Research of Gas Water Heater Cycling System The laboratory Immersion Corrosion Test of Metal
Abstract
This study is based on the experimental method to investigate the gas water heater cycling piping system, In this experiment, the accelerated corrosion rate of laboratory immersion corrosion test of metal and electrochemical methods, three kinds of water quality to pure water, tap water, groundwater as a corrosion observed. Flow field experiments rectangular boxes, copper tube and acrylic sheet components, In order to visualize the flow, the shadowgraph technique is used. In order to understand the structure of the flow field and flow field of temperature and concentration measurement analysis and mass transfer rates.
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Introduction
The existing water heaters are actually a type of energy conversion device, which converts electric energy, the chemical energy of fuel, or solar energy into heat energy, and uses the high heat capacity of water to contact the heat source indirectly to carry the heat away. In addition, this type of heat absorber (sink) requires an additional container for storing water by the host, the contour design of this container shall have sufficient heat absorption (sinking) capability to increase or reduce the water temperature, and this design using medium with high heat capacity to absorb (eliminate) heat usually causes heat flow fouling on the contact surface of any two objects. This contact thermal resistance has been discussed in depth in literature. For example, Kenneth W. B. et al. [1], Miroslav Colic et al. [2], R. L. D. Caneet al. and [3]. Li et al. [4] collected 679 water quality samples, and analyzed the LSI value to judge the trend of scale or corrosion. This study discusses the causes of corrosion in the water heater circulation system, the factors influencing pitting corrosion, and the countermeasures against corrosion, and the scale formation in the circulating water tower system and the work flow of the descaling device are evaluated and analyzed.
[5]Corrosion potential would be predicted correctly by chosen exact indicator. LSI is used generally for the indicator of corrosion potential. Database of this study were collected from the city water website. Including temperature, hardness, alkalinity, pH, the sulfate etc. The saturation indices can be predicted by using the MINEQL+ model for the reference city water. The result of this study indicted that, Taipei city water has a negative LSI value and corrosive tendency. Hsinchu city water has a positive LSI value and precipitating tendency.
Conclusion
1. The design of the pipeline exhaust at high temperature can remove the water vapor pressure inside the thermal circulation pipeline, clear the flow path, and is corrosion resistant.
2. According to the experimental observations of the flow field, the metal pitting corrosion potential decreases as the medium temperature rises, the pitting corrosion is accelerated, and according to the concentration distribution and flow pattern, there shall be uniform corrosion in the copper tube.