Air Conditioner Ejector Operation for Cooling-Heating Mixed Loads
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Solution Overview
Problem
Ejectors cannot be used in the refrigerant circuit of air conditioners during cooling-heating mixed operations, particularly when cooling operation loads exceed heating operation loads.
Innovation Solution
An air conditioner design that includes a heat-source-side unit, multiple use-side units, an intermediate unit with an ejector and gas-liquid separator, and two connection pipes, allowing the ejector to function during cooling-heating mixed operations by pressurizing refrigerant evaporated in use-side heat exchangers and controlling the flow to maintain pressure and operational efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If an ejector is installed in the refrigerant circuit to pressurize evaporated refrigerant, then the air conditioner can improve cooling efficiency and recover power during cooling operations, but the ejector cannot be used during cooling-heating mixed operations when cooling loads exceed heating loads
Solution Approach 1:
The patent makes the ejector operational status dynamic by introducing control valves (first and second on-off valves) that enable the ejector to be selectively activated or deactivated based on the operational mode. During cooling-only or cooling-dominant operations, the ejector is activated to pressurize refrigerant and improve efficiency. During heating-dominant mixed operations, the ejector is deactivated, allowing the system to adapt to different load conditions without performance degradation.
Solution Approach 2:
The patent changes the operational parameter of the ejector from static (always on or always off) to dynamic (conditionally activated). By controlling the opening/closing state of the on-off valves based on operational mode, the system optimizes the ejector's performance parameter - activating it when beneficial for cooling efficiency and deactivating it when heating performance would be compromised.
2Productivity
If the ejector functions during cooling-heating mixed operations mainly for cooling, then the air conditioner can maintain high cooling performance, but the refrigerant pressure may decrease due to insufficient driving flow
Solution Approach 1:
The patent introduces an intermediary mechanism (the first on-off valve and control system) that mediates between the ejector's cooling pressurization function and the overall refrigerant circuit pressure requirements. By controlling when the ejector activates and how much driving flow is allocated to it, the system maintains both high cooling performance and adequate refrigerant pressure throughout the circuit.
Solution Approach 2:
The patent applies partial action by allocating only a portion of the available driving flow to the ejector during cooling-heating mixed operations. The control system regulates the first on-off valve to provide sufficient driving flow to the ejector for effective refrigerant pressurization and cooling performance, while retaining enough driving flow in the main circuit to maintain overall refrigerant pressure and system stability.
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
Enables the ejector to operate effectively during cooling-heating mixed operations, enhancing the air conditioner's ability to manage varying loads and recover power, while also allowing for selective operation in different modes such as cooling only, heating only, and equivalent operations.
Implementation Method 1
The ejector is configured to pressurize the refrigerant evaporated in one or more use-side heat exchangers (31a, 31b, 31c, 31d) functioning as the evaporator by using a driving flow
Implementation Method 2
the refrigerant evaporated in one or more use-side heat exchangers (31a, 31b, 31c, 31d) functioning as the evaporator
Implementation Method 3
The refrigerant flowing out from the ejector flows into the gas-liquid separator
Data Source
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AI summary
An air conditioner (1) includes a heat-source-side unit (2), a plurality of use-side units (3a, 3b, 3c, 3d), an intermediate unit (4), and two connection pipes (5, 6). The intermediate unit (4) switches each of a plurality of use-side heat exchangers to individually function as an evaporator or a radiator of a refrigerant. The two connection pipes (5, 6) connect the heat-source-side unit (2) and the intermediate unit (4). The intermediate unit (4) has an ejector (41) and a gas-liquid separator (42). The ejector (41) pressurizes the refrigerant evaporated in the evaporator by using a driving flow. The refrigerant flowing out from the ejector (41) flows into the gas-liquid separator (42). The ejector (41) functions in a cooling-heating mixed operation mainly for cooling in which a sum of cooling operation loads of the plurality of use-side units (3a, 3b, 3c, 3d) is greater than a sum of heating operation loads of the plurality of use-side units (3a, 3b, 3c, 3d).