Project introduction:

In northern China, due to water shortage, the development of thermal power units has been greatly restricted. Due to the shortage of water consumption indicators, many new power plants often have to adopt dry desulfurization systems with large investment, high operating costs, and low desulfurization efficiency. The initial investment of a dry desulfurization system for a 600MW unit reaches 700 - 800 million yuan, while the wet desulfurization system with high desulfurization efficiency only needs 120 - 150 million yuan. Therefore, it is very necessary to study significantly reducing water consumption in wet desulfurization systems and has a huge application background.

Results Advantages:

The flue gas is generally saturated when passing through the desulfurization tower and will carry away a large amount of water. For wet desulfurization systems, the amount of water brought to the atmosphere by saturated flue gas accounts for more than 90% of the water consumption of the entire system. By reducing the temperature of the flue gas after desulfurization, saturated wet flue gas will condense, a large amount of water can be recovered, system water consumption can be greatly reduced, and zero water replenishment can be achieved for wet desulfurization. However, since the flue gas temperature at the outlet of the desulfurization tower is generally about 50℃, there is a problem of low-temperature corrosion. At the same time, there is still a lack of systematic research on the structure and heat transfer coefficient of the condensing heat exchanger, the recovery efficiency of condensate water, and the recycling methods of low-grade heat. Therefore, there is currently no precedent for the mature application of this technology in large coal-fired units at home and abroad. In recent years, the School of Dynamic Action of Xi'an Jiaotong University has explored the possibility of recovering water from the flue gas of coal-fired power plants, and obtained detailed test data, which can provide support for the industrial demonstration application of this topic.

This topic will experimentally study the influencing factors and laws of the moisture and heat recovery process of the flue gas at the outlet of the desulfurization tower, and analyze specific problems in the industrial implementation plan to provide a theoretical and experimental basis for the water-saving project of the wet desulfurization system.