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1.
Aiming at the questions of raceway section two dimension temperature distribution from two dimensional image accumulated by three dimensional radiation space and three dimensional temperature reconstruction error caused by limited charge coupled device (CCD) sensors for a sudden spread combustion chamber, the two dimension rectangle interpolation virtual CCD sensor installation algorithm is provided as a new technology for solving the difficulties of installing more CCD sensors and filtered back projection reconstruction error caused by limited projection numbers. The radiation intensity projection data got from flame image collected from the installed CCD sensors and computed virtual CCD sensors is interpolated for filtered back projection to computer intensity distribution and calibrated bi color method is used to calculation temperature in raceway depth direction. The results of experiments on a mini type coal gas furnace and practice test showed that the algorithm is accurate and credible and realized the on line monitoring for sudden spread combustion chamber raceway depth direction. At the same time, the useful information is provided for further studying combustion working state for the sudden spread combustion chamber.  相似文献   

2.
The manipulators pay fully attention to the running state of raceway looked into tuyere peehole in blast furnace in its production process. And it is important for judgement and control the blast furnace. The pulverized coal feeding and burning cases can be supervised by peehole in tuyere. Temperature distribution can be studied by brightness and numerical simulation of pulverized coal combustion. The recent research of temperature examined and supervision technique of the tuyere and raceway in blast furnace are set forth at home and abroad. A method settling supervision and control the state of tuyere and raceway in blast furnace is put forward by coalescent numeric image process technique to numeric simulate two dimensional imaging technique.  相似文献   

3.
We developed a process model of flame beam transmission using pulverized coal powder and coke combustion in a raceway. We employed a Monte Carlo computation method equation based on charge couple devrce(CCD) target heat flow distribution for radiation heat transfer. We explored the factors impacting radiation transmission. Based on these, a three dimensional reconstruction was analyzed at varying coke particle concentrations. This model provided an effective method to produce on line monitoring of raceway working states.  相似文献   

4.
The essay introduces the research status, the design principle, the composition and the test of the CCD-based imaging and monitoring system in the raceway of blast furnace. The CCD-based imaging and monitoring system in the raceway can show the running statement of the raceway in the monitor of operate room continuously, which enables the BF operator to observe the lightness and activity of raceway, the status of coal injection, the dilapidation of raceway and enhances the correctness of operate. Meanwhile, the system can transport the burning image of raceway to the computer, experimental results of which indicate the temperature error between the image-digitalize method and the measuring result is within three percent. The sustem can satisfy the demand of engineering.  相似文献   

5.
双层对向正反燃烧单体供热技术在烤烟烘烤中的应用研究   总被引:2,自引:1,他引:1  
为提高烤烟烘烤中燃料利用率,降低烘烤成本,减少环境污染,研究采用1个供热炉设上下2个炉膛,实现正向和反向同时对向燃烧,对比研究了双层对向正反燃烧单体供热设备和普通加热设备烤房烤烟烘烤性能。煤的燃烧充分,传统烟气中所含CO、CH4、碳粉尘等可燃物能得到充分、高效燃烧及利用。空载测试升温速率60℃/h,比普通烤房提高34℃;烘烤实载时,各阶段实测温湿度与目标温湿度吻合度高,完全能满足烘烤工艺的控制要求。双层对向正反燃烧单体供热设备烤房平均每千克干烟耗煤量、耗电量、综合能耗成本分别比普通烤房减少0.31 kg、0.05 kWh和0.33元,降幅分别为17.73%、14.36%和17.46%;烘烤操作等日常用工成本较普通供热设备少0.52元,降幅43.93%,且对烟叶烘烤质量无明显影响。双层对向正反燃烧单体供热设备升温速度快,平面温度均匀,烘烤过程中温湿度控制精准,能有效降低烘烤能耗和用工成本。  相似文献   

6.
According to the volatile combustion, the mathematical and physical models on the volatilization combustion of coal field fire area are established. The governing equations are analyzed by analytic method. The parameters such as volatilization combustion speed, the content of volatile component and the flame temperature are obtained at relatively high temperature environment. According to the solutions, the flame temperature of the volatilization combustion is calculated by the heat insulation temperature in the light of the low-heat value of the volatile component. Due to the free or forced convection in the actual fire area, the true temperature would be lower than the calculation. Through experiment, heating process takes the greatest impact on the heating surface but least on inner parts. The temperature is increased and the heating surface temperature will exceed the temperature and continue increasing, which indicates that the coal begins oxidation. While the airflow is increased, the temperature will be slightly increased. The temperature is descent more slightly in the coal temperature because of thermal radiation.  相似文献   

7.
The temperature rise rate in oxidation process of gangue and coal specimen from Jingang Coal Mine has been investigated and the sulphur configuration in various kinds of gangue has been quantitatively analyzed to explore their spontaneous combustion mechanism. It is proved that the content of FeS 2 is very high in gangue of Jingang coal mine. A great deal of heat is released with the oxidation of FeS 2 in pyrites, the accumulation of heat results in gangue spontaneous combustion when the temperature reaches a certain degree.  相似文献   

8.
对3种不同自燃倾向性煤样进行低温氧化实验,利用CO体积分数与煤体温度间变化的计算模型,求解出活化能和煤氧化过程发生转变的特征温度,同时结合热重-差示扫描量热(TG-DSC,theremogravimetric analysis-differential scanning calorimetry)实验结果,分析了不同自燃性煤氧化特性和活化能的低温表征规律。结果表明:1)低温氧化阶段,CO生成量、耗氧量和耗氧速率随着煤自燃倾向性增强而增大;不同煤样在实验过程中出现同样的CO生成量和耗氧速率急剧上升的温度拐点,且煤的自燃性越强,该拐点温度越低,同时CO体积分数的变化具有明显的阶段性。2)不同自燃性煤氧化阶段活化能变化规律存在显著差异,当各煤样的温度到达活性温度时,活化能快速减少,且活化能变化点对应于煤氧化过程发生转变的特征温度点。3)根据煤特征温度和活化能的变化规律,把煤低温氧化进程分为4个阶段,分别为表面氧化、氧化自热、加速氧化和深度氧化。  相似文献   

9.
This paper conducts the full size three-dimensional combustion numerical simulation study on the low-calorific value coal bed gas combustor. It explors the effects of different ratios of swirling wind and straight wind on flow field,temperature field and concentration field when this combustor combusts coal bed gas which methane volume concentration is 30 percent. The optimal ratio of swirling wind and straight wind is gained. Based on this,the number and obliquity of cyclone vane in gas pipeline are further optimized. The results show that when ratio of straight wind is 80 percent and ratio of swirling wind is 20 percent,the good jet flow rigidity is not only possessed,but also the strong spin momentum is brought. Reverse axial velocity grads and reverse velocity in central backflow region are also big,the burning temperature and combustion efficiency are high,and high-temperature region is diffusely distributed. When the number and obliquity of cyclone vane are respective 6 and 60,the mass fraction of methane descends quickly,the mass fraction of methane is low in outlet of combustion region,and the combustion efficiency is high.  相似文献   

10.
高效助燃除硫剂在烟叶烘烤中的应用   总被引:1,自引:1,他引:0  
为了降低烟叶烘烤过程中煤炭燃烧时有害气体排放量,改善煤炭燃烧性能,进行了高效助燃除硫剂的应用试验。结果表明:燃煤中添加3%的高效助燃除硫剂能改善燃煤的燃烧性能,使燃煤燃烧更加充分,炉膛内平均温度较对照提高53.67℃,助燃效果明显,有利于提高燃煤利用率,降低能耗。烟叶烘烤时,燃煤中添加3%和1%的高效助燃除硫剂,耗煤量及燃烧时产生的碳氧化物、氮化物及硫化物都有不同程度的降低,其中除硫效果显著。  相似文献   

11.
为了研究灰分对煤自燃能力的影响作用,利用绝热氧化实验装置对不同灰分含量煤样进行升温氧化实验,采用R70TCPTB 3种指标表征灰分含量对煤样自发氧化过程的影响。结果表明:1)灰分含量越大,煤样低温氧化阶段温升速率越小,温升加速点温度越高,煤样的自发氧化过程越慢,煤越不易自燃;灰分含量大于40%后,煤自燃倾向性快速减弱。温升加速点是反应微观信息的零活化能温度的宏观累计结果,具有直观且滞后的特点。灰分越大,滞后越明显,温差越大。2)R70TCPTB 3种指标与灰分关系表现为二次函数。R70TCPT两种指标显示灰分越大,自燃倾向性越弱,与实践经验相符。受水分权重影响,B指标显示煤样在灰分小于40%时,灰分越大,煤样自燃倾向性越强,这与实践经验相悖。因此,B在判定灰分对煤样自燃倾向性的影响时具有一定的局限性。  相似文献   

12.
Based on the analysis of flowing combustion, gasification reaction, and lumped parameter, a three region model is established to predict the temperature and gas components of Texaco coal gasifier. Using mass balance and energy balance equations to each zone, the model takes account of gas solid two phase flow, coal pyrolysis, radiation heat transfer, and heterogeneous and homogeneous kinetic chemical reactions. Based on the model, a program is developed for dynamic and static simulation. After parameterization and simulation analysis, some important trends and conclusions are attained. Because the model can accurately predict the temperature and gas components in jet region, it has widespread engineering application value.  相似文献   

13.
The research on volume conductive model can be used in designing the conductive systems and optimizing the energy transfer parameters. By considering the coupling of circuit, electromagnetic-field and temperature-field, a 3-D multi-filed coupling model is developed. On the circuit level, the simulation of volume conduction, real-time monitoring for the temperature of skin tissue are achieved, which provides direct theoretical guidance for energy transfer optimization design. With the software FEM 3.5, a volume conduct multi-field coupling model is built to verify the feasibility of volume conduction, which also lays foundation for further optimize energy transfer efficiency.  相似文献   

14.
Based on inevitability analysis of Tuyere coal and Raceway coke combustion numerical simulation, this paper retrospects previous study and summarizes two phase turbulent flow numerical model of pulverized coal and air, pyrogenation and radiation transmit-heat numerical model of pulverized coal volatile ash, combustion energy equation of coke grain. The authors put forward a new idea of boundary condition using CCD technique.  相似文献   

15.
The characteristic of the original damage and the breaking of the coal and rocks under the loading has been discussed by a lot of microscopic structure analysis and by whole stress strain testing on the coal and rocks. The non homogeneity causes the stress locating in a small spot. It is the essential cause of the damage developing and causing the structure breaking of the coal rocks. The failure of brittle fracturing, rubbing later on and granulating should be a major pattern in the outburst of coal and gas. The method of the examining damage by the deviator stress, is proposed. It can be used to analyse the characteristic of the coal and rocks.  相似文献   

16.
微型内燃机微燃烧过程对当量比和转速变化非常敏感,采用层流有限速率模型和甲醇氧化反应机理对其预混层流微燃烧过程开展仿真研究,探讨当量比和转速对微燃烧特性的影响规律及临界运行参数。在此基础上,提出采用热着火理论和化学反应动力学理论探索当量比对微燃烧特性的影响机理。结果表明仿真与实验比较吻合。当量比从0.6增加到1.1时,燃烧速率增加,压力和温度增加,压力最高值增加约1.5E+6 Pa,温度最大值增加约1 300 K,此后随当量比增加,燃烧速率减小,压力和温度减小。研究还进一步揭示了当量比影响微燃烧特性的机理: 稀燃区当量比主要通过温度变化来影响微燃烧特性,随当量比增加,燃料浓度增加,燃烧释放的总热量增加,所以温度和压力增加,燃烧速率增加;浓燃区当量比主要通过氧气量变化来影响微燃烧特性,当量比越大,氧气量越不足,基元反应速率越小,所以燃烧速率越小,温度和压力越低。转速越高,燃烧时间越短,燃烧越不充分,所以温度、压力越低。受微燃烧相对热损大、驻留时间短的特征影响,微型发动机实现完全燃烧的运行区域较窄,其实现完全燃烧的稀燃极限约0.9,最高转速约6 000 r/min。这在设计微型内燃机时值得关注。  相似文献   

17.
The technology of coal dust explosion suppression is an important means for coal dust explosionproofing. The core of this technology is to develop the inhibitor with effective explosion suppression performance. Firstly, the mechanisms of 3 inhibitors are analyzed, namely physics-based, chemical-based and mixture-based mechanisms. Secondly, the existing inhibitors are categorized and the basic property of the novel inhibitor is put forward. Then, the technology of synergistic mixtures is adopted to tap inhibitors by choosing 3 monomers (aluminum hydroxide, ammonium polyphosphate and diatomaceous earth) and synthesizing, and finally get 3 new inhibitors A, B and C. Utilizing 20 L spherical explosion test system, based on the index of parameters of explicability, the effect of the novel inhibitor is verified by explosion testing. The results indicate mixtures of inhibitors obtain good results, realize synergism and perform much better than traditional inhibitors.  相似文献   

18.
The common finite element method microcomputer software for simulation of the temperature field is developed by authors. It is used for calculating the temperature field duringthe mending process of iron casting defects by means of the dissolution-diffusion bonding technology. The correctness has been proved by testing results. This software has been used to analyse thecaused of hardness rising in heat effecting zone,and also find out the approach for solving the problem.  相似文献   

19.
As a large burning coal country, resolving the SO2 letting problem is the most important thing in the environment protection work. Electric power industry reveals the supply's load rate declining and the discrepancy between apex and vale augments year after year. It makes the load adjustment become an imminency task in the electric power industry. The article popularizes the light power saving technology in the inhabitant living lighting power through reinforcing the DSM technology. It studies the influence on energy and environment after using the technology. It studies avoidable electricity quantity, avoidable electricity power, avoidable apex load, avoidable coal consuming and avoidable SO2 lettling. At last, it makes a concrete analysis with a city's example.  相似文献   

20.
There is no appropriate method or uniform standard for evaluating the pozzolanicity of CFB sulphur-fixed coal ashes,leading to difficulty in use of it as building material,because CFB sulphur-fixed coal ash has higher content of f-CaO and SO_3 than that of ordinary ash.In this paper the appropriate evaluating methods are developed through theoretical analysis and experiments with reference to the National standards GB2847 for the pozzolanic materials and GB12957-91for the testing method of the activity of the industrial wastes,the compressive strength ratio is suggested by determination of 28 day compressive strength ratio of ground CFB sulphur-fixed coal ashes-clinker to ground clinker.It is shown that this evaluating method gives the results consistent with those from other methods.  相似文献   

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