Refrigeration cycle device

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Accurately detecting abnormalities in electronic expansion valves and solenoid valves within a multifunctional refrigeration cycle apparatus capable of cooling and heating mixed operations is challenging due to the complexity of the system.

Innovation Solution

The refrigeration cycle apparatus employs a configuration where the compressor operates with the indoor heat exchanger as a condenser, with specific valve positions to utilize temperature sensors for abnormality detection by comparing measured temperatures against predetermined thresholds, allowing for precise identification of valve issues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple valves (electronic expansion valve and two solenoid valves) are provided for each indoor heat exchanger to enable multifunctional operation, then the adaptability and versatility of the refrigeration cycle apparatus is improved, but the device complexity increases and abnormality detection becomes more difficult

Engineering Contradiction:
Improvemultifunctional operation capabilityVSAvoidvalve configuration complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the abnormality detection process into distinct operational modes (heating mode and cooling mode) with specific detection sequences. In heating mode, the electronic expansion valve is detected first, then the solenoid valves; in cooling mode, the detection sequence is reversed. This segmented approach simplifies the complex detection task by breaking it down into manageable stages based on operational context.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary actions by setting specific valve states before detection. Before detecting the electronic expansion valve, the solenoid valves are set to predetermined positions. Before detecting solenoid valves, the electronic expansion valve is positioned appropriately. This preliminary configuration ensures that temperature differences observed during detection are solely due to the valve being tested, not other valves in the system.

Inventive Principle:
Principle #10Preliminary action

2Adaptability or versatility

If multiple valves are provided for each indoor heat exchanger, then the adaptability is improved, but the measurement precision of abnormality detection deteriorates due to interference from multiple components

Engineering Contradiction:
Improvecooling and heating mixed operationVSAvoidabnormality detection accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent extracts the detection of each valve's abnormality into separate, independent detection processes. By isolating the detection of the electronic expansion valve from the solenoid valves (and vice versa) through specific operational modes and sequences, the system eliminates interference between components. This allows each valve's temperature characteristics to be measured independently, improving detection precision.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent employs dynamic detection strategies where the detection sequence and valve states change based on the operational mode. In heating mode, the system detects the electronic expansion valve first with solenoid valves in specific positions, then detects solenoid valves with the electronic expansion valve positioned differently. This dynamic adaptation ensures optimal detection conditions for each valve type.

Inventive Principle:
Principle #15Dynamics

3Ease of operation

If conventional abnormality detection methods are used in complex valve configurations, then the ease of operation is maintained, but the reliability of abnormality detection deteriorates

Engineering Contradiction:
Improvedetection operation simplicityVSAvoidabnormality detection reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent implements feedback mechanisms where temperature sensor readings are continuously monitored and compared against expected values. When temperature differences exceed predetermined thresholds, the system identifies abnormalities and can trigger alerts or corrective actions. This feedback loop ensures reliable detection while maintaining automated operation, reducing the need for manual intervention.

Inventive Principle:
Principle #23Feedback

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 approach enables more accurate and timely detection of abnormalities in the valves, facilitating earlier intervention and reducing the duration of poor system performance.

Implementation Method 1

a third temperature sensor configured to measure a temperature of refrigerant at a gas portion of the indoor heat exchanger

Methodology Applied
Scientific EffectTemperature measurement:

Implementation Method 2

a second temperature sensor configured to measure a temperature of refrigerant at a liquid portion of the indoor heat exchanger

Methodology Applied
Scientific EffectTemperature measurement:

Implementation Method 3

a first temperature sensor configured to measure a temperature in the room

Methodology Applied
Scientific EffectTemperature measurement:

Implementation Method 4

a saturation temperature obtained by converting a condensing pressure of the refrigerant

Methodology Applied
Scientific EffectPressure-temperature conversion:

Data Source

PatentEP3933307B1Refrigeration cycle device
Publication Date: 2023.08.02 MITSUBISHI ELECTRIC CORP
  • EP3933307B1 patent drawingFigure 1
  • EP3933307B1 patent drawingFigure 2~3
  • EP3933307B1 patent drawingFigure 4~5

AI summary

A refrigeration cycle apparatus includes a refrigeration cycle circuit, a first junction portion, a second junction portion, a bypass pipe connecting the first junction portion and the second junction portion, a first valve provided between the second junction portion and a refrigerant flow switching device, a second valve provided to the bypass pipe, a first temperature sensor configured to measure a temperature in a room, a second temperature sensor configured to measure a temperature of refrigerant at a liquid portion of an indoor heat exchanger, and a third temperature sensor configured to measure a temperature of refrigerant at a gas portion of the indoor heat exchanger. In an operation status in which a compressor operates, the indoor heat exchanger operates as a condenser, the first valve is closed, and the second valve is opened, when a temperature obtained by subtracting a temperature measured by the third temperature sensor from a saturation temperature obtained by converting a condensing pressure of the refrigerant is larger than a first threshold temperature, or when a temperature obtained by subtracting a temperature measured by the first temperature sensor from a temperature measured by the second temperature sensor is smaller than a second threshold temperature, the refrigeration cycle apparatus is configured to detect an abnormality at at least one of an expansion valve and the second valve.