Utilizing the efficiency of ultra-supercritical (USC) steam conditions and the flexibility of circulating fluidised beds (CFB), the Advanced CFB boiler offers 660 MW or more in output, based on the type of fuel. The boiler provides customers in coal-rich markets with the opportunity to reduce operating costs and increase output. By combining the two principles, ZG offers customers a single, highly attractive boiler option, which diminishes fuel consumption and the CO2 footprint by 6% versus plants of comparable size using traditional technology. The boiler is able to achieve this while ensuring fuel flexibility and reliability.
Int he past two decades, because of the three outstanding advantages such as wide fuel flexibility,excellent emission performance and large range of load adjustment, CFB boiler technology developed rapidly and becomes one of the clean coal combustion technologies commercially applied. In China, CFB boiler combustion technology has made an irreplaceable position in the market of small and medium scale boilers.So far,the total number of CFB boiler in commission is over 3,000units.As a developing technology, CFB boiler combustion technology still faces many challenges. For example,in the view of operation safety, though the availability increases greatly by solving erosion,refractory materials and auxiliary equipment, some CFB boilers with 135M. We can continuously operated over 8000h , which is lower than that of the coal fired boiler.In addition, the combustion efficiency of CFB boiler is lower while the service power is 1-2% higher.Even worst is that serious wear of the heating surfaces, especially caused by firing low quality coal, will reduce the boiler’s availability greatly.
Table 1 shows the power of auxiliary equipment in CFB boiler and Coal boiler in 300MWe scale. How to solve these three problems,particularly operation economics,is the key research subject faced by the international researcher and manufacture. the power consumption of auxiliary in CFB boiler is one time higher than that of coal fired boiler. As result, the average service power is as high as 9%.The reasons lies in not only in the problem in boiler design, but also in the complexity of system layout and improper selecting of auxiliary. The first 75t/h CFB boiler with the novel CFB technology by reconsideration of fluidization state has been operated since January, 2006 and a comprehensive field test was carried out in June, 2007. The results proved hat the novel technology can greatly avoid the erosion and reduce the service power. A big breakthrough was made in boiler’s availability and economics.