Refrigeration apparatus

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Solution Overview

Problem

Conventional air conditioners with a single refrigerant cycle are prone to complete refrigerant leakage when damage occurs, leading to increased refrigerant volume loss.

Innovation Solution

The refrigeration apparatus divides the refrigerant circuit into two separate cycles, with a leakage detection sensor and shutoff valves to quickly detect and contain refrigerant leaks, reducing the volume of leaked refrigerant and preventing it from escaping.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single refrigerant cycle circuit is used, then the system structure is simple, but the entire refrigerant may leak from the refrigerant circuit when damage occurs

Engineering Contradiction:
Improverefrigerant circuit structureVSAvoidrefrigerant leakage volume
Core Design Contradiction:
Device complexityVSLoss of substance

Solution Approach 1:

The refrigerant circuit is divided into multiple independent refrigerant cycle circuits (first refrigerant cycle and second refrigerant cycle), each containing its own compressor, condenser, expansion valve, and evaporator. This segmentation ensures that if one circuit experiences damage, the refrigerant leakage is confined to that specific circuit only, preventing total refrigerant loss from the entire system.

Inventive Principle:
Principle #1Segmentation

2Ease of operation

If a single refrigerant cycle circuit is used, then the system is easier to operate, but refrigerant leakage cannot be contained when damage occurs

Engineering Contradiction:
Improvesystem operationVSAvoidrefrigerant leakage volume
Core Design Contradiction:
Ease of operationVSLoss of substance

Solution Approach 1:

The system operates as multiple independent refrigerant cycles that can function separately. When leakage is detected in one circuit through sensors, the system can automatically shut off that specific circuit while maintaining operation of other circuits, thus containing the leakage problem without complete system shutdown.

Inventive Principle:
Principle #1Segmentation

3Loss of substance

If the refrigerant circuit is divided into two separate cycles, then refrigerant leakage volume is reduced, but the device complexity increases

Engineering Contradiction:
Improverefrigerant leakage volumeVSAvoidrefrigerant circuit structure
Core Design Contradiction:
Loss of substanceVSDevice complexity

Solution Approach 1:

The refrigerant circuit is divided into multiple independent refrigerant cycles (first and second cycles), each with its own compressor, condenser, expansion valve, and evaporator. This segmentation ensures that if one circuit experiences damage, the refrigerant leakage is confined to that specific circuit only, preventing total refrigerant loss from the entire system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each refrigerant cycle is designed with universal components that can perform multiple functions - the compressors can operate independently or in coordination, the condensers and evaporators serve both heating and cooling modes, and the expansion valves regulate flow in different operational conditions. This multi-functionality reduces the need for additional specialized components.

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

4Reliability

If leakage detection sensor and shutoff valves are added, then refrigerant leakage can be quickly contained, but the device complexity increases

Engineering Contradiction:
Improveleakage detection and containmentVSAvoidcontrol system structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Leakage detection sensors are pre-installed in each refrigerant cycle circuit to detect refrigerant leakage at early stages. Automatic shutoff valves are pre-positioned at strategic locations in each circuit. When leakage is detected, these valves automatically close to contain the refrigerant, preventing further leakage without requiring manual intervention or complex control algorithms.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system incorporates automatic shutoff valves that self-activate when leakage is detected by sensors, eliminating the need for external control systems or manual operation. The valves automatically close to contain the refrigerant in the affected circuit, providing self-service leakage containment that reduces the complexity of external control mechanisms.

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 effectively reduces refrigerant leakage by dividing the circuit into two cycles, enabling quick detection and containment of leaks, thereby minimizing refrigerant loss and maintaining system integrity.

Implementation Method 1

The leakage detection sensor is the pressure sensor in this configuration. When a refrigerant leaks in the first case having airtightness, refrigerant leakage can be detected in accordance with pressure change.

Methodology Applied
Scientific EffectPressure change detection:

Implementation Method 2

The first case in this configuration includes the rupture disk. The rupture disk is thus destroyed to release abnormally increased pressure in the first case.

Methodology Applied
Scientific EffectPressure release through rupture:

Implementation Method 3

The control unit is cooled by the cooling refrigerant pipe in this configuration. This achieves effective cooling of the control unit that generates heat.

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentEP4027074B1Refrigeration apparatus
Publication Date: 2024.10.23 DAIKIN INDUSTRIES LTD
  • EP4027074B1 patent drawingFigure 1
  • EP4027074B1 patent drawingFigure 2~3
  • EP4027074B1 patent drawingFigure 4

AI summary

A compressor unit (20) includes a first case (20a), a first compressor (21), a cascade heat exchanger (24), a second compressor (25), a first connecting port (23), and a second connecting port (28). The first compressor (21), the cascade heat exchanger (24), and a heat source heat exchanger (11) accommodated in a second case (10a) constitute a first refrigerant cycle (C1). The second compressor (25), the cascade heat exchanger (24), and a utilization heat exchanger (52) accommodated in a third case (50a) constitute a second refrigerant cycle (C2). The first connecting port (23) is connected to the heat source heat exchanger (11) via a first connection piping (30). The second connecting port (29) is connected to the utilization heat exchanger (52) via a second connection piping (40).