Air conditioner
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Solution Overview
Problem
Existing air-conditioning apparatuses face challenges in defrosting outdoor heat exchangers during heating operations, leading to prolonged defrosting times and increased unit size due to the mixing of low-temperature and high-temperature refrigerants, which reduces efficiency and requires additional space for solenoid valves.
Innovation Solution
An air-conditioning apparatus with a switching valve system that allows high-temperature refrigerant from the compressor to be sequentially supplied to parallel flow passages of the outdoor heat exchanger, preventing the mixing of refrigerants and reducing defrosting time, while maintaining a compact unit size by using a single switching valve to switch connection destinations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple solenoid valves are used to switch connection destinations of flow passages during defrosting, then refrigerant mixing is prevented and defrosting efficiency is improved, but the outdoor unit size and installation space increase
Solution Approach 1:
The patent combines the functions of multiple solenoid valves into a single switching valve that can selectively connect different flow passages to either the compressor discharge side or expansion valve outlet. This single valve integrates the defrosting control functionality that previously required multiple separate valves, thereby reducing the outdoor unit size while maintaining defrosting efficiency.
Solution Approach 2:
The switching valve is designed with multiple inlet and outlet ports that can be selectively connected through rotation, allowing a single valve to perform multiple connection configurations. This multi-functional design enables the valve to replace several dedicated solenoid valves, reducing space requirements while maintaining all necessary defrosting and heating operations.
2Ease of operation
If low-temperature refrigerant flows into all flow passages during heating operation, then the system is simple to operate, but refrigerant temperature mixing occurs and defrosting time is prolonged
Solution Approach 1:
The switching valve is designed to be rotatable between multiple angular positions, allowing dynamic reconfiguration of refrigerant flow paths. During heating operation, the valve can be positioned to supply low-temperature refrigerant to specific flow passages requiring defrosting, while during normal operation it distributes refrigerant to all passages. This dynamic adaptability prevents refrigerant mixing issues while maintaining operational flexibility.
3Speed
If high-temperature gas refrigerant is supplied to flow passages for defrosting, then defrosting speed is improved, but refrigerant mixing with low-temperature refrigerant occurs and reduces defrosting efficiency
Solution Approach 1:
The outdoor heat exchanger is divided into multiple parallel flow passages, and the switching valve is configured to supply high-temperature gas refrigerant to specific segments (flow passages) that require defrosting. By segmenting the refrigerant distribution and targeting only the necessary flow passages, the system achieves rapid defrosting without wasteful mixing with low-temperature refrigerant in other passages, thereby improving both defrosting speed and overall 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
The solution enables efficient defrosting of the outdoor heat exchanger during heating operations, reducing defrosting time and preventing the increase in outdoor unit size, thus enhancing operational efficiency and installation space utilization.
Implementation Method 1
high-temperature gas refrigerant discharged from the compressor is caused to flow through a part of the flow passages... heat exchange amount... surface temperature on the outside air side of the outdoor heat exchanger
Implementation Method 2
flow rate of the outside air circulating through the outdoor heat exchanger... heat exchange amount... amount of heat received by the outdoor heat exchanger from the outside air
Implementation Method 3
evaporation temperature of refrigerant flowing through the outdoor heat exchanger... outdoor heat exchanger configured to serve as an evaporator
Implementation Method 4
indoor heat exchanger configured to serve as a condenser
Data Source
Figure 1
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Figure 3
AI summary
Provided is an air-conditioning apparatus including a switching valve and a bypass circuit. The switching valve is provided between an expansion valve and an outdoor heat exchanger. The bypass circuit has a first end connected to a refrigerant pipe connecting a compressor and an indoor heat exchanger to each other, and a second end connected to the switching valve. During a heating operation, the air-conditioning apparatus causes a rotating member of the switching valve to rotate to sequentially connect, to the bypass circuit, flow passages of the outdoor heat exchanger connected in parallel, to thereby defrost the outdoor heat exchanger while performing the heating operation.