Compressor Oil Refrigerant Estimation for Accurate AC Charge Judgment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for judging the adequacy of refrigerant quantity in air conditioner circuits are inefficient due to high calculation loads and inaccuracies caused by temperature distributions in refrigerating machine oil, making it difficult to determine the correct refrigerant quantity dissolved in the oil reservoir.
Innovation Solution
An air conditioner system that calculates refrigerant quantity by considering operation state quantities such as ambient temperature, refrigerant temperature, and pressure, using these to accurately determine the dissolved refrigerant quantity in the compressor oil, thereby improving the judgment accuracy of refrigerant adequacy without the need for additional temperature sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If simulation of refrigeration cycle characteristics is performed to judge refrigerant quantity, then judgment accuracy is improved, but calculation time becomes excessively long and calculation might be impossible with low-cost devices
Solution Approach 1:
The patent segments the complex refrigeration cycle simulation into simplified calculation sections, dividing the refrigerant circuit into multiple portions and using relational expressions for each section. This segmentation reduces the overall calculation load while maintaining sufficient accuracy for refrigerant quantity judgment.
Solution Approach 2:
The patent changes the calculation parameters from full cycle simulation to key state quantities (temperature, pressure, flow rates) at specific locations. By using operational state quantities that can be measured or easily calculated, the system achieves practical refrigerant quantity judgment without excessive computation.
2Measurement precision
If temperature of refrigerating machine oil in oil reservoir is detected to calculate dissolved refrigerant quantity, then calculation accuracy is improved, but additional temperature sensors and device complexity are required
Solution Approach 1:
The patent uses the compressor's existing motor temperature detection function to obtain oil temperature data. The motor temperature sensor serves dual purposes: monitoring motor health and providing temperature data for dissolved refrigerant calculation. This self-service approach eliminates additional sensors while maintaining calculation accuracy.
Solution Approach 2:
The temperature sensor originally designed for motor protection is made multi-functional by also using it for dissolved refrigerant quantity calculation. This universal utilization of existing sensors reduces device complexity while achieving the desired measurement precision.
3Productivity
If simple calculation methods are used for refrigerant quantity, then calculation speed is improved, but judgment accuracy deteriorates due to inability to account for temperature distributions in oil
Solution Approach 1:
The patent applies local quality by considering temperature distributions within the oil reservoir through relational expressions that account for local temperature variations. Instead of assuming uniform temperature, the calculation method incorporates local temperature differences caused by refrigerant contact and wall surface temperatures, improving accuracy without excessive computation.
Solution Approach 2:
The patent replaces complex physical measurement systems with mathematical relational expressions. By using calculated temperature distributions based on known parameters (refrigerant temperature, wall surface temperature) rather than direct physical measurement of oil temperature at multiple points, the system achieves good accuracy with simple computation.
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 allows for high-accuracy judgment of refrigerant adequacy by accounting for temperature distributions in the refrigerating machine oil, reducing calculation errors and improving the efficiency of refrigerant quantity determination.
Implementation Method 1
the quantity of refrigerant dissolved in the refrigerating machine oil in the compressor
Data Source
AI summary
An air conditioner includes a refrigerant circuit, a refrigerant quantity calculating section, and a refrigerant quantity judging section. The refrigerant circuit includes a compressor, an outdoor heat exchanger, an indoor expansion valve, and an indoor heat exchanger interconnected together. The refrigerant quantity calculating section calculates the refrigerant quantity in the refrigerant circuit taking into account a dissolved refrigerant quantity that is the quantity of refrigerant dissolved in the refrigerating machine oil in the compressor, based on an operation state quantity of constituent equipment or refrigerant flowing in the refrigerant circuit. The refrigerant quantity judging section judges the adequacy of the refrigerant quantity in the refrigerant circuit based on the refrigerant quantity calculated by the refrigerant quantity calculating section. In addition, the refrigerant quantity calculating section calculates the dissolved refrigerant quantity based on operation state quantities that include at least the ambient temperature outside the compressor.