Air conditioning device, ejector used therein, and method for controlling air conditioning device
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Solution Overview
Problem
Conventional air conditioning devices using two ejectors face challenges in maximizing pressure increasing effect across varying refrigerant flow rates due to non-optimized ejector shapes for different flow rates, leading to inefficient energy use.
Innovation Solution
The air conditioning device incorporates multiple ejectors connected in parallel, each optimized for specific refrigerant flow rates, with adjustable nozzles and valves to control refrigerant flow based on operation conditions, ensuring optimal performance across all flow rate ranges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If refrigerant flows simultaneously through two ejectors to handle large refrigerant flow rates, then the refrigeration capacity is maintained, but the pressure increasing effect cannot be maximized because the ejectors are not optimized for varying flow rates
Solution Approach 1:
The system divides the single ejector function into multiple ejectors (first ejector and second ejector), each optimized for specific refrigerant flow rate ranges. The controller selectively activates one ejector based on the required refrigeration capacity, ensuring optimal pressure increasing effect across all operating conditions.
Solution Approach 2:
The system dynamically switches between different ejectors based on operating conditions. The controller adjusts which ejector is active according to the refrigerant flow rate requirements, allowing the system to adapt and maintain optimal pressure increasing effect across varying load conditions.
2Device complexity
If one ejector has a fixed opening degree to simplify control, then the device complexity is reduced, but the ability to control refrigerant flow rate precisely is limited
Solution Approach 1:
The control function is segmented between multiple ejectors with different opening degree configurations. One ejector has a fixed opening degree for simplicity, while the other has an adjustable opening degree for precise control. This segmentation allows the system to achieve both simplicity and controllability.
Solution Approach 2:
The system uses multiple ejectors where each can serve different functional roles - one for high flow rate applications with fixed opening, and another for variable flow rate applications with adjustable opening. This multi-functionality allows the system to handle diverse operating conditions effectively.
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 maximizes pressure increasing effect across all operation modes, enhancing energy efficiency and refrigerant flow management.
Implementation Method 1
since the ejector converts the expansion loss generated in the conventional expansion valve into the kinetic energy and uses the kinetic energy to increase the pressure
Data Source
AI summary
An air conditioning device includes a plurality of ejectors which have a refrigerant circuit including a compressor, a condenser and an evaporator, are connected in parallel to the refrigerant circuit, and are formed so as to each have a different maximum refrigerant flow, and a control unit which, according to a driving condition of the air conditioning device, controls so that the refrigerant flows to one ejector among the plurality of ejectors, and the refrigerant does not flow to the rest of the ejectors.