Refrigeration cycle system

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing refrigeration cycle systems fail to prevent the local concentration of leaked refrigerant, which can lead to safety hazards due to the accumulation of flammable gases.

Innovation Solution

A refrigeration cycle system with multiple indoor units and refrigerant leakage detection devices, where a controller increases the air flow rate from the nearest indoor unit to the leakage location and directs air from other units to agitate and diffuse the leaked refrigerant, preventing its concentration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If refrigerant leakage detection devices and control systems are installed to detect and respond to refrigerant leaks, then safety against flammable gas accumulation is improved, but device complexity and cost increase

Engineering Contradiction:
Improvesafety against flammable gas accumulationVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The indoor units perform multiple functions: normal air conditioning operation and refrigerant leakage response. The controller integrates both HVAC control and leakage response coordination, making the existing system infrastructure serve dual purposes rather than adding dedicated separate systems for leakage detection and response.

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

Solution Approach 2:

The system uses its own operational components (air blowing functions, existing sensors, controller) to respond to leakage events. Rather than introducing external specialized equipment, the refrigeration cycle system leverages its existing capabilities to detect, respond to, and mitigate leakage situations through coordinated control of its internal components.

Inventive Principle:
Principle #25Self-service

2Object-affected harmful factors

If air flow rate from indoor units is increased to diffuse leaked refrigerant, then the concentration of leaked refrigerant is inhibited from locally increasing, but energy consumption increases

Engineering Contradiction:
Improverefrigerant concentration localizationVSAvoidenergy consumption
Core Design Contradiction:
Object-affected harmful factorsVSUse of energy by moving object

Solution Approach 1:

The high flow rate air blowing is implemented as a temporary emergency measure only during detected leakage events, not as continuous operation. The controller activates the increased air flow specifically when leakage is detected and maintains it only for the duration necessary to diffuse the leaked refrigerant, thereby limiting energy consumption to the essential emergency response period.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system directs air flow specifically toward the leakage location identified by the detection devices, rather than uniformly increasing air flow throughout the entire system. This targeted approach concentrates the diffusion effort where it is most needed, maximizing the effectiveness of the energy expended in diffusing refrigerant at the critical leakage point.

Inventive Principle:
Principle #3Local quality

3Productivity

If the flow rate of air is increased from the nearest indoor unit to the leakage location, then the refrigerant diffusion efficiency is improved, but the device operation complexity increases

Engineering Contradiction:
Improverefrigerant diffusion efficiencyVSAvoidcontrol operation complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The controller continuously monitors detection device outputs and uses this feedback to dynamically adjust air flow rates and directions. When leakage is detected, the system receives real-time information about leakage location and concentration, automatically adjusting the nearest indoor unit's air flow to maximize diffusion efficiency without requiring manual intervention or complex external control systems.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system pre-configures the control logic and response protocols before leakage events occur. The controller is programmed with predetermined response strategies that automatically execute when leakage is detected, eliminating the need for complex real-time decision-making during emergencies. The air flow control parameters and diffusion patterns are established in advance, simplifying the operational complexity during actual leakage events.

Inventive Principle:
Principle #10Preliminary action

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

Effectively inhibits the local concentration of leaked refrigerant, enhancing safety by diffusing it and reducing the risk of flammable gas accumulation.

Implementation Method 1

the controller increases a flow rate of air sent from the indoor unit closest to the refrigerant leakage detection device that detects the leakage of the refrigerant

Methodology Applied
Scientific EffectAir flow:

Implementation Method 2

the controller is configured to direct a flow of air sent from at least one of the plurality of indoor units other than the one of the plurality of indoor units closest to the one of the plurality of refrigerant leakage detection devices that detects the leakage of the refrigerant, toward the one of the plurality of indoor units closest to the one of the plurality of refrigerant leakage detection devices that detects the leakage of the refrigerant

Methodology Applied
Scientific EffectDiffusion: Diffusion

Data Source

PatentEP3318823B1Refrigeration cycle system
Publication Date: 2020.10.28 MITSUBISHI ELECTRIC CORP
  • EP3318823B1 patent drawingFigure 1
  • EP3318823B1 patent drawingFigure 2
  • EP3318823B1 patent drawingFigure 3

AI summary

A refrigeration cycle system includes a plurality of indoor units installed in an indoor space, a plurality of refrigerant leakage detection devices installed in the indoor space, and a controller. When the refrigerant leakage detection device detects leakage of refrigerant, the controller is configured to increase a flow rate of air sent from the indoor unit closest to the refrigerant leakage detection device that detects the leakage of the refrigerant.