Enhanced economy refrigeration control system

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Solution Overview

Problem

Conventional transport refrigeration systems lack advanced control modes to efficiently manage energy consumption and maintain precise temperature control, especially under varying load conditions and energy-saving requirements.

Innovation Solution

A refrigeration system with a controller that alternates between two modes: an energy efficiency mode with lower power consumption and a compensation mode that maintains a tighter temperature range, switching between these modes based on cumulative average temperature thresholds to ensure the temperature remains within a target range around a setpoint.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the refrigeration system operates in temperature control mode with the refrigerant compressor running at lower capacity, then energy consumption is reduced, but temperature control precision deteriorates

Engineering Contradiction:
Improveenergy consumptionVSAvoidtemperature control precision
Core Design Contradiction:
Use of energy by moving objectVSMeasurement precision

Solution Approach 1:

The system dynamically switches between economy mode and temperature control mode based on whether the cargo temperature is within the acceptable range. When temperature is within range, the system operates in economy mode with reduced compressor capacity to save energy. When temperature deviates, it switches to temperature control mode with full compressor capacity to restore proper temperature, creating a dynamic adaptation to operating conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The refrigeration system employs periodic cycling between different operating modes. The controller periodically monitors cargo temperature and alternates between economy mode (lower energy consumption) and temperature control mode (higher precision) based on temperature deviations, creating a periodic action pattern that balances energy efficiency with temperature maintenance.

Inventive Principle:
Principle #19Periodic action

2Measurement precision

If the refrigerant compressor operates at full capacity to maintain precise temperature control, then temperature control precision is improved, but energy consumption increases

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

Solution Approach 1:

The system dynamically adjusts compressor operation based on temperature conditions. Instead of continuous full-capacity operation, the compressor operates at full capacity only when temperature deviations occur (temperature control mode), and at reduced capacity or idle state when temperature is within acceptable range (economy mode), creating a dynamic response that eliminates unnecessary energy consumption.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the operating parameters of the refrigeration system based on temperature conditions. The controller modifies compressor capacity, fan speeds, and cycle timing parameters dynamically - using full capacity parameters only when temperature control is needed, and relaxed parameters when temperature is stable, thereby optimizing the balance between precision and energy consumption.

Inventive Principle:
Principle #35Parameter changes

3Use of energy by moving object

If the system uses economy mode with lower power consumption, then energy efficiency is improved, but temperature stability deteriorates

Engineering Contradiction:
Improvepower consumptionVSAvoidtemperature stability
Core Design Contradiction:
Use of energy by moving objectVSStability of the object's composition

Solution Approach 1:

The system employs feedback control where the controller continuously monitors cargo temperature and uses this information to determine when to switch between economy mode and temperature control mode. The feedback mechanism ensures that temperature stability is maintained by triggering temperature control mode when deviations occur, while allowing economy mode operation when temperature remains stable within the acceptable range.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically transitions between operational states based on real-time temperature conditions. The economy mode provides relaxed operation with lower power consumption when temperature stability is already achieved, while the ability to dynamically switch to temperature control mode ensures stability is restored if deviations occur, creating a dynamic balance between energy efficiency and stability maintenance.

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 reduces energy consumption while maintaining precise temperature control, allowing the system to oscillate around a setpoint temperature and correct deviations, providing significant energy savings while ensuring the cumulative average temperature is within a tightly constrained target range.

Implementation Method 1

Air or an air / gas mixture or other gas is drawn from the interior volume of the trailer by means of the evaporator fan(s) associated with the evaporator, passed through the airside of the evaporator in heat exchange relationship with refrigerant whereby the refrigerant absorbs heat from the air, thereby cooling the air.

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP2702339B1Enhanced economy refrigeration control system
Publication Date: 2019.10.23 CARRIER CORP
  • EP2702339B1 patent drawingFigure 1
  • EP2702339B1 patent drawingFigure 2
  • EP2702339B1 patent drawingFigure 3

AI summary

A controller for controlling a refrigeration unit, a method, and a refrigeration system are disclosed. In an illustrative embodiment, a controller stores instructions for a first refrigeration setting and a second refrigeration setting, tracks a cumulative average temperature in a refrigeration element, and activates either the first refrigeration setting or the second refrigeration setting. The first refrigeration setting has a lower average power consumption and a higher range of temperature variation than the second refrigeration setting. The controller activates the first refrigeration setting until the cumulative average temperature goes outside a selected temperature range; then the controller activates the second refrigeration setting until the cumulative average temperature is within a target temperature range that has a lower threshold that is greater than the lower threshold of the selected temperature range and an upper threshold that is less than the upper threshold of the selected temperature range.