Virtual Superheat Measurement Sensor for Refrigeration Cycle
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Solution Overview
Problem
Existing air-conditioning and heat pump systems face challenges in determining the refrigerant charge level without invasive pressure measurements, which can lead to reduced efficiency, compressor damage, and environmental issues due to refrigerant leakage.
Innovation Solution
A virtual superheat measurement (VSM) system that uses non-invasive temperature measurements to calculate the refrigerant charge level and compressor efficiency, eliminating the need for pressure sensors and allowing for remote monitoring without breaching the sealed system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If pressure measurements are used to determine refrigerant charge level, then measurement precision is improved, but the system reliability deteriorates due to potential refrigerant leakage and unsafe operating conditions
Solution Approach 1:
The patent replaces mechanical pressure sensors that require breaching the sealed system with a virtual sensing approach using temperature measurements and thermodynamic calculations. This substitution eliminates the need for physical access to the refrigerant, maintaining system integrity while achieving accurate charge level determination through non-invasive temperature-based virtual sensors.
Solution Approach 2:
The patent introduces temperature measurements as an intermediary parameter to indirectly determine refrigerant charge level without direct pressure measurement. By using temperature data from accessible locations combined with thermodynamic models, the system mediates between the need for accurate charge level information and the requirement to maintain system sealing and safety.
2Measurement precision
If pressure sensors are installed to measure refrigerant charge level, then measurement precision is improved, but device complexity increases due to system breaching and additional components
Solution Approach 1:
The patent replaces complex mechanical pressure sensing systems with a computational approach using temperature measurements and thermodynamic calculations. This substitution simplifies the physical system by eliminating pressure sensors, service ports, and associated hardware while maintaining measurement accuracy through virtual sensing algorithms.
Solution Approach 2:
The patent creates virtual copies of pressure measurement functionality through temperature-based calculations. Instead of physically measuring pressure, the system calculates equivalent pressure information from temperature data using thermodynamic relationships, effectively copying the measurement function without the physical complexity.
3Measurement precision
If technician presence is required for pressure measurements, then measurement precision is improved, but productivity decreases due to time delays and service costs
Solution Approach 1:
The patent enables the system to self-diagnose refrigerant charge level using temperature measurements and built-in thermodynamic calculations. This self-service capability eliminates the need for technician intervention for routine charge level checks, allowing continuous monitoring and automatic detection of charge issues without service calls or manual measurements.
Solution Approach 2:
The patent implements continuous temperature monitoring with feedback to determine refrigerant charge level in real-time. This feedback mechanism provides ongoing measurement capability without requiring periodic technician visits, enabling proactive maintenance and improving service productivity by reducing routine intervention needs.
4Measurement precision
If the sealed air-conditioning system is breached for pressure measurement, then measurement precision is improved, but loss of substance occurs due to refrigerant leakage
Solution Approach 1:
The patent replaces mechanical pressure measurement systems that require system breaching with a non-invasive temperature-based virtual sensing approach. This substitution completely prevents refrigerant loss during measurement by eliminating the need to open service ports or breach the sealed system, ensuring refrigerant conservation while maintaining measurement accuracy.
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
Enables accurate determination of refrigerant charge level and system performance without invasive measurements, reducing costs and environmental impact while ensuring safe and efficient operation.
Implementation Method 1
providing at least one temperature sensor configured to measure a suction temperature, a discharge temperature, and a condensing temperature in a cooling mode; and a suction temperature, discharge temperature, and evaporating temperature in a heating mode
Data Source
AI summary
A method for determining superheat for an air-conditioning system or a heat pump system using a virtual superheat measurement system. The method includes a obtaining a compressor efficiency; acquiring concurrent noninvasive measurements of a suction, a discharge, and a condensing temperature; determining a discharge pressure as a saturated pressure corresponding to the condensing temperature; determining a first discharge enthalpy and a discharge entropy as functions of the discharge temperature and the calculated discharge pressure; for all possible values of suction pressure: guessing the suction pressure; determining a suction enthalpy and a suction entropy as functions of guessed suction pressure and suction temperature; determining a second discharge enthalpy as a function of the discharge pressure and the calculated suction entropy; and determining a second compressor efficiency as the difference between the second discharge enthalpy and the suction enthalpy divided by the difference between the first discharge enthalpy and the suction enthalpy.