Heat transfer fluids comprising difluoromethane, pentafluoroethane, tetrafluoropropene and optionally propane
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Solution Overview
Problem
Current heat transfer fluids with low global warming potential (GWP) that replace R404a are either flammable, inefficient, have significant temperature glide, or require expensive compressor modifications, especially when used in equipment with piston technology.
Innovation Solution
A composition comprising 11-13% difluoromethane, 58-62% pentafluoroethane, 18-29% 2,3,3,3-tetrafluoropropene, and optionally 0-7% propane, which serves as a non-flammable heat transfer fluid in vapor compression systems, maintaining performance without major equipment modifications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional refrigerants (R404a) are used, then high performance and reliability are achieved, but high GWP (global warming potential) and environmental damage occur
Solution Approach 1:
The patent changes the chemical composition parameters by using HFC-125 and HFO-1234yf instead of conventional refrigerants, achieving low GWP (less than 150) while maintaining acceptable performance in heat transfer systems
Solution Approach 2:
The patent creates a composite refrigerant mixture comprising HFC-125 and HFO-1234yf in specific proportions (60-80% HFC-125 and 20-40% HFO-1234yf), combining the low GWP properties of HFO with the stable thermodynamic properties of HFC to achieve both environmental compliance and system reliability
2Object-affected harmful factors
If alternative low GWP compositions are used to replace R404a, then environmental impact is reduced, but flammability, low performance, temperature glide, and equipment incompatibility occur
Solution Approach 1:
The patent optimizes the compositional parameters within specific ranges (60-80% HFC-125, 20-40% HFO-1234yf) to balance environmental performance (low GWP) with operational reliability (non-flammability, acceptable temperature glide, and compatibility with existing equipment including piston compressors)
3Adaptability or versatility
If liquid injection technology is used in compressors to enable alternative refrigerants, then compatibility with low GWP fluids is achieved, but device complexity and cost increase
Solution Approach 1:
The patent modifies the refrigerant's physical and chemical parameters (using HFC-125/HFO-1234yf mixture with specific composition ranges) to ensure compatibility with conventional piston compressors without requiring liquid injection technology or other complex modifications, thereby maintaining simplicity and cost-effectiveness
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 solution provides heat transfer fluids with low GWP, improved energy efficiency, and reduced temperature glide, suitable for use in existing equipment, including those with piston technology, while maintaining performance comparable to R404a.
Implementation Method 1
vaporization of the fluid at low pressure (during which the fluid absorbs heat)
Implementation Method 2
condensation of the vaporized fluid into a liquid at high pressure (during which the fluid releases heat)
Implementation Method 3
compression of the vaporized fluid to a high pressure
Implementation Method 4
expansion of the fluid to complete the cycle
Data Source
AI summary
The invention relates to a composition comprising: between 11 and 13 wt.% of difluoromethane; between 58 and 62 wt.% of pentafluoroethane; between 18 and 29 wt.% of tetrafluoropropene; and between 0 and 7 wt.% of propane. The tetrafluoropropene can be 1,3,3,3-tetrafluoropropene or 2,3,3,3-tetrafluoropropene. Said composition can be used as a heat transfer fluid in a vapour compression circuit.