Refrigerant Charge Detection Using Condenser Liquid Phase Ratio
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Solution Overview
Problem
Existing air conditioner refrigerant filling technologies struggle to accurately judge the refrigerant amount, especially during heating operations and when multiple condensing heat exchangers are present, and require manual input of pipe lengths, which can be impractical and error-prone, especially when pipes are buried. Additionally, they fail to account for the presence of liquid refrigerant in accumulators and require labor-intensive processes to determine the correct refrigerant amount.
Innovation Solution
The system calculates a condenser liquid phase area ratio based on multiple parameters, including refrigerant condensation temperature, super-cooling degree, intake fluid temperature, enthalpy difference, and liquid specific heat, to accurately judge the refrigerant filling state, allowing for automated filling and accounting for various condenser capacities and configurations, including those with accumulators.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If manual input of pipe lengths is required to judge refrigerant filling amount, then the judgment can be based on installation parameters, but the process becomes labor-intensive and error-prone when pipes are buried
Solution Approach 1:
The system automatically detects refrigerant filling amount using sensors and control units without requiring manual pipe length measurement. The controller judges the filling state by automatically acquiring operation parameters like superheating degree and supercooling degree, eliminating the need for manual input and reducing errors from buried pipes.
Solution Approach 2:
The patent replaces manual measurement methods with automated sensor-based detection. Instead of physically measuring pipe lengths, the system uses temperature and pressure sensors to detect operation parameters and calculates refrigerant filling amount through electronic control, substituting mechanical measurement with automated sensing.
2Device complexity
If existing refrigerant filling methods use single condensing heat exchanger models, then the system design is simplified, but the methods fail to accurately judge refrigerant amount when multiple condensing heat exchangers or heating operations are involved
Solution Approach 1:
The controller is designed to handle multiple operation modes including cooling with single condensing heat exchanger, cooling with multiple condensing heat exchangers, and heating operations. The system universally applies the same detection methodology across all configurations by identifying which heat exchanger is currently functioning as the condensing heat exchanger and using its parameters for judgment.
Solution Approach 2:
The system dynamically adapts to different operational configurations by identifying the active condensing heat exchanger in real-time. When multiple condensing heat exchangers are present or during heating operations, the controller determines which heat exchanger is currently condensing refrigerant and uses that specific heat exchanger's parameters for accurate refrigerant filling judgment.
3Extent of automation
If cycle simulation is implemented from temperature and pressure information, then automated detection is possible, but the method fails when accumulators or receivers are present as they mask temperature and pressure changes
Solution Approach 1:
The patent extracts the detection target from the accumulator or receiver by focusing on the condensing heat exchanger's parameters instead. By measuring superheating degree at the evaporator outlet or supercooling degree at the condensing heat exchanger outlet, the system bypasses the masking effect of accumulators and receivers that hide temperature and pressure changes in the refrigerant cycle.
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 enables stable and accurate refrigerant filling judgments regardless of environmental conditions, automates the filling process, and eliminates the need for manual pipe length input, ensuring accurate refrigerant amounts across different air conditioner configurations and operations.
Implementation Method 1
outlet super-cooling degree of a liquid receiver
Implementation Method 2
heat exchange between the refrigerant within the high pressure-side heat exchanger and the fluid
Data Source
AI summary
An air conditioner is arranged so as to be able to accurately judge a refrigerant filling state within the air conditioner regardless of environmental and installation conditions. The air conditioner has a computing section 102 for computing a condenser liquid phase area ratio that is a value related to an amount of liquid phase portion of the refrigerant within a high pressure-side heat exchanger, based on refrigerant condensation temperature of the high pressure-side heat exchanger, outlet super-cooling degree of the high pressure-side heat exchanger, intake air temperature of the high pressure-side heat exchanger, a difference of enthalpy of inlet and outlet of the high pressure-side heat exchanger and specific heat at constant pressure of a refrigerant solution at the outlet of the high pressure-side heat exchanger and a judging section 106 for judging the refrigerant filling state within the air conditioner based on a comparison of the value computed by the computing section 102 with a predetermined value.