脱硫废水低温烟气蒸发零排放系统平衡计算

2019年7月在湖北鄂州发电厂投运了一套利用低温烟气余热蒸发脱硫废水的零排放处理系统。为了优化该系统运行操作参数,在投运初期调整试验过程中采用系统水平衡、盐平衡和热量平衡等计算方法进行了平衡试验研究。结果表明:在系统稳定运行条件下,处理脱硫废水能力达到16.19 m3/h;系统烟气放热和浆液吸热基本达到平衡;排泥量(泥与废水质量比)控制在0.165可维持系统盐平衡。

脱硫废水低温烟气蒸发零排放工艺研究

电厂生产中采用湿法脱硫工艺会产生脱硫废水,而脱硫废水的直接排放会严重影响生态环境。目前脱硫废水的常规三联箱工艺处理后的出水的含盐量高,已不符合最新的废水排放要求,因此需要一种彻底解决脱硫废水的工艺。低温烟气蒸发零排放技术可有效地处理脱硫废水,并最终实现废水零排放。为了充分提高相关技术的应用效果,本文结合脱硫废水和低温烟气的特点,重点探索低温烟气蒸发相关技术在脱硫废水零排放处理方面的应用。

脱硫废水高温烟气蒸发过程中氯盐和铵盐的分解

为实现脱硫废水零排放,脱硫废水高温烟气蒸发结晶技术逐渐发展起来,脱硫废水蒸发过程中结晶盐的高温分解可能是制约蒸发技术进一步推广应用的关键问题。介绍了火力发电厂脱硫废水的特点及蒸发结晶过程中盐分的稳定性,重点介绍了水合氯化镁的几种热分解机理。综合分析表明,在旁路高温烟气蒸发处理过程中,氯化镁和铵盐可热分解,分别产生氯化氢气体和氨气,将会引起后续脱硫废水排放量增加、烟囱出口氨浓度升高。最后讨论了旁路高温烟气蒸发系统引起电厂粉煤灰的质量降低等问题。

Optimal Analysis of Pure Low-Temperature Waste Heat Recovery Generation System

In this paper, a detailed thermodynamic analysis of the pure low-temperature waste heat recovery generation system is presented. The parameters affecting the system performance are compared to obtain the most significant ones; furthermore, parameter values are optimized for the largest power generating capability of the system. It is found that the most important parameters are inlet flue gas temperature, steam pressure and the pinch point temperature difference. There is an optimal superheated steam pressure value for giving the maximum generation power per unit flue gas. With the increase of inlet flue gas temperature, the generating power increases and the optimized steam pressure rises as well. However, with increase in pinch point temperature difference, the generating power decreases and the optimized steam pressure decreases as well. The theoretical calculation provides a theoretical basis for the parameters optimization in the design of the pure low-temperature waste heat recovery eeneration swtem