Ejector cycle
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Solution Overview
Problem
Ejector refrigeration systems face inefficiencies in power consumption and refrigeration effect due to the need for superheated refrigerant production and the complexity of controlling the ejector cycle, particularly in varying operating conditions.
Innovation Solution
A dual-compressor system with two ejectors and a separator, along with a controllable valve and additional heat exchangers, allows for continuous variable control of compressor speed and ejector operation, optimizing refrigerant flow and pressure ratios to enhance efficiency and adapt to different temperature conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single compressor and ejector system is used, then the system structure is simple, but the power consumption is high and refrigeration effect is insufficient
Solution Approach 1:
The system divides the compression and ejector functions into two separate compressors (first and second compressors) and two separate ejectors (first and second ejectors). This segmentation allows each component to operate more efficiently at its optimal point, reducing overall power consumption while improving refrigeration effect.
Solution Approach 2:
The patent implements continuous variable control of compressor speeds and ejector operations, allowing the system to dynamically adjust to varying operating conditions. This dynamic control optimizes the refrigeration cycle efficiency across different temperature and load conditions, reducing power consumption.
2Reliability
If superheated refrigerant production is required, then the refrigeration cycle can be maintained, but the power consumption increases
Solution Approach 1:
The patent changes the operational parameters by using two separate compressors with different discharge pressures, allowing the refrigerant to reach the required state without excessive superheating. The first compressor discharges at a higher pressure to the condenser, while the second compressor discharges at a lower pressure to the evaporator, optimizing the cycle efficiency.
3Productivity
If the ejector cycle is controlled for varying operating conditions, then the refrigeration effect improves, but the control complexity increases
Solution Approach 1:
The system uses continuous variable control mechanisms for both compressors and ejectors, enabling smooth adjustment of operating parameters to match varying refrigeration demands. This dynamic control allows the system to optimize performance across different conditions without requiring complex discrete control systems.
Solution Approach 2:
The dual-compressor dual-ejector configuration provides multi-functionality, where the system can operate in different modes depending on the refrigeration demand. The compressors and ejectors can be independently controlled to handle various operating conditions, from partial to full load, simplifying the overall control strategy.
4Use of energy by moving object
If a dual-compressor system with two ejectors is used, then power consumption is reduced and refrigeration effect is improved, but the device complexity increases
Solution Approach 1:
The system segments the refrigeration function into two independent but coordinated loops, each with its own compressor and ejector. This segmentation allows each subsystem to be simpler and more efficient, while the overall system achieves superior performance through their coordinated operation.
Solution Approach 2:
The patent merges the two compressor-ejector subsystems through a shared refrigerant circuit, where the first compressor discharges to the condenser and the second compressor discharges to the evaporator. The merging of these subsystems creates a synergistic effect that reduces total power consumption while improving refrigeration effect.
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 reduces power consumption, improves refrigeration effect, and allows for efficient operation across a range of temperatures by optimizing the refrigerant flow and pressure ratios, enabling efficient cooling in refrigerated containers and trailers.
Implementation Method 1
a heat rejection heat exchanger, a first ejector
Implementation Method 2
The primary refrigerant flow 103 enters the inlet 40 and then passes into a convergent section 104 of the motive nozzle 100. It then passes through a throat section 106 and an expansion (divergent) section 108 through an outlet 110 of the motive nozzle 100. The motive nozzle 100 accelerates the flow 103 and decreases the pressure of the flow.
Implementation Method 3
The outer member includes a mixer having a convergent section 114 and an elongate throat or mixing section 116. The motive nozzle outlet 110 is positioned within the convergent section 114. As the flow 103 exits the outlet 110, it begins to mix with the flow 112 with further mixing occurring through the mixing section 116 which provides a mixing zone.
Implementation Method 4
The separator has an inlet coupled to the outlet of the first ejector to receive refrigerant from the first ejector. The separator has a gas outlet coupled to the secondary inlet of the second ejector
Implementation Method 5
a heat absorption heat exchanger
Implementation Method 6
The flow 112 passes as a liquid to the expansion valve 70. The flow 112 may be expanded by the valve 70 (e.g., to a low quality (two-phase with small amount of vapor))
Implementation Method 7
Within the evaporator 64, the refrigerant absorbs heat from a heat transfer fluid (e.g., from a fan-forced air flow or water or other liquid)
Data Source
AI summary
A system (200; 250; 270) has first (220) and second (222) compressors, a heat rejection heat exchanger (30), first (38) and second (202) ejectors, a heat absorption heat exchanger (64), and a separator (48). The heat rejection heat exchanger is coupled to the second compressor to receive refrigerant compressed by the second compressor. The first ejector has a primary inlet (40) coupled to the heat rejection exchanger to receive refrigerant, a secondary inlet (42), and an outlet (44). The second ejector has a primary inlet (204) coupled to the heat rejection heat exchanger to receive refrigerant, a secondary inlet (206), and an outlet (208). The separator has an inlet (50) coupled to the outlet (44) of the first ejector to receive refrigerant from the first ejector. The separator has a gas outlet (54) coupled to the secondary inlet (206) of the second ejector via the first compressor (220) to deliver refrigerant to the second ejector. The separator has a liquid outlet (52) coupled to the secondary inlet (42) of the first ejector via the heat absorption heat exchanger to deliver refrigerant to the first ejector.