Water-heat-medium air preheater is a new type of energy saving equipment (Patent No. ZL 2006 2 0043 771.X, ZL 2007 2 0076 364.3) developed by Qiyao Energy in order to fully recover the waste heat in flue gas (by reducing exhaust temperature) and prevent low temperature dew point corrosion of heating surface (to ensure prolonged operation of equipment).
Water-heat-medium air preheater is one kind of energy saving equipment hat, with water as heat mediu takes advantage of waste heat in the flue gas from boiler or heater to increase the combustion aire temperature. As an air preheater, it absolutely eliminates such inherent problems of conventional air preheater as frequent air leakage and corrosion of heating surface at low temperature end, and thus substantially reduces the time of emergency shut-down and maintenance work of boiler or heater. In addition, owing to the simple process, flexible arrangement and easy operation, the water-heat-medium air preheater can be used to heat other media, which considerably improves the adaptability and reliability of boiler or heater.
The water-heat-medium air preheater is widely applied to the waste heat recovery of heaters for atmospheric & vacuum distillation unit, hydrogenation unit, hydrogen unit, coking plant and other plants in petrochemical enterprises and waste heat utilization and energy saving reconstruction of heaters, thermal oxidizer and power boilers fueled by coal, oil and gas.
High corrosion resistance;
Prolonged safe operation period;
Increased adaptability and reliability of boiler or heater
In the 1MT/A coking unit of SinoPec Jiujiang Company, the heaters use water-heat-medium air preheater to recover the heat from the low temperature flue gas at the end of the heater. High temperature tubular air preheater and flue gas heat exchanger were respectively arranged in the flow direction of the flue gas of the heater. The air heat exchanger was arranged at the outlet of the blower and the cold air was delivered to the high temperature air preheater after the air heat exchanger.
The water-heat-medium air preheater, reducing the emission temperature from the heater to 160℃, fulfilled the task of energy saving and prevented dew point corrosion at the tube wall of the heating surface and thus ensured prolonged stable operation of the unit.