CN102004000B - Surface temperature detection system for rotation part in high-temperature high-pressure container - Google Patents

Abstract

The invention discloses a surface temperature detection system for rotating parts in a high-temperature and high-pressure container, and relates to a temperature detection technology. The structure of the present invention is: the pressure vessel cylinder wall (80) is connected with an infrared window and sealing interface assembly (10), an infrared window and sealing interface assembly (10), an infrared high-temperature optical fiber (20), an infrared temperature measuring module (30 ), the signal cable (70) and the computer (40) are sequentially connected back and forth; the infrared window and the sealing interface assembly (10) are spatially opposite to the rotating body (50) through the infrared radiation optical path (60). The invention can more accurately measure the surface temperature of objects in a wide medium and high temperature range of 250°C to 750°C; it can measure the surface temperature of rotating objects in high-temperature and high-pressure containers; The effect of emissivity changes caused by trait changes on infrared thermometry.

Description

Surface temperature detection system for rotating parts in high temperature and high pressure vessels

technical field

The invention relates to a temperature detection technology, in particular to a surface temperature detection system for rotating parts in a high-temperature and high-pressure (such as supercritical water vapor medium) container. Specifically, it is an online detection system that can be applied to the surface temperature of the rotor in the cylinder of a supercritical steam turbine. The system can be reliable under the condition of water vapor with supercritical parameters within a wide range of pressure in the cylinder of 22.2-33MPa and temperature of 250-750°C. Working, online monitoring of the rotor temperature in the cylinder, it can also be used to detect the surface temperature of the rotating object in the container under other similar work requirements.

Background technique

The sustained, rapid and healthy development of the power industry is the basis and guarantee for my country's social and economic development; at the same time, domestic pressure on energy and the environment has put forward higher and higher requirements for thermal power technology to increase efficiency and reduce emissions. The adoption of supercritical power generation technology is one of the main directions for improving the power generation efficiency of coal power units and reducing pollutant emissions internationally and domestically. The commissioning of supercritical units has played a vital role in reducing the basic coal consumption level of thermal power generation in my country. However, due to the high operating parameters and strong dynamic characteristics of supercritical units, the safety requirements for units are much higher than those of conventional units.

For a long time, due to the extremely high working parameters of the steam turbine unit (pressure exceeding 10MPa, temperature exceeding 400°C), conventional technology cannot meet people's needs for monitoring the working conditions of the components in the cylinder of the steam turbine. The steam turbine rotor, the core component in the cylinder of the steam turbine unit, is in a supercritical water vapor environment and has a large temperature change with the change of working conditions, which has a great impact on the thermal stress and thermal fatigue of the component. Mastering the important parameters (such as temperature distribution) of the core components in the supercritical generator set is the premise and basis for its safety monitoring and evaluation.

For components (including steam turbine rotors) in the high-temperature and high-pressure steam environment in the cylinder, there are no literature reports and practical applications of online detection technology using the window method. Especially when it is necessary to use cooling technology and have high speed and vibration characteristics of rotor components, the importance of online monitoring of the temperature field is self-evident.

Foreign steam turbine equipment manufacturers often use temperature probes to measure the steam temperature near the components in the steam turbine unit, which is an approximate substitute for the surface temperature of the components. For example, the international patented technology of Westinghouse Electric Company of the United States in 1988 has not yet seen major improvements; Siemens of Germany applied for patents such as temperature prediction of steam turbine rotor blades in 1997 with the idea of neural network technology combined with steam temperature detection. The above patents are all The window structure is not used.

At present, aviation turbine engines have relatively mature long-term online measurement of wall temperature of high-temperature rotating parts of the engine based on the window structure and the principle of infrared radiation temperature measurement. However, the working pressure parameters of aeroengines are far lower than the working parameters of supercritical water vapor, and the higher temperature parameters are very conducive to temperature measurement with colorimetric infrared radiation; The temperature range from 250°C to 700°C is too low for the dual-band colorimetric temperature measurement method, and is greatly affected by the emissivity for the single-band infrared temperature measurement method. It is difficult to measure temperature accurately by infrared temperature measurement.

Contents of the invention

The purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art, and provide a surface temperature detection system for rotating parts in a high-temperature and high-pressure (such as supercritical parameter water vapor medium) container. The system can work reliably when the pressure inside the container is as high as 22.2-35MPa and the temperature range is 250-700°C. It monitors the temperature information on the surface of the rotating parts in the container online through infrared radiation. It can also be used for other detection instrument technology under similar work requirements. field.

The purpose of the present invention is achieved like this:

The invention includes the cylinder wall of the pressure vessel to be detected and the rotating body in it;

It is equipped with infrared window and sealing interface assembly, infrared high temperature optical fiber, infrared temperature measurement module, computer system and signal cable;

An infrared window and sealing interface assembly are connected to the cylinder wall of the pressure vessel, and the infrared window and sealing interface assembly, infrared high-temperature optical fiber, infrared temperature measurement module, signal cable and computer are connected in sequence;

The infrared window and the sealing interface assembly are spatially opposite to the rotating body through the infrared radiation optical path.

working principle:

The rotating body in the cylinder wall of the pressure vessel continuously releases infrared thermal radiation, and the thermal radiation energy released by objects within 60 degrees of the infrared radiation optical path will pass through the infrared window and sealing interface components, and then propagate in the infrared high-temperature optical fiber to reach the infrared temperature measurement module , The infrared temperature measurement module converts the infrared radiation energy signal into an electrical signal that can be recognized by the computer, and provides it to the computer through the signal cable through the RS232 interface, and then displays and sets it through the software in the computer.

The present invention has following advantage and positive effect:

①It can more accurately measure the surface temperature of objects in a wide medium and high temperature range of 250°C to 750°C;

②It can measure the surface temperature of rotating objects in high-temperature and high-pressure containers;

③ It can largely eliminate the influence of emissivity changes caused by changes in the surface properties of the measured object on infrared temperature measurement after long-term operation.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Fig. 2 is a structural schematic diagram of an infrared window and a sealing interface assembly;

Fig. 3 is a structural schematic diagram of an infrared high-temperature optical fiber and a window interface;

Fig. 4 is the structural representation of infrared temperature measuring sensor;

Fig. 5 is the working principle diagram of computer software;

Fig. 6 is a working flow diagram of the computer software.

in:

10-window and sealing interface assembly,

11-window glass, 12-protective sleeve, 13-expanded graphite sealing ring,

14-Bolts, 15-Metal sealing ring, 16-Window interface components,

17-light gland assembly, 18-soft gasket ring;

20-infrared high temperature optical fiber,

21-fiber optic lens, 22-fiber optic interface;

30-infrared temperature measurement module,

31-long-band monochromatic sensor, 32-short-band colorimetric sensor, 33-signal conditioning board;

40 - computer,

41-Tracking judgment program block;

50-body of rotation;

60-infrared radiation optical path;

70 - signal cable;

80 - Pressure vessel cylinder wall.

Detailed ways

Below in conjunction with accompanying drawing and embodiment describe in detail:

1. Overall

As shown in Fig. 1, the present invention includes a cylinder wall 80 of a pressure vessel to be tested and a rotating body 50 therein;

An infrared window and sealing interface assembly 10, an infrared high-temperature optical fiber 20, an infrared temperature measurement module 30, a computer 40 and a signal cable 70 are provided;

An infrared window and sealing interface assembly 10 is connected to the cylinder wall 80 of the pressure vessel, and the infrared window and sealing interface assembly 10, the infrared high-temperature optical fiber 20, the infrared temperature measuring module 30, the signal cable 70 and the computer 40 are sequentially connected;

The infrared window and sealing interface assembly 10 is spatially opposite to the rotating body 50 through the infrared radiation optical path 60 .

2. Function block

1. Infrared window and sealing interface assembly 10

As shown in Figure 2, the infrared window and sealing interface assembly 10 includes a window glass 11, a window glass protective sleeve 12, an expanded graphite sealing ring 13, a bolt 14, a metal sealing ring 15, a window interface assembly 16, an optical fiber interface and a seal gland assembly 17 and soft backing ring 18;

The upper end surface of the window interface assembly 16 is connected with the optical fiber interface and the seal gland assembly 17 through bolts 14; the lower end surface of the window interface assembly 16 is connected with the cylinder wall 80 of the pressure vessel through bolts 14 and metal sealing ring 15;

In the middle of the window interface assembly 16, an expanded graphite sealing ring 13, a soft backing ring 18, a window glass protective sleeve 12 and a window glass 11 are sequentially arranged inwardly.

Its working principle is:

The cylinder wall 80 of the pressure vessel is connected with the window interface assembly 16 through a metal sealing ring 15, which can ensure the strength and sealing performance requirements; the middle section of the window glass 11 is sealed by an expanded graphite sealing ring 13, and the upper section has an optical fiber interface and a seal gland assembly 17. Tight, the lower section is separated from the pressure vessel cylinder wall 80 by a soft backing ring 18; the upper section and the lower section of the window glass 11 are cylinders, and the middle section is a circular frustum; there is a stainless steel window glass protective sleeve 12 on the outside of the window glass 11 lower section Provide protection and increase the anti-vibration rigidity; the cavity formed by the window glass 11, the optical fiber interface and the seal gland assembly 17 is filled with an expanded graphite sealing ring 13, which moves upward under high pressure, and the conical body squeezes the expanded graphite filler to form a seal Effect; the function of the soft backing ring 18 is to prevent the window glass 11 from colliding with the container wall when it moves downwards to cause fragmentation; the optical fiber interface and the seal gland assembly 17 also have an interface connected to the high-temperature infrared optical fiber.

The structure and function of its components are:

(1) Window glass 11

Window glass 11 is a kind of quartz glass rod, and the upper section and the lower section are cylinders, and the middle section is a conical frustum.

Used to conduct thermal radiation energy.

The selected materials generally include infrared quartz glass or sapphire, etc., which are a kind of window material that can not only transmit light and infrared radiation, but also have a certain heat intensity.

(2) Window glass protection sleeve 12

The window glass protective sleeve 12 is a stainless steel sleeve adapted to the shape of the window glass 11 to protect the window glass 11 .

(3) Expanded graphite sealing ring 13

Expanded graphite sealing ring 13 is a kind of expanded graphite cylindrical shape adapted to the shape of the upper part of the window glass protective sleeve 12, and plays a sealing role.

(4) Bolt 14

Bolt 14 is a kind of common standard part, plays fixing role.

(5) metal sealing ring 15

Metal sealing ring 15 is a kind of commonly used standard part, plays a sealing role.

(6) Windows interface component 16

The window interface assembly 16 is a metal cylinder, and a circle of flange rings extends outwards from the peripheral edges of its upper and lower end surfaces.

Its function is the cavity and interface of the window part.

(7) Gland assembly 17

The gland assembly 17 is a part with a flange structure in the middle and a cylindrical structure with inconsistent inner and outer diameters on the upper and lower sides.

Its function is to play the role of optical fiber interface and sealing.

(8) soft backing ring 18

Soft backing ring 18 is a kind of common parts, plays shock-absorbing effect.

2. Infrared high temperature optical fiber 20

As shown in FIG. 3 , the input end of the infrared high-temperature optical fiber 20 is provided with an interface 22 , and a lens group 21 is provided in the interface 22 .

There is an inner cylindrical structure above the gland assembly 17, and its diameter matches the interface 22 at the lower end of the infrared high-temperature optical fiber 20; there is a lens group 21 in the interface 22, and the radiation energy transmitted by the window can be incident through the lens group 21 The shape and size of the optical path 60 in FIG. 1 are also determined by the fiber bundle entering the infrared high-temperature optical fiber 20 .

3. Infrared temperature sensor 30

As shown in FIG. 4 , the infrared temperature sensor 30 includes a long-wave monochromatic sensor 31 and a short-wave colorimetric sensor 32 connected in parallel.

1) The long-wave band monochromatic sensor 31 is a near-infrared (0.7-1.1 μm) infrared detector;

Indium gallium arsenic (InGaAs) infrared detectors or lead sulfide (PbS) detectors are selected.

2) The short-wave band colorimetric sensor 32 is a short-wave infrared (1-3 μm) infrared detector.

A silicon photodiode type (Si) infrared detector is used.

The working principle of the infrared temperature sensor 30 is:

The infrared radiant energy transmitted by the infrared high-temperature optical fiber 20 is divided into two in the infrared temperature sensor 30, and enters the long-wave monochrome sensor 31 and the short-wave colorimetric sensor 32 respectively; output temperature indication value, the short-wave band colorimetric sensor 32 finally outputs the temperature indication value according to the emissivity ratio parameter; the temperature value and parameters output by the two sensors can be connected with the computer 40 through the signal cable 70 and RS232, and through the computer 40 software for display and setting.

4. Computer 40

The computer 40 includes a hardware configuration and its software.

1) The hardware configuration of the computer 40 is commonly used 486-level or above CPU motherboard, graphics card, general RS232 interface, monitor, keyboard and mouse and other input devices.

2) The software of the computer 40 is a tracking judgment program block.

As shown in FIG. 5 , the tracking judgment program block 41 includes signal acquisition, logic judgment, setting, output and so on.

The tracking judgment program block 41 can collect monochromatic and colorimetric temperature signals through the RS232 interface. If the colorimetric temperature > 500°C, output this temperature as the final value, and judge the monochromatic temperature signal at the same time; Consistent, and update the emissivity parameter; if the monochromatic temperature is <500°C and the colorimetric temperature display is wrong, then output the monochromatic temperature as the final value; the emissivity ratio parameter is determined by the specific test results during system installation, and generally should not be changed.

As shown in Figure 6, the workflow of the tracking judgment program block 41 comprises the following steps:

start 0;

① Read monochromatic temperature measurement T1 and colorimetric temperature measurement T2, monochromatic emissivity ε1——1;

②Judge whether T1<500°C, T2<500°C—2, if yes, go to step ④, otherwise go to step ③;

③Judge whether the absolute value of the difference between T1 and T2 is less than 0.5, that is, whether abs(T1-T2)<0.5—3, if yes, go to step ① after ε1=ε1-0.01—5, otherwise, pass ε1= ε1+0.01——jump to step ① after 6;

④Output T1——4;

End 7.

5. Infrared radiation optical path 60

The infrared radiation optical path 60 is a virtual optical path.

7. Signal cable 70

The signal cable 70 is a common item that transmits signals.

Claims (2)

1. a surface temperature detection system that is used for the high temperature and high pressure containers inner rotatable part comprises detected object pressure vessel casing wall (80) and rotary body (50) within it;

Be provided with infrared form and sealed interface assembly (10), infrared high temperature optical fiber (20), infrared measurement of temperature module (30), computing machine (40) and signal cable (70);

On pressure vessel casing wall (80), be connected with infrared form and sealed interface assembly (10), be connected successively before and after infrared form and sealed interface assembly (10), infrared high temperature optical fiber (20), infrared measurement of temperature module (30), signal cable (70) and the computing machine (40);

Infrared form and sealed interface assembly (10) are spatially relative with rotary body (50) by infrared radiation light path (60);

Described infrared form and sealed interface assembly (10) comprise sight glass (11), sight glass protection sleeve (12), expanded graphite O-ring seal (13), bolt (14), metal o-ring (15), window interface assembly (16), optical fiber interface and seal gland assembly (17) and soft gasket ring (18);

The upper surface of window interface assembly (16) is connected with optical fiber interface and seal gland assembly (17) by bolt (14); The lower surface of window interface assembly (16) is connected with pressure vessel casing wall (80) with metal o-ring (15) by bolt (14);

Inwardly be disposed with expanded graphite O-ring seal (13), soft gasket ring (18), sight glass protection sleeve (12) and sight glass (11) in the centre of window interface assembly (16);

It is characterized in that:

Described infrared measurement of temperature module (30) comprises long-wave band monochromatic sensor (31) parallel with one another and short-wave band colorimetric sensor (32);

Long-wave band monochromatic sensor (31) is a kind of near infrared infrared eye;

Short-wave band colorimetric sensor (32) is a kind of infrared eye of short-wave infrared;

Described computing machine (40) comprises cpu motherboard, video card, general RS232 interface, display, keyboard and mouse more than 486 grades commonly used.

2. by the detection method of the described surface temperature detection system of claim 1, it is characterized in that:

Comprise the following steps:

Beginning (0);

1. read monochromatic thermometric T1 and color comparison temperature measurement T2, monochromatic emissivity ε 1(1);

2. judge whether T1＜500 ℃, T2＜500 ℃ (2) are then to enter step 4., otherwise enter step 3.;

Whether the absolute value of difference of 3. judging T1 and T2 less than 0.5, and (3) are then to pass through ε 1=ε 1-0.01(5) after jump to step 1., otherwise through ε 1=ε 1+0.01(6) after jump to step 1.;

4. export T1(4);

Finish (7).

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