Refrigerator Cooling Cycle With Gas-Liquid Separation for Higher COP
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional cooling cycle apparatuses for refrigerators face inefficiencies due to heat loss during refrigerant expansion, leading to increased dryness at the evaporator, which reduces the coefficient of performance (COP) and results in accumulated liquid-phase refrigerant that cannot be reused.
Innovation Solution
Incorporating a gas-liquid separator connected to the outlet of an expansion device to separate liquid-phase from gas-phase refrigerant, allowing for controlled heat exchange and reintegration of gas-phase refrigerant into the compressor, thereby reducing evaporator dryness and enhancing COP.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If refrigerant is expanded in the expansion device, then the refrigerant pressure and temperature are reduced, but heat loss occurs and dryness at the evaporator inlet increases
Solution Approach 1:
The gas-liquid separator is positioned immediately after the expansion device to perform preliminary separation of gas-phase and liquid-phase refrigerant before the refrigerant enters the evaporator. This preliminary action prevents heat loss in the gas-phase portion and ensures only liquid-phase refrigerant enters the evaporator, eliminating the heat loss problem during expansion.
Solution Approach 2:
The refrigerant flow is segmented into gas-phase and liquid-phase components by the gas-liquid separator. The gas-phase refrigerant is separated and redirected to mix with high-pressure refrigerant from the condenser, while the liquid-phase refrigerant proceeds to the evaporator. This segmentation allows different portions of the refrigerant to follow different paths optimized for their respective phases.
2Quantity of substance
If gas-phase refrigerant increases in the evaporator, then the refrigerant dryness increases, but the heat absorption capacity decreases
Solution Approach 1:
The gas-liquid separator performs preliminary separation before the evaporator, ensuring that only liquid-phase refrigerant enters the evaporator. This preliminary action maximizes the liquid-phase refrigerant quantity in the evaporator, thereby maximizing heat absorption capacity since liquid-phase refrigerant is the only phase that can effectively absorb heat through evaporation.
Solution Approach 2:
The gas-phase refrigerant that would otherwise be harmful (reducing heat absorption capacity) is converted into a benefit by redirecting it to mix with high-pressure refrigerant from the condenser. This creates a pre-cooled mixture that is then introduced into the evaporator, enhancing the overall heat absorption capacity while utilizing the gas-phase portion that would otherwise be wasted.
3Reliability
If liquid-phase refrigerant is separated in the accumulator, then gas-phase refrigerant is transferred to the compressor, but liquid-phase refrigerant accumulates and cannot be reused
Solution Approach 1:
The gas-liquid separator performs preliminary separation of gas-phase and liquid-phase refrigerant immediately after the expansion device, before the refrigerant reaches the evaporator or accumulator. This preliminary action ensures that gas-phase refrigerant is separated and redirected to mix with condenser outlet refrigerant, while liquid-phase refrigerant proceeds to the evaporator for efficient heat absorption, preventing liquid-phase accumulation in the accumulator and enabling complete refrigerant reuse.
Solution Approach 2:
The gas-liquid separator acts as an intermediary device between the expansion device and the evaporator/accumulator system. It mediates the refrigerant flow by separating phases and directing them to appropriate paths, preventing the harmful effect of liquid-phase accumulation in the accumulator while maintaining compressor protection through proper gas-phase delivery.
4Productivity
If the evaporator absorbs more heat, then the cooling performance increases, but the compressor work increases
Solution Approach 1:
The invention changes the parameters of the refrigerant entering the evaporator by separating and redirecting the gas-phase portion, ensuring that only liquid-phase refrigerant with optimal pressure and temperature parameters enters the evaporator. This parameter optimization maximizes heat absorption capacity per unit of refrigerant, increasing cooling performance while minimizing the refrigerant mass flow required, thereby reducing compressor work.
Solution Approach 2:
The gas-phase refrigerant that would reduce evaporator efficiency is converted into a benefit by using it to pre-cool the high-pressure refrigerant from the condenser. This creates a more efficient refrigerant mixture that requires less compressor work to achieve the same cooling effect, while the evaporator absorbs maximum heat due to receiving optimal liquid-phase refrigerant.
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 configuration lowers the dryness of the evaporator, increases the heat absorbed, reduces compressor work, and ensures all refrigerant is circulated and utilized, improving cooling efficiency and reducing power consumption.
Implementation Method 1
a gas-liquid separator for separating a liquid-phase refrigerant from gas-phase refrigerant in the refrigerant that has passed through the expansion device
Implementation Method 2
The expansion device serves to expand the refrigerant having an intermediate or lower temperature and a high pressure, into a low-temperature and low-pressure refrigerant
Implementation Method 3
the expanded refrigerant is evaporated in the evaporator. At this time, the temperature and pressure of the refrigerant decreases further. Upon evaporation of the refrigerant, the refrigerant absorbs ambient heat, thus cooling the ambient air
Implementation Method 4
The compressor serves to compress a refrigerant and discharge the refrigerant in the form of high-temperature and high-pressure gas
Implementation Method 5
the condenser serves to condense the high-temperature and high-pressure refrigerant discharged from the compressor into a liquid-phase refrigerant having an intermediate or lower temperature and a high pressure
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A cooling cycle apparatus for a refrigerator includes a first compressor (110), a condenser (120) for condensing a refrigerant compressed in the first compressor (110), a first expansion device (140) for lowering a temperature and a pressure of a portion of the condensed refrigerant, a first evaporator (160) for evaporating the refrigerant, a second expansion device (150) for lowering a temperature and a pressure of a remaining portion of the refrigerant, a gas-liquid separator (170) for separating a liquid- phase refrigerant from a gas-phase refrigerant in the refrigerant, a third expansion device (240) for lowering a temperature and a pressure of the liquid-phase refrigerant, a second evaporator (260) for evaporating the refrigerant that has passed through the third expansion device (240), and a second compressor (210) for compressing the refrigerant that has passed through the second evaporator (260) and transferring the refrigerant to the first compressor (1 10), wherein the refrigerant that has passed through the first evaporator (160) and the gas-phase refrigerant separated in the gas-liquid separator (170) are introduced into the first compressor (110) together with the refrigerant compressed in the second compressor (210).