Climate control systems for use with high glide working fluids and methods for operation thereof
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Solution Overview
Problem
Conventional climate control systems face challenges in efficiently operating with refrigerant blends that have high glide, leading to fractionation issues and increased energy consumption, while also needing to reduce global warming potential and flammability.
Innovation Solution
A climate control system that circulates a working fluid comprising a blend of carbon dioxide and a hydrofluorolefin, with a difference in boiling points greater than or equal to 25°F at atmospheric pressure, utilizing a gas-liquid separation vessel, compressor, liquid pump, heat exchangers, and an expansion device to manage phase changes and refrigerant distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a refrigerant blend with high glide is used to modulate system capacity, then energy consumption is reduced, but fractionation issues occur in the system
Solution Approach 1:
The system separates the refrigerant blend into liquid and vapor phases using a gas-liquid separation vessel, allowing independent control and management of each phase to prevent fractionation issues while maintaining the benefits of high glide refrigerant blends
Solution Approach 2:
A liquid pump is introduced as an intermediary device to circulate the liquid refrigerant blend from the separation vessel through the heat exchanger, ensuring proper distribution and preventing composition instability caused by natural convection alone
2Use of energy by moving object
If conventional vapor compression cycle is used, then system operation is simple, but energy consumption is high when operating with high glide refrigerant blends
Solution Approach 1:
The conventional single-phase vapor compression cycle is segmented into separate liquid and vapor handling paths, with a gas-liquid separation vessel dividing the flow and a liquid pump handling only the liquid portion, improving efficiency while maintaining manageable complexity
Solution Approach 2:
The system changes the operating parameters by introducing a liquid pump to actively circulate liquid refrigerant, transforming the passive two-phase flow into an actively managed system that achieves better energy efficiency with high glide refrigerants
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 the high glide properties of the refrigerant blend to modulate system capacity and reduce energy consumption, while maintaining safety and environmental sustainability by using non-toxic and non-flammable refrigerants.
Implementation Method 1
a gas-liquid separation vessel that receives the working fluid and generates a vapor stream and a liquid stream
Implementation Method 2
A compressor receives the vapor stream from the gas-liquid separation vessel and generates a pressurized vapor stream
Implementation Method 3
A liquid pump that receives the liquid stream from the gas-liquid separation vessel and generates a pressurized liquid stream
Implementation Method 4
A first heat exchanger disposed downstream of the compressor that receives and cools the pressurized vapor stream and the pressurized liquid stream to generate a multiphase or liquid working fluid stream by heat exchange with air
Implementation Method 5
A second heat exchanger that receives the multiphase or liquid working fluid stream and at least partially vaporizes the multiphase or liquid working fluid by heat exchange with air
Implementation Method 6
An expansion device is disposed between the first heat exchanger and the second heat exchanger that processes the multiphase or liquid working fluid stream
Data Source
AI summary
Climate control systems and methods of operating them are provided that circulate a working fluid including a high glide refrigerant blend having first and second refrigerants with a difference in boiling points ≥about 25° F. at atmospheric pressure. The first refrigerant comprises carbon dioxide. The system includes a gas-liquid separation vessel, where a compressor receives the vapor stream and generates a pressurized vapor stream. A liquid pump receives the liquid stream and generates a pressurized liquid stream. A condenser is disposed downstream of the compressor and liquid pump and receives and cools the pressurized mixed vapor and liquid stream. An evaporator receives and at least partially vaporizes the multiphase working fluid and directs it to the gas-liquid separating vessel. An expansion device between the condenser and the evaporator processes the multiphase working fluid stream. Lastly, a fluid conduit for circulating the working fluid through the components is provided.