Flame Detection System Using Pulsed Voltage and Discharge Counting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional flame detection systems using electron tubes require time for integration to detect flame extinction, making rapid detection difficult, and also involve complex analog signal processing for voltage waveform analysis.
Innovation Solution
A flame detecting system with a pair of electrodes, a pulsed voltage generator, current detector, and a calculating unit that uses stored sensitivity parameters to calculate received light quantity per unit time, allowing for rapid and accurate flame detection without analog signal processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If current integration method is used to detect flame presence, then detection accuracy is improved, but detection speed deteriorates due to required integration time
Solution Approach 1:
The patent applies periodic pulsed voltage to the electron tube electrodes instead of continuous voltage. By periodically applying voltage pulses and counting discharge occurrences during these pulses, the system achieves rapid flame detection without requiring time integration. The periodic action allows the system to determine flame presence based on discharge probability within each pulse period, enabling fast response while maintaining accuracy.
2Speed
If voltage waveform monitoring and analog signal processing are used to detect flame, then detection speed is improved, but device complexity increases
Solution Approach 1:
The patent replaces complex analog signal processing circuits with a simplified digital counting approach. Instead of monitoring continuous voltage waveforms and performing analog signal processing to identify rises and falls, the system uses a counting circuit that simply counts the number of discharge occurrences during voltage pulse periods. This substitution of mechanical/analog processing with a simpler digital counting method reduces device complexity while maintaining fast detection capability.
3Measurement precision
If integration time is extended to improve detection accuracy, then measurement precision is improved, but response time deteriorates
Solution Approach 1:
The patent performs preliminary action by pre-storing sensitivity parameters (reference received light quantity Q0, reference pulse width T0, probability P0 of regular discharge, and probability PN of discharge other than regular discharge) in memory before actual flame detection. During operation, the system quickly compares current discharge counts against these pre-stored parameters to determine flame presence. This preliminary preparation eliminates the need for time-consuming integration during detection, enabling rapid response while maintaining accuracy through pre-calibrated parameters.
Data Source
AI summary
A sensitivity parameter storing portion stores, as known sensitivity parameters owned by a flame sensor, reference received light quantity, reference pulse width, probability of regular discharge, and probabilities of non-regular discharge in advance. The discharge probability is calculated based on the number of drive pulses applied to the flame sensor and the number of discharges determined to have occurred in the flame sensor having received the drive pulses. The calculated discharge probability and the known sensitivity parameters are used to calculate the received light quantity per unit time received by the flame sensor.