Experimental Study on Ammonia Co-Firing with Coal for Carbon Reduction in the Boiler of a 300-MW Coal-Fired Power Station

To reduce CO_(2) emissions from coal-fired power plants,the development of low-carbon or carbon-free fuel combustion technologies has become urgent.As a new zero-carbon fuel,ammonia(NH_(3))can be used to address the storage and transportation issues of hydrogen energy.Since it is not feasible to completely replace coal with ammonia in the short term,the development of ammonia-coal co-combustion technology at the current stage is a fast and feasible approach to reduce CO_(2) emissions from coal-fired power plants.This study focuses on modifying the boiler and installing two layers of eight pure-ammonia burners in a 300-MW coal-fired power plant to achieve ammonia-coal co-combustion at proportions ranging from 20%to 10%(by heat ratio)at loads of 180-to 300-MW,respectively.The results show that,during ammonia-coal co-combustion in a 300-MW coal-fired power plant,there was a more significant change in NO_(x) emissions at the furnace outlet compared with that under pure-coal combustion as the boiler oxygen levels varied.Moreover,ammonia burners located in the middle part of the main combustion zone exhibited a better high-temperature reduction performance than those located in the upper part of the main combustion zone.Under all ammonia co-combustion conditions,the NH_(3) concentration at the furnace outlet remained below 1 parts per million(ppm).Compared with that under pure-coal conditions,the thermal efficiency of the boiler slightly decreased(by 0.12%-0.38%)under different loads when ammonia co-combustion reached 15 t·h^(-1).Ammonia co-combustion in coal-fired power plants is a potentially feasible technology route for carbon reduction.

Research of Boiler Combustion Regulation for Reducing NOx Emission and its Effect on Boiler Efficiency

The effect of boiler combustion regulation on NOx emission of two 1025t/h boilers has been studied. The researches show that NOx emission is influenced by coal species, operation conditions, etc, and can be reduced by regulating the combustion conditions. The effect of combustion regulation on boiler efficiency has also been checked.

Feasibility of Combustion of Petroleum Coke in 230t/h Circulating Fluidized Bed Boiler

In order to reuse the high sulfur petroleum coke, the waste in chemical industry, as fuel of power plant for energy recovery, the combustion property of petroleum coke was researched experimentally in circulating fluidized bed (CFB) boiler. The performance of the boiler in burning mixed fuel with different ratios of coal to petroleum coke is obtained. Based on the experimental data, Factors influencing the stability of combustion,thermal efficiency of boiler, and emissions and desulphurisation are discussed. This study demonstrates that the combustion of petroleum coke in CFB boiler is applicable, and has great significance on the design and operation of CFB boiler to burn petroleum coke.

Paper Machine Influence on Industrial Energy System

In this paper, the influence of low power factor on electricity system and the influence of paper breaking on heat system are presented. For that, a mathematical model and a case study for a paper mill are realised. The electric mathematical model is based on the relations of energy losses in cables and in transformers as a function of power factor. The thermal mathematical model includes characteristic energy and efficiency of boiler depending on its load. Characteristic of efficiency is modeled by a quadratic dependence between fuel consumption and steam flow. In the case, study were estimated to reduce energy losses for factor neutral （0.92） against real power factor （0.75） for the electrical scheme of a paper machine. Analytical expression of the boiler characteristic and variation of boiler efficiency depending on its load were estimated, too.

PM10 emissions from industrial coal-fired chain-grate boilers

Industrial coal-fired boiler is an important air pollutant emission source in China. The chain-grate boiler is the most extensively used type of industrial coal-fired boiler. An electrical low-pressure impactor, and a Dekati？ Low Pressure Impactor were applied to determine mass and number size distributions of PM10 at the inlet and the outlet of the particulate emission control devices at six coalfired chain-grate boilers. The mass size distribution of PM10 generated from coal-fired chain-grate boilers generally displays a bimodal distribution that contains a submicron mode and a coarse mode. The PM in the submicron mode for burning with raw coal contributes to 33% ± 10 % of PM10 emissions, much higher than those for pulverized boilers. And the PM in the submicron mode for burning with briquette contributes up to 86 % of PM10 emissions. Multiclones and scrubbers are not efficient for controlling PM10 emission. Their average collection efficiencies for sub-micron particle and super-micron particle are 34% and 78%, respectively. Operating conditions of industrial steam boilers have influence on PM generation. Peak of the submicron mode during normal operation period is larger than the start-up period.