Water Heater Scale Detection Using Exhaust Temperature and Clog Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing combustion type water heaters require a dedicated fouling sensor to detect scale buildup in heat exchangers, increasing product size and manufacturing cost, and existing methods for detecting scale buildup are influenced by exhaust pipe clogging, which complicates accurate determination.
Innovation Solution
A combustion type water heater that uses an exhaust gas temperature detector and clog degree detector, without a dedicated sensor, to determine scale buildup by setting an upper limit exhaust gas temperature based on combustion amount and clog degree, and employs normal sensors like current detectors and thermocouples to assess clog levels in the exhaust pipe.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a dedicated fouling sensor is provided to detect scale buildup inside the heat exchanger, then detection accuracy is improved, but product size and manufacturing cost increase
Solution Approach 1:
The system uses existing sensors (exhaust gas temperature detector and clog degree detector) that are already provided for other purposes to detect scale buildup. The controller analyzes exhaust gas temperature changes in combination with clog degree information to determine scale buildup, allowing the system to serve multiple detection functions without adding dedicated sensors.
Solution Approach 2:
The exhaust gas temperature detector and clog degree detector are utilized for dual purposes: their primary functions (temperature monitoring and clog detection) plus the additional function of scale buildup detection. This multi-functional use eliminates the need for dedicated fouling sensors while maintaining detection capability.
2Device complexity
If scale buildup is detected based on exhaust gas temperature alone, then detection simplicity is improved, but determination accuracy deteriorates due to exhaust pipe clogging influence
Solution Approach 1:
The controller receives feedback from both the exhaust gas temperature detector and the clog degree detector, and uses this combined information to accurately determine scale buildup. By monitoring exhaust gas temperature changes in the context of clog degree information, the system can distinguish between temperature changes caused by clogging versus those caused by scale buildup.
Solution Approach 2:
The clog degree information acts as an intermediary that helps interpret exhaust gas temperature data. By considering the clog degree as a mediating factor, the controller can more accurately attribute temperature changes to scale buildup rather than exhaust pipe clogging.
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
Enables accurate detection of scale buildup in the heat exchanger without a dedicated sensor, reducing product size and cost, and promptly detects scale buildup in regions where water easily forms scale, ensuring timely descaling.
Implementation Method 1
a heat exchanger configured to exchange heat between the water passing through on an inside of the heat exchanger and the combustion gas flowing on an outside of the heat exchanger
Implementation Method 2
an exhaust gas temperature detector configured to detect a temperature of the exhaust gas flowing in the exhaust pipe as an exhaust gas temperature
Data Source
AI summary
The present description discloses a combustion type water heater that heats water by burning fuel. The combustion type water heater includes: a burner that generates combustion gas by burning the fuel; a heat exchanger that exchanges heat between the water passing through on an inside of the heat exchanger and the combustion gas flowing on an outside of the heat exchanger, an exhaust pipe that discharges the combustion gas after the heat exchange in the heat exchanger as exhaust gas; an exhaust gas temperature detector that detects a temperature of the exhaust gas flowing in the exhaust pipe as an exhaust gas temperature; a clog degree detector that detects a degree of clog in the exhaust pipe; and a scale buildup determiner that determines whether or not scale has built up inside the heat exchanger based on the exhaust gas temperature and the degree of clog in the exhaust pipe.