Multi-Air Conditioner Heat Exchanger Layout for Refrigerant Flow Control
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Solution Overview
Problem
Conventional multi-air conditioners face issues with refrigerant management, leading to inefficiencies in heating and cooling operations, particularly when indoor and outdoor temperatures are extreme, resulting in unnecessary refrigerant flow and potential freezing or inadequate cooling/heating due to mismatched load conditions.
Innovation Solution
A multi-air conditioner design featuring a multi-layered outdoor heat exchanger structure with a bypass system and electronic expansion valves, allowing for selective operation of heat exchangers based on indoor and outdoor conditions, optimizing refrigerant flow and preventing refrigerant leakage by adjusting the flow paths and valve operations according to temperature and humidity levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If all outdoor heat exchangers are operated in parallel to cope with large cooling load, then cooling capacity is improved, but refrigerant pressure becomes excessively high causing system instability
Solution Approach 1:
The outdoor heat exchangers are divided into different groups (first group connected to first compressor, second group connected to second compressor) with selective connectivity. The controller can independently control which heat exchangers are connected to which compressors, allowing the system to segment the refrigerant flow paths and avoid excessive pressure buildup while maintaining adequate cooling capacity.
2Ease of operation
If electronic expansion valve is controlled to regulate pressure and discharge temperature, then refrigerant flow control is improved, but refrigerant may remain in high-pressure gas pipeline causing inefficiency
Solution Approach 1:
The system dynamically adjusts the connectivity between outdoor heat exchangers and compressors based on real-time operating conditions. The controller monitors system state and reconfigures the refrigerant flow paths accordingly, enabling the system to adapt to varying load conditions and prevent refrigerant from stagnating in high-pressure gas pipelines, thereby maintaining high efficiency.
3Temperature
If refrigerant temperature is dropped too low for cooling operation, then cooling effect is improved, but indoor unit may freeze
Solution Approach 1:
The system provides different refrigerant temperatures to different indoor units based on their specific requirements. By selectively connecting outdoor heat exchangers to compressors and controlling refrigerant flow distribution, the system can deliver appropriately cooled refrigerant to each indoor unit without over-cooling any single unit, thereby preventing freezing while maintaining effective cooling.
4Adaptability or versatility
If multiple outdoor units are connected in parallel to cope with varying indoor loads, then adaptability to load conditions is improved, but device complexity increases
Solution Approach 1:
The outdoor heat exchangers are designed with multi-functionality, capable of serving different compressors based on operating conditions. The same heat exchanger can be connected to either the first compressor or the second compressor, eliminating the need for separate dedicated heat exchangers for each compressor and reducing overall system complexity while maintaining adaptability to varying loads.
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 solution enables efficient heating and cooling operations by optimizing heat exchanger capacity and refrigerant flow, minimizing refrigerant leakage and preventing freezing or overheating, thus improving system performance across varying load conditions.
Implementation Method 1
an outdoor heat exchanger that exchanges circulating refrigerant with outdoor air, and a four-way valve that switches a flow of refrigerant
Implementation Method 2
exchanges heat between circulating refrigerant and indoor air
Implementation Method 3
exchanges circulating refrigerant with outdoor air
Implementation Method 4
a compressor that compresses a low-temperature, low-pressure gas refrigerant into a high temperature and high pressure
Implementation Method 5
An expansion mechanism and an indoor heat exchanger that exchanges heat between circulating refrigerant and indoor air are installed on each of the plurality of indoor units
Implementation Method 6
refrigerant passing through the outdoor heat exchanger is condensed through heat exchange with ambient air
Implementation Method 7
Refrigerant expanded in the expansion mechanism is introduced into the indoor heat exchanger and evaporates as it absorbs heat from indoor air
Data Source
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AI summary
A multi-air conditioner for heating and cooling operations comprising: at least one indoor unit (B) for both cooling and heating comprising an indoor heat exchanger (11 ); an outdoor unit (A) for both cooling and heating comprising a compressor (53, 54), a plurality of outdoor heat exchangers (A1 to A3), and a switching unit (62) disposed on a discharge side of the compressor to switch the flow of a refrigerant; and a distributor (C) disposed between the outdoor unit (A) for both cooling and heating and the at least one indoor unit (B) for both cooling and heating, for distributing the refrigerant, wherein the plurality of outdoor heat exchangers (A1 to A3) in the outdoor unit (A) for both cooling and heating comprises: a first heat exchanger (A1), one end of which is connected to the switching unit (62), and the other end of which is connected to the distributor (C); a second heat exchanger (A2) stacked over or under the first heat exchanger (A1), one end of which is couplable to or decouplable from the other end of the first heat exchanger (A1), and the other end of which is connected to the distributor (C); and a third heat exchanger (A3) stacked over or under the second heat exchanger (A3), one end of which is connected to the discharge side of the compressor (53, 54), and the other end of which is connected to the indoor unit (B).