As an air preheating device widely used in power station boilers and industrial boilers, tubular air preheaters have the following characteristics and considerations:
Advantages
1. **High heat transfer efficiency**
– The design of tubular air preheaters usually allows flue gas and air to flow inside and outside the steel pipe separately to achieve countercurrent heat exchange, which can effectively improve the heat transfer efficiency.
– Since thin-walled steel pipes are used as heat transfer elements, their large surface area to volume ratio is also conducive to the rapid transfer of heat.
2. **Good sealing**
– The joints of tubular air preheaters are usually strictly sealed to reduce air leakage and maintain a high internal pressure, which helps to improve the thermal efficiency of the entire system.
– Good sealing also means that the intrusion of external impurities can be reduced, the heat exchange medium can be kept pure, and the heat exchange efficiency can be improved.
3. **Easy to manufacture and maintain**
– The structure of tubular air preheaters is simple, the manufacturing process is mature, and it is easy to mass produce and quality control.
– Maintenance and overhaul are relatively easy, because the replacement and cleaning of steel pipes are simpler than other complex structures.
Disadvantages
1. **Large volume**
– Due to the use of tubular structure, the overall equipment of tubular air preheater is relatively large and occupies more space, which may be a problem in space-constrained application scenarios.
– Large equipment also means higher transportation and installation costs, and requires greater infrastructure support.
2. **Easy to block and wear**
– Fly ash is easily accumulated inside the steel pipe, which not only affects the heat exchange efficiency, but also increases the difficulty of cleaning, especially in the internal area that is not easy to reach.
– The steel pipe at the flue gas inlet is susceptible to wear due to the scouring of high-speed flue gas, which requires regular inspection and replacement, increasing maintenance costs.
3. **Low-temperature corrosion problem**
– In low-temperature environments, especially in flue gas with acidic substances, the surface of the steel pipe may corrode due to condensation, which not only affects the service life of the equipment, but also may bring safety hazards.
– In order to prevent corrosion, more corrosion-resistant materials can be selected or anti-corrosion measures can be taken.
In general, the advantages and disadvantages of tubular air preheaters, as well as actual application requirements and environmental conditions, need to be considered during their design and use. For example, in order to reduce dust accumulation and wear, the flue gas velocity and flow direction design can be optimized, and more suitable materials and surface treatment technologies can be selected. For low-temperature corrosion problems, the use of anti-corrosion materials or coatings, as well as improving flue gas composition and temperature control can be considered. Through these measures, the advantages of tubular air preheaters can be maximized while reducing their potential shortcomings.