JP5999937B2 - Vibration evaluation device - Google Patents

Description

  The present invention relates to a vibration evaluation apparatus that evaluates vibration due to low-frequency component sound emitted from an exhaust chimney that discharges exhaust gas from a gas turbine, for example.

  A general gas turbine includes a compressor, a combustor, and a turbine. Then, the air taken in from the intake duct is compressed by the compressor to become high-temperature and high-pressure compressed air, and in the combustor, fuel is supplied to the compressed air and burned to thereby generate high-temperature and high-pressure air. A combustion gas (working fluid) is obtained, a turbine is driven by the combustion gas, and a generator connected to the turbine is driven.

  Such an exhaust chimney that exhausts the exhaust gas of the gas turbine may emit sound having a low frequency component of several Hz or less to the outside due to resonance of the sound field inside the gas turbine. For example, low frequency components often have frequencies below the human audible sound, so there is little direct noise, but indirectly the vibrations (backlash) of the furniture (such as windows) around the plant. It may be a factor to cause.

  In order to reduce the possibility of emitting such specific low-frequency component sound to the outside, there is a silencer (silencer) technique (see Patent Document 1).

JP-A-11-159347

  The silencer of the exhaust flue of Patent Document 1 described above can mute the sound of low frequency components. However, in order to evaluate the silencing effect, an evaluation device that evaluates rattling itself such as a window frame of a house is desired.

  This invention solves the subject mentioned above, and aims at providing the vibration evaluation apparatus which indirectly evaluates the sound of a low frequency component as a vibration of a test body.

Instrument order to achieve the above object, the vibration evaluation device, which emits an acoustic room closed space sound of the following frequency components audible sound is amplified by resonance, the sound of the frequency components in the acoustic room And a test body that is disposed in the acoustic room and is a target for examining the influence of vibration generated by the sound of the frequency, and a sensor that detects the vibration generated in the test body, To do.

  With the above-described configuration, the vibration evaluation apparatus can evaluate the evaluation of a low frequency sound below the audible sound as an indirect vibration of the specimen.

  In the present invention, the inner wall of the acoustic room preferably includes a sound absorbing material.

  With the above configuration, the vibration evaluation apparatus can widen the apparent closed space of the acoustic room. For this reason, the vibration evaluation apparatus can reduce the acoustic room.

  In this invention, the said test body is a window and a window frame, Comprising: It is arrange | positioned in the said acoustic room by the support member which supports the said window frame, The said support member is the fastening torque which changes the fastening state of the said window frame It is preferable that a change means is provided.

  By the said structure, the space | interval which vibrates the window used as the play of a window and a window frame is suppressed or eased. For this reason, the vibration evaluation apparatus can simulate the state of joinery that differs depending on the house.

  In the present invention, the acoustic room is preferably a closed space in which at least one of length, width, and height is different from the other lengths and resonates at a plurality of different resonance frequencies.

  With the above configuration, the vibration evaluation apparatus can form a closed space that resonates at a plurality of resonance frequencies in an acoustic room. For this reason, the vibration evaluation apparatus can reproduce the resonance frequency of a more complicated sound field.

  ADVANTAGE OF THE INVENTION According to this invention, the vibration evaluation apparatus which indirectly evaluates the sound of a low frequency component as a vibration of a test body can be provided.

FIG. 1 is a schematic configuration diagram illustrating a vibration evaluation apparatus according to the embodiment. Drawing 2 is a mimetic diagram showing typically the support member of an embodiment. FIG. 3 is a block diagram schematically showing the measurement system. FIG. 4 is an explanatory diagram for explaining the acoustic room of the embodiment. FIG. 5 is an explanatory diagram for explaining the acoustic room of the embodiment.

  DESCRIPTION OF EMBODIMENTS Embodiments (embodiments) for carrying out the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by this embodiment. The constituent elements described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the constituent elements described below can be appropriately combined.

  FIG. 1 is a schematic configuration diagram illustrating a vibration evaluation apparatus according to the embodiment. The vibration evaluation apparatus 1 includes an acoustic room 2, a sound source 3, a test body W, and sensors SH, SM, and SL that detect vibration. The sensors SH, SM, and SL that detect vibration constitute the measurement system 4 together with the vibration analysis device 42 and the computer 41, for example.

  A general gas turbine includes a compressor, a combustor, and a turbine. Then, the air taken in from the air duct is compressed by the compressor to become high-temperature and high-pressure compressed air. In the combustor, fuel is supplied to the compressed air and burned, and the high-temperature and high-pressure air is burned. A combustion gas (working fluid) is obtained, a turbine is driven by the combustion gas, and a generator connected to the turbine is driven.

  Such an exhaust chimney that exhausts the exhaust gas of the gas turbine may emit sound having a low frequency component of several Hz or less to the outside due to resonance of the sound field inside the gas turbine. For example, the sound of the low frequency component is several tens Hz or less. This low frequency component sound is often a frequency component below human audible sound (frequency of 20 Hz or less), so that it is less likely to feel an abnormal noise directly, but indirectly a house fixture around the plant, for example, It may be a factor that causes vibration (rattle) of windows and window frames.

  The vibration evaluation apparatus 1 according to the embodiment can simulate a state in which low-frequency component sounds cause vibrations (backlashes) of furniture of houses around the plant, such as windows and window frames. In order to generate the sound of this low frequency component, the sound source 3 includes, for example, an oscillator 31, an amplifier 32, and a speaker 33. The sound source 3 oscillates a signal having the same frequency component as the low-frequency component sound emitted from the exhaust chimney from which the oscillator 31 discharges the exhaust gas of the gas turbine, amplifies this signal by the amplifier 32, and outputs it to the speaker 33. . And the speaker 33 emits the sound of a low frequency component into the inside of the acoustic room 2. FIG.

  The acoustic room 2 constitutes a closed space that resonates with a frequency component below the human audible sound. For this reason, any one of vertical Y, horizontal X, and height Z needs to have a length having a resonance frequency that resonates with a low frequency component equal to or lower than the audible sound to be evaluated. When an acoustic length having a resonance frequency that resonates with a low frequency component less than or equal to the audible sound to be evaluated is L, L is a length represented by Expression (1). Here, c is the speed of sound waves (for example, 340 m / s), and f is the resonance frequency.

  L = c / 4f (1)

  For example, when the resonance frequency is 2 Hz, the acoustic length L is 42.5 m. Therefore, in the acoustic room 2 of the embodiment, for example, by setting the lateral length X to the acoustic length L, the acoustic room 2 can constitute a closed space that resonates with a frequency component less than or equal to the audible sound. In the acoustic room 2 of the embodiment, the lateral length Y may be the acoustic length L, and the height Z may be the acoustic length L.

  Inside the acoustic room 2, a window WG and a window frame WU of the window WG are supported by a support member 5 as a test body W. Drawing 2 is a mimetic diagram showing typically the support member of an embodiment. As shown in FIG. 2, the support member 5 is a support column 51, a mount 52 attached to the support column 51, and a mounting bolt 53 that positions the window frame WU that is the test body W on the mount 52.

  The mounting base 52 and the mounting bolt 53 have a fastening structure that constitutes a fastening torque changing means. For example, the tightening torque changing means is an internal thread of the mounting base 52 and an external thread of the mounting bolt 53 that is screwed into the internal thread. With this structure, the tightening state of the window frame WU can be changed. For this reason, the vibration evaluation apparatus 1 can evaluate the vibration which arises in the window frame WU and the window WG by changing the boundary condition of the window frame WU which is a different fitting for each house. The tightening torque changing unit may be a mechanism that applies a pressing force to the window frame WU, and may be an actuator that drives and presses an electric motor, for example.

  Sensors SH, SM, and SL that can detect vibration are attached to the test body W. In the vibration evaluation apparatus 1 according to the embodiment, the height at which the plurality of sensors SH, SM, and SL are attached to the test body W is changed. The vibration detection accuracy can be increased by attaching the plurality of sensors SH, SM, and SL at different heights. One sensor may be used.

  As the sensors SH, SM, and SL, an acceleration sensor, a microphone, or the like can be used. The sensors SH, SM, and SL are electrically connected to the vibration analysis device 42 and send electric signals to the vibration analysis device 42 according to the vibration of the test body W. The vibration analysis device 42 performs primary processing for analyzing the electrical signals of the sensors SH, SM, and SL, for example, for each frequency domain. FIG. 3 is a block diagram schematically showing the measurement system. As shown in FIG. 3, the vibration analysis device 42 sends vibration analysis information is to the computer 41.

  The computer 41 includes an input processing circuit 81, an input port 82, a processing unit 90, a storage unit 94, an output port 83, and an output processing circuit 84. The processing unit 90 includes, for example, a CPU (Central Processing Unit) 91, a RAM (Random Access Memory) 92, and a ROM (Read Only Memory) 93. A display device 85 and an input device 86 can be connected to the computer 41 as necessary. The computer 41 can operate without the input device 86.

  The processing unit 90, the storage unit 94, and the input port 82 and the output port 83 are connected via a bus 87, a bus 88, and a bus 89. By the bus 87, the bus 88, and the bus 89, the CPU 91 of the processing unit 90 is configured to exchange control data with the storage unit 94, the input port 82, and the output port 83 and to issue commands to one side. The

  An input processing circuit 81 is connected to the input port 82. For example, the above-described vibration analysis information is is connected to the input processing circuit 81. The vibration analysis information is is converted into a signal that can be used by the processing unit 90 by a noise filter, an A / D converter, or the like provided in the input processing circuit 81 and then sent to the processing unit 90 via the input port 82. . Thereby, the processing unit 90 can acquire necessary information.

  An output processing circuit 84 is connected to the output port 83. The output processing circuit 84 is connected to a display device 85 and an external output terminal. The output processing circuit 84 includes a display device control circuit, a signal amplifier circuit, and the like. The output processing circuit 84 outputs the vibration characteristics calculated by the processing unit 90 to the display device 85. As the display device 85, for example, a liquid crystal display panel, a CRT (Cathode Ray Tube), or the like can be used.

  The storage unit 94 stores a computer program including an operation procedure of the measurement system. Here, the storage unit 94 can be configured by a volatile memory such as a RAM, a nonvolatile memory such as a flash memory, a hard disk drive, or a combination thereof.

  The computer program may execute an operation procedure of the measurement system in combination with a computer program already recorded in the processing unit 90. Further, the computer 41 may execute an operation procedure using dedicated hardware instead of the computer program.

  FIG.4 and FIG.5 is explanatory drawing for demonstrating the acoustic room of embodiment. As shown in FIGS. 4 and 5, a sound absorbing material 20 is attached to the inner wall of the acoustic room 2. The sound absorbing material 20 is, for example, glass wool or rock wool. The sound absorbing material 20 forms a so-called acoustic impedance boundary because the acoustic particle velocity does not become zero at the wall of the acoustic room 2. Thereby, the apparent space in the acoustic room 2 can be made wider than the actual space. For this reason, the acoustic length L mentioned above can be shortened. And the vibration evaluation apparatus 1 can make the acoustic room 2 small compared with the case where there is no sound-absorbing material 20.

  In addition, the acoustic room 2 may be a closed space in which at least one of the vertical Y, the horizontal X, and the height Z is different from the other lengths and resonates at different resonance frequencies. Alternatively, the acoustic room 2 can have different lengths of length Y, width X, and height Z. For example, the acoustic room 2 has an acoustic length that resonates at 2 Hz in the longitudinal Y length, an acoustic length that resonates at 1 Hz in the lateral X, and an acoustic length that resonates at 3 Hz in the height Z. It is possible to form a closed space that is different at a 1 Hz pitch and resonates at a plurality of resonance frequencies. For this reason, the vibration evaluation apparatus 1 according to the embodiment can reproduce the resonance frequency of a more complicated sound field. In addition, the acoustic room 2 is good also as the length Y, width X, and height Z all being the same.

  Moreover, in the acoustic room 2, it is more preferable to arrange the test body W closer to the wall. With this arrangement, the position of the specimen W becomes closer to the node of the standing wave of the resonance frequency in the acoustic room 2. As a result, the vibration acting on the test body W is increased, so that the speaker 33 having a small rated output can be used.

  The vibration evaluation apparatus 1 according to the embodiment includes an acoustic room 2, a sound source 3, a test body W, and sensors SH, SM, and SL. The acoustic room 2 is a closed space that resonates with a frequency component below the audible sound. The sound source 3 radiates sound into the acoustic room 2. The test body W is a target for examining the influence of vibration due to the sound of the frequency component in the acoustic room 2. Sensors SH, SM, and SL detect vibration generated in the test body W.

  In the vibration evaluation apparatus 1 according to the embodiment, the sound source 3 emits a sound having a low frequency component to the acoustic room 2. The sound of the low frequency component emitted from the sound source 3 resonates in the acoustic room 2 and is amplified. For this reason, even if the output of the sound source 3 is small, it can be evaluated. The amplified low frequency component sound acts on the specimen W. When the sound of the low frequency component emitted by the sound source 3 or the sound of the higher order frequency component of the sound of the low frequency component matches the natural vibration frequency of the window WG of the test object W, the window WG shakes. Although the window WG is supported by the window frame WU, there is play, so the window WG and the window frame WU come into contact with each other to generate a backlash, and generate a vibration sound accompanying the vibration of the window WG.

  The tightening torque changing means is a mechanism that applies a pressing force to the window frame WU, and changes the tightening state of the window frame WU by changing the tightening position of the mounting bolt 53, for example. By the tightening torque changing means, the vibration interval of the window WG that becomes play between the window WG and the window frame WU is suppressed or alleviated. For this reason, the vibration evaluation apparatus 1 according to the embodiment can simulate the state of fittings (window WG and window frame WU) that differ depending on the house.

  The sensors SH, SM, and SL output an electrical signal to the vibration analyzer 42 according to the vibration. The vibration analysis device 42 sends vibration analysis information is to the computer 41. The computer 41 displays the vibration evaluation result on the display device 85 to the evaluator. For example, the computer 41 can store in the storage unit 94 the vibration of the test body W for each tightening state of the window frame WU changed by the tightening torque changing means. As described above, the vibration evaluation apparatus 1 according to the embodiment can indirectly evaluate the sound of the low frequency component as the vibration of the test body W.

  Moreover, although the vibration evaluation apparatus according to the above-described embodiment has been applied to a gas turbine, the present invention is not limited to a gas turbine, and is applicable to any equipment as long as it emits sound having a frequency component below an audible sound. It is possible.

DESCRIPTION OF SYMBOLS 1 Vibration evaluation apparatus 2 Sound room 3 Sound source 4 Measurement system 5 Support member 20 Sound absorption material 31 Oscillator 32 Amplifier 33 Speaker 41 Computer 42 Vibration analysis apparatus 51 Support pillar 52 Mounting base 53 Mounting bolt 85 Display apparatus is Vibration analysis information SH, SM, SL sensor W specimen WG window WU window frame

Claims (4)

An acoustic room in a closed space in which sound with a frequency component below the audible sound is amplified by resonance,
A sound source that emits the sound of the frequency component in the acoustic room;
A test body that is placed in the acoustic room and is a target for examining the influence of vibration caused by the sound of the frequency;
A sensor for detecting the vibration generated in the specimen;
A vibration evaluation apparatus comprising:   The vibration evaluation apparatus according to claim 1, wherein an inner wall of the acoustic room includes a sound absorbing material. The test body is a window and a window frame, and is arranged in the acoustic room by a support member that supports the window frame,
The vibration evaluation apparatus according to claim 1, wherein the support member includes a tightening torque changing unit that changes a tightening state of the window frame.   4. The acoustic room is a closed space in which at least one of length, width, and height is different from other lengths and resonates at a plurality of different resonance frequencies. The vibration evaluation apparatus according to claim 1.

Images