球床模块式高温气冷堆核电站(HTR-PM)采用了"双堆+一机"的多模块设计理念,运行特性较常规单堆核电站更复杂,尤其是启停堆系统运行过程.通过对启停堆系统运行特性进行仿真模拟分析,得出了主蒸汽旁路控制优化方案,结果表明,优化后可以改善旁路系统的调节稳定性和有效解决旁路阀开启时前后压差较大而易造成机组运行事故的问题.

By macroscopic examination, chemical composition analysis, mechanical properties test, metallographic examination, cracking-off morphology observation and energy spectrum component analysis methods, the reasons for the leakages of 1000 MWultra-supercritical boiler S30432 superheater pipe were analyzed. The results show that the failure mode of S30432 superheater pipe belongs to long-term overheating.

The piping stress and thermal displacement corresponding to different types of riser rigid support and hanger devices in different installation directions have been calculated by means of finite element analysis, to further analyze the impact on cracking of adjacent steam tee welds exerted by the constraint effect of riser rigid hangers on angular displacement. It can be seen from the analysis that a riser rigid hanger has a constraint effect on angular displacement, and such a constraint effect, however, is weak and limited on the piping stress and thermal displacement, so the piping stress and supports and hangers are not the main reasons for the cracking of tee welds. In addition, the calculation results alert that for an axial limiting hanger of riser with a dynamic axial pipe clamp and rigid struts, its constraint effect on angular displacement has a significant impact on the piping stress and thermal displacement.

Through analysis of steam and water pipeline vibration cases occurred in power plants,the related frequency spectrum characteristics for vibration of steam and water pipe-lines have been summarized up,and some recommendations for vibration remedy being given.Study shows that the repeatability and stability of major vibration componts in the frequency spectrum graph are better,and the comparability of frequency spectrum graph at same measuring point is higher.The principal vibration boasts periodic vibration behavior;the frequency spectrum graph of resonance vibration is more simple,the spectrum line of principal vibration is outstanding,and that of other vibration being very week;the forced vibration often hasn't principal vibration frequency,in the event of vibration velocity surpassing the set standard,and the pipeline being drastically vibrated,the vibration velocity of several major frequencies may be not high.The remedy of vibration can obtain good result in alleviating vibration when combining with vibration mode analysis for pipelines.

Through preventive process of vibration occurred on medium pressure feed-water pipeline on conventional island in one nuclear power plant,the mutual relationship between the frequency spectrum of vibration and the result of modal calculation has been studied,a preventive scheme of vibration being worked out according to this,and the effectiveness of vibration reduction being evaluated.Combined with the response curve of excited frequency,a vibration-preventing principle for pipelines in power plants has been analysed and sammarized out as in the following:on suitable locations on the pipeline,vibration-preventing device has to be installed,making the natural frequency and oscillation mode at one stage of the pipeline to be eliminated,or making th natural frequency and the oscillation mode to be enhanced to n+1 stage,the main vibration response at one stage of the pipeline will disappear.

采用管道应力计算软件CAESARII对电站低压给水管道进行应力计算，对原设计管道吊点参数进行核对，结合支吊架状态，指出载荷位移存在偏差的主要支吊点．计算分析了管道推力和力矩，对管道现有状态的安全性进行了评定，并提出了整改建议，具有一定的借鉴价值。

Rigid strut have found wide application in control of pipe vibration duo to its good vibration reduction and economical efficiency.A study is conducted on the pipes of a power plant in terms of dynamic load testing of the rigid struts and safety analysis of the pipes,which shows that rigid strut is low in dynamic load and the pipes and rigid strut are safe under the action of static load plus dynamic load.The rigid strut can meet the requirement for long-term safety operation.Other kind of rigid vibration-reduction equipment may also be used for vibration control of pipes.

The reasons leading to abnormal operation of hot reheater steam pipes in No.1 supercritical unit of Ruijin Power Plant of China Huaneng Group during trial operation were analyzed,and the pipe stress was calculated.Based on above analysis,the optimal adjustment scheme of the supports and hangers of the pipe was put forward.After implementation of the scheme,the pipe stress is equalized,the supports and hangers work well,and the requirement of long-term safety operation condition is satisfied.

The load deviation in constant-forced hanging bracket directly affect thermal displacement of the piping system and the performance of said hanging bracket.For this,taking the main steam pipeline of a 220 MW unit in one power plant as example,the relationship between the load deviation in constant-forced hanging bracket and the thermal displacement of piping system has been calculated and analysed.Results show that the vertical thermal displacement is increasing in the event of increasing the load deviation,while the horizontal displacement having remarkable change.In order to control the stress level in the pipeline,it is recommended to select the suitable constant-forced hanging bracket during the time of design.The constant-forced hanging brackets have already been long-term in operation or those of poor quality should be timely adjusted or replaced;the pipeline of ultrasupercritical units should use constant-forced hanging bracket with high quality and little load deviation,to ensure long-term safe and reliable operation of the pipeline and the hanging bracket.

The structure and functions of the maintenance management system for pipelines and their supports & hangers developed by Xi'an Thermal Power Research Institute Co Ltd have been presented.Results of practical application show that the said system reaches purpose of grasping the situation,understanding the trends,and discovering problems appeared on pipelines and their supports & hangers,enhancing the management efficiency,providing guarantee for long-term safe and economic operation of the pipeline system.

对某电厂主蒸汽管道支吊架冷、热态全面检验发现,其支吊架存在多种类型的缺陷,使管道受力处于异常状态,管系一次应力超标,严重影响管道的寿命和安全运行.通过管道应力计算分析,提出了支吊架优化调整方案.依此方案实施后,管道受力合理,一、二次应力合格,支吊架状态恢复正常,能够满足管道长期安全运行要求.

减温减压器是发电厂为其它用户供汽的重要设备,由于运行工况较为复杂,常会泄漏,严重影响设备的安全运行及向用户供汽.通过对减温减压器进行温度场测量和变形分析,找出了泄漏原因,实施改进后效果良好.