Mixed Refrigerant Filling for Composition Drift Control
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Solution Overview
Problem
Non-azeotropic refrigerant mixtures, such as those comprising HFO-1234ze(E) and HFC-32, 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 refrigerant composition within acceptable tolerances.
Innovation Solution
A method for filling refrigerant mixtures involves adjusting the initial composition of HFC-32 in the liquid phase of the refrigerant mixture in the feeding container to specific ranges before transfer, using equations to calculate the necessary adjustments (e.g., Equations (1) to (18)) to ensure the composition remains within target upper-limit and lower-limit compositions during transfer, thereby minimizing changes and maintaining performance and safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If non-azeotropic refrigerant mixtures comprising HFO-1234ze(E) and HFC-32 are used, then refrigerant performance and environmental friendliness are improved, but composition changes occur during transfer leading to performance degradation and safety concerns
Solution Approach 1:
The patent applies preliminary action by calculating and adjusting the initial composition of HFC-32 in the liquid phase before transfer begins. The initial proportion is set to a specific range (x+y1 to x wt%) based on predicted evaporation losses, ensuring that even after composition changes during transfer, the final composition remains within acceptable tolerances. This proactive adjustment prevents performance degradation before it occurs.
Solution Approach 2:
The patent utilizes parameter changes by modifying the initial concentration of HFC-32 based on multiple factors including filling amount, transfer temperature, and target composition. The initial proportion is calculated using equations that account for these parameters, allowing the system to adapt to different operating conditions while maintaining composition stability throughout the transfer process.
2Stability of the object's composition
If the initial composition of HFC-32 is adjusted to compensate for evaporation, then composition stability is improved, but calculation complexity and filling process complexity increase
Solution Approach 1:
The patent replaces complex real-time monitoring and adjustment mechanisms with pre-calculated initial composition settings. Instead of using sophisticated control systems to maintain composition during transfer, the method uses mathematical equations to determine the optimal initial HFC-32 proportion before transfer begins, simplifying the filling process while maintaining composition stability.
3Object-affected harmful factors
If HFO-1234ze(E) is used as an alternative to conventional refrigerants, then environmental friendliness and low toxicity are improved, but vapor pressure is insufficient leading to performance degradation
Solution Approach 1:
The patent applies composite materials by creating a refrigerant mixture that combines HFO-1234ze(E) with HFC-32 in specific proportions. This composite refrigerant mixture leverages the environmental benefits of HFO-1234ze(E) (low GWP, low toxicity) while compensating for its insufficient vapor pressure through the addition of HFC-32, achieving both environmental friendliness and adequate refrigerant capability.
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 method effectively controls composition changes within acceptable ranges, ensuring consistent refrigerant performance and safety by adjusting the initial composition of HFC-32 in the refrigerant mixture before transfer, thus addressing the issues of performance degradation and flammability.
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
An object of the present invention is to provide a method for filling a refrigerant mixture. This method enables composition changes of a non-azeotropic refrigerant mixture comprising HFO-1234ze(E) and HFC-32 during the transfer to fall within an acceptable range of refrigerant performance. The method for filling a refrigerant mixture comprising HFC-32 and HFO-1234ze(E), the HFC-32 being present in a liquid phase of the refrigerant mixture in an amount of 10 to 90 wt % based on 100 wt % of the total of the HFC-32 and HFO-1234ze(E), comprises, in transferring the refrigerant mixture in a liquid state to a target container or equipment from a feeding container, adjusting the proportion (initial composition) of the HFC-32 in the liquid phase of the refrigerant mixture in the feeding container immediately before the transfer to x+y1 (minimum value) to x wt % (target upper-limit composition), so that the proportion of the HFC-32 in the liquid phase of the refrigerant mixture in the feeding container falls within a range from the target upper-limit composition (x) of the HFC-32 to the target upper-limit composition (x)—4.0 wt % (target lower-limit composition) during initiation and completion of the transfer.