Dual-Compressor Refrigeration Control for Fewer Start-Stop Cycles

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Solution Overview

Problem

Existing refrigerating apparatuses with two refrigerant circuits face challenges in accurately controlling internal temperature while minimizing the number of compressor activations, leading to increased power consumption and reduced component lifespan due to frequent compressor operations.

Innovation Solution

The apparatus employs a microcomputer-controlled system that alternates between two-compressor and one-compressor operations based on detected temperature changes, using a flag system to identify which compressor is operational and which is at rest, thereby optimizing compressor usage and reducing activation frequency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the frequency of compressor operation is increased to maintain accurate temperature control, then temperature control accuracy is improved, but power consumption increases and component lifespan decreases

Engineering Contradiction:
Improvetemperature control accuracyVSAvoidpower consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The system implements periodic alternating operation of two compressors, switching between them based on operational cycles rather than continuous operation. This periodic action reduces the activation frequency of each individual compressor while maintaining overall cooling capacity, thereby reducing power consumption and extending component lifespan while preserving temperature control accuracy.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The cooling function is segmented into two separate compressor units that operate alternately. Instead of one compressor working continuously, the system divides the workload between two compressors, allowing each to rest periodically. This segmentation enables reduced activation frequency for each compressor while maintaining the required cooling performance.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If the frequency of compressor operation is increased to maintain accurate temperature control, then temperature control accuracy is improved, but component lifespan decreases

Engineering Contradiction:
Improvetemperature control accuracyVSAvoidcomponent lifespan
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The system implements periodic alternating operation of two compressors, switching between them based on operational cycles rather than continuous operation. This periodic action reduces the activation frequency of each individual compressor while maintaining overall cooling capacity, thereby reducing power consumption and extending component lifespan while preserving temperature control accuracy.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The cooling function is segmented into two separate compressor units that operate alternately. Instead of one compressor working continuously, the system divides the workload between two compressors, allowing each to rest periodically. This segmentation enables reduced activation frequency for each compressor while maintaining the required cooling performance.

Inventive Principle:
Principle #1Segmentation

3Power

If both compressors operate simultaneously to handle increased internal load, then cooling capacity is improved, but the number of compressor activations increases

Engineering Contradiction:
Improvecooling capacityVSAvoidnumber of compressor activations
Core Design Contradiction:
PowerVSProductivity

Solution Approach 1:

The system implements periodic alternating operation of two compressors, switching between them based on operational cycles rather than continuous operation. This periodic action reduces the activation frequency of each individual compressor while maintaining overall cooling capacity, thereby reducing power consumption and extending component lifespan while preserving temperature control accuracy.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system dynamically adjusts compressor operation modes based on cooling load requirements. When cooling demand is high, both compressors can operate simultaneously; when demand is lower, they operate alternately. This dynamic adjustment optimizes the balance between cooling capacity and compressor activation frequency.

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 effectively maintains accurate internal temperature control while reducing compressor activation frequency, prolonging component lifespan and lowering power consumption.

Implementation Method 1

an internal portion of a cold storage cabinet in thermal contact with the two evaporators in common is cooled

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

the refrigerant discharged from the compressor in each of the two refrigerant circuits is cooled and liquefied by the condenser

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 3

the refrigerant discharged from the compressor in each of the two refrigerant circuits is cooled and liquefied by the condenser

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 4

evaporated by the evaporator after the depressurization by the pressure reducer

Methodology Applied
Scientific EffectDepressurization: Depressurisation

Implementation Method 5

evaporated by the evaporator after the depressurization by the pressure reducer

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP2339264B1Refrigerating device
Publication Date: 2018.04.25 PANASONIC HEALTHCARE HLDG CO LTD
  • EP2339264B1 patent drawingFigure 1
  • EP2339264B1 patent drawingFigure 2
  • EP2339264B1 patent drawingFigure 3

AI summary

A refrigerating apparatus includes a first refrigerant circuit including a first compressor, a first condenser, a first pressure reducer, and a first evaporator, connected circularly with a first refrigerant pipe, a refrigerant discharged from the first compressor being condensed at the first condenser and thereafter evaporated at the first evaporator to acquire a cooling effect; a second refrigerant circuit including a second compressor, a second condenser, a second pressure reducer, and a second evaporator, connected circularly with a second refrigerant pipe, a refrigerant discharged from the second compressor being condensed at the second condenser and thereafter evaporated at the second evaporator to acquire a cooling effect; a temperature sensor that detects a temperature of an internal portion of a cold storage cabinet, the first evaporator and the second evaporator being disposed to cool the internal portion at the same time; and a first control device that controls the first compressor and the second compressor in such a manner that both the first compressor and the second compressor are operated each time the detected temperature of the temperature sensor reaches a first temperature, and controls the first compressor and the second compressor in such a manner that the first compressor and the second compressor are alternately operated each time the detected temperature of the temperature sensor reaches a second temperature that is lower than the first temperature.