A method and apparatus for burning fuel with air


F23D23 - Assemblies of two or more burners (gas burners with provision for a retention flame F23D0014260000; arrangement or mounting of burners F23C0005000000; for industrial furnaces F27)

 

(57) Abstract:

Method and device for burning fuel with air intended for use in the energy sector. In the process in the combustion chamber through one intake hole serves the air, and after a few burners - fuel. Each burner has its delay time corresponding to the time interval after which the acoustic pulse in the combustion chamber produces a thermal pulse combustion supplied through the fuel burner. When this flow of fuel through the burner control so that the delay time of burners significantly different from each other. The invention is applied to the combustion chamber of a gas turbine and provides reliable suppression of combustion oscillations. 2 C. and 15 C.p. f-crystals, 3 ill.

The invention relates to a method for burning fuel with air in the combustion chamber, to which at least one intake hole serves the air, and after a few burners - fuel, and each burner has its delay time corresponding to the time interval after which the acoustic pulse in the combustion chamber generates a heat pulse during combustion the air.

Such method and apparatus is described in WO 93/10401 A1.

The invention relates in particular to a method and apparatus of the above kind for use in a gas turbine, and gas turbine is a block from the compressor for air, combustion appliances, including at least one combustion chamber for burning fuel in the air with the flue gases, and a turbine in the proper sense of this word for the expansion of the flue gases. The turbine may be composite, i.e., to include several cascaded sections; the same applies to the compressor. The compressor is made in the form of a turbocharger. In practice, the turbine drives the compressor.

The invention proceeds from a task damping or preventing acoustic oscillations in the combustion chamber created in the combustion process and is known as "vibrations burning".

In many combustion chambers, namely as in combustion chambers of gas turbines and combustion furnaces boilers, industrial furnaces, or other facilities, under certain conditions, clearly caused by the relevant thermodynamic operating parameters such as the ratio of the excess vozduhoplavateli heat of combustion and the static pressure in the combustion chamber and/or included before and after her installation parts. These fluctuations are expressed in the fact that in the combustion chamber produces acoustic self-oscillations. These acoustic vibrations cause in addition to increased noise in the environment of the installation concerned reinforced mechanical and thermal loads on the combustion chamber and other parts of the installation, which in a short time, it can lead to complete or partial failure.

The increasing use of burners with pre-mix in the respective combustion chambers as growth requirements, if possible, non-toxic combustion causes due to the higher density of the reaction, owing to the burner with pre-mixing, ignition, more dependent on the chemical composition intended for the combustion of the mixture than in the diffusion burner, as well as smaller compared to the diffusion burner convective time delay formed inside the flame increased tendency to the formation of combustion oscillations.

The combustion oscillation is based mainly on the interaction between the flow coming out of the burner used participants ' reactions and energy transfer during combustion, and engagement in combination with the acoustic realnoe acoustic oscillation. This is made of burners, including carts, the flame and the combustion chamber or together with the acoustic vibrating system forms a closed working circuit. The energy required to create and maintain the acoustic vibrations produced during the combustion.

Acoustic conditions in the combustion chamber, including the attached system, explained in detail in the book by A. A. Putman "Combustion-Driven-Oszillations in Industry", American Elsevier Publishing Company, Inc., New York 1971, page 2. You should also refer to thesis "rimentelle und theoretische Untersuchungen der Entste-hungsmechanismen selbsterregter Druckschwingungen in technischen Vormisch-Verbrennungssystemen", Karlsruhe, 1992, pages 4 and 5. Presented and explained known as the "Rayleigh criterion" a condition that must be observed, so that could be a stable oscillation burning.

From the Rayleigh criterion is also displayed criterion, which sets the connection duration of the period of the acoustic wave, for which the possibility of its occurrence, with the "delay time", essentially characterizing the burner and its operation. This time delay is the time interval after which the acoustic pulse in the combustion chamber that is attached to the burner combustion chamber of stable oscillations induced by the burner thermal fluctuations, i.e., periodic changes in metabolism caused when the burner is burning, the delay time corresponds to the phase difference between the acoustic and thermal fluctuations. Here it should refer to thesis, pages 26-29, and article J. Herrmann, P. Zangl, S. Gleis, D. Vortmeyer "Untersuchung der Anregungsmechnismen selbsterregter Verbren-nungsschwingungen an einem Verbrennunssystem VDI Berichte Nr. 1193 (1995), pages 251-260.

The delay time of the burner in the combustion chamber consists of various components related to individual system components of the burner, combustion chamber and flame. Terms that are related to the burner and the combustion chamber, determined mainly by the geometry of the burner and the combustion chamber; the term relating to the flame, is determined mainly by the properties of combustion. The very term can be further decomposed into "convective time delay", which characterizes the time for transportation of participants ' reactions to the flame front, where the combustion, "heating time", which indicates the time for heating the participants reactions to the ignition temperature, and reaction-kinetic delay time, which is determined by the process of combustion. Typically, the convective time delay is of based either on the use of more or less empirically passive acoustic means, such as inductors, resonators and/or heat sinks (see the above book, pp. 156-175), or on the fuel supply to the active modulation with the aim of separating the released energy from acoustic oscillations in the combustion chamber. This measure is called "active control of instability"; for explanations, see S. Gleis, D. Vortmeyer "Die 'als aktive Untersuchungsmethode selbsterregte VDI Berichte Nr. 756 (1989), pp. 645-656. In DE 4241729 Al described the actuator, through which a pressurized stream of liquid impart oscillation of the mass flow or pressure. The actuator is proposed for use for active control of combustion instabilities in burners for liquid fuel, as well as in devices for spraying liquids.

Conventional passive measures suppression of combustion oscillations aimed at stabilizing the operation of the plant due to displacement of the acoustic properties of the parts of the system so that combustion oscillations have occurred around the desired operating range. These measures require funds, which in each case need to be brought into compliance with this setting and always carry the danger of what is known unstable operating point will, however, stable, however, in other work the combustion chambers. Here in the direction of flow in front of the combustion chamber there are several burners, and other burners are located in the flow direction are offset in relation to each other at a given distance. This specified distance is selected so that during operation of the burners extending in the direction of flow fluctuations in temperature adjacent burners are oppositely directed. Thus, in cross-section relative to the flow direction of the combustion zone with positive and negative deviations from the average temperatures are near, and there is a mixing of these zones in the direction of flow and, thereby, raises the temperature uniformity. This should prevent oscillation burning, caused by temperature fluctuations, and thus, on the basis of different densities also pressure fluctuations.

Active measures for the suppression of combustion oscillations can be implemented in industrial installations only with high costs, in particular when it is necessary to use a liquid fuel, and in addition, they are prone to failure and require maintenance. In addition, they only lead to a damping of the respectively existing instabilities and their effectiveness is severely limited by the decision the object of the invention is the development of new passive measures in the combustion chamber with multiple burners, suitable for reliable suppression of combustion oscillations. Measures should be applicable both for liquid and gaseous fuels, regardless of hardware and functional characteristics of the combustion chamber. Should not be used moving parts or other active components. The invention shall disclose as a corresponding method and a corresponding device.

In relation to the way to solve this task according to the invention, a method for burning fuel with air in the combustion chamber, to which at least one intake hole serves the air, and after a few burners - fuel, and each burner has its delay time corresponding to the time interval after which the acoustic pulse in the combustion chamber produces a thermal pulse combustion supplied through the fuel burner, and the fuel through the burner and supply air through the intake opening is controlled so that the delay time of burners significantly different from each other.

The invention derives from the fact that in the combustion chamber, usually used in a gas turbine and containing, as a rule, many of the same th is La only one burner there are thermal fluctuations in the interaction with acoustic vibrations, this one burner also excites vibrations in any other burner of the combustion chamber. This effect is expressed, for example, that in the combustion chamber with multiple identical burners are correspondingly sharp transitions between work conditions with fluctuations burning or without them. Since the occurring oscillations burning always come from several burners, such fluctuations in the combustion are also very high amplitude.

In contrast, the invention provides for the use of burners with different acoustic properties, i.e., first of all, different time delays. Because of this burner cannot interact with each other, and, in addition, you can always use a damping effect spring each time from the stable working of the burner.

When each burner is appropriate intake hole through which the air supplied to the corresponding flow in the combustion chamber, the method mainly carried out so that the respective threads in burners differ significantly from each other. Because of this guaranteed reliable difference from each other thermodynamic conditions characterizing dannoun implementing the method, and each burner is appropriate intake hole through which the air supplied to the corresponding flow in the combustion chamber, characterized in that the burner is made between basically the same and on each burner, in addition to the respective intake openings corresponding to the flow drossellied, so that all relevant flows are significantly different from each other. Alternatively, the corresponding flow drossellied on each intake hole; it may be desirable to make the flow of certain desired properties, such as its homogenization. These options allow implementation to use burner made between basically the same, and through a simple and cheap additional measures provide the necessary difference of the delay time.

Another variant of the method for the case when each burner is appropriate intake hole through which the air supplied to the corresponding flow in the combustion chamber, and the corresponding flows are geometrically similar, differs in that the burner geometrically similar, but have different values of the e, this is to allow for the burners of one form and for producing different burners to be only the scale of various sizes. The difference of the delay time is saved, since the delay time of one of the burner is determined not only by its geometry and is thus invariant to the scale.

All described embodiments of the method can be improved in such a way that to each burner fuel serves with respect given to all burners ratio between the speed of the supplied fuel and speed supplied through the corresponding intake opening of the air. This option is of particular interest because it allows to exploit each burner to achieve a desired, generally from the combustion of heating power in an optimal way in reducing always undesirable formation of nitrogen oxides. This option, however, requires correspondingly accelerated fuel.

Alternatively, can also be provided for the fuel supply to each burner set for all burners speed. This means, however, that a separate burner will operate imperfectly in the wearing ease fuel.

Special is the way it has when used in combination with the combustion chamber, is arranged to rezoniruya acoustic vibrations with a certain period, with a corresponding delay time of each of the burner lies between integer multiple of the length of the period minus a quarter of the length of the period and an integer multiple of the duration of the period plus a quarter of the length of the period. This corresponds to the compliance of the extracted Herrmann and others, as well as Off from the Rayleigh criterion criterion between the time delay and duration of the considered acoustic oscillations. The notion of "integer multiple" includes also zero. It is clear that the delay time is, by definition, cannot take negative values. A sign related to the fact that the combustion chamber is arranged to rezoniruya acoustic oscillations should not be taken as restrictive in the sense that defining this resonance is only one combustion chamber; it is clear that the combustion chamber, as a rule, is part of a more or less complex overall acoustic system, and resonance with all major parameters opredelennosti, each burner fuel is mixed with air before it will burn in the combustion chamber. Under this option is used, thereby, respectively, of the famous "burning of pre-mix". Burning with preliminary mixing is of particular interest because it occurs at lower temperatures than caused by simple means of diffusion combustion, and therefore significantly less than the diffusion combustion, prone to the formation of nitrogen oxides. In this regard, it is important that the invention also creates a compromise to the above-mentioned thermodynamic-acoustic problems burning with pre-mix.

Way, in any form especially suitable for use in a gas turbine, and prepare air in the compressor and the combustion gases generated in the combustion chamber when the combustion air fed to the turbine.

For solving the problem related to the device proposed according to the invention a device for burning fuel with air containing a combustion chamber, in which combust fuel with air, at least one intake opening for air supply into the combustion chamber, multiple burners for supplying Topley is after which the acoustic pulse in the combustion chamber produces a thermal pulse combustion supplied through the fuel burner, and toplivoprovod for supplying fuel to the burners, characterized in that the delay time of burners differ significantly among themselves.

The main advantages of this device are derived from the advantages of the method according to the invention and variants of its implementation. Method and variations in its implementation require, under certain circumstances, certain elements of the device, which should be considered as signs embodiment of the device according to the invention. The same applies to the features of the process that arose from the device and options for its implementation and which should also be considered as signs of variants of the method.

A preferred improvement of the invention differs in that the burner geometrically different from each other.

Alternatively, the burner device is geometrically identical to each other, and toplivoprovod made for fuel supply to the burners with the corresponding velocities that are significantly different from each other.

Another alternative is characterized by the fact that each burner is appropriate intake hole and on each burner, but one or each burner of pradosha. This choke can be performed, for example, installed in front of the burner valve.

Especially preferred is the improvement of devices in that the combustion chamber resonates acoustic wave with a definite period and that each burner corresponding to the delay time lies between integer multiple of the length of the period minus a quarter of the length of the period and an integer multiple of the duration of the period plus a quarter of the length of the period. This run corresponds to the already described embodiment of the method, and all of the above reasoning similarly refer to the version of the execution device.

Especially preferred is the use of the device in a gas turbine, the combustion chamber is located between the compressor and the turbine.

In relation to the location of the several burners in the combustion chamber should be noted that it is preferable, where possible, their asymmetric localization. How asymmetric location might look like in each case and what criteria should be assessed "sufficient asymmetry", is available in each con is that you should pay special attention boils down to the fact that the acoustic oscillation, usually has a more or less symmetrical arrangement of standing acoustic waves in the entire oscillatory system. As an example, reference should be made to observe on the annular combustion chamber of a combustion oscillation, characterized by acoustic waves that flowed in a closed form annular combustor. The wavelength of acoustic oscillations corresponded to the half of the average circumference of the annular combustion chamber. To suppress such oscillations would be preferable to avoid when burners dvuhjadernyh or chetyrehkolenny symmetries.

The invention does not require that the combustion chamber was not two burners with the same properties; the purpose of the invention can meet the combustion chamber, to which of several types of burners attached several burners of each type. In this regard, the gas turbine with two bunker combustion chambers of conventional type, each of which contained six identical burners for combustion of fuel oil, when working below the 80% required for the calculation of the nominal load was observed acoustic oscillations with amplitudes of 100 mbar. These Akusticheskie modified burner. Modified burners were made so that at rated load, they received approximately 8% less fuel than unmodified burner. Modified burner was used so that they made between a single unmodified burner. A modified implementation of burners allowed to operate the gas turbine up to 100% of its rated power without generating acoustic vibrations noticeable amount.

Implementation examples of the invention are explained using the drawing. Drawing is a partially schematic, and it should not be seen as a reflection of specifically made plants or their components. To complement the above with drawing instructions, you should refer to the explanation really tested, said publication relating to prior art, and knowledge of a specialist with experience in this area. In the drawing depict:

- Fig.1 a gas turbine and a device for burning fuel with air;

- Fig.2 a top view of the combustion chamber with multiple burners;

- Fig.3 is a schematic cross-section of the combustion chamber with multiple burners.

In the drawing corresponding to each other, the components denoted by the EOS 1, the turbine 2, the shaft 3, the duct 4, the combustion chamber 5, the pipe 13 for the flue gases. Turbine 2 will cause the compressor 1 through the shaft 3. From the compressor 1, the compressed air goes through the air duct 4 to the combustion chamber 5 and enters it through the intake holes 6, each of which relates to a burner 7, and each burner 7 is located in the rear wall 8 of the combustion chamber 5. For fuel supply to the burners 7 is provided toplivoprovod containing tank 9, pump 10 and the fuel supply line 11. The burner 7 is supplied with fuel from a tank 9 by a pump 10 through a fuel pipe 11, branching at the burner 7. This fuel is burned in the chamber 5 combustion supplied through duct 4 air.

Camera 5 combustion is capable of acoustic oscillations design and may, if necessary, be considered as an integral part of all capable of acoustic oscillations of a system that includes, for example, the camera 5 combustion leading from it to the turbine 2 pipe 13 for flue gases, and, if necessary, the duct 4 and the fuel supply line 11. Acoustic oscillations in the chamber 5 of the combustion, which varies by itself or as an integral part of the entire system, can be instituted and poderia can become so strong, what camera 5 combustion and other parts of the gas turbine can be damaged.

To avoid such fluctuations in the combustion and, in particular, to exclude, to multiple burners 7 interacted arouse such fluctuation of combustion, the burner 7 is made between a different. This leads to the fact that not all burners 7 have the same basic properties and, in particular, characterizing the combustion process, the time delay different from each other. Thus, the implementation according to Fig.1, in any case, exclude the possibility that the burner 7 will work together to initiate oscillation of burning.

Guidance on the preferred principle of operation of the burners 7 are already given; all these instructions are of interest to is shown in Fig.1 of the exemplary embodiment. In particular, it is possible to distribute the fuel in the burner 1 in accordance with certain preferred preset values; thus it is possible, in particular, to act in such a way that each burner 7 worked so quickly fed through its respective intake port 6 air was specified for all burners 7 ratio with the speed being fed through its respective fuel nozzle 12. Tekojoja a lower level.

The burner 7 in Fig.1 is depicted as a so-called diffusion burners, because they inject the fuel directly into the chamber 5 of the combustion. This fuel can be mixed with the supplied air only in the chamber 5 of the combustion, which, from experience, is due to the diffusion. Diffusion burners have a simple construction and can be operated relatively simple way, but in the formation of nitrogen oxides they are inferior to more complex burners pre-mix, illustrated by means of Fig.2.

In Fig.2 depicts a top view of the rear wall 8 of the combustion chamber 5 when viewed in the direction in which air flows into the chamber 5 of the combustion. In the rear wall 8 has a built five burners 7 are made mostly equally among themselves. Each burner 7 has a certain number avirama blades 14, which gives the turbulence passing through them the air. This turbulence has the advantage for the combustion and homogeneous mixing of fuel with air. In the swirler vanes 14 are provided nozzles 12, from which the fuel gets into the air, before he goes on camera 5 combustion and fuel can ignite. In accordance with that depicted on the more complicated the design, than the diffusion burner, but in the formation of nitrogen oxides have compared them with significant advantages. Burner with pre-mix delivers a mixture of fuel and air with a certain composition on combustion, allowing significantly more fine-grained control of combustion than the diffusion burner, where the mixing process of fuel and air is almost unmanageable. Combustion occurs in the burner pre-mix is also at a significantly lower maximum temperatures than the diffusion burner, which is preferable to prevent the formation of oxides of nitrogen. Each burner 7, the hub 15 is surrounded by the blades 14 and hub 15 can be used to supply fuel to the injectors 12.

In the example of execution according to Fig.2 before four of the five burners equipped with dampers in the form of the throttle 16, each of which partially covers the swirler vanes 14 and acts thus as a throttle for entering the burner 7 of the air flow. Due to this, the basic operating parameters of all of the burners 7 are different from each other, which eliminates the interaction of the burners 7 for excitation of oscillations of the combustion chamber 5 combustion. Reasoning concerning the PWG.3 shows a longitudinal section of the combustion chamber 5 with its rear wall 8 and two-burner 7. The burner 7 is also made in the form of burners pre-mix. Each burner 7 includes three nozzles 12 for the fuel pump, mounted on the hub 15. Two injectors fuel gets between the swirler vanes 14, with the result that he mixes with the flowing air. One nozzle 12 is facing directly into the combustion chamber 5 and forms a so-called "pilot flame in which combustion occurs-type diffusion burner; this is a pilot flame is used to stabilize the combustion mixture of air and fuel formed between the swirler vanes 14 and which usually has an excess of oxygen. This allows you to regulate the production of heat by the burner 7 in wide limits.

Both burners pre-mix geometrically similar, i.e., they differ from each other only in size, but not the proportions. Also this implies the difference of the respective operating parameters used to exclude the interaction of these burners 7 for excitation of oscillations of the combustion chamber 5 combustion.

1. A method of burning fuel with air in the chamber (5) combustion, to which at least one intake opening (6) serves the air, and through a number of the after which the acoustic pulse in the chamber (5) combustion produces heat pulse combustion supplied through the burner (7) fuel characterized in that the supply of fuel through the burner (7) and the flow of air through the intake opening (6) is adjusted so that the delay time of burners (7) is significantly different from each other.

2. The method according to p. 1, wherein a) to the burner (7) is the corresponding intake opening (6) through which the air supplied to the corresponding flow in the chamber (5) combustion, and (b) corresponding threads in burners (7) are significantly different from each other.

3. The method according to p. 1, wherein a) of the burner (7) is made of honey basically the same; b) to each burner (7) is the corresponding intake opening (6) through which the air supplied to the corresponding flow in the chamber (5) combustion, and C) on each burner (7), in addition to the respective intake openings (6), the corresponding flow drossellied, so that all relevant flows are significantly different from each other.

4. The method according to p. 1, wherein a) of the burner (7) is made of honey basically the same; b) to each burner (7) is the corresponding intake opening (6) through which the air supplied to the corresponding flow in the chamber (5) combustion, and b) for each intake opening (6) sooto p. 1, in which (a) the burner (7) geometrically similar, but have different value; b) for each burner (7) is the corresponding intake opening (6) through which the air supplied to the corresponding flow into the chamber (5) combustion, and the corresponding flows are geometrically similar.

6. The method according to one of paragraphs. 1-5, in which in each burner (7) fuel serves with respect given to all burners ratio between the speed of the supplied fuel and speed supplied through the corresponding intake opening (6) of the air.

7. The method according to one of paragraphs. 1-5, in which each burner (7) fuel serves to set for all burners (7) speed.

8. The method according to one of the preceding paragraphs, wherein the chamber (5) combustion is made with rezoniruya acoustic vibrations with a certain period and for each burner (7) corresponding to the delay time lies between integer multiple of the length of the period minus a quarter of the length of the period and an integer multiple of the duration of the period plus a quarter of the length of the period.

9. The method according to one of the preceding paragraphs, when kotorov one of the preceding paragraphs, when the air is prepared in the compressor (1), and the flue gases generated in the chamber (5) combustion fuel combustion in the air fed to the turbine (2).

11. Device for burning fuel with air, containing (a) camera (5) combustion for burning fuel with air; b) at least one intake opening (6) for feeding air into the chamber (5) combustion; b) multiple burners (7) for feeding fuel into the chamber (5) combustion, with each burner (7) is the time delay corresponding to the time interval after which the acoustic pulse in the chamber (5) combustion can generate a heat pulse combustion supplied through the burner (7) fuel, and g) toplivoprovod fuel to burners (7), characterized in that the delay time of burners (7) is significantly different from each other.

12. The device according to p. 11, in which the burner (7) is geometrically different from each other.

13. The device according to p. 11, in which the burner (7) geometrically identical and toplivoprovod made for fuel supply to the burners (7) with the corresponding velocities that are significantly different from each other.

14. Device according to one PP. 11-13, in which each burned the orifice (16) for throttling passing through the corresponding intake opening (6) of the air flow.

15. Device according to one of paragraphs. 11-13, in which each burner (7) is the corresponding intake opening (6) and on each burner (7), a throttle (16) for throttling passing through the corresponding intake opening (6) of the air flow.

16. Device according to one of paragraphs. 11-15, in which the camera (5) combustion is made with rezoniruya acoustic vibrations with a certain period and for each burner (7) corresponding to the delay time lies between integer multiple of the length of the period minus a quarter of the length of the period and an integer multiple of the duration of the period plus a quarter of the length of the period.

17. Device according to one of paragraphs. 11-16, in which the camera (5) combustion is a gas turbine between the compressor (1) and the turbine (2).

 

Same patents:

The invention relates to a power system and can be used in installations of heating water for heating and/or hot water supply of buildings and structures in a decentralized manner

The invention relates to a device for the surface treatment of the flame blanks and can be used in the manufacture of quartz blanks, premature extraction of the optical fiber

FIELD: recycling.

SUBSTANCE: device has body with cone and side tank, moving lid, connected to drive by rod, compacting inserts are mounted above the lid in area of its end positions in cone and side tank, cover of cone and side tank are made removable, on the walls of side tank guides are placed, below cover of cone on inner surface of compacting insert resilient scraper is placed in form of profiled plate, length of which is equal to width of lid along the side adjacent to side tank, on the body of cone pressing stops are placed, and on lower portion of lid wedge-shaped pieces are placed and an eye, in which vertical groove is made, in the groove with possible free movement a finger of rod is placed, rod input assembly is pressurized. Lid is made hollow and contains a system for feeding coolant, coolant influx assembly is pressurized. Coolant feeding system is made in form of coaxial pipeline, evenly positioned in hollow of lid.

EFFECT: higher reliability.

2 cl, 1 dwg

FIELD: power engineering.

SUBSTANCE: valve comprises rotatable housing provided with passage, outer unmovable ring seal of the housing, ring seal between the rotatable housing and outer unmovable ring seal of the housing that has bore made for permitting gas to flow to the passage or from the passage. The ring seal is movable with respect to the outer ring seal of the housing. The passage and the bore are made for permitting receiving the compressed gas to provide continuous sealing between the outer ring seal of the housing and ring seal when the housing rotates. The valve is additionally provided with means for permitting gas to flow through the radial passage and between the ring seal and outer unmovable ring seal of the housing and setting ring connected with the rotatable housing and locking ring that is mounted at a distance from the setting ring and connected with the rotatable housing. The ring seal is interposed between the setting ring and locking ring.

EFFECT: simplified structure and enhanced efficiency.

16 cl, 30 dwg

Up!