Compressor return gas dryness detection method, apparatus, device, and storage medium
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Solution Overview
Problem
The high adiabatic coefficient of R32 refrigerant leads to elevated exhaust gas temperatures in air conditioning systems, causing potential compressor damage due to refrigerant oil dilution and abnormal wear, which existing technologies fail to address effectively without increasing hardware costs.
Innovation Solution
A compressor return gas dryness detection method that calculates the return gas dryness based on exhaust gas pressure, return gas pressure, working frequency, and exhaust gas temperature, using temperature difference values and enthalpy calculations to determine the dryness and adjust compressor operation accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If liquid-carrying return gas technology is used to lower exhaust gas temperature, then exhaust gas temperature is reduced, but return gas dryness cannot be measured leading to compressor reliability issues
Solution Approach 1:
The patent replaces physical measurement devices (such as direct dryness sensors or additional hardware) with a calculation-based approach. By substituting mechanical measurement systems with thermodynamic calculations using readily available parameters (pressures, temperatures, frequency), the system achieves dryness detection without increasing hardware complexity, thereby maintaining compressor reliability while using liquid-carrying return gas technology.
Solution Approach 2:
The patent introduces an intermediary calculation model that uses easily measurable parameters (exhaust gas pressure, return gas pressure, working frequency, exhaust gas temperature) as mediators to infer the difficult-to-measure return gas dryness. This intermediary approach allows indirect detection of dryness without direct contact with the refrigerant flow, solving the measurement problem while maintaining system reliability.
2Device complexity
If return gas dryness is not measured, then hardware cost is reduced, but compressor refrigerant oil dilution and abnormal wear occur
Solution Approach 1:
The patent replaces complex mechanical measurement systems with a calculation-based approach. By substituting physical dryness sensors with thermodynamic calculations using readily available parameters (pressures, temperatures, frequency), the system achieves dryness detection without increasing hardware complexity, thereby maintaining compressor reliability while avoiding refrigerant oil dilution and abnormal wear.
Solution Approach 2:
The patent enables the system to self-diagnose return gas dryness using existing sensors and built-in computational capabilities. The controller utilizes data already being collected for other control functions (pressures, temperatures, frequency) and applies thermodynamic calculations to determine dryness, allowing the system to monitor its own state without additional measurement hardware.
3Object-affected harmful factors
If R32 refrigerant is used instead of R410a, then environmental friendliness is improved, but exhaust gas temperature increases causing compressor damage
Solution Approach 1:
The patent changes the operating parameters of the R32 system by implementing liquid-carrying return gas technology, which modifies the thermodynamic state of the refrigerant entering the compressor. This parameter change (introducing liquid carryover) effectively lowers the exhaust gas temperature to acceptable levels while maintaining the environmental benefits of R32 refrigerant.
Solution Approach 2:
The patent implements a feedback control mechanism where the controller continuously monitors exhaust gas temperature and return gas dryness (calculated from pressure and temperature data). When exhaust gas temperature exceeds the threshold or dryness becomes too low, the system adjusts operating parameters to maintain safe compressor operation, enabling continuous use of R32 refrigerant without damage risks.
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
Accurately calculates the return gas dryness, preventing compressor damage by controlling the dryness within a predetermined interval, thus enhancing compressor reliability and extending its operational lifespan.
Implementation Method 1
determining an exhaust gas enthalpy value based on the exhaust gas pressure and the exhaust gas temperature; calculating a compression ratio based on the exhaust gas pressure and the return gas pressure, and determining a theoretical enthalpy difference based on the compression ratio; determining an absolute thermal efficiency of the compressor based on the exhaust gas pressure, the return gas pressure, and the working frequency; and calculating the return gas dryness of the compressor based on the exhaust gas enthalpy value, the theoretical enthalpy difference, the absolute thermal efficiency of the compressor, and the return gas pressure
Data Source
AI summary
A compressor return gas dryness detection method includes: obtaining an exhaust gas pressure, a return gas pressure, a working frequency, an exhaust gas temperature, and a return gas temperature of a compressor; determining a return gas saturation temperature corresponding to the return gas pressure; calculating a temperature difference value based on the return gas temperature and the return gas saturation temperature; and in accordance with a determination that the temperature difference value is smaller than a predetermined threshold value, calculating a return gas dryness of the compressor based on the exhaust gas pressure, the return gas pressure, the working frequency, and the exhaust gas temperature.