Flame Detection System Noise Removal via Shutter Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing flame detection systems face challenges in accurately distinguishing regular discharges from irregular noise components, leading to erroneous flame detection due to the presence of noise components like thermal electrons, inrush current, and residual ions.
Innovation Solution
A flame detection system that calculates the received light quantity by periodically applying a drive pulse voltage to an optical sensor, differentiating between regular and irregular discharges using a shutter mechanism to switch between light-shielded and light-receiving states, and employing sensitivity parameters to determine the presence or absence of a flame.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a photoelectric tube-type ultraviolet sensor is used to detect flame, then flame detection capability is provided, but irregular discharge phenomenon (pseudo discharge) occurs due to noise components causing erroneous detection
Solution Approach 1:
The patent segments the discharge phenomenon into two distinct components: regular discharge (caused by ultraviolet light from flame) and irregular discharge (noise components). By measuring and subtracting the irregular discharge component separately, the system isolates the true flame signal, resolving the contradiction between detection capability and noise interference.
Solution Approach 2:
The patent extracts and measures the irregular discharge component as a separate quantity from the total discharge. By calculating the irregular discharge probability and using it to subtract the noise component from the total received light quantity, the system removes the harmful noise while preserving the useful flame detection signal.
2Measurement precision
If the discharge probability of noise component is considered to obtain received light quantity, then accurate flame detection is enabled, but the discharge probability needs to be known in advance which is not easy to derive
Solution Approach 1:
The patent enables the system to self-determine the irregular discharge probability by measuring it directly during operation using the shutter mechanism. Instead of requiring pre-known parameters from external sources, the system autonomously characterizes its own noise properties, simplifying the overall process while maintaining measurement precision.
Solution Approach 2:
The patent performs preliminary measurement of the irregular discharge probability by blocking light with a shutter before actual flame detection. This preliminary action characterizes the noise baseline, which is then used to accurately calculate the received light quantity during subsequent detection operations.
3Reliability
If a shutter mechanism is provided to block electromagnetic wave to detect failure, then self discharge detection is enabled, but there is no method of distinguishing regular discharge from irregular discharge
Solution Approach 1:
The patent segments the discharge measurement into two distinct phases: irregular discharge measurement (with shutter closed, blocking light) and regular discharge measurement (with shutter open, allowing light). This temporal and conditional segmentation enables clear differentiation between noise components and true flame signals, resolving the detection difficulty.
Solution Approach 2:
The patent uses feedback by comparing the discharge characteristics measured with the shutter closed (irregular discharge only) against the total discharge measured with the shutter open. This feedback mechanism enables the system to distinguish and separate regular from irregular discharge, accurately determining sensor status and flame presence.
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
This approach allows for accurate detection of the presence or absence of a flame by removing noise components from the received light quantity, reducing the likelihood of erroneous sensor life determination and improving detection accuracy.
Implementation Method 1
an optical sensor configured to detect light emitted from a light source
Data Source
AI summary
A flame detection system includes: an optical sensor that detects light generated from a light source; an applied voltage generating circuit that periodically applies a drive pulse voltage to the optical sensor, discharge determining portion that detects a discharge from the optical sensor, a discharge probability calculating portion that calculates a discharge probability based on a number of times of application of the drive pulse voltage and a number of times of discharge detected in the a first state in which the optical sensor is shielded from light and a second state in which the optical sensor can receive light, a sensitivity parameter storing portion storing known sensitivity parameters of the optical sensor; and a received light quantity calculating portion that calculates the received light quantity by the optical sensor in the second state based on the sensitivity parameters and the discharge probabilities calculated in the first and second states.