Refrigeration cycle device

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Solution Overview

Problem

In multi-connected air conditioners with multiple compressors, the oil level fluctuates due to compressor startups and shutdowns, leading to inefficient refrigeration cycles and oil discharge, which affects performance and stability.

Innovation Solution

The refrigeration cycle device connects the gas discharge path of one compressor to the sealed casing of another, utilizing the stopped compressor as an oil separator for the operating compressor, and incorporates a collective type accumulator to manage refrigerant and oil distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the compressor starts and stops repeatedly due to load variation, then the refrigeration cycle can adapt to different loads, but the oil amount in the compressor fluctuates and oil is discharged

Engineering Contradiction:
Improveload adaptationVSAvoidoil level stability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent merges the function of the stopped compressor with an oil separator, creating a combined structure where the stopped compressor's sealed casing serves dual purposes: housing the compression mechanism when active and functioning as an oil separation chamber when inactive. This integration eliminates the need for separate oil management components and stabilizes oil levels during compressor cycling.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The stopped compressor is given multiple functions: it continues to house the compression mechanism for future operation while simultaneously serving as an oil separator for the currently operating compressor. This multi-functionality allows the system to maintain oil stability without adding separate dedicated oil management components for each compressor.

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

2Reliability

If a separate oil separator and complex oil management system are added, then oil level can be controlled, but the device complexity and control complexity increase

Engineering Contradiction:
Improveoil level controlVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The stopped compressor automatically performs oil separation for the operating compressor without requiring external control systems, sensors, or active management. The oil separation occurs passively through the connection between the stopped compressor's sealed casing and the operating compressor's discharge path, eliminating the need for complex control mechanisms while maintaining reliable oil level management.

Inventive Principle:
Principle #25Self-service

3Loss of energy

If the compressor stops at low temperature, then energy is saved, but refrigerant condenses and causes performance reduction and oil discharge upon restart

Engineering Contradiction:
Improveenergy savingVSAvoidrefrigeration cycle performance
Core Design Contradiction:
Loss of energyVSProductivity

Solution Approach 1:

The stopped compressor's sealed casing acts as an intermediary chamber that receives and manages refrigerant from the operating compressor during shutdown periods. This intermediary structure prevents direct condensation in the operating compressor by providing a buffer zone where refrigerant can be managed, thereby maintaining system performance while allowing energy-saving shutdowns.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Temperature

If the stopped compressor is not heated during operation of another compressor, then refrigerant condenses in the stopped compressor, but additional heating components increase device complexity

Engineering Contradiction:
Improvecompressor temperatureVSAvoidheating system complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The stopped compressor self-heats by receiving hot refrigerant discharge from the operating compressor through the connected sealed casing. This passive heating mechanism eliminates the need for active heating components, sensors, or control systems while effectively preventing refrigerant condensation and maintaining ready-to-start conditions in the stopped compressor.

Inventive Principle:
Principle #25Self-service

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 stabilizes oil and refrigerant levels, reduces oil discharge, ensures quick compressor startups, and maintains efficient operation by preventing refrigerant condensation, thereby enhancing the refrigeration cycle's stability and efficiency.

Implementation Method 1

the stopped compressor acts as an oil separator of the operating compressor

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 2

as the operating compressor outputs the refrigerant, the stopped compressor is heated

Methodology Applied
Scientific EffectThermal heating: Heating

Implementation Method 3

the stopped compressor is heated, and the refrigerant in the stopped compressor does not condense

Methodology Applied
Scientific EffectThermal heating: Heating

Data Source

PatentEP3312526B1Refrigeration cycle device
Publication Date: 2026.03.04 GUANGDONG MEIZHI COMPRESSOR
  • EP3312526B1 patent drawingFigure 1~2
  • EP3312526B1 patent drawingFigure 3~4
  • EP3312526B1 patent drawingFigure 5~6

AI summary

A refrigeration cycle device includes at least a condenser, an expansion valve, an evaporator and a plurality of compressors, a sealed casing of each of the compressors is disposed with a rotary compression mechanism part in communication with a low-pressure path and a motor part configured to drive the compression mechanism part, the low-pressure path is in communication with the evaporator, each of the compressors is further provided with an oil storage cavity, and a gas discharge path of at least one compressor is connected with the sealed casing of another compressor.