Outdoor unit and method for controlling same
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Solution Overview
Problem
Existing refrigeration systems face challenges in reducing discharge temperature without increasing the bypass amount of refrigerant through the supercooler, which can lead to decreased refrigerating performance and system efficiency, especially under high outdoor temperatures.
Innovation Solution
The outdoor unit incorporates a low pressure side compressor, a high pressure side compressor, an outdoor heat exchanger, a heat recovery unit, and a supercooler with a supercooling expansion valve, a supercooling heat exchanger, a bypass valve, and an injection valve. The system measures discharge temperatures and adjusts the operation of the supercooling expansion valve, bypass valve, and injection valve to reduce discharge temperatures while minimizing refrigerant bypass.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the supercooling performance of the supercooler is increased under high outdoor temperature, then the discharge temperature is reduced, but the amount of refrigerant bypassed to the compressor increases
Solution Approach 1:
The patent divides the refrigerant flow path into multiple segments: a first path through the supercooler for supercooling, a second path bypassing the supercooler, and a third path through the heat recovery unit. This segmentation allows selective routing of refrigerant flows to achieve both supercooling and maintain compressor inlet temperature without excessive bypass.
Solution Approach 2:
The heat recovery unit acts as an intermediary component between the supercooler and the compressor. It recovers heat from the high-temperature refrigerant and uses it to preheat the refrigerant before it enters the compressor, thereby compensating for the cooling effect of the supercooler and maintaining optimal compressor inlet temperature.
2Temperature
If the amount of refrigerant bypassed through the supercooler is increased, then the discharge temperature is reduced, but the system efficiency is lowered
Solution Approach 1:
The patent converts the waste heat from the high-temperature refrigerant discharge into a useful resource by routing it through the heat recovery unit. This recovered heat is then used to preheat the refrigerant before compression, transforming what would be energy loss into a beneficial heating function that improves overall system efficiency.
Solution Approach 2:
The system recovers heat energy that would otherwise be discarded from the refrigerant discharge. The heat recovery unit captures this thermal energy and redirects it to the refrigerant stream before compression, ensuring that energy is reused rather than wasted, thereby maintaining high system efficiency.
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 effectively reduces the discharge temperature of the compressors without reducing the refrigerant flow into the refrigerator, thereby maintaining or improving refrigerating performance and system efficiency even under high outdoor temperatures.
Implementation Method 1
a low pressure side compressor for compressing a refrigerant
Implementation Method 2
a high pressure side compressor for compressing the refrigerant compressed by the low pressure side compressor
Implementation Method 3
an outdoor heat exchanger for condensing the refrigerant compressed by the high pressure side compressor
Implementation Method 4
a heat recovery unit for cooling the refrigerant condensed in the outdoor heat exchanger by exchanging heat with the refrigerant evaporated in the air conditioner
Implementation Method 5
a supercooling expansion valve for expanding a part of the refrigerant cooled in the heat recovery unit
Implementation Method 6
a supercooling heat exchanger for cooling another part of the refrigerant cooled in the heat recovery unit by exchanging heat with the refrigerant expanded in the supercooling expansion valve
Data Source
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AI summary
The present invention relates to an outdoor unit which is connected to a refrigerator and has two compressors that are connected in series, and a control method thereof. The outdoor unit according to an embodiment of the present invention includes a low pressure side compressor for compressing a refrigerant; a high pressure side compressor for compressing the refrigerant compressed by the low pressure side compressor; an outdoor heat exchanger for condensing the refrigerant compressed by the high pressure side compressor; a heat recovery unit for cooling the refrigerant condensed in the outdoor heat exchanger by exchanging heat with the refrigerant evaporated in the air conditioner; and a supercooler for expanding a part of the refrigerant cooled in the heat recovery unit to cool another part of the refrigerant cooled in the heat recovery unit, so that the discharge temperature of the low pressure side compressor and/or the high pressure side compressor can be reduced.