Ejector Refrigerant Cycle With Two-Phase Throttle Decompression
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Solution Overview
Problem
The ejector refrigerant cycle device with an inner heat exchanger faces inefficiencies due to insufficient decompression of the refrigerant at the second evaporator, leading to inadequate refrigeration capacity, as the refrigerant entering the throttle mechanism is in a super-cooled state, increasing its density and reducing pressure reduction effectiveness.
Innovation Solution
The device incorporates a decompression mechanism that handles refrigerant in a vapor-liquid two-phase state, allowing for increased pressure reduction and enthalpy difference across the evaporators, enhancing cycle efficiency by using a capillary tube as the throttle mechanism and an inner heat exchanger that radiates heat while decompressing the refrigerant.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the refrigerant is cooled to a super-cooled state in the inner heat exchanger, then the heat exchange efficiency is improved, but the density of the refrigerant increases causing insufficient decompression at the throttle mechanism
Solution Approach 1:
The patent changes the thermodynamic state parameter of the refrigerant from super-cooled to vapor-liquid two-phase state before it enters the throttle mechanism. This parameter change reduces the refrigerant density, thereby improving decompression effectiveness while maintaining heat exchange efficiency through the inner heat exchanger.
Solution Approach 2:
The patent dynamically adjusts the cooling degree in the inner heat exchanger to prevent complete super-cooling. By controlling the heat exchange process to maintain vapor-liquid two-phase state rather than full super-cooling, the system achieves both efficient heat exchange and adequate decompression capability.
2Quantity of substance
If the refrigerant density is increased by super-cooling, then the mass flow amount through the throttle mechanism increases, but the passage resistance decreases leading to insufficient pressure reduction
Solution Approach 1:
The patent changes the refrigerant state parameter from super-cooled liquid to vapor-liquid two-phase state. This parameter change optimizes the balance between mass flow amount and passage resistance, ensuring sufficient pressure reduction while maintaining adequate mass flow through the throttle mechanism.
3Stress or pressure
If the refrigerant evaporation pressure at the second evaporator is not decreased enough, then the system operates with higher pressure, but the refrigeration capacity of the second evaporator is insufficient
Solution Approach 1:
The patent changes the refrigerant state to vapor-liquid two-phase state before throttle mechanism entry, which improves decompression effectiveness and decreases the refrigerant evaporation pressure at the second evaporator. This parameter change enables the second evaporator to achieve sufficient refrigeration capacity.
Solution Approach 2:
The patent performs preliminary cooling in the inner heat exchanger to create vapor-liquid two-phase state before the refrigerant enters the throttle mechanism. This preliminary action prepares the refrigerant in an optimal state for decompression, ensuring adequate pressure reduction and refrigeration capacity at the second 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
This approach effectively increases the refrigeration capacity and cycle efficiency by ensuring appropriate decompression of the refrigerant without compromising the system's performance, even with low dryness levels of the vapor-liquid two-phase refrigerant.
Implementation Method 1
a first decompression means for decompressing and expanding refrigerant of the second stream branched from the branch portion
Implementation Method 2
an evaporator for evaporating refrigerant on a downstream side of the decompression means
Implementation Method 3
an ejector that has a nozzle portion for decompressing and expending refrigerant of the first stream from the branch portion
Implementation Method 4
the pressure of refrigerant to be drawn by the compressor is increased
Implementation Method 5
an inner heat exchanger for exchanging heat between high-temperature and high-pressure refrigerant on the downstream side of the radiator and low-temperature and low-pressure refrigerant on the suction side of the compressor
Implementation Method 6
a radiator for radiating heat of high-temperature and high-pressure refrigerant discharged from the compressor
Data Source
AI summary
An ejector refrigerant cycle device includes a radiator for radiating heat of high-temperature and high-pressure refrigerant discharged from a compressor, a branch portion for branching a flow of refrigerant on a downstream side of the radiator into a first stream and a second stream, an ejector that includes a nozzle portion for decompressing and expending refrigerant of the first stream from the branch portion, a decompression portion for decompressing and expanding refrigerant of the second stream from the branch portion, and an evaporator for evaporating refrigerant on a downstream side of the decompression portion. The evaporator has a refrigerant outlet coupled to the refrigerant suction port of the ejector. Furthermore, a refrigerant radiating portion is provided for radiating heat of refrigerant while the decompression portion decompresses and expands refrigerant. For example, the refrigerant radiating portion is provided in an inner heat exchanger.