电厂采用的制氨方法有尿素热解法和水解法,针对某电厂300 MW机组利用Aspen Plus软件对比分析了2种方案的优劣,从水解制氨系统的尿素进料质量分数、反应温度及压力3个方面,分析了不同反应条件对水解产物的影响.结果表明:水解方案反应温度低,可采用低品质蒸汽作为热源且能耗量仅为热解的20％～30％,从节能角度出发,水解制氨为最佳方案;随尿素进料质量分数的增加,产氨量增加,耗热量降低,但液相中尿素质量分数也随之升高,易发生设备腐蚀;随着温度的上升,尿素水解速率提高,但耗热量上升明显,经济性较差;增加压力能降低设备发生腐蚀的风险,但会对气体的析出产生抑制;综合考虑,尿素水解反应条件为尿素进料质量分数50％,温度150～160℃,压力0.6～0.8 MPa比较合适.%The ammonia production methods used in power plants include urea pyrolysis and hydrolysis.Numerical simulation was conducted by Aspen Plus for the two processes in a 300 MW coal-fired power plant.From the aspects of urea feed mass fraction, reaction temperature and pressure, the effects of reaction condition on hydrolysis products were investigated. The results show that, compared with pyrolysis, the hydrolysis scheme has a lower reaction temperature, its energy consumption is only about 20％～30％ of that of pyrolysis. What's more, low-quality steam can be used as the heat source of the hydrolysis scheme. From the point of energy saving, hydrolysis to ammonia is the best method. The simulation result shows a same tendency with the experimental data, verifying the reliability of the hydrolysis model. When the urea feed mass fraction was increased, the ammonia concentration in the product gas increased, the heat consumption decreased, while the urea in the liquid also increased, which leads to a rise in the risk of corrosion. As the temperature increased, the urea hydrolysis rate increased, but the heat consumption rose rapidly, and the economy was poor. Increasing the pressure can reduce the risk of corrosion. However, excessive operating pressure will inhibit the release of gaseous products.Considering comprehensively, the condition with urea feed mass fraction of 50％, temperature of 150 °C～160°C and pressure of 0.6～0.8 MPa is suitable for the urea hydrolysis.
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