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炼油装置加热炉节能途径与制约因素 总被引:1,自引:0,他引:1
加热炉是炼油装置的能耗大户,其节能水平对于提高炼油装置的节能水平具有重要意义。介绍了加热炉主要的节能途径:优化换热流程,降低加热炉热负荷;加热炉与其他设备联合回收余热;降低排烟温度、降低过剩空气系数、减少不完全燃烧损失、减少散热损失以提高加热炉热效率。探讨了上述节能途径的主要技术措施及应注意的问题。阐述了进一步提高加热炉节能水平的制约因素:降低排烟温度,要考虑经济性和露点腐蚀;过分降低炉外壁温度,会导致费用过高;预热空气温度过高对环保不利。提出了进一步提高加热炉节能水平的建议;认真净化燃料,降低露点温度;开发新的余热回收工艺;开发并应用“蓄热式高温空气预热贫氧燃烧技术”等新的燃烧技术;加强运行管理。 相似文献
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介绍了抚顺石化公司乙烯化工厂聚乙烯车间DTA加热炉空气预热器,分析了改造前设备存在的问题及出现问题的原因,制定了改造方案。通过对设备进行改造,解决了空气预热器结露、腐蚀、积灰等影响加热炉正常运行的问题,延长了设备使用寿命和检修周期,有效地回收余热,使加热炉在合理的热效率下运行,燃料气使用量减少60kg/h,降低了生产能耗。 相似文献
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水热媒技术在连续重整装置加热炉烟气余热回收系统中的应用 总被引:1,自引:0,他引:1
为回收加热炉的余热,扬子石化公司在1.39Mt/a连续重整装置应用了水热媒余热回收技术,以中压锅炉给水为热载体,利用从烟气中回收的热量来加热锅炉给水和预热助燃空气,达到降低排烟温度,减少燃料消耗,提高加热炉热效率和高压蒸汽产量的目的。介绍了水热媒技术的原理、特点、工艺流程以及装置实际应用中的运行步骤、注意事项和改进措施。运行结果表明,水热媒余热回收系统能够适应加热炉负荷和燃料性质的变化,排烟温度调节灵活;混合排烟温度和助燃空气温度达到了设计要求,能有效防止低温露点腐蚀,延长了设备使用寿命;加热炉群平均热效率达91.15%.节约能量为5.543MW,全年可节约燃料3812t,每年可产生经济效益1334万元。 相似文献
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本文针对常压加热炉排烟温度高,烟气余热量大等特点,采用热管和扰流子翅片管空气预热器串联使用的方法加热进炉空气,使排烟温度由350℃降到165℃,加热炉效率由80%提高到87.75%,节约燃料油853t/a。该方案为360℃以上烟气余热回收找到了一条途径。 相似文献
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一、前言 加热炉是将燃料的化学能转化成热能的主要设备。由于其排烟温度一般较高,使得热损失偏大,直接影响加热炉的热效率。为了节约燃料消耗,提高加热炉的热效率,大多数厂家对烟气余热进行了回收。随着能源的紧张,烟气余热回收已显得日趋重要。 加热炉的余热最普遍的回收方式是利用烟气余热预热助燃空气。如图1所示的空气 相似文献
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玉门炼化总厂节能潜力及节能途径分析 总被引:1,自引:0,他引:1
玉门炼化总厂拥有常减压、催化裂化、柴油加氢改质、酮苯脱蜡(脱油)、催化重整等多套装置,总加工能力达300×104t/a。由于装置加工流程长,产品加工深度大等问题,虽然实施了一些节能措施,但创新性和高技术含量的节能新技术应用较少,2008年全厂综合能耗仍高达85.33kg标油/t原料,与国内先进企业相比差距较大。为此,提出改造催化装置余热锅炉、提高加热炉热效率、开展热联合、综合优化动力系统、充分利用低温余热等节能改造方案。其中,催化装置余热锅炉采用模块化新型结构,以消除露点腐蚀,减少烟气阻力,强化传热能力,消除炉体振动,确保能量回收为主要改造目的;提高加热炉热效率主要从优选加热炉燃烧器,完善烟气热能回收、完善加热炉吹灰、降低散热损失以及调整工艺流程等方面入手。同时,应实现装置间的能量集成优化,采取热电联产工艺,减少低温热能耗损失。预计上述节能改造实施后,全厂综合能耗可降低11~21kg标油/t原料。 相似文献
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本文分析了JG-180/3.82-Q高炉煤气锅炉过热器超温的原因,基于高炉煤气着火、燃烧和燃尽原理,讨论了改善过热器超温的燃烧调整方式及相关措施。运行实际表明,可使过热蒸汽温度控制在450℃设计值左右。对节能减排有一定的参考价值。 相似文献
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Prominent equipment with a very high demand for fuels in refineries is the fired preheater of crude oil. There are two main reasons to investigate the energy usage of such fired heaters. First, this is essential to the economic value of the refinery process unit and second, this is located at the beginning of the process line, which causes inefficient performance or damage in downstream equipment if it is not tuned properly. This paper concentrates on the thermal modeling of a fired heater of crude oil to evaluate the effect of influential parameters on fuel consumption. As the number of variables is markedly high, and considering the complexity of thermal modeling, all equations in a code yield predefined heater efficiency. Results from the model show that the increase in heater size yields a decrease in efficiency. It was also found that with a constant dimension of the fired heater, change in the number of pipes is much less influential rather than more inexpensive ideas like increasing speed of the burning gas on reduction of the fuel consumption. In other words, it was found that a distance of 500–650 mm from the center to the center distance of the pipes is the optimal distance to reduce fuel consumption. 相似文献
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Kyudae Hwang Chan ho Song Kiyoshi Saito Sunao Kawai 《Applied Thermal Engineering》2010,30(17-18):2730-2737
In general, latent heat recovery is usually accompanied by the corrosion of the heat exchanger, which is caused by the strongly acidic condensate when the temperature of the flue gas is lowered below the acid dew point. The present study has been conducted to investigate the heat and mass transfer characteristics in a titanium heat exchanger with excellent corrosion resistance used for waste heat recovery with the condensation arranged in a gas fired water heater. In addition, the thermal efficiency of the gas fired water heater was evaluated based on the net calorific value at the maximum rated output during latent heat recovery from the exhaust flue gas. Parametric studies were conducted for the flue gas flow rate, inlet temperature and mass flow rate of the supplied water, respectively. Different arrangements of the tubes of the heat exchanger including in-line and staggered configurations were investigated. The experimental results indicate that the thermal efficiency of the gas fired water heater with a latent heat recovery (LHR) heat exchanger was enhanced by about 10% compared with conventional instantaneous water heaters, i.e., water heaters without heat recovery. In addition, in terms of the Nusselt number and the Sherwood number, the heat and mass transfer performance of the staggered tube bank type were approximately 50% and 10% higher than that on the in-line tube bank type when the Reynolds number of the flue gas was 103. 相似文献
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Direct fired heaters are used considerably in the energy related industries and petroleum industries for heating crude oil in the petroleum refining and petrochemical sectors. The aim of the current study is to formulate simple-to-use correlations to design the radiant and convective sections of direct fired heaters. The developed tools are easier than currently available models and involves a fewer number of parameters, requiring less complicated and shorter computations. Firstly, a simple correlation is developed to provide an accurate and rapid prediction of the absorbed heat in the radiant section of a fired heater, expressed as a fraction of the total net heat liberation, in terms of the average heat flux to the tubes, the arrangement of the tubes (circumferential), and the air to fuel mass ratio. Secondly, another simple correlation is developed to approximate external heat transfer coefficients for 75, 100, and 150 mm nominal pipe size (NPS) steel pipes arranged in staggered rows and surrounded by combustion gases. Finally, a simple correlation is presented to predict the gross thermal efficiency as a function of percent excess air and stack gas temperature. This study shows that the proposed method has a good agreement with the available reliable data in the literature. The average absolute deviations between reported data and the proposed correlations are found to be around 1.5% demonstrating the excellent performance of proposed predictive tool. The proposed simple-to-use method can be of significant practical value for the engineers and scientists to have a quick check on the design of radiant and convective sections of direct fired heater. In particular, mechanical and process engineers would find the proposed approach to be user-friendly involving no complex expressions with transparent and easy to understand calculations. 相似文献
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对天然气加热器进行了台架试验。因气态燃料极易与空气混合燃烧,故不易在热交换器内壁产生积炭和烟灰,其热效率比燃油加热器高10%以上。为了消除高温燃气因流动短路而造成的热损失,尝试了在热交换器肋片出口端面增加燃气均流环并进行了试验。另外,为了削弱热辐射及传导所造成的热能流短路损失,还做了在燃烧室外加装遮热筒试验,其试验效果显著。 相似文献
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This paper is concerned with thermohydraulic investigations on a packed bed solar air heater having its duct packed with blackened wire screen matrices of different geometrical parameters (wire diameter and pitch). The thermohydraulic performance of an air heater in terms of effective efficiency is determined on the basis of actual thermal energy gain subtracted by the primary energy required to generate power needed for pumping air through the packed bed. Based on energy transfer mechanism in the bed, a mathematical model is developed to compute effective efficiency. A design criterion is also suggested to select a matrix for packing the air flow duct of a solar air heater which results in the best thermal efficiency with minimum pumping power penalty. Resulting values of effective efficiency clearly indicate that the packed bed solar air heater investigated is thermohydraulically efficient as compared to flat plate collectors. 相似文献
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Waste heat recovery (WHR) is crucial to the efficiency improvement of natural gas‐fired boiler systems. Two‐stage WHR systems based on the natural gas‐fired boiler were analyzed from the viewpoints of thermal efficiency and heat transfer irreversibility. An overall entransy dissipation‐based thermal resistance was derived to evaluate the irreversibility of WHR, including the entransy dissipations during condensation and in absorption heat pump (AHP). Compared with the basic WHR system, the two‐stage WHR systems have higher boiler efficiency and less irreversibility. The air‐humidified system recycles both the heat and vapor in flue gas, while the unutilized latent heat in the recovered vapor causes the boiler to be less efficient than the AHP system. Investigation on heat exchanger effectiveness of two‐stage WHR systems illustrated: in the two‐stage WHR system with air humidification, the increasing effectiveness of both heat exchangers could effectively increase boiler efficiency and reduce heat transfer irreversibility. In the two‐stage WHR system with AHP, boiler efficiency has a local optimum when the dew point occurs near the outlet of the first heat exchanger; increasing the second heat exchanger effectiveness is more efficient in improving boiler efficiency. The present work may provide available references and guidance for the design and optimization of the two‐stage WHR systems. 相似文献