新建炼厂设计阶段提高加热炉热效率的措施

在炼油加工过程中,加热炉是能耗大户.对新建炼厂,在设计阶段提高加热炉热效率,对节能减排有重要意义.在设计过程中,采取燃料气脱硫等措施以降低排烟温度、降低空气过刹系数和漏风量等措施以降低过剩空气量、优化设计加热炉衬里以降低散热损失、优化余热回收系统方案和控制方案以提高烟气余热利用率和操作稳定性、利用装置废热预热助燃空气,...     

无机高效传热技术在原油处理设备中的应用

无机传热元件具有启动迅速、导热系数高及均温性好等优良的传热特性。本文首次将无机传热元件应用于油气田高效加热炉,使设计热效率达到92％,钢耗量由平均13t／MW下降到6-8t／MW,设备造价降低15％,并首次将无机高效传热元件应用于原油处理设备,较好地解决了传统设备由于采用火筒直接加热油井产物所导致的结焦、爆管问题,提高了设备的使用寿命和安全可靠性,并使热负荷减少50％以上,燃气量减少50％以上。利用该技术开发出的两种无机传热高效原油处理设备,对油田地面工程建设及生产运行中的节能降耗具有参考意义。     

Novel predictive tools for design of radiant and convective sections of direct fired heaters

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.     

Effect of geometrical parameters on thermal efficiency and fuel consumption of heaters of a natural gas pressure reduction station using Sobol statistical sensitivity analysis

The main objective of natural gas pressure reduction station or city gate stations (CGSs) is to adjust gas pressure within a standard range for home usage. CGSs usually utilize heaters for pressure tuning, which generally consume a considerable amount of energy. In this paper, the effect of six influential parameters, namely, the length of gas-coil, the diameter of gas-coil, the radius of heater shell, length of heater shell, fire tube diameter, and length, on the amount of fuel consumption and thermal efficiency is investigated using Sobol statistical sensitivity analysis. The results show that gas-coil length and diameter are not effective in fuel consumption and thermal efficiency. In contrast, increasing the heater shell radius, heater shell length, and fire tube radius has the same effect as they cause a linear increase in fuel consumption. According to results taken from Sobol analysis, they similarly have an influence of 19%–23% on fuel consumption and 21%–22% on thermal efficiency. Finally, it was revealed that the effect of fire tube length on fuel consumption and thermal efficiency of the heater was 37% and 35%, respectively.     

The performance analysis and evaluation of C‐PV/T aided power generation system

In this paper, a novel solar aided power generation (SAPG) hybrid system based on the structural characteristics of coal‐fired power generation is established. In this system, the extraction steam of No.8 low pressure heater is replaced by the hot water coming from a concentration‐photovoltaic/thermal (C‐PV/T) module. The extraction steam returns into the steam turbine to do work, which increases the output power. And the electricity from the parallel C‐PV/T module goes directly into the power grid, which increases the generated power. The C‐PV/T module coupled with coal‐fired power generation improves the solar energy efficiency and provides hot water. As a case study, the economic calculation is performed with actual operation data extracted from a 600‐MW coal‐fired unit. The results show that the total efficiency increased by 1.3%, the coal fuel consumption is lowered by 11 g/kW·h, and the investment recovery period is approximately 7 years. This study offers a theoretical support to the engineering demonstration.     

Analysis of the influence of operating conditions on fouling rates in fired heaters

Fouling due to chemical reaction in preheat trains for the processing of crude oil plays a key role in the operation and maintenance costs and on greenhouse emissions to atmosphere in crude processing plants. A preheat train consists of a set of heat transfer units that provide the crude oil stream the required amount of thermal energy to reach its target temperature either by heat recovery or by direct firing. Fired heaters supply external high temperature heating through the burning of fuel which result in complex heat transfer processes due to the large temperature and pressure changes and vaporization that takes place inside the unit. In this work, a thermo-hydraulic analysis of the performance of fired heaters is carried out through the application of commercial software to solve the mathematical models using finite difference methods; the analysis is applied to the crude side of a vertical fired heater in order to evaluate the impact of process conditions such as throughput and crude inlet temperature (CIT) on the fouling that take place at the early stages of operation. Using a fouling rate model based on thermo-hydraulic parameters, fouling rates are predicted assuming steady state operation and clean conditions. Although variations in process conditions are known to influence fouling rates, little work has been done on the subject. In this work excess air and steam injection are studied as a means to mitigate fouling. Results show that throughput reduction brings about a marked increase in the fouling rates. A decrease in CIT affects only the convection zone and it is found that this effect is negligible. In terms of excess air, it is found that although it affects negatively the heater efficiency it can be used to balance heat transfer between the convection and radiation zone in a way that fouling rates are reduced; however this strategy should be considered right from the design stage. Finally it is observed that steam injection is an effective method to reduce fouling rates since it results in lower film temperatures and larger shear stress.     

车用YJP-Q系列加热器供油系统性能初探

对车用YJP-Q系列喷射式液体燃油加热器所用供油系统进行了台架摸底试验。分析了油泵转速特性;油压特性;喷油嘴特性;油泵供、回油管长度、内径的影响;油泵距油面高度及燃油滤清器的影响。试验发现:油管过长,内径过细,会使油泵流量和容积效率下降,并使泵前真空和噪声大大上升;所用滤清器有效过滤面积偏小,原始阻力约为行业标准的2.5倍,从而导致油泵进油口真空升高,使噪音加剧。     

高效燃油/气管架式有机热载体锅炉研制

分析国内燃油/气有机热载体锅炉的主流结构及特点,进而论述了高效燃油/气管架式有机热载体锅炉的研制,并介绍其特点。     

高效燃气热水器的实验研究和节能分析

介绍了研制的新型家用燃气热水器和热水炉（兼有热水供应和采暖的功能）其特点是：冷凝传热和低污染燃烧技术。对家用燃气热水器和热水炉进行了实验研究，在不同运行工况下测定了热水器的热效率和NOx及CO的排放量，并与传统热水器进行了对比分析。实验结果表明，新型家用燃气热水器及热水炉具有高热效率和低污染排放的特点，它能大大降低对环境的污染。     

油田热采用蒸汽锅炉燃料变更的研究

油价的持续高涨,以及石油作为一种战略性资源,我国各大油田加快了稠油的开采力度.油田热采用蒸汽锅炉是稠油开采的关键设备,为了降低开采成本,各大油田提出了采用燃煤替代原有的燃油热采用锅炉,提出了解决这一问题的办法.     

水套加热炉的改进设计

采用蓄热式燃烧技术对原有的水套加热炉进行了改进设计。改进后的蓄热式水套加热炉,运行热效率可达80％以上,与原有加热炉相比,具有自动化程度高,节能效果显著的特点。     

调和剂改善车用轻油基混合燃料燃烧性能的研究

与车用汽油相比,轻油中轻质馏分较多,蒸发性好,但辛烷值低,蒸气压高、热值较低。经测试分析,确定以甲醇、酚溶剂油以及甲基叔丁基醚（MTBE）作为轻油高辛烷值调合剂,研究开发了多种轻油基混合燃料。马达法辛烷值测定及发动机台架性能试验结果表明：轻油基混合燃料辛烷值较高,火花点火式发动机燃用轻油基混合燃料时动力性稍有下降,但指示热效率和有效效率提高;混合燃料抗爆性较好,发动机可有用更高的压缩比工作,提高热效率,降低油耗。     

中国电站锅炉节能点火技术的应用与发展

由于全球能源供应的紧张,原油价格不断上涨及电厂竞价上网政策的出台,降低电厂锅炉运行成本特别是锅炉点火成本是提高火电厂发电效益的重要措施,因此开发和利用无油或少油煤粉直接点火技术,降低点火助燃用油,是当今电力行业普遍关注的课题。本文综述了当前国内火力发电厂较常用的锅炉节能点火技术,阐述了不同锅炉节能点火技术的原理、优缺点及相应的技术改造。     

Performance of jatropha oil blends in a diesel engine

Results are presented on tests on a single-cylinder direct-injection engine operating on diesel fuel, jatropha oil, and blends of diesel and jatropha oil in proportions of 97.4%/2.6%; 80%/20%; and 50%/50% by volume. The results covered a range of operating loads on the engine. Values are given for the chemical and physical properties of the fuels, brake specific fuel consumption, brake power, brake thermal efficiency, engine torque, and the concentrations of carbon monoxide, carbon dioxide and oxygen in the exhaust gases. Carbon dioxide emissions were similar for all fuels, the 97.4% diesel/2.6% jatropha fuel blend was observed to be the lower net contributor to the atmospheric level. The trend of carbon monoxide emissions was similar for the fuels but diesel fuel showed slightly lower emissions to the atmosphere. The test showed that jatropha oil could be conveniently used as a diesel substitute in a diesel engine. The test further showed increases in brake thermal efficiency, brake power and reduction of specific fuel consumption for jatropha oil and its blends with diesel generally, but the most significant conclusion from the study is that the 97.4% diesel/2.6% jatropha fuel blend produced maximum values of the brake power and brake thermal efficiency as well as minimum values of the specific fuel consumption. The 97.4%/2.6% fuel blend yielded the highest cetane number and even better engine performance than the diesel fuel suggesting that jatropha oil can be used as an ignition-accelerator additive for diesel fuel.     

Experimental study on titanium heat exchanger used in a gas fired water heater for latent heat recovery

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.     

俄罗斯原油评价数据及加工流程的优化选择

原油评价是在实验室对原油进行一系列分析和馏分切割,分析原油和各段馏分油的性质,确定产品分布及产品收率,为制定原油加工流程提供优化方案,以生产出合适的产品,使原油资源得到合理利用。原油评价认为,俄罗斯原油属于含硫中间基原油,初馏点至180℃石脑油馏分经石脑油加氢精制后,分离出液态烃、轻石脑油及重石脑油;150~230℃喷气燃料馏分进入加氢精制装置,生产3号喷气燃料或柴油调和组分;200~350℃柴油馏分进入柴油加氢精制装置,生产合格的柴油产品;350~560℃混合蜡油馏分进入加氢裂化装置,生产石脑油、高品质航空煤油(3号喷气燃料)及柴油;大于560℃渣油馏分经渣油加氢精制后,可作为催化原料直接进入重油催化裂化装置。俄罗斯原油的盐含量为24.0mg/kg,在加工过程中,容易形成"HCl-H2S-H2O"腐蚀,对设备影响较大,要重视工艺防腐和设备防腐。     

Simulation and modeling of copper-chlorine cycle,molten carbonate fuel cell alongside a heat recovery system named regenerative steam cycle and electric heater with the incorporation of PID controller in MATLAB/SIMULINK

MCFC (molten carbonate fuel cell) is a relatively new kind of fuel cell that may be utilized in both local and large-scale energy distribution and generating systems. MCFCs are largely regarded as a viable source of renewable energy. Making an MCFC is a time-consuming and costly process. Mathematical modeling and efficiency simulations are essential to appropriately maximize its performance. Regenerative cycle, copper-chlorine cycle, and electric heater with PID controller is also studied to integrate them with MCFC to increase the efficiency of the overall system. Copper–Chlorine cycle is integrated to provide a stable stream of hydrogen and oxygen for the fuel cell. The Molten Carbonate fuel cell of stack 100 generates 1.203 MW of power at Voltage of 1.2 V each. Waste Heat recovery system is installed named regenerative Steam cycle which produces 2.94 MW of power. The total efficiency of system is 57% and the total extracted power is 4.143 MW. MATLAB/Simulink R2020a is used for modeling of multigeneration system with use of Engineering Equation Solver.     

The energy efficiency of crude oil refining in Brazil: A Brazilian refinery plant case

This article evaluates energy efficiency in Brazilian crude oil refining in comparison with the crude oil refining in the United States between 1930 and 2008. It aims to show that increased refinery complexity reduces the energy consumption of products of high value added. Moreover, the article shows that improvements in energy efficiency result in higher quality products and increased processing of oil. A Brazilian refinery with a capacity of 157,000 barrels per day (kbpd) was modernized in 2008 at a cost of US $1.3 billion. As a result, its capacity increased by 17%, from 157 to 189 kbpd. Its complexity index also rose from 3.2 to 6.8, allowing an improvement in the EII (energy intensity index) from 110% to 93%. In relation to the crude oil processed before being modernized, energy consumption fell from 0.75 to 0.52 MBtu (million British thermal units) per barrel processed. These proceedings show that increases in complexity reduce the energy consumed in the production of final products with high value added, such as gasoline, diesel and jet fuel.     

水煤浆锅炉的能效分析

通过定量和定性计算分析水煤浆水分、磨煤电耗、锅炉运行热效率以及锅炉运行电耗对锅炉能效的影响,并与链条炉排锅炉和煤粉锅炉比较,指出水煤浆替代重油燃烧虽可取得明显的经济效益,但在能效方面却不及燃烧制浆原料煤的链条炉排锅炉或煤粉锅炉。     

Performance of direct-injection off-road diesel engine on rapeseed oil

This article presents the comparative bench testing results of a naturally aspirated, four stroke, four cylinder, water cooled, direct injection Diesel engine operating on Diesel fuel and cold pressed rapeseed oil. The purpose of this research is to study rapeseed oil flow through the fuelling system, the effect of oil as renewable fuel on a high speed Diesel engine performance efficiency and injector coking under various loading conditions.Test results show that when fuelling a fully loaded engine with rapeseed oil, the brake specific fuel consumption at the maximum torque and rated power is correspondingly higher by 12.2 and 12.8% than that for Diesel fuel. However, the brake thermal efficiency of both fuels does not differ greatly and its maximum values remain equal to 0.37–0.38 for Diesel fuel and 0.38–0.39 for rapeseed oil. The smoke opacity at a fully opened throttle for rapeseed oil is lower by about 27–35%, however, at the easy loads its characteristics can be affected by white coloured vapours.Oil heating to the temperature of 60 °C diminishes its viscosity to 19.5 mm² s⁻¹ ensuring a smooth oil flow through the fuel filter and reducing the brake specific energy consumption at light loads by 11.7–7.4%. Further heating to the temperature of 90 °C offers no advantages in terms of performance. Special tests conducted with modified fuel injection pump revealed that coking of the injector nozzles depends on the engine performance mode. The first and second injector nozzles that operated on pure oil were more coated by carbonaceous deposits than control injector nozzles that operated simultaneously on Diesel fuel.