Method and control system for a refrigeration system and refrigeration appliance

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Solution Overview

Problem

Current refrigeration systems with multiple compartments using a compressor with multiple suction lines lack independent temperature control, leading to temperature variations in unaffected compartments due to external disturbances, as existing control methods fail to isolate control actions to the compartment experiencing the disturbance.

Innovation Solution

A control method and system that models a single compressor with multiple suction lines as multiple independent virtual compressors, allowing each compartment to be controlled independently by establishing reference temperatures, defining error rates, and adjusting compressor rotation and valve opening times for each suction line, thereby preventing temperature crossover between compartments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single compressor with multiple suction lines is used to cool multiple compartments, then the system structure is simplified and cost is reduced, but independent temperature control of each compartment is lost and temperature disturbances propagate between compartments

Engineering Contradiction:
Improvecompressor structureVSAvoidtemperature control independence
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent segments the control of the single compressor by creating multiple independent control loops, one for each compartment. Each control loop independently adjusts the suction valve opening degree and compressor rotation speed based on its own temperature feedback, effectively dividing the unified compressor control into compartment-specific control segments. This allows the physical compressor to function as multiple virtual compressors, achieving independent temperature control for each compartment while maintaining the simplified single-compressor structure.

Inventive Principle:
Principle #1Segmentation

2Temperature

If the compressor rotation and valve opening are controlled based on temperature in one compartment, then the temperature of that compartment is adjusted, but the temperature of other compartments is also affected

Engineering Contradiction:
Improvechiller compartment temperatureVSAvoidtemperature disturbance propagation
Core Design Contradiction:
TemperatureVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by making each compartment's control loop independent and localized. Each control loop uses its own temperature sensor feedback and adjusts control parameters (valve opening degree, rotation speed) specifically for its associated compartment. This localized control approach ensures that temperature corrections in one compartment do not propagate to other compartments, as each loop responds only to local temperature conditions and adjusts its own control actions independently.

Inventive Principle:
Principle #3Local quality

3Adaptability or versatility

If a single compressor serves multiple suction lines, then the system is more compact and economical, but the ability to respond to disturbances in individual compartments independently is compromised

Engineering Contradiction:
Improvesystem configurationVSAvoidindependent control response
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent implements dynamic control by continuously adjusting the suction valve opening degree and compressor rotation speed in real-time based on temperature feedback from each compartment. The control loops dynamically modify operating parameters to respond to changing thermal conditions in each compartment independently. This dynamic adjustment capability allows the single compressor to adapt its performance characteristics for each suction line, effectively responding to disturbances in individual compartments without affecting others, despite the shared mechanical structure.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3620731A1Method and control system for a refrigeration system and refrigeration appliance
Publication Date: 2020.03.11 NIDEC GLOBAL APPLIANCE BRASIL LTDA
  • EP3620731A1 patent drawingFigure 1~2
  • EP3620731A1 patent drawingFigure 3
  • EP3620731A1 patent drawingFigure 4

AI summary

A control method for a refrigeration system (100), with the refrigeration system (100) comprising: at least one compressor associated with at least one pair of suction lines (L1, L2), with each of the suction lines (L1, L2) respectively associated with at least one refrigerated environment (C1, C2), wherein the method comprises the steps of: generating equivalent compressors (1',1'') for each suction line (L1, L2), with the equivalent compressors (1',1'') comprising at least one control parameter associated with each of the refrigerated environments (C1, C2), wherein the equivalent compressors are independent of each other.