RCFB-FGD技术在银川热电厂的应用

详细介绍了德国WUIYF公司的回流式循环流化床烟气脱硫工艺(RCFB-FGD)和该技术在银川热电公司#4、#5炉的应用情况，对应用过程中出现的流化床差压波动大、脱硫效率调节跟踪滞后及二级电除尘出口烟尘浓度过大等问题的解决方法进行了细致的分析，并针对该技术的配置提出了建议。     

Experimental study on the attrition and size distribution of bed material in a recirculating fluidized bed

An experimental study was performed on the attrition of the bed materials in a recirculating fluidized bed (RCFB) using Indian standard (IS) grade I sand (size between 2.0 and 1.0?mm) at ambient conditions. Experiments were performed with superficial air velocity ranging from 7.13 to 9.16?m/s, bed inventory of 7–10?kg, and a spacing of 0.085?m between the jet top and draft tube bottom. The main objective of the study was to investigate the effects of operation time on the attrition and size distribution of sand particles in a RCFB. It was noticed that the prime mode of attrition of bed materials was abrasion, not fragmentation. Reduction in the downcomer bed height was observed with increasing operation time. It indicates that attrition was significant and fines were elutriated out with the fluidizing air. Furthermore, variations in the shape, size, and harmonic diameter of particles were studied with increasing operation time. It has been observed that the coefficient of uniformity and coefficient of curvature showed increasing patterns. It specifies that particles of different size ranges and fines were formed due to attrition of particles. At the end of the operation, it was found that a significant amount of fines was elutriated with fluidizing air from the reactor.     

Effects of the attrition of bed material on the solid circulation rate in a recirculating fluidized bed

Effects of attrition of bed material on the solid circulation rate in a recirculating fluidized bed (RCFB) were studied in detail. Effects of different operating and design parameters such as operation time, superficial velocity, bed inventory, particle size, and spacing between jet top and draft tube bottom on the solid circulation rate in terms of attrition were studied. A mathematical model was developed on the basis of experimental results to identify the effects of attrition of bed particles on the solid circulation rate incorporating the effects of the various operating and design parameters. To develop the model, dimensional analysis and nonlinear regression were used. The model equation was a nonlinear equation, which implies a relationship between the solid circulation rate and other operating and design parameters. The model equation can estimate the solid circulation rate over a range of operation time and other parameters. Decrease in solid circulation rate can be predicted with increasing operation time, using the model equation.     

RCFB技术在应用中存在的问题及优化改进

广州恒运集团公司的RCFB项目是我国目前引进已建设投产的最大干法脱硫工艺。介绍该系统的工艺流程,对系统在安装、调试、投产阶段存在的问题进行了分析并提出优化改进措施。首次引进RCFB技术是成功的,对我国脱硫技术开发应用有着深远的意义,目前在国内已有在建和即将投产的300MW机组采用了这种技术。     

2×300MW机组回流式循环流化床烟气脱硫技术的应用

以回流式循环流化床（RCFB）干法烟气脱硫技术在漳山发电的应用为例，介绍了大型干法脱硫装置的系统布置、技术规范、运行控制及性能参数的调节，并对运行中常见的故障现象进行了分析，提出了可借鉴的经验。     

Clarification of an improved cluster renewal model (ICRM) for heat transfer characteristics in a rolling circulating fluidized bed (RCFB)

This paper presents a novel method to predict the gas layer thickness δ′ in an improved cluster renewal model (ICRM) to calculate the heat transfer coefficient h′_c for a rolling circulating fluidized bed (RCFB). Eulerian-Eulerian two-fluid model (TFM) with kinetic theory of granular flow is used to perform a numerical simulation. After comparing the pressure gradient −△p/△z′ and the simulated heat transfer coefficient between multiphase and the wall h_gs with previously published experiment data, the correctness and reliability of the simulation are able to be verified. In conclusion, firstly, the variation of h′_c calculated from δ′ in the ICRM is almost the same with h_gs in the case that the RCFB undergoes the rolling motion. In order to quantitatively evaluate the proposed novel method, an error percentage α between h′_c calculated from δ′ and h_gs is 2.043% which is less than 5%. This certified that the novel method to predict δ′ in the ICRM has higher accuracy to calculate h′_c. Secondly, h′_c calculated from δ′ is mainly influenced by rolling amplitude Θ rather than by rolling period T. Specifically, with the increase of Θ, amplitudes of T_s are decreased, which is caused by the increased heat transfer and the decreased δ′ between cluster and wall. The decreased amplitudes of T_s are able to increase heat transfer efficiency, which eventually increases h′_c. Thirdly, in the case that normalized rolling period t/T is changed from 0 to 0.5, higher h′_c calculated from δ′ in Region Ⅰ results from the large local cross-sectional particle volume fraction c_local in Region Ⅰ with a smaller δ′, while lower h′_c calculated from δ′ in Region III results from the smaller c_local in Region III with a larger δ′. Therefore, it is concluded that h′_c calculated from δ′ is able to well predict the bed-to-wall heat transfer coefficient of the RCFB even if the rolling motion is considered.     

高浓度布袋除尘器在内回流循环流化床烟气脱硫系统上的应用

对内回流循环流化床(RCFB)烟气脱硫系统二级电除尘器烟尘排放超标,改用高浓度布袋除尘器,运行后烟尘排放浓度小于50mg/m3(标准状态)。这种布袋除尘器控制简单,运行稳定可靠,滤袋防腐抗湿性能好,使用寿命长。