SK279552B6 - Method for sealing a rotor shaft with respect to a housing of a turbo-engine and a turbo-engine for processing thereof - Google Patents

Abstract

There is disclosed a method for sealing a rotor shaft (2) with respect to a housing (1) of a turbo-engine (15) with a dry gas sealing system (3) between the housing (1) and the rotor shaft (2). A purified transported gas is fed into the dry gas sealing system (3) from the inside of the housing (1), and, a seal gas is fed into the dry gas sealing system (3) from the outside of the housing (1) thus transporting the gas mixture of a leaked gas and seal gas. The gas mixture of the sealed and leaked gas existing in front of the gas sealing system (3) on the external housing side (1) is drawn and fed on the side of the air-suction into a gas engine (19, 20). The turbo engine (15) has at least one gas engine (19, 20) containing discharging piping (35), intake piping (21) and suction piping (24). The latter is connected to the second outlet (14) of the gas mixture of the leaked and seal gas out of the turbo-engine (15).

Description

A method of sealing a rotor shaft (2) with respect to a housing (1) of a turbo-aggregate (15) with a dry gas sealing system (3) between the rotor shaft (2) and the housing (1), (1) feeds the cleaned transported gas from the outside of the housing (1) and feeds the escaped transported gas mixture with the feed gas. The gas-gas escaping gas mixture occurring in the gas sealing system (3) on the outside of the housing (1) is exhausted and introduced on the air intake side into the gas engine (19, 20) fed by the otherwise transported gas. The turbo-generator (15) comprises at least one gas engine (19, 20) with a flue gas exhaust pipe (35), a combustion gas supply pipe (21) and a combustion air intake pipe (24) connected to the expensive outlet (14) mixtures of leaking transported gas with turbo aggregate tail gas (15).

Technical field

BACKGROUND OF THE INVENTION The present invention relates to a method for sealing a rotor shaft with respect to a housing of a turbo-aggregate operating in a transported gas conduit, with a dry gas sealing system between the rotor shaft and the housing, introducing into the gas sealing system. The transported gas is cleaned from the housing and from the outside of the housing, the gas is withdrawn, and a mixture of escaped transported gas and the leaking gas present in the gas sealing system on the outside of the housing is removed.

The invention further relates to a turbo aggregate for carrying out this method, with at least one turbomachine operating in a transported gas conduit, comprising a housing in which the rotor shaft is housed, a dry gas sealing system positioned between it and the housing in front of the outer and inner at least one partition wall is provided upstream of the housing, the first space between the partition wall on the inside of the housing and the gas sealing system being provided with a gas supply, while the third space between the partition wall on the outside of the housing and the gas sealing system is provided with a second mixture outlet escaping transported gas with feed gas.

BACKGROUND OF THE INVENTION

Dry gas seal systems have been proven to work on both gas turbochargers and turboexpanders. The preparation of the feed medium required on the inside of the housing does not pose any problems. Usually, the transported gas, which is available under a pressure of sufficient pressure, is branched off and cleaned and introduced into the gas sealing system.

The disadvantage is that on the outside of the housing of the gas sealing system there is a leaking transported gas which must be removed. The amount of gas transported depends on the pressure of the transported gas and the speed of the turbomachine. The transported gas leak occurs even when the turbomachine is stationary. Usually, it is unacceptable that the escaping transported gas is discharged into the space where the turbomachine is installed. Therefore, it is discharged together with the gas above the roof to the surrounding atmosphere. The escaping transported gas is thus lost.

SUMMARY OF THE INVENTION It is an object of the invention to expediently utilize transported gas that escapes from dry gas sealing systems.

SUMMARY OF THE INVENTION

The problem is solved and the drawbacks of the known methods of sealing the rotor shaft with respect to the housing are largely eliminated by the method of sealing the rotor shaft with respect to the housing of the turbo-aggregate according to the invention, which consists in the gas mixture escaping with gas. outside the housing, it is sucked out and introduced on the air intake side into the gas engine powered by the otherwise transported gas.

The gas engine may be used to produce electrical power to a device that may be, for example, a compressor station, or to drive other auxiliary units. The leaked gas mixture with the dead gas from the dry gas sealing system arrives in the combustion chamber of the gas engine, where at least the leaked transported gas is burned, which is thus energetically utilized by the gas engine. The fluctuation of the amount of gas escaping, in particular in relation to the engine control, is compensated by withdrawing from the gas conveying line through the inlet preheater stage to compensate for the Joule-Thompson effect and the pressure regulator. If a gas turbine is operated in the station, the internal combustion engine can be supplied from its combustion gas supply.

Advantageously, air is supplied as the obstruction gas on the outside of the housing. The ratio of the escaped gas to the tail gas is preferably adjusted such that the inlet gas-air mixture is not ignitable in the turbomachine region. Said adjustment may further be selected such that with this mixture all the combustion air required for the gas engine is supplied to the gas engine. The ignitability of the mixture in the gas engine is ensured by withdrawing the gas from the gas transport pipe.

Particularly advantageous proportions are achieved in that the gas engine sucks in a mixture of the escaping transported gas with air occurring on the outside of the housing, possibly via a suction fan. In this way, a further substantial advantage is achieved in that the return air no longer has to be supplied as compressed air but is sucked in by a gas engine. The intake air can also be used to cool the bearing located on the outside of the housing. This solution is based on reliably avoiding oil contamination of the gas sealing system, for example by using magnetic bearings. Usually it is sufficient without a suction fan. If the pressure drop across the bearing is too great, additional air may be drawn in through the holes in the housing. Said apertures are then formed between the gas sealing system and the bearing. Only if the pressure loss on the suction side of the gas engine is still high, the suction fan, typically an electrically driven suction fan, is used on the air intake side.

Another advantageous variant of the method according to the invention is that in the two-stage embodiment of the gas sealing system, the gas present between the two sealing stages is transported as a combustion gas to the gas engine. The pressure of the gas to be transported between the two sealing stages is adjusted in such a way that it corresponds to the pressure in the combustion gas line to the gas engine. The mixture of escaping transported gas with the return air between the second sealing stage and the outside of the housing is introduced as combustion air into the gas engine.

It is preferred that flue gases from the gas engine are introduced from the outside of the housing into the gas sealing system. These flue gases have the character of an inert gas at = 1-regulation and can also be used to reliably shield the gas sealing system from the oil-lubricated bearing located on the outside of the housing. Combustion gases with the air can form a gas which is supplied to the outside of the housing. In addition, it is also possible to use only the flue gas as the feed gas. This solution has the advantage that no flammable mixture can be produced on the outside of the housing, even in the event of a failure, when a large amount of gas is leaking out when the gas sealing system fails.

The invention furthermore relates to a turbo-generator with at least one turbomachine operating in a transported gas conduit comprising a housing in which the rotor shaft is mounted, a dry gas sealing system is positioned between it and the housing, upstream of which is at least upstream and downstream of the housing. one partition, wherein the first space between the first partition wall on the inside of the housing and the gas sealing system is provided with an inlet for transported gas, while the third space between the partition wall on the outside of the housing and the gas sealing system is equipped with a second outlet of the escaping gas mixture a gas according to the invention, characterized in that the turbo aggregate comprises at least one gas engine with a flue gas exhaust pipe, a combustion gas inlet pipe and a combustion air intake pipe, the combustion air intake pipe being at least one gas engine; connected to the second outlet of the gas escaping gas mixture from the turbo engine. A suction compressor is provided between the gas engine and the second outlet of the mixture of escaping transported gas with the turbo gas. The leaking gas from the dry gas sealing system is therefore used for energy in a gas engine, possibly supported by a suction compressor, at the same time taking over the transport of the cooling and the gas. The feed gas is preferably made up of air which at least partially covers the consumption of combustion air in the gas engine.

Another advantageous embodiment of the turbo-aggregate according to the invention is that, in a two-stage gas sealing system, the second space between the two sealing stages is provided with a first outlet for the transported gas, which is connected to the combustion gas supply line to the gas engine. Thus, the two sealing stages of the gas sealing system can be supplied independently with the coarse gas, the pressure in the second space between the two sealing stages being adjusted to the combustion gas pressure of the gas engine.

Another advantageous embodiment of the turbo-aggregate according to the invention is that upstream of the gas sealing system, two dividing walls are upstream of the housing and the fourth space between these dividing walls is provided with an inert gas inlet which is connected to the exhaust gas exhaust pipe of the gas engine. The combustion gases from the gas engine have the character of an inert gas at = 1 - regulation. The flue gas is introduced into the fourth space between the two partition walls, and part of the flue gas passing around one of these partition walls towards the gas sealing system is sucked in again by the gas engine. The remaining part of the flue gas that passes around the remaining of said partition walls constitutes a shielding against the upstream, oil-lubricated bearing. The partition walls act as a labyrinth seal with respect to the rotor shaft. Combustion gases can be used as an additive to or instead of the air, and in the latter case, even in the case of a large amount of gas escaping, no ignition mixture can be produced.

It is advantageous if the turbo-generator comprises two gas engines, which are optionally connectable to the turbomachine with their exhaust pipes, supply pipes and suction pipes. Gas engines thus form a back-up system. If one of the gas engines fails, the operation of the turbomachine continues to operate independently of the other gas engine.

As an additional safety measure, it is proposed that the second outlet for the mixture of escaping transported gas with the turbo gas is connected via a first connecting fitting to a suction blower which opens into a chimney. Thus, should both gas engines fall out, the escaping transported gas together with the gas may be discharged into the stack. The same is true when working with only one gas engine and it goes out.

In the case of using a two-stage gas sealing system, it is advantageous if the suction fan is also connected to the first outlet for the transported gas from the turbomachine via a second connecting fitting, so that in the event of failure of the gas engine or gas engines.

Also within the scope of the invention are combinations of features of the invention that deviate from the discussed combinations and combinations of features.

BRIEF DESCRIPTION OF THE DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS The invention is illustrated by the following non-limiting examples, which are described with reference to the accompanying drawings which show: 1 is a schematic view of a seal according to the invention; FIG. 2 shows a diagram of the respective turbo aggregate; FIG. 3 shows a modified embodiment of the seal;

FIG. 4 shows a diagram of the turbo-aggregate corresponding to FIG. Third

DETAILED DESCRIPTION OF THE INVENTION

The seal consists of FIG. 1 of the housing 1, in which the rotor shaft 2 is mounted, a dry gas sealing system 3 is disposed between the housing 1 and the rotor shaft 2. This gas sealing system 3 consists of two sealing stages 4, 5. Before the first sealing stage 4 is made up of In a similar manner, a second partition wall 7, which carries the bearing 8, is arranged upstream of the housing 1 from the outside of the housing 1.

Between the first partition 6 and the first sealing stage 4 there is a first space 9, which is equipped with an inlet 10 for transported gas. Between the two separation stages 4, 5 there is a second space 11, which is provided with a first outlet 12 for transported gas. Finally, between the second sealing stage 5 and the second partition wall 7, there is a third space 13, which is equipped with a second outlet 14 of a mixture of escaping transported gas with gas.

FIG. 2, it is evident that the turbine machine is a compressor 15 which operates in the gas transport line 16 and is driven by a gas turbine 17 which is supplied from a combustion gas supply 18 which is branched off the transport gas line 16.

The compressor 15 is part of a turbo-aggregate, in which two gas engines 19, 20 also operate. These gas engines 19, 20 are a combustion gas supply line 2 connected to a combustion gas supply 18 of a gas turbine 17, with a throttle in the supply line 21. element 22 and preheating device 23.

The gas engines 19, 20 are further connected by a common intake manifold 24 for combustion air to a second outlet 14 from the third space 13, the intake manifold 24 having an intake compressor 24 '. The first outlet 12 of the second space 11 is connected to the combustion gas supply line 21 to the gas engines 19, 20.

Purified transport gas is introduced into the first space 9 during operation by the inlet 10. Part of the transported gas passes around the first partition wall 6 and has a sealing effect there. A further part of the transported gas passes through the first sealing stage 4 and enters the second chamber 11. The pressure in this second chamber 11 is adjusted to the pressure in the supply line 21. Part of the transported gas therefore leaves the second chamber 11 through the first outlet 12, 21 into both of the gas engines 19, 20 which is currently in operation. The remainder passes as leaking transported gas through the second sealing stage 5 and arrives in the third space 13, from where it is sucked through the second outlet 14 into the gas engines 19, 20 which is currently in operation. Due to the negative pressure in the third space 13, the air flows around the bearing 8, thereby cooling the bearing 8. The supply air comes as combustion air to the intake gas engine 19, 20. The supply air must not be contaminated with oil. The bearing 8 is preferably formed by a magnetic bearing.

In this way, the leaked transported gas from the gas sealing system 3, in this case for the production of electric current in the generator 25, is utilized energetically. At the same time, cooling of the bearing 8 is ensured by suction of the air. with the possible exception of the suction compressor 24 ', which is used in case the suction vacuum of the gas engine 19, 20 is too low to overcome the pressure losses inside the turbo aggregate. In order to reduce pressure losses, it is further possible to suck air into the third space 13 through additional openings in the housing 1.

The described solution is advantageous from an environmental point of view, because the escaped transported gas does not escape into the atmosphere, but is burned in gas engines 19, 20 that meet environmental protection requirements.

In the suction line 24, which leads from the second outlet 14 of the third space 13 to the gas engines 19, 20, there is a connecting fitting 26, by means of which the suction fan 27 can be connected in the case of both gas engines 19, 20. Similarly, the second connection fitting 28 establishes a connection between the first outlet 12 of the second space 11 and the suction fan 27, so that in the event of the failure of both gas engines 19, 20, also gas can be introduced into the chimney (not shown).

The embodiment of FIG. 3 from the embodiment of FIG. 1 differs in particular in that a third partition 29 is provided outside the housing 1 outside the housing 1, followed by a fourth partition 7 'which carries an oil-lubricated bearing 8'. Between the second partition 7 and the third partition 29 there is a fourth space 30 which is provided with an inert gas inlet 31.

The third space 13 is additionally provided with an air inlet 32 in addition to the second outlet 14. Thus, the gas engine 19, 20 currently in operation draws from the second outlet 14 from the third space 13 a mixture consisting of the escaping transported gas, air and inert gas.

A variation of the embodiment is possible in that the air inlet 32 of FIG. 3. Under these circumstances, the gas engine 19, 20 in operation is sucking from the third compartment 13 a mixture consisting of the escaping transported gas and the inert gas. Even in the event of an unacceptable increase in the amount of gas escaping in the event of failure of the gas sealing system 3, this cannot result in an inflammable or explosive mixture.

Under these circumstances, the gas engines 19, 20 draw their combustion air from the ambient atmosphere.

A portion of the inert gas that flows from the fourth chamber 30 to the oil-lubricated bearing 8 'arrives at the fifth chamber 33, which leaves the third outlet 34. The inert gas thus shields the gas sealing system 3 from the oil-lubricated bearing 8'.

FIG. 4, it is evident that the gas engines 19, 20 are equipped with a flue gas exhaust pipe 35 which is connected via a drying device 36 to an inert gas supply 31 to the fourth space 30. Thus, a portion of the flue gas from the gas engines 19, 20 Fig. Third

Of course, variations are possible within the scope of the invention. For example, instead of having a pair of gas engines, only one gas engine can be operated. In addition, the suction fan can also be discharged if a chimney of adequate draft is available or the tail gas can be discharged to the space where the turbo generator is installed. In addition, gas engines can be connected to a turboexpander instead of a turbocharger. The compressor can be equipped with a piston drive instead of a gas turbine.

Claims (12)

A method of sealing a rotor shaft with respect to a turbo-generator housing operating in a transported gas line, with a dry gas sealing system between the rotor shaft and the housing, wherein a gas medium is introduced into the gas sealing system from the inside and outside of the housing; cleaned transported gas from the outside of the casing and withdrawing a mixture of leaking transported gas with the leaking gas occurring in the gas sealing system on the outside of the casing, characterized in that the leaking transported gas mixture with the leaking gas occurring in the gas sealing system ( 3) on the outside of the housing (1) is sucked out and introduced on the air intake side into the gas engine (19, 20) fed by the otherwise transported gas. Method according to claim 1, characterized in that air is supplied as the obstruction gas on the outside of the housing (1). Method according to claim 2, characterized in that the gas engine (19, 20) sucks a mixture of escaping transported gas with air occurring on the outside of the housing (1), optionally via a suction fan (27). Method according to one of Claims 1 to 3, characterized in that, in the two-stage embodiment of the gas sealing system (3), the gas present between the two sealing stages (4, 5) is transported as combustion gas into the gas engine (19). 20). Method according to one of Claims 1 to 4, characterized in that flue gases from the gas engine (19, 20) are introduced into the gas sealing system (3) from the outside of the housing (1). 6. A turbo-generator with at least one turbomachine operating in a pipeline for transported gas, comprising a housing in which the rotor shaft is assembled, a dry gas sealing system is placed between it and the housing, upstream of which at least one separating device is always upstream and downstream of the housing. wall, wherein the first space between the first partition wall on the inside of the housing and the gas sealing system is provided with a gas inlet (10), while the third space between the partition wall on the outside of the housing and the gas sealing system is provided with a second outlet of the escaping gas with gas, for carrying out the method according to claim 1, characterized in that it comprises at least one gas engine (19, 20) with a flue gas exhaust pipe (35), a combustion gas supply pipe (21) and an intake pipe (24) for combustion air, the intake manifold (24) for combustion Air is connected to the second terminal (14) a mixture of the effluent gas flows to the gas závemým of the turbo-engine (15). Turbo generator according to claim 6, characterized in that a suction compressor (24 ') is arranged between the gas engine (19, 20) and the second outlet (14) of the mixture of the escaping transported gas and the tail gas from the turbomachine (15). Turbo aggregate according to claim 6 or 7, characterized in that in the two-stage gas sealing system (3), the second space (11) between the two sealing stages (4, 5) is provided with a first outlet (12) of the transported gas, which is connected to the combustion gas supply pipe (21) to the gas engine (19, 20). Turbo aggregate according to one of Claims 6 to 8, characterized in that two partitions (7, 29) and a fourth space (30) between these partitions are arranged upstream of the gas sealing system (3) on the outside of the housing (1). (7, 29) is provided with an inert gas inlet (31) which is connected to the exhaust gas pipe (35) of the gas engine (19, 20). Turbo generator set according to one of Claims 6 to 9, characterized in that it comprises two gas engines (19, 20), which are optionally connectable to the turbo-generator unit by means of their exhaust ducts (35), inlet ducts (21) and suction ducts (24). (15). Turbo aggregate according to one of Claims 6 to 10, characterized in that the expensive outlet (14) of the mixture of escaped transported gas and tail gas from the turbomachine (15) is connected to a suction fan (27) via a first connecting fitting (26). mouth into the chimney. Turbo generator according to claim 11, characterized in that the suction fan (27) is connected via a second connecting fitting (28) to the first outlet (12) for the transported gas from the turbomachine (15). 3 drawings