Segmented Heat Exchanger Flow Paths for Cooling, Heating, and Defrosting
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Solution Overview
Problem
Conventional air conditioners face challenges in efficiently varying the refrigerant passage during both air cooling and air heating operations, as well as effectively performing defrosting operations in heat exchangers.
Innovation Solution
The proposed heat exchanger design includes a compressor that functions as both a condenser and an evaporator, with a configuration of header pipes, heat exchange units, bypass pipes, and valves to control refrigerant flow, allowing for efficient thermal exchange and defrosting by varying the refrigerant passage and using check and expansion valves to manage refrigerant flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional heat exchanger design is used with fixed refrigerant passage, then the structure is simple, but the air conditioner cannot efficiently perform both cooling and heating operations nor effectively defrost
Solution Approach 1:
The heat exchanger is divided into multiple heat exchange units (first, second, third, and fourth units) with separate header pipes (first and second header pipes) that can independently control refrigerant flow paths. This segmentation allows different portions of the heat exchanger to perform different functions simultaneously or sequentially, enabling efficient switching between cooling, heating, and defrosting operations without requiring a complete redesign of the entire system.
Solution Approach 2:
The patent incorporates dynamic flow control mechanisms including a 4-way valve for switching between cooling and heating modes, and a hot gas valve for controlling defrost operations. These valves dynamically redirect refrigerant flow through different header pipes and heat exchange units based on operational requirements, transforming a static heat exchanger into a dynamic system that adapts to various operational modes efficiently.
2Productivity
If the refrigerant passage is varied using multiple valves and pipes, then cooling and heating efficiency is improved, but the device complexity increases
Solution Approach 1:
The first and second header pipes serve multiple functions: they distribute refrigerant to different heat exchange units during cooling mode, redirect refrigerant during heating mode via the 4-way valve, and enable defrost operations through the hot gas valve. This multi-functionality reduces the need for entirely separate pipe systems for each operation mode, thereby improving efficiency while limiting the increase in complexity.
Solution Approach 2:
The hot gas valve acts as an intermediary component that selectively connects the first header pipe to the third heat exchange unit during defrost operations. This intermediary valve allows precise control over hot gas refrigerant flow to specific heat exchange units that require defrosting, without disrupting the overall refrigerant circulation system, thus maintaining efficiency while managing complexity through targeted control.
3Reliability
If frost removal is performed effectively, then heat exchanger performance is maintained, but additional control mechanisms are required
Solution Approach 1:
The defrosting system is designed with local quality by enabling selective defrosting of specific heat exchange units (third and fourth units) through the hot gas valve. Instead of defrosting the entire heat exchanger uniformly, the system can target only the units that require it, achieved by controlling refrigerant flow to specific local regions via the header pipe configuration and valve control, thereby improving defrosting effectiveness while limiting unnecessary system complexity.
Solution Approach 2:
The defrosting operation utilizes the system's own refrigerant as the heat source. By redirecting hot gas refrigerant from the compressor through the hot gas valve to the frosted heat exchange units, the system performs self-defrosting without requiring external heating elements or separate defrosting equipment. This self-service approach enhances reliability by using existing system resources while minimizing additional complexity.
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 design enables efficient operation in both air cooling and heating modes, ensures uniform defrosting of multiple heat exchange units, and facilitates efficient defrosting operations, enhancing the performance of air conditioners in various applications.
Implementation Method 1
a first heat exchange unit coupled to the first header pipe to receive the refrigerant flowing in the first header pipe and to thermally exchange the refrigerant with air in the air cooling operation
Implementation Method 2
a hot gas valve disposed in the hot gas pipe and configured to control a flow of the refrigerant
Implementation Method 3
a check valve disposed in the first header pipe to prevent the refrigerant from flowing from the first header pipe to the second header pipe in the air cooling operation
Implementation Method 4
a compressor to function as a condenser in an air cooling operation and to function as an evaporator in an air heating operation
Data Source
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AI summary
A heat exchanger included in an air conditioner to function as a condenser in an air cooling operation and to function as an evaporator in an air heating operation, the heat exchanger comprising, a first header pipe to have a refrigerant, compressed by a compressor, to flow therein in the air cooling operation; a first heat exchange unit coupled to the first header pipe to receive the refrigerant flowing in the first header pipe and to thermally exchange the refrigerant with air in the air cooling operation; a bypass pipe to have the refrigerant, thermally exchanged in the first heat exchange unit, to flow therein in the air cooling operation; a second header pipe to have the refrigerant, passed through the bypass pipe, to flow therein in the air cooling operation; a second heat exchange unit coupled to the second header pipe to receive the refrigerant flowing in the second header pipe and to thermally exchange the refrigerant with air in the air cooling operation; a hot gas pipe configured to couple the first header pipe and the second header pipe; and a hot gas valve disposed in the hot gas pipe and configured to control a flow of the refrigerant.