Gas heater
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional outdoor gas heaters with thermocouple actuated gas safety shut-offs are prone to shutting off gas supply due to windy conditions, leading to inconvenient and potentially hazardous situations where the flame flickers, causing the thermocouple to generate a micro-current below the threshold, resulting in the solenoid valve closing and shutting off gas.
Innovation Solution
A gas heater design featuring multiple thermocouple devices connected in series, with each thermocouple adjacent to a burner, ensuring that even if one thermocouple does not generate sufficient current, the combined current maintains the solenoid valve in an open position, preventing unnecessary gas shut-off, and includes a wind diffuser to minimize wind impact on the thermocouples.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single thermocouple probe is used for gas safety shut-off, then the device complexity is reduced, but the reliability deteriorates under windy conditions where the flame flickers and the generated current falls below the threshold
Solution Approach 1:
The patent combines multiple thermocouple devices (at least two) to work together in a single gas heater system. Each thermocouple is positioned near a burner and generates electrical current in response to flame heat. The combined current from multiple thermocouples ensures that even if one thermocouple generates insufficient current due to wind-induced flame flickering, the total current remains above the threshold needed to keep the solenoid valve open and maintain gas supply.
2Reliability
If the solenoid valve is highly sensitive to current threshold, then the safety response to flame extinction is improved, but the ease of operation deteriorates due to unnecessary shut-offs during windy conditions
Solution Approach 1:
The patent implements a cushioning effect by using multiple thermocouples in parallel, which provides a buffer against current fluctuations. The combined current generation capacity creates a margin above the threshold value, cushioning the system against temporary drops in current that occur during windy conditions. This prevents the solenoid valve from unnecessarily closing while still maintaining the ability to detect genuine flame extinction events.
3Measurement precision
If the thermocouple is positioned close to the burner for effective heat sensing, then the temperature differential detection is improved, but the object-affected harmful factors worsen due to direct wind exposure on the thermocouple
Solution Approach 1:
The patent positions multiple thermocouples near burners, and the combined signal from these thermocouples compensates for the harmful effect of wind exposure on individual thermocouples. Each thermocouple remains close to its associated burner for effective heat sensing, but the aggregation of signals from multiple thermocouples ensures that wind-induced variations in any single thermocouple's output do not cause false shut-off events.
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 design ensures continuous gas supply to the burners, reducing the risk of fire hazards and inconvenience by maintaining the solenoid valve open even during windy conditions, while shutting off gas when all burners extinguish, thus providing reliable heat and safety.
Implementation Method 1
The thermocouple probes operate according to the 'Seebeck' principle. According to this principle, a micro-current is generated when a temperature differential is present in a closed circuit consisting of wires made of two dissimilar metals.
Implementation Method 2
Such a valve is biased to a closed position for preventing the supply of gas, but the micro-current of the thermocouple, if above a threshold current applicable to the solenoid, can maintain the solenoid valve in an open condition to allow the supply of gas to the heater burner.
Data Source
Figure 1~4
AI summary
A gas heater (10) includes heater burner (16). Heat is generated by the ignition of gas supplied to the burner via conduits (20). A solenoid gas safety valve (22), when provided with a threshold electrical current, is maintained in an open condition allowing passage of gas to the burners. When not provided with that threshold current, the valve is closed, preventing the passage of gas. An electrical current generator (28) includes spaced apart thermocouple devices (30, 32). Due to a combined electrical current generation by the thermocouples, the current generator can generate electrical current at least said threshold current even if any one of the thermocouple devices does not generate the threshold electrical current