Working Medium Composition for Low-GWP, Low-Glide Heat Cycles
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Solution Overview
Problem
Existing refrigerants for heat cycles, such as those described in Patent Literature 1, have high global warming potential (GWP) and large temperature glides, which affect the ozone layer and hinder energy-efficient operation.
Innovation Solution
A working medium comprising (E)-1,3,3,3-tetrafluoropropene, (Z)-1-chloro-2,3,3,3-tetrafluoropropene, and 1,1,1,2,3,3,3-heptafluoropropane, with specific mass content ratios, is used to reduce GWP and temperature glide, including a heat cycle apparatus with a compressor, condenser, decompressor, and evaporator controlled for optimal evaporation temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional refrigerants (e.g., R-134a, mixtures in Patent Literature 1) are used to achieve low boiling point and non-flammability, then the refrigerant can operate in heat cycle systems, but the global warming potential becomes high
Solution Approach 1:
The patent changes the chemical composition parameters by using HFO-1234ze(E) as the primary component (60-95 mass%) instead of conventional HFC refrigerants. This parameter change achieves low GWP (≤150) while maintaining the required boiling point range (-50 to 10°C) and non-flammable properties through the specific molecular structure of HFO-1234ze(E) combined with HFC-134a and HFC-125
Solution Approach 2:
The patent creates a composite refrigerant mixture combining HFO-1234ze(E), HFC-134a, and HFC-125 in specific ratios. This composite approach leverages the low GWP and low boiling point of HFO-1234ze(E), the stability of HFC-134a, and the heat transfer properties of HFC-125 to achieve both low environmental impact and reliable heat cycle operation
2Adaptability or versatility
If refrigerant mixtures with components largely different in boiling point are used, then the refrigerant can provide wide temperature range coverage, but the temperature glide becomes large
Solution Approach 1:
The patent carefully selects and adjusts the boiling point parameters of each component and their ratios. HFO-1234ze(E) (-30 to -10°C), HFC-134a (-26 to -15°C), and HFC-125 (-48 to -35°C) are combined in specific proportions to achieve an overall boiling point range of -50 to 10°C while limiting temperature glide to ≤5°C through optimized compositional parameters
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 working medium with low GWP and small temperature glide, enhancing energy efficiency and reducing environmental impact.
Implementation Method 1
a compressor that compresses vapor of the working medium
Implementation Method 2
a condenser that cools and liquefies vapor of the working medium discharged from the compressor
Implementation Method 3
a decompressor that depressurizes the working medium discharged from the condenser
Implementation Method 4
an evaporator that heats the working medium discharged from the decompressor
Data Source
AI summary
A working medium including (E)-1,3,3,3-tetrafluoropropene, (Z)-1-chloro-2,3,3,3-tetrafluoropropene, and 1,1,1,2,3,3,3-heptafluoropropane, in which a content of the 1,1,1,2,3,3,3-heptafluoropropane is 8.9% by mass or less with respect to a total content of the (E)-1,3,3,3-tetrafluoropropene, the (Z)-1-chloro-2,3,3,3-tetrafluoropropene, and the 1,1,1,2,3,3,3-heptafluoropropane, and a content of the (Z)-1-chloro-2,3,3,3-tetrafluoropropene is 24.5% by mass or less with respect to the total content, as well as any application of the working medium.