Mixed Refrigerant Filling to Control Transfer Composition Drift
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Non-azeotropic refrigerant mixtures, such as those comprising difluoromethane and 2,3,3-tetrafluoropropene, experience significant composition changes during transfer due to differences in boiling points, leading to performance degradation and safety concerns related to flammability, making it challenging to maintain the desired composition within acceptable limits.
Innovation Solution
A method for filling refrigerant mixtures involves adjusting the initial composition of difluoromethane in the liquid phase before transfer to specific ranges, using equations to calculate optimal proportions that minimize composition changes within ±a wt% of the target composition, ensuring consistent refrigerant performance and safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If non-azeotropic refrigerant mixtures are used to improve performance and achieve non-flammability, then refrigerant safety and performance are improved, but composition changes occur during transfer due to boiling point differences, leading to performance degradation and flammability concerns
Solution Approach 1:
The patent applies preliminary action by calculating and setting the initial composition of the refrigerant mixture before transfer to account for expected evaporation losses. The low-boiling-point component is intentionally added in excess beforehand, so that after transfer and phase changes, the final composition remains within the non-flammable range. This preemptive adjustment prevents composition instability during the transfer process.
Solution Approach 2:
The patent changes the concentration parameter of the low-boiling-point component in the refrigerant mixture. By adjusting the initial concentration of components with different boiling points, the patent compensates for selective evaporation during transfer. This parameter adjustment ensures that despite composition changes, the final mixture maintains safe flammability characteristics and desired performance.
2Productivity
If components with large boiling point difference are used to improve refrigerant performance, then refrigerant efficiency is improved, but composition changes of a few percent occur during transfer, causing significant performance change and safety impact
Solution Approach 1:
The patent performs preliminary calculation of the initial composition required to achieve the target composition after transfer. By anticipating the selective evaporation of low-boiling-point components during transfer, the system pre-adjusts the mixture composition accordingly. This preliminary action ensures that even with a few percent composition changes, the final refrigerant efficiency and safety parameters remain within acceptable tolerances.
Solution Approach 2:
The patent implements a feedback mechanism where the initial composition is calculated based on expected transfer losses and final composition requirements. The system uses mathematical models to predict composition changes and adjusts the initial mixture accordingly, creating a closed-loop approach that compensates for transfer-induced composition variations and maintains manufacturing precision.
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
The method effectively controls composition changes during transfer, maintaining refrigerant performance and safety by adjusting the initial composition of difluoromethane within predetermined ranges, thereby ensuring the refrigerant mixture meets the target composition criteria.
Implementation Method 1
low-boiling-point components are more likely to be evaporated, and high-boiling-point components are more likely to be condensed
Implementation Method 2
low-boiling-point components are more likely to be evaporated, and high-boiling-point components are more likely to be condensed
Implementation Method 3
undergo composition changes during phase changes, such as evaporation and condensation
Data Source
AI summary
A principal object of the present invention is to provide a method for filling a refrigerant mixture. According to this method, when a non-azeotropic refrigerant mixture comprising HFC-32 and HFO-1234yf is transferred, changes in the composition that occur during the transfer can be made to fall within an acceptable range in terms of refrigerant properties.