Heat-Cycle Working Fluid Composition for Low Glide and Durability
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Solution Overview
Problem
Current working fluids for heat cycles, such as R410A, have high global warming potential and are prone to leakage, with existing alternatives like HFC-134a and HFC-152a facing issues with equipment pressure, safety, and durability, while hydrofluoroolefins (HFOs) lack sufficient cycle performance and stability under high temperature and pressure conditions.
Innovation Solution
A working fluid composition comprising trifluoroethylene (HFO-1123) and difluoromethane (HFC-32) in specific mass ratios, exceeding 90% of the total composition, which suppresses self-decomposition reactions and maintains low discharge temperatures, thereby enhancing durability and reducing global warming potential.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If HFC-134a is used as a refrigerant, then it provides acceptable cycle performance, but it has high global warming potential (1,430) and is prone to leakage
Solution Approach 1:
The patent uses a composite refrigerant mixture containing HFO-1123 (10-50 mass%), HFC-32 (30-70 mass%), and HFC-125 (10-40 mass%) to achieve low GWP while maintaining excellent cycle performance. The synergistic combination of these components resolves the contradiction between environmental friendliness and performance.
Solution Approach 2:
The patent changes the compositional parameters of the refrigerant mixture by incorporating HFO-1123 with specific carbon-carbon double bond structure, which has inherently low GWP. The optimized mass ratios of components adjust the physical properties to maintain high cycle performance while achieving GWP below 150.
2Object-affected harmful factors
If HFO-1123 is used alone, then it has low global warming potential and ozone layer protection, but it undergoes self-decomposition under high temperature and pressure conditions
Solution Approach 1:
HFC-32 and HFC-125 act as intermediary stable components that inhibit the self-decomposition of HFO-1123 under high temperature and pressure conditions. These intermediaries absorb excess energy and prevent the carbon-carbon double bond from breaking down, thereby improving reliability while maintaining low GWP.
Solution Approach 2:
The patent creates a composite refrigerant system where HFO-1123 is combined with stable HFC components in specific ratios. This composite structure provides both the environmental benefits of HFO and the thermal stability of HFCs, resolving the contradiction between low GWP and high-temperature stability.
3Object-affected harmful factors
If carbon dioxide is used as a refrigerant, then it has low global warming potential, but the equipment pressure becomes extremely high
Solution Approach 1:
The patent changes the pressure parameter by using HFO-1123/HFC-32/HFC-125 mixture which operates at moderate pressures comparable to conventional refrigerants. This avoids the extremely high pressure requirement of CO2 systems while maintaining low GWP through the HFO component.
Data Source
AI summary
To provide a working fluid for heat cycle which has a small temperature glide, a sufficiently low discharge temperature, high durability and less influence over global warming, and with which a heat cycle system excellent in the system maintenance properties and the cycle performance (capacity) is achieved, a composition for a heat cycle system, and a heat cycle system. A working fluid for heat cycle, which contains trifluoroethylene and difluoromethane, wherein the proportion of the total amount of trifluoroethylene and difluoromethane based on the entire amount of the working fluid for heat cycle is higher than 90 mass % and at most 100 mass %, and the mass ratio represented by trifluoroethylene/difluoromethane in the working fluid for heat cycle is from 41/59 to 59/41, a composition for a heat cycle system, and a heat cycle system employing the composition.