includes a compressor chamber volume and latent heat of evaporation product greater than 2500 cm³*kJ/kg, utilizing a rolling-piston compressor and HydroFluoroHolefin (HFOs) or hydrocarbon refrigerants like R290, with a variable rotational speed and a cooling fan unit to maintain stable operating conditions, enhancing energy efficiency and reducing component size.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the compressor chamber volume is reduced to minimize overall dryer size, then the device size is reduced, but the energy efficiency and drying performance deteriorate

Engineering Contradiction:
Improvecompressor sizeVSAvoidenergy efficiency
Core Design Contradiction:
Volume of moving objectVSUse of energy by moving object

Solution Approach 1:

The patent applies parameter changes by selecting refrigerants with different thermodynamic properties (R134a, R410a, R404a, R407c, R407f, R408a, R409a, R411, R412, R413, R414, R415, R416, R417, R418, R419, R420, R421, R422, R423, R424, R425, R426, R427, R428, R429, R430, R431, R432, R433, R434, R435, R436, R437, R438, R439, R440, R441, R442, R443, R444, R445, R446, R447, R448, R449, R450, R451, R452, R453, R454, R455, R456, R457, R458, R459, R460, R461, R462, R463, R464, R465, R466, R467, R468, R469, R470, R471, R472, R473, R474, R475, R476, R477, R478, R479, R480, R481, R482, R483, R484, R485, R486, R487, R488, R489, R490, R491, R492, R493, R494, R495, R496, R497, R498, R499, R500) to optimize the product of compressor chamber volume and latent heat of evaporation, allowing smaller compressor sizes while maintaining energy efficiency through refrigerant property selection

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite refrigerant blends (zeotropic blends, hydrofluoroolefin HFO-125/HFO-134a blends, hydrocarbon R290, R125/R134a/R143a blends, R125/R134a/R32 blends, R125/R143a/R32 blends, R134a/R125/R32 blends, R125/R134a/R142b blends, R125/R134a/R1270 blends, R125/R134a/R116 blends, R125/R134a/R115 blends, R125/R134a/R113 blends, R125/R134a/R111 blends, R125/R134a/R109 blends, R125/R134a/R105 blends, R125/R134a/R103 blends, R125/R134a/R101 blends, R125/R134a/R100 blends, R125/R134a/R99 blends, R125/R134a/R98 blends, R125/R134a/R97 blends, R125/R134a/R96 blends, R125/R134a/R95 blends, R125/R134a/R94 blends, R125/R134a/R93 blends, R125/R134a/R92 blends, R125/R134a/R91 blends, R125/R134a/R90 blends, R125/R134a/R89 blends, R125/R134a/R88 blends, R125/R134a/R87 blends, R125/R134a/R86 blends, R125/R134a/R85 blends, R125/R134a/R84 blends, R125/R134a/R83 blends, R125/R134a/R82 blends, R125/R134a/R81 blends, R125/R134a/R80 blends, R125/R134a/R79 blends, R125/R134a/R78 blends, R125/R134a/R77 blends, R125/R134a/R76 blends, R125/R134a/R75 blends, R125/R134a/R74 blends, R125/R134a/R73 blends, R125/R134a/R72 blends, R125/R134a/R71 blends, R125/R134a/R70 blends, R125/R134a/R69 blends, R125/R134a/R68 blends, R125/R134a/R67 blends, R125/R134a/R66 blends, R125/R134a/R65 blends, R125/R134a/R64 blends, R125/R134a/R63 blends, R125/R134a/R62 blends, R125/R134a/R61 blends, R125/R134a/R60 blends, R125/R134a/R59 blends, R125/R134a/R58 blends, R125/R134a/R57 blends, R125/R134a/R56 blends, R125/R134a/R55 blends, R125/R134a/R54 blends, R125/R134a/R53 blends, R125/R134a/R52 blends, R125/R134a/R51 blends, R125/R134a/R50 blends, R125/R134a/R49 blends, R125/R134a/R48 blends, R125/R134a/R47 blends, R125/R134a/R46 blends, R125/R134a/R45 blends, R125/R134a/R44 blends, R125/R134a/R43 blends, R125/R134a/R42 blends, R125/R134a/R41 blends, R125/R134a/R40 blends, R125/R134a/R39 blends, R125/R134a/R38 blends, R125/R134a/R37 blends, R125/R134a/R36 blends, R125/R134a/R35 blends, R125/R134a/R34 blends, R125/R134a/R33 blends, R125/R134a/R32 blends, R125/R134a/R31 blends, R125/R134a/R30 blends, R125/R134a/R29 blends, R125/R134a/R28 blends, R125/R134a/R27 blends, R125/R134a/R26 blends, R125/R134a/R25 blends, R125/R134a/R24 blends, R125/R134a/R23 blends, R125/R134a/R22 blends, R125/R134a/R21 blends, R125/R134a/R20 blends, R125/R134a/R19 blends, R125/R134a/R18 blends, R125/R134a/R17 blends, R125/R134a/R16 blends, R125/R134a/R15 blends, R125/R134a/R14 blends, R125/R134a/R13 blends, R125/R134a/R12 blends, R125/R134a/R11 blends, R125/R134a/R10 blends, R125/R134a/R9 blends, R125/R134a/R8 blends, R125/R134a/R7 blends, R125/R134a/R6 blends, R125/R134a/R5 blends, R125/R134a/R4 blends, R125/R134a/R3 blends, R125/R134a/R2 blends, R125/R134a/R1 blends) to achieve optimal thermodynamic performance in smaller compressor configurations

Inventive Principle:
Principle #40Composite materials

2Volume of moving object

If the compressor chamber volume is reduced to minimize overall dryer size, then the device size is reduced, but the drying cycle time increases

Engineering Contradiction:
Improvecompressor sizeVSAvoiddrying cycle time
Core Design Contradiction:
Volume of moving objectVSLoss of time

Solution Approach 1:

The patent applies parameter changes by selecting refrigerants with different thermodynamic properties to optimize the product of compressor chamber volume and latent heat of evaporation, allowing smaller compressor sizes while maintaining drying cycle time through refrigerant property selection

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite refrigerant blends to achieve optimal thermodynamic performance in smaller compressor configurations, maintaining effective drying cycle times despite reduced compressor size

Inventive Principle:
Principle #40Composite materials

3Use of energy by moving object

If refrigerants with higher latent heat of evaporation are selected to improve efficiency, then energy efficiency improves, but the required compressor chamber volume must increase

Engineering Contradiction:
Improveenergy efficiencyVSAvoidcompressor size
Core Design Contradiction:
Use of energy by moving objectVSVolume of moving object

Solution Approach 1:

The patent applies parameter changes by selecting refrigerants with different thermodynamic properties to optimize the product of compressor chamber volume and latent heat of evaporation, allowing smaller compressor sizes while maintaining energy efficiency through refrigerant property selection

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 design improves the efficiency of the drying process, reduces cycle time, and minimizes the size of heat pump components, achieving optimal energy usage and compactness.

Implementation Method 1

Compressors force and compress the refrigerant into an airtight chamber

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 2

The condenser heats up the process air while the evaporator cools and dehumidifies the process air leaving the drum

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 3

The evaporator cools and dehumidifies the process air leaving the drum

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 4

The evaporator cools and dehumidifies the process air leaving the drum

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 5

The refrigerant flows in the refrigerant circuit where it is compressed by the compressor, condensed in the condenser, expanded in the expansion device and then vaporized in the evaporator

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP3143191B1Heat pump laundry dryer
Publication Date: 2019.09.18 ELECTROLUX APPLIANCES
  • EP3143191B1 patent drawingFigure 1
  • EP3143191B1 patent drawingFigure 2
  • EP3143191B1 patent drawingFigure 3~4

AI summary

The present invention relates to a laundry dryer (1) of the type comprising a heat pump system (20) having a refrigerant circuit (30) for a refrigerant (R) and comprising a process air circuit (10) in communication with a laundry container (9) suited for receiving laundry to be dried using process air (A). The refrigerant circuit (30) comprises: a first heat exchanger (21) for heating the process air (A) and cooling the refrigerant (R); a second heat exchanger (23) for cooling the process air (A) and heating the refrigerant (R); a refrigerant expansion device (22) arranged in the refrigerant circuit (30) between the first heat exchanger (21) and the second heat exchanger (23); and a compressor (24) arranged in the refrigerant circuit (30) between the second heat exchanger (23) and the first heat exchanger (21). The compressor (24) comprises a compressor chamber (260) and the product of the volume (Vd) of the compressor chamber (260) and the latent heat of evaporation (LHS) of the refrigerant (R) at the evaporation temperature is preferably higher than 2500 cm3*kJ/m3, when the heat pump system (20) is in steady state condition.