Multi-Air Conditioner Leak Shut-Off Layout for Refrigerant Loss
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional multi-air conditioners face challenges in minimizing refrigerant leakage, particularly when leaks occur between indoor units and shut-off valves, leading to potential safety hazards and increased refrigerant loss due to the difficulty in determining leak positions and the inefficiency of existing shut-off mechanisms.
Innovation Solution
The proposed multi-air conditioner incorporates a configuration with shut-off valves positioned outside the indoor space, utilizing a subcooling unit and accumulator to rapidly decrease refrigerant pipeline pressure upon leak detection, combined with a distributor that manages refrigerant flow to minimize leakage by using low-pressure and high-pressure headers and valves to control refrigerant distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If shut-off valves are installed inside the indoor space, then refrigerant leakage can be blocked quickly, but the valves may be exposed to harmful refrigerant and reduce reliability
Solution Approach 1:
The shut-off valve is extracted from the indoor space and relocated to the outdoor unit. This removes the valve from the harmful environment where refrigerant leaks occur, allowing it to operate in cleaner conditions and maintain higher reliability while still achieving the function of blocking refrigerant flow when needed.
2Reliability
If shut-off valves are positioned outside the indoor space, then the valves are protected from refrigerant harm, but the response time to block leaks increases
Solution Approach 1:
The shut-off valve is pre-positioned at the outdoor unit where refrigerant lines enter the building. This preliminary positioning allows the valve to block leaks at the source or entry point, preventing refrigerant from entering the indoor space in the first place, thus achieving both fast response and protection from harmful exposure.
3Loss of substance
If refrigerant pipeline pressure is not reduced quickly, then refrigerant continues to leak at high pressure, but reducing pressure requires additional system complexity
Solution Approach 1:
The system uses its existing accumulator and expansion valves to automatically reduce refrigerant pressure when a leak is detected. The accumulator stores low-pressure refrigerant and the expansion valve controls pressure reduction without requiring external or additional pressure reduction equipment, achieving refrigerant loss mitigation through self-service using existing components.
4Stability of the object's composition
If the accumulator is positioned to receive refrigerant from the outdoor heat exchanger, then refrigerant can be stored for pressure equalization, but the system complexity increases
Solution Approach 1:
The accumulator is merged into the existing refrigerant circulation path between the outdoor heat exchanger and the expansion valve. By combining the storage function with the existing high-pressure liquid line, the system achieves pressure stabilization and refrigerant storage without adding separate, independent storage systems, thus minimizing additional complexity while maintaining pressure 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
This configuration significantly reduces refrigerant leakage by quickly lowering pipeline pressure and optimizing shut-off valve placement, minimizing refrigerant loss and ensuring user safety by positioning shut-off valves outside the indoor space.
Implementation Method 1
a subcooling unit (68) connected to the liquid pipe connecting pipeline (134) to cool the refrigerant in the liquid pipe connecting pipeline
Implementation Method 2
the subcooling unit comprises: a subcooling heat exchanger (68a)
Implementation Method 3
a subcooling expansion valve (68c) disposed on the subcooling bypass pipeline (68b) to selectively expand a refrigerant flowing therein
Implementation Method 4
Each of the plurality of outdoor units is provided with a compressor that compresses a low-temperature, low-pressure gas refrigerant into a high temperature and high pressure
Implementation Method 5
an outdoor heat exchanger that exchanges circulating refrigerant with outdoor air, and an expansion mechanism and an indoor heat exchanger that exchanges heat between circulating refrigerant and indoor air
Data Source
Figure 1A~1B
Figure 2
Figure 3
AI summary
A multi-air conditioner for heating and cooling may include at least one indoor unit (B1,B2) installed in an indoor space (210,220) and comprising an indoor heat exchanger (B1,B2) and an indoor expansion valve (12); an outdoor unit (A) connected to the at least one indoor unit via a refrigerant pipeline (134,138) and comprising an outdoor heat exchanger (A1,A2), a compressor (53,54), an outdoor expansion valve (65,66), and a four-way valve (110,120); and at least one leak shut-off valve (313,314) provided on the refrigerant pipeline, that blocks a flow of refrigerant in the refrigerant pipeline when a refrigerant leak from the refrigerant pipeline occurs in the indoor space. The outdoor unit may decrease a pressure of the refrigerant pipeline when a refrigerant leak occurs from the refrigerant pipeline. Therefore, it is possible to minimize an amount of refrigerant leakage when there is a refrigerant leak in the indoor space.