JP2012073196A - Distributed optical fiber temperature sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a distributed optical fiber temperature sensor that radiates heat of a heat sink of a light amplification module without attaching a heat-radiation heat sink to the light amplification module and a Peltier module of a reference temperature section, and in which a housing is made compact and the power consumption is lowered.SOLUTION: The distributed optical fiber temperature sensor includes a light source 1, the light amplification module 2 for amplifying emission light from the light source 1, a temperature measurement optical fiber 6 that propagates the emission light amplified and emitted by the light amplification module 2 and measures a temperature distribution; and the Peltier module 11 for warming the reference temperature section 4 arranged at a part of the temperature measurement optical fiber 6 to control the temperature of reference temperature section 4. The Peltier module 11 is configured to absorb heat from the light amplification module 2, warms the reference temperature section 4 with the absorbed heat, and controls the its temperature.

Description

  The present invention relates to a distributed optical fiber temperature sensor that detects Raman scattered light and measures temperature.

  The distributed optical fiber temperature sensor is a temperature sensor that detects Raman scattered light and measures temperature. The configuration of the distributed optical fiber temperature sensor and the principle of temperature measurement are described in Patent Document 1, for example.

  FIG. 1 is a block diagram showing a general configuration of a distributed optical fiber temperature sensor. Pulse light (emitted light) emitted from the light source 1 is amplified by the optical amplifier module 2 and input to the optical filter 3. This pulsed light is output from the optical filter 3 with almost no loss, and is input to the external temperature measurement optical fiber 6 through the reference temperature unit 4. While the pulsed light propagates through the temperature measuring optical fiber 6, Stokes (ST light) and anti-Stokes (AS light) which are Raman scattered light are generated by the pulsed light. These Raman scattered lights generated in the rear return to the optical filter 3 and are demultiplexed into the respective paths. The demultiplexed light is converted into an electrical signal by the light receiver 7, amplified by the amplifier 8, averaged by the signal processing circuit 9, and converted to temperature by the temperature calculation circuit 10. In this way, the distributed optical fiber temperature sensor measures the temperature distribution of the optical fiber.

  The reference temperature unit 4 is obtained by winding a part of an optical fiber 6 for temperature measurement (an optical fiber of about several tens of meters to several hundreds of meters) into a case by winding it in a coil shape. Inside, a temperature sensor such as a thermistor is arranged as a reference temperature portion thermometer 5. The reference temperature section thermometer 5 is used to take a temperature reference of the distributed optical fiber temperature sensor. The reference temperature unit 4 is attached with a Peltier module or a heater, and is controlled so as to have a constant temperature even if the surrounding temperature environment (the internal temperature of the distributed optical fiber temperature sensor main body) changes.

  As another example of the method for preventing the temperature change of the reference temperature unit 4, as described in Patent Document 2, an electric circuit (light source 1, signal processing circuit 9, temperature calculation circuit) serving as a reference temperature unit 4 and a heat source is disclosed. 10) and the like, there is a method of providing a partition wall made of a metal plate having high heat conductivity.

  The optical amplifier module 2 generates heat by an internal pumping LD (semiconductor laser). For this reason, the optical amplifier module 2 and the reference temperature unit 4 are usually arranged separately from each other in the casing, and each has its own heat dissipation mechanism. The reason is that the heat of the optical amplifier module 2 may circulate to the reference temperature unit 4 and affect the temperature control of the reference temperature unit 4. For example, when the temperature of the optical amplifier module 2 is 40 ° C. and the reference temperature unit 4 disposed near the optical amplifier module 2 is set to 30 ° C., the heat from the optical amplifier module 2 enters the reference temperature unit 4. It is possible that the cooling capacity of the Peltier module will be exceeded and 40 ° C will be reached even though it is desired to set it to 30 ° C. For this reason, the optical amplifier module 2 and the reference temperature unit 4 are arranged so as not to interfere as much as possible so that heat can be dissipated independently.

  As a heat dissipation method, the optical amplifier module 2 is disposed apart from the reference temperature unit 4 and a heat sink for heat dissipation is attached. If necessary, a cooling fan is attached to the housing of the distributed optical fiber temperature sensor, the air inside the housing is discharged to the outside, and the heat of the optical amplifier module 2 is taken away through the heat sink. About the reference temperature part 4, a heat sink is attached to the surface on the opposite side to the contact surface with the reference temperature part 4 of a Peltier module, and heat dissipation and heat absorption are carried out.

JP 2009-174987 A JP 2008-107196 A

  As described above, when a heat sink for heat dissipation is attached to the optical amplifier module or the reference temperature unit Peltier module, the number of parts to be housed in the distributed optical fiber temperature sensor increases, and the optical amplifier module and the reference temperature unit are connected. Problems such as an increase in the size of the housing to be stored and an increase in weight occur. In addition, when a cooling fan is attached to the housing, the housing is not compact, and power consumption for driving the fan increases, and the number of repairs due to fan failure increases. . Therefore, there is a demand for a distributed optical fiber temperature sensor capable of radiating the optical amplifier module and controlling the temperature of the reference temperature portion without using a heat sink or a cooling fan.

  The object of the present invention is that the heat radiation of the optical amplifier module and the temperature control of the reference temperature part can be performed without attaching a heat sink for heat radiation to the optical amplifier module or the Peltier module of the reference temperature part, and without using a cooling fan. In addition, a distributed optical fiber temperature sensor that can achieve a compact casing and low power consumption is provided.

  The distributed optical fiber temperature sensor according to the present invention has the following features.

  A light source, an optical amplifier module for amplifying the light emitted from the light source, a temperature measuring optical fiber for measuring the temperature distribution by propagating the light emitted after being amplified by the optical amplifier module, and the temperature A distributed optical fiber temperature sensor having a Peltier module for heating a reference temperature section provided in a part of the measurement optical fiber and controlling the temperature, wherein the Peltier module is connected to the optical amplifier module. The reference temperature section is heated by the absorbed heat and the temperature is controlled.

  According to the present invention, in the distributed optical fiber temperature sensor, the optical amplifier module can dissipate heat without a heat sink or a cooling fan. For this reason, the housing for housing the optical amplifier module and the reference temperature portion can be made compact. Furthermore, since the efficiency of the Peltier module is improved, low power consumption can be achieved.

It is a block diagram which shows the general structure of a distributed optical fiber temperature sensor. It is a figure which shows arrangement | positioning of an optical amplifier module and a reference | standard temperature part, and the flow of heat of the distributed optical fiber temperature sensor by this invention. It is a figure which shows the structure of the 1st Example of the distributed optical fiber temperature sensor by this invention. It is a figure which shows the structure of the 2nd Example of the distributed optical fiber temperature sensor by this invention. It is a figure which shows the structure of the 3rd Example of the distributed optical fiber temperature sensor by this invention. It is a figure which shows the structure of the 4th Example of the distributed optical fiber temperature sensor by this invention.

  The distributed optical fiber temperature sensor according to the present invention has a configuration as shown in FIG. 1 and has the following characteristics.

  FIG. 2 is a diagram showing the arrangement of the optical amplifier module 2 and the reference temperature unit 4 and the heat flow 16 of the distributed optical fiber temperature sensor according to the present invention. A Peltier module (Peltier element) 11 is used as a temperature control element of the reference temperature unit 4.

  Here, the Peltier module is an element that utilizes the Peltier effect that heat is transferred from one metal to the other when an electric current is passed through a joint between two kinds of metals. When a direct current is passed, one surface absorbs heat and the other surface generates heat. This relationship is reversed when the polarity of the current is reversed. The ability of the Peltier module is determined by the temperature difference between the two sides. For example, in order to set the heat absorption side to a lower temperature, it is necessary to dissipate heat on the heat generation side so that the temperature does not rise. On the other hand, in order to set the heat generation side to a higher temperature, it is necessary not to lower the temperature of the heat absorption side too much.

  The Peltier module 11 is attached so that the heat absorption surface 15 is in contact with the metal plate 12, and the surface opposite to the heat absorption surface 15 (heat radiation surface) is attached to the reference temperature unit 4. Further, the heat generating surface 14 of the optical amplifier module 2 is disposed so as to be in contact with the metal plate 12.

  The set temperature of the reference temperature unit 4 is set under the condition that the internal temperature of the distributed optical fiber temperature sensor body (housing) is the highest, that is, the maximum value of the operating temperature specification of the sensor (distributed optical fiber temperature sensor body). Set the temperature higher than the internal temperature of the sensor body when operating at the maximum temperature. At that time, it is preferable from the viewpoint that the temperature of the reference temperature unit 4 is easily controlled to be constant so as not to be affected (does not affect) the ambient temperature of the reference temperature unit 4. .

  As a result, the heat generated in the optical amplifier module 2 moves as indicated by the heat flow 16 and is absorbed by the Peltier module 11, so that heat radiation countermeasure parts such as a heat sink and a fan for the optical amplifier module 2 are used. Is not required, and the housing (sensor body) for housing the optical amplifier module 2 and the reference temperature unit 4 can be made compact and lightweight.

  In addition, by setting the temperature of the reference temperature unit 4 as described above, the Peltier module 11 is always opposite to the contact surface with the reference temperature unit 4 within the operating temperature range of the distributed optical fiber temperature sensor body. It absorbs heat from the surface (the endothermic surface 15), generates heat at the contact surface with the reference temperature unit 4, and warms the reference temperature unit 4 to control the temperature constant.

  Therefore, as shown in FIG. 2, the heat absorption surface 15 of the Peltier module 11 is disposed so as to be in contact with the metal plate 12 having good thermal conductivity such as aluminum or copper, and the heat generation surface of the optical amplifier module 2 is disposed on the same metal plate 12 Install so that 14 contacts. The heat of the optical amplifier module 2 diffuses through the metal plate 12, but is absorbed by the Peltier module 11 and becomes a heat source for heating the reference temperature unit 4. Since the metal plate 12 is cooled by the heat flow 16, the optical amplifier module 2 is also cooled.

  The heat absorbing surface 15 of the Peltier module 11 and the heat generating surface 14 of the optical amplifier module 2 may be brought into direct contact without using the metal plate 12. In this case, the heat of the optical amplifier module 2 is directly absorbed by the Peltier module 11 and becomes a heat source for heating the reference temperature unit 4.

  Since the distributed optical fiber temperature sensor according to the present invention has the above-described configuration, the Peltier module 11 absorbs the heat generated from the optical amplifier module 2 that normally merely radiates heat, and the heat is absorbed. The heat is used as a heat source for heating the reference temperature unit 4. Therefore, the optical amplifier module 2 can dissipate heat without a heat sink or a cooling fan, and the temperature of the reference temperature unit 4 can be kept constant without providing a heater or the like for heating the reference temperature unit 4 separately. Can be controlled. Accordingly, it is possible to reduce the size and weight of the housing that houses the optical amplifier module 2 and the reference temperature unit 4. Furthermore, since the heat absorbed by the Peltier module 11 is used to warm the reference temperature unit 4, the efficiency of the Peltier module 11 is improved, and as a result, low power consumption can be achieved.

  A first embodiment of a distributed optical fiber temperature sensor according to the present invention is shown in FIG. FIG. 3 shows only the optical amplifier module 2, the reference temperature unit 4, and the Peltier module 11 among the distributed optical fiber temperature sensors. The distributed optical fiber temperature sensor of the present embodiment has a configuration in which the heat absorption surface of the Peltier module 11 and the heat generation surface of the optical amplifier module 2 are in direct contact without using the metal plate 12 shown in FIG. . Therefore, the heat of the optical amplifier module 2 is directly absorbed by the Peltier module 11, and this absorbed heat becomes a heat source for warming the reference temperature unit 4 and controlling the temperature to be constant.

  With such a configuration, the optical amplifier module 2 can be cooled by the Peltier module 11, and a heat sink, a cooling fan, and a heater for heating the reference temperature unit 4 and controlling the temperature to be constant are unnecessary. Further, since the metal plate 12 is not required, the number of parts can be reduced, so that the housing for housing the optical amplifier module 2 and the reference temperature unit 4 can be made compact, lightweight, and low in power consumption.

  FIG. 4 shows a second embodiment of the distributed optical fiber temperature sensor according to the present invention. FIG. 4 shows only the optical amplifier module 2, the reference temperature unit 4, the Peltier module 11, and the metal plate 12 among the distributed optical fiber temperature sensors.

  In the distributed optical fiber temperature sensor of this embodiment, the Peltier module 11 is disposed on the metal plate 12, and the reference temperature unit 4 is disposed thereon. As described so far, the Peltier module 11 has the heat absorption surface in contact with the metal plate 12. Further, the optical amplifier module 2 is disposed on the metal plate 12. The optical amplifier module 2 is configured such that the heat generating surface is in contact with the metal plate 12.

  The set shown in FIG. 4 is housed inside the housing as it is. A heat insulating material may be appropriately disposed around these. As described above, with this configuration, the heat of the optical amplifier module 2 is absorbed by the Peltier module 11, and this absorbed heat becomes a heat source for warming the reference temperature unit 4 and controlling the temperature to be constant. Thus, the optical amplifier module 2 can be cooled, and a heat sink, a cooling fan, and a heater for controlling the temperature to be constant by heating the reference temperature unit 4 are not required.

  Furthermore, in the present Example 2, since it is a structure provided with the metal plate 12, the metal plate 12 plays the role of a heat sink, and the effect that more precise temperature control of the reference temperature part 4 can be acquired is acquired.

  FIG. 5 shows a third embodiment of the distributed optical fiber temperature sensor according to the present invention. FIG. 5 shows only the optical amplifier module 2, the reference temperature unit 4, the Peltier module 11, the metal plate 12, and the light source 1 among the distributed optical fiber temperature sensors.

  In the third embodiment, as in the second embodiment, the Peltier module 11 is disposed on the metal plate 12, and the reference temperature unit 4 is disposed thereon. The optical amplifier module 2 is also disposed on the metal plate 12. However, in FIG. 5, the Peltier module 11 is disposed on one surface of the metal plate 12, and the optical amplifier module 2 is disposed on the other surface. The heat absorption surface of the Peltier module 11 and the heat generation surface of the optical amplifier module 2 are in contact with the metal plate 12.

  The light source 1 requires a mechanism for radiating heat so that the light emitting element inside the light source 1 does not reach a high temperature.

  Therefore, as shown in FIG. 5, the light source 1 is arranged on the metal plate 12 on which the reference temperature unit 4 and the optical amplifier module 2 are arranged. At this time, the heat generating surface of the light source 1 is in contact with the metal plate 12. In FIG. 5, the light source 1 is disposed on the surface of the metal plate 12 on which the Peltier module 11 is disposed. The metal plate 12 also serves as a heat dissipation mechanism for the light source 1.

  With such a configuration, the heat of the light source 1 can also be used to warm the reference temperature unit 4, and the light source 1 can be cooled.

  For the light source 1 that generates heat, a dedicated metal heat sink is usually required. However, according to the third embodiment, since the metal plate 12 serves as the heat radiating plate, a dedicated heat radiating plate for the light source 1 is not necessary. As a result, the heat of the light source 1 can also be used for the reference temperature unit 4, and further power consumption can be reduced.

  In FIG. 5, the Peltier module 11 and the light source 1 are arranged on one surface of the metal plate 12, and the optical amplifier module 2 is arranged on the other surface of the metal plate 12, but the Peltier module 11 and the optical amplifier module are arranged. 2 and the light source 1 may be arranged on any surface of the metal plate 12. In any arrangement, the reference temperature unit 4 is naturally in contact with the heat generating surface of the Peltier module 11, and the heat generating surfaces of the amplifier module 2 and the light source 1 are in contact with the metal plate 12.

  FIG. 6 shows a fourth embodiment of the distributed optical fiber temperature sensor according to the present invention. The distributed optical fiber temperature sensor according to the fourth embodiment has a structure in which a heat sink 13 is added to the configuration of the distributed optical fiber temperature sensor according to the third embodiment. FIG. 6 shows the optical amplifier module 2, the reference temperature unit 4, the Peltier module 11, the metal plate 12, the light source 1, and the heat sink 13 among the distributed optical fiber temperature sensors.

  In the fourth embodiment, the Peltier module 11 and the heat sink 13 are disposed on one surface of the metal plate 12, and the optical amplifier module 2 and the light source 1 are disposed on the other surface of the metal plate 12. The heat absorption surface of the Peltier module 11 and the heat generation surface of the optical amplifier module 2 are in contact with the metal plate 12. The reference temperature unit 4 is disposed in contact with the heat generating surface of the Peltier module 11. The heat generating surface of the light source 1 may or may not be in contact with the metal plate 12.

  The heat sink 13 is attached on the metal plate 12 when more heat is generated from the optical amplifier module 2 or the light source 1 than necessary to warm the reference temperature unit 4 due to the influence of the ambient temperature, etc. It is for releasing a lot of heat. The heat sink 13 may be smaller than that normally attached to the optical amplifier module 2. The reason is that the Peltier module 11 of the reference temperature unit 4 absorbs the heat of the optical amplifier module 2. Therefore, by providing the heat sink 13, the size of the housing that houses the optical amplifier module 2 and the reference temperature unit 4 is slightly larger than those of the first to third embodiments, but is larger than the size of the conventional housing. Can be small.

  When the reference temperature unit 4 reaches the set temperature and the heat generation of the optical amplifier module 2 is larger than the heat absorption of the Peltier module 11, the metal plate 12 becomes unnecessarily hot and the reference temperature unit 4 cannot be controlled. There is a possibility. In the distributed optical fiber temperature sensor of the fourth embodiment, this problem is prevented by releasing heat from the heat sink 13, and more precise temperature control is possible.

  In FIG. 6, the Peltier module 11 and the heat sink 13 are arranged on one surface of the metal plate 12, and the optical amplifier module 2 and the light source 1 are arranged on the other surface of the metal plate 12. The heat sink 13, the optical amplifier module 2, and the light source 1 may be disposed on any surface of the metal plate 12. In any arrangement, the reference temperature unit 4 is naturally arranged so as to be in contact with the heat generating surface of the Peltier module 11.

  DESCRIPTION OF SYMBOLS 1 ... Light source, 2 ... Optical amplifier module, 3 ... Optical filter, 4 ... Reference temperature part, 5 ... Thermometer for reference temperature part, 6 ... Optical fiber for temperature measurement, 7 ... Light receiver, 8 ... Amplifier, 9 ... Signal Processing circuit, 10 ... temperature calculation circuit, 11 ... Peltier module, 12 ... metal plate, 13 ... heat sink, 14 ... heat generating surface of optical amplifier module, 15 ... heat absorbing surface of Peltier module, 16 ... heat flow.

Claims (5)

A light source, an optical amplifier module for amplifying the light emitted from the light source, a temperature measuring optical fiber for measuring the temperature distribution by propagating the light emitted after being amplified by the optical amplifier module, and the temperature A distributed optical fiber temperature sensor having a Peltier module for heating a reference temperature section provided in a part of a measurement optical fiber and controlling the temperature,
The distributed optical fiber characterized in that the Peltier module is provided so as to absorb heat from the optical amplifier module and to control the temperature by heating the reference temperature portion with the absorbed heat. Temperature sensor. A light source, an optical amplifier module for amplifying the light emitted from the light source, a temperature measuring optical fiber for measuring the temperature distribution by propagating the light emitted after being amplified by the optical amplifier module, and the temperature A distributed optical fiber temperature sensor having a Peltier module for heating a reference temperature section provided in a part of a measurement optical fiber and controlling the temperature,
A metal plate for disposing the optical amplifier module and the Peltier module;
The optical amplifier module has its heating surface in contact with the metal plate,
The Peltier module has an endothermic surface in contact with the metal plate and an exothermic surface located on the opposite side of the endothermic surface in contact with the reference temperature portion.
A distributed optical fiber temperature sensor. The distributed optical fiber temperature sensor according to claim 1,
The heat generating surface of the light source is a distributed optical fiber temperature sensor in contact with the metal plate. The distributed optical fiber temperature sensor according to claim 1 or 2,
A distributed optical fiber temperature sensor in which a heat sink is disposed on the metal plate. A light source, an optical amplifier module for amplifying the light emitted from the light source, a temperature measuring optical fiber for measuring the temperature distribution by propagating the light emitted after being amplified by the optical amplifier module, and the temperature A distributed optical fiber temperature sensor having a Peltier module for heating a reference temperature section provided in a part of a measurement optical fiber and controlling the temperature,
The heat generating surface of the optical amplifier module and the heat absorbing surface of the Peltier module are in direct contact with each other, and the heat generating surface located on the side opposite to the heat absorbing surface of the Peltier module is in contact with the reference temperature portion.
A distributed optical fiber temperature sensor.

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