Refrigeration cycle apparatus determining refrigerant condenser amount

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional refrigeration cycle apparatuses face challenges in accurately calculating the refrigerant amount due to errors caused by installation environment factors and the need for coefficient regulation, leading to insufficient accuracy in determining refrigerant excess or shortage.

Innovation Solution

A refrigeration cycle apparatus with multiple temperature sensors in line along the refrigerant flow direction in the condenser, a memory unit for positional information, and a refrigerant amount calculation unit that calculates the refrigerant amount based on detected temperatures and saturated liquid temperatures, eliminating the need for error regulation by coefficients.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If refrigerant amount is calculated using heat exchange amount and volumetric proportion estimation, then refrigerant amount can be determined, but calculation accuracy is insufficient due to installation environment errors and coefficient regulation requirements

Engineering Contradiction:

Improverefrigerant amount calculation accuracyVSAvoidcoefficient regulation and error compensation requirements

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The condenser is divided into multiple sections with temperature sensors placed at different positions (inlet, outlet, and intermediate positions). This segmentation allows direct measurement of temperature distribution throughout the condenser, eliminating the need for complex heat exchange calculations and coefficient regulations. Each segment's temperature data is used to calculate the refrigerant amount in that specific section, improving overall accuracy.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent replaces the conventional indirect calculation method (based on heat exchange amounts and volumetric proportions) with a direct measurement approach using temperature sensors. This substitution of measurement methodology eliminates the need for coefficient regulation and error compensation, directly improving calculation accuracy while reducing system complexity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If multiple temperature sensors are disposed in line in the direction of refrigerant flow, then calculation accuracy is improved, but device complexity increases

Engineering Contradiction:

Improverefrigerant amount calculation accuracyVSAvoidnumber of temperature sensors and installation complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The temperature sensors serve multiple functions: they detect refrigerant temperature at specific positions, determine the state of refrigerant (subcooled, saturated, or superheated), and provide data for calculating volumetric proportions. This multi-functionality justifies the addition of multiple sensors while maximizing their utility in improving calculation accuracy.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

Temperature sensors are strategically placed at specific locations within the condenser (inlet, outlet, and intermediate positions) where they can most effectively capture the temperature distribution characteristics. This localized placement ensures that each sensor provides meaningful data for calculating the refrigerant amount in its specific region, improving overall measurement precision without unnecessary sensors.

Inventive Principle:

Principle #3Local quality

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 improves the accuracy of refrigerant amount calculation by directly obtaining volumetric proportions from temperature sensor data, reducing errors and enhancing the determination of refrigerant excess or shortage without relying on coefficients.

Implementation Method 1

multiple temperature sensors that are disposed in line in a direction in which refrigerant flows in the condenser and detect refrigerant temperature of the condense

Methodology Applied

Scientific EffectThermal energy detection:

Implementation Method 2

a refrigerant amount calculation unit that calculates a refrigerant amount of the condenser based on the positional information of the multiple temperature sensors, detected temperatures of the multiple temperature sensors and a saturated liquid temperature of the refrigerant

Methodology Applied

Scientific EffectSaturated liquid temperature reference:

Data Source

PatentUS10684051B2Refrigeration cycle apparatus determining refrigerant condenser amount

Publication Date: 2020.06.16 MITSUBISHI ELECTRIC CORP

AI summary

A refrigeration cycle apparatus includes a refrigerant circuit that includes a condenser, multiple temperature sensors that are disposed in line in a direction in which refrigerant flows in the condenser and detect refrigerant temperature of the condenser, a memory unit that stores positional information of the multiple temperature sensors, and a refrigerant amount calculation unit that calculates a refrigerant amount of the condenser based on the positional information of the multiple temperature sensors, detected temperatures of the multiple temperature sensors and a saturated liquid temperature of the refrigerant.