DE4326800A1 - Device for setting a stable compressor admission flow from the inlet box in gas turbine plants - Google Patents

Abstract

In a device for setting a stable compressor admission flow from the inlet box (1) of a gas turbine plant a separating element (2) is arranged in the lower part of the inlet box (1), the peripheral position (@) and the geometric dimensions of the separating element (2) resulting from the marginal conditions at the entry of the inlet box (1) and the transition into the bladed duct. The separating element (2) is a plane separating plate, with large axial and radial distance between bellmouth (5) and inlet box (1) it is a three-dimensional element, which prevents the formation of a wake space (6). A stable compressor admission flow is achieved and the air mass flow is uniformly and precisely distributed over the circumference of the compressor annular chamber (4). As a result, a degree of high efficiency is achieved. <IMAGE>

Description

Technical field

The invention relates to a device for adjusting a stable compressor inflow from the inlet box with gas turbine plants.

State of the art

In industrial gas turbine plants, the required air mass mostly drawn through a single channel. The Ka nalquerschnitt is chosen so that the speed remains small in order to minimize the total pressure loss. First shortly before blading a constriction accelerates the sucked in air to a much higher speed in front of the leading edge of the preliminary row.

For a good efficiency and a good surge limit of the The compressor is a stationary and symmetrical inflow desired in the air. This means that the mass flow uniform and defined over the circumference of the compressor annulus must be distributed.

With conventional infeed boxes, that is in the lower level Separation plane of left and right mass flow only through the Boundary conditions of the flow at the entry into the inlet box  and determined at the outlet into the blading channel. This one Boundary conditions are not precisely defined and are different that change in time and with the load point also changes the dividing plane between the left and right mass flow. The The reason for the change in the boundary conditions is the change the losses of the two partial mass flows at differ Chen volume flows in the gas turbine (partial load). The change tion of the separation plane between the left and right mass flow leads to an asymmetrical and unsteady inflow of the compressor and thus to a deterioration of the we efficiency.

The distance between Bellmouth and the inlet box becomes very chosen large to slow speeds and thereby to achieve a low total pressure drop, which in turn leads to leads to higher efficiency, but then forms in a dead water area from the lower part of the inlet box. The The extent of the dead water area fluctuates transiently, see above that there is an unsteady inflow in the lower region of the Compressor results and the efficiency thereby deteriorate is tert.

Presentation of the invention

The invention tries to avoid all these disadvantages. your the task is based on a gas turbine system Device for setting a stable compressor inflow mung out of the inlet box at which the masses current evenly and defined over the extent of the compression Terringraumes is distributed and the formation of a dead water is prevented.

According to the invention this is achieved in that in the lower Part of the inlet box, a separating body is arranged, wherein the circumferential position and the geometric dimensions of the  Partition from the boundary conditions at the inlet of the inlet box and at the transition into the bladed channel.

The advantages of the invention include that a stable compressor inflow is achieved and the Air mass flow evenly and defined over the circumference of the compressor annulus is distributed.

It is particularly useful if the separating body is flat Divider is.

It is also advantageous if the separating body is large Distance between Bellmouth and inlet box a defined is three-dimensional body. This is training a dead water area prevented and a stable compression Inflow reached.

Brief description of the drawing

In the drawing is an embodiment of the invention on the basis of a single-shaft compressor with axial flow Gas turbine plant shown.

Show it:

Fig. 1 shows a partial longitudinal section of the inlet box, compression ring space and the preliminary row of the compressor;

Fig. 2 shows a partial cross section of the inlet box with the separating body.

It is only essential for understanding the invention Chen elements shown. The flow direction of the air masses currents is indicated by arrows.  

Way of carrying out the invention

In the partial longitudinal section shown in FIG. 1 of a single-shaft axial-flow compressor 3 , the inlet box 1 with the separating body 2 , the compressor annulus 4 , Bellmouth 5 and the inlet row 7 of the compressor can be seen. In this case, the separating body 2 is a flat separating plate with a height h, which is inserted at a defined point in the lower part of the inlet box 1 . The circumferential position α (see FIG. 2) and the height h result from the boundary conditions at the inlet of the inlet box 1 and at the transition into the channel that is scooped.

A circumferential position α deviating from 0 ° results if the incorrect flow from the guide line in the left and right part of the inlet (partial mass flows 8 , 9 ) is very different (abdominal and back abutment).

In order to keep the total pressure loss from entry into the inlet box 1 to the outlet on the preliminary row for the left partial mass flow 8 and the right partial mass flow 9 equal, a position of the separating plane deviating from 0 ° can be selected.

The separating plate brings about a definite separation between the left partial mass flow 8 and the right partial mass flow 9 , so that a steady and symmetrical inflow is achieved, which leads to a good efficiency and a good pump limit of the compressor 3 .

In a second embodiment, the separating body 2 is a three-dimensional structure such that a dead water area 6 that may form is filled. Derar term dead water areas 6 then form in the lower part of the inlet box 1 when the axial and radial distance between Bellmouth 5 and the inlet box 1 is selected very large to have the lowest possible speeds and thereby to minimize the total pressure loss. The expansion of the dead water area 6 fluctuates transiently, so that there is an unsteady inflow in the lower region of the United poet 3 . Only if the separating body 2 is designed as a three-dimensional body that at least approximately fills the dead water area 6 can the unsteady flow be avoided. This increases the efficiency of the compressor 3 .

Reference list

1 inlet box
2 separators
3 compressors
4 compressor annulus
5 Bellmouth
6 dead water area
7 preliminary series
8 left partial mass flow
9 right partial mass flow
h Height of the separating body
α circumferential position of the separating body

Claims (3)

1. Device for setting a stable Verdichterzu flow from the inlet box ( 1 ) in Gasturbinenanla gene, characterized in that in the lower part of the inlet box ( 1 ) a separating body ( 2 ) is arranged, the circumferential position (α) and the geometric dimensions of the separator ( 2 ) from the boundary conditions at the inlet of the inlet box ( 1 ) and at the transition to the bladed channel. 2. Device according to claim 1, characterized in that the separating body ( 2 ) is a flat partition. 3. Apparatus according to claim 1, characterized in that the separating body ( 2 ) with a large axial and radia len distance between Bellmouth ( 5 ) and inlet box ( 1 ) is a three-dimensional body which at least approximately fills up the dead water area ( 6 ).