Compressor Oil De-Stagnation for Accurate Refrigerant Charge Judgment
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Solution Overview
Problem
Conventional refrigerant leak detection methods in air conditioners face increased error due to refrigerant solubility in machine oil, particularly at low temperatures, leading to inaccurate refrigerant quantity judgments.
Innovation Solution
The air conditioner incorporates a refrigerant stagnation judging mechanism and operation controller to eliminate refrigerant stagnation within the compression mechanism, allowing for precise refrigerant quantity judgments by determining stagnation based on temperature, weather information, or set intervals, and performing de-stagnation operations to reduce prediction errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If refrigerant leak detection is performed using fixed temperature set values, then the detection operation is simple, but prediction error of refrigerant quantity increases when outside temperature is low
Solution Approach 1:
The patent changes the temperature parameter dynamically based on outside temperature conditions. Instead of using fixed temperature set values, the system adjusts the temperature parameter according to the actual operating conditions, thereby maintaining measurement precision across different environmental temperatures while keeping the detection operation straightforward.
2Loss of time
If refrigerant leak detection is performed immediately after compressor startup, then the detection can be performed quickly, but internal oil temperature is low causing increased prediction error
Solution Approach 1:
The patent applies preliminary action by pre-warming the compressor and measuring the internal oil temperature before performing refrigerant leak detection. This ensures that the refrigerant and oil are at appropriate temperatures for accurate measurement, eliminating prediction errors caused by low temperatures while minimizing the overall detection time through efficient pre-conditioning.
3Use of energy by moving object
If only a portion of compressors are driven during detection, then energy consumption is reduced, but refrigerant stagnation in oil increases prediction error
Solution Approach 1:
The patent applies partial action by driving only the necessary portion of compressors during detection based on system requirements. It optimizes the balance between energy consumption and measurement accuracy by determining the minimum compressor operation needed to achieve sufficient oil temperature and refrigerant circulation for accurate detection, avoiding unnecessary energy waste while ensuring adequate mixing.
4Productivity
If refrigerant stagnation is present in compression mechanism, then the system operates normally under usual conditions, but refrigerant quantity prediction error increases during detection
Solution Approach 1:
The patent applies periodic action by implementing regular refrigerant circulation operations that periodically mix the refrigerant with the oil in the compression mechanism. This periodic mixing prevents permanent stagnation and ensures that during detection operations, the refrigerant distribution is representative of actual system conditions, thereby maintaining both operational efficiency and detection accuracy.
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 refrigerant quantity judgments by eliminating stagnation, reducing prediction errors, and extending system service life by distributing load across multiple compressors and preventing complete system stoppages during low-load operations.
Implementation Method 1
a refrigerant stagnation judging means for judging whether refrigerant is stagnant inside a compression mechanism
Implementation Method 2
an operation controller which performs a refrigerant de-stagnation operation for eliminating stagnation of the refrigerant when the refrigerant stagnation judging means has judged in advance that the refrigerant is stagnant inside the compression mechanism
Implementation Method 3
The heat source unit has a compression mechanism and a heat source side heat exchanger. A utilization unit has a utilization side heat source exchanger
Data Source
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AI summary
An object of the present invention is to eliminate stagnation of refrigerant in refrigerating machine oil in a compression mechanism, and to use the difference in the solubility of the refrigerant in the oil to minimize error in predicting the quantity of refrigerant. An air conditioner (1) is provided with a refrigerant circuit (7), refrigerant stagnation judgment means (8a to 8c), and an operation controller (6a to 6c). The refrigerant circuit is a circuit that includes a heat source unit (2a to 2c), a refrigerant communication pipe (4, 5), an expansion mechanism (31a, 31 b, ... ), and a utilization unit (29a to 29c, 3a, 3b, ... ). A heat source unit and a utilization unit are connected to the refrigerant fluid communication pipes. The heat source unit has a compression mechanism (21a to 21c) and a heat source side heat exchanger (24a to 24c). The refrigerant stagnation judging means can judge whether the refrigerant has stagnated inside the compression mechanism. The operation controller performs a refrigerant de-stagnation operation for eliminating stagnation of the refrigerant in the case that the refrigerant stagnation judging means has judged in advance that the refrigerant inside the compression mechanism has stagnated when a refrigerant quantity judging operation is carried out for judging the refrigerant quantity inside the refrigerant circuit.