Working medium and heat-cycle system
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Solution Overview
Problem
Current working mediums for heat cycles, such as hydrofluorocarbons (HFCs), pose risks to the ozone layer and contribute to global warming, while alternatives like hydrofluoroolefins (HFOs) have insufficient cycle performance and combustibility issues.
Innovation Solution
A working medium comprising 1,1,2-trifluoroethylene (HFO-1123) combined with a hydrocarbon and optionally a HFC or hydrochlorofluoroolefin, which enhances cycle performance, suppresses combustibility, and reduces environmental impact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If HFCs are used as working medium, then ozone layer depletion is reduced, but global warming potential increases
Solution Approach 1:
The patent changes the chemical composition parameters by introducing HFO-1123 with specific molecular structure (carbon-carbon double bond) that fundamentally alters both ozone depletion potential and global warming potential, achieving reduction in both harmful effects simultaneously
Solution Approach 2:
The patent creates a composite working medium by blending HFO-1123 with hydrocarbons (propane, isobutane, or a mixture), where each component contributes different properties that together achieve low GWP while maintaining acceptable safety and performance characteristics
2Object-generated harmful factors
If HFOs are used as working medium, then global warming potential is reduced, but cycle performance becomes insufficient
Solution Approach 1:
The patent optimizes the compositional parameters by precisely controlling the ratios of HFO-1123 (5-95 mass%) and hydrocarbon (5-95 mass%), where this specific parameter range achieves both low GWP and acceptable cycle performance
Solution Approach 2:
The patent develops composite refrigerant formulations combining HFO-1123 with specific hydrocarbons, where the composite effect enhances cycle performance while maintaining the low GWP advantage of HFO-1123
3Object-generated harmful factors
If HFOs with low fluorine content are used, then global warming potential is reduced, but combustibility increases
Solution Approach 1:
The patent creates composite formulations where HFO-1123 is blended with hydrocarbons in specific ratios, and the combination exhibits different combustion characteristics than the individual components, achieving acceptable safety profiles
Solution Approach 2:
The patent controls the compositional parameters and identifies specific ranges where the blend ratio optimizes both low GWP and acceptable combustibility characteristics
4Object-generated harmful factors
If carbon dioxide is used as working medium, then global warming potential is reduced, but equipment pressure becomes extremely high
Solution Approach 1:
The patent changes the thermodynamic parameters by selecting HFO-1123 and its blends, which operate at pressures comparable to conventional HFC systems, avoiding the extremely high pressures associated with carbon dioxide
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 a heat cycle system with improved thermodynamic properties, enhanced cycle performance, and safety, allowing for system downsizing while minimizing ozone layer depletion and global warming potential.
Implementation Method 1
a hydrofluoroolefin (HFO) having a carbon-carbon double bond which is easily decomposed by OH radicals in the air
Data Source
Figure 1~2
Figure 3
AI summary
To provide a working medium for heat cycle, of which combustibility is suppressed, which has less influence over the ozone layer, which has less influence over global warming and which provides a heat cycle system excellent in the cycle performance (capacity), and a heat cycle system, of which the safety is secured, and which is excellent in the cycle performance (capacity). A working medium for heat cycle comprising 1,1,2-trifluoroethylene and a hydrocarbon is employed for a heat cycle system (such as a Rankine cycle system, a heat pump cycle system, a refrigerating cycle system 10 or a heat transport system).