Abstract: Exhaust frequency mitigation apparatus, exhaust diffusers, and turbomachines are provided. An exhaust frequency mitigation apparatus includes a main body extending along an axial centerline from a base to a tip. the base defines a first diameter and the tip defining a second diameter. the main body converges from the first diameter to the second diameter with respect to the axial centerline. The base is configured to extend from an inner shell of a turbomachine exhaust diffuser. The exhaust frequency mitigation apparatus further includes at least one rib extending from a root coupled to the main body to a free end.

Abstract: Exhaust frequency mitigation apparatus, exhaust diffusers, and turbomachines are provided. An exhaust frequency mitigation apparatus includes a main body extending along an axial centerline from a base to a tip. the base defines a first diameter and the tip defining a second diameter. the main body converges from the first diameter to the second diameter with respect to the axial centerline. The base is configured to extend from an inner shell of a turbomachine exhaust diffuser. The exhaust frequency mitigation apparatus further includes at least one rib extending from a root coupled to the main body to a free end.

Abstract: An exhaust system for use with a steam turbine is provided. An exhaust hood includes an input and an output, the input receiving fluid from the steam turbine. The exhaust hood includes a first side wall that extends between the input and the output. The first side wall includes an aperture. An ejector is coupled to the exhaust hood. The ejector includes inlets and an outlet. At least one of the inlets receives fluid from the exhaust hood via the aperture.

Abstract: An asymmetric butterfly plate for a steam turbine exhaust hood includes a non-symmetrical curvilinear profile having a first section that extends to a second section through a vertex. The first section has a first curvilinear profile and the second section has a second curvilinear profile that is distinct from the first curvilinear profile.

Abstract: A steam turbine exhaust hood includes an exhaust hood section, and a butterfly plate arranged in the exhaust hood section. The butterfly plate includes a complex curvilinear cross-sectional profile having a first section that extends between a first end portion and a middle portion, and a second section that extends between the middle portion and a second end portion. One of the first and second sections is formed from at least two curvilinear segments including at least one curvilinear segment having a positive curvature and at least one curvilinear segment having a negative curvature.

Abstract: Various embodiments of the invention include a system including: at least one computing device operably connected with a steam turbomachine and an extraction conduit fluidly connected with the steam turbomachine and a steam seal header fluidly coupled with the steam turbomachine, the at least one computing device configured to modify an output of the steam turbomachine by performing actions including: determining a pressure within the steam turbomachine; comparing the pressure within the steam turbomachine with a pressure threshold range; and instructing the extraction conduit to extract steam seal header steam from the steam seal header and provide the extracted steam seal header steam to the steam turbomachine in response to determining the pressure within the steam turbomachine deviates from the pressure threshold range.

Abstract: Various embodiments of the invention include a system including: at least one computing device operably connected with a steam turbomachine and an extraction conduit fluidly connected with the steam turbomachine and a steam seal header fluidly coupled with the steam turbomachine, the at least one computing device configured to modify an output of the steam turbomachine by performing actions including: determining a pressure within the steam turbomachine; comparing the pressure within the steam turbomachine with a pressure threshold range; and instructing the extraction conduit to extract steam seal header steam from the steam seal header and provide the extracted steam seal header steam to the steam turbomachine in response to determining the pressure within the steam turbomachine deviates from the pressure threshold range.

Abstract: Various embodiments include a turbomachine exhaust diffuser. In some embodiments, the turbomachine diffuser includes an inlet, an outlet opposing the inlet along a primary axis of the turbomachine diffuser, and a diffuser region between the inlet and the outlet. The diffuser region can include: a radially outer wall and a radially inner wall opposing the radially outer wall. The radially inner wall can include: a first section including a substantially uniform slope, and a second section continuous with the first section, the second section having a non-uniform slope.

Abstract: An exhaust system for use with a steam turbine is provided. An exhaust hood includes an input and an output, the input receiving fluid from the steam turbine. The exhaust hood includes a first side wall that extends between the input and the output. The first side wall includes an aperture. An ejector is coupled to the exhaust hood. The ejector includes inlets and an outlet. At least one of the inlets receives fluid from the exhaust hood via the aperture.

Abstract: An exhaust diffuser for a turbine includes an inlet configured to receive exhaust gas from a last stage bucket of the turbine and an exhaust gas guide surface configured to guide the exhaust gas. A curvature of the guide surface comprises a first angle with respect to an axis of the turbine and a ratio of a guide surface axial length to the active length of the last stage bucket which is between about 0.45 to 0.70. A method of diffusing exhaust of a turbine includes energizing a boundary layer along a curved exhaust flow guide surface of an exhaust diffuser with over tip leakage of a last stage bucket of the turbine.

Abstract: Tip shrouds on last stage buckets for condensing steam turbines may create significant blockage and form a vortex at the wall of the steam guide of the diffuser, causing the steam flow to separate from the wall of the steam guide. Vortex formation reduces the effective flow area for the remaining fluid to diffuse, causing poor recovery. An inward radial depression is provided of a predetermined depth and distance along an outer steam guide, which redirects the tip leakage flows slightly downward, reducing a shroud blockage effect. This deflection assists the main flow in rejoining the steam guide, thereby making the diffuser more effective.

Abstract: An asymmetric butterfly plate for a steam turbine exhaust hood includes a non-symmetrical curvilinear profile having a first section that extends to a second section through a vertex. The first section has a first curvilinear profile and the second section has a second curvilinear profile that is distinct from the first curvilinear profile.

Abstract: A steam turbine exhaust hood includes an exhaust hood section, and a butterfly plate arranged in the exhaust hood section. The butterfly plate includes a complex curvilinear cross-sectional profile having a first section that extends between a first end portion and a middle portion, and a second section that extends between the middle portion and a second end portion. One of the first and second sections is formed from at least two curvilinear segments including at least one curvilinear segment having a positive curvature and at least one curvilinear segment having a negative curvature.

Abstract: Tip shrouds on last stage buckets for condensing steam turbines may create significant blockage and form a vortex at the wall of the steam guide of the diffuser, causing the steam flow to separate from the wall of the steam guide. Vortex formation reduces the effective flow area for the remaining fluid to diffuse, causing poor recovery. An inward radial depression is provided of a predetermined depth and distance along an outer steam guide, which redirects the tip leakage flows slightly downward, reducing a shroud blockage effect. This deflection assists the main flow in rejoining the steam guide, thereby making the diffuser more effective.