Heat Medium Circuit Venting for Flammable Refrigerant Leaks

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Solution Overview

Problem

Existing heat medium circulation systems fail to safely disperse flammable refrigerants that leak into the heat medium circuit, posing safety risks.

Innovation Solution

A heat medium circulation system is designed with a refrigerant circuit using flammable refrigerants, incorporating a control device, a deaerating device to discharge gases outside, and shut-off valves to stop heat medium flow when leaks are detected, ensuring safe discharge of flammable refrigerants into the atmosphere.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If flammable refrigerant is used in the refrigerant circuit, then cooling/heating efficiency is improved, but safety risk increases due to potential ignition

Engineering Contradiction:
Improvecooling/heating efficiencyVSAvoidignition risk
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts the harmful element (flammable refrigerant) from the heat medium circuit by providing a separate refrigerant circuit. The refrigerant circuit uses flammable refrigerant for efficient cooling/heating, while the heat medium circuit uses non-flammable heat medium, thus eliminating ignition risk in the heat medium circuit while maintaining productivity benefits.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a heat exchanger as an intermediary component that transfers thermal energy between the refrigerant circuit and heat medium circuit without direct contact between flammable refrigerant and heat medium. This mediator enables efficient heat transfer while preventing harmful interactions.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If refrigerant discharge valve is placed outside the casing, then safety is improved by preventing ignition inside casing, but device complexity increases

Engineering Contradiction:
Improveignition preventionVSAvoidvalve placement complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent segments the system into distinct functional zones: the refrigerant circuit (with flammable refrigerant) and the heat medium circuit (with non-flammable heat medium). By placing the refrigerant discharge valve in the refrigerant circuit outside the casing, the system separates hazardous components from the main enclosed space, reducing ignition risk while maintaining manageable complexity through clear functional segmentation.

Inventive Principle:
Principle #1Segmentation

3Object-affected harmful factors

If heat medium circuit includes deaerating device and shut-off valves, then safety is improved by dispersing leaked refrigerant, but device complexity increases

Engineering Contradiction:
Improverefrigerant leakage safetyVSAvoidcircuit component complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent incorporates a deaerating device and shut-off valves in the heat medium circuit as preliminary safety measures. The deaerating device removes air and potential refrigerant leaks from the circuit proactively, while shut-off valves can quickly isolate sections of the circuit upon detecting leakage. These components prepare the system in advance to handle refrigerant leaks safely, reducing harmful effects before they can cause ignition.

Inventive Principle:
Principle #10Preliminary action

4Object-affected harmful factors

If heating device is placed downstream and at higher position than circulation device, then refrigerant dispersion is improved, but device complexity increases

Engineering Contradiction:
Improverefrigerant dispersionVSAvoidcomponent arrangement complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent arranges the heating device at a higher vertical position than the circulation device, utilizing the vertical dimension to improve refrigerant dispersion. This spatial arrangement allows heated refrigerant to rise naturally and disperse more effectively in the upper portions of the circuit, enhancing safety through improved dispersion while adding only minimal complexity through vertical positioning.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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

The system effectively and safely discharges flammable refrigerants into the outside atmosphere, enhancing safety and preventing potential ignition risks.

Implementation Method 1

a heating device for electrically heating the heat medium

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

a deaerating device which separates gas in the heat medium circuit and discharges the gas to outside

Methodology Applied
Scientific EffectBuoyancy: Archimedes' Principle (Buoyancy)

Data Source

PatentEP4075078A1Heat medium circulation system
Publication Date: 2022.10.19 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP4075078A1 patent drawingFigure 1
  • EP4075078A1 patent drawingFigure 2
  • EP4075078A1 patent drawingFigure 3

AI summary

[Object] The present disclosure provides a heat medium circulation system which safely disperses leaked refrigerant to outside atmosphere and which further enhances safety. [Solving Means] A heat medium circulation system 100 in the present disclosure includes: a refrigerant circuit 110 which is formed by annularly connecting a compressor 111, a use-side heat exchanger 112, an expander 113 and a heat source-side heat exchanger 114 to one another; a heat medium circuit 120 through which heat medium cooled or heated by the use-side heat exchanger 112 by means of refrigerant discharged from the compressor 111 circulates; and a control device 130, in which the heat medium circuit 120 is provided therein at least with a circulation device through which the heat medium circulates, a heating device 127 for electrically heating the heat medium, and a deaerating device 128 which discharges the circulating gas in the heat medium circuit 120 to outside the heat medium circuit 120. The heat medium circulation system 100 uses flammable refrigerant. The heating device 127 is placed downstream of the circulation device and on a side higher than the circulation device, and the deaerating device 128 is placed downstream of the heating device 127 and on a side higher than the heating device 127.