What are the disadvantages of traditional hot water boilers?

Answer: At present, most of the boilers of heating and hot water in China are traditional hot water boilers (atmospheric pressure or pressure hot water boilers), but often have a short service life, and some are scrapped in three or five years, the reason is not the boiler itself manufacturing quality problems, but there is inevitable corrosion and scaling in the use process: ① During the construction and deactivation of traditional boilers, air will invade the pot due to the lack of protective measures. Because of the oxygen and moisture in the atmosphere. This results in oxygen corrosion. And the pit caused by oxygen corrosion will accelerate the corrosion in the later operation process; During the entire system shutdown. Especially where it is easy to put water, if there is residue and water slag on the surface, the corrosion will be more serious than normal work. B. Condensation corrosion of return water: The heating cycle return water temperature in the northern region is designed to be 75 ° C, but the actual use is often 50 ° C or lower. At this time, the water vapor in the flue gas condenses into liquid water, and mixes with SO2, NOX and other substances produced by combustion, forming strong acids to seriously corrode the chimney, smoke chamber and smoke pipe, and the red rust water flowing out of the boiler smoke chamber is corroded. Even imported boilers have this corrosion, and serious boilers will rot in about three years. 3. Furnace body, smoke pipe scaling: many hot water boilers are directly heated by external hot water, and the quality of water directly affects the service life of the boiler. With the heating of hot water, the scale will continue to precipitate and be deposited on the furnace and smoke pipe, which will cause the increase of heat transfer resistance and the reduction of boiler efficiency. When the scale accumulates to a certain extent, the furnace will burn, the smoke pipe will break, and the boiler will be scrapped.

The selection of atmospheric boiler should consider the economy of the system configuration. Ordinary atmospheric boiler is suitable for low-rise or multi-storey buildings, large buildings with large heat load, small boilers need to use multiple atmospheric hot water boilers, low efficiency, it is recommended not to use.

When selecting a boiler, its rated thermal efficiency should comply with the provisions of GB50189-2005 "Energy-saving Design Standards for public Buildings" on the rated thermal efficiency of oil and gas steam hot water boilers ≥89%.

In order to avoid evaporation, from the perspective of safety, the design outlet temperature of low-temperature pressurized hot water boiler is 95 degrees, the return water temperature is 70 degrees, the design outlet temperature of atmospheric pressure hot water boiler is 85 degrees, the return water temperature is 60 degrees.