Comparison of different materials of heating tubes

- Oct 07, 2020-

Comparison of different materials of heating tubes

The use performance and safety performance of instant electric water heaters mainly depend on the material. At present, the heater materials of instant electric water heaters in the market are generally divided into the following categories:

stainless steel:
Stainless steel sheathed heater: The technology of stainless steel heating tube is earlier, but due to the poor ductility of stainless steel, the heating tube metal sheath and inner liner are made of seam stainless steel tube heaters, which are covered with welds (the more heating tubes, The more welds), the surface load of the heating tube is high, so it is easy to form scale. This kind of congenital defect is inevitable, which seriously affects the heat dissipation of the metal heating body. In the light of the heating time, the heating time is prolonged, and the electricity is consumed. However, the heating wire in the sheathing tube is easy to break in a short time, so that the water is charged to endanger safety. Even if a magnesium rod is added to protect the heating body, due to the volume limitation, it can only alleviate the scaling problem to a certain extent. Therefore, stainless steel heaters are generally made detachable, which can only be cleaned and maintained regularly. At the same time, it causes the problem of poor sealing during disassembly and assembly, and there are hidden safety hazards.

Glass:
Glass conductive film heating tube: It is a better solution to the anti-corrosion function, but the temperature difference between the north and the south is large, and the thermal expansion and contraction will burst, resulting in water leakage, and the heating film is aging quickly, and the annual power is reduced by 20% The above causes high energy consumption and potential safety hazards.

Red copper:
Pure red copper (oxygen-free red copper) heater: red copper has anti-oxidation and strong corrosion resistance, which can not only reduce the harm of scale, but also has much better thermal conductivity than stainless steel. At the same time, the oxygen-free copper material has strong ductility, so the use of seamless pure copper pipes can reduce the number of welds. The potential of copper is much lower than that of impurity elements in the water, and it will not be subject to electric corrosion, which is fundamentally eliminated. Scale harms and improves thermal efficiency. According to the most inspection report of the Electric Hot Water Appliance Laboratory of the China Daily Appliance Quality Supervision and Inspection Center, and the test results related to water appliances by the Chinese Center for Disease Control and Prevention, both show: oxygen-free copper heater In its material selection and design, it is shown that its 100% antibacterial and anti-fungal properties rank first among the tested materials. However, the material cost of oxygen-free copper is 4 times that of stainless steel material. The cost is too high, which has affected its wide application in the instant electric water heater industry use. Therefore, the use of oxygen-free copper in the core components of instant electric water heaters has greatly improved the safety factor of the water heater, and has also become a watershed between high-end and low-end fast electric water heaters.