CN206874493U - A kind of auxiliary power system for two-shipper backheat - Google Patents

Abstract

It the utility model is related to field of thermal power, specially a kind of auxiliary power system for two-shipper backheat.A kind of auxiliary power system for two-shipper backheat, including small turbine, synchronous automatic clutch, feed pump, gear box A, AC excitation dynamotor, gear box B, permanent-magnet speed governor and exciter alternator, the said equipment passes sequentially through shaft coupling connection, AC excitation dynamotor stator side accesses high-voltage Auxiliary electric system, and it is provided with synchronous device, AC excitation loop is provided between AC excitation dynamotor and exciter alternator, adjustable resistance is provided with AC excitation loop, exciter alternator possesses its DC excitation system.The rotating speed control of feed pump, is controlled by the excitation frequency of motor in the system, and unrelated with the power of motor, rotating speed and power realize uneoupled control, are greatly lowered the difficulty that operation controls.

Description

A kind of auxiliary power system for two-shipper backheat

Technical field

Field of thermal power is the utility model is related to, is specially that one kind is used to surpass（It is super）Criticality benchmark EC-BEST ( Echelon Cycle-Backpressure Extraction Steam Turbine) two-shipper heat regenerative system rotating speed-power The small turbine of uneoupled control-motor variable speed dual drive system, the unit of traditional heat regenerative system is also applied for, is especially suitable for pot The driving of stove feed pump, it is equally applicable to the driving of the variable speeds such as centrifugal fan, Silence Process axial fan, variable parameter operation The driving of equipment, the load -response-speed of unit efficiency and two-shipper backheat unit can be improved.

Background technology

Due to the increasingly raising of energy-saving and emission-reduction requirement, fired power generating unit develops to higher efficiency direction, and improving steam parameter is The important means of fired power generating unit generating efficiency is improved, the extra-supercritical unit reheat steam temperature that the country has put into operation at present has reached 620 DEG C, and develop to more high parameter, the continuous improvement of the steam turbine regenerative steam degree of superheat is brought therewith, and heat exchange entropy, which increases, constantly to be increased Big situation, especially intermediate pressure cylinder first paragraph situation of drawing gas are the most serious, influence unit efficiency and are further lifted.To solve this Problem, further improves unit efficiency, and recent year develops extra-supercritical unit EC-BEST two-shipper heat regenerative systems（Referred to as " two-shipper heat regenerative system "）, similar system is actually external more application in the sixties in last century, but later due to solidifying Vapour formula small turbine（Referred to as " the small machine of pure condensate "）Development, water supply pump driving BEST small turbines（Back pressure-backheat of drawing gas Small turbine, referred to as " the small machines of BEST "）Gradually substituted by the small machine of pure condensate, and two-shipper heat regenerative system unit Changing load-acceleration is slow, it is double Machine heat regenerative system is gradually backed out the arena of history.Have benefited from the raising of the through-flow design level of the small machines of BEST at present, under equal conditions, Traditional heat regenerative system using the small machine of pure condensate is less than using the therrmodynamic system heat consumption of the small machines of BEST, therefore, in recent years, two-shipper returns Hot systems cause extensive concern, but due to the tape splicing main steam turbine that draws gas of the small machines of BEST（Abbreviation main frame）High-pressure heater（Letter Claim " height adds "）, when unit varying duty or unusual service condition feedwater flow fluctuate widely, the water level that height adds is difficult to control, at present still The control problem for confirming to have solved the small machines of BEST without the case that engineering puts into operation.

In addition, with the increase of power network peak-valley difference, and a large amount of new energy access power networks, thermal power plant increasingly undertakes numerous The peak regulation and frequency modulation task of weight, cause subsidiary engine more time off-design operating mode to be run, and frequent fluctuation, and efficiency reduces, especially It is that the energy consumption level of the large-scale subsidiary engine such as feed pump, blower fan has a great influence to the efficiency of unit, it is also desirable to have new type of drive to carry High subsidiary engine drive efficiency.

The content of the invention

The utility model provides a kind of auxiliary power system for two-shipper backheat, it is possible to achieve whole shafting turns in change Under fast service condition, adjusted by motor（Power-loaded self-adaptive）The rotating speed of driven equipment, and small turbine（Include BEST Small machine and the small machine of pure condensate, referred to as " small machine "）It can be run under admission valve standard-sized sheet mode, without regulation, make entering for small machine Vapour, draw gas（The small machines of BEST）, exhaust steam flow keep stable.Due to the small machines of BEST draw gas be discharged into it is high plus, its steam flow it is steady It is fixed, two-shipper heat regenerative system can be made in unit variable load operation, will not Yin Gaojia problem of water level control, and have influence on unit change Load rate；Due to small machine valve wide open, small machine is able to always work in close to design conditions, can also make unit（Including passing System backheat unit and two-shipper backheat unit）In the range of full load, subsidiary engine drive efficiency is set to be held in higher level；Adjusted Amount, it is to be controlled by the excitation frequency of motor, with motor such as the rotating speed control of the control of boiler feedwater flow, i.e. feed pump Power it is unrelated, rotating speed and power realize uneoupled control, make operation control difficulty be greatly lowered.

The utility model adopts the following technical scheme that realization：A kind of auxiliary power system for two-shipper backheat, bag Include small machine, synchronous automatic clutch（Abbreviation clutch）, feed pump, gear box A, AC excitation dynamotor（Referred to as main electricity Machine）, gear box B, permanent-magnet speed governor and exciter alternator（Abbreviation exciter）, the said equipment passes sequentially through shaft coupling connection, main Motor stator side joint enters high-voltage Auxiliary electric system, and is provided with synchronous device, is returned between main motor and exciter provided with AC excitation Road, adjustable resistance is provided with AC excitation loop, and exciter possesses its DC excitation system.

Operation principle：In unit normal operation, by adjusting permanent-magnet speed governor, to adjust the rotating speed of exciter, so as to change Become the frequency of exciter output alternating current, the rotor field frequency of main motor thus change, because the stator of main motor returns Power frequency station service electrical system is accessed on road, and the rotary speed of rotor is exactly the speed discrepancy of stator rotating excitation field and rotor rotating excitation field, because This, the purpose of control shafting transfer rotor speed has been finally reached by controlling permanent-magnet speed governor.In shafting driving equipment and by The shaft power equilibrium relation of driving equipment is such：The shaft power of feed pump has with its rotating speed and supply line drag characteristic Close, small shaft power and steam parameter before its admission valve aperture and valve（Temperature, pressure）It is relevant, and steam parameter and main frame Load it is relevant, the shaft power of main motor is relevant with the load that it undertakes, and at any one time, the power of all devices in shafting Poised state is necessarily in, the difference of small machine and feed pump shaft power is undertaken by main motor, as long as this shaft power difference does not surpass Go out main motor name plate rating, shafting can safe and stable operation, the rotating speed control of the rotating speed of shafting, i.e. feed pump is and power What control did not associated, that is, uneoupled control is realized, the regulation quality of the DC excitation system of exciter can will meet to lead in real time The excitation of motor needs, and ensures main motor without departing from static stability limit.

The utility model can also adopt the following technical scheme that realization：A kind of subsidiary engine dynamical system for two-shipper backheat System, including small machine, clutch, feed pump, gear box A, main motor, the said equipment pass sequentially through shaft coupling connection, and main motor is fixed Sub- side joint enters high-voltage Auxiliary electric system, and is provided with synchronous device, in addition to exciter, exciter motor（Referred to as " excitation electricity Machine "）And frequency converter, exciter are connected with excitation electromotor by shaft coupling, exciter possesses its DC excitation system, main motor with AC excitation loop is provided between exciter, the power supply of frequency converter is derived from low pressure station service electrical system, transducer drive excitation electromotor.

Operation principle：By frequency converter, to adjust the rotating speed of excitation electromotor, so as to change the frequency of exciter output alternating current Rate, the rotor field frequency of main motor thus change, and because power frequency station service electrical system is accessed in the stator loop of main motor, turn The rotary speed of son is exactly the speed discrepancy of stator rotating excitation field and rotor rotating excitation field, therefore, by controlling frequency converter and final The purpose of control shafting transfer rotor speed is reached.Driving equipment and the shaft power equilibrium relation of driven equipment are these in shafting Sample：The shaft power of feed pump is relevant with its rotating speed and supply line drag characteristic, small shaft power and its admission valve aperture It is relevant with steam parameter before valve, and steam parameter is relevant with the load of main frame, the load that the shaft power of main motor undertakes with it It is relevant, and at any one time, the power of all devices is necessarily in poised state, the difference of small machine and feed pump shaft power in shafting Volume is undertaken by main motor, if this shaft power difference without departing from main motor name plate rating, shafting can safe and stable operation, The rotating speed control of the rotating speed of shafting, i.e. feed pump does not associate with Power Control, that is, realizes uneoupled control, exciter it is straight The regulation quality of stream excitation system can will in real time meet the excitation needs of main motor, ensure main motor without departing from static-stability pole Limit.

The utility model can also adopt the following technical scheme that realization：A kind of subsidiary engine dynamical system for two-shipper backheat System, including small machine, clutch, feed pump, gear box A and main motor, the said equipment passes sequentially through shaft coupling connection, in addition to becomes Frequency device and transformer, main motor stator side joint enters high-voltage Auxiliary electric system, and is provided with synchronous device, and the AC excitation of main motor takes From high-voltage Auxiliary electric system, excitation is provided it by frequency converter and transformer.

Operation principle：By frequency converter, to adjust the exciting current frequency of main motor rotor loop, the rotor magnetic of main motor Field frequencies range thus changes, and because power frequency station service electrical system is accessed in the stator loop of main motor, the rotary speed of rotor is exactly The speed discrepancy of stator rotating excitation field and rotor rotating excitation field, therefore, it has been finally reached by controlling frequency converter in control shafting The purpose of rotor speed, the effect of transformer is matching frequency converter output voltage, electric current and main motor rotor loop demand excitation Voltage, electric current.Driving equipment and the shaft power equilibrium relation of driven equipment are such in shafting：The shaft power of feed pump with Its rotating speed is relevant with supply line drag characteristic, and small shaft power is relevant with steam parameter before its admission valve aperture and valve, And steam parameter is relevant with the load of main frame, the shaft power of main motor is relevant with the load that it undertakes, and at any one time, shafting The power of middle all devices is necessarily in poised state, and the difference of small machine and feed pump shaft power is undertaken by main motor, as long as this Individual shaft power difference is without departing from main motor name plate rating, shafting can safe and stable operation, the rotating speed of shafting, i.e. feed pump Rotating speed control does not associate with Power Control, that is, realizes uneoupled control, the regulation quality of the AC excitation system of main motor Its excitation needs can be met in real time, ensure main motor without departing from static stability limit.

The utility model can also adopt the following technical scheme that realization：A kind of subsidiary engine dynamical system for two-shipper backheat System, including the small machine of feed pump, BEST, the speed change clutch with blocking function（Equivalent to gear-box+synchronization with blocking function certainly Dynamic clutch, referred to as " speed change clutch "）And main motor, the said equipment pass sequentially through shaft coupling connection, main motor stator side joint Enter high-voltage Auxiliary electric system, and be provided with synchronous device, the steam discharge of the small machines of BEST accesses oxygen-eliminating device by valve A and valve B respectively And condenser（Or steam exhaust device）, in addition to exciter, excitation electromotor and frequency converter, exciter and excitation electromotor pass through shaft coupling Connection, exciter possess its DC excitation system, AC excitation loop, the power supply of frequency converter are provided between main motor and exciter It is derived from low pressure station service electrical system, transducer drive excitation electromotor.

The utility model can still adopt the following technical scheme that realization：A kind of subsidiary engine dynamical system for two-shipper backheat System, including feed pump, the small machine of pure condensate, speed change clutch and main motor, the said equipment pass sequentially through shaft coupling connection, and main motor is fixed Sub- side joint enters high-voltage Auxiliary electric system, and is provided with synchronous device, and the steam discharge of the small machine of pure condensate accesses condenser by valve B（Or row Vapour device）, cooling steam accesses the small machine cylinder body of pure condensate by valve C, in addition to exciter, exciter motor and frequency converter are encouraged Magnetomechanical is connected with excitation electromotor by shaft coupling, and exciter possesses its DC excitation system, is provided between main motor and exciter AC excitation loop, the power supply of frequency converter are derived from low pressure station service electrical system, transducer drive excitation electromotor.

Above-mentioned 2 technical scheme operation principles are identical with preceding 3 technical schemes, and difference is, feed pump is located at axle One end of system, feed pump use the technical scheme when can not use Double shaft-extension design, and the mode that main motor first starts, small machine can not Deviate from from shafting, can only be rotated with whole shafting.

The beneficial effects of the utility model are：

1）The subsidiary engine driving of prior art typically uses single power, and driving equipment will have certain allowance, be given with thermal power plant Exemplified by water pump, the feed pump design of direct current cooker will meet unit 105%BMCR（Drum boiler is 110%BMCR）The demand of operating mode, And drive the small machine of feed pump also to have certain allowance relative to feed pump, and during unit oepration at full load, feed pump shaft power About 80% or so of design conditions, unit is in 50% load operation, and the 20% of feed pump shaft underpower design conditions, and it is small Machine will also keep the shaft power adaptable with this, substantial deviation design conditions, efficiency be influenceed very big.According to of the present utility model Technical scheme, small machine can keep valve wide open to run, and in the range of unit full load, consistently remain close to design conditions fortune OK, higher operational efficiency is kept, the regulation of speed of feedwater is completed by the adjustment of field excitation of electrical system.

2）The feed-water pump of prior art, generally require setting and start pump or start stand-by pump, and it is of the present utility model Technical scheme, which need not be set, to be started pump or opens standby pump, during unit starting, is run by main motor with motor working condition, driving feedwater Pump, unit starting process is completed, now, clutch is in disengaged condition, small machine is cut off from shafting, feed pump is individually by leading Motor drives（Now, gear box A is in speedup mode of operation）.When unit reaches certain load, using the teaching of the invention it is possible to provide enough vapour sources when Wait, small machine puts into operation, clutch engagement, drives feed pump, with the change of main unit load, when small shaft power is more than feedwater Needed for pump during shaft power, main motor is in generating state（Now, gear box A is in decelerating operation pattern）, conversely, being in electronic shape State.

3）The utility model is particularly suitable for use in the use of two-shipper heat regenerative system, BEST small machines, due to tape splicing main frame it is high plus, In prior art, feed pump is operated alone in small machine, and working conditions change is more violent, and height plus water level are difficult to control, thus, main frame Load change, i.e. peak modulation capacity are weakened, and the technical solution of the utility model, small machine need not be adjusted（Admission valve is complete Open）, therefore, the peak modulation capacity of unit is not interfered with not only, and can also improve unit efficiency.

Brief description of the drawings

Fig. 1 is small turbine-motor variable speed dual drive feed-water pump schematic diagram of exciter Driven by Coaxial.

Fig. 2 is small turbine-motor variable speed dual drive feed-water pump signal that exciter is driven by excitation electromotor Figure.

Fig. 3 is small turbine-motor variable speed dual drive feed-water pump signal that excitation is provided by station service frequency conversion Figure.

Fig. 4 is the small machines of BEST-motor variable speed dual drive feed-water pump that exciter is driven by excitation electromotor（Feed pump Positioned at shafting one end）Schematic diagram.

Fig. 5 is the small machine of pure condensate-motor variable speed dual drive feed-water pump that exciter is driven by excitation electromotor（Feed pump Positioned at shafting one end）Schematic diagram.

In figure：1- small turbines, 2- synchronization automatic clutches, 3- feed pumps, 4- gear box As, the electronic hair of 5- AC excitations Motor, 6- gear box Bs, 7- permanent-magnet speed governors, 8- exciter alternators, 9- exciter motors, 10- frequency converters, 11- transformations Device, the small machines of 12-BEST, 13- speed change clutch, the small machine of 14- pure condensates, 15- synchronous devices.

Embodiment

Embodiment 1：As shown in figure 1, being designed using the utility model, design parameter can be flexible according to requirement of engineering Selection, if demand feed pump design speed scope is 3000~6000rpm（Corresponding AC excitation frequency range is 40~30hz, Corresponding permanent-magnet speed governor output speed scope is 89.3%~33.5%）, the fast ratio of gear box A can be used as 5, main motor rotating speed model Enclose for 600~1200rpm, main motor magnetic pole logarithm is 1, exciter magnetic pole logarithm is 2, gear box B speed is than being 2.293 to set Meter, also can be according to the technical conditions such as the critical speed of main motor and carbon brush slip-ring, preferably other specification.

Small turbine-motor variable speed dual drive feed-water pump of Fig. 1 signals rotating speed-power decoupled control（Exciter Driven by Coaxial）.

During feedwater pump startup, small machine can be selected first to start, or the mode that main motor first starts.

When small machine first starts, small machine red switch, clutch engages, and all devices turn in drive feed pump, main motor and shafting It is dynamic, to 2800rpm（Typically under the rotating speed, small machine starts and terminated, and small machine switchs to unit DCS by MEH controls and controlled）, keep turning Speed is stable to carry out electric operation, now motor speed 560rpm, permanent-magnet speed governor input rotating speed 1284rpm, and regulation permanent magnetism is adjusted Fast device output speed is to 1220rpm（About output speed 95%）, exciter, which opens, encourages, and now, exciter output AC excitation frequency is about 40.67hz, plus main motor rotor mechanical separator speed, the electricity that frequency is 50hz can be thus induced in main motor stator loop Pressure, after examining the same period by synchronous device, switch is closed a floodgate, and stator loop is connected, and main motor is directly accessed high-voltage Auxiliary electric system.Treat Small machine is controlled by MEH, after switching to unit DCS controls.Rotating speed control enters steam control valve control by small machine, is changed into electric loop Frequency Converter Control, continue raising speed, the speed of feedwater section into unit to water management（Generally 3000~6000rpm）, With the increase of feed pump capacity, small machine progressively can be entered into steam control valve progressively to standard-sized sheet, reach maximum energy-saving state.

When main motor first starts, throw-out-of clutch, small machine rotor is remained static, and feed pump liter is driven by main motor Speed.Adjustable resistance in main motor rotor AC excitation loop is adjusted to the larger state of resistance, the rotor windings loop of main motor By adjustable resistance, carbon brush and slip ring, a closed-loop path is formed with the stator loop of exciter, equivalent to Wound-rotor asynchronous electricity Machine, switch are closed a floodgate, and stator loop is connected, and main motor is directly accessed high-voltage Auxiliary electric system, adjust adjustable resistance, control main motor Rotating speed is maintained at about 560rpm（Also other rotating speeds may be selected）, the exciting current about 40.67hz of now rotor loop sensing, permanent magnetism Speed regulator input rotating speed 1284rpm, regulation permanent-magnet speed governor output speed 1220rpm（About output speed 95%）, exciter Qi Li, exciter also produce the AC excitation electric current of identical frequency, are stepped up the direct current magnetic force electric current of exciter, make main motor AC excitation be transitioned into and provided by exciter by speed discrepancy sensing, while progressively regulation reduces the resistance of adjustable resistance, until Excision, the control of main motor rotating speed is set to switch to permanent-magnet speed governor control by adjustable resistance control.Progressively reduce permanent-magnet speed governor output Rotating speed, main motor continue raising speed, the speed of feedwater section into unit to water management（Generally 3000~6000rpm）, it is small After equipment is for red switch condition, red switch, raising speed, until clutch engages, and it is synchronous with speed of feedwater holding, afterwards, continue out big Small machine enters steam control valve, until standard-sized sheet.

Embodiment 2：As shown in Fig. 2 being designed using the utility model, design parameter can be flexible according to requirement of engineering Selection, if demand feed pump design speed scope is 3000~6000rpm（Corresponding AC excitation frequency range is 40~30hz, Corresponding frequency converter adjustable range is 40.4~30.3hz, and excitation electromotor uses asynchronous machine, and its revolutional slip is according to 1% measuring and calculating）, can Using use gear box A speed than for 5, the main motor range of speeds as 600~1200rpm, main motor magnetic pole logarithm be 1, exciter magnetic Number of pole-pairs is 2, excitation electromotor magnetic pole logarithm is 2, also can be excellent according to technical conditions such as the critical speed of main motor and carbon brush slip-rings Select other specification.

In the present embodiment, the permanent-magnet speed governor or fluid-flywheel clutch that are set between exciter and excitation electromotor Deng other speed control devices.

Small turbine-motor variable speed dual drive feed-water pump of Fig. 2 signals rotating speed-power decoupled control（Exciter Driven by excitation electromotor）.

During feedwater pump startup, small machine can be selected first to start, or the mode that main motor first starts.

When small machine first starts, small machine red switch, clutch engages, and all devices turn in drive feed pump, main motor and shafting It is dynamic, it can select in small machine rotating speed 2800rpm（Also other rotating speeds may be selected, but rotating speed will be stablized）Shi Jinhang electric operations, this When main motor rotating speed 560rpm, start excitation electromotor, regulation frequency converter output frequency be about 41.08hz, make exciter rotating speed protect To hold in 1220rpm, exciter, which opens, encourages, now, exciter output AC excitation frequency about 40.67hz, plus main motor rotor machine Tool rotating speed, the voltage that frequency is 50hz can be thus induced in main motor stator loop, it is fixed after examining the same period by synchronous device Sub-loop is connected, and main motor is directly accessed high-voltage Auxiliary electric system.Treat that small machine is controlled by MEH, after switching to unit DCS controls.It Afterwards, rotating speed control continues raising speed, into machine by the Frequency Converter Control entered steam control valve control, be changed into electric loop of small machine Speed of feedwater section of the group to water management（Generally 3000~6000rpm）, with the increase of feed pump capacity, can progressively by Small machine enters steam control valve progressively to standard-sized sheet, reaches maximum energy-saving state.

When main motor first starts, throw-out-of clutch, small machine rotor is remained static, and feed pump liter is driven by main motor Speed.Excitation electromotor is started by frequency converter, adjusts the output frequency of frequency converter in 50.5hz, excitation electromotor rotating speed about 1500rpm （Calculate according to revolutional slip 1%）, exciter, which opens, is encouraged, and the voltage that frequency is 50hz can be thus induced in main motor stator loop, After examining the same period by synchronous device, stator loop is connected, and main motor is directly accessed high-voltage Auxiliary electric system.Gradually reduce frequency converter Output frequency, main motor is since static and continues raising speed, the speed of feedwater section into unit to water management（Generally 3000~6000rpm）, after small equipment is for red switch condition, red switch, raising speed, until clutch engages, keep same with speed of feedwater Step, afterwards, continues out size machine and enters steam control valve, until standard-sized sheet.

In the present embodiment, permanent-magnet speed governor can be also set between exciter and excitation electromotor（Or fluid-flywheel clutch etc. its His speed control device）, exciter rotating speed is adjusted by permanent-magnet speed governor, and substitute the effect of frequency converter.

Embodiment 3：As shown in figure 3, being designed using the utility model, design parameter can be flexible according to requirement of engineering Selection, if demand feed pump design speed scope is 3000~6000rpm（Corresponding AC excitation frequency range is 40~30hz）, The fast ratio of gear box A can be used also may be used for the design that 5, range of motor speeds is 600~1200rpm, motor pole logarithm is 1 According to the technical conditions such as the critical speed of motor and carbon brush slip-ring, preferably other specification.

Small turbine-motor variable speed dual drive feed-water pump of Fig. 3 signals rotating speed-power decoupled control（Excitation by Station service frequency conversion provides）.

During feedwater pump startup, small machine can be selected first to start, or the mode that main motor first starts.

When small machine first starts, small machine red switch, clutch engages, and all devices turn in drive feed pump, main motor and shafting It is dynamic, it can select in small machine rotating speed 2800rpm（Also other rotating speeds may be selected, but rotating speed will be stablized）Shi Jinhang electric operations, this When main motor rotating speed 560rpm, put into AC excitation, regulation frequency converter output frequency be about 40.67hz, plus main motor rotor Mechanical separator speed, the voltage that frequency is 50hz can be thus induced in main motor stator loop, after examining the same period by synchronous device, Stator loop is connected, and main motor is directly accessed high-voltage Auxiliary electric system.Treat that small machine is controlled by MEH, after switching to unit DCS controls. Afterwards, rotating speed control is continued raising speed, entered by the Frequency Converter Control entered steam control valve control, be changed into electric loop of small machine Speed of feedwater section of the unit to water management（Generally 3000~6000rpm）, can be progressively with the increase of feed pump capacity Small machine is entered into steam control valve progressively to standard-sized sheet, reaches maximum energy-saving state.

When main motor first starts, throw-out-of clutch, small machine rotor is remained static, and feed pump liter is driven by main motor Speed.AC excitation is put into, regulation frequency converter output frequency is 50hz, and thus can induce frequency in main motor stator loop is 50hz voltage, after examining the same period by synchronous device, stator loop is connected, and main motor is directly accessed high-voltage Auxiliary electric system.By Step reduces frequency converter output frequency, and main motor is since static and continues raising speed, the speed of feedwater into unit to water management Section（Generally 3000~6000rpm）, after small equipment is for red switch condition, red switch, raising speed, until clutch engages, with feedwater Revolution speed keeps synchronous, afterwards, continues out size machine and enters steam control valve, until standard-sized sheet.

Gear box A or speed change clutch, clutch in above-described embodiment 1,2,3 are preferentially arranged on gear-box Speed end, clutch engagement and during locking is equivalent to gear box A, and during throw-out-of clutch, feedwater can be operated alone in small machine Pump, equivalent to existing technical scheme, unit operation can not be influenceed in the case of electrical malfunction.

Embodiment 4：As shown in figure 4, being designed using the utility model, design parameter can be flexible according to requirement of engineering Selection, if demand feed pump design speed scope is 3000~6000rpm（Corresponding AC excitation frequency range is 40~30hz）, Speed change clutch speed can be used than for 5, range of motor speeds is 600~1200rpm, motor pole logarithm is 1 design（It is main The excitation system of motor is identical with the technical scheme in embodiment 2）, also can be according to skills such as the critical speed of motor and carbon brush slip-rings Art condition, preferably other specification.

During feedwater pump startup, the small machines of BEST can be selected first to start, or the mode that main motor first starts.The small machines of BEST first open It is identical with embodiment 1,2,3 when dynamic.When main motor first starts, electrical system control and embodiment 1,2,3 also complete phase Together, difference is, main motor first starts, when driving feedwater pump operation, also simultaneously with the small machine synchronous rotaries of BEST, now Need the small machine admission valves of BEST and the valve Close All that draws gas, the valve A of steam discharge to oxygen-eliminating device are closed, the small machines of BEST send axle envelope Steam, the valve B of steam discharge to condenser are opened, and the small machines of BEST keep vacuumizing state, prevent rotor air blast from overheating.Main motor list Under only type of drive, general feed pump keeps appropriate fixed rotating speed, can select about 3000rpm or so or other suitable turn Speed, speed of feedwater will meet unit starting, until unit reaches certain load, main frame high pressure cylinder steam discharge parameter disclosure satisfy that The small machine red switch conditions of BEST.In the case where meeting feedwater demand pump, selection of speed is as low as possible, and is run using constant speed, uses Feed water by-pass adjusts valve regulation feedwater flow.After the small equipments of BEST are for red switch condition, the small machines of BEST enter steam control valve and progressively opened Open, start into vapour, undertake output, when condition meets, progressively close valve B, the opening small machine steam discharge of valve A, BEST, which is switched to, to be removed Oxygen device, before the small shaft powers of BEST exceed shaft power needed for feed pump, speed change clutch locking, prevent the small machines of BEST from entering vapour Regulating valve is progressively opened greatly, until during standard-sized sheet, after main motor shaft power is decreased to zero, speed change clutch disengages.Above-mentioned mistake Cheng Zhong, speed of feedwater are controlled by electric loop all the time.

Embodiment 5：As shown in figure 5, being designed using the utility model, design parameter can be flexible according to requirement of engineering Selection, if demand feed pump design speed scope is 3000~6000rpm（Corresponding AC excitation frequency range is 40~30hz）, Speed change clutch speed can be used than for 5, range of motor speeds is 600~1200rpm, motor pole logarithm is 1 design（It is main The excitation system of motor is identical with the technical scheme in embodiment 2）, also can be according to skills such as the critical speed of motor and carbon brush slip-rings Art condition, preferably other specification.

During feedwater pump startup, the small machine of pure condensate can be selected first to start, or the mode that main motor first starts.The small machine of pure condensate first opens It is identical with embodiment 1,2,3 when dynamic.When main motor first starts, electrical system control and embodiment 1,2,3 also complete phase Together, difference is, main motor first starts, when driving feedwater pump operation, also simultaneously with the small machine synchronous rotary of pure condensate, now The small machine admission valve Close All of pure condensate is needed, the small machine of pure condensate send gland steam, and the valve B of steam discharge to condenser is opened, pure condensate Small machine is kept vacuumizing state, and valve C is opened, and is sent into cooling steam, prevents rotor air blast from overheating（The small machine blades of BEST are shorter, Rim velocity is smaller, can be not provided with cooling steam system, the small several grade blades in machine end of pure condensate are longer, and rim velocity is larger）.Main motor It is operated alone under mode, general feed pump keeps appropriate fixed rotating speed, can select in about 3000rpm or so, speed of feedwater Meet unit starting, until unit load reaches to a certain degree, main frame high pressure cylinder steam discharge parameter disclosure satisfy that the small machine punching of pure condensate Turn condition, in the case where meeting feedwater demand pump, selection of speed is as low as possible, and is run using constant speed, feed water by-pass regulation Valve regulation feedwater flow.After the small equipment of pure condensate is for red switch condition, the small machine of pure condensate enters steam control valve and progressively opened, and starts into vapour, Output is undertaken, closes valve C, cuts off cooling steam, before the small shaft power of pure condensate exceedes shaft power needed for feed pump, speed change Clutch locking, prevent the small machine of pure condensate from entering steam control valve and progressively opening greatly, until during standard-sized sheet, main motor shaft power is decreased to After zero, speed change clutch disengages.In said process, speed of feedwater is controlled by electric loop all the time.

Excitation mode in embodiment 4,5 is in the same manner as in Example 2, can also be identical with embodiment 1,3.

Small machine described in the utility model（Include the small machines of BEST and the small machine of pure condensate）Can also be other kinds of power-equipment, Driven equipment can be the equipment of other variable speeds control such as feed pump or blower fan, be equally applicable to other industry The equipment of similar demand.

Claims (5)

1. a kind of auxiliary power system for two-shipper backheat, it is characterised in that including small turbine（1）, synchronous automatic clutch （2）, feed pump（3）, gear box A（4）, AC excitation dynamotor（5）, gear box B（6）, permanent-magnet speed governor（7）And synchronization Exciter（8）, the said equipment pass sequentially through shaft coupling connection, AC excitation dynamotor（5）Stator side accesses high-voltage Auxiliary Electric system, and it is provided with synchronous device（15）, AC excitation dynamotor（5）With exciter alternator（8）Between encouraged provided with exchange Magnetic loop, adjustable resistance, exciter alternator are provided with AC excitation loop（8）Possess its DC excitation system.

2. a kind of auxiliary power system for two-shipper backheat, it is characterised in that including small turbine（1）, synchronous automatic clutch （2）, feed pump（3）, gear box A（4）, AC excitation dynamotor（5）, the said equipment pass sequentially through shaft coupling connection, hand over Flow exciter motorgenerator（5）Stator side accesses high-voltage Auxiliary electric system, and is provided with synchronous device（15）, in addition to synchronous excitation Machine（8）, exciter motor（9）And frequency converter（10）, exciter alternator（8）With exciter motor（9）Pass through shaft coupling Device connects, exciter alternator（8）Possess its DC excitation system, AC excitation dynamotor（9）With exciter alternator（8）It Between be provided with AC excitation loop, frequency converter（10）Power supply be derived from low pressure station service electrical system, transducer drive exciter driving electricity Machine.

3. a kind of auxiliary power system for two-shipper backheat, it is characterised in that including small turbine（1）, synchronous automatic clutch （2）, feed pump（3）, gear box A（4）, AC excitation dynamotor（5）, the said equipment pass sequentially through shaft coupling connection, also Including frequency converter（10）And transformer（11）, AC excitation dynamotor（5）Stator side accesses high-voltage Auxiliary electric system, and sets There is synchronous device（15）, AC excitation dynamotor（5）AC excitation be derived from high-voltage Auxiliary electric system, pass through frequency converter （10）And transformer（11）Provide it excitation.

4. a kind of auxiliary power system for two-shipper backheat, it is characterised in that including feed pump（3）, the small machines of BEST（12）, band The speed change clutch of blocking function（13）With AC excitation dynamotor（5）, the said equipment pass sequentially through shaft coupling connection, hand over Flow exciter motorgenerator（5）Stator side accesses high-voltage Auxiliary electric system, and is provided with synchronous device（15）, the small machines of BEST（12）'s Steam discharge accesses oxygen-eliminating device and condenser or steam exhaust device, in addition to exciter alternator by valve A and valve B respectively（8）, excitation Machine motor（9）And frequency converter（10）, exciter alternator（8）With exciter motor（9）Connected by shaft coupling, it is synchronous Exciter（8）Possess its DC excitation system, AC excitation dynamotor（5）With exciter alternator（8）Between be provided with exchange Energized circuit, frequency converter（10）Power supply be derived from low pressure station service electrical system, frequency converter（10）Drive exciter motor（9）.

5. a kind of auxiliary power system for two-shipper backheat, it is characterised in that including feed pump（3）, the small machine of pure condensate（14）, band The speed change clutch of blocking function（13）With AC excitation dynamotor（5）, the said equipment pass sequentially through shaft coupling connection, hand over Flow exciter motorgenerator（5）Stator side accesses high-voltage Auxiliary electric system, and is provided with synchronous device（15）, the small machine of pure condensate（14）'s Steam discharge accesses condenser or steam exhaust device by valve B, and cooling steam accesses the small machine cylinder body of pure condensate by valve C, in addition to same Walk exciter（8）, exciter motor（9）And frequency converter（10）, exciter alternator（8）With exciter motor（9）It is logical Cross shaft coupling connection, exciter alternator（8）Possess its DC excitation system, AC excitation dynamotor（5）With synchronous excitation Machine（8）Between be provided with AC excitation loop, frequency converter（10）Power supply be derived from low pressure station service electrical system, frequency converter（10）Driving is encouraged Magnetomechanical motor（9）.