共查询到20条相似文献,搜索用时 78 毫秒
1.
锅炉刚性梁是稳定炉膛及烟道的重要结构,具有降低炉膛及烟道震动、提高炉膛及烟道抗冲击的能力;同时刚性梁还为炉膛及烟道建立整体的膨胀中心,保证炉膛及烟道有序可控的膨胀。故刚性梁的安装质量是锅炉安全可靠运行的重要保证。本文主要介绍超临界锅炉刚性梁的结构及原理,安装中的注意要点、工艺要求和简单的问题处理。 相似文献
2.
3.
4.
二甲醚在柴油机上的应用与研究 总被引:2,自引:0,他引:2
分析了二甲醚的化学结构及理化性质,指出二甲醚是柴油机清洁的代用燃料,给出在柴油机上使用纯二甲醚及含甲醇及水的二甲醚的燃料特性及排放性能比较。 相似文献
5.
王文林 《电网与水力发电进展》2014,30(10):72-76
基于可视化的基础理论,详细阐述了电网智能调度预警系统可视化的总体设计、软件结构、硬件结构及概念设计,并对该系统的使用效果做了介绍。电网智能调度安全预警体系包括基础平台和高级应用两大部分。在线监视及可视化的功能主要包含:潮流可视化显示、元件参数的可视化显示及维护、主变负载率的监视及可视化、线路传输容量的监视及可视化、母线电压的监视及可视化。将该系统应用于黄山电网中,结果表明,该系统的应用使得大量数据得以合理的显示及维护,提高了运行人员的工作效率。 相似文献
6.
7.
750 kV紧凑型交流输电关键技术研究 总被引:5,自引:3,他引:2
介绍了750kV同塔双回紧凑型交流输电关键技术研究的重点成果。研究了在西北高海拔地理环境下包括过电压与绝缘配合、无功补偿、潮流不平衡及导线换位、导线选型及排列方式、外绝缘特性试验、电磁环境、杆塔及基础、雷电性能、电晕特性及海拔高度影响、绝缘子串形式及力学特性、绝缘子串电位分布及均压环优化配置、相间间隔棒配置及机电特性试验、导线舞动及脱冰跳跃抑制措施、带电作业、继电保护15大项技术内容。该关键技术研究属国际首创性科研工作,填补了在高海拔地区750kV紧凑型输电技术的空白。 相似文献
8.
9.
燃煤电站富氧燃烧及二氧化碳捕集技术研究现状及发展 总被引:2,自引:0,他引:2
本文对富氧燃烧和二氧化碳捕集技术的节能机理及其带来的社会效益进行了较为详尽的阐述,介绍了富氧燃烧及二氧化碳捕集技术的发展历程及现状,指出富氧燃烧及二氧化碳捕集技术在节能及环保方面将有广阔的前景。 相似文献
10.
11.
文章从传热学的角度提出一种适用于低压加热器变工况运行时的优化计算方法。介绍了低压加热器的功能原理及传热过程。分析了给定端差计算法的局限性。构建了优化的低压加热器内部传热理论模型并对其求解过程进行了描述。给出了定面积和定端差2种不同情况下,加热器参数与给水参数的变化关系曲线。根据计算结果对加热器在变工况条件下运行时的参数特性进行了分析。 相似文献
12.
低加凝结水温升不足带有普遍性。针对NC25型供热机组低加凝结水温升不足的问题,从作功不足、真空变化、排气损失等方面对机组热经济性的影响进行定量分析,为给水回热系统节能改造提供依据。 相似文献
13.
等效热降法在凝汽式机组经济性分析上的应用 总被引:1,自引:1,他引:1
根据等效热降理论,对火电机组轴封加热器射汽抽汽器、厂用蒸汽、凝结水过冷却度、高加给水旁路渗漏、低加疏水泵等设备经济运行进行了定量分析,为节能降耗提供理论依据。 相似文献
14.
15.
16.
某50MW机组自投产以来,运行中一直存在凝汽器真空偏低、17号级缸温超标、5号低压加热器加热效果极差等缺陷,针对上述问题提出了具体的解决办法。 相似文献
17.
从300MW高压给水加热器热力设计与计算出发,基于最优化设计的思想与方法,以胜利300MW高加热力设计与计算为例,探讨热力设计与计算优化设计问题,揭示热力设计与传热计算对决定高加性能和技术指标,重量,成本,运行可靠性等,所起到的至关重要作用,可供设计者参考。 相似文献
18.
Ajith Moparthi Ranjan Das Ramagopal Uppaluri 《Numerical Heat Transfer, Part A: Applications》2013,63(10):846-860
In a radiating-conducting planar medium with a boundary as the heater surface using an inverse analysis, this work deals with the design methodologies to understand the inherent relationship between heater surface temperature/flux, design surface temperature/flux, and medium properties. The heat flux on the heater surface is chosen as the fitness function. Subsequently, to achieve maximum and minimum design surface heat fluxes, an optimization was done to evaluate the zone of operation of the heater. In addition, the effect of medium properties on the temperature-flux relationships on both surfaces has been studied. The distance between the two surfaces is also considered a parameter. The medium properties, the distance between the surfaces, and the heater surface temperature have been found to have a great impact on the design surface heat flux. The inverse mixed boundary problem has been solved using the lattice Boltzmann method (LBM), the finite-volume method (FVM), and the genetic algorithm (GA). Results of the present study provide a guideline towards the efficient design of a heater in which conduction and radiation are the dominant modes of heat transfer. 相似文献
19.
Electric heaters are used extensively in many industrial applications including air conditioning, water heating, and drying of crop and other materials. There are several interacting parameters that affect heater performance and contribute to its operating and manufacturing costs. The design parameters of interest included coil length, coil diameter, helix diameter, coil pitch, number of turns, coil emissivity, heater wall emissivity, applied voltage, air flow rate, air temperature at the heater outlet, insulation thickness, and the heater dimensions. An objective function for the heater cost was defined in terms of the total annual costs for energy usage and manufacturing. The manufacturing cost included the material cost of the heater, the cost of coating the heater coil, and the cost of insulating the heater. A detailed model describing the performance of a conical heater was utilized to evaluate and minimize the objective function. The optimization problem was completely defined by introducing fourteen inequality constraints, three equality constraints, and ten design variables. The univariate search was used to reduce the number of inequality constraints. The direct search and variable metric methods were used to optimize the objective function at different values of the applied power and air temperature at the heater outlet, leading to the same results. The optimization results indicate that the optimum heater design was found at the minimum values of the coil diameter, conical angle, coil emissivity, and the maximum value of coil temperature. The maximum operating temperature of the optimum heater design (a heater with a silver coated coil) is substantially lower than the maximum normal operating temperature so that longer life for the heating element is expected. The effect of varying the applied power on the objective function showed that as the applied power increases the objective function may increase or decrease, depending on the combined effect of increasing the coil length and heater efficiency and decreasing the insulation thickness. The effect of varying the air temperature at the heater outlet on the objective function indicated that as the air temperature increases the objective function increases. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献