Refrigeration Cycle Composition Detection Using Existing Sensor Data
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Solution Overview
Problem
Existing refrigerating and air-conditioning apparatuses using non-azeotropic refrigerant mixtures face challenges in accurately detecting refrigerant composition, leading to reduced heat exchange efficiency, compressor damage, and unstable operation, particularly when multiple expansion processes are involved, increasing costs and development loads.
Innovation Solution
A refrigerating and air-conditioning apparatus that calculates refrigerant composition based on detection results from suction-side and discharge-side pressure, temperature, and rotation speed, using a controller to adjust compressor speed and expansion device opening, thereby improving detection accuracy without increasing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a bypass with double pipe heat exchanger and capillary tube is added to detect refrigerant composition, then refrigerant composition can be detected, but device complexity and cost increase
Solution Approach 1:
The patent extracts the composition detection function from a separate physical detection device and integrates it into the existing controller by utilizing data from already-present sensors (pressure, temperature, rotation speed) and computational algorithms. This eliminates the need for additional detection hardware while maintaining detection capability.
Solution Approach 2:
The controller is given a dual function: it continues to manage the refrigeration cycle while simultaneously performing refrigerant composition detection through computational processing of existing sensor data. This multi-functionality eliminates the need for dedicated detection hardware.
2Measurement precision
If multiple sensors and complex calculation systems are used to improve detection accuracy, then measurement precision improves, but device complexity increases
Solution Approach 1:
The system uses its own existing operational data (from pressure, temperature, and rotation speed sensors already required for normal operation) to perform self-diagnosis and composition detection. No external or additional detection resources are needed.
Solution Approach 2:
The patent transforms the detection approach from direct physical measurement to indirect computational derivation by changing the parameters used for detection from specialized composition sensors to commonly available operational parameters (pressure, temperature, speed) processed through mathematical relationships.
3Device complexity
If refrigerant composition detection is implemented using existing sensors and control systems, then device complexity is reduced, but measurement precision may be compromised
Solution Approach 1:
The patent introduces computational algorithms as an intermediary that bridges the gap between existing operational sensors and refrigerant composition information. The algorithms process readily available sensor data to derive composition metrics that would otherwise require specialized detection equipment.
Data Source
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AI summary
A refrigerating and air-conditioning apparatus 100 or 200, which includes a compressor 2, a condenser 3, an expansion device 4, and an evaporator 5, has a refrigeration cycle configured by these components being connected by a refrigerant pipe, and uses a non-azeotropic refrigerant mixture as a refrigerant circulating through the refrigeration cycle, includes operating state detection means 11 to 14 which detect a pressure of the refrigerant at the compressor 2, a temperature of the refrigerant at the compressor 2, and a rotation speed of the compressor 2, output detection means 15 which detects an output of the compressor 2, and composition detection means 20 which calculates a correlation between the pressure of the refrigerant at the compressor, the temperature of the refrigerant at the compressor, the rotation speed of the compressor 2, the output of the compressor 2, and a refrigerant composition and retains data indicating the correlation. The composition detection means 20 calculates a composition of the refrigerant circulating through the refrigeration cycle, on the basis of detection results of the operating state detection means 11 to 14, a detection result 15 of the output detection means, and the data indicating the correlation.