Renovation of the economizer in the waste heat boiler
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A comprehensive replacement of the economizer in the waste heat boiler was carried out, with the 711th Research Institute of CSSC Corporation responsible for the design and modification. In the modified waste heat boiler, both the high-temperature and low-temperature economizers adopt a modular box structure. Fixed rotary steam soot blowers controlled automatically by PLCs have been installed in these economizers, and an additional hot water preheater has been added to raise the temperature of the deaerated water entering the steam generation system, thereby increasing steam production and achieving energy savings and efficiency improvements. Meanwhile, the Hunan construction team repaired the lining of the waste heat boiler, and the repair was successful. The conditions after replacing the economizer are as follows:Item | Before renovation | After renovation | Comparison notes
Steam generation system inlet temperature °C | 104 | 200 or higher | Increased by nearly 100°C; excellent result
Low-temperature economizer feedwater temperature °C | 104 | 150 | Increased by nearly 50°C; excellent result
Flue gas temperature °C | 320 | 190 (adjustable) | Most of the heat energy is recovered
Flue gas pressure drop KPa | 5 | 3 | The pressure difference has decreased; good result
Waste heat boiler steam output T/h | 15 | 15 | No significant change in waste heat-driven steam production
External heat utilization steam output T/h | 48 | 53 | Increased by 5 T/h
Medium-pressure steam drum steam output T/h | 24 | 28 | Increased by 4 T/h
Benefits after renovation: 9 more tons of steam are produced per hour; at a cost of 130 yuan per ton of steam. Daily benefit: Yuan Monthly benefit: Yuan Annual benefit: Yuan 28080 842400 9266400
Our coal-saving section was also modified by Institute 711, using a modular box structure as well. Construction is about to begin; it’s unclear what the results will be. It’s not known by how much the exhaust temperature will drop from 200°C. This post was last edited by chengkang on 2009-3-7 at 12:25
Our factory also uses the technology from Institute 711; during the renovation, the exhaust temperature was reduced from 220 degrees to around 180 degrees, and the gas production rate increased by 4 t/h.
The benefits of the data-driven improvements are quite good. These days, steam soot blowers are rarely used in excess-heat boilers due to concerns over corrosion; instead, sound waves or shock waves are mostly employed.
We use shock wave soot blowers, which work well; compared to steam soot blowers, there are fewer maintenance requirements. (under the same effect)