新型Rijke管燃烧装置特性分析

在实验的基础上指出,声脉动的发生不仅取决于Ｒｉｊｋｅ燃烧器的结构及热源位置,还受到进口处空气流速、温度梯度和气体平均密度等参数的影响。当这些参数和脉动速度数量级相当时,稳定的声场强度随空气进口流速的增大而加强,该流速的确定同时还要考虑燃烧的完全性。维持一个稳定的声波作用工况必须满足对热源强度与位置特性的要求以及燃烧器进口空气流场分布均匀性的要求。     

太阳能增强型喷射式制冷系统的研究

对太阳能为热源的增强型喷射式制冷系统进行了热力学分析，并进行了初步实验。在９０℃热源、１２℃蒸发温度和２０００Ｗ制冷量的额定工况下，喷射系数可达０．６５１，整个系统的ＣＯＰ值达０．３３４，比传统的纯喷射制冷循环的ＣＯＰ值（≤０．２３）提高５０％。     

应用微压探测诊断燃烧状况的试验研究

利用压力传感器进行了燃烧状态诊断的试验研究。提出了一种通过压力脉动信号分析燃烧状态的简单有效方法，该方法对归一化后压力脉动信号作线性回归并计算回归直线斜率Ｋ，根据Ｋ值对燃烧状态进行分类判断。研究发现，随Ｋ值的增大燃烧状态趋于不稳定，对于本实验炉当│Ｋ│〉０．６时为燃烧状态处于的熄火和点火剧变过程，而│Ｋ│∈「０．３，０．６」则燃烧处于不稳定状态，只有│Ｋ│〈０．１５时燃烧状态才基本稳定。     

火花点火发动机压力循环变动特性研究

作由连续循环的压力示功图求出各循环的平均指示压力及燃烧百分率，取得了平均指示压力变动率随转速，负荷，空燃比，点火提前角的变化曲线。并分析了从火花跳火到燃烧百分率为０．１，０．５，０．９时曲轴所转过角度之间的自相关系数。最后还研究了平均指标压力同从点火到燃烧百分率为０．１，０．５，０．９时曲轴转过角度之间的自相关系数。     

用流化床焚烧造纸污泥的热态试验

在一床截面积为 ０．２３×０．２３ｍ ２ 的流化床热态试验台上,在无辅助燃料助燃的情况下,对影响造纸污泥稳定燃烧的各种因素进行了研究。试验表明当水份不大于 ５０％ 时,能稳定燃烧。     

流化床飞灰回送再燃试验研究

本文总结了无烟煤在有飞灰回送的流化床上燃烧实验结果。由于采用了细灰循环再燃烧技术，很大地提高了其燃烧效率。针对ＱＹＤＷ＝４０００ｋｃａｌ／ｋｇ的京西无烟煤，在床温９４５℃～９８０℃的条件下，循环倍率Ｒ从０增加到１．９时，燃烧效率从５９．５７％提高到９３．３３％。试验还表明，增加床温、气速都可提高燃烧效率。试验研究在床面积２８５×２８５ｍｍ￣２的流化床装置上进行，该装置的细灰循环系统由旋风除尘器，“Ｌ’型阀、喷射器和底部饲料器组成，试验验证了该系统及设备的适用性。为灰循环技术使用于循环流化床上提供了一定的参考依据。     

应用干馏煤气发生装置的"三联产"工艺探索

一种新型的三联产装置，采用循环流化床的热灰作为干馏器的热源裂解燃煤，干馏煤气作为城市煤气用，半焦送到锅炉中燃烧生产蒸汽。这种装置可充分利用劣质煤，适合我国国情。     

用流化床焚烧造纸污泥的热态试验

在一床截面积为０．２３ｍ×０．２３ｍ的流化床热态试验台上,造纸污泥在无辅助燃料助燃的情况下,对影响稳定燃烧的各种因素进行试验。试验表明当水分不大子５０％时能稳定燃烧。     

粉煤流化床燃烧（PCF—FBC）的热态试验研究

提出了一种新型高效、清洁煤燃烧方法，即粉煤流化床燃烧，并在一个热输入为０．３ＭＷ的试验装置上进行了热态试验研究。该方法全部燃用粉煤，具有粉煤燃烧高效率和流化床燃烧低污染的特点。     

等离子体化学促进燃烧装置

介绍了等离子体化学促进燃烧装置的原理、结构和它的应用．这种装置，可以用于燃烧液态、气态、固态燃料．不仅使燃料达到完全燃烧和明显降低有害物质逸入大气，而且可以提高燃烧设备的热效率，从而达到降低燃料消耗的目的．     

MICROCHANNEL COMBUSTOR EVAPORATOR THERMAL PROCESSES

This article presents the results of an experimental investigation of the performance of an integrated microchannel combustor evaporator. Separate experimental investigations were conducted on combustion in small channels and evaporation in microchannels. These results, along with the results of a simulation of heat transfer from the flue gas in microchannels, were used to design, and subsequently fabricate and test, microchannel combustor evaporators. Performance results showed that the combustor evaporator was capable of achieving high heat fluxes (up to 30 W/cm2) while maintaining a high combustor efficiency.     

斯特林发动机天然气扩散燃烧的数值分析和试验

应用数值模拟,对斯特林发动机中天然气的燃烧进行了全尺寸三维模拟。分析和优化对斯特林发动机燃烧室速度场、温度场分布以及排放有着重要影响的参数,如空气预热温度、旋流数和过量空气系数等。预测了优化后燃烧室的速度场、温度场分布,以及NO_x和CO的浓度场分布,得到了吸热部件周围的流动形式。模拟结果为抑制NOx和CO的排放和提高换热效率以及发动机的效率提供了指导,设计结果得到了试验验证。     

Flame stability and emission characteristics of propane-fueled flat-flame miniature combustor for ultra-micro gas turbines

An engineering model of a propane-fueled miniature combustor was developed for ultra-micro gas turbines. The combustion chamber had a diameter of 20 mm, height of 4 mm, and volume of 1.26 cm³. The flat-flame burning method was applied for lean-premixed propane–air combustion. To create the stagnation flow field for a specific flat-flame formation, a flat plate was set over the porous plate in the combustion chamber. A burning experiment was performed to evaluate the combustion characteristics. The flame stability limit was sufficiently wide to include the design operation conditions of an equivalence ratio of 0.55 and air mass flow rate of 0.15 g/s, and the dominant factors affecting the limit were clarified as the heat loss and velocity balance between the burning velocity and the premixture flow velocity at the porous plate. CO, total hydrocarbons (THC), and NO_x emission characteristics were established based on the burned gas temperatures in the combustion chamber and the temperature distribution in the combustor. At an air mass flow rate of less than 0.10 g/s, CO and THC emissions were more than 1000 ppm due to large heat loss. As the air mass flow rate increased, the heat loss decreased, but CO emissions remained large due to the short residence time in the combustion chamber. NO_x emission depended mainly on the burned gas temperature in the combustion chamber as well as on the residence time. To reduce emissions despite the short residence time, a platinum mesh was placed after the combustion chamber, which drastically decreased the CO emissions. The combustor performance was compared with that of other miniature combustors, and the results verified that the present combustor has suitable combustion characteristics for a UMGT, although the overall combustor size and heat loss need to be reduced.     

微热光电系统带环形翅片燃烧室的数值模拟

最大化提高微燃烧室的燃烧效率对于微热光电系统是非常关键的。建立了微燃烧室内的流动、传热和燃烧模型并进行了数值模拟。利用试验结果验证了模型的可靠性。在此基础上,模拟了带有环形翅片燃烧室的情况,表明环形翅片能增强微燃烧室内混合气体的湍流扰动,改善燃烧状况,有效地提高燃烧效率。     

Combustion and heat transfer at meso-scale with thermal recuperation

Results are presented from successfully designed and fabricated meso-scale ceramic combustors that incorporate internal thermal energy recirculation. The combustor provided sustained operation using propane and air as the reactants. Flames could be obtained well below the normal quenching distance. The development required examination of several different combustor designs and materials. Flammability limits of these combustors have been determined experimentally. Experimental investigations have been performed on the effects of flame holder geometry, material conductivity, equivalence ratio, and inlet Reynolds number on the combustor performance. Measurement of the reactant preheating and product exhaust temperatures was performed using K-type thermocouples which were installed with minimal intrusion to the flow. The reactant preheating temperatures were observed to be in the range 700 K–1000 K. However, the combustor suffered significant overall heat loss (50–85%) which was implied by the low exhaust temperatures (500 K–750 K). For a constant fuel flow rate, the exhaust temperature increased monotonously with decrease in equivalence ratio until the blow-off condition implying that the combustor’s maximum thermal efficiency occurs at its lean blow-off limit. Thermal imaging of the combustor walls was performed using infrared camera to obtain the temperature distribution within the combustor. Numerical simulations were performed with the aid of CFD software using a heat loss coefficient chosen so as to give best correlation with experimental results. These CFD simulations helped to obtain better insight of the dependence of combustor performance on thermal conductivity of the material and heat load.     

Numerical Study of the Swirl Effect on a Coaxial Jet Combustor Flame Including Radiative Heat Transfer

A numerical study of the swirl effect on a coaxial jet combustor flame including radiative heat transfer is presented. In this work, the standard k-ε model is applied to investigate the turbulence effect, and the eddy dissipation model (EDM) is used to model combustion. The radiative heat transfer and the properties of gases and soot are considered using a coupled of the finite-volume method (FVM), and the narrow-band based weighted-sum-of-gray gases (WSGG-SNB) model. The results of this work are validated by experiment data. The results clearly show that radiation must be taken into account to obtain good accuracy for turbulent diffusion flame in combustor chamber. Flame is very influenced by the radiation of gases, soot, and combustor wall. However, swirl is an important controlling variable on the combustion characteristics and pollutant formation.     

Combustion of hydrogen–air in catalytic micro-combustors made of different material

Micro-combustors have low stability, thus catalyst is applied to improve it. In this experiment, the performances of catalytic micro-combustors made of different materials (quartz glass, alumina ceramic, copper) are compared. Asbestine threads are used as the catalyst supports of Pt, and installed in the combustors. According to the experimental results, the combustors have high stability, they keep working until the extreme equivalence ratio close to 0. The stability limits of homogeneous reaction in the quartz glass and alumina ceramic combustor range from 0.0907 to 8.69 and 0.158 to 7.31 on average, respectively. But the two combustors exhibit obvious hot spots, which are 1058 and 728 K at 0.2 L/min, respectively. Whereas the copper combustor has low and uniform temperature distribution on its surface. Moreover, the heat loss in the quartz glass combustor is 4.13 W higher than in the copper one at 0.2 L/min, which is opposite to the conventional situation that heat loss increases with the wall thermal conductivity. Computational fluid dynamic simulation reveals that the reaction modes inside the combustors differ. The higher wall thermal conductivity makes the heterogeneous reaction dominate, thus induces the temperature distribution and heat loss aforementioned.     

Development of preliminary design program for combustor of regenerative cooled liquid rocket engine

An integrated program was established to design a combustor for a liquid rocket engine and to analyze regenerative cooling results on a preliminary design level.Properties of burnt gas from a kerosene-LOx mixture in the combustor and rocket performance were calculated from CEA which is the code for the calculation of chemical equilibrium.The heat transfer of regenerative cooling was analyzed by using SUPERTRAPP code for coolant properties and by one-dimensional correlations of the heat transfer coefficient from the combustor liner to the coolant.Profiles of the combustors of F-1 and RS-27A engines were designed from similar input data and the present results were compared to actual data for validation.Finally,the combustors of 30 tonf class,75 tonf class and 150 tonf class were designed from the required thrust,combustion chamber,exit pressure and mixture ratio of propellants.The wall temperature,heat flux and pressure drop were calculated for heat transfer analysis of regenerative cooling using the profiles.     

A Numerical Study for Heat Transfer Characteristics of a Micro Combustor by Large Eddy Simulation

The characteristics of heat transfer in confined multiple jet flows of a micro can combustor is investigated by means of large eddy simulation (LES). The micro combustor can be employed for a hybrid system, which consists of a micro gas turbine and a solid oxide fuel cell. In the present study, the focus is brought into heat transfer, which has a great effect on combustion stability as heat loss to the outside of combustor. The study is made for the three cases of different baffle plate configurations with changing the velocity ratio between fuel and oxidant jets. Downstream of the baffle plate, the flow recirculation regions appear and they can affect the enhancement of the turbulent heat transfer to the wall. In particular, the near-wall flow recirculation region formed between the oxidant jet and the combustor wall plays an important role for wall heat transfer. We study the turbulent thermal fields and conjugate heat transfer which show peculiar characteristics corresponding to the three different baffle plate shapes and different velocity ratios.     

Combustion characteristics and thermal enhancement of premixed hydrogen/air in micro combustor with pin fin arrays

Targeted at improving the combustion stability and enhancing heat transfer in micro combustor, the combustion characteristics and thermal performance of micro combustor with pin fin arrays are numerically investigated by employing detail H₂/O₂ reaction mechanism. It is shown that the micro combustor with staggered pin fin arrays exhibits the highest average temperature and heat flux of external wall, while the micro combustor with in-line pin fin arrays displays the most uniform temperature distribution of external wall. When the equivalence ratio is 1.1, all micro combustors exhibit the highest mean temperature and heat flux of external wall. The micro combustor materials with high thermal conductivity can not only improve the average temperature and heat flux of external wall, but also enhance heat transfer to the upstream which can preheat the mixed gas. Therefore, the materials with high thermal conductivity, such as red copper and aluminum, can make up for the nonuniform temperature distribution of micro combustor with staggered pin fin arrays, so as to realize uniform high heat flux output of external wall.