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锅炉排污是锅炉水质控制的一个重要的环节.合理的排污对保持炉水和蒸汽的品质、防止锅炉结垢、提高锅炉寿命、节约能源都有重要的作用。 相似文献
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今年6月,我厂一台8吨/13公斤沸腾锅炉先后发生了三次爆管事故,被迫停炉中修。爆管中,有几根沸腾管堵塞,且多在左侧。 经检查分析,找到了爆管的原因。一是盲目改变下汽包排污出口结构。这台锅炉水循环系统结构如图1所示。 这台锅炉原设计定期排污炉水是通过虹吸管,再经排污管、排污阀排至炉外的。可是后来却在汽包内部排污管接近汽包壁处开了两个直径约30毫米的孔(见图2)。虽然孔只有两个,但是它们可使排污虹吸管短路,并失去作用。每当排污时,汽包左侧积存沉淀物很快就从排污管排至炉外,汽包右侧沉淀物也随排污水流至左侧。因为排污时间不能… 相似文献
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4 月 29日 中 午,上海日用化学 品厂一台锅炉刚开 始排污,司炉听到 另一台停炉的锅炉 内有呼救声,并发 现蒸汽外冒,就立 即关闭排污阀,在 停炉内的三名敲铲 工人已烫伤一人。 事后检查发 现,停炉锅炉与运 行锅炉的排污管路 是相通的,敲铲前 未采取隔绝措施, 停炉锅炉的排污阀 也未关闭。当运行 锅炉排污时,排出 的炉水经开启的排 污阀倒灌到停炉的锅炉内,引起了这起事故。 为了杜绝此类事故,我们认为,锅炉使用单位检修人员进入锅筒内工作以前,须用能指示出隔断位置的强度足够的金属堵板,全部可靠地隔断与其它运行锅炉联接的蒸汽、给水和排污… 相似文献
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“SHW”型小吨位的工业锅炉水冷壁联箱排污时,由于结构上的缺陷,会造成水冷壁供水不足,引起上半部瞬间缺水;严重时,会使管子过热胀粗,甚至发生爆管、炉膛爆炸。 剖析“SHW”型锅炉水循环系统(见图 1),大致可分成对流管束和水冷壁两大部分。对流管束部分定期排污门设在下锅筒和防渣管联箱处。上锅筒有两个水位计,锅炉上水直接进上锅筒。排污时有水位监视、能及时补充足够的水量,不论在运行工况或排污工况下,都能有效地防止缺水。水冷壁部分是按下降管、水冷壁管、输汽管的截面比例严格地设计的,正常运行时不会造成缺水。但在排污工况下,由… 相似文献
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The exploitation of a low-quality gas field with high CO2 concentration is more viable through liquid CO2 produced from cryogenic distillation technology. Despite the bright potential of the technology, there are deficiencies in handling high concentration of CO2 at low temperature and high pressure during the blowdown condition. This study focuses on the CO2 blowdown at a cryogenic pilot plant designed to manage high concentrations of CO2 in the feed gas, high pressures, and low temperatures. A comprehensive design review and risk assessment using Inherent Safer Design (ISD) indexes were carried out in this study. The ISD was performed to identify the current risk level, and the critical parameters that may cause solid CO2 formation in the piping or equipment as well as to identify mitigation measures to avoid the temperature to drop below the CO2 freezing point during blowdown. The present findings confirmed that the initial pressure and temperature, as well as CO2 concentration are key parameters towards significant impact on blowdown conditions. Therefore, the reduction of the feed gas pressure from 80 bar to 70 bars has minimized the Joule Thomson (JT) effect during blowdown and avoided the CO2 solid formation in the system. Moreover, the relocation of the blowdown valve at the downstream heater resulted in a higher final temperature above the CO2 freezing point. The ISD indexes confirmed that the cryogenic facilities are inherently safer during blowdown with the mitigation measures adopted. 相似文献
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Cryogenic distillation columns are generally subjected to high-pressure loadings during the natural gas purification process. The high-pressure conditions inside the column cause safety risk e.g. rupture. When an emergency arises, blowdown is a typical way of minimizing the failure hazard. However, blowdown at the cryogenic conditions involves dry ice formation due to the rapid decrease in temperature driven by the Joule-Thomson effect. The dry ice formation intensifies the failure hazard due to the orifice blockage. Therefore, optimization of blowdown parameters is necessary to avoid the dry ice formation. So far, very limited studies are available in the literature for the blowdown of CO₂-CH₄ mixture, especially at the cryogenic conditions. In this study, a computational investigation followed by the experimental validation is accomplished to analyze the dry ice formation during blowdown of CO₂-CH₄ binary mixture from the cryogenic distillation column. The composition of mixture, orifice size, and initial conditions inside vessel have a high impact on blowdown path. A 3.00 mm orifice is the most suitable size for the blowdown at cryogenic conditions as it doesn't promote solidification and discharges the inventory quickly. Based on the experimental observation, an empirical correlation is also developed to instantly find out the optimum blowdown parameters. 相似文献
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碱回收锅炉是碱法和硫酸盐法造纸工艺的关键设备,我国现阶段碱回收炉均采用自然循环敷管炉墙全钢架吊挂结构,炉膛采用鳍片水冷壁、全密封焊接而成。通过对碱回收锅炉结构及运行特点进行分析,结合实际介绍了碱回收炉设计制造、安装过程、监督检验过程提高安全性的一些强化措施,并指出了在安装和检验过程应重点关注的一些问题。 相似文献
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通过对省煤器泄漏原因进行分析,得出造成泄漏的主要原因是由于近期锅炉燃料配比改变导致锅炉实际燃烧工况发生了变化,使省煤器沸腾度超过设计值,由此在省煤器蛇形管弯头和汽包布水管内壁产生汽水冲刷,使管壁减薄,最终爆开。采用减少锅炉省煤器管换热面积,降低省煤器沸腾度,并同时对汽包布水管缩径,增加锅炉给水在水平管道流速的方法,彻底消除了焦耐锅炉省煤器频繁泄漏现象,保障了3台锅炉安全连续运行。 相似文献
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电站锅炉的压力管道参数较高,存在着较大的安全风险,一旦发生事故,后果往往十分严重.电站锅炉的压力管道在按照"锅炉"或"压力管道"进行管理时,设计、制造、安装等阶段管理要求存在交叉或不清晰的情况.进行定期检验时,又有按锅炉范围内管道或工业管道(含动力管道)执行不同技术规范的情况.本文通过按"锅炉"和"压力管道"管理时执行... 相似文献
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针对河北省某厂的燃煤锅炉的烟管腐蚀问题,通过水质分析、采集腐蚀处的产物,进行XRD、扫描电镜、能谱分析等手段分析腐蚀产生原因和腐蚀速率的影响因素.发现烟管与水接触侧发生了氧腐蚀.水垢附着速率、溶解氧含量这两种因素对腐蚀速率影响较大.并针对锅炉材质、锅炉设计、水质处理、停炉保养、人员素质等方面提出改进措施,为今后处理类似问题提供经验和参考. 相似文献
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R.S. Ettouney M.A. El-Rifai A.A. Elzoubier 《Journal of Loss Prevention in the Process Industries》2012,25(4):739-745
The evolution of pressure, temperature, and gas inventory during containment of blowdown from two high pressure gas networks into a third lower pressure relatively large redundant pipeline is followed through a simple lumped parameter model. Numerical solution of the non-linear model equations enabled to study the effects of relevant operating conditions on the system's dynamics. The effects of initial pressure difference between the supply and receiving networks, ratio of discharge orifice to pipe diameters in the supply networks, and heat transfer from the surroundings are investigated. A set of computer generated results are presented to demonstrate vividly the effect of the above variables on the percent of gas recovered in the lower pressure pipeline, the blowdown time, and the minimum temperatures reached in the networks. 相似文献
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电建单位在安装水冷壁等电站锅炉产品时,首先在地面的组装平台上根据设计总图,将单屏摆拼焊接之后,再整体起吊安装,对于组装时发现的形位尺寸问题只能现场解决。本文主要探讨了在锅炉制造企业内部模拟现场组装条件进行预组装,介绍了电站锅炉管屏产品的结构特点、厂内预组装的意义、预组装工装设计、技术条件以及预组装前后质量的对比分析,通过加强管控和优化工艺流程等手段提高厂内制造精度,保证设备顺利安装。 相似文献
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Davide Manca Sara Brambilla 《Journal of Loss Prevention in the Process Industries》2012,25(6):950-957
The paper investigates the causes and simulates the dynamics of the events that led to the catastrophic explosion on March 23, 2005 at the British Petroleum (BP) refinery in Texas City (USA) where 15 people died and 180 were injured.The paper follows the timeline of the accident, investigates the premises that characterized its phenomenology, and performs a critical analysis to fill the gaps that can be found in the scientific literature concerning the accident. In particular, a commercial dynamic process simulator (UNISIM) was adopted and integrated with ad hoc models to explain the column flooding and overfilling, the opening of the relief valves, and the flow of a two-phase mixture into the pipe connected to the blowdown system. The main findings are: (1) that the mass balance and the liquid thermal expansion cannot explain the complete flooding and overflow of the isomerization column; (2) the vapor cap used to explain the column overflow is unrealistic in our opinion; (3) the overflow can be explained by the partial vaporization of the feed stream after 1:00 PM and the consequent dispersion of vapor bubbles into the liquid holdup above the feed tray. In particular, tray holes smaller than 8 mm could cause the overflow; (4) there is a significant change in the thermodynamic conditions of the mixture emitted by the column head (temperature, pressure, vapor/liquid fractions) along the 270 m pipeline that connects the relief valves to the blowdown system; (5) the HEM model, together with the initial conditions we applied cannot explain the blowdown drum filling and release, therefore further studies are necessary. 相似文献