燃气锅炉烟气潜热势利用技术研究

为进一步提高燃气锅炉热效率,同时兼顾低氮燃烧技术的应用,研发了一种烟气潜热回收与低氮燃烧耦合技术,并对1台7 MW燃气热水锅炉实施改造,通过实测对比分析改造前后锅炉能效和NO_x排放的变化。结果表明:改造后烟气潜热回收率提高,锅炉热效率升至102.7%,提高了6.2%;其中,锅炉本体和省煤器结算热分别提高1.3%和5.5%,散热损失增加0.6%。NO_x排放浓度与助燃空气含湿量有关,随助燃空气含湿量升高显著降低,当助燃空气含湿量为116.6 g/kg时,NO_x排放浓度可低至19 mg/m~3;改造后锅炉单位热产品NO_x减排率达80%以上,环境效益显著。     

天然气掺氢对家用燃气灶燃烧特性的影响研究

为了研究天然气掺氢后对家用燃气灶燃烧特性的影响,文章通过燃气互换性理论确定了天然气的最大掺氢比例为23%,在此基础上设置灶前压力分别为1 500,2 000,3 000 Pa,并对掺氢比例分别为5%,10%,15%,20%的天然气进行燃烧试验。试验结果表明:随着天然气掺氢比例的增加,家用燃气灶的一次空气系数逐渐增加,热负荷逐渐下降,热效率逐渐升高;天然气掺氢后,家用燃气灶烟气中的CO,NO,NO_x含量均低于纯天然气燃烧后的烟气。     

蓄热式燃烧技术在冷凝式燃气锅炉上的应用

天然气等碳氢燃料燃烧后的烟气中合有大量水蒸气,将排烟温度降低到水蒸气冷凝温度以下可回收水蒸气的冷凝潜热,锅炉热效率按低位发热量计算可超过100％.热平衡计算结果显示可以用助燃空气回收烟气的冷凝潜热,但烟气进口温度有一个上限值.将蓄热式燃烧技术用于燃气锅炉,可将烟气温度降低到冷凝温度之下.换向周期越短热效率越高,换向周期20 s时热效率可达106.7％.通过空气分级燃烧可以使烟气中NOx排放水平降低到46 mg/m3 (6％O2)左右的水平,且烟气冷凝液可吸附烟气中约14.3％的NOx.     

提高助燃风温度对熔铝炉燃烧特性影响的研究

回收熔铝炉排烟热量加热助燃风可以提高熔铝炉热效率。为了深入研究提高助燃风温度对熔铝炉燃烧的影响,首先通过对天然气理论燃烧温度、火焰长度、烧嘴燃烧能力等方面进行理论计算分析,得到不同助燃风温度对熔铝炉燃烧特性的影响变化趋势。然后根据助燃风压力对烧嘴燃烧能力的影响,分析并得到不同助燃风下满足烧嘴燃烧能力的最优助燃风压力。最后通过具体实例分析证明:在不改变烧嘴的前提下,回收熔铝炉烟气余热可以提高助燃风温度,还可以提高熔铝炉热效率及熔铝速度。     

鼓风式灶用燃烧器燃料与助燃风适配性研究

标定了鼓风式燃气灶助燃风机进口挡板在不同位置时的风量和压头,并计算出相应位置所需的燃气量,使得燃气灶在不同功率负荷下助燃风量和燃料量的匹配得到优化,以提高其热效率并降低污染物排放量。     

应用于燃油锅炉的富氧空气助燃技术探讨

介绍富氧助燃技术,并论述该技术应用于燃油锅炉的节能减排效果。通过对燃烧过程进行热工分析得知,采用含氧浓度为28%的富氧空气进行助燃时,烟气排放明显减少,燃烧室理论温度可由1340K左右提高至1720K以上。在富氧空气气氛下,柴油燃烧速度也有一定提高。以常见的系统工艺及实际情况为例,对富氧空气助燃的经济可行性加以论述,并初步提出了技术改进方案。结果显示,采用富氧空气助燃技术可以达到节约能源、降低排放的效果。     

燃气灶的节能研究

该文阐述了家用燃气灶节能的四条新途径。即湍流燃烧，将敞开燃烧改变为半封闭燃烧，增大高温火焰换热面积和复合结构的节能装置设计，试验证明，在家用燃气灶上应用节能装置，能够显著提高热效率，节省燃气，达到节能清洁燃烧。     

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,...     

高效回收锅炉烟气热能装置

回收锅炉烟气热量,预热助燃空气,改善燃料的着火和燃烧条件,降低排烟温度,是提高锅炉热效率的重要途径。本文从回收系统及应用,参数计算和技术经济效果等方面系统地介绍了利用回转再生式热交换器(以下简称热交换器)回收锅炉烟气热能装置,以使它在低秒锅炉的技术改造中发挥作用。     

加热炉空气预热器最佳设计

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     

燃气隧道窑热工测试与节能分析

我国工业炉窑是能耗大户,总体水平较低,具有相当大的节能潜力。以某高铝砖隧道窑为测试对象进行了详细的热工测试,测量了炉气温度、烟气参数、干燥段的气流参数以及各主要壁面的温度,通过计算窑车及物料带出的热量、干燥段排气热损失、排烟热损失和壁面散热损失等参数,对隧道窑进行了热平衡分析。结果表明,所测试隧道窑的热效率为33.4%,造成热损失的原因包括,砖坯码放方式、干燥段气流组织不合理、助燃空气量过大、围护结构保温性能差等,通过改善急冷段和干燥段气流组织,减小预混空气量,增强窑顶和烧成段保温等措施可实现该类隧道窑的节能。     

应用溴化锂吸收式制冷技术提高燃气轮机电站发电效率的研究

对燃气轮机进口的空气进行预冷,能够提高发电机组的输出功率。与蓄冷方法相比,使用燃气轮机－蒸汽联合循环电站余热锅炉低压蒸发器的一部分蒸汽为热源,利用溴化锂吸收式制冷机制取冷源,冷却燃气轮机进口处的空气,以提高发电机组的输出功率,该方法技术可行,经济效益显著。     

Development of a high efficiency radiation converter using a spiral heat exchanger

Heating by radiation is widely used for materials processing. Electrical radiant heaters are the most commonly used heaters. Electricity is expensive and the combustion of fossils fuels for electricity production emits CO₂. In order to convert the energy from the fuel to radiation energy directly and efficiently, our group has developed a compact, high efficiency, radiation converter using a spiral heat exchanger to recover the energy from high-temperature exhaust gas. The spiral heat exchanger has a weld-free construction to prevent cyclic thermal stress, and is constructed from inexpensive ferrite steel plates. The combustion chamber, equipped with a swirler to mix the gas fuel and air, can achieve stable combustion. The distribution of the surface temperature on the radiant tube was measured by a radiation thermometer, called a thermo viewer, and then the radiant energy emitted from the radiant tube was estimated. The efficiency of the spiral heat exchanger was measured from the temperature of the inlet air and exhaust gas. The heat exchanger achieved a high effectiveness, and heat loss from the exhaust gas was minimized. Consequently, a highly efficient radiation converter was produced to convert the fuel energy to radiation energy.     

炼油装置加热炉节能途径与制约因素

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。     

天然气热利用率及影响因素

用热力学理论和燃烧理论建立了天然气排烟温度与热利用率的计算模型,计算得出了天然气热利用率与排烟温度的关系曲线,可供实际工程参考.对影响天然气热利用率的因素(排烟温度、过剩空气系数和烟气冷凝温度)的主要影响因素(燃烧空气含湿量)进行了定量分析,提出了提高天然气热利用率的措施,可使天然气的热利用效率提高1000/~2000/.     

Development and test of combustion chamber for Stirling engine heated by natural gas

The combustion chamber is an important component for the Stifling engine heated by natural gas. In the paper, we develop a combustion chamber for the Stifling engine which aims to generate 3-5 kWe electric power. The combustion chamber includes three main components： combustion module, heat exchange cavity and thermal head. Its feature is that the structure can divide ＂combustion＂ process and ＂heat transfer＂ process into two appar- ent individual steps and make them happen one by one. Since natural gas can mix with air fully before burning, the combustion process can be easily completed without the second wind. The flame can avoid contacting the thermal head of Stifling engine, and the temperature fields can be easily controlled. The designed combustion chamber is manufactured and its performance is tested by an experiment which includes two steps. The experi- mental result of the first step proves that the mixture of air and natural gas can be easily ignited and the flame burns stably. In the second step of experiment, the combustion heat flux can reach 20 kW, and the energy utiliza- tion efficiency of thermal head has exceeded 0.5. These test results show that the thermal performance of com- bustion chamber has reached the design goal, The designed combustion chamber can be applied to a real Stifling engine heated by natural gas which is to generate 3-5 kWe electric power.     

Theory and performance analysis of a new heat engine for concentrating solar power

The objectives of this paper are to introduce a new heat engine and evaluate its performance. The new heat engine uses a gas, such as air, nitrogen, or argon, as the working fluid and extracts thermal energy from a heat source as the energy input. The new heat engine may find extensive applications in renewable energy industries, such as concentrating solar power (CSP). Additionally, the heat engine may be employed to recover energy from exhaust streams of internal combustion engines, gas turbine engines, and various industrial processes. It may also work as a thermal‐to‐mechanical conversion system in a nuclear power plant and function as an external combustion engine in which the heat source is the combustion gas from an external combustion chamber. The heat engine is to mimic the performance of an air‐standard Otto cycle. This is achieved by drastically increasing the time duration of heat acquisition from the heat source in conjunction with the timing of the heat acquisition and a large heat transfer surface area. Performance simulations show that the new heat engine can potentially attain a thermal efficiency above 50% and a power output above 100 kW under open‐cycle operation. Additionally, the heat engine could significantly reduce CSP costs and operate in open cycles, effectively removing the difficulties of dry cooling requirement for CSP applications. Copyright © 2014 John Wiley & Sons, Ltd.     

多孔介质回热微燃烧器的扩散燃烧

设计了多孔介质回热微燃烧器.进行了微燃烧器的扩散燃烧特性实验研究,得到了其燃烧效率、出口尾气温度、壁面温度和热损失率随燃烧热功率和过量空气系数的变化规律.实验发现,在较宽的操作范围内,微燃烧器具有较高的燃烧效率和出口尾气温度,而且随着燃烧功率和过量空气系数的增大,微燃烧器的壁面温度和热损失率反而减小.分析表明,采用回热夹层和多孔介质相向的进气方式,使得反应气体的流动方向与散热方向相反,有效回收了热量损失,提高了微燃烧器的热效率和出口尾气温度.所设计的多孔介质回热微燃烧器对开发微燃烧透平发电系统具有重要应用价值.     

Combustion characteristics and energy recovery of a small mass burn incinerator

The burning characteristics and energy recovery of a small mass burn incinerator, which is featured by a Cyclone Heat Recovery System (CHRS), are investigated experimentally. The burning behaviors of two combustion chambers are analyzed by observing the variations of temperature that are monitored by thermocouples. On the other hand, hot flue gas and cool water respectively passing through the cyclone inside and outside implements and energy recovery. As the result, it demonstrates that there is a drastic interaction between the two chambers' combustion, resulting from the sensitivity of wastes burning on charging period. In particular, when the charging period is large to some extent, combustion instability in the secondary chamber is exhibited obviously. With regard to the cyclone, the obtained results indicate that the efficiencies of heat exchange and heat recovery are in the ranges of 65% to 75% and 15% to 20%, respectively. The above result reveals that the efficiency of energy recovery from the CHRS is not very high. However, this designed system simultaneously covers the merits of conservation of energy resource, air pollution control, as well as corrosion and erosion prevention.     

等温压缩空气储能系统液气传热特性研究

等温压缩空气储能（I CAES）无需补燃、能源利用率高且碳排放低,在大规模储能领域具有重要应用前景。在建立喷雾的I CAES系统的液气传热模型基础上,通过数值方法分析了喷雾流量对I CAES液气传热特性的影响规律。结果表明：采用喷雾方法能够有效抑制压缩和膨胀过程的温度变化、强化液气传热并实现理想I CAES过程;增大喷雾流量能够降低压缩功耗、提高膨胀做功并降低停机储气过程压损,可提高系统指示效率和储能效率。