Since the successful development of China’s first gas water heater, gas water heaters have become popular in the Chinese market in the short period of more than 30 years due to their instant heat, small size and other advantages. Heat exchangers are the core 'heart' components of gas water heaters. The shuttle passes through here and is rapidly heated to hot water. However, due to the relatively complicated water environment in China, the water quality in some areas contains relatively high concentrations of sulfate and chloride ions, which may interact with traditional copper heat exchangers. Corrosion reaction often causes water leakage and threatens safety.
Stainless steel heat exchanger is more suitable for Chinese market demand
Due to the complexity of China's water quality environment, only 'strongly corrosive' materials are more suitable for the Chinese market. However, there are also some manufacturers who try to achieve 'delayed corrosion' by thickening the thickness of copper heat exchangers. Solve the heat exchanger corrosion problem.
After many years of exploration, the industry has finally broken the deadlock until stainless steel materials are successfully used in heat exchanger manufacturing. As its name implies, stainless steel material has a 'stainless' quality, its excellent corrosion resistance can withstand air, steam, condensation The corrosion of water and other acidic substances is the key to solving the corrosion problem of gas water heater water. Taking an AO Smith gas water heater equipped with a commercial-grade stainless steel heat exchanger as an example, the experiment shows that the concentration of simulated chloride ions exceeds 40000-60000 ppm in a severely exceeded standard. In the 2000ppm water quality, the corrosion resistance of the AO Smith commercial grade stainless steel heat exchanger is about 3.9 times that of the copper heat exchanger.
Overcoming industrial challenges, stainless steel heat exchangers achieve high heat exchange efficiency
The poor thermal conductivity of stainless steel, only to re-design the structure of stainless steel heat exchanger, increase the heat transfer area, can improve the heat transfer efficiency.
For example, the number of normal copper heat exchanger water pipes is usually 6; however, the number of water pipes in stainless steel heat exchangers has increased to 15 and the heat transfer area has increased by 2.5 times. It is like that 6 copper pots can be used to boil water. You can use 15 stainless steel pots to boil water, so that even if the copper pan boiled water, there are many stainless steel pots, so that the stainless steel heat exchanger water production can be comparable with the traditional copper heat exchanger.
The China Household Electrical Appliances Research Institute conducted an authoritative evaluation of A.O. Smith's commercial grade stainless steel heat exchangers. The results show that the heat exchange efficiency can be as high as 90% or more, reaching the national secondary energy efficiency standard.
However, it is not easy to increase the stainless steel heat exchanger area by a factor of 2.5. This is because stainless steel has a high melting point and poor ductility, which makes its forging process extremely difficult. Even AO Smith, the pioneer of open air, is constantly experimenting. , trial and error, has paid a huge R & D, process and manufacturing costs, and finally forged this 'steel heart'. More than this, AO Smith also promised that its commercial grade stainless steel heat exchanger enjoy 5 years replacement, which shows that Excellent product quality.
In the case where the heat exchange efficiency and the forging process are successfully solved, the gas water heater equipped with a commercial-grade stainless steel heat exchanger is clearly more suitable for the consumption trend of the Chinese gas water heater market represented by AO Smith, and its performance in antisepsis and anti-fouling Even better, once it was introduced, it was favored by many consumers. It is a landmark replacement in the history of the gas water heater industry.