Backup CO2 Cooling System for Cold Room Refrigeration Failures

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Solution Overview

Problem

Mechanical refrigeration systems in cold rooms are prone to breakdowns, leading to potential losses of perishable products due to delayed maintenance and the lack of a reliable backup system, especially in industries like fast food where quick intervention is crucial.

Innovation Solution

A backup system utilizing stored CO2 for carbonation purposes is integrated into the cold room, which can be automatically or manually triggered to maintain the desired temperature by supplying liquid CO2 to a secondary evaporator, regulating CO2 flow and pressure, and including safety elements to prevent excessive pressure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a backup mechanical refrigeration system is installed to prevent breakdowns, then reliability is improved, but device complexity and cost increase significantly

Engineering Contradiction:
ImprovereliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The CO2 storage system, originally designed for carbonation purposes, is made to serve dual functions: (1) carbonation of beverages as per its primary design, and (2) emergency refrigeration backup by evaporating liquid CO2 in the cold room when the mechanical refrigeration system fails. This multi-functionality eliminates the need for a dedicated backup refrigeration system, thereby maintaining reliability while avoiding additional device complexity and cost.

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

Solution Approach 2:

The system utilizes the CO2 already present on-site for carbonation to automatically serve as a backup refrigeration resource. When the mechanical refrigeration system breaks down, the control system automatically triggers the evaporation of liquid CO2 from the existing storage tank into the cold room, allowing the system to self-rescue without requiring external intervention or a separate backup infrastructure.

Inventive Principle:
Principle #25Self-service

2Ease of manufacture

If CO2 storage is used for backup refrigeration, then cost is reduced, but control precision and CO2 conservation become challenging

Engineering Contradiction:
ImprovecostVSAvoidcontrol precision
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The control system continuously monitors the temperature inside the cold room and the state of the mechanical refrigeration system. When a breakdown is detected or temperature rises above the threshold, the system automatically activates the CO2 evaporation process. The feedback loop ensures that CO2 is released only when necessary and stops when the desired temperature is restored, thereby achieving precise control and conserving CO2 for its primary carbonation use while maintaining cost-effectiveness.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

Instead of continuously evaporating CO2 or installing a full-capacity backup refrigeration system, the invention employs partial action by releasing CO2 only to the extent necessary to maintain the cold room temperature during emergency situations. This controlled partial deployment of CO2 reserves achieves adequate temperature maintenance while preserving CO2 for normal operations, balancing cost-effectiveness with control precision.

Inventive Principle:
Principle #16Partial or excessive action

3Temperature

If liquid CO2 is evaporated to cool the cold room, then temperature control is improved during breakdowns, but pressure management and safety risks increase

Engineering Contradiction:
Improvetemperature controlVSAvoidpressure management
Core Design Contradiction:
TemperatureVSObject-affected harmful factors

Solution Approach 1:

An intermediary evaporation system is introduced between the liquid CO2 storage tank and the cold room environment. This intermediary system includes controlled evaporation chambers and distribution mechanisms that gradually vaporize CO2 and regulate its release into the cold room. This intermediary structure prevents sudden pressure surges and uncontrolled CO2 release, thereby achieving effective temperature control while managing pressure safety risks.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system incorporates safety mechanisms and pressure regulation devices in advance to cushion against potential pressure hazards. Before CO2 evaporation is activated, the system ensures that pressure relief valves, flow control mechanisms, and safety interlocks are in place to prevent excessive pressure buildup. This beforehand cushioning approach allows the system to exploit the refrigeration effect of CO2 evaporation while pre-mitigating the associated pressure management risks.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 solution provides a cost-effective and efficient means to maintain the cold room temperature during mechanical refrigeration failures, minimizing product loss and conserving CO2 for its primary use, with the ability to operate for several hours if necessary.

Implementation Method 1

supplying liquid CO2 to a secondary evaporator

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 2

which, through evaporation, produces a refrigerating effect

Methodology Applied
Scientific EffectHeat absorption: Evaporation

Data Source

PatentEP2150758B1Backup co2 cooling system
Publication Date: 2019.01.23 LAIR LIQUIDE SA POUR LETUDE & LEXPLOITATION DES PROCEDES GEORGES CLAUDE
  • EP2150758B1 patent drawingFigure 1~2

AI summary

This invention relates to a backup cooling system for a user site possessing at least one cold chamber for preserving foodstuffs or perishable products, the cold chamber being cooled by a mechanical cooling system, the user site being provided with a liquid CO2 tank used on site for a primary utilization, and the backup device comprising the following elements:- a liquid CO2 evaporation unit positioned in the cold chamber and comprising an evaporator, which is a second evaporator independent of the evaporator of the mechanical cooling system; - a line which supplies said second evaporator of the evaporation unit from said liquid CO2 tank; a discharge out of the chamber for the CO2 vaporized in said second evaporator; - a means for acquiring at least one data item representing the operation or non-operation of the mechanical cooling system; and - a data acquisition and processing system for capturing said representative data item or items and commanding the supply of CO2 to said second evaporator from said tank when the captured data item represents non-operation of the mechanical cooling system.