北京燃气锅炉排烟热损失的剖析与合理利用

对北京现已投运的燃用天然气锅炉普遍存在排烟温度偏高，造成能源浪费的原因进行分析。并对北京天然气成分分析判断，燃气锅炉排烟温度完全可以降低接近露点；测算锅炉热损失的可利用值；并介绍节省能源的可行技术及社会经济效益。     

锅炉燃烧优化调整成效显著

我厂7、8号锅炉是哈尔滨锅炉厂生产的型号为HG-1060/17.5-HM35亚临界自燃循环汽包炉。7、8号炉自投产以来一直存在着排烟温度高、水冷壁结渣和减温水量大等问题。为了分析锅炉存在上述问题的原因,在现有设备状态下在运行方式上挖掘潜力,获得适合机组运行的最佳运行方式,我们进行了多次锅炉燃烧优化调整试验。经过详细测试,锅炉排烟温度偏高设计值18℃。过热汽减温水量偏高设计值70T/H左右,再热汽减温水量偏高设计值20T/H左右。造成锅炉排烟温度偏高的原因有三方面,炉底漏风、受热面沾污和空预器换热能力差,其中空预器换热能力差应该是主要原因。造成锅炉过、再热汽减温水量大的原因有三方面,炉底漏风、水冷壁结渣和过热器受热面设计不合理,其中过热器受热面布置过多应该是主要原因。如何针对以上影响因素,彻底解决我厂7、8号锅炉排烟温度高、水冷壁结渣和减温水量大等问题,成为摆在我们面前的当务之急。     

670t/h褐煤锅炉燃烧调整试验分析及优化运行

针对大庆油田热电厂#2锅炉运行中锅炉排烟温度,灰渣、飞灰含碳量偏高,从而导致锅炉效率有所下降。为了提高锅炉运行经济性,找到影响锅炉效率的主要因素,寻求合理的运行方式,对#2炉的锅炉排烟温度、锅炉排烟氧量进行了标定,对灰渣成分进行测试,同时进行制粉系统优化调整、煤粉细度调整、磨煤机出口温度调节、二次风挡板优化调整、锅炉变氧量等单因素的优化调整及测量,分析五种因素下对锅炉效率的影响,并给出了在锅炉额定工况下的优化运行方式。     

吸收式制冷机的新型节能循环设计研究

针对双效溴化锂吸收式制冷机串联系统高压发生器排烟温度偏高，存在一定的余热资源浪费这一实际问题，采用并联增加一个低压发生器的方法，对原有系统进行改进，形成的一个新型循环系统。对该新型系统的工作原理及循环流程进行了介绍；就第二低压发生器排烟温度分别为160℃，140℃，120℃和不增设第二低压发生器这四种情况对机组进行设计研究，得出相应排烟温度下机组的制冷量、热力系数和各换热设备的换热面积及外形尺寸，并绘制出排烟温度与制冷量、热力系数及机组总换热面积之间的关系曲线，研究结果对于溴化锂吸收式制冷机的设计有一定的参考价值。     

300MW燃煤锅炉节能优化改造

本文所研究的主要内容是某电厂#1号机组供电煤耗偏高问题,特此对该机组进行全面的优化改造,锅炉侧的改造项目包括锅炉本体及管道保温治理,低NOx燃烧系统改造,空气预热器密封改造等。改造后试验数据表明,此次优化改造效果显著,锅炉排烟温度较改造前平均下降幅度可达6.56℃,使得锅炉排烟热损失大幅下降,从而使得锅炉效率明显提高。     

锅炉排烟温度升高的原因及对策

本文对排烟温度升高的各种原因进行了分析,找到了引起排烟温度升高的因素,并提出了一些切实可行的措施,为锅炉设计和设备改造治理、降低排烟温度提供参考。     

浅谈电厂锅炉排烟温度过高的原因及控制对策

本文分析了电厂锅炉排烟温度过高的主要原因，阐述了控制电厂锅炉排烟温度的有效措施，提出了降低电厂锅炉排烟温度的管理对策。     

地铁隧道火灾双点排烟烟气温度分布特性的试验研究

基于1:20的模型试验,研究了火源热释放率、排烟量和风口长度对地铁隧道火灾双点排烟烟气温度分布特性的影响。结果表明:火源段烟气温度随着火源热释放率的增加而显著增加,在排烟作用下非火源段烟气温度急剧下降;排烟量和风口长度对火源段烟气温度几乎没有影响;排烟量对非火源段烟气温度影响较大,而风口长度对非火源段烟气温度影响不大。     

浅析锅炉排烟温度高的原因及解决措施

锅炉是最为常用的热工设备,降低锅炉排烟温度对锅炉的安全经济运行及节能降耗有重要的意义,针对其排烟温度过高,导致结焦、热效率偏低的问题展开研究。本文分析了锅炉排烟温度高的原因与解决措施。     

更换余热锅炉过热器降低装置能耗

大庆石化公司100×10^4t／a重油催化裂化装置由于原设计方面原因,省煤器存在腐蚀隐患：余热锅炉排烟温度偏高,余热锅炉过热能力不足等缺陷。对余热锅炉进行改造后,装置外取热器和油浆蒸汽发生器所产的饱和蒸汽全部进行过热,提高了装置对再生烟气余热的利用率,降低了装置的能耗。     

An investigation of the treatment of particulate matter from gasoline engine exhaust using non-thermal plasma

A plasma reactor with catalysts was used to treat exhaust gas from a gasoline engine in order to decrease particulate matter (PM) emissions. The effect of non-thermal plasma (NTP) of the dielectric discharges on the removal of PM from the exhaust gas was investigated experimentally. The removal efficiency of PM was based on the concentration difference in PM for particle diameters ranging from 0.3 to 5.0 microm as measured by a particle counter. Several factors affecting PM conversion, including the density of plasma energy, reaction temperature, flow rate of exhaust gas, were investigated in the experiment. The results indicate that PM removal efficiency ranged approximately from 25 to 57% and increased with increasing energy input in the reactor, reaction temperature and residence time of the exhaust gas in the reactor. Enhanced removal of the PM was achieved by filling the discharge gap of the reactor with Cu-ZSM-5 catalyst pellets. In addition, the removal of unburned hydrocarbons was studied. Finally, available approaches for PM conversion were analyzed involving the interactions between discharge and catalytic reactions.     

Effect of EGR on the exhaust gas temperature and exhaust opacity in compression ignition engines

In diesel engines, NOx formation is a highly temperature-dependent phenomenon and takes place when the temperature in the combustion chamber exceeds 2000 K. Therefore, in order to reduce NOx emissions in the exhaust, it is necessary to keep peak combustion temperatures under control. One simple way of reducing the NOx emission of a diesel engine is by late injection of fuel into the combustion chamber. This technique is effective but increases fuel consumption by 10–15%, which necessitates the use of more effective NOx reduction techniques like exhaust gas recirculation (EGR). Re-circulating part of the exhaust gas helps in reducing NOx, but appreciable paniculate emissions are observed at high loads, hence there is a trade-off between NOx and smoke emission. To get maximum benefit from this trade-off, a paniculate trap may be used to reduce the amount of unburnt particulates in EGR, which in turn reduce the paniculate emission also. An experimental investigation was conducted to observe the effect of exhaust gas re-circulation on the exhaust gas temperatures and exhaust opacity. The experimental setup for the proposed experiments was developed on a two-cylinder, direct injection, air-cooled, compression ignition engine. A matrix of experiments was conducted for observing the effect of different quantities of EGR on exhaust gas temperatures and opacity     

通用小型汽油机进排气系统流通特性与排放性能研究

欧美国家对通用小型汽油机排放法规不断加严,目前中国生产的不同批次通用小型汽油机排放性能差异较大已是行业共有的技术难题.油气混合气浓度对通用小型汽油机排放影响很大,利用作者开发的通用小型汽油机进排气系统稳流试验台,对不同汽油机气缸盖进排气道、空滤器等进行稳流试验,对试验数据进行分析,得出进排气系统流通特性的差异和不同批次的生产波动是批量生产小型汽油机混合气浓度改变和排放性能差异的主要原因.研究结果还表明：通用小型汽油机采用压铸气缸盖,进排气道结构受压铸工艺的限制,流通系数偏低,影响发动机性能的提高,进一步提高进排气系统性能是优化通用小型汽油机性能的一个重要途径.     

离心氮压机级间排气温度偏高的分析和排除

安钢制氧厂的C180M×3N2型和C150M×5N2型氮压机运行时存在级间排气温度偏高的现象,采取加固门形垫和优化在线清洗方法清洗后,级间排气温度正常。简介离心氮压机级间排气温度高的现象,介绍引起级间排气温度高的常见原因和处理方法,阐述处理效果和保证离心氮压机级间冷却器正常运行的其他措施。     

Cyclic oxidation resistance of ferritic stainless steels used in mufflers of automobiles

This work investigates the cyclic oxidation resistance of AISI 439 and AISI 441 ferritic stainless steels (FSS) at a typical temperature of muffler (300 °C). This temperature is characteristic of the cold exhaust of an automobile. The oxidation testing of steels was performed in synthetic air in a tube furnace under two different conditions: after immersing in the synthetic condensed (TOC) for 10 h and without immersion in the synthetic condensed (TOP). The mass gain of AISI 439 steel without previous immersion in condensate was the half of the mass gain of AISI 439 steel oxidized after immersion in condensate. In all samples, the Fe₂O₃ was only identified in the oxide layer on samples that oxidized after immersion in a condensate solution. The corrosion perforation of mufflers is mostly attributed to the cyclic and synergetic effect of oxidation and condensation processes of hot moisture-bearing exhaust gas.     

Adaptive Pulse Repetition Frequency Technique for an Ultrasonic Transit-Time Gas Flowmeter for Hot Pulsating Gases

A technique of using an adaptive pulse repetition frequency (PRF) to operate an ultrasonic contrapropagation transit-time gas flowmeter (UFM) is introduced. This adaptive PRF technique allows transient measurements of hot (up to 450$^circhboxC$) and pulsating (up to 1.5 kHz) gas flows. Such conditions occur in the exhaust gas of a combustion engine. Here, a UFM with the widely used fixed PRF technique is not applicable, because the large gas temperature variations would prevent a reliable detection of ultrasonic pulse arrival times. Coherently reflected waves are generated within the gas because of the unavoidable acoustic impedance mismatch between the gas and the transducers, and, depending on the gas temperatures, these echoes overlap with the main signal. The adaptive PRF technique overcomes this problem and allows correct pulse detection over the whole temperature range required. The UFM utilizes special high-temperature-resistant capacitance ultrasonic transducers (CUTs) to meet the requirements in terms of operating temperature range and dynamic response. Results, which are obtained with a preliminary laboratory prototype, are presented for the exhaust gas mass flow rate in a$varnothing$50-mm pipe measured at gas temperatures of up to 450$^circhboxC$and at PRFs of up to 5.5 kHz, which is an increase in frequency response of one order of magnitude in comparison to existing measurement systems.     

Investigation of an ammonia-water combined power and cooling system driven by the jacket water and exhaust gas heat of an internal combustion engine

An ammonia-water combined power and cooling system is proposed and investigated in this work, in which the waste heat contained in the jacket water and exhaust gas of an internal combustion engine can be recovered efficiently to generate power and cooling energy simultaneously. The proposed system was simulated, and its thermodynamic performance in the base case was calculated based on waste heat data from an actual gas engine with a rated power output of 300 kW. The equivalent heat-to-power efficiency of the combined system is 19.76%, and the total equivalent power output is as high as 92.86 kW. The exergy efficiency of the combined system reaches 33.69%. The effects of the turbine inlet pressure, generation pressure in the reboiler, exhaust gas temperature and cooling water temperature were studied to provide guidance for the system design. The results of an economic analysis indicate that the proposed system has good economic benefit.     

燃煤机组“消白”技术排烟温度的理论分析

燃煤机组湿法脱硫后,产生的湿烟气由烟囱排入温度较低的环境中会遇冷凝结,即冒“白烟”现象。建立了燃煤机组各“消白”技术的排烟温度的理论计算模型,并以西安、石家庄、上海地区为例计算研究不同地区“消白”技术的特点。结果表明,环境温度较高时,烟气直接加热法可有效消除白烟;环境温度低时,烟气降温再热法可以更有效地消除白烟。春夏季可以采用直接加热法消除白烟,排放烟温根据环境因素应控制在60~75℃;在秋冬季,当环境温度在9℃、相对湿度为60%以下时,建议采用降温再热法消除白烟,秋季可先降到45℃再加热到75℃排放,冬季可先降到45℃再加热至85℃排放。     

应对欧V排放检测标准相关气体标准物质的研制

主要叙述了为应对欧V排放检测标准所使用的氮中一氧化碳、氮中一氧化氮和氮中丙烷气体标准物质的研制方法,同时描述了用气相色谱仪和氮氧化物分析仪对配制的氮中一氧化碳、丙烷、一氧化氮三种标准物质进行浓度检测的过程,并介绍了进行均匀性、稳定性考察的方法,保证测定数据准确可靠。配制的氮中一氧化碳、氮中丙烷气体标准物质浓度分别为1．00μmol／mol,不确定度3％。氮中一氧化氮浓度为（1．00—25．0）μmol／mol,不确定度6％。     

Flow Visualization in a Rotating-Arc Plasma Jet

Knowledge of the gas flow pattern in a plasma jet exhaust is important in relation to heat transfer and gas temperature estimation. The extreme conditions within the jet, however, have hitherto encouraged the use of water cooled probes for flow measurements to the exclusion of quicker and more convenient optical methods.

An optical system has been developed to indicate gas velocities throughout the volume of a transparent water jacket enclosing the exhaust gas by means of particle track photography. The difficulties caused by the size of the test space and the high gas luminosity are overcome by using a bi-focal lens system to utilize a photographic flash bulb source efficiently.