Multi-unit air conditioning system
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Solution Overview
Problem
In multi-type air conditioning systems, indoor units that perform cooling operations year-round face reduced cooling capacity due to refrigerant flow imbalances and freezing issues, especially during winter, requiring complex control settings and increased costs to maintain performance.
Innovation Solution
The system incorporates an evaporating pressure adjustment mechanism in cooling-only indoor units and a cooling/heating operation switching mechanism in dual-operation units, utilizing supercooling and overheating heat exchangers to manage refrigerant flow and pressure, preventing freezing and ensuring continuous cooling capacity without software-specific settings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the outdoor unit and indoor cooling unit both function as evaporators with different suction temperatures, then the system can provide both heating and cooling operations simultaneously, but the evaporating temperature is stabilized based on the lowest temperature causing the heat exchanger to freeze and cooling operation to be interrupted
Solution Approach 1:
The patent segments the refrigerant circulation system into separate high-pressure and low-pressure gas pipes, allowing independent temperature control for heating and cooling operations. The high-pressure gas pipe carries refrigerant for heating operations while the low-pressure gas pipe carries refrigerant for cooling operations, enabling simultaneous operations without freezing issues.
Solution Approach 2:
The patent introduces a pressure control valve as an intermediary device in the high-pressure gas pipe between the outdoor unit and the switching mechanism. This valve regulates the pressure of refrigerant entering the heating operation, preventing it from dropping to levels that would cause freezing in the cooling heat exchanger during simultaneous operations.
2Productivity
If control methods are used to ensure cooling capacity by opening expansion valve or increasing compressor rotation number, then cooling capacity is maintained, but complex control settings are required for each system configuration increasing product costs
Solution Approach 1:
The patent replaces complex software control mechanisms with a simple mechanical pressure control valve. Instead of using control algorithms to dynamically adjust expansion valve opening or compressor speed based on system configuration, the pressure control valve passively maintains appropriate refrigerant pressure through its mechanical design, eliminating the need for complex control systems.
Solution Approach 2:
The patent changes the pressure parameter of the refrigerant in the high-pressure gas pipe by introducing the pressure control valve. This valve maintains the refrigerant pressure within an appropriate range, ensuring that the refrigerant does not expand too much in the cooling heat exchanger during simultaneous heating and cooling operations, thereby maintaining cooling capacity without complex control.
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 maintains continuous cooling operations, enhances refrigerant circulation, and reduces costs by eliminating the need for complex software settings, ensuring reliable and efficient cooling capacity for indoor units performing year-round cooling.
Implementation Method 1
an outdoor heat exchanger that performs heat exchange between outside air and a refrigerant
Implementation Method 2
indoor heat exchangers that perform heat exchange between indoor air and a refrigerant
Implementation Method 3
an outdoor unit includes a compressor
Implementation Method 4
an evaporating pressure adjustment mechanism that adjusts evaporating pressure in the indoor heat exchanger
Implementation Method 5
a cooling/heating operation switching mechanism that switches a flow direction of the refrigerant in the high-pressure gas pipe, the low-pressure gas pipe, and the liquid pipe
Data Source
Figure 1
Figure 2A~2B
Figure 3A~3B
AI summary
A sufficient cooling capacity can be easily ensured with low costs even when an indoor unit that always performs a cooling operation is provided in an air conditioning system including a plurality of indoor units. An indoor unit 3c that always performs a cooling operation includes a gas pipe pressure control kit 100 including a plurality of electromagnetic valves 101a, 101b and 101c, controls opening/closing of the electromagnetic valves 101a, 101b and 101c according to a suction temperature of a refrigerant, and thus adjusts pressure loss of the refrigerant guided via an indoor heat exchanger 40 through a low-pressure gas pipe 7 to an outdoor unit 1 and adjusts evaporating pressure of the refrigerant in the indoor heat exchanger 40. This can prevent a suction temperature from dropping to below zero, and prevent the indoor heat exchanger 40 from freezing in an indoor unit 3c that performs the cooling operation even when an outside air temperature is low, the other indoor unit 3 performs the heating operation, and the outdoor unit functions as an evaporator.