JP2010256224A - Piping diagnosing device and air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a piping diagnosing device and an air conditioner, capable of detecting an abnormality of at least one of piping and a material disposed at the outer circumference of the piping, regardless of the presence or absence of contents in the piping. <P>SOLUTION: The device includes: a signal applying means 71 for applying a prescribed signal to conductive piping portions 5, 6; a signal detecting means 91 for detecting the prescribed signal propagated through the piping portions 5, 6; and an abnormality detecting means 92 for detecting the abnormality of at least one of the piping portions 5, 6 and heat insulating materials 501, 601 disposed at the outer circumferences of the piping portions on the basis of the prescribed signal detected by the signal detecting means 91. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a pipe diagnosis device that detects an abnormality in at least one of pipes and surrounding materials, and an air conditioner.

  Conventionally, as a technique for diagnosing deterioration of piping, for example, “an electromagnetic wave is incident on a pipe of a buried pipe installed in a certain medium, and the interaction between this electromagnetic wave and the buried pipe and its surrounding medium is measured. Then, an abnormality in the buried pipe and its surroundings is detected from the measured value of the interaction ”(for example, see Patent Document 1).

Japanese Patent No. 3400255 (paragraph number [0007])

  In the technique described in Patent Document 1, the pipe is used as a waveguide in a state where there is no content in the pipe, and the interaction between the incident electromagnetic wave and the pipe and the surrounding medium is measured. Abnormalities in the piping and its surroundings are detected from the measured values of action.

However, there is a problem that the abnormality of the pipe and its surrounding materials cannot be detected unless the substance in the pipe is removed.
For example, in an air conditioner, in order to detect an abnormality in a pipe that circulates refrigerant, it is necessary to remove the refrigerant in the pipe every time an abnormality is diagnosed. It is difficult to apply this technology. Further, it is impossible to detect an abnormality in the piping while the air conditioner is in operation.

  The present invention has been made to solve the above-described problems, and can detect an abnormality in at least one of a pipe and a material provided on the outer periphery of the pipe regardless of the presence or absence of contents in the pipe. A piping diagnostic device and an air conditioner that can be obtained are obtained.

The piping diagnostic apparatus according to the present invention is
A signal applying means for applying a predetermined signal to the conductive pipe;
Signal detection means for detecting the predetermined signal propagated through the pipe;
And an abnormality detecting means for detecting the presence or absence of an abnormality in at least one of the pipe and the material provided on the outer periphery of the pipe based on the predetermined signal detected by the signal detecting means.

The air conditioner according to the present invention is
Indoor unit,
Outdoor unit,
A refrigerant pipe configured to provide a heat insulating material on the outer periphery of the conductive pipe, and circulate a refrigerant in the indoor unit and the outdoor unit;
The above-described piping diagnostic device is provided.

  Since the present invention detects whether or not there is an abnormality in at least one of the pipe and the material provided on the outer periphery of the pipe based on a predetermined signal propagated through the pipe, the pipe and the pipe regardless of the presence or absence of contents in the pipe An abnormality of at least one of the materials provided on the outer periphery can be detected.

It is a figure which shows the structure of the air conditioner and piping diagnostic apparatus which concern on Embodiment 1. FIG. 1 is a diagram illustrating a configuration of a diagnostic device according to Embodiment 1. FIG. 6 is a diagram showing gain-frequency characteristics in a normal state according to Embodiment 1. FIG. It is a figure which shows the dielectric constant of piping in the normal state which concerns on Embodiment 1. FIG. It is a figure which shows the dielectric constant of piping in the deterioration state which concerns on Embodiment 1. FIG. 6 is a diagram showing gain-frequency characteristics in a deteriorated state according to Embodiment 1. FIG. It is a figure which shows the structure of the air conditioner and piping diagnostic apparatus which concern on Embodiment 2. FIG. It is a figure which shows the structure of the diagnostic apparatus which concerns on Embodiment 2. FIG. It is the figure which showed typically the impedance of piping in the normal state which concerns on Embodiment 2. FIG. It is a figure which shows the impedance model in the normal state which concerns on Embodiment 2. FIG. It is the figure which showed typically the impedance of piping in the deterioration state which concerns on Embodiment 2. FIG. It is a figure which shows the impedance model in the degradation state which concerns on Embodiment 2. FIG. It is a figure which shows the pulse waveform which concerns on Embodiment 2, and the transmission point waveform at the time of normal and deterioration.

Embodiment 1 FIG.
<Configuration>
FIG. 1 is a diagram showing a configuration of an air conditioner and a piping diagnostic device according to Embodiment 1.
As shown in FIG. 1, the air conditioner includes an outdoor unit 1, an indoor unit a2, an indoor unit b3, an indoor unit c4, a pipe 5, and a pipe 6.
Further, the piping diagnostic device in the present embodiment includes a diagnostic device 7 and a diagnostic device 9.

  In the present embodiment, a case where one outdoor unit 1 and three indoor units a2, b3, and c4 are provided will be described. However, the present invention is not limited thereto, and the outdoor unit and the indoor unit are provided. Any number may be provided.

The outdoor unit 1 and the indoor units a2, b3, and c4 are connected by pipes 5 and 6.
The outdoor unit 1, the indoor unit a <b> 2, the indoor unit b <b> 3, and the indoor unit c <b> 4 change the pressure of the refrigerant flowing in the pipes 5 and 6 and perform air conditioning by heat absorption and heat dissipation of the refrigerant.
The outdoor unit 1 includes a compressor (not shown) that compresses the refrigerant, an outdoor heat exchanger (refrigerant circuit) (not shown) in which the refrigerant exchanges heat with the outside air, and the like. The outdoor unit 1 is installed outdoors, for example, and is arranged on the rooftop of a building.
The indoor units a2, b3, and c4 are not shown in the drawings, and the refrigerant sent from the outdoor unit 1 sends out the heat exchanged indoors with an indoor heat exchanger (refrigerant circuit) (not shown) in which heat is exchanged with indoor air. It is configured to include a blower and the like. The indoor units a2, b3, and c4 are incorporated into the indoor ceiling, for example.

The pipes 5 and 6 are adapted to conduct refrigerant (carbon dioxide, chlorofluorocarbon, etc.).
The pipes 5 and 6 are made of, for example, a metal material such as copper and have conductivity.
The outer periphery of the pipe 5 is covered with a heat insulating material 501 made of an insulating material such as urethane foam (see FIG. 4). The outer periphery of the pipe 6 is covered with a heat insulating material 601 made of an insulating material such as urethane foam (see FIG. 4).
By the heat insulating materials 501 and 601, the pipe 5 and the pipe 6 are constructed so as not to come into direct contact with air and to cause condensation.

  The heat insulating materials 501 and 601 correspond to the “material provided on the outer periphery of the pipe” in the present invention.

As shown in FIG. 1, the pipe 5 includes a main pipe 50, a branch pipe 51, and a branch pipe 52. The pipe 6 includes a main pipe 60, a branch pipe 61, and a branch pipe 62.
The main pipe 50 connects the outdoor unit 1 and the indoor unit c4.
The branch pipe 51 branches from the main pipe 50 and is connected to the indoor unit a2.
The branch pipe 52 branches from the main pipe 50 and is connected to the indoor unit b3.
The main pipe 60 connects the outdoor unit 1 and the indoor unit c4.
The branch pipe 61 branches from the main pipe 60 and is connected to the indoor unit a2.
The branch pipe 62 branches from the main pipe 60 and is connected to the indoor unit b3.

In the present embodiment, the case where the lengths of the main pipes 50 and 60 are 120 m and the lengths of the branch pipes 51, 52, 61, and 62 are each 20 m will be described as an example.
In addition, the length of each piping is not restricted to this, It can be set as arbitrary length.

Impedance uppers 81 for separating the pipes 5 and 6 from the outdoor unit 1 in an AC manner are provided at the connection portions 8 to which the outdoor unit 1 and the main pipes 50 and 60 are connected.
The impedance upper 81 is composed of a farite core, for example, and has an induction characteristic for a high-frequency signal. The impedance upper 81 separates the pipe 5 and the pipe 6 with a predetermined impedance in a high-frequency signal band.
The impedance upper 81 is preferably attached in the vicinity of the outdoor unit 1 of the pipe 5 and the pipe 6.

Impedance uppers 11 that separate the pipes 5 and 6 from the indoor unit c4 in an alternating manner are provided at the connection portions 10 to which the indoor unit c4 and the main pipes 50 and 60 are connected.
The impedance upper 11 is composed of, for example, a ferrite core and has induction characteristics for high-frequency signals. The impedance upper 11 separates the pipe 5 and the pipe 6 with a predetermined impedance in the high-frequency signal band.
It is desirable to install the impedance upper 11 in the vicinity of the indoor unit 4 c of the pipe 5 and the pipe 6.

  The diagnostic device 7 is connected to one end of the pipes 5 and 6 separated in an AC manner by the impedance upper 81. The diagnostic device 7 is preferably connected to the pipes 5 and 6 in the vicinity of the connecting portion 8.

  The diagnostic device 9 is connected to one end of the pipes 5 and 6 separated in an AC manner by the impedance upper 11. The diagnostic device 9 is preferably connected to the pipes 5 and 6 in the vicinity of the connecting portion 10.

The diagnostic device 7 generates a predetermined signal and applies the predetermined signal to the pipes 5 and 6.
Accordingly, the predetermined signal propagates between the pipe 5 and the pipe 6 having conductivity through the connection portion 8 using the pipe surface layer as a conductor.
The predetermined signal that has propagated is acquired by the diagnostic device 9 via the connection unit 10.
And the diagnostic apparatus 9 measures the frequency characteristic of the acquired predetermined signal. Based on this frequency characteristic, the diagnostic device 9 detects the presence / absence of an abnormality such as a deterioration state in at least one of the pipes 5 and 6 and the heat insulating materials 501 and 601. Details will be described later.

  Next, the configuration of the diagnostic device 7 and the diagnostic device 9 will be described.

FIG. 2 is a diagram illustrating a configuration of the diagnostic apparatus according to the first embodiment.
As shown in FIG. 2, the diagnostic device 7 includes a signal applying unit 71.
The diagnostic device 9 includes a signal detection unit 91, an abnormality detection unit 92, a storage unit 93, and a monitoring unit 94.

  The storage unit 93 corresponds to the “first storage unit”, the “second storage unit”, and the “third storage unit” in the present invention.

The signal applying means 71 applies a predetermined signal to the conductive pipes 5 and 6.
The signal applying means 71 applies a high frequency signal having a predetermined amplitude and a predetermined frequency band to the pipes 5 and 6 as a predetermined signal.
In this embodiment, a case where a high-frequency signal having a band of 1 MHz to 10 MHz is applied will be described.
However, the present invention is not limited to this, and the signal applying unit 71 may apply a high frequency signal having a predetermined amplitude as a predetermined signal to the pipes 5 and 6 by sweeping in a predetermined frequency range.

The signal detection means 91 detects the frequency characteristic of the high frequency signal as a predetermined signal propagated through the pipes 5 and 6.
Further, the signal detection unit 91 uses the frequency characteristics information of the predetermined signal detected at the first time or at a predetermined timing as the frequency at which the material provided on the outer periphery of the pipes 5 and 6 and the heat insulating materials 501 and 601 is in a normal state. The information is stored in the storage unit 93 as characteristic information.

The storage unit 93 stores information on frequency characteristics when the pipes 5 and 6 and the heat insulating materials 501 and 601 are in a normal state.
The storage unit 93 can be configured by a storage device such as a RAM (Random Access Memory) or a flash memory.

  The abnormality detection unit 92 compares the frequency characteristic stored in the storage unit 93 with the frequency characteristic of the predetermined signal detected by the signal detection unit 91, and detects abnormality in at least one of the pipes 5 and 6 and the heat insulating materials 501 and 601. The presence or absence of is detected. Details of the operation will be described later.

  The monitoring unit 94 acquires information regarding the presence or absence of an abnormality detected by the abnormality detection unit 92.

The abnormality detection unit 92 and the monitoring unit 94 can be realized by hardware such as a circuit device that realizes these functions, or can be realized as software executed on an arithmetic device such as a microcomputer or CPU.
Note that an interface necessary for outputting information related to the presence or absence of abnormality may be provided as appropriate.

In the above, the structure of the air conditioner and the piping diagnostic apparatus in this Embodiment was demonstrated.
Next, the operation of the piping diagnostic device in the present embodiment will be described.

<Operation>
First, the piping diagnostic device acquires frequency characteristics in a state where materials provided on the outer periphery of the piping such as the pipings 5 and 6 and the heat insulating materials 501 and 601 are not deteriorated or damaged (hereinafter also referred to as “normal state”). .

The acquisition of the frequency characteristic in the normal state is performed at the initial operation of the pipe diagnostic apparatus or at a predetermined timing.
Here, as the predetermined timing for acquiring the frequency characteristic information in the normal state, for example, when the pipe diagnostic device is operated for the first time after replacement and repair of the pipes 5 and 6, or when the connection configuration of the branch pipe is changed. Etc. are assumed.

The signal applying unit 71 of the diagnostic device 7 generates a high-frequency signal in a high-frequency band having a band of 1 MHz to 10 MHz, for example, and applies the high-frequency signal to the pipe 5 and the pipe 6 via the connection unit 8.
A signal in the high frequency band propagates between the pipe 5 and the pipe 6 using the metal part surface layer as a conductor.
The signal detection means 91 of the diagnostic device 9 detects the high-frequency signal that has propagated through the pipes 5 and 6 via the connection unit 10.
The signal detection means 91 measures the signal level (amplitude) for each detected high frequency signal.
For example, the signal detection unit 91 measures the gain-frequency characteristic between the outdoor unit 1 and the indoor unit c4 by calculating a difference from a known transmission signal level for each frequency.
And the signal detection means 91 memorize | stores the measured frequency characteristic in the memory | storage part 93 as information of the frequency characteristic in a normal state.

FIG. 3 is a diagram showing gain-frequency characteristics in a normal state according to the first embodiment.
In FIG. 3, the gain-frequency characteristic of the refrigerant pipe between the outdoor unit 1 and the indoor unit c4 is calculated and plotted in a frequency range of 1 MHz to 10 MHz.
Here, as shown in FIG. 1, the branch pipe 51 and the branch pipe 61 to the indoor unit a2 are electrically short-circuited by the refrigerant circuit inside the indoor unit a2. Further, the branch pipe 52 and the branch pipe 62 to the indoor unit b3 are electrically short-circuited by the refrigerant circuit inside the indoor unit b3.
The branch pipes 51 and 61 and the branch pipes 22 and 62 are each 20 m.
Therefore, as shown in FIG. 3, the frequency at which the gain is greatly reduced like a notch filter in the vicinity of the frequency where the length ¼ and ½ of the wavelength λ of the high frequency signal becomes the branch pipe length (20 m). It becomes a characteristic. Hereinafter, the frequency at which the gain greatly decreases is referred to as “attenuation frequency”.

  Since the frequency characteristics of the high-frequency signal propagated through the pipes 5 and 6 are determined by the propagation characteristics of the pipe surface layer, they do not depend on the temperature and state (liquid, gas, etc.) of the refrigerant flowing inside the pipe.

  Next, the relationship between the frequency characteristics of the high-frequency signal and the deterioration of the material provided on the pipe and the pipe outer periphery will be described.

FIG. 4 is a diagram illustrating the dielectric constant of the pipe in a normal state according to the first embodiment.
As shown in FIG. 4, when the pipes 5 and 6 and the heat insulating materials 501 and 601 are not deteriorated or damaged, the relative dielectric constant ε of the heat insulating materials 501 and 601 is a predetermined value (for example, ε≈1). have.

FIG. 5 is a diagram showing the dielectric constant of the pipe in the deteriorated state according to the first embodiment.
As shown in FIG. 5, for example, consider a case in which a part of the heat insulating materials 501 and 601 deteriorates and the pipes 5 and 6 located in the deteriorated portions 502 and 602 are directly exposed to the outside air.
When the refrigerant circulates in the pipes 5 and 6 by the operation of the air conditioner, water vapor contained in the air around the pipes 5 and 6 exposed to the outside air is condensed, and a part of the pipes 5 and 6 is condensed. As a result, the deteriorated portions 502 and 602 contain moisture.
At this time, since the relative permittivity of water is about 30, as shown in FIG. 5, the relative permittivity ε of the deteriorated portions 502 and 602 containing moisture increases compared to the normal time (for example, ε ≦ 30), the frequency characteristics of the pipes 5 and 6 as a whole change.

  Such moisture of the heat insulating materials 501 and 601 promotes oxidation of the metal surfaces of the pipes 5 and 6 and causes corrosion. And if corrosion progresses, a pinhole etc. will be made and the accident of refrigerant | coolant leakage will be induced.

  Here, the case where the dielectric constant is changed due to the condensation of the pipe has been described. However, the present invention is not limited to this, and the pipe 5 is similarly applied even if the heat insulating materials 501 and 601 are damaged, the work is poor, or the material changes due to aging. , 6 may change.

FIG. 6 is a diagram showing a gain-frequency characteristic in a deteriorated state according to the first embodiment.
In FIG. 6, gain-frequency characteristics are calculated when the length of 1 m of the branch pipes 52 and 62 to the indoor unit b3 contains moisture (condensation state in FIG. 5).
As shown in FIG. 6, the notch-shaped attenuation frequencies around 4 MHz and 9 MHz are shifted to around 3.5 MHz and 7 MHz, respectively.
This is because some of the heat insulating materials of the pipes 5 and 6 contain moisture, so that the dielectric constant becomes high, and the propagation speed in the section becomes slow due to the influence of the dielectric constant shown in the equation (1).

As described above, it is possible to detect that there is a high possibility that the heat insulating materials 501 and 601 are deteriorated or damaged, and the pipes 5 and 6 are corroded by the frequency characteristics of the high-frequency signal propagated through the pipes 5 and 6. It is.
Hereinafter, a state in which the materials provided on the outer circumferences of the pipes 5 and 6 and the heat insulating materials 501 and 601 are likely to be condensed, deteriorated, damaged, or corroded is referred to as “abnormal”.

  Next, an operation for detecting whether or not the pipes 5 and 6 and the heat insulating materials 501 and 601 are abnormal will be described.

The diagnostic devices 7 and 9 repeat the following measurement at predetermined intervals such as every hour, for example.
Note that this measurement may be performed at an arbitrary timing, for example, by an operation from the user.

First, the signal applying unit 71 of the diagnostic device 7 generates a high-frequency signal in a high-frequency band having a band of 1 MHz to 10 MHz, for example, and applies the high-frequency signal to the pipe 5 and the pipe 6 via the connection unit 8.
A signal in the high frequency band propagates between the pipe 5 and the pipe 6 using the metal part surface layer as a conductor.
The signal detection means 91 of the diagnostic device 9 detects the high-frequency signal that has propagated through the pipes 5 and 6 via the connection unit 10.
The signal detection means 91 measures the signal level (amplitude) for each detected high frequency signal.
For example, the signal detection unit 91 measures the gain-frequency characteristic between the outdoor unit 1 and the indoor unit c4 by calculating a difference from a known transmission signal level for each frequency.

The abnormality detection unit 92 compares the frequency characteristic of the high-frequency signal detected by the signal detection unit 91 with the frequency characteristic in the normal state stored in the storage unit 93 to detect the presence or absence of abnormality.
For example, the abnormality is detected as abnormal when the attenuation frequency of the high-frequency signal detected by the signal detection unit 91 changes by a predetermined value or more as compared with the attenuation frequency in the normal state.
In the example of FIG. 6, when the attenuation frequency around 4 MHz and around 9 MHz has changed by a predetermined value or more compared to the attenuation frequency in the normal state, the branch pipe 52 to the indoor unit b3 is measured. 62 and any one of the heat insulating materials 501 and 601 are detected to have abnormality such as condensation due to deterioration of the heat insulating material.

<Effect>
As described above, in the present embodiment, a predetermined signal is applied to the conductive pipes 5 and 6, and the presence or absence of an abnormality is detected based on the predetermined signal propagated through the pipes 5 and 6.
For this reason, it is possible to detect abnormalities in the materials such as the pipes 5 and 6 and the heat insulating materials 501 and 601 provided on the outer periphery of the pipes regardless of the presence of contents such as the refrigerant in the pipes 5 and 6.

  In addition, since abnormality can be detected regardless of the presence or absence of the contents in the pipes 5 and 6, the air conditioner is not subject to special diagnostic modes or operation restrictions, and in the normal operation state, condensation of pipes, etc. Thus, it is possible to prevent a refrigerant leakage accident.

  In addition, by preventing a refrigerant leakage accident, it is possible to prevent a decrease in energy consumption efficiency due to deterioration in air conditioning capability due to refrigerant leakage, and to prevent environmental pollution due to refrigerant leakage.

  Further, the user can prevent a refrigerant leakage accident by repairing an abnormal portion such as dew condensation based on the detection result.

  In the present embodiment, the case where the frequency characteristic in the normal state is measured at the first time or at a predetermined timing has been described. The present invention is not limited to this, and information on the attenuation frequency obtained from the pipe length of the pipes 5 and 6 and the configuration of the branch pipes is stored in the storage unit 93 in advance, and this information is compared with the frequency characteristics of the measured high-frequency signal. Then, the presence or absence of abnormality may be detected.

  If the physical structure of the pipe, such as the branch length to each indoor unit (the length of the branch pipe), is known, the frequency at which the notch appears (attenuation frequency) can be specified, so the length of the branch pipe and the notch frequency Can be associated. By comparing this association information with the frequency at which the notch has moved, it is possible to roughly identify which branch pipe is dewed.

For example, when the abnormality detection unit 92 detects that the attenuation frequency of the high-frequency signal detected by the signal detection unit 91 has changed by a predetermined value or more compared to the attenuation frequency in a normal state, Based on this, it is identified which of the main pipes 50 and 60, the branch pipes 51 and 61, and the branch pipes 52 and 62 is abnormal.
Since the attenuation frequency is determined by the length of the branch pipe, when there are a plurality of branch pipes having the same length, it is not possible to identify which branch pipe is abnormal. Even in this case, it is possible to narrow down the piping in which an abnormality has occurred among a large number of branch piping to the branch piping of the length. Thereby, for example, pipe candidates for maintenance such as deterioration inspection can be narrowed down to branch pipes of the length, and the number of maintenance steps can be reduced.

In the first embodiment, the frequency characteristics of the measured high-frequency signal are compared with the frequency characteristics in the normal state stored in the storage unit 93, but the present invention is not limited to this.
For example, the signal detection unit 91 stores information on the frequency characteristics of the measured high-frequency signal in the storage unit 93, and the abnormality detection unit 92 stores the stored frequency characteristics in the normal state and the stored frequency characteristics at the time of measurement. May be detected to detect the presence or absence of abnormality.

  In the first embodiment, the initial value and one measurement value are compared to determine condensation. However, the measurement value is accumulated as progress information of a predetermined period, and condensation occurs due to a change in notch frequency. A similar effect can be obtained by determining the possibility of corrosion.

For example, the abnormality detection unit 92 compares the frequency characteristics in the normal state stored in the storage unit 93 with the frequency characteristics of a plurality of high-frequency signals detected by the signal detection unit 91 at an arbitrary timing, and the comparison result Is stored in the storage unit 93, and the presence or absence of abnormality is detected based on the change over time of the comparison result stored in the storage unit 93.
Further, for example, the signal detection unit 91 detects a plurality of frequency characteristics of the high-frequency signal propagated through the pipes 5 and 6 at an arbitrary timing, and stores information on the plurality of frequency characteristics in the storage unit 93. Then, the abnormality detection unit 92 compares the frequency characteristics in the normal state stored in the storage unit 93 with the measured frequency characteristics stored in the storage unit 93, and stores information on the comparison results. The presence / absence of abnormality is detected based on the temporal change of the comparison result stored in the storage unit 93 and stored in the storage unit 93.

  In the first embodiment, a high-frequency signal having a band of 1 to 10 MHz is used as the predetermined signal applied from the diagnostic device 7, but the present invention is not limited to this. For example, in order to enable detection with a shorter branch pipe length, the frequency range of the high-frequency signal may be up to a frequency at which the wavelength of the high-frequency signal corresponds to 1/4 of the shortest branch length.

The diagnosis device 7 and the diagnosis device 9 may use a predetermined frequency band such as discrete multitone technology or direct frequency spectrum spreading technology used in OFDM (Orthogonal Frequency Division Multiplexing), ADSL (Asymmetric Digital Subscriber Line), and the like. The communication device used may be used.
For example, the gain characteristic may be acquired using a transmission path characteristic measurement mode such as communication availability of the communication device, information may be transmitted to another controller, and the controller may make a determination.
In this case, the communication device can also serve as the diagnostic devices 7 and 9 for detecting abnormalities such as dew condensation in the pipe, and detects condensation or the like that is a factor of refrigerant leakage without providing the diagnostic devices 7 and 9 separately. be able to.

  For example, when the diagnostic device 7 and the diagnostic device 9 are communication devices, the signal applying unit 71 modulates transmission information using a carrier frequency having a frequency band between 2 to 30 MHz, and a transmission signal having this frequency band. Is applied to the pipes 5 and 6 as a predetermined signal. Then, in addition to the above operation, the signal detection unit 91 may demodulate the transmission signal from the signal application unit 71 to acquire transmission information.

  In addition, although the diagnosis device 7 or the diagnosis device 9 has determined whether there is an abnormality such as condensation, the frequency characteristic information to be measured is transmitted to a remote controller or the like so that the controller can determine whether there is an abnormality. May be. In addition, information such as the detection result and the measured frequency characteristics can be displayed for the administrator, and the maintenance operator can be expected to assist such as specifying the place for maintenance.

  Further, for example, the monitoring means 94 is provided separately remotely, and the information regarding the presence or absence of abnormality detected by the abnormality detection means 92 is modulated into transmission signals as transmission information by the diagnosis device 7 and the diagnosis device 9 as communication devices, and the piping 5 and 6, and the monitoring means 94 may demodulate the transmission signal propagated through the pipes 5 and 6 to obtain information on the presence or absence of the abnormality detected by the abnormality detection means 92.

  In the first embodiment, the case where there are branch pipes to the indoor units a2 and b3 has been described. However, the present invention is not limited to this, and only the outdoor unit 1 and one indoor unit c4 are provided. The structure which does not provide may be sufficient. Even with such a configuration, it is possible to detect the presence or absence of an abnormality in the same manner as the above operation by attaching the diagnostic device 9 in the vicinity of the diagnostic device 7. In this case, the impedance upper 11 attached to the connection portion 10 is not necessary.

Embodiment 2. FIG.
<Configuration>
FIG. 7 is a diagram illustrating the configuration of the air conditioner and the pipe diagnosis device according to the second embodiment.
In FIG. 7, the configuration of the air conditioner is the same as that of the first embodiment, and the same parts are denoted by the same reference numerals.
In addition, as shown in FIG. 7, the piping diagnostic device in the present embodiment includes a diagnostic device 12.
The diagnosis device 12 is connected to one end of the pipes 5 and 6 separated in an alternating manner by the impedance upper 81 as in the first embodiment. The diagnostic device 12 is preferably connected to the pipes 5 and 6 in the vicinity of the outdoor unit 1 of the connection portion 8.
The configuration of the impedance upper 81 is the same as that of the first embodiment.

FIG. 8 is a diagram illustrating the configuration of the diagnostic apparatus according to the second embodiment.
As shown in FIG. 8, the diagnostic device 12 includes a signal applying unit 121, a signal detecting unit 122, and an abnormality detecting unit 123.

The signal applying unit 121 applies a pulse signal to the pipe as a predetermined signal.
The signal detector 122 detects the reflected wave of the pulse signal.
The abnormality detection means 123 detects the presence or absence of abnormality in at least one of the pipe and the material provided on the outer periphery of the pipe based on the delay time of the reflected wave.

In the above, the structure of the air conditioner and the piping diagnostic apparatus in this Embodiment was demonstrated.
Next, the operation of the piping diagnostic device in this embodiment will be described.

<Operation>
The principle of detection of anomalies using reflected waves and the operation of the diagnostic device 12 will be described with reference to FIGS. 8 to 12, taking as an example the configuration of one outdoor unit 1 and one indoor unit 4. .

FIG. 9 is a diagram schematically showing the impedance of the pipe in a normal state according to the second embodiment.
FIG. 10 is a diagram illustrating an impedance model in a normal state according to the second embodiment.
FIG. 11 is a diagram schematically showing the impedance of the pipe in the deteriorated state according to the second embodiment.
FIG. 12 is a diagram illustrating an impedance model in a deteriorated state according to the second embodiment.
FIG. 13 is a diagram showing a pulse waveform according to the second embodiment and transmission point waveforms at the normal time and at the time of deterioration.

  Here, a description will be given of a case where, for example, a stepped pulse signal as shown in the upper part of FIG. 13 is generated from the signal applying means 121 of the diagnostic device 12 and the signal is applied to the pipes 5 and 6 via the connecting portion 8. To do.

  The characteristic impedance Zo of the pipes 5 and 6 is determined by the following expressions (2), (3), and (4).

  As shown in FIG. 9, the characteristic impedance of the pipes 5 and 6 in the normal state (the state without condensation) is set to Z1. In this case, the end where the pipes 5 and 6 are connected to the indoor unit 4 (hereinafter referred to as “end B”) is electrically short-circuited by the refrigerant circuit inside the indoor unit 4. The impedance model at this time is shown in FIG.

For this reason, the stepped pulse signal applied to the end (hereinafter also referred to as “transmission end A”) to which the diagnostic device 12 is connected is reflected at the end B as shown in FIG.
Therefore, as shown in the transmission point waveform (1) of FIG. 13, at the transmission end A, the reflected wave reflected at the end B is superimposed on the applied pulse signal.
The time t1 from the application of the pulse signal until the reflected wave is superimposed is proportional to the position where the reflection occurs, that is, the distance from the transmitting end A to the end B shown in FIG. That is, a reflected wave delayed by time t1 is synthesized with the pulse signal.

  Next, for example, a case where a part of the heat insulating materials 501 and 601 deteriorates, a part of the pipes 5 and 6 condenses, and the deteriorated portions 502 and 602 of the heat insulating materials 501 and 601 contain moisture is considered.

In this case, the relative dielectric constant ε of the deteriorated portions 502 and 602 increases as compared with the normal time. Therefore, as shown in Expression (3), the capacitance C between the pipes increases. As a result, the characteristic impedance of the deteriorated parts 502 and 602 changes according to the equation (2). The characteristic impedance after this change is assumed to be Z2.
Therefore, as shown in FIG. 11, when a part of the pipes 5 and 6 is condensed, impedance mismatch occurs in the part. The impedance model at this time is shown in FIG.

  Thus, when a discontinuous portion of the impedance occurs in the signal transmission path, the peak value is reflected in the discontinuous portion based on the coefficient determined by the equation (5).

For this reason, the step-like pulse signal applied to the transmitting end A to which the diagnostic device 12 is connected is reflected by the deteriorated portions 502 and 602 where condensation occurs and the end B as shown in FIG. .
Therefore, as shown in the transmission point waveform (2) of FIG. 13, after the reflected waves reflected by the deteriorated portions 502 and 602 are superimposed at the transmitting end, the reflected waves reflected by the end B are superimposed.

  The time t2 until the reflected waves reflected by the degradation units 502 and 602 are superimposed is proportional to the position where the reflection occurs, that is, the distance from the transmission end A to the degradation units 502 and 602 shown in FIG. That is, after the reflected wave delayed by the time t2 is synthesized with the pulse signal, the reflected wave delayed by the time t1 is synthesized, and the stepped waveform is measured at the transmitting end A.

  Since such propagation time characteristics are determined by the propagation characteristics of the pipe surface layer, they do not depend on the temperature and state (liquid, gaseous state, etc.) of the refrigerant flowing inside the pipe.

  From the above, the abnormality detecting means 123 compares the transmission point waveform (1) with the transmission point waveform (2), and in the case where a plurality of reflected waves are superimposed on the pulse signal, the heat insulating material. It is possible to detect that deterioration or breakage of 501 and 601 and corrosion of the pipes 5 and 6 are highly likely.

  Further, the abnormality detection means 123 calculates the distance L corresponding to the time t2 from the equation (7) from the propagation velocity Vp shown in the equation (6), from the transmission end A, so that an abnormal location (a position where condensation occurs). ).

<Effect>
As described above, in the present embodiment, a pulse signal is applied to the pipes 5 and 6 and the presence or absence of abnormality is detected based on the delay time of the reflected wave of the pulse signal. Accordingly, as in the first embodiment, the abnormality of the materials such as the pipes 5 and 6 and the heat insulating materials 501 and 601 provided on the outer periphery of the pipes regardless of the presence of contents such as the refrigerant in the pipes 5 and 6. Can be detected.
Further, the distance between the transmission end and the abnormal part can be obtained from the delay time of the reflected wave.

  In the second embodiment, a simple one-to-one structure has been described for the purpose of explaining the principle. However, the present invention is not limited to this, and there may be a plurality of branch pipes as shown in FIG. In this case, the waveform stage (superimposed reflected wave) of the initial reflected wave is determined by the length and number of branch pipes, and is stored as an initial value, and a new comparison is made by sequentially comparing with the measured value. It becomes possible to detect the impedance discontinuity point, and it is possible to detect the dew spot that is the cause of the corrosion of the pipe.

  In addition, although the said Embodiment 1 and 2 demonstrated the case where the presence or absence of abnormality of the piping 5 and 6 and the heat insulating materials 501 and 601 was detected in the air conditioner, this invention is not limited to this. If the present invention is a pipe having conductivity, it is possible to detect the presence or absence of abnormality of the pipe and the material provided on the outer periphery thereof.

  As an application example of the piping diagnosis device according to the present invention, a piping monitoring device for an air conditioning system for buildings, etc., a home air conditioner, and other metal piping, such as a heat pump water heater, a floor heater, etc., are used for a piping maintenance system. Is raised.

  1 outdoor unit, 2 indoor unit a, 3 indoor unit b, 4 indoor unit c, 5 piping, 6 piping, 7 diagnostic device, 8 connection unit, 9 diagnostic device, 10 connection unit, 11 impedance upper, 12 diagnostic device, 22 Branch piping, 50 main piping, 51 branch piping, 52 branch piping, 60 main piping, 61 branch piping, 62 branch piping, 71 signal applying means, 81 impedance upper, 91 signal detecting means, 92 abnormality detecting means, 93 storage unit, 94 monitoring means, 121 signal applying means, 122 signal detecting means, 123 abnormality detecting means, 501 heat insulating material, 502 deteriorated portion, 601 heat insulating material, 602 deteriorated portion.

Claims (20)

A signal applying means for applying a predetermined signal to the conductive pipe;
Signal detection means for detecting the predetermined signal propagated through the pipe;
A pipe diagnostic apparatus comprising: an abnormality detection means for detecting whether or not there is an abnormality in at least one of the pipe and the material provided on the outer periphery of the pipe based on the predetermined signal detected by the signal detection means. Comprising first storage means for storing frequency characteristic information in a normal state of the pipe and the material provided on the outer periphery of the pipe;
The signal detection means includes
Detect frequency characteristics of the predetermined signal propagated through the pipe,
The abnormality detection means is
The frequency characteristic stored in the first storage means and the frequency characteristic of the predetermined signal detected by the signal detection means are compared, and an abnormality of at least one of the pipe and the material provided on the outer periphery of the pipe is detected. The piping diagnostic device according to claim 1, wherein presence or absence is detected. First storage means for storing frequency characteristic information in a normal state of the pipe and the material provided on the outer periphery of the pipe;
Second storage means,
The signal detection means includes
Detecting the frequency characteristic of the predetermined signal propagated through the pipe, and storing the frequency characteristic information in the second storage means;
The abnormality detection means is
Comparing the frequency characteristics stored in the first storage means with the frequency characteristics stored in the second storage means, whether or not there is an abnormality in at least one of the pipe and the material provided on the outer periphery of the pipe The piping diagnostic device according to claim 1, wherein First storage means for storing frequency characteristic information in a normal state of the pipe and the material provided on the outer periphery of the pipe;
A third storage means,
The signal detection means includes
Detect frequency characteristics of the predetermined signal propagated through the pipe,
The abnormality detection means is
The frequency characteristics stored in the first storage means and the frequency characteristics of the plurality of predetermined signals detected by the signal detection means at an arbitrary timing are respectively compared, and the information on the comparison results is compared with the third characteristics. Stored in the storage means
The presence or absence of an abnormality in at least one of the pipe and the material provided on the outer periphery of the pipe is detected based on a change with time of the comparison result stored in the third storage unit. Piping diagnostic equipment. First storage means for storing frequency characteristic information in a normal state of the pipe and the material provided on the outer periphery of the pipe;
A second storage means;
A third storage means,
The signal detection means includes
A plurality of frequency characteristics of the predetermined signal propagated through the pipe are detected at an arbitrary timing, and information on the plurality of frequency characteristics is stored in the second storage means,
The abnormality detection means is
The frequency characteristics stored in the first storage means and the plurality of frequency characteristics stored in the second storage means are respectively compared, and information of the comparison result is stored in the third storage means, respectively. ,
The presence or absence of an abnormality in at least one of the pipe and the material provided on the outer periphery of the pipe is detected based on a change with time of the comparison result stored in the third storage unit. Piping diagnostic equipment. The signal detection means includes
Information on the frequency characteristics of the predetermined signal detected at the first time or at a predetermined timing is stored in the first storage means as information on frequency characteristics of the pipe and the material provided on the outer periphery of the pipe in a normal state. The piping diagnosis device according to any one of claims 2 to 5. The abnormality detection means is
When the attenuation frequency of the predetermined signal detected by the signal detection means changes by a predetermined value or more compared to the attenuation frequency in a normal state, at least one of the pipe and the material provided on the outer periphery of the pipe is abnormal. The piping diagnostic device according to claim 2, wherein the piping diagnostic device is detected. The signal applying means includes
As the predetermined signal, a high frequency signal having a predetermined amplitude and a predetermined frequency band is applied to the pipe,
The signal detection means includes
The piping diagnostic apparatus according to claim 2, wherein a frequency characteristic of the high-frequency signal is detected. The signal applying means includes
As the predetermined signal, a high frequency signal having a predetermined amplitude is swept in a predetermined frequency range and applied to the pipe,
The signal detection means includes
The piping diagnostic apparatus according to claim 2, wherein a frequency characteristic of the high-frequency signal is detected. The signal applying means includes
As the predetermined signal, transmission information is modulated into a transmission signal having a predetermined frequency band and applied to the pipe,
The signal detection means includes
The piping diagnostic device according to claim 2, wherein the transmission information is acquired by demodulating the transmission signal. The signal applying means includes
The piping diagnosis apparatus according to claim 10, wherein the transmission information is modulated using a carrier frequency having a frequency band of 2 to 30 MHz. The signal applying means includes
The pipe diagnostic apparatus according to claim 10 or 11, wherein information relating to the presence or absence of an abnormality detected by the abnormality detection means is modulated into the transmission signal and applied to the pipe. 13. The pipe diagnosis apparatus according to claim 12, further comprising a monitoring unit that demodulates the transmission signal that has propagated through the pipe and acquires information about the presence or absence of an abnormality detected by the abnormality detection unit. The signal applying means includes
As the predetermined signal, a pulse signal is applied to the pipe,
The signal detection means includes
Detecting a reflected wave of the pulse signal;
The abnormality detection means is
The pipe diagnostic apparatus according to any one of claims 1 to 13, wherein presence or absence of abnormality of at least one of the pipe and a material provided on an outer periphery of the pipe is detected based on a delay time of the reflected wave. The abnormality detection means is
The distance between at least one abnormal portion of the pipe and the material provided on the outer periphery of the pipe and the application location of the predetermined signal is obtained based on the delay time of the reflected wave. Pipe diagnostic device. The piping is
Main piping,
Having one or more branch pipes branched from the main pipe,
The abnormality detection means is
When detecting an abnormality of at least one of the pipe and the material provided on the outer periphery of the pipe,
16. The pipe diagnostic apparatus according to claim 1, wherein which of the main pipe and the one or a plurality of branch pipes is abnormal is identified. The abnormality detection means is
When the attenuation frequency of the predetermined signal detected by the signal detection means changes by a predetermined value or more compared to the attenuation frequency in a normal state, at least one of the pipe and the material provided on the outer periphery of the pipe is abnormal. Detects that there is,
The pipe diagnostic device according to claim 16, wherein which of the main pipe and the branch pipe is abnormal is identified based on the attenuation frequency. Indoor unit,
Outdoor unit,
A heat insulating material is provided on the outer periphery of the conductive pipe, and a pipe for circulating a refrigerant in the indoor unit and the outdoor unit;
An air conditioner comprising the piping diagnostic device according to any one of claims 1 to 17. A plurality of the indoor units are provided,
The piping is
Among the plurality of indoor units, main piping that connects any indoor unit and the outdoor unit,
Branching from the main pipe and having one or a plurality of branch pipes connecting the other indoor units and the outdoor unit,
The piping diagnostic device is
When detecting an abnormality of at least one of the pipe and the heat insulating material,
The air conditioner according to claim 18, wherein which of the main pipe and the one or more branch pipes is abnormal is identified. An impedance adjuster for alternatingly separating the pipe from at least one of the indoor unit and the outdoor unit;
The air conditioner according to claim 18 or 19, wherein the signal applying means applies the predetermined signal to one end of the pipe separated in an AC manner.

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