Liquid Refrigerant Line Sensing for Charge Level Detection

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Solution Overview

Problem

Monitoring the refrigerant charge level in air conditioner or heat pump systems is tedious and time-consuming, requiring expertise to analyze temperature data and relate it to system performance, which hinders efficiency and increases operational costs.

Innovation Solution

A system comprising sensors for measuring temperature and pressure in the liquid refrigerant line, a controller to determine target pressure values based on temperature, and a display to indicate if the refrigerant charge is at, above, or below an acceptable level, facilitating easy monitoring of refrigerant charge levels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If temperature measuring equipment is used to monitor refrigerant charge level, then measurement precision is improved, but device complexity and ease of operation deteriorate due to tedious analysis requirements

Engineering Contradiction:

Improverefrigerant charge level detection accuracyVSAvoidmonitoring operation simplicity

Core Design Contradiction:

Measurement precisionVSEase of operation

Solution Approach 1:

The patent introduces an intermediary device (refrigerant charge level monitor) that automatically processes temperature measurements and compares them against stored reference data. This intermediary handles the complex analysis work, presenting simplified charge level status to users without requiring manual temperature data interpretation.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system performs self-service by automatically comparing measured temperatures with reference temperature data stored in memory, and autonomously determining refrigerant charge status. The device serves itself by having built-in reference data and automated comparison logic, eliminating the need for user expertise in temperature analysis.

Inventive Principle:

Principle #25Self-service

2Measurement precision

If expert analysis of temperature data is required, then measurement precision is improved, but loss of time increases due to tedious monitoring tasks

Engineering Contradiction:

Improverefrigerant charge level detection accuracyVSAvoidmonitoring time consumption

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent replaces manual expert analysis (mechanical human process) with automated electronic processing. The microprocessor automatically compares temperature measurements against reference data, substituting the need for human expertise and dramatically reducing the time required for charge level determination.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system performs self-service by having built-in reference data and automated comparison logic, eliminating the need for user expertise in temperature analysis.

Inventive Principle:

Principle #25Self-service

3Measurement precision

If manual temperature data analysis is used, then measurement precision is maintained, but productivity deteriorates due to time-consuming monitoring

Engineering Contradiction:

Improverefrigerant charge level detection accuracyVSAvoidmonitoring efficiency

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The patent implements continuous feedback by automatically monitoring temperature, comparing it with reference data, and providing real-time charge level status. This continuous automated feedback loop maintains measurement precision while dramatically improving monitoring efficiency compared to periodic manual analysis.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent replaces manual expert analysis (mechanical human process) with automated electronic processing.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 solution simplifies the monitoring process, enabling users to quickly determine if the refrigerant charge is within an acceptable range, thereby improving system efficiency and reducing energy costs by providing real-time feedback on refrigerant levels.

Implementation Method 1

a first sensor that provides an output indicative of a sensed temperature of a liquid refrigerant line

Methodology Applied

Scientific EffectTemperature sensing:

Implementation Method 2

a second sensor that provides an output indicative of a sensed pressure in the liquid refrigerant line

Methodology Applied

Scientific EffectPressure sensing:

Data Source

PatentUS8466798B2Refrigerant charge level detection

Publication Date: 2013.06.18 COPELAND COMFORT CONTROL LP

AI summary

A system includes a first sensor that provides an output indicative of a sensed temperature of a liquid refrigerant line that is within or extending from an outlet of a condenser coil of an air conditioner or heat pump unit. The system includes a second sensor that provides an output indicative of a sensed pressure in the liquid refrigerant line. A controller is configured to determine at least one target pressure value from the output indicative of the sensed temperature of the liquid refrigerant line. The controller is configured to determine if the level of refrigerant charge is at, above or below an acceptable level based on a comparison of the output indicative of sensed pressure to the at least one target pressure value. The system includes a display that displays an indication of whether the level of refrigerant charge is at, above or below an acceptable level.