This project belongs to the technical field of thermal power generation. Through a series of key technology research and integrated innovation, the high energy consumption problem that has long plagued the flue gas desulfurization system of thermal power plants has been solved, and the comprehensive energy consumption of the desulfurization system has been reduced to "zero." It has solved a series of bottleneck problems in the international thermal power generation technology field such as "low-temperature flue gas corrosion and low-temperature flue gas heat recovery", and mastered core technologies and independent intellectual property rights. The research results of this project have been successfully applied for the first time in the million-kilowatt ultra-supercritical unit of Shanghai Waigaoqiao No. 3 Power Plant on May 19, 2009. The operating coal consumption has dropped by 2.71 g/kWh, and the annual standard coal has been saved by 32,000 tons; the annual water saving is 520,000 tons; and the annual plant electricity consumption is 8.44 million kilowatt hours. In the past three years, the cumulative new profit has been 67.79 million yuan, and the success of this technology has quickly attracted strong attention from the industry.
This project has conducted comprehensive research on how to solve low-temperature corrosion and ash blocking of heating surfaces during the flue gas desulfurization process, establish an automatic heat transfer pipe wall temperature control system, improve low-temperature flue gas heat energy recovery efficiency, and reduce auxiliary power consumption. A series of innovative technologies including the following major pioneering technologies have been developed. 1. Low-temperature flue gas waste heat recovery and utilization technology: It breaks through the limitation of traditional GGH that only recovers and does not utilize waste heat. A special heat recovery device is set up and placed at the entrance of the desulfurization tower to greatly cool the flue gas and then introduce it into the desulfurization tower. While ensuring the best desulfurization effect, the residual heat of the furnace flue gas, plus the work temperature rise of the induced draft fan and the booster fan, is comprehensively utilized in the steam turbine recuperation system, significantly improving the overall efficiency of the unit. 2. Low-temperature corrosion control technology for heat transfer pipes: Breakthroughs have solved the metal low-temperature sulfuric acid corrosion problem that has long restricted the recovery of low-temperature flue gas waste heat. In-depth research was conducted on the anti-corrosion characteristics of various metal pipes and the condensation characteristics of sulfuric acid dew, and key technologies for dual acid corrosion prevention and control of "material corrosion resistance" and "wall temperature control to prevent dew condensation" were developed. 3. Automatic control system for heat transfer tube wall temperature: It is the first to solve the impact of unit load changes on the working conditions of the heat transfer tube, realize full-process automatic control of wall temperature, and ensure the operating safety of the heat exchanger. 4. Air preheater sealing optimization and low-oxygen combustion technology: The newly developed air preheater adaptive sealing technology and boiler low-oxygen combustion technology reduce the exhaust gas volume by 9%, which significantly reduces fan power consumption while effectively improving and truly reflecting the boiler exhaust gas temperature. It frees up valuable flue gas pressure drop for the addition of smoke and water heat exchangers, and creates valuable conditions for further improvement of the average temperature and pressure of smoke/water and operating performance of the waste heat recovery system. 5. Comprehensive energy-saving operation technology for fans: Through in-depth research on the resistance characteristics of the air and smoke system, a comprehensive energy-saving operation technology for fans has been developed to reduce the power consumption of desulfurization auxiliary machines while improving the operation safety of fans.
This project has obtained 1 authorized national technical invention patent, 3 utility model patents, and 2 papers have been published in academic journals and conferences at home and abroad. The main research results of this project belong to general technology and are widely applicable to the renovation of new units and old units. They can reduce the coal consumption of unit power supply by 2.5-3 g/kWh on average. For units with higher exhaust temperatures, the benefits are more significant. At present, this technology has been applied in a considerable number of domestic power plants. If this achievement is fully promoted, about 10 million tons of standard coal can be saved and about 27 million tons of CO2 can be reduced every year across the country. Through the application of this technology, the comprehensive energy consumption of the desulfurization system can be reduced to zero or even a slight surplus. Coupled with the subsidy for desulfurization prices, the desulfurization system has subversively transformed from a "burden" of energy consumption to an economic growth point for the first time, making the power plant The previous "want me to desulfurize" has changed the traditional passive environmental protection awareness and made huge contributions to my country's power environmental protection and energy conservation.