Refrigerant Piping Layout for Even Heat Exchanger Flow in Heating
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Solution Overview
Problem
In refrigeration apparatuses with multistage compression, uneven refrigerant flow occurs during heating operations due to pressure differences across heat-source-side heat exchangers, leading to inadequate performance as evaporators.
Innovation Solution
The refrigeration apparatus is designed with a multistage compression mechanism and a refrigerant piping group that connects heat-source-side heat exchangers in series during heating operations, ensuring even refrigerant distribution and suppressing uneven flow by routing refrigerant through multiple heat exchangers in a sequential manner.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If heat-source-side heat exchangers are connected in parallel during heating operation, then refrigerant flow distribution becomes uneven due to pressure differences, but connecting them in series increases system complexity
Solution Approach 1:
The patent inverts the conventional parallel connection approach by connecting heat-source-side heat exchangers in series during heating operation. This reversal of the typical configuration eliminates pressure difference-induced flow distribution problems while maintaining system reliability.
Solution Approach 2:
The patent employs dynamic switching mechanisms that change the connection configuration of heat-source-side heat exchangers based on operational mode. During cooling, they connect in parallel; during heating, they connect in series. This dynamic adaptation optimizes performance for each specific operating condition.
2Reliability
If electronic valves or capillary tubes are used to adjust refrigerant flow distribution, then flow uniformity can be improved, but device complexity and manufacturing costs increase
Solution Approach 1:
The patent extracts and eliminates the need for electronic valves and capillary tubes by using a purely structural series connection approach. This removes complex flow adjustment components while achieving the desired flow distribution uniformity through the piping configuration itself.
Solution Approach 2:
The series connection configuration allows the refrigerant flow distribution to self-regulate naturally based on the pressure and flow characteristics of the system, eliminating the need for active control mechanisms or complex adjustment devices.
3Productivity
If heat-source-side heat exchangers are designed to emphasize cooling operation performance, then cooling efficiency improves, but heating operation performance deteriorates due to pressure loss differences
Solution Approach 1:
The patent uses dynamic switching to change the connection mode of heat-source-side heat exchangers based on the operational requirement. During cooling, parallel connection optimizes cooling efficiency; during heating, series connection ensures uniform flow distribution and maintains heating performance.
Solution Approach 2:
The heat-source-side heat exchangers are designed with multi-functionality, serving as both coolers during cooling operation and evaporators during heating operation. The switching mechanism enables them to adapt their configuration to optimize performance for either function as needed.
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 ensures that refrigerant flows evenly across heat-source-side heat exchangers during heating, maintaining optimal performance and reducing production costs by eliminating the need for complex flow adjustment mechanisms.
Implementation Method 1
a plurality of heat-source-side sub heat exchangers configured to, during the cooling operation, function as radiators that cool intermediate-pressure refrigerant in the course of compression
Implementation Method 2
an expansion mechanism configured to, during the cooling operation, depressurize the refrigerant delivered from the heat-source-side main heat exchanger to the usage-side heat exchanger
Implementation Method 3
The heat-source-side main heat exchanger functions as a radiator during the cooling operation, and functions as an evaporator during the heating operation
Data Source
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AI summary
Providing an air-conditioning apparatus (10) in which uneven flow of refrigerant can be easily supressed. The air-conditioning apparatus (10) is provided with a four-stage compressor (20), first to fourth heat exchangers (41-44), an indoor heat exchanger (12), switching mechanisms (31-34), an expansion mechanism (70), and a refrigerant piping group. The first to third heat exchangers (41-43) during the cooling operation, function as radiators cooling intermediate-pressure refrigerant in the course of compression, and during the heating operation function as evaporators. The fourth heat exchanger (44) functions as a radiator during the cooling operation, and during the heating operation functions as an evaporator. The refrigerant piping group is arranged so that during the heating operation the refrigerant flows in series to the first to third heat exchangers (41-43).