Created on:2021-08-03 15:06

Hydraulic fault diagnosis and maintenance of hydropower equipment_ Parameter principle of hydraulic equipment of hoist

水电设备液压故障诊断与维修_ 启闭机液压设备参数原理
Hydraulic fault diagnosis and maintenance of hydropower equipment_ Parameter principle of hydraulic equipment of hoist

    某电厂电站安装有6台55万千瓦的水轮发电机组,总装机容量330万千瓦,保证出力100万千瓦,多年平均发电量为170亿千瓦时。电厂大坝为双曲拱坝,由于河谷狭窄、水头高、流量大,因此,泄洪设施成为该水电站枢纽中的重要组成部分。电厂泄洪建筑物按千年一遇洪水流量20600m3/S设计,5000年一遇的洪水流量23900m3/s校核。主要泄洪设施包括表孔、中孔、泄洪洞。
A power plant is equipped with 6 sets of 550000 kW hydro generator units, with a total installed capacity of 3.3 million KW, a guaranteed output of 1 million KW, and an average annual power generation of 17 billion kwh. The power plant dam is a double curvature arch dam. Due to the narrow valley, high head and large discharge, the flood discharge facilities become an important part of the hydropower project. The flood discharge structure of the power plant is designed according to the flood discharge of 20600m3 / s with a return period of 1000 years and checked according to the flood discharge of 23900m3 / s with a return period of 5000 years. The main flood discharge facilities include surface outlet, middle outlet and spillway tunnel.

    表孔沿拱坝顶部呈径向布置,孔口尺寸为11m×11.5m(宽×高),堰顶高程1188. 5m,7个表孔在设计洪水位时泄量为6260m3/s,校核洪水时泄量达9500m/s。表孔闸门形式为弧形门,闸门的启闭采用2×1000kN的双缸液压启闭机进行操作。
The surface holes are arranged radially along the top of the arch dam, and the hole size is 11m × 11.5m (W) × The weir crest elevation is 1188.5m. The discharge capacity of the seven surface outlets is 6260m3 / s at the design flood level and 9500m / s at the check flood level. The form of surface outlet gate is radial gate, and the gate is opened and closed by 2 × 1000KN double cylinder hydraulic hoist.

(1)设备参数
(1) Equipment parameters

该水电站表孔2×100t液压启闭机用于操作表孔11×12-12m的弧形工作门。液压启闭机由液压缸、支铰座、液压系统总成、闸门开度仪、行程控制装置、液压管路及附件组成。每孔液压启闭机布置有1套液压泵站、两套液压缸,液压泵站位于闸门孔口右侧闸墩1202.20m高程上的液压泵室内。该系统工作制为一用一备,即一台泵组工作,一台泵组备用,并能自动切换。表孔液压启闭机主要参数如下表所示。
The hydropower station surface hole 2 × The 100t hydraulic hoist is used to operate the surface hole 11 × 12-12m arc work door. The hydraulic hoist is composed of hydraulic cylinder, hinge support, hydraulic system assembly, gate opening meter, stroke control device, hydraulic pipeline and accessories. Each hydraulic hoist is equipped with a set of hydraulic pump station and two sets of hydraulic cylinders. The hydraulic pump station is located in the hydraulic pump room on the 1202.20m elevation of the pier on the right side of the gate orifice. The working system of the system is one for use and one for standby, that is, one pump unit works and one for standby, and can be switched automatically. The main parameters of surface hole hydraulic hoist are shown in the table below.

 

表孔液压启闭机主要参数
Main parameters of surface hole hydraulic hoist

启门力/t
Door opening force / T

2×100

 

无杆腔工作压力/MPa

1.5

闭门力

闸门自重

 

液压泵额定压力/MPa

28

液压缸工作行程/m

7.05

 

液压泵额定流量/(L/min)

72.7

(启/落门速度)(m/min)

0.68

 

闸门自重/t

64.5

杆腔最大工作压力/MPa

16.84

 

孔口尺寸/(l/min)

11×12.5

杆腔流量/(L/min)

4

 

无杆腔流量/(L/min)

62

工作行程/m

7.05

 

全行程/m

7.3

 

(2)工作原理
(2) How it works

基本控制回路参考图U。
Refer to figure u for basic control circuit.

U.jpg

    ①空载启动启动液压泵电机,此时各电磁换向阀均未得电,处于图示位置。主油路进入3-DN25母管,从3-DN25母管上分出四条控制油管(虚线),从右向左,第一条控制油路经过阻尼孔、单向阀、DT5、DT2回油箱;第二至第三条控制油路各通过DT2、DT6,进入盲孔;第四条控制油路经DT1、梭阀作用在插装阀16.1上,使其产生背压,导致主油路不能打开此阀。由于第一条控制油路呈现无压状态,它对插装阀17.1后产生不了背压,则主油路克服插装阀17.1后的弹簧力(开启压力在0.03~0.4MPa),将其阀芯打开,并通过预压单向阀、回油滤油器进入油箱,实现空载启动。
① Start the motor of the hydraulic pump with no load. At this time, all the solenoid directional valves are not powered on and are in the position shown in the figure. The main oil circuit enters the 3-dn25 main pipe, and four control oil pipes (dotted lines) are separated from the 3-dn25 main pipe. From right to left, the first control oil circuit passes through the damping hole, one-way valve, DT5 and DT2 oil return tank; The second to third control oil passage respectively passes through DT2 and dT6 to enter the blind hole; The fourth control oil circuit acts on cartridge valve 16.1 through dt1 and shuttle valve to produce back pressure, which makes the main oil circuit unable to open the valve. Since the first control oil circuit is in non pressure state, it can not produce back pressure to cartridge valve 17.1, then the main oil circuit overcomes the spring force behind cartridge valve 17.1 (the opening pressure is 0.03 ~ 0.4MPa), opens its valve core, and enters the oil tank through pre pressure check valve and oil return filter, realizing no-load start.

    ②闸门开启 空载启动25s后DT1、DT2得电,在3-DN25母管上的控制油路从右向左,第一条经阻尼孔、单向阀DT5、换向后的DT2,最后与第二条控制油路连通(高压油),同时此油还作用在插装阀16.2及17.1上,使其产生背压;第三条控制油路仍然经DT6进入盲孔;第四条控制油路经换向后的DT1进入盲孔,使插装阀16.1后无背压。至此,系统中的三个插装阀的状态为17.1关闭、16.1导通、16.2关闭;系统的压力由压力盖板18.1内的溢流阀决定。这样主油路经插装阀16.1分流后经左右缸的调速阀分别进入液压缸下腔。液压缸上腔回油经预压单向阀6.1回油箱。至此启门过程结束。
② After the gate is opened and started without load for 25 seconds, dt1 and DT2 are powered on. The control oil circuit on 3-dn25 main pipe is from right to left. The first one is connected with the second control oil circuit (high pressure oil) through damping hole, check valve DT5 and DT2, and then acts on cartridge valves 16.2 and 17.1 to generate back pressure; The third control oil circuit still enters the blind hole through dT6; The fourth control oil circuit enters the blind hole through the reverse dt1, so that there is no back pressure behind the cartridge valve 16.1. So far, the states of the three cartridge valves in the system are 17.1 closed, 16.1 on and 16.2 closed; The pressure of the system is determined by the relief valve in the pressure cover plate 18.1. In this way, the main oil circuit is divided by cartridge valve 16.1 and then enters the lower chamber of the hydraulic cylinder through the speed control valves of the left and right cylinders. The return oil from the upper chamber of the hydraulic cylinder returns to the oil tank through the preloading check valve 6.1. At this point, the door opening process is over.

    ③闸门关闭表孔闸门是靠自重下落的,系统只需将液控单向阀打开即可实现闸门下落。液压泵同样空载运行25s后DT5、DT6得电,控制油路第一条经阻尼孔、单向阀、换向后的DT5作用于10MPa溢流阀上,系统压力由此确定为10MPa,同时控制油还作用在插装阀17.1上,使其产生背压;第二条经DT2进入盲孔,使插装阀16.2无背压;第四条经DT1、梭阀作用在插装阀16.1上,使其产生背压;第三条经换向后的DT6、单向节流阀直接作用在左右缸下腔的液控单向阀上,并将其打开。此时三个插装阀的状态为17.1关闭、16.1关闭、16.2打开。液压缸下腔回油经单向阀、调速阀、插装阀16.2、17.1进入上腔。液压缸上腔与下腔的容积差通过自吸的方式从油箱中补油。
③ When the gate closes, the surface outlet gate falls by its own weight. The system only needs to open the hydraulic control check valve to realize the gate falling. DT5 and dT6 are powered on after the same no-load operation of the hydraulic pump for 25s. The first control oil circuit acts on the 10MPa relief valve through the damping hole, one-way valve and DT5 in reverse direction, and the system pressure is determined as 10MPa. At the same time, the control oil also acts on the cartridge valve 17.1 to produce back pressure; The second one enters the blind hole through DT2 to make cartridge valve 16.2 have no back pressure; The fourth one acts on cartridge valve 16.1 through dt1 and shuttle valve to produce back pressure; The third dT6 and one-way throttle valve directly act on the hydraulic control one-way valve in the lower chamber of the left and right cylinders and open it. At this time, the states of the three cartridge valves are 17.1 closed, 16.1 closed and 16.2 open. The return oil from the lower chamber of the hydraulic cylinder enters the upper chamber through the check valve, speed regulating valve and cartridge valve 16.2 and 17.1. The volume difference between the upper chamber and the lower chamber of the hydraulic cylinder is filled from the oil tank by self-priming.

    ④闸门纠偏闸门纠偏是对液压缸位移进行直接检测,并通过电液闭环实现旁路纠偏。纠偏回路由接入液压缸下腔的单向节流阀及三位四通电磁换向阀组合而成。纠偏原则:在启门过程中,哪一缸的速度快(即流量大),则将哪一缸下腔的油通过旁路纠偏回路放掉一部分,减小此缸的进油量,即降低此缸的运行速度,以达到与另一缸的同步;落门时相反,哪一缸的速度快,则将另一缸下腔的油放掉,增加另一缸的排油量,以达到与这一缸韵;回步。具体执行情况为:启门过程中,如果左缸速度快,超出系统允许偏差,则DT3动作,左侧液压缸下腔的油通过单向节流阀、换向后的换向阀、插装阀16.2、17.1进入油箱;当落门过程中,如果左缸速度快,则DT4动作,将右液压缸下腔的油通过单向节流阀、换向后的换向阀、插装阀16.2、17.1进入油箱。总之,现场只需根据闸门左右缸当前的实际开度值的大小(无论启门还是落门)来判断并纠偏。
④ The gate deviation correction is to directly detect the displacement of the hydraulic cylinder, and realize the bypass deviation correction through the electro-hydraulic closed loop. The rectifying circuit is composed of a one-way throttle valve and a three position four-way electromagnetic directional valve connected to the lower chamber of the hydraulic cylinder. Deviation correction principle: in the process of opening the valve, if the speed of the cylinder is fast (i.e. the flow is large), the oil in the lower chamber of the cylinder will be discharged through the bypass deviation correction circuit to reduce the oil intake of the cylinder, i.e. the running speed of the cylinder will be reduced, so as to achieve synchronization with the other cylinder; On the contrary, if the speed of one cylinder is fast, the oil in the lower chamber of the other cylinder will be discharged, and the oil discharge of the other cylinder will be increased to match the speed of the other cylinder; Step back. The specific implementation is as follows: in the process of opening the valve, if the speed of the left cylinder is fast and exceeds the allowable deviation of the system, DT3 will act, and the oil in the lower chamber of the left hydraulic cylinder will enter the oil tank through the one-way throttle valve, reverse direction valve, cartridge valve 16.2 and 17.1; In the process of door falling, if the speed of the left cylinder is fast, DT4 will act, and the oil in the lower chamber of the right hydraulic cylinder will enter the oil tank through the one-way throttle valve, reversing valve, cartridge valve 16.2 and 17.1. In a word, the site only needs to judge and correct the deviation according to the current actual opening value of the left and right cylinders of the gate (whether the gate is opened or dropped).

    ⑤闸门自动复位闸门长时间全开时,为防止因液压系统泄漏引起闸门下沉而影响运行,在工作回路中设置了闸门下沉自动回升功能。当闸门从开肩位置下滑,下滑量达200mm时,行程控制装置指令工作液压泵启动(自动泵启动,若自动泵故障,控制系统将自动切换至备用泵启动),使门复位,同时发出报警信号;若备用液压泵电动机组或液压系统故障,闸门复位失败,闸门继续下滑,下滑量达205mm,行程控制装置再次指令备用泵肩动,并向值班室发出紧急报警信号。
⑤ When the gate is fully opened for a long time, in order to prevent the gate from sinking due to the leakage of the hydraulic system and affect the operation, the automatic rising function of the gate sinking is set in the working circuit. When the gate slides from the open shoulder position and the sliding amount reaches 200 mm, the travel control device commands the working hydraulic pump to start (the automatic pump starts, if the automatic pump fails, the control system will automatically switch to the standby pump to start), so as to reset the gate and send out the alarm signal at the same time; If the standby hydraulic pump motor set or hydraulic system fails, the gate reset fails, and the gate continues to slide down by 205mm, the stroke control device instructs the standby pump to move again, and sends an emergency alarm signal to the duty room.

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