Turbomachinery

Patent metadata

Field	Value
Publication number	US-11111792-B2
Application number	US-201916282976-A
Country	US
Kind code	B2
Filing date	Feb 22, 2019
Priority date	Aug 24, 2018
Publication date	Sep 7, 2021
Grant date	Sep 7, 2021

Abstract

A turbomachine (105) configured to compress supercritical carbon dioxide is shown. The turbomachine comprises, in fluid flow series, an inlet (201), an inducerless radial impeller (202) having a plurality of blades, and a fully vaneless diffuser (203). The radius of the inlet (r0) is from 25 to 50 percent of the radius of the impeller (r2).

First claim

The invention claimed is:

1. A turbomachine configured to compress supercritical carbon dioxide, the turbomachine comprising, in fluid flow series:
an inlet;
an inducerless radial impeller having a plurality of blades; and
a fully vaneless diffuser;
wherein a hub hade angle of the impeller at an entry thereto (γ 1hub ) is from 50 to 70 degrees, and
wherein the hub hade angle is defined by an axial line of the inlet and a tangent line that is tangent to a point of the impeller where the blade of the impeller begins.

2. The turbomachine of claim 1 , in which a radius of the inlet (r 0 ) is from 30 to 50 percent of a radius of the impeller (r 2 ).

3. The turbomachine of claim 1 , in which the inlet is radially flared to induce a radial component in flow prior to an entry to the impeller.

4. The turbomachine of claim 1 , in which a radius of the inlet (r 0 ) is from 25 to 50 percent of a radius of the impeller (r 2 ).

5. The turbomachine of claim 1 , in which said hade angle (γ 1hub ) is 60 degrees.

6. The turbomachine of claim 1 , in which each of the plurality of blades is a backswept blade.

7. The turbomachine of claim 6 , in which each of the plurality of blades have a blade exit angle (χ 2 ) of from −50 to −70 degrees.

8. The turbomachine of claim 7 , in which each of the plurality of blades have a blade exit angle (χ 2 ) of −60 degrees.

9. The turbomachine of claim 1 , in which the plurality of blades comprises:
a set of main blades; and
a set of splitter blades.

10. The turbomachine of claim 9 , in which a meridional chord length of the splitter blades (c s ) is 70 percent of a meridional chord length of the main blades (c m ).

11. The turbomachine of claim 9 , in which the impeller comprises one splitter blade for each main blade.

12. The turbomachine of claim 1 , in which the diffuser has a height (b 2 ) at an entry of the diffuser and a height (b 3 ) at an exit of the diffuser, with an annulus height ratio and the entry and the exit of the diffuser (b 3 /b 2 ) being 1.

13. The turbomachine of claim 1 , in which a radius of the diffuser (r 3 ) is from 1.2 to 1.8 times larger than a radius of the impeller (r 2 ).

14. The turbomachine of claim 13 , in which the radius of the diffuser (r 3 ) is from 1.3 to 1.7 times larger than the radius of the impeller (r 2 ).

15. The turbomachine of claim 1 , further comprising a volute arranged to receive fluid from the diffuser, said volute comprising a tongue and having a flow area at the tongue equal to that of the diffuser.

16. The turbomachine of claim 1 , having the inlet, the impeller and the diffuser configured to achieve a design point stagnation pressure ratio of 2 or greater when the impeller is rotated at a speed of at least 50000 revolutions per minute.

17. The turbomachine of claim 1 , further comprising a plenum arranged to receive fluid from the diffuser, said plenum comprising a connector having a cross-sectional area equal to the cross-sectional area of the inlet divided by a design point stagnation pressure ratio of the turbomachine that is achieved by a combination of the inlet, the impeller and the diffuser when the impeller is rotated at a speed of at least 50000 revolutions per minute.

18. A method of operating the turbomachine of claim 1 , comprising:
supplying supercritical carbon dioxide to the inlet of the turbomachine; and
rotating the impeller.

19. The method of claim 18 , in which the supercritical carbon dioxide is supplied at 306 kelvin and at 7.7 megapascals and the impeller is rotated with a speed of at least 50000 revolutions per minute.

20. A system that is a closed, indirect-heated Brayton cycle having a carbon dioxide working fluid and comprising the turbomachine of claim 1 .

Assignees

• Rolls Royce Plc

Inventors

• Goodhand Martin N
• Bunce Ian M

Classifications

• F02C1/10

  Closed cycles · CPC title

• F05D2250/70

  Shape · CPC title

• F02C1/04

  the working fluid being heated indirectly {(in a fluidised-bed combustor F02C3/205)} · CPC title

• F05D2240/301

  Cross-sectional characteristics · CPC title

• F01K7/32

  the engines using steam of critical or overcritical pressure · CPC title