Refrigeration Cycle Bypass Cooling Without Heat Exchanger Capacity Loss
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Solution Overview
Problem
The refrigeration cycle apparatus experiences a decrease in heating and cooling capacity due to refrigerant being bypassed from the high-pressure side, reducing the flow rate in heat-source-side and load-side heat exchangers.
Innovation Solution
The bypass pipe extends from the liquid pipe between the first and second expansion devices to the suction side of the compressor, ensuring refrigerant discharged from the compressor flows directly to the heat-source-side or load-side heat exchanger without bypassing, thus maintaining full capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If refrigerant is bypassed from the high-pressure side to cool the controller, then the controller cooling function is improved, but the heating and cooling capacity of the refrigeration cycle apparatus is reduced
Solution Approach 1:
The refrigerant circuit is divided into a main circuit and a branch circuit. The main circuit ensures full refrigerant flow through heat exchangers for heating/cooling capacity, while the branch circuit selectively bypasses a portion of refrigerant to cool the controller. This segmentation allows both functions to operate simultaneously without compromising overall capacity.
2Ease of operation
If refrigerant flow rate through heat exchangers is reduced by bypassing, then controller cooling is achieved, but heat exchange efficiency deteriorates
Solution Approach 1:
The bypass valve is designed with variable opening degree that can be dynamically adjusted based on operating conditions. The control device monitors system parameters and adjusts the bypass valve opening to optimize the balance between controller cooling and heat exchanger performance, ensuring dynamic adaptation to different load conditions.
3Temperature
If bypass pipe is configured to extract refrigerant early in the high-pressure side, then controller cooling effectiveness is improved, but refrigerant flow to heat exchangers is significantly reduced
Solution Approach 1:
The bypass pipe is strategically positioned to extract refrigerant from a specific location on the high-pressure side that provides sufficient pressure for controller cooling while minimizing impact on overall system flow. The local refrigerant properties at this extraction point are optimized to provide effective cooling without significantly reducing the quantity of refrigerant available for heat exchange in the main circuit.
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 prevents capacity loss and enhances heating and cooling performance by ensuring all refrigerant contributes to heating and cooling, improving the overall efficiency of the refrigeration cycle.
Implementation Method 1
the refrigerant is made to flow to a refrigerant cooler and is made to exchange heat with a controller, thereby cooling the controller
Implementation Method 2
passes through an expansion device for controlling the flow rate of the refrigerant in the refrigerant cooler
Data Source
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AI summary
A refrigeration cycle apparatus includes: a refrigerant circuit in which a compressor, a heat-source-side heat exchanger, a first expansion device, a second expansion device, and a load-side heat exchanger are sequentially connected by refrigerant pipes and in which refrigerant is circulated; a controller that controls the refrigerant circuit; a bypass pipe extending from a liquid pipe between the first expansion device and the second expansion device toward a suction side of the compressor; a third expansion device provided at the bypass pipe to decompress the refrigerant that flows through the bypass pipe; and a refrigerant cooler provided at the bypass pipe and downstream of the third expansion device to cause heat exchange to be performed between the refrigerant decompressed by the third expansion device and heat generated from the controller.