Ejector Cooling Climate Control for High-Glide Refrigerant Blends
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Solution Overview
Problem
Existing climate control systems face challenges in efficiently using refrigerants with low Global Warming Potential (GWP) that exhibit moderate to high glide or blend fractionation properties, which can lead to inefficiencies and increased energy consumption.
Innovation Solution
A climate control system that circulates a working fluid comprising a refrigerant blend with moderate to high glide, utilizing a gas-liquid separation vessel and an ejector component to manage the phase changes and fractionation of the refrigerant blend, thereby enhancing system efficiency and capacity modulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If refrigerant blends with moderate to high glide are used to reduce GWP, then environmental performance is improved, but system efficiency deteriorates due to fractionation
Solution Approach 1:
The system segments the refrigerant blend handling into distinct phases: a gas-liquid separator divides the refrigerant into vapor and liquid streams, and an ejector separates the phase change processes. This segmentation allows each component to optimize for its specific function, managing fractionation effects independently while maintaining overall system efficiency with low-GWP refrigerant blends
Solution Approach 2:
The gas-liquid separator acts as an intermediary device between the condenser and evaporator, mediating the fractionation process by separating vapor and liquid refrigerant streams. This intermediary component enables the system to handle moderate to high glide refrigerant blends by controlling the phase separation point, thereby maintaining efficiency while using environmentally friendly refrigerants
2Device complexity
If conventional vapor compression cycle is used, then system simplicity is maintained, but capacity modulation capability is limited
Solution Approach 1:
The system introduces dynamic capacity modulation capabilities by incorporating a gas-liquid separator and ejector that can adjust their operation based on system conditions. The separator can vary the split between vapor and liquid streams, and the ejector can modulate its entrainment ratio, enabling continuous capacity adjustment while maintaining relatively simple system architecture
Solution Approach 2:
The gas-liquid separator and ejector combination serves multiple functions: it separates phases, modulates capacity, manages fractionation, and controls refrigerant distribution to the evaporator. This multi-functionality allows the system to achieve enhanced adaptability without proportionally increasing complexity, as single components perform multiple critical roles
3Device complexity
If refrigerant fractionation is allowed to occur naturally, then phase change process is simplified, but temperature glide causes energy losses
Solution Approach 1:
The gas-liquid separator performs preliminary action by separating the refrigerant into distinct vapor and liquid streams before they enter the evaporator. This preliminary separation allows the system to pre-manage the fractionation process, controlling how different refrigerant components evaporate and reducing temperature glide losses during the main phase change in the evaporator
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 system effectively utilizes refrigerants with low GWP by minimizing energy losses and improving efficiency through the use of an ejector component and gas-liquid separation, allowing for better capacity modulation and reduced energy consumption.
Implementation Method 1
a gas-liquid separation vessel that receives the working fluid and separates the working fluid into a vapor stream and a liquid stream
Implementation Method 2
An ejector component is disposed downstream of the first heat exchanger and the second heat exchanger that receives the first multiphase or liquid working fluid stream and the second multiphase or vapor working fluid stream to generate a third multiphasic fluid stream
Implementation Method 3
a compressor that receives the vapor stream from the gas-liquid separation vessel and generates a pressurized vapor stream
Implementation Method 4
An expansion device receives the liquid stream from the gas-liquid separation vessel and generates a reduced pressure stream
Implementation Method 5
A first heat exchanger is disposed downstream of the compressor and receives the pressurized vapor stream to generate a first multiphase or liquid working fluid stream
Implementation Method 6
A second heat exchanger that receives the reduced pressure stream from the expansion device and at least partially vaporizes the reduced pressure stream to generate a second multiphase or vapor working fluid stream
Data Source
AI summary
Climate control systems, like reversible heat pumps, circulate a working fluid having moderate to high glide with first and second refrigerants having a difference in boiling points ≥about 10° F. (1 atm.). The system includes a gas-liquid separation vessel, a compressor, a first heat exchanger disposed downstream of the compressor that generates a first multiphase or liquid working fluid stream, an expansion device, a second heat exchanger that receives and at least partially vaporizes a reduced pressure stream from the expansion device to generate a second multiphase or vapor working fluid stream; an ejector component disposed downstream of the first and second heat exchangers that receives and mixes the first stream and the second stream to generate a third multiphasic fluid stream that is directed to the gas-liquid separation vessel; and a fluid conduit for circulating the working fluid. Methods of operating such climate control systems are also provided.