两台互备互投软起动水泵的水位控制

我公司恩德炉300m^3／h循环水工程需新上两台75kW水泵。控制要求为：正常水位范围内(低水位以上)两台水泵互为热备用,运行水泵发生故障时备用泵自动投入;若水位降至低水位以下,运行泵停止,备用泵解除热备,直至水位恢复至高水位以上时,运行泵自动投入,备用泵自动恢复热备。     

50ZLQ—54型循环水泵的节能改造

我厂一期工程的两台125MW机组,配有3台上海水泵厂制造的50ZLQ-54型立式循环水泵,循环水为海水,系直流供水开放式循环。正常运行时,一台泵供一台机,另有一台泵备用。两条循环水母管可以并联运行,也可自成一单元系统。     

14NL—14型凝结水泵振动的消除

富拉尔基二电厂200MW机组配套14NL—14型立式全容量凝结水泵及JSLl38—4型、380kw、6000V立式电机。每台机组配备两台,一台运行、一台备用。在已运行的三台机组中均有该型电机横向振动严重超差的问题。3~#机组凝结水泵振动最大,电机曾达0.26mm(2~#泵),泵自由端曾达0.40mm(2~#泵)。1~#、2~#机组凝结水泵及电机振动也均在0.15mm以上。     

单循泵供双机用水的节电工作

我厂一期工程装机容量为两台5万千瓦机组,配备循环水泵3台,其中大泵2台、小泵1台,设备特性规范见表1。循环水为单母管制,凝汽器为双路表面回热式双道制,采用虹吸排水。机组投产后,单机运行时1台小泵供水,双机运行时则需1台大泵和1台小泵并列运行供水。全厂厂用电率高达14％,其中循泵耗电量约占双机运行发电量的2.5％以上。为了节约厂用电,从1979年起,我们通过试验改变了运行方式,由双机运行两台循泵供水改为1台循泵供水,使厂用电率明显下降;同时,落实了一些改进和技术措施,并利用备用泵     

高压变频器在电厂辅机节能改造中的应用

<正>神华亿利能源有限责任公司电厂四台机组的凝结水泵、一次风机、二次风机、引风机电动机总功率为104 860 k W,运行总功率为79 840 k W。为了降低厂用电率,对全厂6 k V高压电动机进行了变频调速改造。1变频改造系统主电路1.1凝结水泵变频控制主电路电厂每台机组配备两台凝结水泵,变频器采用一拖二的方式,即一台变频运行,一台工频备用,实现对凝结水泵的工频、变频的起停操作和运行切     

凝结水泵变频控制在除氧器水位调节上的应用

华能巢湖发电有限责任公司一期工程2&#215;600MW超临界机组共配置4台凝结水泵（以下简称凝泵）,泵的扬程345m、流量1336．37t／h,型号10LDTNB-4PJX;电机采用6kV、1800kW,型号YKSL560-4的空-水冷方式电机。每台机组配置凝结水泵2台,其中1台运行,1台备用。4台凝结水泵将凝汽器内的凝结水送至除氧器,同时向汽轮机低压旁路及减温器提供减温水。凝结水泵能满足机组各种运行工况。当运行泵事故跳闸时,备用泵能自动投入运行;启动、停机以及试验条件下的特殊要求,能就地手动操作,并设有单元控制室控制接口。     

华能大连电厂循环水泵润滑水系统的优化运行

针对华能大连电厂3号、4号机组循环水泵润滑水系统运行中存在的问题,分析其原因,提出了用海水替代工业水的具体技术方案,优化了机组运行方式,实现了冬季每台机组单台循环水泵运行期间备用循环水泵的安全可靠备用,节能节水经济效益显著,提高了系统运行的安全稳定性。     

灰渣泵轴封水系统优化改造及应用

石门电厂灰渣排除方式设计为灰渣混除,炉底渣被捞渣机捞起可以用汽车拖走,也可以经碎渣机碾碎后经灰渣沟汇流至灰渣泵房前的缓冲池内再由灰渣泵排入灰场。灰渣泵共装3组,每组为2级串联运行,正常情况下1组运行,2组备用,泵房内还设计有一级和二级轴封水泵分别为1台运行1台备用。一级轴封水泵供一级灰渣泵的轴封用水,二级轴封水泵供二级灰渣泵的轴封用水。1轴封水系统运行情况轴封水是为灰渣泵的动静密封面起密封作用的,灰渣泵是全厂重要的公用系统设备,1,2号炉所有的除灰及除渣灰水、卫生水、消防水、工业水、生活水等都是通过灰渣泵排至灰场…     

N200机循环水泵控制系统完善化

我厂每台N200机组选用48sh—22型双吸水泵三台,在正常满负荷运行时两泵并列运行,一台备用,运行中任一台跳闸,备用泵均能自动投入,在循环水泵出口阀门上,安装了辽宁铁岭阀门厂生产的HD741X—6型液控止回蝶阀,这种阀门具有截止、止回两种功能。阀门阻力系数小,而且能减少和消除水锤对系统的破坏作用,但阀门控制比较复杂,加之循泵保护设计中,较多地模仿元宝山法国引进机组的线路,使整个泵组控制系统更显繁杂。     

电厂600MW机组炉水泵优化试验探讨

介绍台山电厂600 MW机组锅炉炉水泵经过优化,成功实现炉水泵"两运一备"的运行方式,达到了节能降耗的目的,为企业降低发电成本,提高产品竞争力打下了良好的基础。针对炉水泵"两运一备"方式下运行存在的问题进行分析探讨,提出安全防范策略。     

AP1000核电站额定功率运行时单台给水泵跳闸瞬态分析

AP1000核电站额定功率运行时采用3台33.3%容量电动泵提供给水,无备用泵。通过对100%和70%额定功率平台下给水流量和蒸汽流量的稳态平衡计算,验证了1台泵跳闸后,剩余2台泵能维持电厂70%额定功率运行;并通过对CENTS程序建立的单台给水泵跳闸瞬态的仿真结果数据进行分析,验证了此瞬态下无需快速降功率动作,反应堆功率自动控制系统与蒸汽旁排系统能够将一回路平均温度维持在允许范围内,期间不会发生蒸汽发生器窄量程液位低跳堆事故,上述分析结果对 AP1000核电站调试和运行具有重要参考意义。     

泵与风机的节能探讨

通过改变泵与风机参数,使得泵与风机的性能曲线交至工作点附近,使系统能在最佳工况中运行,降低功率消耗。介绍了泵的选型以及改变泵运行范围的最佳经济方法以及多种泵与风机调节运行工况的特点。     

330MW汽轮发电机组凝结水泵振动大原因分析及处理

针对内蒙古国华准格尔发电有限责任公司变频凝结水泵振动大的问题,通过现场设备运行状态监测、电动机变频全频率段振动测试及振动频谱分析,确定原因为凝结水泵发生系统共振。对此采取在电动机导向轴瓦处增加支撑、提高系统动刚度等措施,有效避开共振区,解决了变频凝结水泵振动大问题,凝结水泵恢复正常运行。     

Centrifugal pump operation monitoring with motor phase current measurement

Centrifugal pumps often operate inefficiently because of their incorrect dimensioning and inefficient control. The economic potential of improving the pumping efficiency has generated a wide market for energy auditing products and services, which determine the prevailing energy efficiency of pump operation. Energy audits are commonly based on additional measurements that might be carried out for a short period of time, covering only a fraction of the pump operation cycle. Often the most feasible solution would be to use the existing measurements in the pumping system to determine its typical operation. Then, the correctness of pump dimensioning and the efficiency of the applied flow control method could be determined simultaneously for a large group of pumps, as there would be no requirements for additional measurement sensors on each device.In this paper, a current measurement-based approach to monitor centrifugal pump operation and its energy efficiency is studied. This approach allows a simple realization of energy audits for fixed-speed pumping systems, where only current consumption of the electric motor is measured. Approach is based on adjustable models for motor and pump operation, which in this case are configured for a laboratory pumping system. Factors affecting the estimation accuracy of the motor operation are also analyzed in the paper. According to the conducted tests with the laboratory setup, the motor shaft power can be estimated with the accuracy of 3.2%, and the pump flow rate with the accuracy of 16%. This accuracy class can be considered sufficient for energy auditing and monitoring purposes, since it allows detection of inefficiently operating pumps. After this, more accurate measurements with separate measurement instrumentation and more detailed pumping system energy efficiency analysis can be carried out.     

氢冷发电机组密封油真空泵系统优化与改进

包头第三热电厂氢冷发电机组密封油真空泵系统改造前,原配备1台水环真空泵及2台罗茨泵,水环真空泵异常时,真空油箱真空无法保证,影响机组的安全稳定运行.经分析,决定在密封油真空系统中增加1台备用水环真空泵,同时取消罗茨泵组.系统改造后,机组各项技术指标均能满足要求,每年可节约厂用电量26.28 MWh.     

凝汽式机组循环水泵的优化运行方式分析

在影响凝汽器真空的很多因素即循环水进水温度、机组的负荷、凝汽器的清洁度不变时,根据电厂现有的循环水泵台数,通过改变循环水流量,提高凝汽器的真空,利用低成本软件运营系统,实时计算出循环水泵的不同运行方式下机组发电综合煤耗率,并以其为最终的优化指标,来确定循环水泵的运行方式,为循环水泵的优化运行提供理论依据,也为发电厂节能降耗带来经济效益。     

偏工况下气液两相离心泵喘振特性

当离心泵在小流量工况运行且传输介质为气液两相流时，含气率达到某一值时，会发生喘振现象，导致泵的扬程突降。本文采用计算流体动力学分析方法对一气液两相流离心泵进行了研究，通过对外特性曲线进行分析，发现了学者们所提到的喘振现象。为了提高离心泵在气液两相小流量工况下的水力特性，引入一种空腔结构，分析其对气液两相离心泵内部流场的影响及喘振的改善作用。结果表明：在气液两相喘振工况下，空腔结构可以改善叶片正背面的压力分布，均匀气液两相在叶轮流道中的分布，有效减轻离心泵的气堵现象。因此，空腔结构不仅在结构上可以平衡叶轮、减轻泵的整体质量，还可以减轻流场中气液分离现象，避免喘振的发生，提高泵的水力性能。     

On the possibility of connecting a non-operating main circulation pump with three pumps in operation without preliminary coast-down of power-generating unit No. 5 in the Novovoronezh nuclear power plant

The subject of this paper is a transient caused by connection of a standby loop to three operating circulation pumps at the initial reactor heat rate equal to 70% of the rated value without preliminarily reducing it to 30% of the rated level as required by the safe operation regulations. Failure of the following normal operation systems is supposed: the first- and the second-type warning protection systems, all quick-acting reducing devices releasing steam into the auxiliary manifold, the electric heaters of the pressurizer, the pressurizer injection system, the primary cooling circuit fluid makeup/blow-through systems, and the blocking systems to shut down the main circulation pump after the level in the steam generator is exceeded. In addition, it is supposed that, under transient conditions, the valves of the turbine regulation system will be in the position in which they were at the moment of the initial event until generation of the signal for positive closing of the turbine stop valves. The first signal to actuate the reactor emergency protection system (EPS) is skipped. The failure of all quick-acting reducing devices releasing steam into the atmosphere is assumed. In addition to equipment failure, at the moment when the main circulation pump is connected, the operator erroneously puts in a new setting to maintain the power allowable for four pumps in operation-in the calculations it was taken equal to 104% of the rated level at most considering the accuracy of evaluating and maintaining the reactor heat rate-and the working group of the reactor protection and control system (P&CS) starts moving upward. On reaching the set power level, the automatic reactor power regulator stops operating and the P&CS elements remain in the position in which they are at the moment. Compliance with the design safety criteria for the adopted scenario of the transient is demonstrated.     

锡林浩特二电厂调速给水泵的选择

针对锡林浩特二电厂2×25MW高压供热机组给水系统中给水泵的选择,为提高给水泵的经济性、节约厂用电,将给水泵在锅炉母管制给水系统中的三种并联运行方式和调节方法进行了分析,得出在母管制给水系统中装1台调速泵,使之和定速泵并联运行调节整个给水系统负荷,消除给水泵流量供需不匹配而造成母管压力过高的耗电损失,是一个投资少收效大的节能措施。是内蒙古电力系统母管制给水系统设计的首例。     

660 MW机组汽泵电泵并列运行的给水控制及RB策略

针对塔山电厂超临界660MW直流炉机组汽泵电泵并列运行的给水系统,采用“水跟煤”的控制策略,并通过中间点温度对给水进行修正。给水主控输出转速指令,通过折线函数形成电泵勺管控制指令,实现了汽泵、电泵并列运行,能够同时参与给水调节。针对汽泵RB,通过联启电泵并逐渐增大勺管开度,保证了给水流量的平稳下降,维持汽温的稳定。运行和试验结果表明,本控制方案对给水系统的控制能够保证机组的安全、稳定运行,在给水泵发生RB时可以稳定、快速地减负荷,使主参数平稳过渡。