Double-Suction Compressor Control for Precise Multi-Evaporator Cooling

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Solution Overview

Problem

Existing double suction compressors in refrigeration systems face challenges in efficiently managing temperature control and cost efficiency due to limitations in control complexity and configuration, leading to overprotection of components and suboptimal performance across different refrigeration demands.

Innovation Solution

A system and method for controlling a double suction compressor that utilizes various configurations of temperature sensors, actuators, and controllers to dynamically adjust the duty cycle and capacity of each suction line, allowing for precise temperature control and efficient operation across different complexity levels, from low to high complexity systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If conventional fixed capacity compressors with simple ON-OFF control are used, then device complexity is reduced and cost is lowered, but temperature control precision and energy efficiency deteriorate

Engineering Contradiction:
Improvecontrol system complexityVSAvoidtemperature control precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The compressor is divided into two independent suction lines (first and second suction lines) that can be controlled separately. Each suction line has its own control valve and can be independently switched on and off, allowing selective operation based on different refrigeration demands. This segmentation enables precise temperature control in different evaporators while maintaining relatively simple control logic.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The control system dynamically switches between different operating modes: single suction line mode, double suction line mode, and intermediate modes. The switching is based on real-time temperature feedback from evaporators and compressor load conditions, allowing the system to adapt to changing refrigeration demands and optimize energy efficiency.

Inventive Principle:
Principle #15Dynamics

2Measurement precision

If double suction compressors with multiple control configurations are implemented, then temperature control precision and energy efficiency are improved, but device complexity and cost increase

Engineering Contradiction:
Improvetemperature control precisionVSAvoidcontrol system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The control system is designed to handle multiple operating scenarios using a unified control architecture. The same controller manages both single and double suction line operations, accommodates different refrigeration demands, and adapts to varying load conditions. This multi-functionality reduces the need for separate control systems for different operating modes.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The control system automatically determines the optimal operating mode based on temperature feedback from evaporators and compressor load conditions. The controller self-adjusts the suction line configuration without requiring manual intervention or complex external control systems, simplifying the overall device architecture while maintaining precise temperature control.

Inventive Principle:
Principle #25Self-service

3Device complexity

If single suction line operation is used, then device complexity is minimized, but adaptability to different refrigeration demands deteriorates

Engineering Contradiction:
Improvecontrol system complexityVSAvoidadaptability to refrigeration demands
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The system dynamically switches between single and double suction line configurations based on real-time refrigeration demands. When only one evaporator requires cooling or when load conditions favor single-line operation, the system operates in single suction mode. When both evaporators require cooling or when load conditions improve efficiency, the system switches to double suction mode, providing adaptability without permanent complexity.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2650624B1Methods for controlling double-suction line compressors for refrigeration systems
Publication Date: 2018.10.03 WHIRPOOL SA
  • EP2650624B1 patent drawingFigure 1
  • EP2650624B1 patent drawingFigure 2(a)~2(b)
  • EP2650624B1 patent drawingFigure 3~4

AI summary

The present invention refers to methods for controlling a double suction compressor for application in refrigeration systems, capable of meeting the different demands for cost, efficiency and control of temperatures by means of techniques of complexity levels and different configurations of the elements from the control loop (temperature sensors, actuators, controllers, etc.). The proposed solutions include the description of a method for controlling and adjusting the refrigeration capacities of a refrigeration system equipped with a double suction compressor, the refrigeration system comprising compartments to be refrigerated and comprising at least two evaporators (20) positioned in the compartments to be refrigerated (60,70), the double suction compressor (10) being controllable to alternate its compression capacity, the method comprising steps of (i) Continuously measuring at least a temperature coming from a temperature sensor (SET,SCT) associated with at least one of the evaporators (20) and (ii) acting in the compressor's (10) compression capacity, from the measurement of step (i).