Freezing apparatus

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Solution Overview

Problem

Conventional refrigeration systems with multiple compressors face oil imbalances, leading to poor lubrication in some compressors due to uneven distribution of refrigerating machine oil, resulting in operational inefficiencies and potential damage.

Innovation Solution

The system incorporates an oil return passageway that combines refrigerating machine oil from multiple oil separators and distributes it to compressors, using junction and branch injection passageways with valves to manage oil flow and prevent backflow, ensuring balanced oil distribution and operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If one oil separator is provided on the discharge pipe of each compressor and connected through an oil return pipe, then the configuration is simplified, but oil imbalance occurs causing poor lubrication in compressors short of refrigerating machine oil

Engineering Contradiction:
Improveconfiguration complexityVSAvoidlubrication reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent combines the oil return paths of multiple compressors into a common oil return pipe that connects to a single oil separator. This merging allows refrigerating machine oil separated by the oil separator to be distributed to multiple compressors simultaneously, preventing oil imbalance and ensuring reliable lubrication while maintaining configuration simplicity.

Inventive Principle:
Principle #5Merging (Combining)

2Ease of operation

If refrigerating machine oil is returned directly to the specific compressor from which it was discharged, then the oil circulation path is short and simple, but oil imbalance progresses causing shortages in other compressors

Engineering Contradiction:
Improveoil circulation efficiencyVSAvoidrefrigerating machine oil distribution
Core Design Contradiction:
Ease of operationVSQuantity of substance

Solution Approach 1:

The patent introduces a common oil return pipe as an intermediary between the oil separator and multiple compressors. This intermediary structure enables the oil separator to serve as a central distribution point, allowing refrigerating machine oil to be efficiently circulated to all compressors and preventing oil shortages while maintaining circulation efficiency.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If a single oil separator serves multiple compressors through a common oil return pipe, then oil distribution balance is improved, but the system must ensure adequate oil supply during compressor capacity changes and non-operation

Engineering Contradiction:
Improveoil distribution balanceVSAvoidoperation capacity adaptability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent makes the common oil return pipe and oil separator system universal for serving multiple compressors with different operational states. The system can adapt to various scenarios including compressor capacity changes, partial operation, and non-operation by distributing oil through the common return pipe to whichever compressors are operating, ensuring reliable lubrication across different operational configurations.

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

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 configuration reduces oil imbalances, prevents lubrication failures, and maintains system efficiency by ensuring adequate oil supply to all compressors, even during changes in operation capacity and compressor status.

Implementation Method 1

an oil separator provided on a discharge pipe of each of the compressors

Methodology Applied
Scientific EffectOil separation: Centrifugal Separation

Implementation Method 2

only the second pre-junction passageway has a check valve for preventing refrigerating machine oil from flowing from the discharge side into the non-operating second compressor

Methodology Applied
Scientific EffectCheck valve flow control: Valve

Implementation Method 3

configured to perform a refrigeration cycle

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP2258992B1Freezing apparatus
Publication Date: 2019.09.18 DAIKIN INDUSTRIES LTD
  • EP2258992B1 patent drawingFigure 1
  • EP2258992B1 patent drawingFigure 2
  • EP2258992B1 patent drawingFigure 3

AI summary

In a refrigeration system in which a compressor mechanism including a plurality of compressors, oil separators (37a, 37b) are provided at a discharge pipe (56a) of a first compressor (14a) and a discharge pipe (56b) of a second compressor (14b), respectively. An oil return passageway (32) for returning refrigerating machine oil from the oil separators (37a, 37b) to a compressor mechanism (40) is configured to combine streams of refrigerating machine oil separated in the oil separators (37a, 37b) and distribute the combined refrigerating machine oil to the first compressor (14a) and the second compressor (14b).