Turbomachine assembly
The present disclosure relates to a turbomachine assembly, which includes a shaft, a radial gas expander supported on the shaft between a first bearing and a second bearing, and a compressor supported on the shaft in overhung position adjacent to one or the other of the first and second bearings. The compressor includes a plurality of movable inlet nozzles and the radial gas expander includes a plurality of movable guide vanes.
1. A turbomachine assembly comprising:
a single shaft;
a radial gas expander supported on the single shaft between at least one first bearing and at least one second bearing, the radial gas expander comprising at least two radial stages coupled via an interstage path, the at least two radial stages including a high pressure stage and a low pressure stage, a plurality of movable guide vanes comprising a first set of movable guide vanes in the high pressure stage and a second set of movable guide vanes in the low pressure stage, a plurality of struts included in the interstage path configured to guide a gas flow from the high pressure stage to the low pressure stage; and
a compressor supported on the single shaft in an overhung position adjacent to at least one of the first or second bearing, the compressor including a plurality of movable inlet nozzles,
wherein the movable inlet nozzles and the movable guide vanes are configured to permit varying operating points of the radial gas expander and the compressor, respectively, such that the operating points of the radial gas expander and the compressor are varied independently from one another without needing to differentiate the relevant speeds enabling the single shaft to be used for both the radial gas expander and the compressor,
wherein an operative gas of the radial gas expander is different from a process gas of the compressor, and
wherein at least a seal is provided on the single shaft between the compressor and the radial gas expander to separate the operative gas of the radial gas expander from the process gas of the compressor.
2. The turbomachine assembly according to claim 1 , wherein the first set of movable guide vanes and the second set of movable guide vanes are actuated independently from relative to each other.
3. The turbomachine assembly according to claim 1 , wherein the radial gas expander is part of an organic Rankine cycle.
4. The turbomachine assembly according to claim 1 , wherein the single shaft operates at a variable speed.
5. The turbomachine assembly according to claim 1 , wherein the single shaft operates at a constant speed.
6. The turbomachine assembly according to claim 1 further comprising a balance drum located at an axial end of the single shaft and opposite the compressor, the balance drum configured to compensate a sum of axial forces generated during operation by the compressor and the radial gas expander.
7. The turbomachine assembly according to claim 1 , wherein the operative gas (i) enters the high pressure stage radially, flows through the first set of movable guide vanes, and then through an impeller of the high pressure stage, (ii) exits the high pressure stage axially and is guided by the interstage conduit to enter the low pressure stage radially after flowing through the second set of movable guide vanes, and (iii) exits the low pressure stage axially and is directed outside the turboexpander by an axial outlet.
8. The turbomachine assembly according to claim 1 , wherein the radial expander comprises an additional stage having fixed inlet guide vanes.
9. The turbomachine assembly according to claim 1 , further comprising an electric generator adjacent to the at least one first bearing and the at least one second bearing.