The stator of steam turbine generator full immersed type self circular loop of evaporative cooling
Technical field
The present invention relates to a kind of structure that does not fire the self-loopa evaporative cooling loop of liquid medium cooling steamer generator stator core, winding coil and fixed part thereof with high insulation low boiling.
Background technology
In the prior art, the stator core of turbo generator, winding coil and fixed part thereof, the type of cooling commonly used is gas (air, hydrogen) cooling and water cooling (abbreviation water-cooled), they respectively have its pros and cons.Gas all-pervasively disperses heat generating components to large tracts of land with it, and is more favourable as the cooling raio of iron core etc., but to concentrating heat generating components such as winding coil and end construction spare etc. then to form the local overheating district easily, thereby influence the safe operation of insulation life and motor.Water-cooled is then opposite with gas cooled, disperses heat generating components for large tracts of land, and water-cooled is arranged comparatively difficulty.Thereby large turbo-type generator, generally adopt water-hydrogen-hydrogen, or water-water-hydrogen, or water-water-sky mixes the type of cooling for three kinds.
Above-mentioned several type of cooling all is to utilize " specific heat " of flowing liquid or gas medium to take away the heat that loss produced of each parts.The common feature of these types of cooling is: because internal water cooling is all adopted in motor stator winding inside, iron core and heat generating components thereof all adopt air or hydrogen cooling, therefore have winding coil current density height, copper consumption is few, motor size is little, operating temperature is low and transships advantages such as nargin is big.Shortcoming is: water is the high medium of a kind of conductance, and hydrogen is a kind of gas medium of explosion hazard.Therefore, water in case from winding coil inside to external leakage, will destroy winding coil insulation or cause the major accident of phase fault.Hydrogen leaks more serious explosion accident can take place.More than this accident take place particularly frequent and serious in long water, the hydrogen-cooled unit in running time.And along with the continuous increase of generator single-machine capacity, more than several types of cooling do not satisfied the cooling requirement of big capacity unit.
Because water, hydrogen-cooled but medium are the hidden danger that causes major accident, and do not satisfy the cooling technology requirement that develops the super-huge turbogenerator group.So seek new coolant, study new cooling technology, the requirement of the reliability of the safe operation of raising motor becomes more and more urgent.A lot of at present countries all pay attention to the research and development of novel cooling technology.One of approach is that employing is not burnt, non-conductive, nontoxic liquid medium is replaced water, hydrogen-cooled but medium.As states such as Russia, Switzerland, Japan and Canada, will wait the liquid medium that employing does not fire on the level capacity generator to come cooling motor more than 300~500MW.
Aspect the novel cooling technology of large-size machine, the evaporation cooling technique of the autonomous research and development of China is taken the course of its own.So-called evaporative cooling is that cooling liquid is poured in the motor stator chamber, utilizes the principle of liquid medium gasification heat absorption to come cooling motor.The coolant that evaporative cooling is selected for use has high insulation, low boiling, safe, nontoxic, stable properties, as F-11 3 and the new fluorocarbons of substitute thereof.
With the evaporation cooling technique of height insulation low boiling point working medium place of water, air, hydrogen coolant, except all advantages that kept water, sky, hydrogen-cooled medium cooling.Also have following characteristics: (1) chilling temperature is low, Temperature Distribution is even more, no local hot spot; (2) insulation property height, physics and the chemical property of low boiling point working medium (the new fluorocarbons of F-11 3 and substitute thereof) are good, do not have similar water, hydrogen-cooled medium because of the accident that leakage damages insulation and explodes, and also do not have the oxide blocking problem; (3) cooling liquid that pours into plays the effect of part main insulation to the motor stator winding coil, can also suppress winding coil simultaneously effectively in groove and the corona discharge of end notch; (4) rotor has been cancelled the fan at axle two ends, has increased the distance sleeve between stator, the rotor, has reduced wind moussing loss, even and rotor cooling water takes place leaks and also can not influence stator insulation; (5) there is not water treatment system and hydrogen supply storage hydrogen storage equipment; (6) motor stator structure adopts globality airtight, and the parts in the bore of stator remain under the operating mode of cleaning always and move.Therefore, when unit was generally keeped in repair, stator also just need not overhaul.
Because the rotating speed height of rotor of steam turbo generator, the unit power material therefor is few, is the device that generates heat and relatively concentrate.Loss with regard to its each several part distributes, and for the highest, end construction spare and iron core take second place with winding in specific loss.Thereby Cooling Design should be at the different characteristics of zones of different and distinguish disposal.When stator adopts the full immersed type evaporative cooling, during with novel coolant place of water, hydrogen, air cooling medium, except the operation advantage and the operation safely and reliably that will keep the evaporative cooling turbo generator, also must solve following guardian technique problem: (1) is to the stator winding coil, the cooling circuit passage that cooling liquid must be arranged in stator core slot makes gas, liquid two-phase behind the liquid heat absorption ebullition, gasification moving unimpeded as far as possible; (2) air channel between stator core segment and core packet is the ventilation ducts place, must reasonably design the flow circuit loop structure of cooling liquid, (3) trim ring of end, stator core two ends must have feed liquor cool cycles passage up and down, and the stator core end is cooled off effectively.
Summary of the invention
The full immersed type circulation loop of vaporization cooling that the purpose of this invention is to provide a kind of stator of steam turbine generator.The present invention design is the problem that exists at the characteristics of stator of steam turbine generator structure and water, hydrogen coolant, under the little situation of the primary structure change of prior art stator, a kind of stator full immersed type circulation loop of vaporization cooling is provided, inject high insulation low boiling and the stable coolant of physical and chemical performance in the circulation circuit, in the stator of steam turbine generator chamber, form the self-loopa evaporative cooling, and guarantee its effectively cooling and operation safely and reliably.
As everyone knows, the stator core of turbo generator, winding coil and its fixed part and rotor are to constitute stator, the magnetic circuit of rotor, the magnet of circuit and the combination of conductor, are made up of many parts and member.Be noted that, stator of steam turbine generator full immersed type circulation loop of vaporization cooling of the present invention designs on prior art cooling structure basis, its stator core, winding coil, condenser, distance sleeve, stator pressing ring and fixed part and rotor are parts or the members that constitutes circulation circuit of the present invention, and they itself are not content of the present invention.But for the purpose of narrating conveniently, in application documents, they are narrated in the lump as part of the present invention.
Stator of steam turbine generator full immersed type circulation loop of vaporization cooling of the present invention, the parts of forming stator of steam turbine generator are contained in the bore of stator, comprise that stator core, stator core slot, stator winding coil, the unit two ends be made up of stator core segment are the trim ring and the tooth support at turbine end and exciter end that is stator core two ends.This circulation loop of vaporization cooling comprises the cool cycles branch loop of stator core slot, and the cool cycles between the stator core segment is divided the loop, and the cool cycles between stator core two ends trim ring and the tooth support is divided the loop.The cooling duct in the cool cycles branch loop between the cool cycles branch loop of described stator core slot and the stator core segment is communicated with.Cool cycles between the described stator core segment divides each cooling duct in loop UNICOM in parallel.Described stator core two ends trim ring and the cool cycles between the tooth support are divided each cooling duct UNICOM in parallel in loop.Inject cooling liquid F-11 3 or fluorocarbons HCFC-141b or CH3CFCl2 in the bore of stator, automatically flow in described three cool cycles branch loops until the cooling liquid that pours into, the tooth support at stator winding coil, stator core and two ends thereof and trim ring all are immersed in the cooling liquid.Condenser is contained in the support top, with the opening of its underpart and the opening UNICOM at bore of stator top.
The cool cycles of stator core slot of the present invention is divided in the loop, stator core slot be shaped as open slot, notch embeds slot wedge, the section perpendicular to its axis of groove is a rectangle, wherein filler strip under the straightway of order embedded groove heelpiece bar, winding coil and the slot wedge wedge is gone back filler strip between embeding layer between two winding coils; One deck fixed insulation layer is twined in segmentation on the main insulation of the winding coil straightway in the described embedded groove, makes it to fix as groove, and promptly the width of fixed insulation layer is identical with groove width, and the hop count of fixed insulation layer equals the hop count of iron core; The segmentation protrusion insulating barrier of insulating barrier that is fastened on main insulating layer, the position of protruding insulating barrier is just in time corresponding to the middle part of one section core packet, two recessed sections of protruding between the insulating barrier just in time divide return passage facing to the cool cycles between each core packet and the core packet, and the two UNICOM constitutes the self-loopa cooling passage of vapour-liquid two-phase cooling liquid.
Cool cycles branch loop between the stator core segment of the present invention is located at the ventilation ducts place between stator core segment and the core packet, and its iron core is an annular, and repeatedly assembled by the fan-shaped iron plate of N sheet, fan-shaped iron plate has several radial slots along the internal diameter limit; The sector channel iron plate is equipped with at the ventilation ducts place, this sector channel iron plate is on same of each identical shaped fan-shaped iron plate, many the contour little stripping and slicing projectioies of metal are arranged, the little stripping and slicing of these metals is radially arranged at interval in order, each ventilation ducts place plurality of sector passage iron plate of repeatedly packing into, the gap, interval of little stripping and slicing form cool cycles and divide return passage.
Cool cycles between stator core of the present invention two ends trim ring and the tooth support divides the loop in the form of annular discs substantially.Tooth support is contained in the stator core end face, forms cooling chamber between trim ring and the tooth support.Trim ring is contained on the support with bolt, and the presser feet of trim ring compresses tooth support.Have along the equally distributed radial direction through hole of circumference on the cylindrical of rounded trim ring substantially, end face has along the equally distributed through hole that parallels to the axis of circumference, and these through holes make the cooling chamber between trim ring and the tooth plate connect with outside.
Each cool cycles branch loop communicates with one another in the stator of steam turbine generator full immersed type circulation loop of vaporization cooling of the present invention.The condenser that is installed in the support top is an orthogonal formula condenser.
Stator of steam turbine generator full immersed type circulation loop of vaporization cooling of the present invention, for the gas-liquid two-phase fluid in the cooling liquid heat absorption ebullition, gasification process provides unimpeded mobile passage, gas-liquid two-phase fluid flowing in passage separately then finished by means of the condenser that is installed in the bore of stator top.
In the circulation loop of vaporization cooling of the present invention, the cool cycles branch loop of stator core slot circle in stator core evenly distributes along circumference, and their quantity equals the groove number of stator.Setting the pilot trench number is N.The cool cycles branch loop of (ventilation ducts) is M between stator core segment and the core packet, and the sum that M equals stator core segment subtracts 1, and they arrange one along the stator core axial length every an equidistance.Cool cycles branch loop between stator core two ends trim ring and the tooth support is two, lays respectively at the stator core two ends.The air inlet of the described condenser that is installed in the support top and liquid droping port are by the outlet UNICOM at flange and support top.
Pour into the evaporative cooling liquid medium of the low liquid boiling point of high insulation in circulation loop of vaporization cooling of the present invention and the generator unit stator chamber, as F-11 3, or the new fluorocarbons of its substitute, as HCFC-141b or CH
3CFCl
2Stator interior is normal temperature (40 ℃~90 a ℃) vapor cooling system.
Three cool cycles that reach between stator core two ends trim ring and the tooth support between steamer generator stator core groove of the present invention and the stator core segment are divided in the return passage, and cooling liquid can both flow unblockedly.So that the parts surface that reaches between stator core slot and the stator core segment between stator core two ends trim ring and the tooth support can both in time obtain sufficient cooling liquid infiltration.When generating set moves, in the winding of stator, iron core, trim ring, tooth support and other parts,, make to be filled in its coolant temperature rising on every side owing to energy loss produces a large amount of heats.When coolant temperature has reached and the corresponding saturation temperature of pressure, just come to life and absorb heat and become steam, thereby heat generating components is fully cooled off.Less than liquid, produce buoyancy and buoyance lift upwards because vapour density.Under the effect of acceleration of gravity, the steam that buoyance lift gets on runs into the condenser pipe of the condenser that is installed in the support top, heat is passed to after the time condensation water, being condensed into fluid drips falls in the bore of stator of bottom, and then the cool cycles that reenters is separately divided in the return passage self-loopa running that formation goes round and begins again.
Stator of steam turbine generator full immersed type circulation loop of vaporization cooling structure of the present invention, all advantages that not only have water, hydrogen and air cooling, and because of the F-11 3 that adopts low boiling, high-insulativity, good physical and chemical and the new fluorocarbons of substitute thereof as coolant, stop water, hydrogen-cooled medium fully and damaged the generation of insulation and hydrogen gas explosion accident because of leakage, saved water treatment system and hydrogen supply storage hydrogen storage equipment, and cooling liquid moves under airtight, evaporative cooling recurrent state.Cooling circuit particularly of the present invention, be that different characteristics according to loss distribution of motor stator each several part and zones of different designs, each position of motor stator is all cooled off effectively, thereby solved the local overheating problem of motor in running preferably.
Stator of steam turbine generator full immersed type circulation loop of vaporization cooling of the present invention at large-scale evaporative cooling turbo generator, the particularly supercritical unit of the above capacitance grade of 600MW, and in the generator as military ship power, all has broad application prospects.
Description of drawings
Fig. 1 is a stator of steam turbine generator full immersed type circulation loop of vaporization cooling unit general assembly schematic diagram of the present invention.
Fig. 2 be steamer generator stator core groove of the present invention and core packet between cool cycles branch loop cross-sectional view.
Fig. 3 be steamer generator stator core groove of the present invention and core packet between cool cycles branch loop longitudinal sectional view.
Fig. 4 is the insulation system figure of stator winding coil straightway of the present invention among Fig. 2.
Fig. 5 is the B-B cutaway view Amplified image of Fig. 4.
Fig. 6 is the structure chart that constitutes the sector channel iron plate in the cool cycles branch loop between the stator core segment.
Fig. 7 is the O-C cutaway view of Fig. 6.
Fig. 8 is an A partial enlarged drawing among Fig. 1, and the cool cycles between expression stator core two ends trim ring and the tooth support is divided loop structure.
Table 1 is to adopt 50MW stator of steam turbine generator immersion type evaporative cooling set grid-connection log data of the present invention.The variation of expression stator core and stator winding interlayer mean temperature.
Embodiment
Below in conjunction with the accompanying drawing illustrated embodiment content of the present invention is further described.
At first see also Fig. 1.Circulation loop of vaporization cooling of the present invention comprises the tooth support 80 of out frame 10, the end cap 20 of turbo generator, the condenser 30 that is installed in the support top, the distance sleeve 40 that is connected with support two ends end cap, stator winding coil 50 (it is made up of many coils), stator core 60 (it is overrided to form by many fan-shaped iron plates), trim ring 70 (each one at stator core two ends) and end, stator core two ends.Motor stator immersion type circulation loop of vaporization cooling is divided into three parts: the cool cycles branch loop 900 (Fig. 3) of (1) stator core slot, and it is arranged on the both sides of fixed insulation of the straightway of two embedded in each groove of circle in the iron core winding coils; (2) cool cycles between the stator core segment is divided loop 100 (Fig. 3), and it is arranged on along between the stator core segment of axis direction installation; (3) cool cycles between stator core two ends trim ring and the tooth support is divided loop 300 (Fig. 8), and it comprises uniform axial hole 813 on radial hole 811 that trim ring upper edge circumference is in the form of a ring divided equally and end face one circumference.
The cool cycles of stator core slot divides loop 900 as Fig. 2, Fig. 3, Fig. 4 and shown in Figure 5.It is combined by stator core 60 and slot wedge 902, and its horizontal section is a rectangle, and there is under one deck slot wedge wedge the straightway of filler strip 904, one deck bottom land filler strip 905 and two winding coils 50 between filler strip 903, one deck winding layers stator core slot shown in Figure 2 inside.Uniformly-spaced twine one deck fixed insulation layer 906 on the main insulation of the straightway of two winding coils 50, all adopt the wide insulating tape in the 30mm left and right sides.Twine (the about 0.5mm of thickness) insulating barrier projection 907 with the segmentation of the about 30mm of the axial length standoff distance left and right sides, and make insulating barrier projection number equal the stator core hop count.The straightway on such two winding coil 50 limits embeds in the stator core slot.Each insulating barrier projection 907 of the insulating outer layer looping of straightway is just in time corresponding to one section stator core segment 901.Concave part between two insulating barrier projectioies 907, also just in time and the passage in the cool cycles branch loop 100 between each stator core segment align, and make the two UNICOM.
Cool cycles between the stator core segment is divided loop 100, as Fig. 3 Fig. 6 and shown in Figure 7.It is combined into after being welded by the little stripping and slicing 112 of core packet 901 (by many fan-shaped iron plate 110 stacked forming), the fan-shaped iron plate 111 of passage and metal.Wherein the cooling duct is with the fan-shaped iron plate 111 of metal passage, arranges the sector channel iron plate 113 that is welded into as shown in Figure 6 and Figure 7 in order in its same side and the little stripping and slicing 112 of several metals.Laminate in the process at stator core, according to the cooling duct number of stator core, each passage is combined into plurality of sector passage iron plate 113.
Cool cycles between stator core two ends trim ring and the tooth support is divided loop 300, as Fig. 1 and shown in Figure 8.It is combined by trim ring 70 and tooth support 80, wherein in the ring-type collar wall of trim ring 70 along circumference with axially evenly have several radial holes 811 and axial hole 813, cooling liquid is is freely come in and gone out by radial hole 811 and axial hole 813.What be installed in that the condenser 30 at support 10 tops selects for use is the heat exchange condenser of common orthogonal formula structure.
Use example 50MW evaporative cooling turbo generator such as Fig. 1, Fig. 3 and shown in Figure 8 of technical solution of the present invention.Stator core 60 and stator winding coil 50 all are immersed in the cooling liquid.Rotor is an internal water cooling.Separate with fiberglass sleeve 40 between the interior circle of stator core 60 and the rotor.Condenser 30 is equipped with at the support top.The electric current output lead of stator is fixed by the outlet box of 6 special glass reinforced plastic sleeves and support bottom.Unit and outside feed liquor, tapping, leve monitor and the motor routine monitoring component lead etc. in addition that are connected.Pour into cooling liquid in the bore of stator after the unit installation.Subsequently, the cooling liquid that pours in the bore of stator flows into the cool cycles branch loop 900 of stator core slot automatically, and cool cycles branch loop 100 between the stator core segment and the cool cycles between stator core two ends trim ring and the tooth support are divided loop 300.
Table 1 is the log data of 50MW evaporative cooling turbo generator under various operating modes.From these record data as can be known, after the full immersed type evaporative cooling was adopted in the stator cooling, the temperature of stator core and winding coil interlayer was lower than the unit of the conventional type of cooling, meets the cooling technology requirement of turbo generator fully.
Table 1
Idle megavar | The mean temperature of stator core ℃ | The mean temperature of stator winding interlayer ℃ |
10 | 39 | 53 |
20 | 44 | 54 |
30 | 45 | 54 |
40 | 45 | 54 |
50 | 48 | 57 |
-10 | 46 | 50 |
-5 | 42 | 50 |