海绵钛生产还原过程余热回收试验研究

发布时间：2018-08-14 16:58

【摘要】：国内外海绵钛生产主要是镁还原-真空蒸馏法(又称Kroll法或联合法)。其中,还原-蒸馏工序和镁电解工序是两个主要耗能工序,我国海绵钛企业在设备改造、工艺操作优化等节能降耗技术开展了大量卓有成效的工作,但对还原—蒸馏工序和镁电解工序的余热资源未进行回收利用。论文针对海绵钛生产的还原-蒸馏过程在能耗水平方面与日本等先进国家差距,开展余热资源回收试验研究,其主要工作如下:首先,以还原过程余热空气资源为研究对象,利用热力学第一定律,对其进行热工测试,计算分析还原过程中余热空气的散热参数。测试结果表明:余热资源是分布式产生,存在温度的分布点不集中等问题,对还原设备余热空气的温度、流量和散热功率的分布状况进行数理统计分析,根据其置信区间得到余热资源参数的大致波动范围。其次,对余热回收的列管换热器和热管换热器进行了热力计算和结构布置设计,得到换热设备的主要参数,并对两种换热器的性能以及优缺点进行对比分析。结果表明:列管换热器其传热面积大,适应性强,但从余热回收效率、压力损失、防止堵塞、清洗、寿命等综合指标看,热管换热器在各方面有着明显的优势,但其设备成本也相对较高。最后,根据余热资源产生和分布规律,选择合适的材质和流体介质,利用设计的列管换热器和热管换热器,在我国某钛厂的还原蒸馏炉开展余热回收试验研究。试验结果表明:从回收效率的波动来看,前期的回收效率也较低,生产稳定后热回收效率逐渐稳定。在生产稳定后,列管的热水温度在70~75℃之间波动,瞬时质量流量主要集中在810~870kg/h区域;热管的热水在85~90℃之间波动,热水的瞬时质量流量在800~900kg/h之间波动。热管换热器余热回收所得水温较高。论文的研究成果已成功在海绵钛企业工业化应用,对进一步强化钛行业节能减排,提高海绵钛企业和产品的竞争能力,提高海绵钛生产过程的资源、能源利用效率具有重要的意义。
[Abstract]:Sponge titanium production at home and abroad is mainly magnesium reduction-vacuum distillation (also known as Kroll method or combined method). Among them, reduction-distillation process and magnesium electrolysis process are two main energy-consuming processes. In China, sponge titanium enterprises have carried out a lot of fruitful work in energy saving and consumption reduction technology, such as equipment transformation, optimization of process operation, etc. However, the waste heat resources of reduction-distillation process and magnesium electrolysis process are not recycled. Aiming at the gap between the energy consumption level of reduction-distillation process in sponge titanium production and Japan and other advanced countries, the paper carries out the experimental research on waste heat resource recovery. The main work is as follows: firstly, the waste heat air resource in the reduction process is taken as the research object. The first law of thermodynamics is used to calculate and analyze the heat dissipation parameters of the waste heat air in the reduction process. The test results show that the waste heat resources are distributed and the temperature distribution points are not concentrated. The distribution of residual heat air temperature, flow rate and heat dissipation power of the reduction equipment is analyzed by mathematical statistics. According to its confidence interval, the fluctuation range of the parameters of waste heat resources is obtained. Secondly, the thermal calculation and structural layout design of the row tube heat exchanger and the heat pipe heat exchanger are carried out, and the main parameters of the heat exchanger are obtained, and the performance, advantages and disadvantages of the two heat exchangers are compared and analyzed. The results show that the heat transfer area of the tube heat exchanger is large and the heat transfer adaptability is strong. However, the heat pipe heat exchanger has obvious advantages in all aspects from the comprehensive indexes of recovery efficiency, pressure loss, prevention of blockage, cleaning and service life of the heat pipe heat exchanger. But its equipment cost is also relatively high. Finally, according to the generation and distribution of waste heat resources, the waste heat recovery test was carried out in a reduction distillation furnace in a titanium plant in China by selecting suitable material and fluid medium and utilizing the designed tube heat exchanger and heat pipe heat exchanger. The experimental results show that the recovery efficiency is also low in the early stage, and the heat recovery efficiency is gradually stable after the production is stable. After stable production, the temperature of hot water fluctuates between 70 鈩，

本文编号：2183516