Refrigerant Blend Composition for Low-GWP R404A Replacement
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Solution Overview
Problem
The refrigeration industry faces challenges in finding replacements for high global warming potential (GWP) refrigerants like R404A, R407A, and R507A that also meet low toxicity, non-flammability, and existing system performance parameters, due to upcoming environmental regulations.
Innovation Solution
Compositions comprising 4-16 weight percent of HFO-1234yf, 34-38 weight percent of HFC-32, and 48-60 weight percent of trans-HFO-1234ze, optionally with non-refrigerant components, are used as replacements in refrigeration systems, providing low GWP, Class A toxicity, and reduced flammability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If HFC refrigerants (e.g., R-134a) are used to replace CFCs and HCFCs, then ozone depletion potential is eliminated, but global warming potential increases and may lead to future regulatory phase-out
Solution Approach 1:
The patent changes the chemical composition parameters by using HFO-1234yf and trans-HFO-1234ze (olefin-based compounds) instead of traditional HFC refrigerants. This parameter change results in dramatically reduced GWP (less than 150) while maintaining zero ODP, thereby resolving the contradiction between eliminating ozone depletion and reducing global warming potential.
Solution Approach 2:
The patent employs a composite refrigerant formulation consisting of multiple components: HFO-1234yf (4-16 wt%), trans-HFO-1234ze (82-92 wt%), and HFC-32 (34-38 wt%). This composite approach allows the mixture to achieve low GWP, non-flammability, and acceptable toxicity levels that individual components alone cannot provide, thus resolving the environmental harm contradiction.
2Object-generated harmful factors
If natural refrigerants (e.g., CO2, hydrocarbons) are used to replace HFCs, then global warming potential is reduced, but flammability and toxicity increase
Solution Approach 1:
The patent uses HFO-1234yf and trans-HFO-1234ze as intermediary substances that bridge the gap between natural refrigerants and synthetic HFCs. These olefin-based compounds provide low GWP like natural refrigerants but with significantly reduced flammability and improved toxicity profiles, thereby resolving the contradiction between reducing GWP and maintaining safety.
Solution Approach 2:
By changing from hydrocarbon-based natural refrigerants to HFO-based compounds, the patent modifies the chemical structure parameters (introducing fluorine atoms and double bonds) which reduces flammability while maintaining low GWP. The specific compositional ratios (4-16 wt% HFO-1234yf, 82-92 wt% trans-HFO-1234ze, 34-38 wt% HFC-32) are optimized to achieve non-flammability and Class A toxicity rating.
3Object-generated harmful factors
If HFC-32 is used as a replacement refrigerant, then GWP is reduced compared to R-134a, but flammability increases
Solution Approach 1:
The patent merges HFC-32 (which has low GWP but is flammable) with HFO-1234yf and trans-HFO-1234ze (which have very low GWP and low flammability). By combining these components in specific ratios (34-38 wt% HFC-32 with 4-16 wt% HFO-1234yf and 82-92 wt% trans-HFO-1234ze), the mixture achieves non-flammability while maintaining low GWP, thereby resolving the contradiction between reducing GWP and reducing flammability.
Solution Approach 2:
The patent creates a composite refrigerant mixture where HFC-32 is combined with HFO-1234yf and trans-HFO-1234ze. This composite formulation allows the benefits of low-GWP components to be realized while the flammability of HFC-32 is suppressed by the presence of the other components, achieving both low GWP and non-flammability simultaneously.
Data Source
Figure 1
AI summary
In accordance with the present invention compositions are disclosed. The compositions consist of: (A) a refrigerant component consisting essentially of (1) at least one refrigerant having an OEL less than 400; and (2) a combination of refrigerants, each having an OEL greater than 400, consisting essentially of (i) at least one refrigerant selected from the group consisting of HFC-32 and HFC-152a; and (ii) trans-HFO-1234ze; and optionally (B) a non-refrigerant component; wherein component (A)(2) of the refrigerant component is present in an amount sufficient to provide an overall OEL for the refrigerant component of at least 400. The refrigerant mixtures of the refrigerant component are useful as components in compositions also containing non-refrigerant components (e.g. lubricants), in processes to produce refrigeration, in methods for replacing refrigerant R404A, R407A, R407F or R-507A, and in refrigeration apparatus.