The number of visits: Time
It issue January 16, the Vietnamese Communist Party the fourth Plenary Session of the 11th Party Central Committees central until <>Resolution, propose concentrating on developing traffic, supply of electric power, water conservancy and tackling climatic change, urban construction, ten pieces of key infrastructure field such as industrial area, economic zone, commerce, communication, education and training and scientific craft, health care, cultural tour and sports. The main content about infrastructure of supply of electric power is as follows:
According to the seventh electric development plan requirement in the country, finish every power plant station on schedule Construction, build the large-scale power plant with power of more than 1 million kilowatts of power generating preferably; Develop solar energy and wind-power electricity generation actively; Study and build the power station of the can holding type.
Would rather obey the nuclear power station No. 1 and 2 to construct, guarantee the first unit was put into operation in 2020. The power reach 10,700,000 kilowatts to make the nuclear power generate electricity by 2030.
Build and form a complete set and is defeated by and changed electric wire netting, accord with the construction scheduling of hydropower station. Study and build intelligent electric wire netting, adopt the advanced craft, raise the electricity and assign and transport efficiency. Realize Vietnam and this area surrounding countries is incorporated into the power networks.
1.The purpose to boil stove:
Because its heated surface of boiler installed newly is in charge of department’s collecting the intine of case and steam dome and oiling pollutant such as the rust, if does not go on before operation if dealing with, will enclose forming the hard deposit partly in the tube wall, lead to the fact the heat conduction coefficient of the heated surface is reduced. Thus influence the thermal efficiency of the boiler, another part will dissolve the quality influencing the steam in water, need, go on alkali boil the stove to boiler according to ” industrial the intersection of boiler erection and construction confirm technical specification “.
2.Boil the condition that the stove has already possessed:
A kind of moisture content of anaphase refractory brick mortar of baker is smaller than 7%
It is qualified to add medicine, pipeline and machinery of taking a sample and already all install finishing and already debugging.
Chemical water treatment and boiling already all preparation of medicines of the stove.
Every transmission apparatus including the lighting facilities in the factory building of the boiler In putting into operation normally state,
The attenbants of every part such as boiler, chemical analysis have already all got to the hillock.
3.Boil the stove craft:
1On baker later stage, a kind of moisture content of mortar is low in 7%, the water level plans to add medicines under bringing the water level down to the manhole door by blowdown.
2Boiler circulating water quantity is according to cube 100, add medicine quantity NaOH 300 kilograms, Na3PO4.12H2O 300 kilograms, mix and worthy of putting into the boiler into medicinal solution, add medicines in order to at one time add enough.
3Open to the water valve, give water to the stove, the full water on the boiler, it enables the water circulation of the stove to turn on the water circulating pump, boil the stove.
2Boil the stove to divide together 3 issues:
1Step up slowly, the steady voltage when the pressure of the steam dome reaches 0.5MPa, once of blowdown of boiler, hot urgent bolt
2Boil the stove at this pressure for 8- 12 hours, testing personnel separates for 4 hours and takes a sample and analyzes once each time, and inform the analysis result of to operate the persons who have.
3Monitor the water level tightly at the time of blowdown, strive to be steady, circulate tightly and waterproofly and destroy, and do the water level record well.
4Boil in the stove in first issue, demand, run personnel to the intersection of cigarette and warm, the intersection of cigarette and pigeonhole, temperature, water level and swell the intersection of person who point out,etc. and table check meter once two hour while being every.
The number of visits: Time
British government declares the small-scale regenerated energy power technology excluding the solar energy only bends over technology New rate for incorporation into the power network.
This bill would come into force on December 1, 2012, it will influence all new technology which is suitable for the rate for incorporation into the power network. The rate for incorporation into the power network of solar energy is replenished and already announced.
British energy and climatic change department DECC Announce the latest rate for incorporation into the power network is replenished, it postpones voluntary certificate ROCs of regenerated energy The final result released, it will set up the new pricing mechanism of large-scale regenerated energy from April of 2013.
Replenish according to the new rate for incorporation into the power network, detest oxygen to digest AD Introduce one decreasing mechanism, from the will it be April 2014 year, wind-powered electricity and water and electricity introduce these technology. The rate for incorporation into the power network of regenerated energy is replenished and announce two months ago.
The British energy minister Greg Barker says: ” I want to offer long-term financing for these small-scale green electric projects, it is not merely solar energy, the new rate for incorporation into the power network is replenished the bill to realize this recommends the goal. ”
An unusual noise
1When the stereo is bigger and noisier, it may be the question of the voltage transformer core. For example, while inserting one or compressing tightly the screw of the core to become flexible, the instruction of the instrument is generally normal, the color, temperature and oil level of the insulating oil do not have great change, should stop the operation of the voltage transformer at this moment, check.
2Insert the boiling sound with water in the stereo, send out ” Rumble ” Bubble ease speak,may winding to have troubles more serious, be made nearby part of it not generated heat to last oil gasification seriously. The contact of the shunting switch is badly and a bit more somely and serious and overheated or shorts out among voltage transformer circle, will all emit this kind of sound. At this moment, should stop the voltage transformer and run immediately, overhaul.
3Insert explosion sound in the stereo, at the time of the loud and irregularity, it may be that a device body of the voltage transformer is insulating to puncture phenomena. At this moment, should stop operating the voltage transformer, overhaul.
4Insert one that discharges in the stereo ” Creakily creakily ” When the, may voltage transformer device body or sleeve pipe take place superficial part discharge. If is a telescopic question, in the climate is abominable or at the night, can also see the aura of corona or blue, purple little spark, at this moment, should clear up the sleeve pipe superficially and dirtily and corruptly, and then spread coating such as silicon oil or silicon lipoprotein. At this moment, should stop the voltage transformer, check whether the earthing and distance to the ground of every electrification position core fulfils requirements.
5While inserting continuous, regular striking or friction sound in the stereo, it may be that some parts of voltage transformer cause machinery to keep in touch because the core is shaken, or because the unusual noise caused that the static discharges, and various measure tables and count pointing out and the temperature is reactionless, though this kind of noise is unusual, to run and has not endangered big, needn’t stop running immediately ing, can get rid of while planning to overhaul.
2 temperature anomaly
The voltage transformer is in a situation that load and heat-dissipating condition, ambient temperature do not change, higher with the temperature at the time of the condition than originally, and there is raised trend constantly, it was the temperature anomaly of the voltage transformer that rose, raise with the ultra terminal temperature likewise the trouble of voltage transformer symbolizes.
The raised reason of causing the temperature anomaly is as follows,
Short out among the voltage transformer circle, among layer, among burst;
The core part of the voltage transformer shorts out;
Leak megnetism or vortex cause the fuel tank, case lid,etc. to generate heat;
Cross and load running for a long time, the accident passes and loads;
The heat-dissipating condition worsens etc..
Find the temperature anomaly of the voltage transformer while running, after finding out the reason first, and then take the corresponding measure to get rid of, lower temperature, if is caused by trouble within the voltage transformer, should stop running, overhaul.
3 gushes out the oil and explodes
Ge that the trouble within the voltage transformerthe voltage transformer, should stop running,, continue electric protector, fail, cut off power in time again, make the intersection of trouble and longer time exist continuously, make the pressure within the body of the case increase continuously, the oil gas of the high pressure squirts and forms the accident from defending booster or other weak in intensity of body of case.
1It is damaged that insulating: Short out, wait for some to make insulating to damage while being overheated among the circle; The voltage transformer enters water to make insulatingly and is made moist damaging; Voltage of striking by lightning etc. make insulating to damage, cause internal basic factor of short circuit.
2Break and produce the electric arc: Line group wire weld bad and lead wire connect factor of becoming flexible etc. might cause, break until large electric current bludgon into, breaking some produces the high-temperature electric arc to make oil gasification impel the internal pressure to increase.
3Adjust and press the trouble of the shunting switch: The adjusting and pressing one section of coils of high-pressure winding of voltage transformer of distribution is linked together by the shunting switch, the shunting switch touches the head to connect in the high-pressure winding return circuit, and short out in the electric current through the electric current of load with winding, if the intersection of shunting switch and sound touch hair to be hot, jump fire, get up arc, make it pigeonhole a coil, short out not to transfer.
4 serious oil spill
The seepage oil phenomenon is more general in the voltage transformer runs, the oil level is in the fixed range, can still continue planning to overhaul in running or arrangement. But the voltage transformer oil is serious in seepage, or is overflowing from the damaged place constantly continuously, the oil level is counted and can not already see the oil level, should stop operating the voltage transformer immediately at this moment, mend and leak and refuel.
When fluid flow through solid cliff side, fluid, and transmittance process of heat that go on shout between the cliff side The convection changes heat .
Utilize convection it changes hot apparatus to be more in power plant, exhaust gas flow through to flow through heat exchanger and hot exchange that tube wall take place for instance; In congealing vapour device, copper in charge of intine, cooling water and copper in charge of exterior wall and steam turbine arrange hot exchange that take place among the vapour.
Influence the convection to mainly have five respects to change the hot factor:
Motive force that the fluid flows. There are two kinds of motive force that the fluid flows: One kind flows freely; One kind forces to flow. Force to flow and transfer to hotly and flow, transfer to than freedom usually hotly stronger.
Whether the fluid changes. It is comparing with the time of becoming stronger that the convection that generally speaking has on the same kind of fluid when becoming changes heat.
Flow state of the fluid. Flow, mix vigorously between the the intersection of fluid and every part when the turbulence, when the turbulence, heat exchanges more strongly even more than at the time of laminar flow.
The geometirc factor influences. The relative position among the shape, size, fluid and solid of solid surface that the fluid is exposed to influences the convection to change heat.
Physical property of the fluid. The density, viscidity, heat conduction coefficient, specific heat of different fluids hold, vaporize the latent heat etc. differently, it is influencing the hot exchange of fluid and solid cliff side.
Note: The material divides solid state, liquid state, gaseous three phases, it refers to its change of state to change.
Electronic information technology makes the operational efficiency of the modern society reach the unprecedented intensity, also make the city more gorgeous. The information apparatus represented by computer has already become indispensable office equipment of all trades and professions, various advertising lights, LED reject and become indispensable decorating on the building. But the crisis hidden in this beautiful and brilliant high buildings and large mansions is seldom paid close attention to.
According to department’s report of public security men’s fire control, the proportion of the electric fire rises sharply in recent years. This use dense integral relation with electric energy in a large amount. The electric energy, as a kind of traditional energy, the respect that people are controlling it should already follow one’s bent, why seem unable to do what one wishes in recent years? This is because we use the way of the electric energy to change basically, therefore has caused some characteristics of the electric circuit to change. Most people have not known to this kind of change yet, so present the fault in controlling electric energy.
Difference of traditional load and modern load
The greatest difference between traditional electric load and modern electric load lies in, the former does not produce the harmonic electric current while working, the latter produced the harmonic electric current while working. The harmonic electric current is polluted of a kind of electricity, it will cause pollution to the electric wire netting. We make a metaphor to make ordinary readers easy to understand these concepts. The traditional traffic means of transport are holding the strength car, the modern traffic means of transport are cars. Holding the strength car will not discharge the exhaust, the car will discharge the exhaust, forms pollution to the air. The electricity that the harmonic electric current causes is polluted and correspondent to the air pollution that the car exhaust causes.
What kind of apparatus produces the harmonic electric current while working on earth? It is mainly a Hi-Tech electronic apparatus, for example electronic information apparatus, video monitoring system, LED rejecting, electricity-saving lamp,etc. such as the computer. This is because the harmonic electric current mainly commutates the circuit and produces, and any electronic apparatus includes commutating the circuit. Commutating the circuit will produce the harmonic electric current while working, just as discharge the waste gas when the gasoline engine work.
Because of the appearance of the harmonic electric current, some power consuming general knowledge in the past of people was no longer correct, among them it is the change of electric current of Line zero that the biggest one is different. In the distribution system, the circuit is divided for the battle line looks thread With Line zero. The traditional electrician’s theory thinks, when three-phase load is balanced, a electric current on the line is zero. ” Line zero ” This term is probably to come therefrom. So, traditionally, during electric design and construction, will reduce the sectional area of Line zero. However, when electric load is a modern electronic apparatus, this theory has been subverted completely. When load is an electronic apparatus ,” Even three-phase load is balanced, a electric current on the line is not zero either, will reach 2 times of the line electric current of looks instead ” .
This is a surprising conclusion. Because zero have too big electric current will lead to the fact the intersection of Line zero and overheated conductor on the line. From basic physical knowledge, we know, when the electric current on the conductor in fact reach 2 times of the electric current, the caloric value of conductor is 4 fold! Can think of but the cicada in consequence, this is a serious fire hidden danger.
Time bomb that the harmonic electric current buries
The appearance of the harmonic electric current, will cause a electric current on the line to exceed the electric current of the line of looks. Readers should pay attention to, the too big danger of electric current of Line zero is far greater than the too big danger of electric current of line of looks. This mainly has two reasons.
First of all, as everybody knows, once electric circuit exceeds specified load, will generate heat seriously, form the fire. So people have installed some to cross and flow the protector on the circuit for being safe. When the electric current on the circuit exceeds the specified value, cross and flow the protector and cut off the circuit automatically, have avoided the emergence of the fire. However, stipulate on the electric installation norm, not on Line zero installation flow to protect putting. So, when a electric current on the line is too big, there is not any protector movement, can only let, generate heat, will bring out the fire while burning the condition to possess.
Secondly, in the existing building, some Line zero has adopted the conductor more detailed than the line of looks, then contain greater fire hidden danger when a electric current flowing through on the line exceeds the line of looks.
20 years ago, it is about equal now that the electronic apparatuses of American-European countries popularized intensity and us, a lot of buildings were baffled and on fire at that time, people realized this phenomenon through the deep investigation. They have already strengthened the size of Line zero when the electricity has constructed now.
Get rid of the time bomb with NBF
With a large amount of popularization of the electronic apparatus, the danger that the harmonic electric current causes is serious day by day. The quality experts of electric energy have thought a lot of methods reduce the harmonic electric current. Among them, it is a method with supreme cost performance to use NBF.
The Chinese name of NBF is named ” The harmonic electric current blocking device of Line zero ” . This kind of apparatus has been employed in American-European countries extensively since the 1990s of last century. Main reason, the 1990s, American-European countries begin a large number of the intersection of popularization and the intersection of information and apparatus, economize on electricity apparatus, these apparatuses have caused the polluting seriously of electric wire netting and electromagnetic environment, among them the most serious consequence is that the electricity fire frequently takes place. People passed deep analysis, found at last that caused the root of the trouble of these question, it is the harmonic electric current! NBF is the apparatus emerging in order to dispel the harmonic electric current.
The subject worker group the second of the spaceflight studies 706 institutes, begin to study the electric energy quality problem from the eighties of last century, have made a contribution to ensuring the completion of the spaceflight task. In recent years, begin to apply space technology to national economic construction. The harmonic electric current problem caused to the electronic apparatus has been further investigated, and succeed in developing the harmonic electric current blocking device of NBF Line zero, the level reaches the international most advanced level.
The operation method of NBF is very simple, so long as the series connection is installed on Line zero, can dispel the fire hidden danger that electric current of Line zero over brings. For example, one software company, there are over 400 computers, splits on the three-phase distribution line, electric current of every looks is probably 120A, but the Line zero electric current is close to 200A. The administrative department of the property thinks this is a serious potential safety hazard, demand to rectify and improve. Through surveying and studying, someone has recommended using the scheme of the active wave filter. However, the high price of the active wave filter becomes the subject problem. Under the introduction of professional personnel, adopt NBF, has obtained the ideal result, Line zero electric current is reduced from nearly 200A to 50A, have dispelled the hidden danger of the fire.
NBF not only can dispel the fire hidden danger that electric current of Line zero over causes, can dispel other danger that the harmonic electric current brings. Can improve the electromagnetic environment that work in the environment greatly through installing NBF, promote the health.
The harmonic electric current produces stronger electromagnetic radiation, make the space full of magnetic fields of low frequency. The human body will present some uncomfortable phenomena in the magnetic field of low frequency for a long time, such as the common subhealthy state, comprising: Often can appear sleepy, tired, insomnia, the intersection of muscle and ache, the intersection of mood and symptom such as being unstable.
It is a kind of carcinogen that World Health Organization has already belonged to the electric magnetic field of low frequency together with benzene alkene, electric welding smog now. WHO international cancer research institutions and WHO thematic work groups think, the magnetic field of low frequency relates to children’s leukemia and brain cancer through assessing, exposing the intensity in the magnetic field exceeds 0.3
摘 要：供给同步发电机励磁电流的电源及其附属设备统称为励磁系统。它一般由励磁功率单元和励磁调节器两个主要部分组成。励磁功率单元向同步发电机转子提供励磁电流;而励磁调节器则根据输入信号和 给定的调节准则控制励磁功率单元的输出。为保证我厂 1000MW 发电机组安全运行，特别是采用了新型励磁 调节器，对我们的安全运行及维护又提出了新的要求，因此，必须详细了解励磁系统中励磁调节器相关知 识。
#13、 #14 号发电机励磁系统采用的是机端自并励静止励磁系统， 励磁调节器为瑞士 ABB 公司原装产品，其型号为 UNITROL 5000 系列 Q5S-O/U541-S8000。发电机静止励磁系统通过 可控硅整流桥控制励磁电流，达到调节同步发电机电压和无功功率的目的。
1励磁变压器; 2励磁调节器AVR3可控硅整流器 ; 4起励和灭磁单元; 励磁模块A10，A20中有：
每一块 COB 包括以下功能：
自动电压调节器自动控制， 励磁电流调节器手动控制 ，具有时间可调的软启动功能， 自动运行通道和自动备用通道之间的自动跟踪， 自动和手动通道的双向自动跟踪， 恒无功或恒功率因素的控制， PSS 电力系统稳定器，
b测量单元板MUB：用于测量发电机定子侧信号。它直接测量发电机的三相电压和电流， 并通过这些量计算出其它信号：如 P、Q、f 等，同时提供了强电参数和测量信号之间的电气 隔离。
c扩展门极控制板EGC ：作为双通道配置的后备通道使用。EGC 连同 COB、MUB 一起安装 在同一个金属箱中，但在结构上是独立的。
励磁电流调节， 通道跟踪，以便在 COB 故障时实现平稳切换 ，备用瞬时过电流保护继电器， 备用反时限过电流继电器 ，直流侧短路保护
16 位输入，带光耦合器，额定 24VDC ，控制输入电源来自内部 电源模块。 18 个输出继电器，带转换触点，用于状态显示和报警。 4 个多目的模拟输出
摘要: 风电场建设需要进行宏观和微观选址, 在一个较大的区域内综合考虑风能资源、联网条件、地形地貌和交通运输等条件, 选择出适合风电场建设的小区域, 再对该区域进行风资源评估, 确定每台风机的位置, 以取得风电场最大的年发电量和最佳经济效益。结合某风电场的实例, 对风电场选址和风机优化排布实用技术进行了探讨。
0 引 言
风能作为一种可再生的清洁能源, 越来越受到重视。开发风能已经成为解决能源和环境问题的一个重要选择。根据国家发改委可再生能源中长期发展规划, 中国风电装机规划目标2020年达到3 000万kW。实际上, 近几年中国风力发电事业高速发展, 2005年当年装机5013万kW, 增长6516%, 是全世界增长率最高的国家[ 1] 。
在风电场的建设中, 场址的选择极为重要,风电场场址选择的质量, 直接关系到投运后风电场的年发电量和经济效益, 本文对风电场的选址和风机优化排布工作进行了探讨。
风电场的经济效益取决于风能资源、联网条件、交通运输、地质条件、地形地貌和社会经济等多方面复杂的因素, 风电场宏观选址[ 2, 3] 是对一个较大地区进行上述条件的综合评估, 选择出一个风能资源丰富、且最有利用价值的小区域的过程。
建设风电场最基本的条件是要有能量丰富、风向稳定的风能资源, 选择风电场场址时应尽量选择风能资源丰富的区域。根据中国风能情况, 一般规定有效风速范围为3~ 25 m / s, 将风能丰富区规定为10m高度年平均风速在6 m / s以上, 50m 高度年平均风功率密度大于200W /m2, 年有效风速小时数大于5 000 h[ 4] 。可利用有关部门绘制的风能资源分布图进行宏观选址, 重点关注其中风能资源丰富区域。
影响并网风电场最大安装容量的因素包括系统网架结构、常规机组的旋转备用水平、系统常规机组的优化调度、负荷特性、机组的类型和分布及风电场的无功补偿状况等[ 5] 。风电场场址选择时, 应尽量靠近合适电压等级的变电站或电网以减少线损, 并网点短路容量应足够大。
尽量利用现有公路, 选择附近交通方便的场址以节约道路投资, 场址地形应尽量简单以利于大规模开发和大型设备的运输安装。
选址时, 应避开地震带和水文地质情况复杂的地区。对地貌分析可利用1B5 000地形图和卫星观测图, 判别并尽量选择具有较高平均风速的地形地貌如高原、山峰等, 尽量避开较低平均风速的地形地貌如盆地和森林等粗糙度较大的区域。
结合国家风电发展规划和各项环保要求, 在西北、华北、东北和东南沿海大规模开发风电。风电场选址时, 与居民区保持适当距离以减小噪音污染, 国家有关规范要求风电机组距居民区的最小距离应使居民区的噪声小于45 dB; 避开自然保护区等区域并尽量少占用耕地和破坏森林; 同时考虑各类极端气象条件的影响。
风电场微观选址是在宏观选址得到的小区域内, 确定每台风机的位置, 以使整个风电场获得最大年发电量, 尽可能降低施工成本的过程。
风资源评估需要对现场实测数据进行处理和修正, 并计算平均风速、空气密度、有效风能密度、风速的频率分布风频、风速持续时间分布、风能玫瑰等风资源数据[ 6] 。
目前中国通用的风能资源评估软件是WA sP,在欧洲平坦地形下, 该软件是一种较好的风资源评估工具, 具有较好的功能, 但对于复杂地形,该软件就很难准确估算复杂地形下的风资源状况,该软件在坡度大于5b时, 即出现计算误差, 在坡度达到17b时, 其计算结果基本就不可信, 但其计算结果仍可以作为重要参考。
掌握风电场风能资源的分布后, 进行风机的排布。在平坦地形区域对风能方向集中、主次风能方向基本呈180b的风电场, 按照8倍和5倍的原则进行风机的排布, 即风机的间距取叶轮直径的5倍, 风机的排距取叶轮直径的8倍, 风机的排与主风能方向垂直, 且风机前后错开, 呈梅花状排布; 对于风向较分散、主风能方向不明显的风电场, 一般按10倍7倍原则进行风机布置。
在丘陵和低山地形区域进行风机排布时, 采用W indfarmer软件进行风机布置的优化。一般应测量风电场1B5 000地形图, 在风电场范围, 禁止区域、噪音、阴影闪烁等限制条件下, 采用修正Park尾流模型对风机的布置进行优化。在风机优化时, 应设定风机的最小间距, 以应对风向的年际变化。
之后根据优化结果进行现场踏勘, 对风机位置进行微调, 使软件布置每台风机的机位都具有较好的施工条件。对于风能资源好、施工难度较大的机位应进行经济分析和计算, 以确定该机位的取舍。根据风电场的上网电价, 确定风电场单台风机的最低发电量, 对于发电量低于该数值的风机位置, 应进行调整, 并利用GPS 采集每台风机的坐标信息, 将风机坐标返回W indfarmer中并采用黏性漩涡尾流模型计算风电场年发电量,或将风机坐标返回WAsP 中计算风电场年发电量。
1 风能资源。风电场测风塔高度为27 m,根据前期现场实测数据, 计算出该地区27 m 高度处平均风功率密度为1 259W /m2。图2为风速的威布尔分布曲线, 其中参数为: 形状参数A =1114, 尺度参数k = 1192; 年有效风速 3 ~ 25m / s 利用小时数7 825 h, 风能资源丰富; 风电场的主风向为西南和西北风, 相对稳定、集中,有利于风电机组布置。
2 交通运输和施工条件。该风电场区域附近有公路和铁路可以用于设备运输, 风电场所处区域为丘陵, 海拔高度400 m 左右, 地形起伏和坡度均较小, 有利于大型设备的运输和安装。
3 地质和地形地貌。风电场区域为丘陵区域, 水文地质结构简单; 地表有少量树木覆盖, 地表粗糙度较小; 风电场覆盖丘陵的西北坡和顶部, 面向主风向, 地形对风具有加速作用;丘陵的西南坡风资源丰富且面对主风向, 但相比西北坡坡度较大, 施工难度较大, 不利于大型设备安装, 因此不选择这块区域。
4 其他因素。在丘陵的顶部和东南坡有大片森林, 因此在规划风电场范围时, 将风电场设置于森林之外以尽量避免破坏森林; 风电场距离居民区遥远, 容易满足规定的噪音要求。
1 风资源评估。使用WA sP对该风电场进行风资源评估, 得到区域内46 m 高度风功率密度分布图和年平均风速分布图, 分别如图3、图4所示, 图中虚线框内为宏观选址阶段规划的区域。
In the pipeline of pressure, because of the rapid change of the liquid velocity of flow, thus cause the liquid pressure in the tube to change prominently and repeatedly and rapidly, to there is one kind in the pipelining ” The hammer is hit ” Characteristic,call water hammer this kinds of phenomenon or ask water not to be hit .
Water hammer has straight water hammer and difference of shouldering water hammer, their danger is as follows,
Straight water, at the hammer, pressure in the pipeline rise, can in order to exceed normal dozens of time to odd one hundred time of pressure in the tube, so that the tube wall produces very large stress, and the repeated change of pressure will cause the vibration of pipeline and apparatus, the reversal of stress of the pipeline changes, will cause the damage of the pipeline, pipe fittings and apparatus.
While shouldering water hammer, the pressure in the pipeline is reduced, it will cause pipeline and apparatus to shake to offer. Hand in and pass changing in stress, have unfavorable influence on apparatus, while shouldering water hammer at the same time, if the pressure is lowered may produce the unfavorable vacuum in the tube to cross low, under the function of the ambient pressure, will squash the pipeline.
In order to prevent the appearance of water hammer phenomenon, can adopt and increase the valve to get up and close time, try hard to shorten the length of the pipeline, install the safe valve or air room on the pipeline, in order to limit the pressure raised number value or number value that the pressure was lowered too low suddenly.
Park the intersection of pump and the intersection of water and hammer, might cause pump station and input the intersection of water and system, happen serious accident if the intersection of pump house and inner apparatus or pipeline break, lead to the fact the pump house to flood, it causes accumulated water of house on the way that the stylograph breaks ,So the detailed conditions of the necessary foundation take the corresponding measure to dispel and stop the pump water hammer or subdue water hammer pressure.
1Reduce the velocity of flow which inputs water pipeline, can reduce water hammer pressure to a certain extent, but will increase the pipe diameter of the stylograph, increase the investment of project.
2Should consider trying hard to avoid the hump or slope drastic change while fixing up while inputting water pipeline.
3Through simulation, select for use and rotate inertia GD2 heavier water pump assembly or add the flywheel equipped with enough inertia, can reduce water hammer value to a certain extent.
4Set up water hammer and dispel the device
Adjust and press the room: It is a water tank of a steel or armored concrete, adjusting and pressing the room to adjust and press two kinds of rooms to adjust and press the room unidirectionally and bidirectionally on the pressure pipeline.
Atmospheric pressure pot: There are few China’s use experiences, Britain abroad It is relatively extensive to use. It utilizes gas volume and particular law work in the pressure. The atmospheric pressure of varying with pressure in the pipeline pot mends water or absorbs the too high pressure in the pipeline to the pipeline, its function and adjusting and pressing the tower similarly bidirectionally
Water hammer dispelling device: Water hammer dispelling device can be in case of not needing to prevent the fluid from flowing, dispel fluid all kinds of effectively hammer and the intersection of wave and irregular ink taken place to well up hit the wave and shake outside water that transmission system might produce, thus reach and dispel the destructive shock wave, get up to the purpose to protect. Once adopted far and wide before the eighties. It installs the function that some water hammer dispelling devices have not reset automatically near the check damper, it is easy because misoperation causes and takes place water hammer.
Close the check damper slowly: There are the heavy hammer type and two kinds of energy-storages. This kind of valve can close time to valve to adjust within the specific limits according to the need. Generally the valve in 3- 7 s closes 70%- 80% after power cut, closing time and regulating according to the situations of water pump and pipeline of 20%- 30% of surplus, generally in 10- 30 s range. Can utilize the best time of computer simulation, and debug and fix live. What merits attention is, when the hump exists and make water hammer up in the pipeline, the function of closing the check damper slowly is very limited.