Heat Pump Refrigerant Design for Geometric Isomer Stability Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Substances with geometric isomers, which have different three-dimensional structures and varying physical properties, pose challenges in refrigeration cycles as they can isomerize at high temperatures, leading to unstable operation in heat pumps designed for single refrigerants.
Innovation Solution
Designing a heat pump with a closed circuit filled with a refrigerant containing a geometric isomer, where the upper limit of stable temperature is determined to prevent isomerization, and using a mixed refrigerant with a geometric isomer concentration at or above the equilibrium concentration to stabilize isomerization, ensuring no further changes in physical properties occur.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a refrigerant substance with a carbon-carbon double bond is used to achieve low GWP, then environmental performance is improved, but isomerization occurs at high temperatures leading to unstable operation
Solution Approach 1:
The patent controls the concentration parameter of the geometric isomer in the refrigerant mixture. By maintaining the geometric isomer at specific concentration ranges (5-50 mol% in some embodiments, or 10-40 mol% in others), the system prevents isomerization of the remaining refrigerant substance while preserving the low GWP benefits. This parameter control stabilizes the refrigerant composition during high-temperature operation.
Solution Approach 2:
The patent creates a composite refrigerant system by mixing the refrigerant substance with its geometric isomer. This composite mixture leverages the stabilizing effect of the geometric isomer to prevent further isomerization reactions, while maintaining the desirable low-GWP properties of the original refrigerant substance. The composite approach transforms a stability problem into a controlled mixture solution.
2Adaptability or versatility
If the heat pump operates at higher temperatures to expand application range, then versatility is improved, but isomerization of the refrigerant substance is triggered
Solution Approach 1:
The patent modifies the operational parameters by establishing specific temperature limits for the heat pump system based on the refrigerant mixture composition. By controlling the operating temperature to remain below the isomerization threshold and adjusting the geometric isomer concentration, the system enables higher temperature operation than conventional single-substance refrigerants while maintaining composition stability.
Solution Approach 2:
The patent pre-stabilizes the refrigerant mixture by incorporating the geometric isomer before operation. This beforehand cushioning effect creates a buffer that prevents isomerization reactions during high-temperature operation, allowing the heat pump to operate in expanded temperature ranges without composition degradation.
3Device complexity
If a single refrigerant substance is used to simplify the system, then device complexity is reduced, but the refrigerant cannot be used due to isomerization issues
Solution Approach 1:
The patent resolves the contradiction by creating a simple binary composite refrigerant system consisting of the refrigerant substance and its geometric isomer. This approach maintains minimal system complexity while ensuring reliability, as the geometric isomer acts as a stabilizing component that prevents further isomerization reactions.
Solution Approach 2:
The patent optimizes the concentration parameter of the geometric isomer to achieve a balance between simplicity and reliability. By selecting specific concentration ranges, the system maintains a simple two-component mixture while ensuring stable operation and preventing isomerization-related reliability issues.
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
This approach allows for the stable use of geometric isomers as refrigerants in heat pumps, maintaining a stable heat cycle even at temperatures where isomerization would typically occur, by controlling the geometric isomer concentration and temperature to prevent isomerization.
Implementation Method 1
there is one in which part of a single substance changes to a geometric isomer that differs in physical properties (particularly boiling point) by being exposed to a high temperature environment for a long time (hereinafter referred to as isomerization)
Implementation Method 2
a condenser, an expansion valve, and an evaporator in this order
Implementation Method 3
a condenser, an expansion valve, and an evaporator in this order
Data Source
AI summary
It is an object of the present invention to provide a heat pump that can use, as a refrigerant, a substance with which a geometric isomer exists, and a method for designing the same. The present invention is a method for designing a heat pump (1) whose closed circuit configured by connecting a compressor (2), a condenser (3), an expansion valve (4), and an evaporator (5) in this order is filled with a refrigerant containing a refrigerant substance with which a geometric isomer may exist, the method including obtaining an upper limit of stable temperature at which isomerization of the refrigerant substance does not proceed, and setting an upper limit usage temperature of the heat pump (1) so as not to exceed the upper limit of the stable temperature.