[Summary ] direct the intersection of 600MW and coal-fired the intersection of aircrew and electric the intersection of dust remover and characteristic against, combine pairs of the intersection of sleeve pipe and turbulent strength, fail gray technology and run question appeared to debug, compare to different design, disposition which lose the gray system,etc., have proposed the system optimization scheme. The dirt-removing system of doing the electric dust remover of 600MW coal-burning boiler aircrew of practice sums up as 2 kinds of models and designs according to running, make the gray system of failing dispose and standardize.

[The keyword ] strength is sent One pair of sleeve pipes Optimization

0 foreword

With the development of power system, 600MW precritical, supercritical aircrew already become the main aircrew of the Chinese power industry, according to China ” Eleven five ” Plan, will form the ability to produce large-scale thermal power generating equipment at the end of 2010, among them 600MW aircrew realizes and produces in enormous quantities, it is not lower than 25 to go into operation in the aircrew every year. To the electric dust remover characteristic of 600MW common coal-fired aircrew, combine pairs of the intersection of sleeve pipe and turbulent strength fail gray technology succeed in, employ and design question that appear debug, in a plurality of power plant, design, dispose etc. comparing to the gray system of failing, carry on rational distribution to the system and save energy and reduce the cost.

Dispose and involve the factor in a design systematically

1. An electric dust remover fixes up the characteristic

As the requirement for environment protection is improved, the electric dust remover of 600MW coal-burning boiler aircrew is generally one pair of electric fields of room five, 40 pieces of dust are 5×8 ,Assign one to transport the pot under each hod. Design and exert oneself generally in 100- 150t/ h. Because boiler firing method, assigning the formal difference, generally speaking the coal device of province sets up 6- 7 hods, the air preheater sets up 4 hods, it is roughly 1- 2t/ h to exert oneself, but does not set up the hod under specific coal device of boiler province, empty pre- device.

1. 2 does the gray conveyer system and designs fixing up the consideration

1. 2. A thick, detailed dust divides the question, generally leave an electric field the dust is regarded as the thick dust, two, three, four, five electric field dust is the thin dust. But there are power plants that require that defines it as thick dust in two electric field coal ash thickness dust divides, so, should define the design conveyer system according to the power plant’s own requirement, market demand.

1. 2. 2 stability of running out of the system, reliability consideration. Such as the spare problem of other electric fields under a certain electric field trouble stoppage in transit situation.

1. 2. The development environment of grey market of 3 power plants of coal, thick dust, detailed gray price question choose the systematic disposition, or consider whether the system disposes the dust and sorts the device.

Download the intersection of full text and the intersection of 600MW grade and coal-fired the intersection of aircrew and pairs of sleeve pipe fail gray system dispose way optimize.pdf

Summary: Have unusually made deep summary analysis to the voltage return circuit which 110kV transformer substation 10kV system often presents, make detailed introduction on the intersection of voltage and trouble form that return circuit appear in the past, and provide and handle the scheme, in order to improve systematic power supply reliability, there is certain value on real work.

Keyword: Several respects such as the voltage return circuit anomaly that the transformer substation takes place, operation way and treatment of trouble of 10kV system carry on the discussion.

2 10kV systematic kind and treatment method unusual in voltage

In general, it can be divided into two kinds that 10kV voltage return circuit is unusual, namely 10kV voltage a systematic trouble and 10kV voltage and two systematic troubles. Embodied in earthing earthing 10kV bus bar, breaking, 10kV circuit and high-pressure fuse wire of mutual inductor of 10kV voltage to fuse etc. as to the former, embodied in fuse wire two times of voltage to fuse as to the latter, connect the place and break etc. twice.

2. One, twice insurance fuse wire fuses

1The insurance fuse wire of once fuses and judges the voltage at first. Section I U. =3kV, Ub =6. 3kV, U =6. 3kV, 10kV system presents a preface voltage, earthing and newspaper section I bus bar, because ¨ is normal in voltage, this kind of situation can be basically judged to cause for the following two reasons: Break but not ground once. The high-pressure fuse wire fuses. Daily five three-phase column type voltage mutual inductors of our bureau, can observe and protect the voltage and measure the voltage in 10kV protector sampled value menu when the above-mentioned situation appearsing, the two should be the same. 3U0=U , because 10kV bus bar is from mainly turning into the low-voltage side, 10kV sleeve pipe is arranged and drawn by mother directly, it is possible not to almost break, so judge and fuse for 10kVTv high-pressure fuse wire.

Download the unusual treatment method discussion of return circuit of transformer substation 10kV systematic voltage of full text.pdf

The Summer Solstice just passed, the high temperature had already come. High-temperature weather, increase by 1,360,000 kilowatts within the 3 days such as load such as power consuming such as Beijing continuously, the greatest power consuming load of electric wire netting of Beijing reaches 11,840,000 kilowatts, create this year enter Xiaxin high, increase by 19.8% compared with the same period of last year.

According to the introduction of press spokesman of Beijing Utilities Electric Co. Tang RuHai, during summer has set in this year, will not present the apparatus overload and phenomenon of operating a switch to ration the power supply under the normal situation of the electric wire netting, predict it is about 14 million kilowatts that the peak load of the electric wire netting will reach, among them, the load of lowering the temperature will reach 5,500,000 kilowatts, account for 40% of peak load in the whole city.

It is reported, nearly 4000 agencies purchase the electricity, report for repairment in Beijing at present. Among them sell the electric wire netting and click and offer the incessant service in 55 24 hours.

Summary: Harmonic problem that this text exists to the course of running of the frequency converter, supporting and matching the problem and problem of generating heat, have analyzed one by one, and put forward the solution corresponded to.

Keyword: Frequency converter Harmonic wave Load Generate heat

Abstract: This paper analyzed the problem of harmonic wave, matching of load and
calorification for inverters in running, and made the relatively the measure.

Keywords: inverter harmonic wave loading calorification

A preface
Since the common frequency converter in the eighties entered the Chinese market, got very extensive employing during short more than ten years. At present, common frequency converter favor by the people more and more with intelligent, digitization, advantage such as being networked their. With the enlargement of the range of application of common frequency converter, questions exposed are more and more too, mainly have the following aspects:
Harmonic question
The frequency converter supports and matches the question
Question of generating heat
The above questions have already caused the attention about administrative department and factories and mines and made the relevant technical standard. Such as the harmonic question, China passed ” harmonic interim regulation on the management of the power system ” in 1984 and 1993 And GB/T-14549-93 standard, the harmonic wave that in order to restrain electric power system and power consuming apparatus from is polluted. To the above-mentioned problem, this text has analyzed and proposed solution and countermeasure.
2 harmonic questions and countermeasures
The main circuit form of the common frequency converter is generally made up of three parts: Commutate partly, go against and change partly and strain the wave part. Commutate some as the intersection of three-phase and bridge controlled rectifier, go against person who become part go against person who become for the intersection of IGBT and the intersection of three-phase and bridge type, and it is PWM wave form to export. As to the frequency converter of a pair of polar modulation, the wave form launching type of the voltage of its output is:
1
In the type: N- harmonic number of times n =1,3,5 ;
A1- switch angle, i =1,2,3 N/2;
Ed- frequency converter direct-flow side voltage;
N- year Bob.
By 1 The type can be seen, every harmonic amplitude is
2
Order n =1,The wave amplitude of base of the voltage of the output is to obtain the frequency converter:
3
From 1 , 2 , 3 The type can find out, really contain the other harmonic wave except base wave in the output voltage of the common frequency converter. It is lower harmonic wave once is usually of great impact to the electrical machinery load, cause the torque to pulse, and higher harmonic wave makes the frequency converter export leaking the electric current to increase of the cable again, make the electrical machinery exert oneself insufficiently, so the harmonic wave once of height that the frequency converter exports must be inhibited.
As noted previously, because the rectification of the common frequency converter adopts the diode not controlled bridge type partly and commutates the circuit, the middle strain the intersection of wave and part adopt large electric capacity as wave filter, so input of rectifier in practice charging electric current of the condenser in electric current, present the comparatively high and precipitous pulse wave, its harmonic weight is relatively large. In order to dispel the harmonic wave, can adopt the following countermeasures:
Increase frequency converter power impedance in the power
Generally, the inner impedance of the apparatus of the power can be played and buffered the function that the frequency converter direct current strains the wave capacitive inactive power. Impedance is short circuit impedance of the voltage transformer in this kind. As the power capacity is crossed for hour as to the frequency converter capacity, the impedance value is relative big, the less the harmonic content is; When the relative frequency converter of power capacity is the larger in capacity, impedance value is relative big, the larger the harmonic content is. As to the FR-F540 series frequency converter of Mitsubishi, when hindering in the power as 4%, can play a going to very good harmonic wave to inhibit role. Choose frequency converter supply power power transformer, had better choose, short out loud voltage transformer of impedance.
Install the reactor
Install reactor, increase frequency converter, power inner impedance of the power from outside in fact. Install and exchange the reactor on the exchange side of the frequency converter or in the direct-flow side installation direct current resisting device of the frequency converter, or installation, inhibit the harmonic electric current at the same time. The table has listed the content parallel table that Mitsubishi FR-A540 frequency converter installs the reactor and does not install the reactor.
The voltage transformer runs heterogeneously
The rectification of the common frequency converter is six pulse wave rectifiers partly, so the harmonic wave produced is relatively big. If employ the heterogeneous operation of the voltage transformer, make the angle of phase place mutually lack of 30 degrees like Y- – Two voltage transformers made up form the result equivalent to 12 pulse waves and can reduce harmonic electric current once 28% low, have played very good harmonic inhibitory activity.
Regulate year of the frequency converter Bob
From 1 , 2 , 3 Type can find out so long as Bob enough large year, low times of harmonic wave can be inhibited effectively, especially it is less than 1 o’clock to consult the wave amplitude and amplitude of signal carrier, the odd number harmonic wave under 13 times no longer appears.
Specialized wave filter
This specialized wave filter is used for measuring amplitude and phase place of the harmonic electric current of the frequency converter, and produced a just opposite electric current of phase place the same as the harmonic electric current amplitude, lead to the frequency converter, thus can absorb the harmonic electric current very effectively.
3 supports and matches question and countermeasure
It is various in style to produce machinery, performance and technological requirement are different, its torque characteristic is complicated, divided into three kinds of types on the whole: Support by permanent torque, air blower pump load and permanent power supported. To different load types, should choose different kinds of frequency converters.
The permanent torque is supported
It means that supports the torque to have nothing to do with the rotational speed that the permanent torque is supported, under any rotational speed, the torque keeps invariable. The permanent torque can divide into the rubing load and location to support again the type is supported.
About 150% that the starting torque of rubing load generally requires the specified torque, the torque generally requires about 100% of the specified torque to apply the brake, so the frequency converter should choose those to have invariable torque characteristic, start and apply the brake torque relatively loud, the frequency converter with chronic overload and with big overload capacity. Such as the frequency converter series FR-A540 of Mitsubishi.
Location can type support require loud starting torque and energy repay the function generally, can realize positive and negative to rotate fast, frequency converter should choose, have four quadrant run frequency converter of ability. Such as the frequency converter series FR-A241 of Mitsubishi.
Air blower pump load
The air blower pump load is that industry employs most apparatuses live at present, though the characteristics of pump and air blower are varied, rely mainly on the fact that centrifugal pump and centrifugal air blower are employed, common the intersection of frequency converter and at most application on the load. Air blower pump load whether one the intersection of square and torque support, the intersection of rotational speed and n and flow Q its, the torque T and power N of axle of the pump have the following relational expressions:
4
This kind of load is expected much to the performance of the frequency converter, only require economy and dependability, so choose to have U/f =Const controls the frequency converter of the mode. Such as Mitsubishi frequency converter FR-F540 L Series. The air blower is supported in the course of running actually, because of rotating the inertia bigger, so time is a very important problem the acceleration time and moderating of the frequency converter, can calculate according to the following formulae:
5
6
In the type: TACC- accelerates time s ;
TDEC- time of moderating s ;
Turning inertia N m2 that GD2- converts on the axle of the electrical machinery ;
G- acceleration of gravity, g =9.81m/s2 ;
Electromagnetic torque N.m of TM- motor ;
TL- supports the torque N.m ;
Initial speed r/min when nAS- system accelerates ;
Lapse speed r/min when nAE- system accelerates ;
Initial speed r/min when nDS- system moderates ;
Lapse speed r/min when nDE- system moderates .
Can find out from the having type, it is very important that the system that the air blower supports rotates the inertia and calculates. When the frequency converter is designed specifically, according to the having result of calculation, revise appropriately, in a situation that the frequency converter has not flowed and tripped and the voltage does not take place to trip while moderating in the frequency converter when started, choose the shortest time.
Pump load, in run in the course actually, easy to happen, breathe heavily, shake, suppress, pigeonhole with ink hanging down the effect, so frequency converter, when the person who select, want, choose, suitable for pump frequency converter of load and frequency converter want, go on, set for alone to the above-mentioned problem when the function is presumed:
Breathe heavily and shake: The frequency that breathes heavily to shake incident of measurement is clicked, through presuming some of jump frequency and width, avoid that the resonance phenomenon takes place systematically.
Suppress and press: While running at a low speed, because it causes the flow as zero to suppress and press systematically in pump load, thus cause the pump to burn out. When the frequency converter function is presumed, through limiting the lowest frequency of the frequency converter, and limited the lowest rotational speed of system of the critical point of the pump flow, this avoids emergence of this kind of phenomenon.

[Summary ] starts systematic characteristic and operation characteristic to analyze 600MW supercritical direct-flow boiler, and transferred to operation and attentive matters of direct current and paid explaining in detail to the aircrew in the start-up course, has also explained the control strategy in the whole start-up course emphatically, for competitor’s reference.

[Keyword ] is supercritical; Start the system; Operation characteristic

0 foreword

At present, 600MW aircrew becomes the pillar of every big electric wire netting gradually, practice has proved, the supercritical direct-flow aircrew has unparalleled superiority in such aspects as energy-conserving environmental protection, with the country ” Energy-conserving emission reduction ” , ” it is small to have greatly and press ” Wait for the issue of measure of a series of macro adjustments and controls, China will have large quantities of supercritical direct-flow aircrews to put into operation. This text makes an introduction to operation control and attentive matters that the direct-flow boiler is starting stage.

Systematic and brief introduction of 1

1. A characteristic and function of starting the systematic structure

The first stage of the project 2x600MW aircrew of Fei County of National Electricity Co., the boiler runs to originally grow Benson for supercritical varying voltage Direct-flow boiler, the type is HG one 1913/ 25. 4 one YM3. Start the system and take the recycling pump system for being built-in, is stored water tank, stove water circulation pump and accessory system to make up by soda separator, separator. The accessory system of the water circulation pump of the stove includes: It is in charge of the system, pass cold water system, recycling pipeline of minimum flow, cooling water system, stove water pump to wash the system including high pressure and low-voltage water develop the system that warm When.

When the boiler load is smaller than 35% BMCR, ‘ the separator plays the soda and separates function, the steam isolated has entered the heat exchanger system, water is entered and stored the water tank through the union pipe, according to store water level in the water tank, stand to province before the coal device in the watersupply pipeline or stand to dredge ink, expand in the the containers from the intersection of recycling and pump by the intersection of overflow and tube. The boiler load is when above 35% BMCR, the separator presents and does the attitude to run, is only regarded as the circulation component of the steam. Divided from storing the overflow tube drawn in water tank underpart into No. 2, No. 1 washes the pipeline, another overflow pipelines of No. 1, No. 2 and dredge water to expand the container and meet. Until the intersection of stove and water pump suck people, set up, come from, supply water, supply water drive platform, whom pipeline draw cross the pipeline of cold water at the tube, when circulating the pump and running, use self-sufficiency for water pipeline watersupply with store nearly the intersection of saturation and ink in the the water tanks, mix, avoid that the vapour takes place and lose to circulate the pump population. Draw pipeline of a minimum flow to pick up on the pipeline of recycling to store the water tank bottom, used for guaranteeing to circulate the pump and operate the necessary minimum flow.

1. 2 control sectors which store the water level of the water tank

Store the water level zero point of water tank to generally select in the minimum. 2 beginning with minimum upwardly. 35m sector, in order to protect circulating the minimum water level of the pump, the water level is lower than the water circulation pump of this stove to protect and trip. 2. 35- 6. 4m circulates the control sectors of pipeline regulating valves of recycling that the pump is exported. 6. 4- 6. 7m is a free sector. 6. 7- 7. 75m controls the sector for the overflow valve. 7. 75- 9m is a spare sector.

Download the full text 600MW supercritical direct-flow boiler and start the systematic operation characteristic discussion.pdf

The article has introduced the basic types of the important position in the power system of urban electric wire netting 10kV distribution system and systematic relay protection of urban electric wire netting 10kV distribution, have recommended several kinds of commonly used electric current of China at present to protect emphatically: Electric current protect, make time limit the intersection of electric current and protection, the intersection of electric current and speed disconnected to protect against time limit, and analyzed basic composition, protection domain, movement principle, fit method, pluses and minuses of all kinds of protectors, provide detailed exactly fixing the computational process.

Relay protection; It is calculated definitely that whole

The urban electric wire netting 10kV distribution system is an important component of five links such as generating electricity, switchyard, transmitting electricity, distribution and using electricity of power system. Whether it could run safely, steadily, reliably, not only concern directly the life of Party and government offices, industrial and mining enterprises, resident uses the noncongestion of the electricity, and involve the operation that the power system could be normal.

Important position in the power system of a electric wire netting 10kV distribution system

Because its region that is covered is extremely vast, extremely complicated influence of different human factors of running environment of the urban electric wire netting 10kV distribution system, the emergence of the electric trouble can’t be totally avoided. The accident happens in any in the power system, all probably exert a great influence on the operation of the power system. For example, when the short circuit accident happens in the apparatuses of some industrial and mining enterprises that in the system, thermal effects and electric power effects of the electric current because of shorting out, the fatal damage that often causes the electric equipment or electricity circuit may get to make the stable operation of the system destroyed seriously. In order to guarantee the normal running of the urban electric wire netting 10kV distribution system, must set up and continue the electric protector correctly.

Basic type of systematic relay protection of second, urban electric wire netting 10kV distribution

It is through narrowing accident range or predicting emergence of the accident to install the main function of continuing the electric protector in the urban electric wire netting 10kV system, to reach the dependability that the improvement system run, and the security and incessant that guarantees to supply power to the maximum extent.

Can imagine, utilize the fuse box not to meet the demands while finishing the above-mentioned task in 10kV system. Because Ann of the fuse box does not have very complete characteristic second, go out the high-pressure circuit the ability of the strong electric arc is insufficients, it is even possible to make a trouble further expand; What also lengthened and lost electrical power lasted at the same time. It is a perfect measure to only adopt and continue the electric protector. So, continuing the electric protector in 10kV system becomes the indispensable important component of running that the electric power system could be safe and reliable.

The difference of every physical quantities can form all kinds of principles and types and continue the electric protector when by normal running and trouble in the power system. The electric current reflecting the electric current changes protect such as applying the most extensive one in urban electric wire netting 10kV distribution system: Have time limit electric current protect and the intersection of electric current and protection, the intersection of electric current and speed broken to protect, cross, load, protect with a preface electric current protecting etc. against time limit definitely, reflect the change of the electric current as well as reflect the direction of the angle change of phase place between the voltage and electric current crosses the electric current to protect; Utilize the intersection of trouble and the intersection of earth connection and the intersection of electric capacity and electric current of way greater than it is the intersection of trouble and the intersection of earth connection and electric current of electric capacity of Luis that choose the earth connection way, generally act on and signal, mix the network system to adopt and click the operation way grounded in some developed cities neutrally directly because of the electric current bigger 10kV of electric capacity, a preface electric current protects and acts on and trips directly at this moment.

Analysis that three, several kinds of daily electric current protect

1 The electric current is protected against the time limit

The size of the electric current is relevant the movement time and shorting out for relay protection, short out in the the bigger electric current, the shorter the time of movement is; Short out in the the smaller electric current, the longer the time of movement is, this kind of protection is named against the time limit the electric current is protected. Although outside wiring is simple that the electric current is protected against the time limit, but the internal structure is very complicated, it is more difficult to debug; Do not continue the electric protector as what the electromagnetic type relay form far too in such aspects as accuracy, quick-acting of sensitivity and movement. This kind of protected mode is mainly applied to entering the line switch to protect of general user’s end at present, do not recommend using it at transformer substation 10kV switch qualified for the next round of competitions.

2 Make the time limit electric current to protect

1. Make the time limit electric current to protect. The size of the electric current with shorting out of movement time for relay protection has nothing to do, time is invariable, time relay whole to come on, obtain definitely by time. The time relay is adjustable continuously within the specific limits, this kind of protected mode is called making the time limit electric current to protect.

2. Composition of the relay. It is by the electromagnetic type time relay the component as the time limit to fix the time limit in the electric current to protect , electromagnetic type middle relay as exporting the component , electromagnetic type electric current relay as starting the component , electromagnetic type signal relay as the component of the signal Form. It generally adopts direct current to be operated, must set up direct current to reject. Make the time limit electric current to protect simply and reliably and totally depending on choosing the time of movement to obtain the alternative, have, the intersection of alternative and the intersection of cooperation and relatively easy, time limit of subordinate the relay is exactly made according to parameter calculated, obtained by time, alternative of movement can assurance, sensitivity of movement can meet the demands, not whole to debug more accurately and conveniently definitely. It is protected as 10kV electric current of switch qualified for the next round of competitions that this kind of protected mode is generally applied to the power system and turned into the distribution.

3. Make the basic principle that the electric current protects of the time limit. Order, ground in the system while being neutral in 10kV, the intersection of two phase and two relay that adopt extensively make the time limit electric current to protect. It is formed by the mutual inductor of two pieces of electric current and two pieces of electric current relay, relay and a signal relay in one time. The movement time of the protector is only decided by time, and with having nothing to do the size of electric current of short circuit of protecting the return circuit, so this kind of electric current is protected and called making the time limit electric current to protect.

4. It is calculated definitely that electric current of movement is whole. Cross and flow electric current relay movement electric current in the protector and exactly make the principle, protected in the peak load electric current that may appear in the circuit according to hiding to consider. That is to say, just start at not protecting into the circuit trouble only, but should not act when the electric current of peak load appear. For this reason must meet two following conditions:

1In normal cases, when present the electric current of peak load namely start and self-starting electric current of the motor, and electric current of spike,etc. uprushing and appearing in the circuit of user’s load Should not act. Namely:

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