Gas Water Heater Exhaust Fan Control Under Wind Pressure
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Solution Overview
Problem
Existing gas water heaters, particularly Q type and G type, face high device costs and operational interruptions due to wind pressure fluctuations, which affect combustion efficiency and user access to the heater.
Innovation Solution
A safety control system for gas water heaters that includes a rotational speed detecting unit, power obtaining unit, and exhaust control unit to adjust the output power of the exhaust fan based on wind pressure conditions, ensuring stable combustion and accurate air volume control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a wind pressure detecting unit is adopted to detect wind pressure and control the exhaust fan, then the combustion operation in case of wind flow backward can be avoided, but the device cost is high and the operation may be interrupted due to slight wind pressure
Solution Approach 1:
The patent extracts the wind pressure detection function from a separate dedicated sensor and integrates it into the existing rotational speed detection mechanism. By reusing the rotational speed detecting unit to infer wind pressure conditions through the relationship between fan rotational speed and exhaust pressure, the system eliminates the need for a separate wind pressure detecting unit, thereby reducing device cost while maintaining combustion safety
Solution Approach 2:
The patent makes the rotational speed detecting unit serve multiple functions: it detects both the rotational speed of the exhaust fan and infers wind pressure conditions at the air outlet. This multi-functionality approach allows the same sensor to provide information for both fan control and safety protection, reducing the overall number of sensors needed in the system
2Reliability
If a wind pressure detecting unit is adopted to detect wind pressure, then combustion safety can be improved, but the operation may be interrupted due to slight wind pressure
Solution Approach 1:
The patent implements dynamic control by continuously monitoring the rotational speed of the exhaust fan and adjusting the output power in real-time based on the detected wind pressure conditions. This dynamic adjustment allows the system to adapt to varying wind pressure conditions without interrupting operation, maintaining both safety and operational continuity
Solution Approach 2:
The patent establishes a feedback control loop where the rotational speed detecting unit continuously monitors fan speed, the control section processes this information to determine wind pressure conditions, and the output power is adjusted accordingly. This closed-loop feedback mechanism enables the system to respond to slight wind pressure changes by adjusting power output rather than interrupting operation
3Device complexity
If the rotational speed of exhaust fan is controlled passively, then the system cost is reduced, but the response speed is slow and control accuracy is limited
Solution Approach 1:
The patent performs preliminary action by proactively adjusting the output power of the exhaust fan based on detected wind pressure conditions before combustion problems occur. The control section calculates the appropriate power adjustment in advance and implements it preemptively, ensuring fast response and maintaining optimal combustion conditions without waiting for problematic situations to develop
Data Source
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AI summary
The present invention provides a gas water heater and a safety control method and system for the same. The system includes: an exhaust fan, configured to exhaust waste gas generated when the gas water heater burns gas; a rotational speed detecting unit, configured to detect a rotational speed of the exhaust fan; a power obtaining unit, configured to obtain a set value for output power of the exhaust fan; and an exhaust control unit, connected to the exhaust fan, the rotational speed detecting unit and the power obtaining unit respectively, configured to determine a wind pressure situation at an air outlet of the exhaust fan according to the rotational speed and the set value for the output power, and to adjust the set value for the output power according to the wind pressure situation. The system may ensure that the gas water heater has a good combustion condition and operates safely and reliably. Moreover, the system has a fast response speed and may provide more accurate air volume, improve the control accuracy and have a low cost.