CN108397645B - Spring shock insulation foundation of turbo generator - Google Patents

Abstract

The invention discloses a spring shock insulation foundation of a steam turbine generator, which comprises the following components; the system comprises a turbine generator base bedplate, a main plant running layer platform, a turbine unit and a turbine base vibration damper. A steam turbine unit is arranged on the steam turbine generator basic bedplate; the steam turbine set comprises a plurality of cylinders; the cylinders are arranged along the main shaft of the turbine unit and are provided with a plurality of bearing seats; the bearing seat is taken as a center, the main shaft of the turbine unit is taken as a symmetrical shaft, and the vibration-reducing dampers of the turbine base are symmetrically arranged on two sides of the symmetrical shaft. The vibration isolation foundation can reduce the vibration of the foundation bedplate of the steam turbine generator and reduce the vibration of the base and the steam turbine generator.

Description

A spring isolation foundation for steam turbine generator

Technical Field

The invention relates to the field of mechanical engineering, and in particular to a spring isolation foundation for a steam turbine generator.

Background technique

The traditional spring isolation foundation of steam turbine generator only has springs in the vertical direction to play the role of seismic isolation, and the spring isolation foundation and the main powerhouse operation layer platform are prone to collision under the action of earthquakes or other horizontal loads. Under the action of earthquakes, the energy dissipation capacity of the traditional spring isolation steam turbine generator foundation is weak, and the seismic force transmitted to the steam turbine generator is large, while the seismic force that the steam turbine generator can withstand is limited. In high-intensity earthquake areas, the spring isolation steam turbine generator foundation is prone to produce large acceleration under the action of earthquakes.

Summary of the invention

The purpose of the present invention is to provide a spring isolation foundation for a steam turbine generator, so as to solve the problem that the energy dissipation capacity of the current spring isolation foundation for a steam turbine generator is relatively weak.

In the present invention, a spring isolation foundation for a steam turbine generator is provided, comprising: a steam turbine generator foundation plate, a main plant operation layer platform, a steam turbine unit and a steam turbine base vibration damper;

The steam turbine generator base plate is provided with the steam turbine unit;

The steam turbine unit comprises a plurality of cylinders;

The cylinders are arranged along the main axis of the steam turbine unit and are provided with a plurality of bearing seats; and

The bearing seat is taken as the center and the main axis of the steam turbine unit is taken as the symmetry axis, and the steam turbine base vibration dampers are symmetrically arranged on both sides of the symmetry axis.

In another preferred example, the steam turbine base vibration damper is located between the steam turbine generator foundation plate and the main plant operation layer platform, and the steam turbine base vibration damper is a horizontal vibration damper.

In another preferred example, the turbine base vibration damper is located on the straight line where the bearing seat is located.

In another preferred example, the turbine base vibration damper is located on both sides of the straight line where the bearing seat is located.

In another preferred example, the number of the turbine base vibration dampers located on both sides of the straight line is the same.

In another preferred embodiment, a gap is provided between the turbine base vibration dampers located on both sides of the straight line.

In another preferred embodiment, the seismic isolation foundation further includes a seismic damper;

The anti-vibration damper is located between the steam turbine generator foundation plate and the main plant operation layer platform; and

The vibration direction of the anti-vibration damper is perpendicular to the vibration direction of the turbine base vibration damper.

In another preferred embodiment, the seismic isolation foundation further includes a steam turbine generator foundation lower frame; and

The steam turbine generator foundation lower frame is located below the steam turbine generator foundation base plate and is connected to the steam turbine generator foundation base plate.

In another preferred example, a seismic isolation spring is provided between the lower frame of the steam turbine generator foundation and the steam turbine generator foundation plate.

In another preferred embodiment, the number of the bearing seats is 6-15, and the distance between the bearing seats is 1-10m.

It should be understood that within the scope of the present invention, the above-mentioned technical features of the present invention and the technical features specifically described below (such as embodiments) can be combined with each other to form a new or preferred technical solution. Due to space limitations, they will not be described one by one here.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of a spring isolation foundation of a steam turbine generator in one embodiment of the present invention.

FIG. 2 is a cross-sectional view of a spring isolation foundation of a steam turbine generator in one embodiment of the present invention.

Detailed ways

After extensive and in-depth research, the inventor has developed for the first time a spring seismic isolation foundation for a steam turbine generator. A horizontal damper is arranged between the foundation plate of the steam turbine generator and the platform structure of the operating layer of the main plant building, which can reduce the relative displacement between the foundation plate of the steam turbine generator and the floor slab of the main plant building under the action of horizontal loads. On this basis, the present invention was completed.

Seismic isolation foundation

The invention provides a spring seismic isolation foundation for a steam turbine generator, comprising a steam turbine generator foundation plate, a main plant operation layer platform, a steam turbine unit and a steam turbine base vibration reduction damper.

The steam turbine generator set is provided on the base plate of the steam turbine generator; the steam turbine set comprises a plurality of cylinders; the cylinders are arranged along the main axis of the steam turbine set and are provided with a plurality of bearing seats; and the steam turbine base vibration dampers are symmetrically arranged on both sides of the symmetry axis with the bearing seat as the center and the main axis of the steam turbine set as the symmetry axis.

The steam turbine base vibration damper is located between the steam turbine generator foundation plate and the main plant operation layer platform, and the steam turbine base vibration damper is a horizontal vibration damper. The type of the damper is not limited, and a viscous damper or a friction damper can be used. One end of the damper is connected to the longitudinal and transverse beams of the steam turbine generator foundation plate, and the other end is connected to the frame beam or column of the main plant operation layer platform. The connection method is to embed embedded parts on the foundation plate and the main plant frame beam, and the damper is welded to the embedded parts. When the main plant frame is a steel structure, it can be directly welded to the main plant frame steel structure.

Damper Arrangement Method

The unbalanced force of the rotor mass of a large steam turbine generator causes vibration of the rotor bearing and bearing seat. If the vibration is too large, it will cause the steam turbine generator to shut down, seriously affecting the operation of thermal power or nuclear power plants. By using a steam turbine generator spring vibration isolation foundation with a horizontal damper, the energy of the steam turbine unit vibration can be dissipated through the damper, thereby reducing the vibration of the rotor bearing seat and ensuring long-term safe and stable operation of the power plant.

The rotation of the turbine generator rotor can be simulated as the resonant force acting on the foundation. By establishing the dynamic equilibrium equation, the structural displacement solution can be divided into a steady-state part and a transient part.

The vibration differential equation of the steam turbine unit foundation with viscous damping under the action of harmonic force is:

Where:

u----is the displacement of the equipment support point, that is, the displacement of the bearing seat;

m----mass, including the weight of the foundation plate and the equipment and pipelines supported on the plate;

c----is the viscous damping coefficient;

k---- is the horizontal stiffness, that is, the total horizontal stiffness of the spring at the bottom of the spring isolation steam turbine generator foundation plate;

p0----is the exciting force, which is determined according to the balance quality grade of the steam turbine generator;

ω----is the exciting force frequency, that is, the rotation frequency of the steam turbine unit.

Its steady-state solution is:

Where:

ω _n ---- is the natural frequency of the base;

ξ---- is the damping ratio,

The structural damping ratio is increased by installing a damper between the operating layer platform and the turbine generator foundation plate to reduce the structural vibration displacement under steady-state load.

The damper provides damping through relative displacement, and the turbine generator foundation applies vibration loads to the equipment rotor through the turbine generator rotor unbalance level.

The disturbance force amplitude is shown as follows:

_Poi ^＝ _MgiGΩ2 /ω

Where:

P _oi - dynamic disturbance force;

M _gi - is the mass of the machine rotor acting on the i-th point of the foundation (disturbance point);

ω - the working speed of the machine;

Ω - Excitation speed during forced vibration analysis;

G - Balance quality grade. The balance quality grade is provided by the manufacturer and can be reduced by one level according to the dynamic balance grade of the rotor when it leaves the factory. It is expressed in mm/s.

The magnitude of the disturbance force is proportional to the mass of the machine rotor. Therefore, when arranging the horizontal damper, the damper setting should be proportional to the rotor mass to ensure that the relative displacement caused by the machine rotation is uniform and to avoid torsional deformation of the table due to unreasonable damper setting.

Taking the viscous damper as an example, the damping force generated by the viscous damper can be calculated by the following formula:

F＝cv ^α

Where:

F---damping force;

c---damping coefficient;

v---Relative velocity at both ends of the viscous damper;

α---speed index.

When setting the damper, the dynamic disturbance force value of the steam turbine generator unit can be compared with the damping force of the viscous damper. The disturbance force value at each bearing can be calculated to be equal to the damping force at the corresponding position, and the number of dampers required to be arranged at the corresponding position can be calculated, as shown in the following formula.

P _oi = nF _i

Where:

n----is the number of dampers set on both sides of each rotor bearing position.

Other types of dampers can also be calculated and arranged by the method that the damping force is equal to the dynamic disturbance force.

The main advantages of the present invention include:

(a) Horizontal dampers are installed between the steam turbine generator foundation plate and the main powerhouse operation layer platform structure to reduce the vibration of the steam turbine generator foundation plate, the vibration of the base and the steam turbine generator, dissipate energy, improve the seismic performance of the precision instruments on the plate, reduce the cross-sectional size of the equipment, and reduce the damage to the steam turbine generator on the plate under earthquake conditions, so that it can continue to operate safely and stably after an earthquake, provide emergency power to the society, and provide strong guarantee for social electricity use.

(b) Reduce equipment vibration and ensure safe and stable operation of the power plant.

(c) Promote the production of dampers, help improve the operating efficiency of steam turbine generators, and reduce repairs and maintenance.

The present invention will be further described below in conjunction with specific examples. It should be understood that these examples are intended only to illustrate the present invention and are not intended to limit the scope of the present invention. The experimental methods for the unrecorded specific conditions in the following examples are usually based on conventional conditions or the conditions recommended by the manufacturer. Unless otherwise stated, percentages and parts are weight percentages and weight parts.

It should be noted that in the claims and description of this patent, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "including one" do not exclude the existence of other identical elements in the process, method, article or device including the elements.

Example 1

As shown in FIG. 1 and FIG. 2 , this embodiment provides a steam turbine generator spring isolation foundation, comprising: a steam turbine generator foundation plate 1 , a main plant operation layer platform 2 , a steam turbine unit and a steam turbine base vibration damper 3 .

The steam turbine unit is arranged on the steam turbine generator base plate 1; the steam turbine unit includes a plurality of cylinders; the cylinders are arranged along the main axis of the steam turbine unit and are provided with a plurality of bearing seats; with the bearing seat as the center and the main axis of the steam turbine unit as the symmetry axis, the steam turbine base vibration damper 3 is symmetrically arranged on both sides of the symmetry axis.

In this embodiment, the steam turbine base vibration damper 3 is located between the steam turbine generator foundation plate 1 and the main plant operation layer platform 2, and the steam turbine base vibration damper 3 is a horizontal vibration damper 3, and the steam turbine base vibration damper 3 is located on the straight line where the bearing seat is located.

In this embodiment, the seismic isolation foundation also includes a seismic damper 4; the seismic damper 4 is located between the steam turbine generator foundation plate 1 and the main plant operation layer platform 2; the vibration direction of the seismic damper 4 is perpendicular to the vibration direction of the steam turbine base vibration damper 3.

The seismic isolation foundation further includes a steam turbine generator foundation lower frame 5 ; the steam turbine generator foundation lower frame 5 is located below the steam turbine generator foundation plate 1 and is connected to the steam turbine generator foundation plate 1 .

A seismic isolation spring 6 is provided between the steam turbine generator foundation lower frame 5 and the steam turbine generator foundation base plate 1 .

In this embodiment, the turbine base vibration damper adopts a viscous damper, and the vibration differential equation of the turbine unit foundation under the action of the resonant force is:

Where:

u----is the displacement of the equipment support point, that is, the displacement of the bearing seat;

m----mass, including the weight of the foundation plate and the equipment and pipelines supported on the plate;

c----is the viscous damping coefficient;

k---- is the horizontal stiffness, that is, the total horizontal stiffness of the spring at the bottom of the spring isolation steam turbine generator foundation plate;

p0----is the exciting force, which is determined according to the balance quality grade of the steam turbine generator;

ω----is the exciting force frequency, that is, the rotation frequency of the steam turbine unit.

Its steady-state solution is:

Where:

ω _n ---- is the natural frequency of the base;

ξ---- is the damping ratio,

The structural damping ratio is increased by installing a damper between the operating layer platform and the turbine generator foundation plate to reduce the structural vibration displacement under steady-state load.

The damper provides damping through relative displacement, and the turbine generator foundation applies vibration loads to the equipment rotor through the turbine generator rotor unbalance level.

The disturbance force amplitude is shown as follows:

_Poi ^＝ _MgiGΩ2 /ω

Where:

P _oi - dynamic disturbance force;

M _gi - is the mass of the machine rotor acting on the i-th point of the foundation (disturbance point);

ω - the working speed of the machine;

Ω - Excitation speed during forced vibration analysis;

G - Balance quality grade. The balance quality grade is provided by the manufacturer and can be reduced by one level according to the dynamic balance grade of the rotor when it leaves the factory. It is expressed in mm/s.

The magnitude of the disturbance force is proportional to the mass of the machine rotor. Therefore, when arranging the horizontal damper, the damper setting should be proportional to the rotor mass to make the relative displacement caused by the machine rotation uniform and avoid torsional deformation of the table due to unreasonable damper setting.

Taking the viscous damper as an example, the damping force generated by the viscous damper can be calculated by the following formula:

F＝cv ^α

Where:

F---damping force;

c---damping coefficient;

v---Relative velocity at both ends of the viscous damper;

α---speed index.

When setting the damper, the dynamic disturbance force value of the steam turbine generator unit can be compared with the damping force of the viscous damper. The disturbance force value at each bearing can be calculated to be equal to the damping force at the corresponding position, and the number of dampers required to be arranged at the corresponding position can be calculated, as shown in the following formula.

P _oi = nF _i

Where:

n----is the number of dampers set on both sides of each rotor bearing position.

Relevant technicians arranged the corresponding turbine base vibration damper and anti-vibration damper by the above-mentioned isolation foundation and damper arrangement method, and calculated the vibration reduction effect of the isolation foundation as follows:

The lateral vibration line displacement of each bearing seat of the turbine base under the dynamic disturbance force of the turbine generator is reduced by 20%-30% compared with the case without horizontal damper.

Comparative Example 1

Comparative Example 1 provides a steam turbine generator spring isolation foundation similar to that of Example 1, except that the turbine base vibration damper in Comparative Example 1 is arranged on both sides between two adjacent bearing seats with the main axis of the steam turbine unit as the axis of symmetry.

Relevant technicians arranged the corresponding turbine base vibration damper and anti-vibration damper by the above-mentioned isolation foundation and damper arrangement method, and calculated the vibration reduction effect of the isolation foundation as follows:

The lateral vibration line displacement of each bearing seat of the turbine base under the dynamic disturbance force of the turbine generator is reduced by 5%-10% compared with the case without horizontal damper.

By comparing Example 1 and Comparative Example 1, it can be found that the seismic isolation foundation of Example 1 has lower cost, and the vibration reduction effect is improved by 10%-25%, and the vibration reduction effect is better.

Example 2

This embodiment provides a spring isolation foundation for a steam turbine generator. The isolation foundation in this embodiment is similar to the isolation foundation in Embodiment 1, except that:

In this embodiment, the turbine base vibration dampers are located on both sides of the straight line where the bearing seat is located, the number of the turbine base vibration dampers located on both sides of the straight line is the same, and a gap is provided between the turbine base vibration dampers located on both sides of the straight line;

The number of the bearing seats is 10, and the distance between the bearing seats is 5m.

All documents mentioned in the present invention are cited as references in this application, just as each document is cited as references individually. In addition, it should be understood that after reading the above teachings of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the claims attached to this application.

Claims (4)

1. A turbo generator spring shock insulation foundation for a large steam turbine, comprising; a turbine generator base bedplate (1), a main plant running layer platform (2), a turbine unit and a turbine base vibration damper (3);

The steam turbine generator basic bedplate (1) is provided with the steam turbine unit;

the steam turbine unit comprises a plurality of cylinders;

The cylinders are arranged along the main shaft of the turbine unit and are provided with a plurality of bearing seats; and

The main shaft of the turbine unit is taken as a symmetrical shaft, the turbine base vibration dampers (3) are symmetrically arranged on two sides of the symmetrical shaft, the turbine base vibration dampers (3) are positioned between the turbine generator base bedplate (1) and the main plant operation layer platform (2), so that the structural damping ratio is increased to reduce structural vibration displacement acted by steady load, the turbine base vibration dampers (3) are horizontal vibration dampers, the turbine base vibration dampers (3) are positioned on a straight line where the bearing seat is positioned or on two sides of the straight line where the bearing seat is positioned, one end of each damper is connected with a turbine generator base bedplate longitudinal and transverse beam, and the other end of each damper is connected with a main plant operation layer platform frame beam or column;

the shock insulation foundation also comprises a shock-proof damper (4);

The shockproof damper (4) is positioned between the steam turbine generator base bedplate (1) and the main plant operation layer platform (2); and

The vibration direction of the vibration-proof damper (4) is perpendicular to the vibration direction of the vibration-proof damper (3) of the turbine base;

The shock insulation foundation also comprises a steam turbine generator foundation lower frame (5); and

The steam turbine generator foundation lower frame (5) is positioned below the steam turbine generator foundation bedplate (1) and connected with the steam turbine generator foundation bedplate (1), and a shock insulation spring (6) is arranged between the steam turbine generator foundation lower frame (5) and the steam turbine generator foundation bedplate (1);

The damping damper of the steam turbine base adopts a viscous damper,

The disturbance force amplitude is shown in the following formula:

P_oi＝M_giGΩ²/ω

Wherein:

P _oi -dynamic disturbance force;

M _gi -is the mass of the machine rotor acting at the base ith point (disturbance force point);

Operating speed of omega-machine;

exciting rotation speed during omega-forced vibration analysis;

g-balancing quality grade, wherein the balancing quality grade is provided by a manufacturer, and can be reduced by one step according to the factory dynamic balancing grade of the rotor by mm/s;

The disturbing force is in direct proportion to the rotor mass of the machine, and when the horizontal damper is arranged, the damper is arranged in direct proportion to the rotor mass, so that the relative displacement generated by the rotation of the machine is uniform, and the torsional deformation of the bedplate caused by unreasonable damper arrangement is avoided;

The damping force generated by a viscous damper can be calculated by the following formula:

F＝cv^α

Wherein:

F, damping force;

c- -damping coefficient;

v—relative speed at both ends of viscous damper;

Alpha- - -a velocity index;

when the dampers are arranged, the dynamic disturbance force value of the turbo generator unit and the damping force of the viscous damper can be calculated in a comparison mode, the disturbance force value is calculated at each bearing to be equal to the damping force at the corresponding position, and the number of the dampers to be arranged at the corresponding position is calculated, wherein the number is shown in the following formula:

P_oi＝nF_i

Wherein:

n-is the number of dampers arranged on both sides of each rotor bearing position.

2. The shock insulation foundation of claim 1 wherein the number of said turbine base vibration damping dampers on either side of said straight line is the same.

3. The shock insulation foundation of claim 1 wherein a gap is provided between said turbine base vibration damping dampers on either side of said straight line.

4. The shock insulation foundation of claim 1, wherein the number of bearing blocks is 6-15 and the distance between the bearing blocks is 1-10m.