FI73047B - FARING EQUIPMENT FOR ORGANIZATION OF AVGASURBIN. - Google Patents

Description

73047

METHOD AND ARRANGEMENT FOR WASHING AN EXHAUST GAS TURBINE - FOR A FAR RANGE FOR EXHAUST TURBINE

The invention relates to a method for cleaning an exhaust gas turbine of an internal combustion engine according to the preamble of claim 1, in which the scrubbing liquid is introduced into the exhaust gas before the turbine, and to an arrangement for applying the method.

The exhaust gases of an internal combustion engine, especially a heavy fuel oil diesel engine, contain a large amount of solid combustion waste. When these gases are introduced into the turbine, this becomes contaminated quite quickly. Karst accumulates e.g. the turbine wheel and turbine nozzle ring vanes, from which it must be removed from time to time to ensure efficient operation of the turbine. In connection with maintenance, in which the exhaust turbine is otherwise taken into account, the turbine wheel and the nozzle ring are cleaned, for example, with a nylon or brush brush by light brushing or scraping with a plastic spatula. However, efforts have recently been made to extend the service intervals of internal combustion engines, and today they are often too long for the rapid fouling of turbines. Depending on the driving style and the characteristics of the internal combustion engine, the cleaning of the turbine must be carried out every 50 to 200 hours of operation, whereas the service interval of the turbocharger is usually about 3000 hours of operation. In this case, there is a need to develop new cleaning methods that would enable simple and efficient cleaning of turbine parts even between maintenance.

According to the prior art flange with valves, through which water is introduced to the exhaust gas among the exhaust gas held in the first half of the channel box. In this case, the distance from the wash water valves to the nozzle ring and the turbine wheel is usually about 40-50 cm. Due to the high temperature of the exhaust gases, the washing water evaporates, which tends to reduce the washing efficiency. To reduce evaporation during washing, the exhaust gas temperature must be reduced by reducing the internal combustion engine speed. This operation, in turn, prolongs the washing time, and thus also causes corrosion and erosion phenomena in the machine parts with which the gas vapor comes into contact.

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The object of the invention is to provide an inexpensive and simple method of washing an exhaust gas turbine, which avoids the said problems of the prior art by providing a more efficient turbine washing.

The method according to the invention is characterized in that the turbine is cleaned while the machine is running by spraying the washing liquid directly towards the turbine nozzle ring from the washing liquid nozzles arranged in the exhaust flow direction immediately before the nozzle ring. In this way, evaporation of the washing liquid can be avoided and an efficient and uniform washing result is achieved. An additional advantage is the reduction in the amount of washing liquid required, which tends to reduce corrosion.

The wash fluid can be sprayed from a location within either the inner or outer circumference of the turbine nozzle ring. The advantage of the washing liquid nozzles located outside is that the installation of the washing liquid filling lines is easier to arrange. The washer fluid nozzles should preferably be provided for each vane nozzle ring vane.

The optimum pressure of the spray liquid to be sprayed depends mainly on the pressure of the exhaust gases. The dimensions of the exhaust ducts and the location of the wash ring or tires also affect this optimum pressure. It has been found that the commonly used dimensions achieve a good washing result when the pressure of the washing liquid is 1.5 ... 6 times the pressure of the exhaust gases, whereby the optimum can be found in the range 2 ... 4 times the pressure of the exhaust gases.

As the washing liquid, water can be preferably used, the washing capacity of which has usually been found to be completely sufficient.

To apply the method according to the invention, an arrangement can be used which comprises a scrubbing ring arranged in the flow direction of the packing gases immediately before the nozzle ring. With the nozzle and turbine ring, the concentric scrubber preferably has an annular main passage from which the substantially radial injection passages terminate in the exhaust passage. At the end of the injection ducts, the injection ducts preferably have a directional component in the direction of the exhaust gas flow, i.e. the injection duct forms an acute angle with the exhaust gas flow. This angle is 50 ° ... 85 °, preferably 60 ° to 80 °. The wash ring is made of a material that is heat resistant and highly corrosion resistant up to at least about 700 ° C.

The invention will now be described in more detail with reference to the accompanying drawing, in which Figure 1 shows a section of a washing arrangement according to the invention placed in a turbocharger, Figure 2 shows a detail according to Figure 1, Figure 3 shows a section of Figure 1 in plane B-B.

In the figure, reference numeral 1 refers to the turbine wheel of the exhaust gas turbine, which in the exhaust gas flow direction A

viewed preceded by a stationary nozzle ring 2 concentric with the turbine wheel 1, formed by an inner circumference 2a and an outer circumference 2b, and between them nozzle ring nozzles 2, the walls of which the outer ring. The exhaust gases are introduced from the internal combustion engine into the exhaust gas turbine via the exhaust gas duct 5. The vanes 3 of the nozzle ring 2 direct the exhaust gases towards the turbine blades of the turbine wheel 1 =

The turbine wheel 1 rotates supported by bearings 12 in a known manner due to the exhaust gas flows, while rotating the internal combustion engine supercharger 8 via the shaft 7. The supercharger 3 introduces supercharged air into the internal combustion engine from where it:

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In the flow direction of the exhaust gases immediately before the nozzle ring 2, a scrubber gas 9 »with a main channel 10 is arranged concentrically therewith. The radial injection channels 11 of the ring 9 start from the annular main duct 10 and end in the exhaust duct 5. The injection ducts 11 are as many as the wings 3 of the nozzle ring 2 and are arranged so that one injection duct 11 terminates in front of each nozzle blade. is 50 ° to 85 °, preferably 60 ° to 80 °. In the preferred embodiment, no separate members are required to fasten the wash ring, but the fastening to the stationary position is performed by means of a nozzle ring.

The exhaust turbine is always shaken every certain number of operating hours, during which the internal combustion engine is operated and pressurized water is introduced into the main duct 10 of the base ring 9. The drawing does not show a water inlet duct arranged in a known manner. The engine speed and wash water pressure must then be selected so that the wash water pressure is at least one and a half times the exhaust pressure. Due to the pressure differences, the wash water now sprays from the injection ducts 11 to the exhaust duct 5, from where the wash water streams are directed directly to the nozzle ring blades 3, effectively washing the dirty blades 3 and the turbine wheel 1.

This provides an efficient scrubbing system with a simple construction that makes it easy to keep the exhaust turbine of the internal combustion engine clean.

The invention is not limited to the embodiment shown, but several variations thereof are conceivable within the scope of the appended claims.

Claims (10)

1. Combustion engine exhaust turbine cleaning method, according to which washing liquid is supplied to the exhaust gas before the turbine, which comprises a turbine wheel (1) and a nozzle ring (2) arranged in the direction of exhaust flow, characterized in that the cleaning of the turbine takes place during the washing of the machine by spraying the machine the turbine nozzle ring (2) by washing liquid nozzles arranged in the direction of exhaust flow immediately before the nozzle ring, so that the wash liquid is directed straight to the surface of the nozzle ring vanes (3) · Cleaning method according to claim 1, characterized in that the washing liquid is sprayed from a position located at the area of the outer periphery (2b) of the nozzle ring. 3- The cleaning method according to claim 1 or 2, characterized in that the wash water is sprayed from a position located at the area of the inner circumference of the nozzle ring (2a). Cleaning process according to any of the preceding claims, characterized in that the washing liquid to be sprayed has a pressure of 1.5 ... 6, preferably 2 ... 4 times the pressure of the exhaust gas. Cleaning process according to any of the preceding claims, characterized in that water is used as a washing liquid. Apparatus for applying a method according to any one of the preceding claims, characterized in that it comprises a washing ring (9) arranged in the direction of exhaust of the exhaust gas (2), which comprises a preferably annular main channel (10) for the washing liquid, and from this (10) exit mainly radially directed spray channels (11), which extend into the exhaust duct (5). Device according to claim 6, characterized in that there is a spray channel (11) for each vane (3) of the turbine nozzle, such that the washing liquid to be sprayed is directed straight against the wall of each vane (3). 8. Apparatus according to claim 6 or 7, characterized in that the spray channels (11) have a directional component which stays in the direction of the exhaust gas flow at the end of the spray channels. Device according to any one of claims 6-8, characterized in that the wink (a) between the spray channel and the exhaust flow is 50 ° ... 85 °, preferably 60 ° ... 80 °. 10. Device according to any of claims 6-9, characterized in that the wash ring (9) consists of a material which is well corrosion resistant in 700 ° C teratum.