Systems and Methods for Regenerative Ejector-Based Cooling Cycles
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Solution Overview
Problem
Conventional two-stage cooling cycles require multiple stages and refrigerants, increasing complexity and reducing energy efficiency, while existing single-stage systems lack effective subcooling mechanisms.
Innovation Solution
A single-stage regenerative ejector-based cooling cycle that utilizes an ejector to mix and separate refrigerant phases, incorporating a flash tank and sub-cooler to achieve subcooling without a second stage, reducing equipment and enhancing energy efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a conventional two-stage cooling cycle is used to achieve subcooling, then subcooling performance is improved, but system complexity and the number of components increase
Solution Approach 1:
The patent segments the subcooling function into two parts: the ejector provides flash gas removal and partial subcooling, while the suction line heat exchanger provides additional subcooling. This segmentation allows achieving the subcooling temperature target with a single-stage system rather than requiring a complex two-stage system.
Solution Approach 2:
The ejector in the single-stage system performs multiple functions: it acts as a flash gas remover, provides refrigerant mixing, and contributes to subcooling. The suction line heat exchanger simultaneously serves as both a subcooling device and a superheating device for the compressor suction line, reducing the need for separate dedicated components.
2Temperature
If a conventional two-stage cooling cycle is used to achieve subcooling, then subcooling performance is improved, but the number of refrigerants and equipment increases
Solution Approach 1:
The single-stage system uses one refrigerant circulating through all components including the ejector, flash tank, sub-cooler, and evaporator. The multi-functional design allows this single refrigerant to serve all thermal and phase change requirements that would traditionally require multiple refrigerants in a two-stage system.
3Device complexity
If a single-stage cooling cycle is used to reduce complexity, then device complexity is reduced, but subcooling capability is insufficient
Solution Approach 1:
The suction line heat exchanger acts as an intermediary device that transfers heat from the sub-cooled liquid refrigerant to the superheated vapor refrigerant. This intermediary heat exchange mechanism enables effective subcooling in the single-stage system without requiring the complex heat exchanger arrangements of a two-stage system.
4Device complexity
If a single-stage cooling cycle with ejector is used, then equipment quantity is reduced, but compression energy efficiency may worsen
Solution Approach 1:
The ejector changes the pressure and temperature parameters of the refrigerant through its expansion and mixing processes. By properly designing the ejector geometry and operating parameters, the system achieves flash gas removal and subcooling effects that reduce the compression work required, offsetting any energy consumption in the ejector itself.
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 achieves energy efficiency comparable to two-stage cycles with fewer components, lower compression energy, and improved coefficient of performance.
Implementation Method 1
an ejector for mixing a condensed liquid form of the refrigerant and a first vaporized form of the refrigerant to form a two-phase form of the refrigerant
Implementation Method 2
a flash tank in fluid communication with the ejector for separating the two-phase form of the refrigerant from the ejector into a second vaporized form of the refrigerant and a liquid form of the refrigerant
Implementation Method 3
a sub-cooler connected to the ejector by a vaporized refrigerant line for cooling a portion of the liquid form of the refrigerant from a liquid refrigerant line fluidly connected to the flash tank
Implementation Method 4
an evaporator in fluid communication with the sub-cooler and the flash tank for producing a third vaporized form of the refrigerant
Implementation Method 5
a compressor connected to the flash tank for compressing the second vaporized form of the refrigerant
Implementation Method 6
a heat exchanger connected to the compressor and the ejector for cooling a compressed vaporized form of the refrigerant and producing the condensed liquid form of the refrigerant
Data Source
AI summary
Systems and methods for regenerative ejector-based cooling cycles that utilize an ejector as the motivating force in a cooling loop to regeneratively sub-cool a refrigerant in a single-stage cooling cycle.