Evaporation cooling circulation unit in stator windings of turbogenerator
The present invention relates to a kind of device with the cooling large-sized Stator Coil of high insulation low-boiling point liquid medium circulation inside.
In the prior art, the cooling of Stator Coil inside adopts water as coolant usually.Water enters winding inside by an end (exciter end) of support through charge for remittance circulation, flows out from the other end (turbine end), and the outlet water temperature is controlled at below 90 ℃.This type of cooling is to utilize " specific heat " of flowing liquid medium to take away the heat that the inner copper loss of winding is produced.Because the boiling point of water under an atmospheric pressure is 100 ℃, therefore, aqueous medium can not produce vaporization and the stagnant phenomenon of vapour in winding inside.But the water high and unsettled medium of physical and chemical performance that is a kind of conductance, in case from winding inside to external leakage, will destroy the major accident of winding insulation or phase fault.This accident is particularly frequent and serious in running time long internal water cooling unit.
Because the water cooling medium is the hidden danger that causes major accident, so seek new coolant, studies new cooling technology, the requirement that improves running reliability of motor becomes more and more urgent.At present domestic and international many motor manufacturing firm is all in the research and development of carrying out novel cooling technology.One of approach is that employing is not burnt, non-conductive, nontoxic liquid or gas is replaced the water-cooled medium.As states such as Russia, Japan, Switzerland and Canada, will wait liquid or the gas that employing does not fire on the level capacity generator to cool off more than the 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 to utilize the principle of liquid cooling medium vaporization heat absorption to come cooling motor, and the coolant of selecting for use has high insulation, low boiling, safety, stable properties, as F-11 3 and the new fluorocarbons of substitute thereof.Novel coolant is used for the inner evaporative cooling of Stator Coil, does not still have report at present.Substitute stator winding internal water cooling medium with height insulation low boiling point working medium, except all advantages that kept internal water cooling, also have following characteristics: (1) Temperature Distribution is more even; (2) the insulation property height of low boiling point working medium (the new fluorocarbons of F-11 3 and substitute thereof), good physical and chemical does not have similar internal water cooling because of leakage damages the fault of insulation, does not have the oxide blocking problem yet; (3) there is not water treatment system; (4) cooling liquid is enclosed in the circulating device that comprises winding, and the disposable amount of pouring into is few.
But, because large turbo-type generator stator winding copper loss is big, account for about 0.25%~0.5% of unit capacity, many coil inner cooling paths of forming winding are long and narrow, embed in the iron core more than the parallel branch and with different angular distribution, end diameter is big, the very uneven characteristics of each branch road distribution, so adopt evaporative cooling when stator winding is inner, when substituting the internal water cooling medium with novel coolant, ensure that generating set moves safely and reliably, must solve following key technical problem: the circulating device of cooling liquid and each inner cooling path of winding are complementary, make the isostasy of each branch road of stator winding liquid outlet; 2. must control the position of the heat absorption evaporation point of cooling liquid in conductor.
The objective of the invention is at the characteristics of Stator Coil structure and the problem of using the internal water cooling medium to exist, under the little situation of stator winding inner-cooling structure change, a kind of evaporation cooling circulation unit is provided, this device adopts high insulation low boiling and the stable coolant of physical and chemical performance, in Stator Coil internal implementation evaporative cooling, and ensure that it moves safely and reliably.
Be noted that Stator Coil and connecting tube thereof are the operating links of apparatus of the present invention, and do not belong to content of the present invention.For sake of convenience, the part as apparatus of the present invention is narrated in the lump in application documents.Stator winding is the combination that constitutes the conductor of stator circuit, is made up of many coils.
Evaporation cooling circulation unit in stator windings of turbogenerator of the present invention (abbreviation circulating device), the stator winding that comprises turbo generator, the pipeline that connects winding coil, the support two ends are the trim ring of turbine end and exciter end, the charge for remittance ring of an end such as exciter end wherein, and then, apparatus of the present invention comprise a pressurizer with a plurality of condensing units, a cooler, the height insulation low boiling cooling liquid that pours in the loop, and circulation magnetic drive pump that makes the cooling liquid shuttling movement, the corresponding connection of inner cooling path liquid outlet of the liquid feeding end of described pressurizer and each coil of stator winding, the inlet UNICOM of the liquid outlet of described pressurizer and described cooler, the liquid outlet of described cooler connects the input of described circulation magnetic drive pump, this circulation magnetic force delivery side of pump and the inlet UNICOM that is installed in the charge for remittance ring on the support other end such as the exciter end trim ring, the delivery port of described charge for remittance ring connects with the inlet of each inner cooling path of described stator winding coil.
Pressurizer in the circulating device of the present invention is a ring-type, semi-ring housing by two metals combines, its radial section is a rectangle, its inside is separated into adjacent a Semicircular remittance liquid passage and a condensation cavity vertically with the metal axial dividing plate, described condensation cavity is divided into N/2 condensing unit (N equal number of stator slots) along circumference with the condensation cavity with metallic radial dividing plate with holes again, many metal condenser tube run through the hole on the metal partion (metp) between described condensing unit in proper order, the below of the outer side panel of each condensing unit all is provided with a liquid inlet joint, each condensing unit porosely on the interchannel axial dividing plate of liquid communicates the two with converging, so constitute the in-line condenser of semicircular, with two threeway members two semi-ring housing butt joints are joined together then, as the water inlet and the delivery port of the secondary cooling water of condenser, two Semicircular remittance liquid passages respectively have a liquid outlet to described two threeway members respectively.
Circulating device of the present invention is a split-type structural, and described pressurizer is installed on the trim ring of end of support such as turbine end, or is installed on the limit section of support, and cooler and circulation magnetic drive pump are installed near the base outer edge.
In the circulating device of the present invention, the liquid feeding end of pressurizer is a plurality of liquid inlet joint, and the liquid outlet of each inner cooling path of they and stator winding coil links with isolated pipe.The liquid outlet of described charge for remittance ring connects with isolated pipe with the inlet of each inner cooling path of stator winding coil.The liquid outlet of described pressurizer and the inlet of described cooler metallic conduit UNICOM.
Circulation magnetic force in the circulating device of the present invention, its inlet is with the fixing UNICOM of the delivery outlet of flange and cooler, and its liquid outlet is with metallic conduit and be installed in the inlet UNICOM of the charge for remittance ring on the support other end such as the exciter end trim ring.
Inject high insulation low boiling point working medium in its evaporative cooling loop of circulating device of the present invention, as F-11 3 and the new fluorocarbons of substitute thereof, the circulation magnetic drive pump makes cooling liquid shuttling movement in the loop.Stator winding inside is normal temperature (40 ℃ to 90 ℃) vapor cooling system, the partially liq of outflow and the mixture of gas divide secondary to cool off to the cooling liquid heat absorption of winding inside is back, and two control points are arranged: the one, first control point of boiling evaporation point position after this device balance is absorbed heat with the cooling liquid of controlling stator winding inside, this point is positioned at the inner cooling path liquid outlet of each coil of stator winding and the connection place of each liquid inlet joint of pressurizer; The 2nd, this device is regulated second control point of supplying with the chilled liquid temperature of stator winding inside with control, and this point is positioned at the connection place of the liquid outlet and the circulation magnetic drive pump of cooler.
When evaporation cooling circulation unit of the present invention is worked, start the circulation magnetic drive pump, the cooling liquid in the circulation circuit flows into the charge for remittance ring through pressurization, advances the inner cooling path of each coil of winding again through the insulation channel flow.When the stator winding of turbo generator has electric current to pass through, because of copper loss makes the conductor heating, the cooling liquid that enters the winding coil inner cooling path absorbs the heat that copper loss produces, and temperature raises gradually, when its temperature reaches capacity the pairing temperature of pressure, just change the physical state boiling and be vaporized into gas.
Height is insulated lower boiling liquid cooling medium when being used for the evaporative cooling of stator winding inside, desire to obtain effective, stable, reliable cooling effect, must control the evaporation point position of each coil inside coolant heat absorption back boiling vaporization of winding, this is one of apparatus of the present invention designs key technology that will solve, and the pressurizer in apparatus of the present invention is exactly for this reason and design.As everyone knows, the distribution of large turbo-type generator stator winding coil is very inhomogeneous, pour into cooling liquid itself in the circulation cooling circuit and produced the pressure differential of about 0.045MPa therein, so cause in numerous stator winding coils, cooling liquid distributes and does not wait, the volume size inequality causes the cooling liquid of each coil inside of stator winding, and the front and back position of evaporation point is inconsistent along the axial length.If the cooling liquid medium is too near from liquid feeding end in the position of winding coil interior evaporation point, conductor inside will produce the stagnant phenomenon of vapour, causes the winding local overheating, so that influence the gentle effect of cooling water of motor integral body.
In being provided with the circulating device of the present invention of pressurizer, the pressure differential that cooling liquid produces in the circulation cooling circuit, by the N in the pressurizer condensing unit five equilibrium, the pressure that cooling liquid produces in each condensing unit is equal substantially, therefore, it is also equal substantially to enter the flow and the flow resistance of the cooling liquid in each coil of stator winding.During the circulating device operation, be with heat to flow out after the cooling liquid heat absorption of winding coil inside, and enter pressurizer with the mixture of the cooling liquid that is gaseous state and liquid admixture, these mixtures at first become liquid by the condenser condenses in the pressurizer, and the hole by axial dividing plate top enters remittance liquid passage then.,, just can control the position of the boiling evaporation point after winding coil internal coolant body absorbs heat effectively here, the control at Here it is first control point as long as regulate the flow and the operating pressure of secondary cooling water of the condenser of pressurizer.Then, the cooling liquid that flows out from the remittance liquid channel outlet of pressurizer, enter through piping and to carry out second level cooling in the cooler, enter the control at second control point, promptly regulate the flow of the secondary cooling water of cooler, the temperature of control cooling liquid is about 40 ℃, send the circulation magnetic drive pump then to, cooling liquid enters the charge for remittance ring after the pressurization of circulation magnetic drive pump, enter winding coil inside at last, has so just formed a circular flow that goes round and begins again.
Fig. 1 is evaporation cooling circulation unit in stator windings of turbogenerator of the present invention and connects schematic diagram.
Fig. 2 is the pressurizer structure chart of apparatus of the present invention.
Fig. 3 is the pressurizer local I structure enlarged drawing among Fig. 2.
Fig. 4 pumps into the temperature distributing curve diagram along conductor length that records when high insulation low boiling point working medium adds the electric current heat run to simulation winding inside.
Fig. 5 is to 200MW Stator Coil internal water cooling line rod, pumps into high insulation low boiling point working medium, adds the temperature distributing curve diagram along conductor length that the electric current heat run records.
Below in conjunction with the accompanying drawing illustrated embodiment, content of the present invention is further described.
At first see also Fig. 1.Evaporation cooling circulation unit of the present invention comprises the stator winding 60 of turbo generator, and it is made up of many coils, and the feed tube 50 and the drain pipe 70 of coil all adopt insulated tube; One pressurizer 10, a cooler 20, a circulation magnetic drive pump 30 usefulness metallic conduit orders link, the inlet UNICOM of the output of circulation magnetic drive pump 30 and charge for remittance ring 40, many liquid outlets of charge for remittance ring 40 connect with the inlet of the inner cooling path of the many coils of stator winding.The whole circulation device is a split-type structural, pressurizer 10 is installed on the trim ring of an end turbine end of support or is installed on the limit section of support (expression on the figure), and described cooler and circulation magnetic drive pump are installed near the base outer edge (expression on the figure).
Pressurizer 10 of the present invention is a metal weldedstructure, as shown in Figures 2 and 3.It is combined by the semi-ring housing of two metals, its radial section is a rectangle, the semicircular housing is welded with metallic plate 141,142,143,144 amalgamations, and its inner chamber axially is separated into a remittance liquid passage 16 and a condensation cavity 15 with metal axial dividing plate 17 along it.This condensation cavity 15 is separated into N condensing unit 13 by metallic radial dividing plate with holes 11 grades again, and many (being depicted as 5 on the figure) metal condenser tube 12 orders run through between condensing unit the hole on the dividing plate 11 radially; A liquid inlet joint 18 all is equipped with in the below of the outer panel 144 of each condensing unit 13, each condensing unit all has a hole 19 to make the two UNICOM with the top of the interchannel axial dividing plate 17 of remittance liquid, so constitute the in-line condenser 13 of semicircular, with two three way type members 101 and 103 two semicircular housings are connected into the pressurizer of a ring-type, 101 and 103 respectively as the water inlet and the delivery port of the secondary cooling water of condenser, with insulated tube each liquid inlet joint 18 corresponding connections on the inner cooling path liquid outlet of each coil of stator winding and the pressurizer 10,102 and 104 liquid outlets that converge the liquid passage about respectively in the pressurizer.What cooler 20 was selected for use is common heat exchange cooler.Circulation magnetic drive pump model is the 32CQ-15 type.
The characteristics and the effect of circulating device of the present invention tested and illustrated along the temperature distribution history (Fig. 4 and Fig. 5) that the conductor length each point records to two following stator winding fever model.
Stator winding fever model experiment 1
According to 200MW steamer generator stator core, winding coil size, set up stator winding experiment fever model.The simulation winding is 8.5 meters by 36 length, diameter is 6 millimeters, wall thickness is that 36 simulation winding coils (60) that 1 millimeter copper tube constitutes are formed, along the circumferential direction whenever be separated by 10 ° with the stator core internal diameter size and settle a winding coil (60), winding coil (60) two connects into loop shown in Figure 1 with charge for remittance ring (40) and pressurizer (10) respectively with insulated tube (50) and (70).The inner cooling liquid of winding coil (60) is selected F-11 3 for use.To the heating of stator winding coil (60) galvanization, start circulation magnetic drive pump (30) simultaneously, the electric current stepping is 0.8I
H1, 0.9I
H1, 1.0I
H1, 1.05I
H1, 1.10I
H1(I
H1Be 260 peaces).When whenever adding the electric current of a class, switched on one hour, treat that the stable and cooler fluid temperature reading of pressurizer (10) operating pressure among Fig. 1 is stabilized in about 40 ℃ after, measure the each point temperature reading by the multi-parameter scan tester.Figure 4 shows that one of them winding coil (60) when different electric current along conductor length each point temperature distributing curve diagram.From curve chart as can be known, after evaporative cooling was adopted in the inner cooling of winding coil, the temperature difference at two ends all in 40K, met the cooling technology requirement of turbo generator.
Stator winding fever model experiment 2
According to 200MW steamer generator stator core, winding size, set up stator winding experiment fever model.6 200MW stator of steam turbine generator internal water cooling line rods that winding coil (60) adopts certain electrical machinery plant to provide, with the five equilibrium arrangement along the circumferential direction of stator core internal diameter size, winding coil (60) two uses insulated tube (50) and (70) to connect into loop shown in Figure 1 with charge for remittance ring (40) and pressurizer (10) respectively.Cooling liquid in the winding coil (60) is selected F-11 3 for use, to the heating of stator winding coil (60) galvanization, starts circulation magnetic drive pump (30) simultaneously, and the electric current stepping is 1.0I
H2, 1.10I
H2, 1.20I
H2(I
H2Be 4300 peaces), when whenever adding the electric current of a class, switch on one hour, treat that pressurizer (10) operating pressure among Fig. 1 and cooler fluid temperature reading are stablized after, measure the each point temperature reading by the multi-parameter scan tester.Fig. 5 be one of them winding coil (60) when different electric current along conductor length each point temperature distributing curve diagram.This curve chart shows that after evaporative cooling was adopted in the inner cooling of winding, the temperature difference at winding coil two ends all in 40K, met the cooling technology requirement of turbo generator.
Evaporation cooling circulation unit in stator windings of turbogenerator of the present invention, all advantages that not only have internal water 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 similar internal water cooling fully and damaged the generation of the fault of insulation because of leakage, saved water treatment system, there is not the oxide blocking problem yet, and because airtight, the evaporative cooling circular flow of cooling liquid, the disposable amount of pouring into is few, and operating cost is low.Pressurizer in the circulating device particularly of the present invention is kept in balance the pressure of each path of winding liquid outlet of turbine end stator winding of generator, in winding, flow out the mixture condensation that is the gas-liquid state, again by regulating the secondary cooling water flow and the operating pressure of condenser, thereby realized the control of the cooling liquid heat absorption back boiling evaporation point position of stator winding coil inside, and,, height insulation low-boiling point liquid coolant provides guarantee for being used for the inner transpiration-cooled safe and efficient operation reliably of Stator Coil to the control of chilled liquid temperature.
Circulating device of the present invention, at the large-scale full liquid cooling turbo generator of developing from now on, cold unit in the particularly super-huge turbo-generator of the above capacitance grade of 1000MW, and motor stator winding requires all has broad application prospects.