Compressor Bypass Cooling Control for High-Discharge Air Conditioners
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional air-conditioning apparatuses are unable to effectively reduce the increase in compressor discharge temperature, especially when using refrigerants that easily elevate this temperature.
Innovation Solution
An air-conditioning apparatus that adjusts the opening degree of a first flow control device based on discharge temperature measurements, utilizing an auxiliary heat exchanger to cool refrigerant and oil before it returns to the compressor, thereby reducing the compressor's discharge temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If refrigerant that easily increases discharge temperature is used, then cooling capacity is improved, but compressor discharge temperature increases excessively
Solution Approach 1:
The patent applies preliminary action by cooling the refrigerant and oil in the auxiliary heat exchanger before they return to the compressor. This pre-cooling prevents the refrigerant from entering the compressor at high temperature, thereby reducing the discharge temperature while maintaining the use of refrigerants with high cooling capacity
Solution Approach 2:
The auxiliary heat exchanger serves as an intermediary device between the refrigerant circuit and the compressor. It mediates the temperature of the refrigerant and oil before they enter the compressor, allowing the system to use refrigerants that would otherwise cause excessive discharge temperatures while protecting the compressor
2Productivity
If compressor rotational speed is increased to enhance cooling capacity, then cooling performance is improved, but discharge temperature increases and oil degradation accelerates
Solution Approach 1:
The patent uses feedback control by monitoring the discharge temperature with a sensor and adjusting the opening degree of the flow control device accordingly. This feedback mechanism allows the system to maintain optimal discharge temperature even when compressor rotational speed is increased, preventing oil degradation while preserving high cooling capacity
Solution Approach 2:
The patent applies dynamics by making the flow control device adjustable based on operating conditions. The opening degree is dynamically changed according to the discharge temperature, allowing the system to adapt to varying compressor speeds and maintain reliable operation while maximizing cooling capacity
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 approach effectively decreases the compressor's discharge temperature, reducing oil degradation and the risk of compressor damage, while also enhancing cooling capacity and user comfort by allowing for increased compressor rotational speed.
Implementation Method 1
utilizing an auxiliary heat exchanger to cool refrigerant and oil before it returns to the compressor
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
An air-conditioning apparatus includes a refrigerant circuit in which pipes sequentially connect a compressor, a flow switching device, a heat source side heat exchanger, an expansion device, a load side heat exchanger, and the flow switching device, and configured to perform a cooling operation and a heating operation switched by the flow switching device, an oil separator configured to separate refrigerating machine oil from refrigerant discharged from the compressor, a first bypass passage in which fluid flowing out of the oil separator flows, an auxiliary heat exchanger configured to cool the fluid, a first flow control device configured to control passing of the fluid, a second bypass passage in which liquid refrigerant or two-phase gas-liquid refrigerant flowing through one of the pipes connecting the heat source side heat exchanger and the expansion device flows, and a second flow control device configured to control passing of refrigerant.