System and method for controlling a refrigeration unit with multi-compressor configuration

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Solution Overview

Problem

Conventional refrigeration systems with multiple compressors operate all compressors at a uniform speed, leading to inefficiency and increased energy consumption, as they do not account for the individual optimal operating speeds of each compressor, thus compromising overall system efficiency and increasing operational costs.

Innovation Solution

A controller is used to issue a first control signal to operate a first set of compressors at a variable speed is selected based on a selected temperature to operate a second control signal to operate a first set of compressors at a variable speed, where the controller is configured to issue a second control signal to operate a second control signal to operate a second control signal to operate a second set of compressors at a predetermined speed, where the controller is configured to select a second set of compressors at a variable speed to operate a second set of compressors at a variable speed to operate a second set of compressors at a predetermined speed based on real-time cooling capacity and load, and switch between these speeds based on predefined cycles or times.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If all compressors operate at uniform speed, then system simplicity is maintained, but energy consumption increases and system efficiency decreases

Engineering Contradiction:
Improvecontrol system complexityVSAvoidenergy consumption
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The compressor group is segmented into multiple independent compressors, each capable of independent speed control. The controller divides the compressors into different operational categories (first group for variable speed, second group for predetermined speed), allowing differentiated control strategies for different components within the same system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system transitions from static uniform speed operation to dynamic variable speed operation. The first group of compressors operates at variable speeds that can be adjusted in real-time based on cooling load requirements, while the second group operates at predetermined speeds, creating a dynamic control system that adapts to changing conditions.

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If all compressors operate at uniform speed, then control simplicity is maintained, but overall system efficiency is compromised

Engineering Contradiction:
Improvecontrol simplicityVSAvoidsystem efficiency
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The compressor fleet is segmented into two groups with different control strategies. The first group uses variable speed control optimized for part-load conditions, while the second group uses predetermined speed operation, allowing the system to achieve high efficiency across varying load conditions without requiring complex individual control for every compressor.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system changes the operational parameters (speed) of compressors based on loading conditions. During part-load operation, compressors in the first group operate at variable speeds optimized for efficiency. During full-load operation, compressors in the second group operate at predetermined high-speed settings, optimizing system performance for different operational states.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If compressors operate without individual optimal speed selection, then operational simplicity is maintained, but operational costs increase

Engineering Contradiction:
Improveoperational simplicityVSAvoidoperational cost
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

The control system automatically selects which compressors operate at variable speed and which operate at predetermined speed based on real-time cooling load conditions, eliminating the need for manual intervention. The system self-adjusts its operational mode to optimize energy consumption and reduce operational costs without requiring user expertise or manual configuration.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4675209A1System and method for controlling a refrigeration unit with multi-compressor configuration
Publication Date: 2026.01.07 CARRIER CORP
  • EP4675209A1 patent drawingFigure 1
  • EP4675209A1 patent drawingFigure 2
  • EP4675209A1 patent drawingFigure 3

AI summary

Described herein is a system and a method for controlling a refrigeration unit (100A) comprising a plurality of compressors (102). The system comprises a controller (114) connected to the plurality of compressors (102), where the controller (114) comprises a processor (114-1) with access to a memory (114-2) storing instructions executable by the processor (114-2), which causes the controller (114) to issue a first control signal to operate a first set of compressors among the plurality of compressors (102) at a variable speed, wherein the variable speed is selected based on a selected temperature to be maintained in a space (200) by the refrigeration unit (100A), and issue a second control signal to operate a second set of compressors among the plurality of compressors (102) at a predetermined speed.