CN115949469A - Thrust self-balancing system and monitoring method for supercritical carbon dioxide turbine - Google Patents

Abstract

The invention relates to the technical field of turbines, in particular to a thrust self-balancing system and a monitoring method of a supercritical carbon dioxide turbine, and the thrust self-balancing system comprises a turbine end, a balancing end, a high-speed generator, a main shaft, a casing and a monitoring component, wherein the main shaft provides installation conditions for the high-speed generator, the balancing end is used for balancing the thrust of the turbine, the high-speed generator is used for outputting power, the monitoring component is used for monitoring the thrust of a turbine shaft system, the system monitors the pressure of the turbine shaft system through the monitoring component, calculates and judges whether the thrust difference of the shaft system is larger than the capacity of a thrust bearing, if the thrust difference is larger than the capacity of the thrust bearing, a shutdown signal is sent, if the thrust difference is smaller than or equal to the capacity of the thrust bearing, the thrust under all working conditions is not over capacity, and the problem that the axial thrust generated by the existing single-suspension turbine is far larger than the maximum capacity of the thrust bearing is solved.

Description

Thrust self-balancing system and monitoring method for supercritical carbon dioxide turbine

Technical Field

The invention relates to the technical field of turbines, in particular to a thrust self-balancing system and a monitoring method of a supercritical carbon dioxide turbine.

Background

The closed cycle power system using the supercritical carbon dioxide as the working medium can greatly reduce the size of equipment such as a turbine, a compressor and the like, has the advantages of high energy density, low compression power consumption, no phase change in cycle, low initial investment and low operation cost, and is considered as the best scheme of a future power system.

The supercritical carbon dioxide turbine is an important part for converting heat energy into mechanical energy in a thermal circulation system, generally adopts a single-cantilever turbine, then adopts a direct-drive high-speed generator, or drives a common generator to generate power through a coupling after being decelerated by a gearbox, can reduce the heat load of a unit and reduce the aerodynamic loss caused by an interstage pipeline compared with a double-cantilever turbine, and at present, the supercritical carbon dioxide turbine mainly adopts an oil film bearing, and the linear velocity of the oil film bearing has a limit value, so that the capacity of a thrust bearing has a maximum value, and the axial thrust generated by the single-cantilever turbine is far greater than the maximum capacity of the thrust bearing.

Disclosure of Invention

The invention aims to provide a thrust self-balancing system and a monitoring method of a supercritical carbon dioxide turbine, and aims to solve the problem that the axial thrust generated by the conventional single-suspension turbine is far larger than the maximum capacity of a thrust bearing.

In order to achieve the above object, in a first aspect, the present invention provides a thrust self-balancing system for a supercritical carbon dioxide turbine, including a turbine end, a balancing end, a high-speed generator, a main shaft, a casing, and a monitoring assembly, where the high-speed generator is disposed in the casing, the main shaft is rotatably connected to the high-speed generator and penetrates through the high-speed generator, the turbine end is disposed on one side of the main shaft, the balancing end is disposed on the other side of the main shaft, and the monitoring assembly is disposed outside the casing.

Wherein, the control assembly includes changer group, incoming signal line, PLC control module and output signal line, the changer group set up in the machine casket outside, the incoming signal line with changer group electricity is connected, and with PLC control module electricity is connected, and is located PLC control module with between the changer group, the output signal line with PLC control module electricity is connected.

The turbine end comprises a nozzle ring set, a turbine disc set, a pull rod screw, a labyrinth seal and a turbine end dry gas seal dynamic and static ring set, the turbine disc set is arranged on one side of the main shaft, the pull rod screw is fixedly connected with the main shaft and penetrates through the turbine disc set, the nozzle ring set is arranged on the outer side of the turbine disc set, the labyrinth seal is arranged on one side of the main shaft close to the nozzle ring set, and the turbine end dry gas seal dynamic and static ring set is arranged on one side of the nozzle ring set away from the labyrinth seal.

The balance end comprises a balance end dry gas sealing movable ring and a balance end dry gas sealing static ring, the balance end dry gas sealing movable ring is arranged on one side, away from the main shaft, of the vortex end dry gas sealing movable ring group, the balance end dry gas sealing static ring is arranged in the casing, attached to the balance end dry gas sealing movable ring and located on one side, away from the main shaft.

In a first aspect, the present invention further provides a thrust self-balancing monitoring method for a supercritical carbon dioxide turbine, including the following steps:

monitoring a pressure value of a turbine shafting through a monitoring component to obtain initial monitoring data;

the monitoring component calculates and differentiates the initial monitoring data based on a built-in program to obtain the difference of the thrust;

and judging whether the thrust difference is greater than the thrust bearing capacity, if so, sending a shutdown signal, and if not, operating.

According to the thrust self-balancing system of the supercritical carbon dioxide turbine, a main shaft is connected with a high-speed generator (gear box) through a bearing, penetrates through the high-speed generator and extends into a turbine end and a balance end, the main shaft can freely rotate in the high-speed generator (gear box), the balance end is used for balancing the thrust of the turbine, the high-speed generator is used for outputting power, a monitoring component is used for monitoring the thrust of a turbine shafting, the system monitors the pressure of the turbine shafting through the monitoring component, calculates and judges whether the thrust difference of the thrust shafting is greater than the capacity of a thrust bearing, sends a shutdown signal if the thrust difference is greater than the capacity of the thrust bearing, and operates if the thrust difference is less than or equal to the capacity of the thrust bearing, so that the thrust under all working conditions is not over capacity, and the problem that the axial thrust generated by the existing single-suspension type turbine is far greater than the maximum capacity of the thrust bearing is solved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a thrust self-balancing system of a supercritical carbon dioxide turbine provided by the invention.

FIG. 2 is a schematic view of the connection of monitoring components of a thrust self-balancing system of a supercritical carbon dioxide turbine provided by the invention.

Fig. 3 is a flow chart of a thrust self-balancing monitoring method for a supercritical carbon dioxide turbine provided by the invention.

The system comprises a gas inlet pipe 1, a gas inlet pipe 2, a fourth pressure transmitter 2, a first-stage nozzle ring 3, a second-stage nozzle ring 4, a third-stage nozzle ring 5, a casing 6, a fourth-stage nozzle ring 7, a third pressure transmitter 8, a gas outlet pipe 9, a labyrinth seal 10, a second pressure transmitter 11, a balance pipe 12, a flowmeter 13, a signal line 14, a regulating valve 15, a pipeline 16, a dry gas seal gas source 17, a first pressure transmitter 18, a main shaft 19, a dry gas seal dynamic ring 20, a dry gas seal static ring 21, a dry gas seal static ring 22, a dry gas seal dynamic ring 23, a dry gas seal dynamic ring 24, a third-stage turbine disc 25, a second-stage turbine disc 26, a first-stage turbine disc 27, a pull rod screw 28, an exhaust cavity 29, a dry gas seal cavity 30, a dry gas seal cavity 31, a balance cavity 32, an input signal line 33, a PLC control module 34 and an output signal line 34.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

In a first aspect, referring to fig. 1 to fig. 3, the present invention provides a thrust self-balancing system for a supercritical carbon dioxide turbine, including a turbine end, a balancing end, a high-speed generator, a main shaft 19, a casing 6, and a monitoring assembly, where the high-speed generator is disposed in the casing 6, the main shaft 19 is rotatably connected with the high-speed generator and penetrates through the high-speed generator, the turbine end is disposed on one side of the main shaft 19, the balancing end is disposed on the other side of the main shaft 19, and the monitoring assembly is disposed outside the casing 6.

Specifically, main shaft 19 with high-speed generator (gear box) links to each other through the bearing, passes high-speed generator stretches into turbine end with balanced end, main shaft 19 is in but free rotation in high-speed generator (gear box), balanced end is used for balanced turbine thrust, high-speed generator is used for output, the control subassembly is used for monitoring turbine shafting thrust, and this system passes through the control subassembly monitors turbine shafting pressure to whether the calculation judges shafting thrust difference is greater than thrust bearing capacity, then send shutdown signal, then the operation is carried out to less than or equal to, can realize not the excess capacity at all operating mode thrusts, and the axial thrust of solving current singly hanging turbine production is greater than the problem of thrust bearing capacity.

Further, the monitoring component includes transmitter group, input signal line 32, PLC control module 33 and output signal line 34, the transmitter group set up in the 6 outsides of machine casket, input signal line 32 with transmitter group electricity is connected, and with PLC control module 33 electricity is connected, and is located PLC control module 33 with between the transmitter group, output signal line 34 with PLC control module 33 electricity is connected.

Specifically, the pressure of the vortex-end dry gas seal cavity 30 is measured by the second pressure transmitter 11, the pressure value is P2, the supercritical carbon dioxide enters the turbine from the gas inlet pipe 1, the gas inlet pressure is measured by the fourth pressure transmitter 2, the pressure value is P4, the supercritical carbon dioxide enters the exhaust cavity 29 after acting through the nozzle ring group and the turbine disc group, and then is discharged from the exhaust pipeline 9, the exhaust pressure is measured by the third pressure transmitter 8, the pressure value is P3, and the difference between the pressure of the exhaust cavity 29 and the exhaust pressure P3 is small, so that the pressure value and the pressure value are considered to be equal.

Further, the turbine end includes nozzle ring group, turbine disk group, pull rod screw 28, labyrinth seal 10 and the sealed sound ring group of whirlpool end dry gas, turbine disk group sets up in 19 one side of main shaft, pull rod screw 28 with 19 fixed connection of main shaft, and run through the turbine disk group, nozzle ring group set up in the turbine disk group outside, labyrinth seal 10 set up in 19 of main shaft is close to nozzle ring group one side, the sealed sound ring group of whirlpool end dry gas set up in labyrinth seal 10 keeps away from nozzle ring group one side.

Specifically, the nozzle ring group with the turbine disc group is the permutation installation, the nozzle ring group includes one-level nozzle ring 3, second grade nozzle ring 4, tertiary nozzle ring 5 and level four nozzle ring 7, and installs in proper order in the machine casket 6, through the pull rod screw 28 will the turbine disc group includes that one-level turbine disc 27, second grade turbine disc 26, tertiary turbine disc 25 and level four turbine disc 24 arrange in proper order and install on the main shaft 19, labyrinth seal 10 is installed in the machine casket 6, be located exhaust chamber 29 behind one's back, vortex end dry gas seal movable ring 23 is installed behind labyrinth seal 10 back, vortex end dry gas seal quiet ring 22 is installed in the machine casket 6, with the little clearance laminating of vortex end dry gas seal movable ring 23, and form vortex end dry gas seal chamber 30 between the labyrinth seal 10.

Further, the balance end comprises a balance end dry gas sealing movable ring 20 and a balance end dry gas sealing static ring 21, the balance end dry gas sealing movable ring 20 is arranged on one side, away from the main shaft 19, of the vortex end dry gas sealing movable ring group, the balance end dry gas sealing static ring 21 is arranged in the casing 6, attached to the balance end dry gas sealing movable ring 20 and located on one side, away from the main shaft 19.

Specifically, a balance end dry gas seal dynamic ring 20 is installed at the shaft end of the main shaft 19, and a balance end dry gas seal static ring 21 is installed in the casing 6 to form a balance cavity 31, the pressure of the balance cavity is measured by the first pressure transmitter 18, and the pressure value is P1.

The dry gas sealing air source 17 is from a power generation system and is connected with the balance cavity 31 through a pipeline 16, the balance cavity 31 is connected with the vortex end dry gas sealing cavity 30 through a balance pipe 12, the balance pipe 12 is provided with an adjusting valve 15, the opening degree of the adjusting valve is subjected to feedback control through a signal line 14 by the flowmeter 13, and the flowmeter 13 is ensured to be a set value all the time.

The seal gas by dry gas seal air supply 17, process the pipeline 16 flow direction balance chamber 31, produce thrust, pass through balance pipe 12, process the governing valve 15 is adjusted the back and is injected into vortex end dry gas seal chamber 30, later as cooling gas, flow through labyrinth seal 10, the cooling the machine casket 6 with main shaft 19 injects the exhaust chamber 29 at last, converges the mainstream and discharges, and two dry gas seal points use a seal gas, have reduced the seal gas quantity, improve system's generating efficiency.

Setting the pressure-bearing area of the balance cavity 31 as A1, measuring a pressure value P1 by the first pressure transmitter 18, setting the thrust of the balance end as F1= A1 × P1, and pointing to the turbine end; the pressure-bearing area A2 of the vortex end dry gas seal cavity 30, the pressure value P2 of which is measured by the second pressure transmitter 11, the thrust is F2= A2 × P2, and the direction points to the balance end; the thrust generated by aerodynamic force and interstage pressure difference on the turbine disc group is F3, the direction is directed to the balance end, the F3 is related to the intake pressure P4 and the exhaust pressure P3, the P4 is measured by the fourth pressure transmitter 2, the P3 is measured by the third pressure transmitter 8, and each determined intake pressure P4 and exhaust pressure P3 can be determined into F3 through the pneumatic simulation calculation of the through-flow part.

The dry gas sealing gas source 17 is a gas which comes from a high-pressure storage tank at the outlet of a compressor in a power generation system and is heated and filtered, the pressure P1 of the balance cavity 31 is equal to the pressure of the outlet of the compressor minus the loss of a sealing pipeline, the pressure P4 of the inlet of a turbine in the supercritical carbon dioxide power generation system is equal to the pressure of the outlet of the compressor minus the loss of a main pipeline, according to experience, the changes of P1 and P4 are consistent and the difference value is not large, and for a unit with the power of less than 1000kW and with the pressure of-1 MPa being not more than P1-P4 being not more than 1MPa; because the cooling flow required by the turbine end is constant, namely the value of the flowmeter 13 is unchanged, the pressure P2 of the dry gas seal cavity 30 at the turbine end is greater than the exhaust pressure P3, changes along with the change of P3 and is not greater than P1, namely P3 is greater than or equal to P2 and is less than or equal to P1.

Considering values of inlet and outlet pressures P4 and P3 of the turbine under different working conditions, which may occur in the operation process, so as to determine F3 in a simulation manner; the equilibrium cavity pressure P1= P4+ k (k is more than or equal to 1MPa according to the experience-1 MPa), an upper limit and a lower limit exist, and if A1 is determined, the upper limit and the lower limit exist in F1; the pressure P2 of the vortex end dry gas seal cavity is more than or equal to P3 and P2 is less than or equal to P1, upper and lower limits exist, and if A2 is determined, upper and lower limits exist on F2; for each group of determined P4 and P3, the upper and lower limits of P1 and P2 can be obtained, so that the upper and lower limits of F1 and F2 are obtained; therefore, the resultant force of F1, F2 and F3, namely the upper and lower limits of the thrust of the shafting can be obtained for each working condition, and the upper and lower limits of the thrust value of the shafting are within the range of the bearing capacity under various working conditions through calculation.

In a second aspect, referring to fig. 3, the present invention provides a thrust self-balancing monitoring method for a supercritical carbon dioxide turbine, including the following steps:

s1, monitoring a pressure value of a turbine shafting through a monitoring component to obtain initial monitoring data;

specifically, the pressure value of the shafting is monitored through the PLC monitoring component, and is transmitted into the PLC control module through the input signal line 32.

S2, the monitoring component calculates the difference of the initial monitoring data based on a built-in program to obtain the difference of the thrust;

specifically, the measured balance cavity pressure P1 and the vortex end dry gas seal cavity pressure P2 are input to the PLC control module through the input signal line 32, the balance end thrust F1 and the vortex end dry gas seal thrust F2 can be calculated through a built-in program of the PLC control module, the measured turbine intake pressure P4 and the exhaust pressure P3 are input to the PLC control module, the vortex end thrust F3 can be obtained through the built-in program, and the absolute value | F1-F2-F3| of the thrust difference, that is, the thrust difference is calculated.

And S3, judging whether the thrust difference is greater than the thrust bearing capacity, if so, sending a shutdown signal, and if not, operating.

Specifically, the PLC control module judges whether the thrust bearing capacity FT less than or equal to | F1-F2-F3| is satisfied, if so, the PLC control module continues to operate, otherwise, the PLC control module sends a shutdown signal through the output signal line 34 _。

While the above disclosure describes the preferred embodiment of the present invention, it is understood that the scope of the present invention is not limited thereto, and that all or part of the process flow of the above embodiment may be implemented by those skilled in the art, and all equivalent changes and modifications made by the appended claims are intended to be covered by the present invention.

Claims (5)

1. A thrust self-balancing system of a supercritical carbon dioxide turbine is characterized in that,

including turbine end, balanced end, high speed generator, main shaft, machine casket and control subassembly, high speed generator set up in the machine casket, the main shaft with high speed generator rotates to be connected to run through high speed generator, the turbine end set up in main shaft one side, balanced end set up in the main shaft opposite side, the control subassembly set up in the machine casket outside.

2. The thrust self-balancing system of a supercritical carbon dioxide turbine as claimed in claim 1,

the monitoring component comprises a transmitter group, an input signal line, a PLC control module and an output signal line, the transmitter group is arranged on the outer side of the casing, the input signal line is electrically connected with the transmitter group and electrically connected with the PLC control module, the PLC control module is located between the PLC control module and the transmitter group, and the output signal line is electrically connected with the PLC control module.

3. The thrust self-balancing system and monitoring method of supercritical carbon dioxide turbine as claimed in claim 1,

the turbine end comprises a nozzle ring set, a turbine disc set, a pull rod screw, a labyrinth seal and a turbine end dry gas seal dynamic and static ring set, the turbine disc set is arranged on one side of the main shaft, the pull rod screw is fixedly connected with the main shaft and penetrates through the turbine disc set, the nozzle ring set is arranged on the outer side of the turbine disc set, the labyrinth seal is arranged on one side, close to the main shaft, of the nozzle ring set, and the turbine end dry gas seal dynamic and static ring set is arranged on one side, far away from the nozzle ring set, of the labyrinth seal.

4. The system and method for self-balancing thrust of supercritical carbon dioxide turbines as claimed in claim 3,

the balanced end includes balanced end dry gas seal rotating ring and balanced end dry gas seal quiet ring, balanced end dry gas seal rotating ring set up in the main shaft is kept away from one side of the sealed rotating ring group of whirlpool end dry gas, balanced end dry gas seal quiet ring set up in the machine casket, and with the laminating of balanced end dry gas seal rotating ring, and be located and keep away from main shaft one side.

5. A thrust self-balancing monitoring method of a supercritical carbon dioxide turbine is applied to the thrust self-balancing system and the monitoring method of the supercritical carbon dioxide turbine as claimed in claim 1, and is characterized by comprising the following steps:

monitoring a pressure value of a turbine shafting through a monitoring component to obtain initial monitoring data;

the monitoring component calculates the difference of the initial monitoring data based on a built-in program to obtain the difference of the thrust;

and judging whether the thrust difference is greater than the thrust bearing capacity, if so, sending a shutdown signal, and if not, operating.

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