阅读说明：本技术 汽轮机空负荷试验外部热膨胀位移检测方法 (Method for detecting external thermal expansion displacement in steam turbine air load test ) 是由 张弛 郭璨 马德鹏 庄乾才 陈伟韬 吕会颖 于 2020-11-25 设计创作，主要内容包括：汽轮机空负荷试验外部热膨胀位移检测方法,属于汽轮机检测技术领域。解决了在对汽轮机进行热膨胀位移检测时存在检测成本高和检测周期长的问题。本发明据汽轮机空负荷试验外部热膨胀检测位置绘制测点布置图；根据测点布置图布置测量仪表；对所有测量仪表进行调零；记录测量仪表的初始状态；汽轮机进行空负荷实验,获取测量仪表的测量读数,完成检测。本发明适用于汽轮机空负荷试验外部热膨胀位移检测。(A method for detecting external thermal expansion displacement in a turbine air load test belongs to the technical field of turbine detection. The problem of have the detection cost height and detect the cycle length when carrying out the thermal expansion displacement detection to the steam turbine is solved. According to the invention, a measuring point layout diagram is drawn according to the external thermal expansion detection position of the steam turbine air load test; arranging measuring instruments according to the measuring point arrangement diagram; zeroing all measuring instruments; recording the initial state of the measuring instrument; and (4) carrying out an air load experiment on the steam turbine, obtaining the measurement reading of the measuring instrument, and completing the detection. The invention is suitable for detecting the external thermal expansion displacement in the steam turbine air load test.)

1. The method for detecting the external thermal expansion displacement in the steam turbine air load test is characterized by comprising the following steps of:

step one, drawing a measuring point layout according to an external thermal expansion detection position of a steam turbine air load test;

step two, arranging measuring instruments according to the measuring point arrangement diagram;

step three, zeroing all the measuring instruments; recording the initial state of the measuring instrument;

step four, carrying out an air load experiment on the steam turbine, obtaining the measurement reading of the measuring instrument, and completing detection;

wherein, the time for obtaining the measurement reading of the measuring instrument is as follows: after the turbine is preheated for 20min, before the turbine is started, when the turbine reaches the highest rated rotating speed, before the turbine is stopped, the turbine is stopped and turned for 15min, and after the turbine is completely cooled and stopped and turned.

2. The method for detecting the external thermal expansion displacement in the air load test of the steam turbine according to claim 1, wherein the positions of the measuring points in the first step are as follows:

two measuring points are arranged at the intersection of the extension lines of the central lines of the front bearing and the rear bearing of the front bearing seat of the steam turbine and the mid-plane; two measuring points are arranged at the intersection of the central line extension lines of the front bearing and the rear bearing of the rear bearing seat of the steam turbine and the mid-plane; two axial measuring points and two radial measuring points are symmetrically arranged on the left side and the right side of the end surface of the front end of the bedplate at the front part of the steam turbine cylinder; two axial measuring points and two radial measuring points are symmetrically arranged on the left side and the right side of the end surface of the rear end of the bedplate at the rear part of the steam turbine cylinder.

3. The method for detecting the external thermal expansion displacement in the steam turbine air load test according to claim 1 or 2, wherein the specific manner of arranging the measuring instruments according to the measuring point arrangement diagram in the second step is as follows: the device comprises a support and a magnetic base, wherein the support is fixed on a base of a steam turbine, the support is used for fixing the magnetic base, a measuring instrument is installed on the magnetic base, and a pointer of the measuring instrument points to a measuring point.

Technical Field

The invention belongs to the technical field of steam turbine detection.

Background

After the steam turbine is manufactured, an air load performance verification test is required before the steam turbine leaves a factory. During the air load test, the thermal expansion displacement detection is carried out on the external structure (an outer cylinder, a base frame and the like) of the steam turbine, whether the design requirements of the starting and the test of the steam turbine are met or not is confirmed, and the safety and the stability of the steam turbine test are ensured.

The thermal expansion displacement of the steam turbine usually uses a displacement sensor and a matched data acquisition device to carry out data detection and acquisition, each measuring point needs to be provided with the displacement sensor, a measuring line and a data acquisition box, in addition, special data detection and acquisition software is needed, the manufacturing cost and the storage and maintenance cost are high, and the air load test cost of the steam turbine is increased. When the steam turbines of different models are measured, the measuring equipment and the measuring channel need to be rearranged, and the arrangement period is long.

Disclosure of Invention

The invention provides a method for detecting external thermal expansion displacement in a turbine air load test, which aims to solve the problems of high detection cost and long detection period when the thermal expansion displacement is detected in a turbine.

The invention relates to a method for detecting external thermal expansion displacement in a steam turbine air load test, which specifically comprises the following steps:

step one, drawing a measuring point layout according to an external thermal expansion detection position of a steam turbine air load test;

step two, arranging measuring instruments according to the measuring point arrangement diagram;

step three, zeroing all the measuring instruments; recording the initial state of the measuring instrument;

step four, carrying out an air load experiment on the steam turbine, obtaining the measurement reading of the measuring instrument, and completing detection;

wherein, the time for obtaining the measurement reading of the measuring instrument is as follows: after the turbine is preheated for 20min, before the turbine is started, when the turbine reaches the highest rated rotating speed, before the turbine is stopped, the turbine is stopped and turned for 15min, and after the turbine is completely cooled and stopped and turned.

The positions of the measuring points in the first step are as follows:

furthermore, two measuring points are arranged at the intersection of the extension lines of the central lines of the front bearing and the rear bearing of the front bearing seat of the steam turbine and the median plane; two measuring points are arranged at the intersection of the central line extension lines of the front bearing and the rear bearing of the rear bearing seat of the steam turbine and the mid-plane; two axial measuring points and two radial measuring points are symmetrically arranged on the left side and the right side of the end surface of the front end of the bedplate at the front part of the steam turbine cylinder; two axial measuring points and two radial measuring points are symmetrically arranged on the left side and the right side of the end surface of the rear end of the bedplate at the rear part of the steam turbine cylinder.

Further, the specific way of arranging the measuring instruments according to the measuring point arrangement diagram in the step two is as follows: the device comprises a support and a magnetic base, wherein the support is fixed on a base of a steam turbine, the support is used for fixing the magnetic base, a measuring instrument is arranged on the magnetic base, and a pointer of the measuring instrument points to a measuring point.

The method of the invention adopts a conventional measuring tool to carry out data detection, thereby reducing the detection cost; the measuring point arrangement, data detection and acquisition processes are technically standardized, and the accuracy of detected data is ensured; the detection mode is convenient to arrange, and the test installation period is shortened. The detection method is suitable for factory air load verification tests of various turbines.

Drawings

FIG. 1 is a side view of a turbine station arrangement according to the present invention;

FIG. 2 is a top view of a turbine station arrangement according to the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

The first embodiment is as follows: the following describes the present embodiment with reference to fig. 1 and fig. 2, and the method for detecting external thermal expansion displacement in the steam turbine air load test according to the present embodiment specifically includes:

step one, drawing a measuring point layout according to an external thermal expansion detection position of a steam turbine air load test;

step two, arranging measuring instruments according to the measuring point arrangement diagram;

step three, zeroing all the measuring instruments; recording the initial state of the measuring instrument;

step four, carrying out an air load experiment on the steam turbine, obtaining the measurement reading of the measuring instrument, and completing detection;

wherein, the time for obtaining the measurement reading of the measuring instrument is as follows: after the turbine is preheated for 20min, before the turbine is started, when the turbine reaches the highest rated rotating speed, before the turbine is stopped, the turbine is stopped and turned for 15min, and after the turbine is completely cooled and stopped and turned.

In the embodiment, the measurement after the turbine is preheated for 20 minutes can obtain the rising stage data of the thermal expansion displacement when the turbine does not operate, the measurement before the turbine is started can obtain the rising stage data of the thermal expansion displacement when the turbine does not operate, the measurement when the turbine reaches the highest rated rotating speed can obtain the maximum data of the thermal expansion displacement under the turbine operating state, the measurement before the turbine stops can obtain the falling stage data of the thermal expansion displacement under the turbine operating state, the measurement after the turbine stops and turns for 15min can obtain the falling stage data of the thermal expansion displacement after the turbine operates and stops, and the measurement after the turbine is completely cooled can confirm whether the thermal expansion displacement data of the turbine recovers to the initial state. Through the measurement of the nodes, the thermal expansion displacement data of the turbine from the initial stage to each key stage of preheating, running, stopping and cooling can be effectively obtained, and effective data support is provided for drawing a thermal expansion displacement curve of the turbine and technical analysis.

Further, as shown in fig. 1 and fig. 2, two measuring points (measuring point 1 and measuring point 2) are arranged at the intersection of the extension lines of the central lines of the front bearing and the rear bearing of the front bearing seat of the steam turbine and the bisection plane; two measuring points (measuring point 3 and measuring point 4) are arranged at the intersection of the central line extension lines of the front bearing and the rear bearing of the turbine rear bearing seat and the mid-plane; two axial measuring points (measuring point 5 and measuring point 7) and two radial measuring points (measuring point 6 and measuring point 8) are symmetrically arranged on the left side and the right side of the front end face of the bedplate at the front part of the steam turbine cylinder; two axial measuring points (measuring points 9 and 11) and two radial measuring points (measuring points 10 and 12) are symmetrically arranged on the left side and the right side of the rear end face of the bedplate at the rear part of the steam turbine cylinder.

The two measuring points at the two intersection points of the front and rear bearing center line extension lines of the front bearing seat and the middle facet of the steam turbine and the two measuring points at the two intersection points of the front and rear bearing center line extension lines of the rear bearing seat and the middle facet of the steam turbine can effectively measure the elevation change of the steam turbine bearing. Two axial measuring points are symmetrically arranged on the left side and the right side of the end surface (vertical to the center line of the steam turbine) of the front end of the bedplate of the steam turbine cylinder, and two radial measuring points are symmetrically arranged on the end surfaces (parallel to the center line of the steam turbine) of the two sides; the measuring points are also arranged on the end surface of the bedplate at the rear part of the steam turbine cylinder according to the mode, and the total number is 8. The 8 measuring points can effectively measure displacement changes of the steam turbine cylinder in four directions, namely front, back, left and right.

In the invention, before measurement, an inspector zeroes all the pointers of the dial indicators and records the initial state. The measuring instrument is taken care of by a specially-assigned person, and irrelevant persons can not touch the measuring instrument. And (4) recording the reading of the measuring instrument and the measuring time by an inspector after the steam turbine test is started. The main measurement nodes are: preheating a steam turbine for 20 min; before the steam turbine is started; when the turbine reaches the highest rated rotating speed; before the turbine is stopped; stopping and turning the steam turbine for 15 min; and after the turbine is completely cooled and the turning is stopped. And other measuring nodes can be adjusted according to the test requirements of the steam turbines of different types.

Further, the specific way of arranging the measuring instruments according to the measuring point arrangement diagram in the step two is as follows: the magnetic force measuring device is characterized in that a support and a magnetic base are adopted, the support is fixed on a base of a steam turbine, the support is used for fixing the magnetic base, the support can be manufactured according to the actual arrangement condition on site, a measuring instrument is installed on the magnetic base, and a pointer of the measuring instrument points to the position of a measuring point.

The invention adopts the fixed connection of the bracket and the turbine foundation base, so that the magnetic base of the measuring instrument is fixed on the bracket, the measuring instrument is kept stable and is not influenced by the vibration of the main turbine test bed, and the pointer of the measuring instrument points to the position of a measuring point.

The method for solving the technical problem comprises the steps of 1, selecting a proper position of a steam turbine body as a measuring point, and drawing a measuring point layout drawing. The main measurement points are as follows: two measuring points are arranged at the intersection of the front bearing center line extension line and the middle section of the front bearing seat and the rear bearing center line extension line of the steam turbine front bearing seat, and two measuring points are arranged at the intersection of the front bearing center line extension line and the middle section of the steam turbine rear bearing seat, wherein the total number of the measuring points is 4. The method is used for measuring the elevation change of the front bearing seat and the rear bearing seat of the steam turbine. Two axial measuring points are symmetrically arranged on the left side and the right side of the end surface (vertical to the center line of the steam turbine) of the front bedplate of the steam turbine cylinder, and two radial measuring points are symmetrically arranged on the end surfaces (parallel to the center line of the steam turbine) of the two sides; the measuring points are also arranged on the end surface of the bedplate at the rear part of the steam turbine cylinder according to the mode, and the total number is 8. The displacement measuring device is used for measuring displacement changes of front and rear bedplate of the steam turbine. 2. And manufacturing a measuring instrument mounting bracket according to the positions of the measuring points. The instrument mounting bracket is mainly used for front and rear bearing seat elevation measuring instruments so as to ensure the stability and the accuracy of measurement of the instruments. When the measuring instrument is installed, the baffle can be properly welded for fixing the measuring instrument. Simple mounting tables can be arranged at displacement measuring points of the front platen and the rear platen of the steam turbine by using pressing plates and cushion blocks and are used for mounting and using measuring instruments. 3. And arranging a measuring instrument. And arranging a dial indicator for measurement near each measuring point, adsorbing a magnetic base of the dial indicator on a bracket or an installation platform, fixing by using a baffle, indicating a pointer of the dial indicator on a finish machining surface or the upper surface of a bolt at the measuring point according to measurement requirements, and polishing the blank at the measuring position to a smooth surface by a fitter if no proper finish machining surface exists. 4. Before measurement, the inspector zeroes all the dial indicator pointers and records the initial state. And (4) recording the reading of the measuring instrument and the measuring time by a tester after the steam turbine test starts.

The invention has the beneficial effects that: the method and the device have the advantages that the detection requirements of external thermal expansion displacement data of the steam turbine air load test are met, the detection cost is reduced, the test installation period is shortened, the universality is high, and the method and the device are suitable for various steam turbine air load verification tests.

Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that features described in different dependent claims and herein may be combined in ways different from those described in the original claims. It is also to be understood that features described in connection with individual embodiments may be used in other described embodiments.