Cooling system and method for cooling a turbo-machine housing

#The invention relates to a cooling system as well as a method for cooling thermally stressed housings or housing parts in turbo-machines, in particular in a turbine.

#In order to cool a housing or housing parts of a turbo-machine, in particular that of a turbine, feeder air, which is usually sucked in from the area around the housing, is fed into the housing. When flowing through the housing, this air is then heated and is removed from the housing as waste air. For this purpose, a conventional cooling system has a feeder air line that connects a feeder air connection of the housing with an area around the housing in order to feed the feeder air through the feeder air line into the housing. Also provided is a waste air line that is connected with a waste air connection of the housing in order to remove the waste air heated by the housing. A fan that circulates the cooling air flow is positioned inside the feeder air line. In order to influence the cooling performance of such a cooling system, it is known to change the speed of the fan, for example by means of a gear. In the same way, the use of closing elements, such as, for example, butterfly valves, gate valves, or shutter-type valves, are known, with which the cooling air flow or parts thereof can be influenced or locked out. By means of these measures, the air volume fed into the housing for cooling, i.e. the feeder air volume, is therefore adjusted in order to change the cooling performance of the cooling system.

#In order for the cooling of the housing to be able to function properly, clear and reproducible flow conditions must exist during the flow through the housing. This is only possible, however, if the added feeder air does not vary too much from a cooling air volume on which the design of the cooling system is based. This means that only a relatively small adjustment range is available for changing the feeder air volume. Furthermore, a temperature gradient that may result in undesired tensions in the housing forms along the flow path within the housing.

#A preferred embodiment of the invention is disclosed in the following description and illustrated in the accompanying drawing, in which:

#FIG. 1 shows a schematic view of a cooling system according to an embodiment of the invention.

#FIG. 1 is an illustration of a housing or housing part 1 in a turbo-machine, (not shown) (otherwise), for example a turbine, indicated by a rectangle. The housing 1 is cooled using a cooling system 2 according to the invention. For this purpose, the cooling system 2 comprises a feeder air line 3 that is connected to a feeder air connection 4 of the housing 1. Inside the housing 1, a flow path, (not shown), is realized, which communicates on the inlet side with the feeder air connection 4 and on the outlet side with a waste air connection 5 of the housing 1. To this waste air connection 5, a waste air line 6 of the cooling system 2 is connected. In the feeder air line 3, a fan 7 is positioned whose drive motor 8 can be operated via a control line 9 from a control device 10 of the cooling system 2. In the embodiment illustrated here, the fan 7 can be adjusted with respect to its fan output. For example, the air mass circulated by the fan 7 can be adjusted by way of the speed of the drive motor 8.

#The cooling system 2 furthermore comprises a recirculated air line 11, with which the feeder air line 3 is connected upstream from the fan 7 with the waste air line 6. In this recirculated air line 11 is positioned a recirculated air closing element 12 that can be adjusted by means of an associated control element 13. The control element 13 is again operated via corresponding control line 14 that is connected with the control device 10. The control element 13 in particular can be used to adjust the opening cross-section of the recirculated air closing element 12 between a completely locked locking position and a completely open opening position, whereby at least one intermediate position can also be set.

#In the feeder air line 3, a feeder air closing element 15 is positioned upstream from the recirculated air line 11, which feeder air closing element can be adjusted by way of an associated control element 16 that is operable via a control line 17 again from the control device 10. The feeder air closing element 15 preferably can also be adjusted between a completely open opening position and a completely closed closing position, whereby at least one intermediate position can also be set.