大型循环流化床锅炉冷渣器的运行故障及改进措施

循环流化床锅炉风水冷渣器运行存在主要问题及原因分析,并提出了改进措施。介绍和推选滚筒冷渣器,发展完善滚筒冷渣器有助于大型循环流化床锅炉安全可靠运行。     

流化床选择性冷渣器运行技术探讨

冷渣器作为循环流化床锅炉的关键设备 ,还存在着各种各样的问题 ,严重影响了锅炉的稳定运行。本文对某台流化床选择性冷渣器进行介绍 ,并对运行技术进行了总结和探讨。     

流化床冷渣器的设计与故障分析

近几年来,循环流化床锅炉(CFB锅炉)技术在国内发展迅速,随着循环流化床锅炉的大型化,采用流化床冷渣器已成主导方向,主要阐述了流化床冷渣器的工作原理、设计,对目前流化床冷渣器运行中出现的故障进行了分析并提出一些解决措施。     

流化移动叠置式冷渣器的发展与运行经验

针对流化床锅炉的热污染,浙江大学开发了一系列新型流化移动叠置式灰渣冷却器。在实验室理论与大量试验的基础上,设计开发制造了冷渣量为1.5t/h冷渣器示范装置和一系列冷渣器产品。1997年为日本一公司锅炉配用的大容量冷渣器（单台冷渣量达7.2t/h）目前已与锅炉一起投入试验生产,运行正常,介绍了流化床移动叠置式冷渣器在浙江大学的发展与运行经验。图6表1参8     

循环流化床锅炉冷渣器的调整与改造

冷渣器是循环流化床锅炉的重要辅机之一,其作用是采用水或空气将循环流化床锅炉排出的900℃左右的高温灰渣冷却至200℃以下,回收一部分灰渣的物理显热,提高锅炉效率,它的正常运行直接影响到循环流化床锅炉的安全可靠和经济连续运行,而冷渣器能否维持正常排渣与冷渣器结构、设计有关外,也与运行人员的操作水平有关,故循环流化床锅炉的排渣系统运行不正常,故障率高是导致循环流化床锅炉不能带满负荷运行或被迫停炉的直接原因之一,针对梅县发电厂三期新投产的2台135 MW机组循环流化床锅炉排渣系统在运行中出现的问题进行分析及探讨,并提出了改造的实施方法。     

循环流化床锅炉冷渣器运行问题及改进措施

冷渣器作为循环流化床锅炉一个非常重要的部件，它的主要作用是将锅炉底部排出的大渣冷却到约200℃以下。冷渣器投运的成功与否直接关系到锅炉是否能够连续稳定地运行。本文根据我公司已经投运的冷渣器实际运行情况，对冷渣器常见的故障进行了原因分析，提出了相应的处理方法。最后，提出了机械式冷渣器和非机械式冷渣器的选型建议。     

循环流化床锅炉冷渣器的调整与改造

冷渣器是循环流化床锅炉的重要辅机之一,其作用是采用水或空气将循环流化床锅炉排出的900℃左右的高温灰渣冷却至200℃以下,回收一部分灰渣的物理显热,提高锅炉效率,它的正常运行直接影响到循环流化床锅炉的安全可靠和经济连续运行,而冷渣器能否维持正常排渣与冷渣器结构、设计有关外,也与运行人员的操作水平有关,故循环流化床锅炉的排渣系统运行不正常,故障率高是导致循环流化床锅炉不能带满负荷运行或被迫停炉的直接原因之一,梅县发电厂三期新投产的两台135MW机组循环流化床锅炉排渣系统在运行中出现的问题进行分析及探讨,并提出了改造的实施方法。     

风水共冷式冷渣器及其经济性分析

采用冷渣器是降低流化床锅炉灰渣物理热损失的有效方法。本文在已有冷渣器的基础上,设计出一种适用于大容量流化床锅炉的新型冷渣器——风水共冷式冷渣器,并分析了这种冷渣器的经济性。     

典型循环流化床锅炉冷渣器的比较

介绍了近几年来冷渣器在循环流化床锅炉上的应用,阐述了国内几种典型的冷渣器的性能及在实际运行中存在的问题,并指出实际工程应用时应结合冷渣器的特点以及混配燃料的实际粒径进行合理选型。     

CFB锅炉流化床冷渣器试验研究

对引进４１０ｔ／ｈ ＣＦＢ锅炉流化床冷渣器进行了试验研究,研究结果表明,冷渣器内的床层压降、流化烟气、冷却水、脉冲阀开关时间等参数对冷渣器的运行状态有较大的影响。在上述研究基础上,提出了相应的改进建议．     

450t/h CFB锅炉风水冷选择性冷渣器冷态模化实验

以某电厂450t／h CFB锅炉的风水冷选择性冷渣器为原型，建立了几何尺寸相似的可视化冷渣器实验装置，采用电厂实际排渣物料进行冷态模化实验，深入研究了该冷渣器的临界流化速度以及在不同料层厚度下的料层压力特性和各仓室在不同配风比下的排渣速率特性。实验表明：实际排渣属宽筛分物料，冷渣器各风室的实际流化风量下限值高于设计值，通过合理调配各仓室的风量比关系可明显提高冷渣器的排渣速率。所得实验数据和运行规律可为冷渣器的可靠运行提供参考依据和操作指导。图8表1参7     

风水联合冷渣器投运前的试验过程研究

哈尔滨锅炉厂有限责任公司生产的220t/h及以上循环流化床锅炉所配的冷渣系统大部分是哈锅和ALSTOM公司合作开发的风水联合冷渣器。就该种冷渣器在投运前的冷、热态试验做了简要说明。     

Development and validation of helical‐coil‐in‐fluted‐tube gas cooler for CO2 heat pump water heaters

A segmented approach [1] for the CO₂ helical‐coil‐in‐fluted‐tube gas cooler is developed. The CO₂ helical‐coil‐in‐fluted‐tube gas cooler consists of helically coiled tube and fluted tube. It is fabricated by twisting a straight copper tube to form helically coiled tube and embedded in the groove of the fluted tube. The available heat transfer and pressure drop correlations for the supercritical CO₂‐side and water‐side are provided to simulate the gas cooler. The simulation is compared with a detailed set of experimental data, for given the inlet conditions. The predicted data matches well with the experimental data with absolute average deviations of 1.15, 4.6 and 4.7% for the CO₂ pressure drop, gas cooler exit temperature and hot water temperature, respectively. Based on the good matches between measured data and predicted data, the detailed thermodynamic processes of gas cooler parameters are predicted and analyzed. Furthermore, different arrangements of the gas cooler within the original package dimensions are simulated and better performance of the gas cooler is obtained under the structural parameters of the 3‐row fluted tube with the inner diameter 12 mm. Copyright © 2010 John Wiley & Sons, Ltd.     

Numerical study on convective flow in a three-dimensional enclosure with hot solid body and discrete cooling

The aim of the present numerical study is to analyze the effect of cooler location and aspect ratio and position of the hot solid body inside the enclosure on three-dimensional natural convection flow in a cubical enclosure. The cooler and heater positions and aspect ratio of the heater in a cavity are examined under different combinations of partially cooling vertical sidewalls and, hot solid body in the cubical cavity. That is, (i) different cooler locations with a fixed size of the hot solid body, and, (ii) centrally located hot solid body with different aspect ratio. The three-dimensional convective flow and thermal arrangements in the enclosure are analyzed using the distribution of streamlines, isosurfaces, and Nusselt number. It is found that the cooler location and aspect ratio of hot solid body play a key role on convective cooling and energy transport inside the enclosure. The unit aspect ratio of hot solid body provides higher energy transport inside the enclosure for all cooler positions.     

影响风水联合冷渣器运行稳定性的因素

本文主要针对影响CFB锅炉风水联合式冷渣器安全稳定运行的因素,进行了详细的分析总结,以寻求更好地解决冷渣器对锅炉安全运行影响的措施。     

Numerical investigation on the heat and mass transfer in a direct evaporative cooler

A simplified mathematical model is developed to describe the heat and moisture transfer between water and air in a direct evaporative cooler. The mass of evaporated water is treated as a mass source of air flow, and the related latent heat of water evaporation is taken as a heat source in the energy equation. The momentum caused by water evaporation is taken into account in the momentum equations. The effective air viscosity and diffusion coefficient are decided experimentally. The models and methods are validated by comparing the numerical results with those of experiment for the same evaporative cooler. The influences of the inlet frontal air velocity, pad thickness, inlet air dry-bulb and wet-bulb temperatures on the cooling efficiency of the evaporative cooler are calculated and analyzed.The cooling effects of the direct evaporative cooler are predicted for use in four different regions in northwest China using the present numerical method and local weather data for air conditioning design. The predicted results show the direct evaporative cooler with high performance pad material may be well applied for air conditioning with reasonable choices for the inlet frontal velocity and pad thickness.     

Performance characteristics of a magnetic Stirling cooler

The quantum mechanics model of a magnetic Stirling cooler is established. The optimal relation between the cooling load and the coefficient of performance (COP) is obtained. The maximum cooling load and corresponding COP as well as the maximum COP and the corresponding cooling load are derived. The optimization criteria for a magnetic Stirling cooler are determined. The results obtained here will be useful for the further understanding and the selection of the optimal operating conditions for a magnetic Stirling cooler. Published in 2002 by John Wiley & Sons, Ltd.     

用于汽车传动系统的多功能板翅式机油冷却器

基于对板翅式机油冷却器特性的分析,延伸引用改型式油冷器特色,发展一种用于商用车辆上可同时满足几种需冷却介质要求的板翅式机油冷却器。该形式机油冷却器可大大减小车辆上油冷器体积,并且简化油冷器水路、油路布局难度。     

Study on carbon dioxide gas cooler heat transfer process under supercritical pressures

In carbon dioxide transcritical air‐conditioning and heat pump systems, the high‐pressure‐side heat exchanger operating at supercritical pressures is usually called as gas cooler. The carbon dioxide gas cooler displays much difference from the traditional heat exchangers employing constant property fluids. The commonly used logarithmic mean temperature difference (LMTD) and effectiveness—heat transfer unit (ε‐NTU) fail for the gas cooler design calculation as the carbon dioxide properties change sharply near the critical or pseudo‐critical point in the heat transfer processes. The new effective heat transfer temperature difference expression for variable fluid property derived by the authors is verified by numeric simulation of the carbon dioxide gas cooler. Moreover, the available correlated models for the cooled carbon dioxide supercritical heat transfer are used to simulate the gas cooler. Detail analysis is made for the deviations among the different models, and for the distributions of local convective coefficient, heat flux, and local temperature of carbon dioxide along the flow path in the gas cooler. Copyright © 2002 John Wiley & Sons, Ltd.