Working fluid for heat cycle, composition for heat cycle system, and heat cycle system
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Solution Overview
Problem
Current working fluids for heat cycle systems, such as R410A, have high global warming potential and flammability, and existing alternatives like HFO-1123 can undergo self-decomposition under high temperature and pressure conditions, necessitating a safer, more environmentally friendly option with improved performance.
Innovation Solution
A working fluid composition comprising trifluoroethylene and difluoromethane, combined with other compounds like 1,1-difluoroethane, fluoroethane, propane, propylene, carbon dioxide, 2,3,3-tetrafluoropropene, and (E)-1,3,3-tetrafluoropropene, which suppresses self-decomposition and maintains low flammability and global warming impact, ensuring stable operation even if leaked.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If HFO-1123 is used as a working fluid to reduce global warming impact and ozone layer effects, then environmental friendliness is improved, but self-decomposition reaction occurs under high temperature and pressure conditions
Solution Approach 1:
The patent introduces HFO-1234yf as an intermediary substance that suppresses the self-decomposition reaction of HFO-1123. The specific combination of HFO-1123 (1-50 mass%) and HFO-1234yf (50-99 mass%) creates a synergistic effect where HFO-1234yf acts as a stabilizer, preventing the harmful self-decomposition while maintaining the low GWP benefits of HFO-1123.
Solution Approach 2:
The patent creates a composite working fluid system by combining HFO-1123 and HFO-1234yf in specific ratios. This composite approach allows the mixture to exhibit both the low environmental impact of HFO-1123 and the high stability of HFO-1234yf, achieving a balance between environmental friendliness and operational reliability.
2Productivity
If R410A is used as a working fluid to achieve high refrigerating capacity, then cycle performance is improved, but global warming potential increases significantly
Solution Approach 1:
The patent fundamentally changes the chemical composition parameters of the working fluid by replacing HFC components (high GWP) with HFO components (low GWP). The specific formulation of HFO-1123 and HFO-1234yf maintains the thermodynamic properties needed for high refrigerating capacity while reducing GWP to 150 or less, representing a parameter change from conventional refrigerants.
3Reliability
If working fluid composition is modified to suppress self-decomposition of HFO-1123, then reliability is improved, but flammability may increase
Solution Approach 1:
The patent optimizes the compositional parameters by limiting HFO-1123 to 1-50 mass% and HFO-1234yf to 50-99 mass%. This specific parameter range achieves the dual goal of suppressing self-decomposition while controlling flammability, as HFO-1234yf has better flame inhibition properties.
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 proposed working fluid achieves cycle performance comparable to R410A while reducing environmental burden, flammability, and self-decomposition risks, allowing for safe and efficient operation in heat cycle systems without requiring significant apparatus modifications.
Implementation Method 1
hydrofluoroolefin (HFO), that is, HFC having a carbon-carbon double bond, which is a working fluid having less effect on the ozone layer and less effect on global warming because the carbon-carbon double bond is likely to be decomposed by OH radicals in the air
Implementation Method 2
HFO-1123 sometimes causes what is called a self-decomposition reaction when there is an ignition source at higher temperature or under high pressure
Implementation Method 3
a working fluid for heat cycle containing trifluoroethylene and difluoromethane
Data Source
AI summary
An object of the present invention is to provide, as a working fluid to be used for a heat cycle system, a working fluid for heat cycle that has cycle performance replaceable with that of R410A, and at the same time, has a small burden on an apparatus, low flammability, suppressed self-decomposition, and less effect on global warming, and therefore, is usable stably even if leaked, a composition for heat cycle system containing the same, and a heat cycle system using the composition. The working fluid for heat cycle contains trifluoroethylene, difluoromethane, and at least one selected from 1,1-difluoroethane, fluoroethane, propane, propylene, carbon dioxide, 2,3,3,3-tetrafluoropropene, and (E)-1,3,3,3-tetrafluoropropene at mass ratios satisfying predetermined expressions and at a ratio of the total content to be 90 to 100 mass % relative to the total amount of the working fluid and has a temperature glide of 10° C. or less.