阅读说明：本技术 一种测量汽轮机低压转子相对于缸体膨胀量的装置及方法 (Device and method for measuring expansion amount of low-pressure rotor of steam turbine relative to cylinder body ) 是由 张宇 于 2020-04-28 设计创作，主要内容包括：本发明公开了一种测量汽轮机低压转子相对于缸体膨胀量的装置及方法,所述装置包括沿汽轮机低压转子的膨胀方向上设置的第一电涡流探头和第二电涡流探头且所述第一电涡流探头和所述第二电涡流探头分别位于汽轮机低压转子两侧,所述汽轮机低压转子相对于缸体膨胀量大的一侧设置的电涡流探头为第一电涡流探头,所述汽轮机低压转子相对于缸体膨胀量小的一侧设置的电涡流探头为第二电涡流探头,所述第一电涡流探头与所述汽轮机低压转子探头之间的距离大于所述第二电涡流探头与所述汽轮机低压转子探头之间的距离。(The invention discloses a device and a method for measuring the expansion amount of a low-pressure rotor of a steam turbine relative to a cylinder body, wherein the device comprises a first eddy current probe and a second eddy current probe which are arranged along the expansion direction of the low-pressure rotor of the steam turbine, the first eddy current probe and the second eddy current probe are respectively positioned at two sides of the low-pressure rotor of the steam turbine, the eddy current probe arranged at one side of the low-pressure rotor of the steam turbine, which has a large expansion amount relative to the cylinder body, is a first eddy current probe, the eddy current probe arranged at one side of the low-pressure rotor of the steam turbine, which has a small expansion amount relative to the cylinder body, is a second eddy current probe, and the distance between the first eddy current probe and the low-pressure rotor probe of the steam turbine is larger than the distance between the second eddy current probe.)

1. The device for measuring the expansion amount of the low-pressure rotor of the steam turbine relative to the cylinder body is characterized in that a first eddy current probe and a second eddy current probe are arranged in the expansion direction of the low-pressure rotor of the steam turbine, a convex shoulder is arranged on the low-pressure rotor of the steam turbine, the first eddy current probe and the second eddy current probe are respectively positioned on two sides of the convex shoulder, the eddy current probe arranged on one side of the low-pressure rotor of the steam turbine relative to the small expansion amount of the cylinder body is the first eddy current probe, the eddy current probe arranged on one side of the low-pressure rotor of the steam turbine relative to the large expansion amount of the cylinder body is the second eddy current probe, and the distance between the first eddy current probe and the convex shoulder is smaller than the distance between the second eddy current probe and the convex shoulder.

2. The apparatus for measuring the amount of expansion of a low pressure rotor of a steam turbine relative to a cylinder block of claim 1, wherein the first eddy current probe and the second eddy current probe have the same span.

3. The apparatus for measuring the amount of expansion of a low pressure rotor of a steam turbine relative to a cylinder block of claim 1 wherein the distance between the first and second eddy current probes is twice the range of eddy current probes.

4. The apparatus for measuring the amount of expansion of a low pressure rotor of a steam turbine relative to a cylinder block of claim 1 wherein said shoulder is of a laminar construction.

5. A method for measuring the expansion amount of a low-pressure rotor of a steam turbine relative to a cylinder body is characterized by comprising the following steps:

s1: arranging a first eddy current probe and a second eddy current probe along the expansion direction of a low-pressure rotor of the steam turbine, wherein the first eddy current probe and the second eddy current probe are respectively positioned at two sides of a convex shoulder on the low-pressure rotor of the steam turbine, the eddy current probe arranged at one side of the low-pressure rotor of the steam turbine, which has small expansion amount relative to a cylinder body, is a first eddy current probe, the eddy current probe arranged at one side of the low-pressure rotor of the steam turbine, which has large expansion amount relative to the cylinder body, is a second eddy current probe, and the distance between the first eddy current probe and the convex shoulder is smaller than the distance between the second eddy current probe and the convex shoulder;

s2: before the low-pressure rotor of the steam turbine does not work, the distance between the vertical surface of the distance measuring surface of the first eddy current probe and the vertical surface of the convex shoulder surface close to one side of the first eddy current probe is defined as L_A1, defining the distance L between the vertical surface of the distance measuring surface of the second eddy current probe and the vertical surface of the convex shoulder surface close to one side of the second eddy current probe_B1, the ranges of the first eddy current probe and the second eddy current probe are Z and L_A1 is less than Z, i.e. L_AThe value of 1 is measured by a first eddy current probe;

s3: defining the relative expansion amount of the low-pressure rotor of the steam turbine as P, wherein the eddy current probe arranged on the side of the low-pressure rotor of the steam turbine, which has large expansion amount relative to the cylinder body, is the second eddy current probe, and after the low-pressure rotor of the steam turbine works, the shoulder gradually tends to the second eddy current probe, so L_A2 is greater than L_AL is stated if the first eddy current probe is still able to measure its distance from the surface of the shoulder_A2 is less than Z, P ═ L_A2-L_A1; l is said if the first eddy current probe fails to measure its distance from the shoulder surface_A2 is greater than Z, and the distance between the second eddy current probe and the surface of the convex shoulder is L measured by the second eddy current probe_B2，L_B2 is less than L_B1，P＝2Z-L_A1-L_B2。

6. The method of measuring the amount of expansion of a low pressure rotor of a steam turbine relative to a cylinder block of claim 5 wherein the first and second eddy current probes are selected to be used with the same range.

7. The method of measuring the amount of expansion of a low pressure rotor of a steam turbine relative to a cylinder block of claim 5 wherein the distance between the first and second eddy current probes is set to twice the span of the eddy current probes.

8. A method of measuring the amount of expansion of a low pressure rotor of a steam turbine relative to a cylinder block according to claim 5 wherein said shoulder is of a laminar construction.

9. The method of claim 5 wherein said first eddy current probe and said second eddy current probe are each 50mm eddy current probes.

10. The method of measuring the amount of expansion of a low pressure rotor of a steam turbine relative to a cylinder block of claim 9 wherein the first eddy current probe and the second eddy current probe are each 18mm in span.

Technical Field

The invention belongs to the technical field of semiconductor laser packaging, and particularly relates to a device and a method for measuring expansion of a low-pressure rotor of a steam turbine relative to a cylinder body.

Background

In the starting and stopping processes of the steam turbine, because the heat exchange conditions of the rotor and the cylinder are different, the rotor and the cylinder are different when expanding or contracting, and compared with the rotor and the cylinder, the rotor has small mass and large area participating in heat exchange, namely the mass-to-surface ratio is small; the mass of the cylinder is large, the area participating in heat exchange is small, and the mass-to-surface ratio is large. During heating and cooling, the temperature of the rotor rises or falls faster than the cylinder, i.e. the rotor expands more than the cylinder during heating and contracts more than the cylinder during cooling. Monitoring the differential expansion is an important task in the starting and stopping process of the unit. In order to avoid friction of the dynamic and static parts caused by the change of the axial clearance to a dangerous degree, the relative expansion value needs to be monitored, and the value is in a reasonable range by adjusting the operation mode of the steam turbine, so the accuracy of measuring the relative expansion value is particularly important. Particularly, the expansion of the low-pressure cylinder rotor relative to the cylinder body can reach about 20mm due to the relatively large value, and certain difficulty is brought to measurement.

The low-pressure rotor expansion measurement technology mainly adopted at present mainly has two modes:

1. the LVDT type is a measuring mode of a differential linear sensor, the measuring mode is contact type measuring, two wear-resisting heads are adopted at a measuring end to clamp a convex shoulder of a rotor, and the wear-resisting heads move along with the convex shoulder when the rotor expands, so that the measuring purpose is achieved. The biggest disadvantage of this measurement method is the wear of the wear head, because the wear head and the rotor are inevitably rubbed by the rotor rotating at high speed of about 3000 rpm, and the measurement effect is generated after the wear head is worn by long-time operation.

2. The eddy current type is to adopt an eddy current probe to measure, the monitoring distance of the eddy current probe in the mode must be in a linear interval, but the eddy current probe adopts a probe which is 50mm at the maximum at present, the linear interval can reach about 18mm at the maximum, the measurement requirement cannot be met, and the detection exceeding the measurement interval is inaccurate.

Disclosure of Invention

The invention aims to: the device and the method for measuring the expansion amount of the low-pressure rotor of the steam turbine relative to the cylinder body adopt a measuring method of mutual compensation of two eddy current sensors, and better solve the problems of abrasion and insufficient measuring linear interval.

The technical scheme of the invention is as follows: the device for measuring the expansion amount of the low-pressure rotor of the steam turbine relative to the cylinder body is characterized in that a first eddy current probe and a second eddy current probe are arranged in the expansion direction of the low-pressure rotor of the steam turbine, a convex shoulder is arranged on the low-pressure rotor of the steam turbine, the first eddy current probe and the second eddy current probe are respectively positioned on two sides of the convex shoulder, the eddy current probe arranged on one side of the low-pressure rotor of the steam turbine relative to the small expansion amount of the cylinder body is the first eddy current probe, the eddy current probe arranged on one side of the low-pressure rotor of the steam turbine relative to the large expansion amount of the cylinder body is the second eddy current probe, and the distance between the first eddy current probe and the convex shoulder is smaller than the distance between the second eddy current probe and the.

Preferably, the first and second eddy current probes have the same range.

Preferably, the distance between the first and second eddy current probes is twice the eddy current probe range.

Preferably, the shoulder is of a laminar construction.

The invention also provides another technical scheme: the method for measuring the expansion amount of the low-pressure rotor of the steam turbine relative to the cylinder body comprises the following steps:

s1: arranging a first eddy current probe and a second eddy current probe along the expansion direction of a low-pressure rotor of the steam turbine, wherein the first eddy current probe and the second eddy current probe are respectively positioned at two sides of a convex shoulder on the low-pressure rotor of the steam turbine, the eddy current probe arranged at one side of the low-pressure rotor of the steam turbine, which has small expansion amount relative to a cylinder body, is a first eddy current probe, the eddy current probe arranged at one side of the low-pressure rotor of the steam turbine, which has large expansion amount relative to the cylinder body, is a second eddy current probe, and the distance between the first eddy current probe and the convex shoulder is smaller than the distance between the second eddy current probe and the convex shoulder;

s2: before the low-pressure rotor of the steam turbine does not work, the distance between the vertical surface of the distance measuring surface of the first eddy current probe and the vertical surface of the convex shoulder surface close to one side of the first eddy current probe is defined as L_A1, defining the distance L between the vertical surface of the distance measuring surface of the second eddy current probe and the vertical surface of the convex shoulder surface close to one side of the second eddy current probe_B1, the ranges of the first eddy current probe and the second eddy current probe are Z and L_A1 is less thanZ, i.e. L_AThe value of 1 is measured by a first eddy current probe;

s3: defining the relative expansion amount of the low-pressure rotor of the steam turbine as P, wherein the eddy current probe arranged on the side of the low-pressure rotor of the steam turbine, which has large expansion amount relative to the cylinder body, is the second eddy current probe, and after the low-pressure rotor of the steam turbine works, the shoulder gradually tends to the second eddy current probe, so L_A2 is greater than L_AL is stated if the first eddy current probe is still able to measure its distance from the surface of the shoulder_A2 is less than Z, P ═ L_A2-L_A1; l is said if the first eddy current probe fails to measure its distance from the shoulder surface_A2 is greater than Z, and the distance between the second eddy current probe and the surface of the convex shoulder is L measured by the second eddy current probe_B2，L_B2 is less than L_B1，P＝2Z-L_A1-L_B2。

Preferably, the first and second eddy current probes are selected to be used with the same range.

Preferably, the distance between the first and second eddy current probes is set to twice the eddy current probe span distance.

Preferably, the shoulder is of a laminar construction.

Preferably, the first eddy current probe and the second eddy current probe are both 50mm eddy current probes.

Preferably, the first eddy current probe and the second eddy current probe are both 18mm in range.

The invention has the beneficial effects that:

1. the non-contact measurement can be realized, the eddy current probe that the one side that the steam turbine low pressure rotor expansion volume is great relatively set up is first eddy current probe, the eddy current probe that the one side that the steam turbine low pressure rotor expansion volume is little relatively set up is the second eddy current probe, first eddy current probe with the distance between the steam turbine low pressure rotor probe is greater than the second eddy current probe with the distance between the steam turbine low pressure rotor probe, the eddy current probe that the one side that the expansion volume is great relatively set up is far away relatively apart from the steam turbine low pressure rotor, and the probe that does not wear when guaranteeing normal operating or reaching trip value.

2. When the relative expansion amount of the low-pressure rotor of the steam turbine is large, even if the relative expansion amount exceeds the linear measuring region of one eddy current probe, the other eddy current probe can measure.

3. The measured value of the relative expansion amount of the low-pressure rotor of the steam turbine is calculated through an accurate formula, and the measurement accuracy is greatly improved.

Drawings

FIG. 1 is a view showing the device for measuring the expansion of the low-pressure rotor of the steam turbine relative to the cylinder body according to the present invention.

FIG. 2 is a simplified calculation of step 2 of the present invention.

FIG. 3 is a simplified calculation of step 3 of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

Referring to fig. 1, the present invention provides a device for measuring the expansion amount of a low-pressure rotor 3 of a steam turbine relative to a cylinder, wherein a first eddy current probe 1 and a second eddy current probe 2 are arranged along the expansion direction of the low-pressure rotor 3 of the steam turbine, a shoulder 4 is arranged on the low-pressure rotor 3 of the steam turbine, the first eddy current probe 1 and the second eddy current probe 2 are respectively arranged on two sides of the shoulder 4, the eddy current probe arranged on the side of the low-pressure rotor 3 of the steam turbine relative to the cylinder with the small expansion amount is the first eddy current probe 1, the eddy current probe arranged on the side of the low-pressure rotor 3 of the steam turbine relative to the cylinder with the large expansion amount is the second eddy current probe 2, the distance between the first eddy current probe 1 and the probe of the low-pressure rotor 3 of the steam turbine is smaller than the distance between the second eddy current probe 2 and the probe of, the measuring ranges of the first eddy current probe 1 and the second eddy current probe 2 are the same, and the distance between the first eddy current probe 1 and the second eddy current probe 2 is twice of the measuring range of the eddy current probes.

The invention also provides a method for measuring the expansion amount of the low-pressure rotor 3 of the steam turbine relative to the cylinder body, which comprises the following steps:

s1: a first eddy current probe 1 and a second eddy current probe 2 are arranged along the expansion direction of a low-pressure rotor 3 of the steam turbine, the first eddy current probe 1 and the second eddy current probe 2 are respectively positioned at two sides of a convex shoulder 4 on the low-pressure rotor 3 of the steam turbine, the eddy current probe arranged on the side of the low-pressure rotor 3 of the steam turbine with small expansion amount relative to the cylinder body is a first eddy current probe 1, the eddy current probe arranged on the side of the low-pressure rotor 3 of the steam turbine with large expansion amount relative to the cylinder body is a second eddy current probe 2, the distance between the first eddy current probe 1 and the probe of the turbine low-pressure rotor 3 is smaller than the distance between the second eddy current probe 2 and the probe of the turbine low-pressure rotor 3, the first eddy current probe 1 and the second eddy current probe 2 have the same range, and the distance between the first eddy current probe 1 and the second eddy current probe 2 is twice of the range of the eddy current probes;

s2: referring to fig. 2, before the low-pressure rotor 3 of the steam turbine does not work, a distance L between a vertical plane where a distance measuring surface of the first eddy current probe 1 is located and a vertical plane where a surface of the shoulder 4 close to one side of the first eddy current probe 1 is located is defined_A1, defining the distance L between the vertical surface of the distance measuring surface of the second eddy current probe 2 and the vertical surface of the convex shoulder 4 close to one side of the second eddy current probe 2_B1, the ranges of the first eddy current probe 1 and the second eddy current probe 2 are Z and L_A1 is less than Z, i.e. L_AThe value of 1 is measured by the first eddy current probe 1;

s3: referring to fig. 3, the relative expansion of the low pressure rotor 3 of the steam turbine is defined as P, since the eddy current probe arranged on the side of the low pressure rotor 3 of the steam turbine where the expansion of the cylinder is large is the second eddy current probe 2, and the shoulder 4 gradually tends to the second eddy current probe 2 after the low pressure rotor 3 of the steam turbine operates, L_A2 is greater than L_A1, if the first eddy current probe 1 is still able to measure its distance from the surface of the shoulder 4If it is separated, then L is indicated_A2 is less than Z, P ═ L_A2-L_A1; if the first eddy current probe 1 fails to measure its distance from the surface of the shoulder 4, L is stated_A2 is larger than Z, and the distance between the second eddy current probe 2 and the surface of the convex shoulder is L measured by the second eddy current probe 2_B2，L_B2 is less than L_B1，P＝2Z-L_A1-L_B2。

The device realizes contact-free measurement, the eddy current probe arranged on one side with relatively large expansion amount of the low-pressure rotor 3 of the steam turbine is the first eddy current probe 1, the eddy current probe arranged on one side with relatively small expansion amount of the low-pressure rotor 3 of the steam turbine is the second eddy current probe 2, the distance between the first eddy current probe 1 and the probe of the low-pressure rotor 3 of the steam turbine is larger than the distance between the second eddy current probe 2 and the probe of the low-pressure rotor 3 of the steam turbine, and the eddy current probe arranged on one side with relatively large expansion amount is relatively far away from the low-pressure rotor 3 of the steam turbine, so that the probe is not worn during normal operation or when a trip value is reached.

When the relative expansion amount of the low-pressure rotor 3 of the steam turbine is large, even if the relative expansion amount exceeds the linear measuring region of one eddy current probe, the other eddy current probe can measure.

The measured value of the relative expansion amount of the low-pressure rotor 3 of the steam turbine is calculated by an accurate formula, and the measurement accuracy is greatly improved.

The shoulder 4 is a raised tab of negligible thickness on the low-pressure rotor of the steam turbine.

The first eddy current probe and the second eddy current probe adopt 50 mm-sized eddy current probes, and the measuring range of the probes is 18 mm.

It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.