CN1012444B - Impingement cooled transition duct - Google Patents

Abstract

A transitive air inlet channel in an advanced heavy gas turbine engine is cooled by impact jet streams formed by holes in a sleeve pipe at an interval to a surface to be cooled. Waste impact air led by the sleeve pipe to a combustion apparatus is subsequently mixed with fuel and combusted, or the sleeve pipe cools the combustion apparatus. The distance between the sleeve pipe and the surface of the transitive air inlet channel varies to control the transverse flow velocity of the waste air and reduce pressure loss caused by transverse flow. The hole diameter varies with the jetting distance and the transverse flow velocity. The intensity of impact cooling is changed to compensate a variable internal thermal load by utilizing the combination of the variation of the distance, the hole diameter and the interval, and ideal temperature distribution is generated on the surface of the transitive air inlet channel according to design requirements.

Description

Impingement cooled transition duct

The present invention is relevant with gas turbine engine, the concrete relevant device that is used for cooled transition duct, and this transition duct from a firing unit, is introduced a turbine stage to hot combustion gas in advanced heavy duty gas turbine engine.

Big heavy duty gas turbines is using the cylindrical firing unit level of some parallel runnings traditionally, produces the hot combustion gas of energization, introduces first turbine stage of motor.The preferably hot combustion gas of annular that first turbine stage is accepted.A transition duct is arranged, be placed between each the firing unit level and first turbine stage, the gas flow field from the ejection of each firing unit, cylindrical from is roughly changed into the part of an annular.So all the air-flow of transition duct ejection produces desirable annular airflow.

As known, the heating power that heat engine may be obtained is renderd a service, and depends on the maximum temperature of its working fluid, as is gas turbine, then depends on the hot combustion gas of discharging the firing unit level.The maximum safety temperature of hot combustion gas is subjected to the restriction with the operating temperature limit of the metal parts of this hot contacts fuel gas, and depends on these parts are cooled to ability below the hot gas temperature.The cooling task of advanced heavy gas engine transition duct, the problem that just the present invention is directed to is inconvenient, because known now cooling means, if not scarce capacity is to be attended by the cost that can't bear.

In a traditional heavy duty gas turbine engine, whole outer surfaces of transition duct, the air of the relative low temperature that the contact gas compressor is discharged, gas compressor provides whole air-flows to gas turbine.Cause passive cooling from the air-flow of transition duct appearance flows into combustion device.Some part of transition duct appearance is subjected to the goodish cooling of passive cooling, but the cooling of other part is then very poor.And the poorest part of cooling of transition duct appearance generally is the zone at the bottom of the structural strength, also is that hot combustion gas heats higher zone inside.For the damage that prevents that prohibitive metal temperatures from causing, the high exhaust temperature of firing unit must be subjected to the restriction of the metal maximum safety temperature in the poorest zone of transition duct cooling.In order to promote to improve the thermal efficiency, the delivery temperature of heavy gas turbine firing unit is existing to be improved, and has adopted the means in the relatively-high temperature zone of various positive cooled transition ducts.In an advanced heavy duty gas turbines, the delivery temperature of firing unit, more quite a lot of than the temperature height about 2000 degree of common heavy duty gas turbines, all surfaces of transition duct must have positive cooling, to keep the permissible level of metal temperature.

The known method of cooling combustion device wall, the exhaust that makes gas compressor process from the firing unit wall along its internal surface guiding, forms a film of defending hot combustion gas directly to contact then.This arrangement can make the firing unit wall, works under the low considerable temperature of specific heat combustion gas.This film cooling means has been used for the limited area of transition duct, especially on the zone of above-mentioned cooling difference.Yet the application of this film cooling method has been subjected to obtaining the quantitative limitation of the air of specializing in cooling combustion device and the use of transition duct wall.This amount is on the typical case, and can only reach can be for below 1/3rd of total amount of the air-flow of firing unit use.In advanced person's heavy duty gas turbine engine, almost need all can do the air that the film cooling is used, the cooling combustion device wall, the air that can be used for the cooled transition duct wall is then considerably less.This restriction of cooling blast supply, be because the pact of the total air flow of firing unit half, need be used to carry out the abundant burning of fuel, air-flow in addition 1/4th need be used to water down the hot combustion gas that firing unit is discharged, its setting, meet first turbine stage for raising the efficiency, prolongation component life is required.This ratio can be according to the design of concrete employing and varied slightly, but various practical obstacle are arranged, and this ratio has bigger departing from.

Had another kind to be used for the cooling technology of cooled transition duct outside, be to use a striking plate, baffle plate or sleeve pipe leave short distance of transition duct outer surface and place.Impacting sleeve pipe has the array of an eyelet, and the air that gas compressor is discharged passes through from the inside, produces a jet array, and the transition duct outer surface is collided and cooling.

U. S. Patent the 3rd, 652 in No. 181, has disclosed a kind of impact cooling technology of transition duct, and it impacts sleeve pipe only around the part of transition duct.Impacted the useless impinging air behind the surface that needs cooling, flow through, arrived in the hole on the transition duct at the transition duct outer surface with in impacting between the sleeve pipe.By the air and the hot combustion gas mixing in these holes, and just reduce hot gas temperature, reduce this part metal temperature of turbine blade thereby help in turbine blade base regions front.This method depends on the maximum safety temperature of the heat transfer rate and the metal of combustion gas, can use than the film cooling and use less cooling air, keeps the metal temperature of allowing, and can cool off combination with film, further reduces metal temperature.But, even on transition duct, adopt to impact cooling and film cooling combination, in advanced heavy duty gas turbines, need cooling air more than can getable cooling air.

Other relevant combustion gas turbine combustion elements impact announcements of cooling, can be from U. S. Patents the 4th, 339, see in No. 925.Though gas turbine combustion elements type that this patent is cooled off, with the present invention at different fully, this patent has disclosed the typical factor that impacts cooling system.Disclosed a housing, last perforation array, cooling air passes through from the inside, impacts in hot fuel chamber towards firing unit.A kind of embodiment has been done diagram and narration, and its impinging air flows along hot fuel chamber, participates in gas process at last.There is a kind of restrictor to disclose, helps to spray the space of air between hot combustion gas shell and porous.This patent is recognized: the number of inlet hole and antibody leave the spacing of hot fuel chamber, have represented some parameters, can be used for by environmental requirement, produce cooling effect.

As U. S. Patent the 3rd, 652, No. 181 and 4,339, No. 925 disclose, in the prior art field, the impact cooling of combustion elements can consume the air-flow that a part is distributed for combustion process, perhaps,, be used for combustion process subsequently again the air that is used to cool off a combustion elements with the firing unit series running.This to transition duct series connection cooling, be exactly the present invention at target.

Based on being familiar with combustion gas turbine design skill person reason in common knowledge, the air that gas compressor is discharged, suppress by opening on the firing unit and fuel mix and when burning, produce thereupon that pressure falls or pressure consumption.Be exactly that watering down of the film cooling that can promote firing unit and air stream falls in this pressure, thereby the temperature graph of the air of discharging from fuel-device to the initial stage is finalized the design.According to the typical case, this pressure fall compressor discharge pressure 2 percent and four between, and, force down it for the reason of maintaining heat efficient as far as possible.If pressure falls too low, fuel and air mixing are not good so, as a result incomplete combustion.If pressure falls too high, the thermodynamic efficiency of combustion gas turbine descends so.

In order to realize impacting cooling, need a pressure and fall by impact sleeve pipe or baffle plate, use and suppress cooling air, under quite high speed, from eyelet, pass through, with the heat transfer rate that obtains to require.Generally speaking, high rate of cooling obtains from high pressure drop.Therefore can see, transition duct adopts and impacts cooling in series air current is arranged, will cause the extra pressure of combustion system to fall, do not remain on the alap level if this pressure is not fallen, the thermal efficiency that may cause descends, greater than increasing by improving the obtained efficient of firing unit delivery temperature.

The pressure that impacts cooling system falls, and results from two factors basically.At first be to need a pressure to fall the air that quickens by the impact collar aperture, cause the surface that jet flow is impacted needs cooling.Therefore next factor is more unpredictable, impacting on other the known applications of cooling, is mostly ignored.

If requirement will utilize in firing unit with the impinging air of crossing, and it must be collected, and send into firing unit then.Collection ought to be carried out between the outer surface that impacts sleeve pipe and transition duct, was appreciated that, if collecting near the firing unit place, because the air of collecting increases, air velocity necessarily constantly increases.Second factor of generation falls in pressure, is because require each increment of useless impinging air is quickened again, reaches the speed near the air of firing unit.

Impact the localized heat transfer amount size in the cooling system, depend on many parameters.These parameters specifically comprise the performance of cooling air, impact the distance between sleeve pipe and the transition duct, pore size, the form of spacing and array, impinging air jet speed, and air is perpendicular to the flow velocity of jet stream, the uprush that causes when collecting useless impinging air.

Be appreciated that influencing the heat output size is a large amount of with the parameter that the overall pressure of impact cooling system falls.What the present invention is directed to is the complete cooled transition duct of advanced heavy duty gas turbine engine, the correlation of these parameters in it successfully designs.

By an air jet that perforate forms on the striking plate, must pass the space of striking plate and surface to be cooled isolation, and must have enough speed and enough amounts to collide surface to be cooled, realize the cooling action that needs.When only relating to a jet flow, jet flow impacted to perform an analysis be quite simple.Yet when using the jet flow array, after impacting, a jet flow of impinging air leaves away, intercepted and captured between surface to be cooled and striking plate, certainly will produce a tranverse air flow, disturb the cooling action of other jet flows, especially those jet flows in those downstreams on the direction that impinging air must pass through for the outflow confined space.Just: the lateral flow of the air by the space between an eyelet and the surface to be cooled, the jet flow that may stop eyelet to produce reaches surface to be cooled, perhaps reduces the validity of the jet flow any part on the surface that may reach to be cooled.The actual cooling effect of a jet flow array is difficult prediction, thereby can only derive by experience.

The speed of cross flow is big more, laterally disturbs big more to the validity of air jet.When use impacting the cooling intake duct, all impinging airs must between transition duct and the striking plate to outflow, when horizontal air flow outlet, amount and speed increase regularly.Speed increase the validity that may partially or completely destroy other impingement flow in jet flow downstream.Perhaps because of this reason, the apparatus of the use impact jet flow cooled transition duct (or hot fuel chamber) in the skill field is arranged earlier, useless impinging air is penetrated the inside of transition duct.As discussed above, by this inefficient the use, be available cooling air irrational for the design of the heavy gas turbine of advanced person.

Therefore, purpose of the present invention is to propose a kind of impingement cooled transition duct that is used for combustion gas turbine, can overcome the shortcoming that has earlier in the skill field, improves the cooling of transition duct.

Particularly, the present invention proposes a kind of impact cooling system, for whole transition ducts uses of gas turbine engine, can do specific cooling and distribute according to the designing requirement of transition duct.

The present invention also proposes a kind of impact cooling system of transition duct, wherein has a perforation size at least, impacts the eyelet spacing on the cooling collar, and impacts the spacing between sleeve pipe and the surface to be cooled, changes with specific surface cool regularly.

The present invention further proposes a kind of impact cooling system of gas turbine engine transition duct, in order to reduce cross-flow speed, thereby the pressure that reduces to impact cooling collar falls, and the spacing of impacting between sleeve pipe and the transition duct increases on the downstream of impinging air lateral flow direction regularly.

The present invention further proposes the impact cooling of the whole transition ducts of a kind of advanced heavy duty gas turbines, its perforation size and eyelet are in the distance of impacting on the cooling collar, and the distance of impacting between sleeve pipe and the transition duct surface changes regularly, fall to reduce the impacting desired pressure of cooling, thereby increase the thermal efficiency of gas turbine engine.

The present invention proposes a kind of impact of gas turbine engine transition duct cooling, it impacts the perforate on some part of sleeve pipe, greater than the perforate on the remaining part, thereby provide the jet flow of high mass flow, transition duct be can run through and spacing bigger between the sleeve pipe and bigger air cross flow impacted.Spacing between these macropores preferably changes with respect to the spacing between the aperture, to press the designing requirement of transition duct, obtains the impact intensity of cooling of requirement.

The present invention further proposes a kind of impact cooling and gas flow divider system, can accurately control the pressure that impacts cooling and fall, and can reduce the firing unit stream pressure that the upstream falls in firing unit pressure and fall.

In brief, the present invention proposes a kind of impact cooling of advanced heavy duty gas turbine engine transition duct, transition duct is by impacting the jet flow cooling, and jet flow is by having the eyelet on the sleeve pipe of a distance to form with surface to be cooled.Sleeve pipe has certain structure shape, and useless impinging air is carried to firing unit, this air be can be used for and fuel mix and burning afterwards, or be used for the cooling combustion device.Impact the distance variableization between sleeve pipe and the transition duct surface, with the speed of the lateral flow of controlling useless impinging air, to reduce because the pressure loss that lateral flow causes.The sectional area of eyelet can change, and throws under the speed of various distances and lateral flow impacting jet flow.Generally speaking, the macropore sectional area is used for big distance.Because in the intersection of firing unit and transition duct, the amount of useless impinging air is increased to a numerical value the highest, impacts the distance between sleeve pipe and the transition duct, is increasing regularly on the direction of firing unit.Can utilize distance, the combination that aperture and distance between borehole change changes the intensity of impacting cooling, with the interior thermal force of compensate for variable, and by designing requirement, on the surface of transition duct, produces the temperature distribution that needs.Make optimization for above-mentioned variation and select, the pressure that reduces air-flow in the front of combustion system falls, and just can obtain the intensity of cooling that needs by designing requirement.

According to one embodiment of the invention, the impingement cooling device on a surface of a kind of cooling has been proposed, the surface is in the compressed environment, and a striking plate is arranged in the device, stands away with this surface, and some eyelets are arranged on the striking plate; There is device to produce a pressure that crosses striking plate and falls, so impact jet flow towards the surface of each eyelet generation, eyelet has a cross section, and spacing is arranged between the eyelet; On striking plate, have at least one should distance, the variation of this cross section and this spacing is with the cooling on the control surface.

Characteristics that propose according to the present invention, be provided with the impact cooler on a surface of a cooled transition duct, transition duct is placed between the turbine stage of a firing unit and a gas turbine engine, transition duct is placed in the pressurized air pumping chamber, an impact sleeve pipe is wherein arranged, the corral transition duct also has a distance with it, form the airflow capacity between the two, on the impact sleeve pipe, some eyelets are arranged, each of these some eyelets, a cross section is arranged, between the adjacent eyelet spacing is arranged, the end that a sealing is arranged at the turbine end of airflow capacity, the firing unit end of airflow capacity has an outlet, an air-flow sleeve pipe corral firing unit is arranged, on an end of putting up outlet of air-flow sleeve pipe, a flaring inlet part is arranged, make therebetween the aerodynamic force shape of amassing wealth by heavy taxation, by the aerodynamic force shape of amassing wealth by heavy taxation, to the firing unit airflow flowing, the handlebar outlet pressure is reduced to the following effect of pumping chamber's pressure, therefore, cross a pressure that impacts sleeve pipe and fall, produce one impact jet flow that sprays to transition duct from each eyelet, and have a distance at least, the cross section, and spacing, on the impact sleeve pipe, change the cooling on the control surface.

Another characteristics of being carried according to the present invention, be provided with an impact cooler, the surface that quilt encloses that cooling is formed by a wall, this wall and a transition duct are fixed, transition duct is surrounded by an impact sleeve pipe, wall passes through in an opening that impacts sleeve pipe, transition suction tude and impact sleeve pipe are placed in the pumping chamber, the effect that forms a forced air environment is arranged, impacting in the cooler has an impact in the wall to insert body, have between the flat and besieged surface distance is arranged, on flat, some eyelets are arranged, have to produce to cross and impact the device that the pressure of inserting body falls, thereby each eyelet produces an impact air-flow that sprays to besieged surface, eyelet has a cross section, spacing is arranged mutually between the eyelet, and besieged surface has a film cooling hole by transition duct at least, discharges and impacts the useless impact cooling air of inserting between body and the besieged surface, cross section and spacing change the cooling on the control surface on demand on flat.

The purpose of the above and other of the present invention, characteristics and advantage are read in conjunction with the accompanying drawings and can be understood just that hereinafter in the accompanying drawings, similar elements indicates with the identical number of marking on a map.

Fig. 1 is for adopting firing unit and the transition duct that skill field cooling method is arranged earlier, and figure is the cylinder that broken section is arranged.

Fig. 2 analyses and observe for plate to be cooled and striking plate, when this paper narrates air cross flow impact jet flow Effect on Performance, will quote to some extent.

Fig. 3 A is the firing unit and the transition duct of the impact cooling method of employing one embodiment of the invention, and figure is the cylinder that broken section is arranged.

Fig. 3 B is for adopting the firing unit and the transition duct of the impact cooling method in another embodiment of the present invention, and figure is the sketch that broken section is arranged.

Fig. 4 is the enlarged view of the airflow capacity exit portion of Fig. 3.

Fig. 5 is for analysing and observe along of V among Fig. 3-V line.

Fig. 6 is for analysing and observe along of VI among Fig. 5-VI line.

Fig. 7 is for analysing and observe along of VII among Fig. 6-VII line.

At first referring to Fig. 1, wherein with numbers 10 parts generally representing to have earlier the gas turbine engine in the skill field.Some firing units are arranged in the gas turbine engine 10, around the longitudinal axis of motor, be evenly distributed, only show a firing unit among the figure.In a kind of pattern of gas turbine engine 10, ten firing units 12 have been used.Fuel and elementary combustion-supporting air spray into firing unit 12 by fuel burner 14.Fuel and air are burnt in firing unit by spark plug 16 igniting.Hot combustion products and excessive heat air by transition duct 18, arrive turbine stage 20 suction ports.

Firing unit 12 and transition duct 18 are placed in the pumping chamber 22, and pressurized air is supplied with to the pumping chamber from the blower outlet 24 of gas turbine engine 10.The pressurized air that blower outlet 24 is sent along the Surface runoff of firing unit 12, is passed through the lip-deep traditional hole of firing unit (figure does not show), the inside of introducing firing unit 12.Introduce the air in the firing unit 12 like this,, participate in combustion reaction, or be directed as a cooling air film along firing unit 12 internal surfaces in the downstream of fuel burner 14.Some pressurized air can be used to the heat of dilution combustion gas, controls the useless stream temperature of firing unit 12, and determines figure to temperature.An air-flow sleeve pipe 26 can be set, around firing unit 12, to improve air flowing along the firing unit wall.

The outer surface of transition duct 18 is used from blower outlet 24 to the pressurized air that firing unit 12 flows, and does the convection current cooling.The inner radial surface 28 that a transition duct 18 is arranged has been placed on direct change of flowing out in the compressed air of direction from blower outlet 24.Particularly, a part 30 of the inner radial surface 28 of the firing unit end 32 of close transition duct 18 is cooled off fully.And the part 34 of nearer turbine end 36 inner radial surface 28 is then cooled off relatively poor.By contrast, on the radially-outer surface 38 of transition duct 18, but stoped the pressurized air of blower outlet 24 directly to flow out.

A part 40 of the radially-outer surface 38 of nearer firing unit end 32, the pressurized air by flowing around transition duct 18 circumference is flowing to the cooling midway of firing unit 12.The cooling that this cooling raio inner radial surface 28 is stood is renderd a service low quite a lot of.A part 42 of nearer turbine end 36 radially-outer surfaces 38 is cooled off the poorest because the pressurized air of the process that circulates is considerably less here.Therefore, the significant degree of cooling descends to turbine end 36 gradually from firing unit end 32 on transition duct 18.Cooling problem on the part 42, because the hot combustion gas of flowing in transition duct 18 has strong turnover, thereby complicated more.Therefore, the effective heat transfer by convection of the height of hot combustion gas, effect on part 42.As a result, part 42 just becomes the hottest part in the transition duct 18, to being introduced the hot gas temperature of part 42 from firing unit 12, has formed effective restriction.Except maximum gas temperature was done to limit, the temperature imbalance on the transition duct 18 that causes also may constitute harmful heat expansion form, thereby may cause the premature damage of transition duct 18.

, temperature variation allows that also just the figure with desirable is opposite for then above-mentioned figure if can be transition duct 18.The part 34 and 42 of the nearly turbine end 36 of transition duct 18 just, the part 30 and 40 than nearly firing unit end 32 has lower robustness, thereby lower heat-resisting ability is arranged.At least, the decline of robustness, a part is being connected owing to back poppet 44 and part 42.Say that by ideal part 30 and 40 temperature should approximate the temperature of part 34 and 42, and allow than 34 and 42 high considerable temperature is arranged.Part 34 and 42 temperature should be near equating.

Before relating to impact technology of the present invention, understand disclosing in order to help, simply be discussed below now:

Referring to Fig. 2 plate 46 shown in it, its surface awaits cooling off with impacting.A striking plate 48 has spacing, give a farfetched interpretation on it some holes 50,52 and 54 with the surface of plate 46.Sealed end 56 bridging plate 46 and striking plate 48 form chamber 58.An outlet 60 in chamber 58 forms a unique opening, all by hole 50,52 and 54 air that spray, must discharge from this opening.

Can recognize that the pressure that crosses on the striking plate 48 falls, the effect that produces by the air jet of hole 50,52 and 54 is arranged.Hole 50 is owing to the most close closed end 56, the impact jet flow striking plate 46 of formation.The air that the hole is 50 li must flow to outlet 60, shown in airflow arrows 62 behind striking plate 46.Air in the impact jet flow that hole 52 forms must pass the cross flow that the air that sprays in hole 50 causes.Suppose that the amount that hole 50 and 52 sprays into the air in chamber 58 equates, so the amount of the air that forms doubles the amounts that spray separately in hole 50 in the merging air-flow of hole 50 and 52.As a result, the amount and the speed of the merging air-flow in 52 downstreams, hole are airflow arrows 62 indications, the amount of the horizontal air in arrival hole 52 and the twice of speed.The jet flow in hole 54 must be passed the cross flow that this merging amount forms, and just can project on the plate 46.The total amount of the air by 54 downstreams, hole has the speed of the air that is three times in 52 upstreams, hole.Because the speed of cross flow, along with downstream distance increases and increases, impact air-flow reach plate 46 the surface and suitably the ability of cooling also and then descend.

Now carrying what state is the embodiment of the present invention shown in Fig. 3 A, and this scheme can produce the temperature graph that needs by the specific cooling of situation on transition duct 18.Have spacing to center on an impact sleeve pipe 66 of transition duct 18, form airflow capacity 68 between the two, 36 places seal substantially at turbine end, and its firing unit 32 is opened wide.Impact some eyes 70 of giving a farfetched interpretation on the sleeve pipe 66, guide some impact jet flows to impact transition duct 18.As illustrating, because all useless impinging air all must flow to an outlet 72 of firing unit 32 at preamble.Its mass flow rate must increase regularly towards outlet 72.

The total pressure drop that impacts sleeve pipe is crossed in restriction, or the difference between the pressure of the pressure (compressor discharge pressure) of 22 li of restriction pumping chambers and airflow capacity 68 outlets 72 is very important.For example, this pressure being fallen what be limited in compressor discharge pressure perhaps is desirable below 2 percent.Lay down a definition as preamble, cross the needed pressure of speed of accumulation that the pressure in hole 70 falls and the cross flow that useless impinging air is accelerated to 68 li of airflow capacity, cause by impacting the total pressure drop of sleeve pipe 66.

As is generally known gas flow rate in the closed channel and conduit sectional area are inversely proportional to.Can notice the height of airflow capacity 68, increase gradually to firing unit end 32 from turbine end 36.This and airflow capacity 68 are on whole length, and the speed that air can reach when lasting lower height was arranged is compared, and tend to reduce near the airspeeies of outlet 72.So just, can utilize near the low height of the airflow capacity 68 the low turbine end of transverse mass flow velocity 36, and still can limit the speed of the cross flow of nearer outlet 72.

When impacting sleeve pipe 66 and transition duct 18 bigger spacing is arranged, just requiring to impact in the jet flow has bigger mass flow rate, and making to impact when jet flow is collided transition duct 18 has enough speed to cool off.Make the cross section that exports near the hole 70 72,, just can obtain the mass flow rate that increases, do not fall and need not increase the pressure that crosses impact sleeve pipe 66 greater than near the cross section the turbine end 36.Change the line-spacing in hole 70, and the pitch-row between row mesopore and the hole, just can make total air flow density that the hole battle array of macropore 70 produces greater than, be equal to or less than the total air flow density of the Kong Zhen in the orifice region.All these parameters are all shown in Figure 3.Just, the hole 70 of the first hole row near the impact sleeve pipe 66 the turbine end 36, there is little a lot of spacing in the hole 70 than near the metapore outlet 72 in capable.And, the line-spacing between the one or the two hole row at turbine end 36 places is also little a lot of than the line-spacing between near outlet latter two hole row 72.On intermediate portion, can see that also well-regulated pitch-row and line-spacing change.

The surface cool flexibility that any one parameter presents in the above parameter all helps to carry out distinguishing cooling by the requirement in the concrete application.When parameter being done control in pairs, or when doing all control, cross and impact sleeve pipe 66 low pressure drop of allowing is arranged, just can control the impact cooling of transition duct substantially fully.

Referring again to Fig. 3 A, the hole 70 on the air-flow sleeve pipe 26 ', can make not that part of firing unit air-flow that from impact sleeve pipe 66, passes through, before taking fire and useless impact air-flow merge.To hole 70 ' number, size and distribution elect, and air-flow is met the requirements, and cause the overall presure drop of needs for impacting sleeve pipe.Sealing 73 between air-flow sleeve pipe 26 and impact sleeve pipe 66, making between the two to have sizable off normal, and can prevent that air-flow from entering from their joint.If enter and just can cause the imbalance of airflow diversion between the two.Will be understood that since by hole 70 ' air-flow, vertical with useless impact air-flow, so need be according to impact air-flow, air-flow by each hole 70 ' ranks, and the summation of the air-flow in the annular airflow district between air-flow sleeve pipe 26 and the firing unit 12, increase a pressure and fall, by hole 70 ' air-flow accelerate to a new cross flow speed.

Another embodiment of the invention shown in Fig. 3 B and Fig. 3 A quite similar.Main difference is the structure shape of air-flow sleeve pipe 26, and the joint between the tapered inlet part 74 of the outlet end 32 of impact sleeve pipe 66 and air-flow sleeve pipe 26.Fig. 4 illustrates the amplification form of this joint, and outlet 72 wherein forms a ring runner 78 by tapered inlet part 74 corrals of air-flow sleeve pipe 26.Ring runner 78 has replaced hole 70 ' (Fig. 3 A), the air communication mistake that has the supply and demand of an area foot to want, and simultaneously for impacting the total pressure drop that sleeve pipe 66 causes to be needed.Because 22 pressure to ring runner 78 outlet fall from the pumping chamber, equal to cross the total pressure drop that impacts sleeve pipe 66, so the airspeed of discharging from ring runner 78 is high more a lot of than the airspeed of outlet 72.Because these two air-flows move closer in air-flow sleeve pipe 26, a favourable Momentum Transfer is just arranged to impacting in the sleeve pipe air-flow, near outlet 72, cause a low pressure area, the useless impact cooling air to airflow capacity 68 is discharged plays the scavenging effect.The clean effect of this scavenging effect is compared with the embodiment shown in Fig. 3 A, when the total pressure drop that passes through impact sleeve pipe 66 is identical, can reduce the total pressure drop between pumping chamber 22 and air-flow sleeve pipe 26 inside.In the present embodiment, in the firing unit of the parallel running more than ten, obtain uniform shunting and pressure and fall performance, require can do accurately control to the size of ring runner 78, similar to traditional or advanced heavy duty gas turbine engine.

Now referring to Fig. 5, a basic circular wall 80 is arranged in the back poppet 44, the whole circumference around transition duct 18 weld substantially, in the circular open 82 that impacts sleeve pipe 66, pass through, so form a cup-shaped volume 84 of cecum, the upper end communicates with pumping chamber 22, the lower end base closed.For disclosing fully and the effect of back poppet 44 of structure, at U. S. Patent the 4th, 422, be written into for No. 288, this paper quotes from for referencial use.Should be noted that transition duct 18 in this sectional drawing, outwardly-bent towards cup-shaped space 84.The technology that hereinafter discloses to transition duct 18 part coolings, a fabulous example is provided, illustrated at hot load, on all vicissitudinous surface of distance and tranverse air flow, the advantage and the flexibility of the impact cooling that employing can change, the part of this transition duct 18 is enclosed in the circular wall 80.

One has the impact of the wall 90 that extends upwardly and flat 92 to insert body 86, snugly fit in the cup-shaped space 84, flat 92 and the surface of transition duct 18 distance is arranged.The wall 90 that extends upwardly is preferably in the upper end portion a bead 94, does to install on the internal surface of circular wall 80 and uses.Bead 94 is method such as handy welding, is fixed on the circular wall 80.Last stretching an annular space is arranged between wall 90 and the circular wall 80, make and insert body 86 and wall 90, reach identical temperature, thereby reduce the thermal stress of this joint with before bead 94 is connected.Some holes 98 are arranged on flat 92, make the pressurized chamber in the pumping chamber 22 form the impact jet flow, to besieged surperficial 100 coolings in circular wall 80 of transition duct 18.

Since besieged surperficial 100 by circle walls 80 around, the mode that useless impinging air discharges from impact the space of inserting between the body 86 and besieged surperficial 100, must be different with the previously described mode that is used to impact cooling technology.Cooling off the amount of besieged surperficial 100 required cooling airs, is an insignificant ratio in the air total supply.Therefore, useless impinging air by film cooling hole 102, is entered the inside of transition duct 18, and needn't pay sizable cost, belong to feasible with the efficient that lowers the air-flow utilization.

Now the film cooling hole 102 that are positioned at below Fig. 7 flat 92 referring again to Fig. 6 and 7(dot), film cooling hole 102 is arranged to two staggered ranks 104 and 106, the position flat 92 with respect to transition duct 18 near the upstream edge of fuel gas flow.Shown in Figure 6 the most clear, film cooling hole 102 tilts in the gas flow direction of advance, thereby has promoted the air that passes through from transition duct 18, and the internal surface of transition duct 18 is done the film cooling.The localized heat load in this film cooling can the change strongly film cooling hole 102 downstreams.And, because the fuel gas flow of contiguous flat 92 upstream edges in film cooling hole 102 positions, therefore require all 98 impact cooling airs that enter from the hole, all flow to ranks 104 and 106, thereby can be as indicated above, generation can be impacted the strong cross flow that cools off with interfering near the air jet of row 104 and 106.Arrange besieged surperficial 100 to impact the another one challenge that cools off, in the quadrature sectional view of Fig. 5 and 6, can see the comparison of the shape of transition duct 18 in besieged surperficial 100.Just, in the analysing and observe of Fig. 5, besieged surperficial 100 mid point, more close more flat 92 than periphery, and in vertically the analysing and observe of Fig. 6 antithesis.Therefore, order is made complicated whole three parameters of specific cooling to besieged surperficial 100 and is all existed.Just, the variation that the localized heat load on besieged surperficial 100 has been cooled off owing to film, the validity of impacting jet flow is subjected to the influence of air cross flow, and be subjected to jet flow impact besieged surperficial 100 surperficial the time, the influence of the variation of the distance of passing through.

To specifically should be mentioned that Fig. 7 now.Nine row 108-124 are lined up in hole 98, and each row is vertical with the path of gas flow.There is relatively little diameter in three holes 98 of nearest every ranks 114,116,118 mid points.Why for a short time is result to the reaction of two factors: 1) this besieged zone of surperficial 100 has been subjected to the strong film cooling of film cooling hole 102,2) flat 92 relative near distance is arranged with besieged surperficial 100, as Fig. 5 by shown in the section of hole row 116.Be expert at three holes 98, the outside in 114,116 and 118 increase (see figure 5) successively with the increase of impacting the jet flow bulk range.

The moderate size is arranged and the shortest hole 98 of spacing in the hole row 108 and 124.This be to flat 92 and these between locational besieged surperficial 100 than short distance, and produce cross flow because there is not the upstream to impact jet flow, interfere the combined reaction of cooling air to besieged surperficial 100 projections or the like reason.Row 110 and 112 has that size is big, the hole 98 of spacing broad, and compensation is impacted the cross flow of jet flow and the increase (see figure 6) of distance from the upstream.

According to above understanding, the present invention can be in thermal force, on the surface that three parameter tools such as distance and air cross flow are deposited, in the separate ranges of its domain of dependence, does specific cooling impacting the jet flow cooling.In the embodiment with impact sleeve pipe 66 cooled transition ducts 18 of the present invention, specially strengthen the distance between transition duct 18 and the impact sleeve pipe 66, and pass through the increasing of the diameter complementary range in increase hole 70, with the speed of control air cross flow.The spacing of large diameter hole 70 is increased the density of mass flux of control air.In besieged surperficial 100 the embodiment in cooling back poppet 44 of the present invention, distance is generally by the design decision of transition duct 18.Vicissitudinous distance is regulated by the diameter and the spacing of suitable control hole 98.And the handling problem of useless impinging air is gone to solve by utilizing useless impinging air to do the film cooling, and is further changed the diameter and the spacing in hole 98, compensates the sum of any pressure drop variations on besieged surperficial 100.

Though desirable embodiment of the present invention is described with reference to accompanying drawing, but should understand the present invention does not limit with these specific embodiments, allly be good at this skill field person, can make variations and modifications to embodiment, and not exceeding scope of the present invention or spirit, scope and spirit of the present invention are pressed in claims behind the literary composition and are determined.

Claims (9)

1, a kind of impingement cooled transition duct that is used for combustion gas turbine, wherein transition duct is being connected in the entrance point of the discharge end of firing chamber and combustion gas turbine, one is impacted cooling collar and is fit to around this transition duct, and separate a radial distance, thereby form an airflow capacity betwixt, impact cooling collar a firing chamber end and a turbine end are arranged, the size of the firing chamber end of impact sleeve pipe is greater than the firing chamber end of transition duct, form an outlet at the firing chamber end that impacts sleeve pipe, the size of impacting the turbine end of sleeve pipe is fit to sealing and is connected on the transition duct, impact and form some holes on the cooling collar, each Kong Youyi area and the spacing that adjacent hole is separated, it is characterized in that: described at least distance, in area and the spacing one of them changes at described impact sleeve pipe, thus the cooling of control transition duct.

2,, be characterized as described distance and increase to this firing chamber end from this turbine end as the impingement cooled transition duct in the claim 1.

3,, be characterized as described area and increase to this firing chamber end from this turbine end as the impingement cooled transition duct in the claim 1.

4,, be characterized as described spacing and increase to this firing chamber end from this turbine end as the impingement cooled transition duct in the claim 3.

5, as the impingement cooled transition duct in the claim 1, being characterized as described spacing, distance and area is the cooling of repairing described transition duct inconsistently.

6, as the impingement cooled transition duct in the claim 1, being characterized as in the turbine end of transition duct settles an afterbody with continuous wall to support, one is impacted the insertion body, comprise a wall portion and the planar base surface of compact configuration in afterbody supports continuous wall, distance of planar base surface and transition duct spaced surface is provided with some holes on planar base surface, the guiding impact air-flow enters the transition duct surface, some film cooling hole are arranged on transition duct, make the impact cooling air become hot air flow.

7, as the impingement cooled transition duct in the claim 6, be characterized as, in the area in hole on the planar base surface and spacing according to the variable in distance between the surface of planar base surface and transition duct.

8, as the impingement cooled transition duct in the claim 1, be characterized as, air-flow sleeve pipe around the firing chamber, this air-flow sleeve pipe has a tapered inlet part, put up the outlet of impacting sleeve pipe, limit an annular airflow path, make the interior flow velocity of annular airflow path surpass the flow velocity of useless impact air-flow with enough areas.

9, as the impingement cooled transition duct in the claim 1, be characterized as, an air-flow sleeve pipe that also almost extends jointly around the firing chamber, lip ring between air-flow sleeve pipe and impact cooling collar, some holes on the air-flow sleeve pipe, the part of the pressurized gas of obstructed overbump cooling collar combines with useless impact air-flow.

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