Method for operating a turbomachine, wherein an efficiency characteristic value of a stage is determined, and turbomachine having a device for carrying out the method

Abstract

A turbo-machine, which can be operated in an optimized driving range is provided. To this end, a method for operating a turbo-machine having at least one turbo-machine stage, which has at least one rotary shaft is disclosed. According to the method, the following method steps are carried out: a) determining a desired efficiency characteristic value .sub.soll of the turbomachine stage; b) determining an actual efficiency characteristic value .sub.ist of the turbo-machine-stage; c) determining a comparison efficiency characteristic value of the turbo-machine stage by comparing the actual efficiency characteristic value .sub.ist and the desired efficiency characteristic value .sub.soll to one another; and d) changing at least one operating parameter of the turbo-machine stage subject to the comparison efficiency characteristic value .sub.vgl, wherein in order to determine the actual efficiency characteristic value .sub.ist, a measuring of a torque of the rotary shaft of the turbo-machine-stage is carried out.

Claims

1. A method for operating a turbomachine including at least one turbomachine stage with at least one rotary shaft, the method comprising: a) determining a desired efficiency characteristic value .sub.soll of the at least one turbomachine stage; b) establishing an actual efficiency characteristic value .sub.ist of the at least one turbomachine stage; c) establishing a comparison efficiency characteristic value .sub.vgl of the at least one turbomachine stage by comparing the actual efficiency characteristic value .sub.ist and the desired efficiency characteristic value .sub.soll to one another; and d) modifying at least one operating parameter of the at least one turbomachine stage in a manner dependent on the comparison efficiency characteristic value .sub.vgl, wherein a torque of the at least one rotary shaft of the at least one turbomachine stage is measured for establishing the actual efficiency characteristic value .sub.ist.

2. The method as claimed in claim 1, wherein a multistage turbomachine comprising at least one further turbomachine stage with at least one further rotary shaft is used as turbomachine.

3. The method as claimed in claim 2, further comprising: a) determining a further desired efficiency characteristic value .sub.soll of the at least one further turbomachine stage; b) establishing a further actual efficiency characteristic value .sub.ist of the at least one further turbomachine stage; c) establishing a further comparison efficiency characteristic value .sub.vgl of the at least one further turbomachine stage by comparing the further actual efficiency characteristic value .sub.ist and the further desired efficiency characteristic value .sub.soll to one another; and d) modifying at least one further operating parameter of the at least one further turbomachine stage in a manner dependent on the further comparison efficiency characteristic value .sub.vgl.

4. The method as claimed in claim 3, wherein a further torque of the at least one further rotary shaft of the at least one further turbomachine stage is measured for establishing the further actual efficiency characteristic value .sub.ist.

5. The method as claimed in claim 1, wherein a contactless measurement method is carried out for measuring the torque of the at least one rotary shaft and/or for measuring the further torque of the at least one further rotary shaft.

6. The method as claimed in claim 5, wherein the contactless measurement method is carried out with the aid of at least one magnetoelastic torque sensor.

7. The method as claimed in claim 6, wherein a compressor is used as turbomachine and an actual efficiency characteristic value .sub.ist and/or a further actual efficiency characteristic value .sub.ist is/are used, which emerge from the following equation:
.sub.i=P1.sub.i/P2.sub.i, where P1.sub.i=volumetric flow rate through the respective turbomachine stage ipressure difference .sub.i at the turbomachine stage i P2.sub.i=torque at the rotary shaft of the turbomachine stage irotational speed of the rotary shaft of the turbomachine stage i.

8. The method as claimed in claim 1, wherein the turbomachine is selected from the group consisting of: gas turbine, steam turbine, turbocharger, pump, compressor, and hydroturbine.

9. The method as claimed in claim 1, wherein a volumetric flow rate of a fluid at the at least one turbomachine stage, with which fluid the turbomachine stage is operated, and/or a rotational speed, with which the at least one rotary shaft of the at least one turbomachine stage is driven, is/are used as operating parameter and/or as further operating parameter.

10. A turbomachine comprising at least one turbomachine stage with at least one rotary shaft, wherein the turbomachine comprises a device for carrying out the method as claimed claim 1.

11. The turbomachine as claimed in claim 10, wherein the turbomachine comprises at least one further turbomachine stage with at least one further rotary shaft.

12. The turbomachine as claimed in claim 11, wherein a torque sensor is arranged at the at least one rotary shaft for establishing the actual efficiency characteristic value .sub.ist of the at least one turbomachine stage and/or a further torque sensor is arranged at the at least one further rotary shaft for establishing the further actual efficiency characteristic value .sub.ist of the at least one turbomachine stage.

13. The turbomachine as claimed in claim 12, wherein the torque sensor and/or the further torque sensor is/are a contactless torque sensor.

14. The turbomachine as claimed in claim 13, wherein the contactless torque sensor is a magnetoelastic torque sensor.

15. The turbomachine as claimed claim 10, wherein the turbomachine is selected from the group consisting of: gas turbine, steam turbine, turbocharger, pump, compressor and hydroturbine.

Description

BRIEF DESCRIPTION

(1) Some of the embodiments will be described in detail, with reference to the following figures, wherein like designations denote like members, wherein:

(2) FIG. 1 shows an embodiment of a single-stage, single-shaft compressor;

(3) FIG. 2 shows an embodiment of a multistage, single-shaft compressor; and

(4) FIG. 3 shows an embodiment of a geared compressor.

DETAILED DESCRIPTION

(5) What is shown is a turbomachine 1 in the form of a turbocompressor with at least one compressor stage (turbomachine stage) 11. The compressor stage 11 has a rotary shaft 111.

(6) A torque sensor 112 for establishing the actual efficiency characteristic value .sub.ist of the compressor stage 11 is arranged at the rotary shaft 111. The torque sensor 112 is a magnetoelastic torque sensor.

(7) The turbocompressor 1 has a device 100 for carrying out an operating method comprising the following method steps:

(8) a) determining the desired efficiency characteristic value .sub.soll of the compressor stage 11,

(9) b) establishing the actual efficiency characteristic value .sub.ist of the compressor stage 11,

(10) c) establishing the comparison efficiency characteristic value .sub.vgl of the compressor stage 11 by comparing the actual efficiency characteristic value .sub.ist and the desired efficiency characteristic value .sub.soll to one another and

(11) d) modifying at least one operating parameter of the compressor stage 11 in a manner dependent on the comparison efficiency characteristic value .sub.vgl.

(12) A torque of the rotary shaft 111 of the compressor stage 11 is measured with the aid of the magnetoelastic torque sensor 112 for establishing the actual efficiency characteristic value .sub.ist. To this end, the rotary shaft 111 consists of ferroelectric material. In an alternative exemplary embodiment, the rotary shaft 111 has a ferroelectric coating securely connected to the rotary shaft 111.

(13) The actual efficiency characteristic value .sub.ist of the compressor stage 11 is established according to equation (1). Likewise, the desired efficiency characteristic value .sub.soll is determined more or less directly after completion of the turbocompressor 1.

(14) The volumetric flow rate across the compressor stage 11, to be measured for P1 (according to equation (1), is measured with the aid of a volumetric flow rate metering orifice 114.

(15) Furthermore, the pressure difference p 115 between the front side 116 and rear side 117 of the compressor stage 11, which is required for P1, is measured.

(16) The torque at the rotary shaft 111 is measured for P2 (according to equation (1) as described above. The rotational speed 113 of the rotary shaft 111 of the compressor stage 11 is known in each case.

(17) The of the comparison efficiency characteristic value .sub.vgl of the compressor stage 11 emerges from the comparison between the actual efficiency characteristic value .sub.ist and the desired efficiency characteristic value .sub.soll.

(18) At least one operating parameter of the compressor stage 11 is varied in a manner dependent on the comparison efficiency characteristic value .sub.vgl. To this end, use is made of pump regulation 118. The operating parameter is the rotational speed 115 of the rotary shaft 111, which is modifiable by way of the actuation of the motor 13, and/or the volumetric flow rate of the fluid, which is modifiable by way of the volumetric flow rate metering orifice.

Example 1

(19) The turbocompressor 1 is an (axially or radially operated) single-shaft compressor (compressor with only one rotary shaft, FIG. 1).

Example 2

(20) In contrast to example 1, the turbocompressor 1 is a multistage, single-shaft compressor (FIG. 2). The turbocompressor 1 comprises a turbocompressor stage 11 and at least one further turbocompressor stage 12.

(21) The rotary shaft 111 of the compressor stage 11 and the further rotary shaft 121 of the further compressor stage 12 form a common rotary shaft.

(22) A further magnetoelastic torque sensor 122 is arranged at the further compressor stage 12. The further torque is picked off in the region of the further rotary shaft 121 with the aid of the further torque sensor 122.

(23) The torque sensor 112 and the further torque sensor 122 are operated independently of one another. The travel range optimization for the further compressor stage 12 is carried out in a manner corresponding to the above-described travel range optimization for the compressor stage 11.

Example 3

(24) The turbocompressor 1 is a geared compressor (FIG. 3). The compressor stage 11 and the further compressor stage 12 are connected to one another by way of a gearing mechanism 14. The rotary shaft 111 is driven by way of the motor 13. The further rotary shaft 12 is coupled to the rotary shaft 111 by way of the gearing mechanism 14.

(25) The torque of the rotary shaft 11 is measured by way of the torque sensor 112 and the further torque of the further rotary shaft 12 is measured by way of the further torque sensor 122.

(26) The fluid to be compressed is introduced into the geared compressor and the compressed fluid is removed from the geared compressor by way of the adjustable input control apparatus (ELA) 310 and the adjustable output control apparatus (ALA) 320, respectively.

(27) Further constituents are, once again, a volumetric flow rate metering orifice 330 and devices for measuring the pressure differences 340 and 350 at the individual compressor stages 11 and 12.