共查询到20条相似文献,搜索用时 490 毫秒
1.
采用锅炉给水的面式减温器过热蒸汽侧并非单相换热而是伴随凝结过程的双相换热.减温器应布置在高于过热器受热面之处且蒸汽应自上而下流动;带烟气调节挡板的过热器设计工况并非锅炉的额定工况而是保持过热蒸汽温度为额定值的锅炉最低工况;不要将低压锅炉过热器紧靠炉膛布置直接承受辐射热. 相似文献
2.
目前有一些单位在(2t/h)低压小容量的工业锅炉上加装了过热器,这样做无论是经济性或安全性都是不合适的。其主要原因: 1.低压小容量的工业锅炉水处理设备都较简单,运行管理水平较差,给水质量低劣。而低压小容量的工业锅炉排污系统不完善,有的只有定期排污,因此炉水碱度普遍很高,炉水含盐量大大地超过允许极限值,锅炉蒸汽含湿量很高,蒸汽携带严重,过热器内壁严重地结有盐垢,过热器管壁传热恶化,,使过热器长期超温变形,锅炉被迫停炉,影响工业生 相似文献
3.
4.
5.
工业锅炉过热器安全性分析及壁温计算软件的开发 总被引:1,自引:1,他引:0
低中压工业锅炉过热器管子内壁向蒸汽的放热系数往往低于1000~1200 W/(m2·℃),甚至低到500~600 W/(m2·℃),加之为适应锅炉大范围变工况,必需加大单级过热器的蒸汽焓增,从而使管壁温度与蒸汽温度之差大于100℃.列举出3个算例,算例应用了所开发的壁温计算软件,其中D型油炉的管壁--蒸汽温差高达275℃. 相似文献
6.
7.
工业锅炉在额定工况下稳定运行时,确定排烟温度是否符合设计排烟温度及相关规程要求,是工业锅炉定型产品热效率测试中的一项重要工作。由于判定方法的不完善,对实际给水温度明显低于设计值的工况下,或无法判断是否符合设计值的情况下,将实测平均排烟温度直接作为测试数据是不严谨的,提出应该采用折算排烟温度作为判定符合性依据及相应计算公式。 相似文献
8.
某用户在用2#锅炉系循环流化床锅炉。锅炉型号SHF20—2.5/400-W 炉渣。额定蒸发量20t/h,过热蒸汽压力2.5MPa,过热蒸汽温度400℃,低温过热器管材20#,高温过热器管材15CrMoG,两级过热器中间设置有面式减温器。锅炉自2002年元月安装完毕,投入运行后实测过热蒸汽温度为395℃,压力≤ 相似文献
9.
1 试验目的 汽水品质试验是锅炉性能考核的重要项目之一。其主要目的是考核锅炉在额定工况、和规定的水质条件下,蒸汽品质是否符合要求,了解锅炉在变工况运行时对蒸汽品质的影响。为制定锅炉正常运行时的汽水质量指标提供实测数据。 2 试验测点及测试方法 试验测点及安装位置见表1。 相似文献
10.
11.
某电厂1号锅炉自投运以来,一直存在非满负荷下二次汽温达不到设计温度即二次汽欠温的问题,对锅炉运行的安全性和经济性带来了不利影响,急需对此进行改造治理。从长期运行数据及热平衡分析看,锅炉的原受热面布置不合理,需要进行改造。在详细热力校核计算的基础上提出了前分隔屏截短1、2和3 m的3种改造方案。通过热力计算结果的全面对比分析,选择对锅炉高温屏式受热面进行截短2 m的改造。改造完成后,锅炉运行稳定,非满负荷下二次汽温欠温问题得到了解决,取得了满意的改造效果。 相似文献
12.
13.
根据国际新工业标准IAPWS—IF97公式计算的数据,利用最小二乘法的原理,在饱和蒸汽的工业锅炉压力等级系列适用范围内,以绝对压力p为变量,拟合出干蒸汽焓h''、干饱和蒸汽比容v''、饱和水焓h'、汽化潜热r(△hv)、饱和水比容v'的函数表达式,最终给出由给水压力pgs和给水温度tgs表示的给水焓hgs给水密度ρgs表达式,这些函数表达式,可用于饱和蒸汽工业锅炉性能试验、热力统计、能源审计等的计算,具有精度高,适用范围大,便捷、实用的特点。 相似文献
14.
为了提高锅炉的自动监控水平,针对目前锅炉监控技术问题,提出了采用嵌入式微处理器为控制器核的锅炉状态参数监控设计方案,通过对监控系统的硬件和软件系统的设计,实现了对水位、烟气氧量、蒸汽流量、蒸汽压力、鼓风风量、炉膛温度等现场物理量的采集和处理,实现了锅炉的实时控制. 相似文献
15.
《Applied Thermal Engineering》2007,27(2-3):509-519
Rifled evaporating tubes are applied in the steam boilers with the aim to increase the steam–water mixture turbulization and to prevent the burnout of tubes walls. The rifled evaporating tubes and the working fluid forced circulation are applied in the steam boiler at the Thermal Power Plant “Kolubara B” that is being built by the Electric Power Utility of Serbia. In order to investigate operating characteristics of the steam boiler of such an advanced design, a simulation and analysis of complex coupled thermal processes on the furnace gas side and thermal–hydraulics inside the evaporating tubes were performed for the whole range of plant operating loads. In this paper a methodology for hydraulic calculations of both forced and natural circulation loops is presented. The increased thermal safety margin of rifled tubes is predicted and compared with the safety margin of smooth tubes for uniform and variable heat loads among walls of the boiler furnace. The rifled tube provides an acceptable temperature of its wall even under a high void fraction of the coolant and prevents the occurrence of critical heat transfer conditions. The influence of the rifled tubes on an increase of the hydraulic resistance in the circulation loop is analyzed. Also, a range of operating conditions under which there is no need for the circulation pumps operation is determined. 相似文献
16.
17.
18.
19.
20.
Integrated pressurized water reactor (IPWR) usually be equipped with once‐through steam generators (OTSGs). The OTSG has many advantages such as simple mechanical structure, smaller size, and higher heat transfer efficiency. It produces superheated steam but with less inventory in its secondary side. The steam pressure is easily affected by steam flow rate or feed water flow rate. This draws more attention to design advanced reactor control system. In this paper, a study has been carried out to analyze the thermal hydraulic performance of an advanced IPWR under steady‐state and transient conditions by using a thermal hydraulic safety analysis code Relap5. An effective load‐following control system is proposed. The steady‐state operating characteristics of IPWR at different load conditions show that the average primary coolant temperature, steam pressure, and coolant mass flow rate are the most important control parameters. Pump frequency conversion strategy and OTSG grouping run strategy are used to study the transient operating characteristics of IPWR. Simulation results of the control system demonstrate its capability in regulating feedwater flow rate and reactor power to follow the change of steam flow rate. According to the results, the OTSG grouping run strategy is optimized to ensure the OTSG operates safely under low load conditions. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献