Defrosting apparatus with low-loss load detection and methods of operation thereof
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Solution Overview
Problem
Conventional capacitive food defrosting systems face inefficiencies when dealing with low-loss dielectric materials, as they primarily dissipate electromagnetic energy as heat, leading to unwanted heating of circuitry.
Innovation Solution
A thermal increase system using RF energy that includes a variable impedance network and power detection circuitry to identify low-loss loads by analyzing RF power values and adjusting signal parameters, allowing for impedance matching and power modification to prevent excessive heat dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional capacitive defrosting systems use electromagnetic energy to thaw food loads, then the food load is warmed gently, but low-loss dielectric materials cause energy to be dissipated as heat in the circuitry rather than being absorbed by the load
Solution Approach 1:
The system performs preliminary detection of load characteristics before initiating full defrosting operation. By measuring RF power values and determining if the load is a low-loss load in advance, the system can adjust signal parameters beforehand to prevent energy dissipation issues, rather than reacting after the problem occurs
Solution Approach 2:
The system continuously monitors RF power values during operation and uses this feedback to detect low-loss load conditions. Based on the detected condition, the controller automatically adjusts signal parameters to optimize energy absorption and minimize circuitry heating, creating a closed-loop control system that adapts to load characteristics
2Productivity
If the system increases RF power to improve defrosting efficiency, then defrosting speed increases, but unwanted heating of circuitry increases when low-loss loads are present
Solution Approach 1:
The system dynamically changes RF signal parameters such as frequency, power level, or pulse duration based on detected load characteristics. When a low-loss load is detected, the controller adjusts these parameters to maintain effective defrosting while preventing excessive energy dissipation and circuitry heating
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
Effectively detects and adjusts for low-loss loads, reducing unwanted heating of system components and ensuring efficient defrosting by minimizing energy dissipation through circuitry.
Implementation Method 1
a radio frequency (RF) signal source configured to supply an RF signal to an electrode to cause the electrode to radiate RF electromagnetic energy
Data Source
Figure 1A~1B
Figure 2A
Figure 2B
AI summary
A system includes a radio frequency (RF) signal source configured to supply an RF signal. An electrode is coupled to the RF signal source and a transmission path is between the RF signal source and the electrode. The transmission path is configured to convey the RF signal from the RF signal source to the electrode to cause the electrode to radiate RF electromagnetic energy into a cavity. Power detection circuitry is coupled to the transmission path and configured to repeatedly measure RF power values including at least one of forward RF power values and reflected RF power values along the transmission path. A controller is configured to determine that a load in the cavity is a low-loss load based on a rate of change of the RF power values, and cause the RF signal source to supply the RF signal with the one or more desired signal parameters.