Refrigerant Mixture Composition for Low-GWP Cooling Below -60°C
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Solution Overview
Problem
Refrigerants with low Global Warming Potential (GWP) tend to have lower cold capacity, and zeotropic mixtures with a temperature glide are undesirable due to zeotropic properties, making it challenging to achieve low temperatures while ensuring safety and environmental sustainability in cooling devices, especially in dynamic test chambers that require a wide temperature range.
Innovation Solution
A refrigerant mixture composed of up to 60 mass percent carbon dioxide, 11 to 72 mass percent pentafluoroethane, and up to 51 mass percent 2,3,3-tetrafluoropropene, which achieves a low GWP of less than 2103, is nonflammable, and has a reduced freezing point, allowing for temperatures below -60°C while maintaining safety and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a high mass fraction of carbon dioxide is used in the refrigerant mixture, then the GWP is reduced and nonflammability is achieved, but the freezing point increases making temperatures below -60°C unachievable
Solution Approach 1:
The patent changes the compositional parameters of the refrigerant mixture by limiting carbon dioxide to a maximum of 60 mass percent and introducing specific ranges for pentafluoroethane (11-72 mass percent) and 2,3,3,3-tetrafluoropropene (up to 51 mass percent). This parameter optimization resolves the contradiction by achieving the desired balance between nonflammability/GWP reduction and maintaining a sufficiently low freezing point for temperatures below -60°C
Solution Approach 2:
The patent creates a composite refrigerant mixture combining three components with complementary properties: carbon dioxide provides nonflammability and low GWP, pentafluoroethane enhances refrigeration performance and stability, and 2,3,3,3-tetrafluoropropene adjusts the temperature characteristics. This composite approach allows the mixture to simultaneously achieve environmental safety and operational temperature requirements
2Temperature
If zeotropic refrigerant mixtures with temperature glide are used, then low temperatures can be achieved, but temperature stability deteriorates requiring extensive technical restructuring
Solution Approach 1:
The patent optimizes the compositional parameters to achieve an azeotropic or near-azeotropic mixture that minimizes temperature glide while maintaining the ability to reach temperatures below -60°C. The specific mass fraction ranges are selected to balance temperature glide reduction with achievable temperature range, resolving the contradiction between temperature range and temperature stability
3Object-affected harmful factors
If refrigerants with low GWP are used, then environmental impact is reduced, but cold capacity decreases limiting temperature achievement
Solution Approach 1:
The patent combines carbon dioxide (low GWP) with pentafluoroethane and 2,3,3,3-tetrafluoropropene to create a composite refrigerant that maintains low GWP while compensating for the reduced cold capacity of pure carbon dioxide. The synergistic interaction of components restores adequate refrigeration performance for achieving temperatures below -60°C
Solution Approach 2:
The patent adjusts the mass fraction parameters to optimize the balance between environmental performance and refrigeration capacity. By limiting carbon dioxide to 60 mass percent maximum and specifying ranges for the other components, the mixture achieves both low GWP and sufficient cold capacity for the required temperature range
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 refrigerant mixture enables environmentally friendly and safe operation of cooling devices and test chambers, achieving temperatures as low as -80°C with improved temperature stability and reduced environmental impact, while being cost-effective and simple to implement.
Implementation Method 1
the refrigerant undergoes a phase transition consisting of a refrigerant mixture composed of a mass fraction of carbon dioxide, a mass fraction of pentafluoroethane and a mass fraction of at least one other component
Data Source
AI summary
A refrigerant for a cooling device comprising a cooling circuit with at least one heat exchanger, the refrigerant undergoing a phase transition in the heat exchanger, the refrigerant being a refrigerant mixture composed of a mass fraction of carbon dioxide (CO2), a mass fraction of pentafluoroethane (C2HF5) and a mass fraction of at least one other component, wherein the mass fraction of carbon dioxide in the refrigerant mixture is up to 60 mass percent, the mass fraction of pentafluoroethane being 11 to 72 mass percent, the other component being 2,3,3,3-tetrafluoropropene (C3H2F4), the mass fraction of 2,3,3,3-tetrafluoropropene being up to 51 mass percent.