JP2015096806A - Transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure/pressure difference transmitter capable of ensuring detect accuracy against hydrogen entering from the outside or hydrogen and carbon hydride etc. generated inside.SOLUTION: In a pressure/pressure difference transmitter 40 in which a sealed liquid 80 for transmitting a pressure is sealed within a pressure guide conduit 60, a space is to be formed between a diaphragm 50 and a wall face of the main body. The pressure guide conduit 60 is connected to the wall face of the main body. A pressure received by the diaphragm 50 via the sealed liquid 80 sealed in the space and the pressure guide conduit is transmitted to a sensor 130. The pressure/pressure difference transmitter 40 contains at least the sealed liquid and is arranged to have a hydrogen absorbing storage material 90 for absorbing and storing hydrogen atom contained in the sealed liquid, on the wall face or in a part from the wall face to a sensor 130. An output circuit 120 is disposed being separated from the main body.

Description

The present invention relates to a transmission apparatus, and more particularly to a transmission apparatus suitable for measuring a pressure of a fluid or a pressure difference between two points in a radiation environment and transmitting a detection signal thereof.

  The transmission device transmits the pressure of the fluid received by the diaphragm to the sensor by the sealed liquid enclosed in the pressure guide path, and transmits the electrical signal detected by the sensor to the outside, and measures the absolute pressure. Some measure the differential pressure.

  These pressure / differential pressure transmitters are used in nuclear power plants, oil refining plants, and the like, and accuracy of, for example, ± 1% is required from the viewpoint of ensuring plant safety and product quality. However, it was difficult to maintain the accuracy for a long period of time due to the effect of hydrogen permeated from the outside of the pressure / differential pressure transmitter.

  That is, after a part of hydrogen (hydrogen molecule, hydrogen atom, hydrogen ion) contained in the measurement fluid permeates the diaphragm, it accumulates as bubbles in the sealed liquid filled in the pressure guiding path. The pressure inside the pressure guiding path rises, and the change in pressure applied to the diaphragm cannot be correctly transmitted to the sensor, resulting in a decrease in measurement accuracy.

For this reason, conventionally, as described in, for example, Japanese Patent Application Laid-Open No. 2005-114453, a hydrogen occlusion film is provided on the sealed liquid side of the diaphragm of the pressure receiving portion to suppress hydrogen that permeates the diaphragm from the outside.

JP 2005-114453 A

  On the other hand, transmission devices are often used in harsh environments such as nuclear power plants. For example, when it is used for measuring a pressure associated with a pressure vessel in a nuclear power plant or the like, it is exposed to strong radiation such as alpha rays generated in the nuclear power plant. Therefore, there has been a problem that a circuit using an electronic component such as a semiconductor in the transmission apparatus malfunctions.

In the above prior art, hydrogen that permeates the diaphragm from the outside is suppressed, and only measures against hydrogen permeation from the outside are taken, and hydrogen or hydrocarbons generated inside or permeate. Hydrogen was not considered. In the case where hydrogen or hydrocarbons are generated due to decomposition by radiation or heat, the encapsulated liquid filled in the pressure guiding path accumulates in the encapsulated liquid and bubbles when it exceeds a certain amount. For this reason, the pressure inside the pressure guiding path of the transmitter rises, and there is a problem that the accuracy of tolerance of the pressure / differential pressure transmitter (for example, accuracy of ± 1%) cannot be maintained.

The present invention has been made in order to solve the above-described problems, and its purpose is to prevent deterioration of normal pressure measurement accuracy even when the transmission device is exposed to radiation, and to prevent hydrogen or carbonization. An object of the present invention is to provide a transmission apparatus that can maintain detection accuracy against hydrogen.

In order to solve the above-described problems, the present invention has a diaphragm and a pressure receiving chamber wall surface, and forms a space between the diaphragm and the pressure receiving chamber wall surface, and is connected to the pressure receiving chamber wall surface. A pressure or differential pressure having a pressure guiding path, and transmitting the pressure received by the diaphragm to the sensor via the space and the sealed liquid sealed in the pressure guiding path, and sending the output of the sensor to an output circuit; In the pressure transmission device, at least a part of the sealed liquid, the pressure receiving chamber wall surface or the pressure receiving chamber wall surface to the sensor is provided with a hydrogen storage material that stores hydrogen atoms of the sealed liquid, and the output circuit is isolated from the main body. Thus, a shielding wall is provided between the sensor and the output circuit.

According to the present invention, it is possible to maintain detection accuracy even under high radiation.

1 is an overall configuration diagram of a pressure / differential pressure transmitter according to an embodiment of the present invention. It is explanatory drawing of the differential pressure transmitter in the pressure / differential pressure transmitter which concerns on 1st Embodiment. It is explanatory drawing of a pressure transmitter. It is explanatory drawing which shows the hydrogen storage method by a hydrogen storage material. It is explanatory drawing which shows the method of occluding the hydrogen of the sealing liquid radiolyzed by the hydrogen storage material. It is explanatory drawing which shows the hydrogen atom storage method in hydrocarbons by a hydrogen storage material.

  The best mode for carrying out the present invention will be described below. The pressure / differential pressure transmitter according to the first embodiment will now be described in detail with reference to FIGS.

  FIG. 1 is an overall configuration diagram. The nuclear power plant includes a nuclear reactor 1, a high-pressure turbine, a low-pressure turbine, a feed water heater, a moisture separation heater, a drain tank, a condenser (not shown), and the like. The drain tank 1 is a facility for storing drain water of a feed water heater or a moisture separator heater. The differential pressure transmitter 40 is provided, for example, for measuring a differential pressure between a predetermined gas side 2 and a liquid side 3 in the drain tank 1. The feed water heater, the moisture separator heater and the drain tank thereof are primary systems, and the environment has a high radiation dose.

  The differential pressure transmitter 40 receives pressure by the pressure receiving diaphragm 50 and is filled with an intermediate diaphragm 70 (shown in FIG. 2) by an enclosed liquid 80 (shown in FIG. 2) enclosed in a pressure guiding path 60 (shown in FIG. 2). ), Pressure is transmitted to the sensor 130 through the seal diaphragm 100 (shown in FIG. 2) and the center diaphragm 110 (shown in FIG. 2). The pressure received by the sensor 130 is input to the output circuit 120 and a pressure value is output.

  The output circuit 120 can be installed in an environment where the radiation dose and temperature are low by, for example, a shielding wall 170 that shields radiation between the output circuit 120 and the sensor 130, and the differential pressure transmitter is allowed by the influence of radiation and heat. It is possible to prevent deviation from error accuracy.

  FIG. 2 is an explanatory diagram of the differential pressure transmitter in the pressure / differential pressure transmitter according to the first embodiment of the present invention.

  In FIG. 2, the differential pressure transmitter 40 for measuring the differential pressure includes a replacer unit 10, a capillary unit 20, and a main body unit 30. The pressure of the measurement fluid 140 is received by the two pressure receiving diaphragms 50, and the pressure is transmitted to the sensor 130 via the intermediate diaphragm 70, the seal diaphragm 100, and the center diaphragm 110 by the sealed liquid 80 sealed in the pressure guiding path 60. The pressure received by the sensor 130 is input to the output circuit 120 and a pressure value is output.

  In the figure, the intermediate diaphragm 70 is provided between the pressure-receiving diaphragm 50 and the seal diaphragm 100. However, a plurality of intermediate diaphragms 70 may be provided, and the filled liquid may be sealed between the plurality of intermediate diaphragms 70.

  Here, the displacement portion 10 will be described. The pressure receiving chamber 52 is formed by being surrounded by the pressure receiving diaphragm 50 and the pressure receiving chamber wall surface 51. The pressure of the measurement fluid 140 is first received by the pressure receiving diaphragm 50, and It is transmitted to the sealed liquid stored in the pressure receiving chamber 52, and further transmitted to the sealed liquid in the pressure guiding path 60.

    Although not described in detail, the concept that the pressure receiving chamber is formed by the diaphragm and the pressure receiving chamber wall surface of the pressure receiving diaphragm 50 is also applied to the intermediate diaphragm 70 and the seal diaphragm 100.

  In the above-described configuration, not only between the pressure receiving diaphragm 50 and the intermediate diaphragm 70 but also the portions where the sealing liquid between the intermediate diaphragm 70, the seal diaphragm 100, the center diaphragm 110, and the sensor 130 is sealed is all at the pressure guiding path 60. It is.

  In the above configuration, hydrogen permeated from the outside of the differential pressure transmitter 40 is bubbled in the sealed liquid, whereby the internal pressure of the pressure guiding path 60 is increased, and the change in pressure applied to the pressure receiving diaphragm 50 can be correctly transmitted to the sensor 130. It is known that the measurement accuracy will be lost. Specifically, the pressure value varies from the normal value when the amount of gas bubbled inside the pressure guiding path 60 on the high pressure side 150 and the low pressure side 160 is different.

  Furthermore, even if hydrogen and hydrocarbons are generated and bubbled due to radiolysis or thermal decomposition of the sealing liquid, the pressure inside the pressure guiding path 60 increases and the detection accuracy of the sensor 130 decreases. Was found as a new issue. The hydrocarbons include methane, ethane, propane and the like.

  These hydrogen permeated from the outside, or hydrogen and hydrocarbons generated inside, are bubbled when the amount of the filled liquid 80 inside the pressure guiding path 60 is exceeded. Furthermore, the closer the pressure of the measuring object of the transmission device is to a vacuum, the more the amount of dissolution becomes.

  In the above-described configuration, the differential pressure transmitter 40 encloses or introduces both hydrogen permeated from the outside of the differential pressure transmitter 40 or hydrogen generated inside and hydrogen atoms in hydrocarbons inside the pressure guiding path 60. Occlusion by the hydrogen occlusion material 90 applied to the inner wall surface 60 can prevent an increase in pressure inside the pressure guiding path 60 due to accumulation of hydrogen and hydrocarbons as bubbles. Here, the pressure guiding path 60 refers to a portion in which the sealing liquid 80 between the two pressure receiving diaphragms 50 is sealed, and is shown darkly in FIG.

  With the above configuration, the influence of hydrogen permeated from the outside and the influence of hydrogen and hydrocarbons generated internally due to the influence of radiation and heat can be reduced. It deviates from accuracy (for example, accuracy of ± 1%).

  For this reason, the radiation amount and temperature of the output circuit 120 are more than that of the installation environment of the main body 30 by, for example, a shielding wall 170 that shields radiation between the output circuit 120 of the differential pressure transmitter 40 and the main body 30. It can be installed in a low environment, and the differential pressure transmitter can be prevented from deviating from the tolerance accuracy due to the influence of radiation and heat.

  The method of installing the output circuit 120 in an environment where the radiation dose or temperature is lower than the installation environment of the main body 30 may be installed to cover the outside of the output circuit 120 with a shield, for example, The output circuit 120 may be simply moved away from the main body 30.

  FIG. 3 is an explanatory diagram of the pressure transmitter. In FIG. 2, the pressure transmitter 200 for measuring the absolute pressure receives the pressure of the measurement fluid 140 by the pressure receiving diaphragm 50, and the pressure is transmitted to the sensor 130 by the sealed liquid 80 sealed in the pressure guiding path 60. . The pressure received by the sensor 130 is input to the output circuit 120 and output as a pressure value.

  In the above configuration, as in FIG. 2, when the hydrogen transmitted from the outside of the pressure transmitter 200 or the hydrogen and hydrocarbons generated inside the pressure transmitter 200 are bubbled, the pressure transmitter 200 causes the pressure inside the pressure guide path 60 to be a normal value. It will fluctuate. Here, as in FIG. 2, both hydrogen and hydrogen atoms in the hydrocarbons are occluded by the hydrogen occlusion material 90 enclosed in the pressure guiding path 60 or applied to the inner wall surface of the pressure guiding path 60, thereby hydrogen and carbonization. It is possible to prevent an increase in pressure inside the pressure guiding path 60 due to bubbling of hydrogen. Furthermore, the influence which the output circuit 120 receives from a radiation and temperature can be reduced by keeping the output circuit 120 away from the main-body part 30. FIG.

  FIG. 4 shows the hydrogen storage effect of the hydrogen storage material. FIG. 4 shows an image diagram of hydrogen storage of palladium as an example of the hydrogen storage material 90. The hydrogen storage material 90 may be magnesium, vanadium, titanium, manganese, zirconium, nickel, niobium, cobalt, calcium, or an alloy thereof other than palladium.

  Palladium has a face-centered cubic lattice, and the hydrogen molecules 300 are occluded as hydrogen atoms 310 between the palladium atoms 320. It is known that palladium occludes 935 times its own volume of hydrogen.

  FIG. 5 shows an explanatory diagram of a method for storing hydrogen in the sealing liquid 80 that has been radiolyzed with a hydrogen storage material. In FIG. 5, methane 362 and hydrogen molecules 360 will be described as an example. In the sealing liquid 80, the bond between C and H in the composition formula 330 of the sealing liquid or the bond between Si and C is broken by radiation such as gamma rays 340. When the hydrogen storage material is not used, the methyl group 360 and the hydrogen atom 361 generated thereby are combined with each other to form hydrocarbons such as methane 362 and hydrogen molecules 360.

  On the other hand, in the case of using a hydrogen storage material, hydrogen atoms 361 generated by radiolysis are stored in the hydrogen storage material 90, so that the amount of methyl groups 360 bonded to the hydrogen atoms 361 decreases, so that methane 362 is generated. The amount can be suppressed. The methyl group 360 that is not bonded to the hydrogen atom 361 returns to the sealing liquid again. Thereby, the pressure rise inside the pressure guide path 60 due to accumulation of hydrocarbons such as methane 362 as bubbles can be prevented.

  Alternatively, FIG. 5 shows an explanatory diagram as a technique for storing hydrogen atoms in hydrocarbons with a hydrogen storage material. In FIG. 6, methane 362 is described as an example. A part of the methyl group 360 and the hydrogen atom 361 generated by radiolysis are combined with each other to become methane 362. Thereafter, when the methane 362 comes into contact with the surface of the hydrogen storage material 90, it dissociates into a methyl group 360 and a hydrogen atom 361. The hydrogen atoms 361 are occluded by the hydrogen occlusion material 90, and the methyl groups 360 are finally converted to carbon atoms and adsorbed on the surface of the hydrogen occlusion material. Thereby, the pressure rise inside the pressure guide path 60 due to accumulation of hydrocarbons such as methane 362 as bubbles can be prevented.

By installing such a hydrogen storage material 90 inside or on the wall surface of the pressure / differential pressure transmitter 60, hydrogen permeated from the outside of the pressure / differential pressure transmitter or hydrogen and hydrocarbons generated therein. Since the hydrogen atoms therein can be occluded up to 935 times its own volume, it is possible to suppress an increase in internal pressure due to bubbling of hydrogen and hydrocarbons inside the pressure guiding path.

DESCRIPTION OF SYMBOLS 10 Displacer part 20 Capillary part 30 Main body part 40 Differential pressure transmitter 50 Pressure receiving diaphragm 51 Pressure receiving wall surface 52 Pressure receiving room 60 Pressure guiding path 70 Middle diaphragm 80 Filling liquid 90 Hydrogen storage material 100 Sealing diaphragm 110 Center diaphragm 120 Output part 130 Sensor 140 Measurement fluid 150 High pressure side 160 Low pressure side 170 Shielding wall 200 Pressure transmitter 300 Hydrogen molecule 310 Hydrogen atom 320 Palladium atom 330 Filling liquid composition formula 340 Gamma ray 350 When hydrogen storage material is not used 351 When hydrogen storage material is used 360 Methyl Group 361 hydrogen atom 362 methane

Claims (8)

  A diaphragm, a pressure receiving chamber wall surface, forming a space between the diaphragm and the pressure receiving chamber wall surface, and having a pressure guiding path connected to the pressure receiving chamber wall surface; In the pressure or differential pressure transmission device that transmits the pressure received by the diaphragm to the sensor through the sealed liquid sealed in the pressure guiding path, and sends the output of the sensor to an output circuit, at least the sealed liquid, A hydrogen storage material for storing hydrogen atoms of the sealed liquid is provided in the pressure receiving chamber wall surface or a part from the pressure receiving chamber wall surface to the sensor, and the output circuit is isolated from the main body, and between the sensor and the output circuit. A transmission apparatus characterized by providing a shielding wall.   2. The transmission device according to claim 1, wherein hydrogen that has entered from the outside of the transmission device or hydrogen atoms generated inside is stored in the hydrogen storage material.   2. The transmission apparatus according to claim 1, wherein the hydrogen storage material is palladium, magnesium, vanadium, titanium, manganese, zirconium, nickel, niobium, cobalt, calcium, or an alloy thereof.   2. The transmission apparatus according to claim 1, wherein the output circuit is installed in an environment lower than the radiation dose and temperature of the main body by isolating the output circuit from the main body.   2. The transmission apparatus according to claim 1, wherein a shielding wall capable of shielding radiation or a shielding body covering the output circuit is provided between the output circuit and the main body.   2. The diaphragm according to claim 1, wherein the diaphragm is configured as a first diaphragm that receives a pressure of a measurement fluid, and a second diaphragm that receives a pressure from the first diaphragm, and the sealing liquid is the first diaphragm. The hydrogen occlusion material is configured to transmit the pressure received and the pressure received by the second diaphragm, and the hydrogen storage material includes the inside of the pressure guiding path, the pressure guiding path wall surface, and the main body side of the first diaphragm. A transmission device, characterized in that it is provided as a wall surface, the liquid side of the first diaphragm, the second diaphragm, or a combination thereof.   In Claim 1, the third diaphragm and the fourth diaphragm are provided in the middle of the first diaphragm and the second diaphragm, and the portion provided with the hydrogen storage material, the pressure receiving side of the third diaphragm, A transmission device characterized in that the third diaphragm is either a sealed liquid side, a pressure receiving side of the fourth diaphragm or a sealed liquid side of the fourth diaphragm, or a combination thereof.   The wire hydrogen storage material, the plate-shaped hydrogen storage material, or the solid hydrogen storage material as a hydrogen storage material is enclosed in or attached to the inside of the pressure guiding path according to claim 1, or both. Transmission equipment.