Refrigerant Composition Detection Using Compressor Operating 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 increased costs due to complex detection methods and high component costs.
Innovation Solution
A refrigerating and air-conditioning apparatus with operating state detection means, output detection means, and composition detection means that calculates refrigerant composition based on operating state and output data, reducing the need for costly components and complex detection systems.
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 measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent extracts the composition detection function from a complex physical detection system and implements it through calculation using readily available operating parameters (suction pressure, suction temperature, discharge pressure, rotation speed, output). This eliminates the need for additional detection hardware while achieving accurate composition measurement through mathematical correlation.
Solution Approach 2:
The patent replaces the mechanical/physical detection system (double pipe heat exchanger, capillary tube, temperature sensors, pressure sensors) with a computational approach. The composition detection means calculates refrigerant composition based on operating state parameters and output data, substituting physical detection infrastructure with information processing.
2Measurement precision
If liquid level detector is installed in accumulator to detect refrigerant composition, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent enables the existing compressor and control system to perform composition detection functions using their own operating data (pressure, temperature, rotation speed, output) without requiring external detection devices. The system uses its inherent operational information to calculate composition, making the detection capability self-generated rather than externally imposed.
Solution Approach 2:
The operating state detection means and output detection means serve dual purposes: they monitor compressor performance for control purposes and simultaneously provide data for refrigerant composition calculation. This multi-functionality eliminates the need for dedicated composition detection hardware.
3Measurement precision
If multiple temperature and pressure sensors are installed to detect refrigerant composition, then measurement precision is improved, but manufacturing cost increases
Solution Approach 1:
The patent creates a virtual model of refrigerant composition by calculating it from correlated operating parameters rather than physically measuring it. The composition detection means uses mathematical relationships to generate composition information based on copies of existing operational data, avoiding the cost of additional physical sensors.
Solution Approach 2:
The patent transforms the approach from directly measuring composition parameters to inferring composition from readily available operating parameters (pressure, temperature, speed, power). By changing the detection parameters from direct composition measurement to indirect inference through calculation, the system reduces hardware costs while maintaining measurement capability.
Data Source
AI summary
A refrigerating and air-conditioning apparatus, which includes a compressor, a condenser, an expansion device, and an evaporator, 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 which detect a pressure of the refrigerant at the compressor, a temperature of the refrigerant at the compressor, and a rotation speed of the compressor, output detection means which detects an output of the compressor, and composition detection means 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, the output of the compressor, and a refrigerant composition and retains data indicating the correlation.