Refrigeration cycle device

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional refrigeration cycle systems with multiple outdoor units face challenges in maintaining even oil distribution, leading to oil depletion or overfilling issues, which affect compressor reliability and performance, and require cumbersome oil equalizing pipes for installation.

Innovation Solution

A refrigeration cycle apparatus with sensors to detect refrigeration oil levels in each compressor, allowing a controller to adjust operation modes to maintain optimal oil distribution by switching compressor operation and adjusting refrigerant flow rates, eliminating the need for oil equalizing pipes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If oil equalizing pipes are installed to maintain even oil distribution among compressors, then compressor reliability is improved, but installation complexity and cost increase

Engineering Contradiction:
Improvecompressor reliabilityVSAvoidinstallation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention removes the oil equalizing pipes from the system entirely. Instead of adding complex piping infrastructure, the patent uses sensor-based detection and controller-driven operational switching to achieve oil equalization, extracting the unnecessary component while maintaining the desired function.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system enables compressors to self-regulate their oil levels through automated control. The controller monitors oil quantities via sensors and automatically switches operational states between compressors to maintain proper oil distribution, eliminating the need for manual intervention or complex mechanical equalizing systems.

Inventive Principle:
Principle #25Self-service

2Reliability

If fixed-period oil supply control is used in oil equalizing operation, then oil distribution is maintained, but oil equalization may be insufficient under varying environmental and operational conditions

Engineering Contradiction:
Improveoil distribution balanceVSAvoidadaptability to varying conditions
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The invention implements a feedback control system where sensors continuously monitor oil quantities in each compressor, and the controller adjusts operational states based on this real-time information. This closed-loop feedback mechanism enables the system to adapt to varying environmental and operational conditions, maintaining proper oil distribution dynamically rather than relying on fixed periodic control.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system transitions from static, fixed-period oil supply control to dynamic, condition-based operational switching. The controller continuously evaluates sensor data and adjusts compressor operational states in real-time, enabling the system to adapt flexibly to changing conditions while maintaining oil equalization.

Inventive Principle:
Principle #15Dynamics

3Ease of operation

If uniform operation total time control is applied to all compressors, then operational simplicity is maintained, but compressors may experience oil depletion or overfilling affecting performance

Engineering Contradiction:
Improvecontrol simplicityVSAvoidcompressor performance
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The invention applies different operational control strategies to different compressors based on their individual oil quantities and operational states. Rather than uniform control, each compressor's operational state is independently determined by the controller based on sensor feedback, allowing localized optimization of oil distribution while maintaining overall system simplicity.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3546849B1Refrigeration cycle device
Publication Date: 2020.06.03 MITSUBISHI ELECTRIC CORP
  • EP3546849B1 patent drawingFigure 1.
  • EP3546849B1 patent drawingFigure 2
  • EP3546849B1 patent drawingFigure 3

AI summary

A refrigeration cycle apparatus includes a plurality of outdoor units (50a, 50b). Each of the plurality of outdoor units (50a, 50b) includes an outdoor heat exchanger (2a, 2b), a compressor (1a, 1b), and a sensor (5a, 5b) to detect the quantity of refrigeration oil in the outdoor unit. A controller (100) has a first operation mode in which a part of the plurality of outdoor units (50a, 50b) is operated and another outdoor unit is stopped; and a second operation mode in which all of the plurality of outdoor units (50a, 50b) are operated. In the first operation mode, when the operating time of an operating outdoor unit exceeds a prescribed time and the quantity of refrigeration oil in the compressor of the operating outdoor unit is equal to or larger than a prescribed quantity, the controller (100) stops the operating outdoor unit and makes a switch to bring a stopped outdoor unit of the plurality of outdoor units (50a, 50b) into operation.