SPC flue gas dehydration technology
On the principle of different saturated partial pressures of water vapor in saturated purified flue gas at different temperatures, this technology enables heat exchange through direct contact between low-temperature circulating water and saturated purified flue gas, separating some vapor from flue gas while reducing its temperature. Heat in purified flue gas is transferred using two-stage heat exchange method. The first stage is in water removal device where low-temperature circulating water is mixed with high-temperature saturated purified flue gas for heat exchange, cooling the saturated purified flue gas and extracting condensate water. In the second stage, the heated high-temperature circulating water exchanges heat with air cooler (or other cold sources such as heat pump) using gas-liquid bundle type indirect heat exchanger to cool the circulating water.
Application and advantages:
The Beijing Energy Wujianfang Power Plant with a shortage of water employs SPC flue gas dehydration technology to recover water from flue gas, the first application of this technology. The project is ongoing. Once put into operation, SPC's flue gas dehydration system could significantly reduce water consumption by the wet desulfurization system, bringing enormous economic benefit to areas with scarce water resource. Take new 2×660MW coal-fired power generator units which are utilized for 5500h annually. The dehydration system running in economical mode (used for desulfurization only) can recover 844,800t, cutting water consumption per unit of installed capacity by 116.4g/KW. The operating cost is estimated at 4.6 yuan/t on average based on annual water recovery.