In the process of pipe construction and data accumulation in such industrial projects as synthetic ammonia&urea projects,the section calculation formula for solder consumption under different groove forms is derived based on various common welding groove section forms in the actual welding process.The formula is modified as per practical experience to summarize an optimized and simplified calculation formula that could generate calculation results close to the actual solder consumption.Practice shows that the solder consumption calculated by the simplified formula is very close to the actual usage,which simplifies the statistical process of solder amount calculation and improves its statistical efficien-cy.
The new manufacturing process of closure is related to the manufacturing process of various closure structures in the field of pressure vessels,and it features the advantages of accurate molding,high efficiency,safety and easy operation,regular shape and size of the closure,and great load-bearing capacity.The new closure manufacturing process is mainly based on hydraulic machinery and electromagnetic heating,using tooling to achieve mechanical forming of the closure,which can adapt to closure structure manufacturing in various pressure vessel equipment,and is especially suitable for large pressure vessel closure manufacturing.
The main engine arrangement sequence of a"motor-generator"steam-electricity double-drive feed pump set has been studied.The re-sult shows that the centered arrangement of"motor-generator"is the best scheme.The difference of pump performance in two models is dis-cussed,the maximum speed of pump is considered,during the pump dynamic analysis.The rotor and bearing of"motor-generator"are designed with increased load.The discussion shows that more reactive power is needed in the power generation case.The requirements of the start-up and shut-down sequences of the unit are discussed.After the unit is put into operation,stable operation and good performance are achieved,and the motor and power generation models are automatically switched smoothly.Finally,the fluctuation of power generation quantity and its influencing factors are analyzed,the result of which shows that the fluctuation of power grid frequency and that of operation slip ratio may be the causes.
A method of separating syngas via gas hydration to produce low carbon olefin product mixture is proposed.Such problems as water filling,heat transfer and temperature control in bubble bed hydration reactor are discussed,and the countermeasures are presented.All in all,the feasibility of separating syngas via gas hydration to produce low carbon olefin product mixture is discussed.
In the production of compound fertilizers,stable operation of the screening system is directly related to production continuity and prod-uct quality.Most of the traditional system adopts roller screen and vibrating screen types.The new plane rotary screen allows materials to quickly pass through,thanks to a specific reciprocating rotary motion mode and a low inclination of the screen surface.It features a larger effec-tive screening area,better screening efficiency and higher output.At the same time,it is equipped with self-tensioning and self-cleaning screen installation system to achieve the ideal screening effect for compound fertilizer production.After the plane rotary screen is applied to the screen-ing system,the granularity accuracy of the finished product is increased from 80%to more than 95%,the screening capacity is increased,and the product quality is also greatly improved.
The main sources,composition and comprehensive utilization status of C4 hydrocarbons are analyzed,and the main technologies for in-creasing propylene output from C4 hydrocarbons are reviewed.In view of the technology of using C4 resources as by-products in domestic coal-to olefin projects,the feasible schemes for comprehensive utilization of C4 resources are discussed,and it is pointed out that C4 cracking technol-ogy for increasing propylene output is more competitive.
Targeting at traditional nitrogen water pre-cooling processes in the Air Separation Pre-cooling Unit,and considering serious water shortage on job sites,a new low-temperature water process of replacing the water cooling collumn with steam-type lithium bromide chiller is proposed.An in-depth comparison and analysis is conducted between the new process and the traditional one.The results show that the new process not only saves energy and consumption,but also makes operation of the unit safer.
The on-site hydrogen production plants mainly adopt the following three processes for hydrogen production:hydro-electrolysis,natural gas-steam reforming and hydrogen production via methanol.The information on Faraday Theory of Electrolysis,energy balance,process flow,technical parameters,utilities and main equipment for hydrogen production via water electrolysis is introduced.Selection of electrolyte and elec-trode material bears greatly on energy consumption and reliability of the plant.The purification unit adopts catalytic reaction and physical ad-sorption to deeply remove impurities such as water and oxygen,which serves as the key to hydrogen quality guarantee.
Methanol feed is key to the production of methanol to olefin units.The quantity and temperature of methanol feed directly affect the reaction temperature and the yield of the product.During methanol feeding,it is common to find condensate methanol liquid in the gas phase feed pipe.In the original design,such methanol liquid is directly discharged into the sewage tank through the dewatering package,and then pumped to the waste methanol tank through the sewage.By modifying the feed facilities,the liquid phase methanol of the dewatering package is recovered directly,and such goals as lower discharge frequency,lower power consumption,smaller methanol loss and reduced load of the wastewater stripper are achieved.
Problems regarding construction schedule,quality and safety management and control have been caused due to different construction methods adopted in the installation andjacking of low-temperature storage tank vault structure.Based on the analysis of vault structure,instal-lation characteristics andjacking process of large low temperature storage tanks,such measures as modular prefabrication and vault structure in-stallation standardization,standardization of air-blown jacking equipment as well as work flow standardization are summarized and put forward.Practice has proved that the above measures reduce the input of operators,large cranes and transportation equipment,improve the construction efficiency,speed up the installation schedule,reduce the operation safety risks,as well as improve the construction quality and turnover of tools and instruments.
In view of the anti-corrosion problems of chemical water treatment equipment in power plants,the problems existing in the anti-corro-sion process are analyzed,and feasible countermeasures are summarized in the view to providing reference for improving the quality and efficien-cy of chemical water treatment in power plants.
Urea high-pressure equipment is the core equipment in urea unit.Through assessing the risks in the design,manufacture and operation of such equipment,and analyzing the failure mode,various factors causing equipment failure are discussed,and specific countermeasures are pro-posed based on the corrosion mechanism and engineering experience,so as to ensure the intrinsic safety of the equipment.
As a kind of water transport structure,aqueduct is often built on valleys,depressions,rivers and highways for high-altitude water transport operation.In the construction process,although the participating parties strictly control the construction quality,there could always be some problems during construction because of certain objective factors,such as cracks and seepage in the concrete of the aqueduct due to vari-ous reasons.In view of such seepage problem,the maintenance method of"polyurea grouting for seepage prevention and polymer waterproof mortar for reinforcement"has been adopted,solving the problem of cracks and seepage in the aqueduct desirably.
Air separation compressor of Henan Longyu Coal Chemical Co.,Ltd.is the multi-axis type with unique structure;its vibration between rotors at various levels features mutual influence,leading to complex vibration failures.This paper briefly describes the recent vibration failures of air separation compressor,conducts analysis&diagnosis on the compressor and studies corresponding treatment measures in light of the actu-al field maintenance situation.It is concluded that vibration fault analysis bears good engineering application value.
At present,the regenerative cycle with intermediate reheating is widely used in all thermal power generation units to improve the ther-mal economy of the whole boiler and turbine unit.High pressure feed water heater is an important piece of equipment in the heat-regenerative system,and it features a high leakage rate due to design,installation,maintenance and operation reasons.Through analysis of piping axial and thermal stress of two 2.5 MW units of high pressure feed water heaters,this paper puts forward the point of controlling the temperature change during the start,stop and operation of high pressure feed water heaters,and solves the problem of frequent leakage of high pressure feed water heaters.
In LNG terminals,a lot of cold energy is released during LNG vaporizing.Seawater is usually used as a heat source for LNG vapori-zing,which not only wastes LNG cold energy resources,but also causes cold pollution to the surrounding marine environment.In recent years,with the booming development of the internet comes an explosive growth in the demand for data computing,storage and transmission,etc.More and more internet data centers have been constructed,the operation of which entails a lot of electricity consumption.To ensure normal and stable operation of internet data centers,a lot of cold energy needs to be consumed for heat dissipation.This paper focuses on analysis of the technology and economy of the coupled utilization of internet data centers and LNG cold energy-cold and heat sources.The analysis results show that it bears obvious energy saving and emission reduction effects and is feasible in both technical and economic terms,which makes it able to provide certain reference for related industries.
某合成氨制尿素装置高压甲铵冷凝器在设备更新改造后的首次定期检验中,发现低压侧壳体焊缝处出现非正常腐蚀冲刷.为了保障设备运行的本质安全,通过收集设备运行数据、检测焊缝腐蚀程度、对比更新改造前后新旧设备的设计和制造方面存在的区别,最终发现设备原始设计缺陷和空泡腐蚀是导致异常腐蚀的主要原因,并依据分析结果合理地制定了检修策略,消除缺陷,降低装置运行风险.同时分享了高压甲铵冷凝器焊缝缺陷修复方案,为同类型设备出现相似缺陷提供借鉴.
因循环利用资源,钢化联产项目的经济效益、环保效益和社会效益显著,受到行业关注.其中,项 目的一项关键技术是转炉煤气的深度净化.针对转炉煤气组分的特点,研究了转炉煤气中羰基硫的水解机理,氧气的脱除机理,研发出适宜转炉煤气脱除羰基硫等硫化物的工艺技术,脱除氧气的复合氧化物催化剂.运行结果表明,经过净化后的转炉气总硫含量可以达到＜0.1 mg/m3,氧气含量可以达到＜30 mg/m3,满足化工生产的要求,推进了钢化联产协同降碳技术推进速度,具有很好的工业应用前景.
通过实际工程项目,总结出铜包钢复合材料接地系统施工方法,使用铜包钢复合材料,能够有效克服电镀法和套管包覆法存在的结合力差的缺陷,不仅铜层厚、耐腐蚀性能好,而且具有安装方便、电气连接性能好等优点,与传统施工方法相比,成本大幅降低,具有一定的经济效益和社会效益.
