JPH06294687A - Thermometer for high temperature gas - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a high temperature gas thermometer with high measurement accuracy and heat resistance. [Configuration] To be substantially parallel to the flow of high temperature gas G,
The heat shield tube H is fixed to the optical fiber holder 1, and the optical fiber sensor 3 is arranged at the axial center of the heat shield tube. The sensor 3 has a black body portion 6a formed at the tip end portion 3a of the optical rod 5. , Its base end portion 3b is detachably optically coupled to the optical connector 7. The holder 1 and the optical connector 7 are attached to a cooling housing 8, and the optical fiber cable 9 optically coupled to the optical connector 7 is bundled out of the cooling housing 8 and led out, and cooling water W is introduced into the cooling housing. The bundling portion 10 of the optical fiber cable 9 is housed in at least one of the inflow and outflow pipes 11 and 12 for inflowing and outflowing the.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot gas thermometer for measuring the temperature of hot gas at the outlet of, for example, a gas turbine combustor.

[0002]

2. Description of the Related Art In the development of a high temperature gas turbine, it is necessary to measure the temperature of the high temperature gas during an actual load test or a single element test to evaluate the performance. Conventionally, as this type of high temperature gas thermometer, for example, there are a thermocouple thermometer and an optical pyrometer.

The former joins both ends of a pair of dissimilar metal members, arranges one of the joining points at the temperature measuring point of the high temperature gas, and holds the other joining point at a known reference temperature.
Since the potential difference generated between both junction points is approximately proportional to the temperature difference between both junction points, it is possible to measure the temperature of the above-mentioned high temperature gas by connecting the reference junction point side with a potentiometer. You can The reference junction and the potentiometer are connected by a metal lead wire for signal transmission.

In the latter case, a noble metal film is applied to the tip of an optical rod made of sapphire (single crystal alumina) to form a black body portion, and the optical rod and the black body portion form a sensor portion. It When the black body portion is arranged at the temperature measuring point of the high temperature gas, the light energy emitted from the black body portion in the high temperature atmosphere is guided to the detector portion through the optical rod and the signal transmission optical fiber. After converting this into a voltage signal, predetermined signal processing is performed, and the temperature calculated by Planck's equation is displayed on the display.

[0005]

By the way, in recent years, the outlet temperature of a gas turbine combustor has become high, and its maximum temperature is about to reach the 1900 ° C. level. When a thermocouple thermometer or an optical pyrometer is adopted at such a temperature level, there are the following problems. First, this will be described for a thermocouple thermometer. As described above, the thermocouple thermometer is configured such that one joining point of the dissimilar metal members is disposed in the high temperature gas and the thermoelectric material is retained on the low temperature side. That is, in the thermocouple thermometer, one of the joining points of the dissimilar metal members is arranged in the high temperature gas, while the thermocouple is fixed on the low temperature side. The heat energy at the junction is thermally conducted toward the other junction on the low temperature side, and the heat loss due to this heat conduction reduces the measurement accuracy of the outlet temperature of the gas turbine combustor.

Further, at one of the joint points of the dissimilar metal members arranged in the high temperature gas, the high heat energy radiates heat toward the low temperature side close to this, and the heat loss due to this heat radiation causes the gas turbine to lose heat. The accuracy of measuring the exit temperature of the combustor is further reduced. Further, there is a problem that the metal member forming the thermocouple cannot withstand high temperature gas and melts.

Next, the optical pyrometer will be described. In this optical pyrometer, an optical fiber sensor is formed by an optical rod and a black body part, and since the optical rod is made of a nonmetal made of sapphire, heat loss due to heat conduction is small, and gas turbine combustion due to this point There is little decrease in the accuracy of the outlet temperature measurement in the vessel. However, the high thermal energy of the black body portion radiates heat toward the low temperature side close to the black body portion, and the heat loss due to this heat radiation lowers the measurement accuracy of the outlet temperature of the gas turbine combustor.

On the other hand, since the optical fiber sensor consisting of the optical rod and the black body is made of heat-resistant sapphire, there is no fear of melting without being able to withstand high temperature gas. However, since the sensor is made of sapphire, which is thin and fragile, it is formed in a short size to ensure strength and is coupled to the optical fiber cable for signal transmission through the optical connector. However, there is a problem in that the glass optical fiber cable and the optical connector are melted when exposed to high temperature gas.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a high temperature gas thermometer having high measurement accuracy and heat resistance.

[0010]

A hot gas thermometer according to the present invention comprises at least one heat shield tube fixed to an optical fiber holder so as to be substantially parallel to the flow of hot gas,
An optical fiber sensor in which a black body is formed at the tip of the optical rod and the tip is disposed at the axial center of the heat shield tube, and the base end of the optical fiber sensor is detachably optically coupled. A connector, a cooling housing in which the holder and the optical connector are mounted, an optical fiber cable that is optically coupled to the optical connector and is led out as a bundle outside the cooling housing, and a cooling medium flows in and out of the cooling housing. And an inflow / outflow pipe for allowing the bundle of the optical fiber cables to be housed in at least one of these inflow / outflow pipes.

[0011]

According to the above construction, since the optical fiber sensor is formed of the optical rod and the black body, and the optical rod is made of a nonmetal such as sapphire, heat loss due to heat conduction can be reduced. However, the accuracy of measurement of the temperature of the high-temperature gas flow due to this heat conduction does not deteriorate much. In particular, since the optical fiber sensor is arranged so as to be substantially parallel to the flow of the high temperature gas, it is possible to measure each high temperature gas flow of each layer along the low temperature wall. The optical fiber sensor in the heat shield tube for measurement does not generate heat loss due to heat conduction due to the high temperature gas flow at a temperature lower than this, and can prevent deterioration of measurement accuracy due to this heat conduction.

Further, since the black body portion formed at the tip of the optical rod is covered with the heat shield tube, the high heat energy of the black body portion is radiated toward the low temperature wall adjacent thereto. Therefore, it is possible to effectively prevent the measurement loss of the high temperature gas flow temperature from being lowered due to the heat loss due to the heat radiation.

Further, by forming the optical fiber sensor in a short size, it is easy to inspect and replace it. On the other hand, in the optical fiber sensor including the optical rod and the black body part, since the sapphire is a heat resistant material, there is no fear of melting because it cannot withstand high temperature gas.
Moreover, since the optical fiber sensor, heat shield tube, optical connector and optical fiber cable for signal transmission are directly or indirectly cooled by the cooling medium flowing in and out of the cooling housing, they are melted in the high temperature gas. It is possible to provide a high-temperature gas thermometer having a long life, which is extremely resistant to heat.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a partially cutaway schematic side view showing an example of a high temperature gas thermometer M according to the present invention, and FIG. 2 is a front view of the high temperature gas thermometer M. In the figure, reference numeral 1 denotes an optical fiber holder, and a plurality of heat shield tubes H (H1, H2 ... Hn) are arranged in the optical fiber holder 1 so as to be substantially parallel to the flow of the high temperature gas G (G1, ... Gn). The vent holes 2 for the high-temperature gas G, which is fixed and flows into each of the heat shield tubes H, are formed.

The tip portion 3a of the optical fiber sensor 3 is inserted through the axial center of each heat shield tube H. In this optical fiber sensor 3, for example, a noble metal film is attached to the tip of an optical rod 5 made of sapphire (single crystal alumina) to form a black body portion 6a (FIG. 5). The sensor portion 6 is formed by 6a. The base end portion 3b of each optical fiber sensor 3 is detachably optically coupled to the optical connector 7 and mounted, and the holder 1 and the optical connector 7 are fixed to the cooling housing 8.

An optical fiber cable 9 is fixed to each of the optical connectors 7 by optical coupling, and the cooling housing 8 is provided.
The bundling portion 10 is led out of the. The cooling housing 8 has an inflow pipe 11 and an outflow pipe 12 through which a cooling medium, for example, cooling water W flows in and out of the inside 8a.
The outflow pipe 12 is provided with the optical fiber 9
The bundling portion 10 of is stored. The bundled portion 10 of the optical fibers 9 may be housed in the inflow pipe 11 or may be housed in both pipes 11 and 12 in a dispersed manner.
Further, it goes without saying that the inflow / outflow direction of the cooling water W in both the pipes 11 and 12 may be the opposite direction to the arrow direction.

FIG. 3 is a sectional view of a main part showing an example of application of the high temperature gas thermometer M for an example of outlet temperature measurement of a gas turbine combustor. In the figure, 21 is a casing,
22 is a combustor, and 23 is fuel noise. The temperature of the high temperature gas G immediately after the exit of the combustor 22 is measured by the high temperature gas thermometer M. That is, the fuel F from the fuel noise 23 is mixed with the inlet air A and burned inside the combustor 22, and the high temperature gas G from the combustor 22 is burned.
Is a plurality of heat shield tubes H (H1, H2 ... H in FIG.
n), and is discharged from each corresponding gas vent hole 2.

Since the tip 3a of the optical fiber sensor 3 is inserted through the axial center of each heat shield tube H,
The sensor unit 6 is exposed to the high temperature gas G. As a result, the radiated light L (FIG. 5) from the black body portion 6a which has reached the gas temperature is repeatedly reflected on the inner peripheral surface of the optical rod 5 by the known means shown in FIG. It is guided through the optical fiber 9 for signal transmission to the detector unit 30 from the optical connector 29. In the detector section 30, the incident light is separated by the interference filter 31, and the photodiode 3
The signal is detected by 2, converted into a voltage signal, amplified by the amplifier 33, A / D converted by the signal processor 34, and then displayed by the display 36 or the like in the system control system 35.

As is apparent from the above, according to the above configuration, the optical fiber sensor 6 is formed of the optical rod 5 and the black body portion 6a, and the optical rod 5 is made of a nonmetal such as sapphire. The heat loss due to heat conduction can be reduced, and the decrease in measurement accuracy due to this heat conduction is small. In particular, since the optical fiber sensor 3 is arranged so as to be substantially parallel to the flow of the high temperature gas G (G1, ... Gn), the low temperature wall 1 at the outlet of the combustor 22.
It is possible to measure each hot gas flow G1, ... Gn of each layer along a. For example, the optical fiber sensor 3 in the heat shield tube H2 that measures the hot gas flow G1 is a hot gas on the lower temperature side than this. Due to the flow Gn, heat loss due to heat conduction does not occur, and it is possible to prevent a decrease in measurement accuracy due to this heat conduction.

Further, since the black body portion 6a formed at the tip portion of the optical rod 5 is covered with the heat shield tube H, the high heat energy of the black body portion 6a is directed to the low temperature wall 1a adjacent thereto. It is possible to suppress the heat radiation by
It is possible to effectively prevent the measurement accuracy from deteriorating due to the heat loss due to this heat radiation. Further, the optical fiber sensor 3
By forming a short size, it is easy to perform maintenance and inspection.

On the other hand, in the optical fiber sensor 3 including the optical rod 5 and the black body portion 6a, since the sapphire is made of a heat-resistant material, there is no fear that the sapphire cannot withstand high temperature gas and melt. Moreover, the optical fiber sensor 3, the heat shield tube H, the optical connector 7, and the signal transmitting optical fiber cable 9 are directly or indirectly cooled by the cooling water W flowing into and out of the cooling housing 8.
It is possible to provide a high-temperature gas thermometer M which has extremely high heat resistance and has a long life without the risk of these being melted by the high-temperature gas G.

[0022]

As described above in detail, the present invention can provide a high temperature gas thermometer having high measurement accuracy and heat resistance.

[Brief description of drawings]

FIG. 1 is a partially cutaway schematic side view showing an example of a high temperature gas thermometer according to the present invention.

FIG. 2 is a front view of the high temperature gas thermometer.

FIG. 3 is a cross-sectional view of essential parts showing an example of adaptation of the high temperature gas thermometer for a gas turbine combustor.

FIG. 4 is a schematic explanatory diagram of a measurement control system of the high temperature gas thermometer.

FIG. 5 is an enlarged view of a sensor section of the high temperature gas thermometer.

[Explanation of symbols]

 1 Optical Fiber Holder 3 Optical Fiber Sensor 3a Optical Fiber Sensor Tip 3b Optical Fiber Sensor Base End 5 Optical Rod 6a Black Body 7 Optical Connector 8 Cooling Housing 9 Optical Fiber Cable 10 Optical Fiber Cable Bundle 11 Inlet Pipe 12 Outflow pipe H Heat shield pipe G High temperature gas W Cooling medium

Claims (1)

[Claims] 1. A heat shield tube fixed to an optical fiber holder so as to be substantially parallel to the flow of high-temperature gas, and a black body portion formed at the tip of the optical rod, and the axis of the heat shield tube. An optical fiber sensor having a distal end portion disposed in the section,
An optical connector in which a base end portion of the optical fiber sensor is detachably optically coupled, a cooling housing in which the holder and the optical connector are mounted, an optical connector that is optically coupled to the optical connector and is bundled to the outside of the cooling housing and led out. High temperature, characterized in that it comprises an optical fiber cable and an inflow / outflow pipe for inflowing / outflowing a cooling medium into / from the cooling housing, and the bundling portion of the optical fiber cable is housed in at least one of the inflow / outflow pipe Gas thermometer.