JP7654338B2 - Refrigerant Leak Detection System - Google Patents

Description

This disclosure relates to a refrigerant leak detection system for detecting whether a refrigerant leak has occurred from a refrigerator.

For example, in the refrigerant leak detection system described in Patent Document 1, refrigerant detection sensors are placed in multiple locations to detect refrigerant leaking from a refrigerator.

International Publication No. WO2019/038797

The refrigerant leak detection system described in Patent Document 1 requires the same number of refrigerant detection sensors as the locations to be detected (hereinafter referred to as monitoring locations). In view of this point, the present disclosure discloses an example of a refrigerant leak detection system that can monitor multiple monitoring locations with a smaller number of refrigerant detection sensors than the number of monitoring locations.

It is desirable for a refrigerant leak detection system for detecting whether a refrigerant leak has occurred from the refrigerator (1) to have at least one of the following components:

That is, the components are a refrigerant detection sensor (11) that detects the refrigerant contained in the air, a first sampling pipe (12) that guides the atmosphere of a specific location of the refrigerator (1) to the refrigerant detection sensor (11), a second sampling pipe (13) that guides the atmosphere of a location of the refrigerator (1) other than the specific location to the refrigerant detection sensor (11), a switching device (14) that switches between guiding the atmosphere to the refrigerant detection sensor (11) through the first sampling pipe (12) and guiding the atmosphere to the refrigerant detection sensor (11) through the second sampling pipe (13), and an alarm unit (15A) that issues an alarm when the refrigerant is detected by the refrigerant detection sensor (11).

By switching between directing the atmosphere to the refrigerant detection sensor (11) through the first sampling pipe (12) and directing the atmosphere to the refrigerant detection sensor (11) through the second sampling pipe (13), it becomes possible to monitor multiple monitoring points with a smaller number of refrigerant detection sensors (11) than the number of monitoring points.

Incidentally, the symbols in parentheses above are examples showing the corresponding relationship with the specific configurations etc. described in the embodiments described below, and the present disclosure is not limited to the specific configurations etc. shown by the symbols in parentheses above.

1 is a diagram showing a refrigerant leakage detection system according to a first embodiment; 4 is an example of a flowchart showing the operation of the refrigerant leakage detection system according to the first embodiment.

The following "embodiment of the invention" shows an example of an embodiment that falls within the technical scope of this disclosure. In other words, the invention-specific matters described in the claims are not limited to the specific configurations and structures shown in the embodiment below.

At least one of each of the components or parts described with a reference number is provided, unless otherwise specified by "one". In other words, unless otherwise specified by "one", two or more of the components may be provided. The air conditioner shown in this disclosure includes at least the components or parts described with a reference number, as well as the structural parts shown in the drawings.

First Embodiment
<1. Overview of the refrigerant leak detection system (see Figure 1)>
In this embodiment, the refrigerant leakage detection system according to the present disclosure is applied to a refrigerant leakage detection system for detecting whether or not a refrigerant leak has occurred from a refrigerator 1 for an air conditioner.

The refrigerator 1 according to this embodiment is a vapor compression refrigerator having a compressor 2, a radiator 3, a pressure reducer 4, and an evaporator 5. The compressor 2 compresses the low-pressure gas-phase refrigerant that flows out of the evaporator 5. The radiator 3 cools the high-pressure refrigerant that is discharged from the compressor 2 and has an increased temperature.

The pressure reducer 4 reduces the pressure of the refrigerant flowing out from the radiator 3. The pressure reducer 4 in this embodiment is composed of a thermostatic expansion valve. The thermostatic expansion valve automatically adjusts the opening (pressure reduction) so that the degree of superheat of the refrigerant at the outlet side of the evaporator 5 becomes a predetermined value.

The evaporator 5 evaporates the liquid-phase refrigerant decompressed by the pressure reducer 4 to generate refrigeration capacity, i.e., cold heat. Specifically, the evaporator 5 exchanges heat between the air to be supplied to the space to be air-conditioned and the refrigerant, thereby cooling the air.

2. Refrigerant leak detection system
2.1 Configuration of refrigerant leak detection system (see Figure 1)
The refrigerant leak detection system 10 at least includes a refrigerant detection sensor 11, a first sampling pipe 12, a second sampling pipe 13, a switching device 14, and a refrigerant leak monitoring device 15. The refrigerant detection sensor 11 is a detector that detects refrigerant contained in the air.

The first sampling pipe 12 and the second sampling pipe 13 are atmosphere introduction pipes that introduce the atmosphere present at a specific location of the refrigerator 1 to the refrigerant detection sensor 11. The suction port of the first sampling pipe 12 and the suction port of the second sampling pipe 13 open at different locations.

In other words, the atmosphere guided to the refrigerant detection sensor 11 through the first sampling pipe 12 and the atmosphere guided to the refrigerant detection sensor 11 through the second sampling pipe 13 are atmospheres in different locations.

In this embodiment, the first sampling pipe 12, for example, guides the atmosphere around the radiator 3 to the refrigerant detection sensor 11. The second sampling pipe 13, for example, guides the atmosphere around the evaporator 5 to the refrigerant detection sensor 11.

The switching device 14 is a device for switching between directing the atmosphere to the refrigerant detection sensor 11 through the first sampling pipe 12 and directing the atmosphere to the refrigerant detection sensor 11 through the second sampling pipe 13.

The switching device 14 in this embodiment is composed of on-off valves 14A and 14B, the same number as the sampling pipes. On-off valve 14A (hereinafter referred to as first on-off valve 14A) controls the communication state between the first sampling pipe 12 and the refrigerant detection sensor 11.

The on-off valve 14B (hereinafter referred to as the second on-off valve 14B) controls the communication state between the second sampling pipe 13 and the refrigerant detection sensor 11. The fan 14C is an aspirator for sucking in the atmosphere.

The refrigerant leakage monitoring device 15 controls the operation of the switching device 14 and has an alarm unit 15A. That is, the output signal of the refrigerant detection sensor 11 is input to the refrigerant leakage monitoring device 15. The alarm unit 15A issues an alarm when the refrigerant is detected by the refrigerant detection sensor 11.

The refrigerant leakage monitoring device 15 is configured with a CPU, a ROM, and a microcomputer having a ROM, etc. The refrigerant leakage monitoring device 15 controls the switching device 14 and the alarm unit 15A by software being executed by the CPU. The software is pre-stored in a non-volatile storage unit such as a ROM.

<2.2 Control of switching devices, etc.>
<Control Overview>
The refrigerant leakage monitoring device 15 monitors for refrigerant leakage by opening both the first on-off valve 14A and the second on-off valve 14B. When the refrigerant detection sensor 11 detects a refrigerant leakage, the refrigerant leakage monitoring device 15 alternately closes either the first on-off valve 14A or the second on-off valve 14B.

In other words, the refrigerant leakage monitoring device 15 switches between directing the atmosphere to the refrigerant detection sensor 11 through the first sampling pipe 12 and directing the atmosphere to the refrigerant detection sensor 11 through the second sampling pipe 13 at predetermined time intervals. Hereinafter, this operation is referred to as switching control.

The refrigerant leakage monitoring device 15 then performs a leak location identification function to identify the sampling tube (hereinafter referred to as the leak detection tube) that is connected to the refrigerant detection sensor 11 when switching control is being performed and refrigerant is detected.

Next, the refrigerant leak monitoring device 15 closes the on-off valve installed in the identified leak detection tube to keep the leak detection tube in a disconnected state and issues a warning that a refrigerant leak has occurred around the suction port of the leak detection tube.

The above warning is sent to the person in charge of managing the refrigeration unit 1 (hereinafter referred to as the manager). Upon receiving the warning, the manager takes appropriate measures to deal with the refrigerant leak and then instructs the refrigerant leak monitoring device 15 that the measures have been completed.

<Control details (see Figure 2)>
2 is an example of a flowchart of the operation control. The operation control is started in conjunction with the start-up of the refrigerator 1. When the operation control is started, the refrigerant leakage monitoring device 15 first monitors for refrigerant leakage (S3) with the first on-off valve 14A and the second on-off valve 14B open (S1).

If a refrigerant leak is detected (S3: YES), the refrigerant leak monitoring device 15 closes the second opening/closing valve 14B for a predetermined time (S5) and determines whether a refrigerant leak has been detected (S7).

If a refrigerant leak is detected (S7: YES), the refrigerant leak monitoring device 15 issues a report indicating that a refrigerant leak has occurred and the location of the leak (S13), and closes the on-off valve installed in the leak detection tube to keep the leak detection tube in a disconnected state (S15).

If no refrigerant leakage is detected (S7: NO), the refrigerant leakage monitoring device 15 closes the first on-off valve 14A and then opens the second on-off valve 14B (S9) and determines whether or not a refrigerant leakage has been detected (S11).

If a refrigerant leak is detected (S11: YES), the refrigerant leak monitoring device 15 executes S13 and S15. If a refrigerant leak is not detected (S11: NO), the refrigerant leak monitoring device 15 executes S1 again.

When the on-off valve installed in the leak detection tube is closed (S15), the refrigerant leak monitoring device 15 continues to monitor for refrigerant leaks in the atmosphere introduced through a sampling tube other than the leak detection tube (S17).

<3. Features of the refrigerant leak detection system according to this embodiment>
In the refrigerant leak detection system 10 of this embodiment, by switching between directing the atmosphere to the refrigerant detection sensor 11 through the first sampling pipe 12 and directing the atmosphere to the refrigerant detection sensor 11 through the second sampling pipe 13, it is possible to monitor multiple monitoring locations using a smaller number of refrigerant detection sensors 11 than the number of monitoring locations.

In this embodiment of the refrigerant leak detection system 10, all sampling tubes are connected to the refrigerant detection sensor 11 to monitor for the presence or absence of refrigerant leaks, and switching control is performed when a refrigerant leak is detected in this state.

This makes it possible to detect refrigerant leaks more quickly than in a configuration that performs switching control without connecting all sampling tubes to the refrigerant detection sensor 11.

In other words, for example, when the first sampling pipe 12 is connected and the second sampling pipe 13 is not connected, even if a refrigerant leak occurs on the suction side of the second sampling pipe 13, the refrigerant leak monitoring device 15 cannot detect the refrigerant leak until the connection state is switched.

In contrast to this, in this embodiment, the presence or absence of refrigerant leakage is monitored with all sampling tubes connected to the refrigerant detection sensor 11, so no matter where a refrigerant leakage occurs, the refrigerant leakage monitoring device 15 can quickly detect the refrigerant leakage.

Other Embodiments
In the above embodiment, since there are two monitoring locations, two sampling tubes are provided. However, the present disclosure is not limited to this. That is, the present disclosure is also applicable to a configuration in which there are three or more monitoring locations, for example. The number of sampling tubes is the same as the number of monitoring locations.

The switching device 14 according to the above embodiment is configured with the same number of on-off valves as the number of sampling pipes. However, the present disclosure is not limited to this. That is, the present disclosure may also be configured such that the switching device 14 is configured with, for example, one or more switching valves.

In the above embodiment, the presence or absence of refrigerant leakage is monitored while all sampling tubes are connected to the refrigerant detection sensor 11, and when a refrigerant leakage is detected in this state, switching control is performed to execute the leak location identification function.

However, the present disclosure is not limited to this. That is, the present disclosure may, for example, execute switching control without connecting all sampling tubes to the refrigerant detection sensor 11. In other words, the presence or absence of a refrigerant leak and the leak detection tube may be identified by switching the connected sampling tube at predetermined time intervals.

In the above-described embodiment, the refrigerator is configured with one refrigerator. However, the present disclosure is not limited to this. That is, the disclosure may be configured, for example, such that the refrigerator described in the claims is configured with two refrigerators, and the atmosphere around the evaporator of the first refrigerator is introduced to the refrigerant detection sensor 11 by the first sampling pipe 12, and the atmosphere around the evaporator of the second refrigerator is introduced to the refrigerant detection sensor 11 by the second sampling pipe 13.

Furthermore, the present disclosure is not limited to the above-mentioned embodiments as long as it conforms to the spirit of the disclosure described in the above-mentioned embodiments. Therefore, the present disclosure may be a configuration in which at least two of the above-mentioned embodiments are combined, or a configuration in which any of the constituent elements illustrated or the constituent elements described with reference numerals in the above-mentioned embodiments are eliminated.

REFERENCE SIGNS LIST 1... Refrigerating machine 2... Compressor 3... Radiator 4... Pressure reducer 5... Evaporator 10... Refrigerant leakage detection system 11... Refrigerant detection sensor 12... First sampling pipe 13... Second sampling pipe 14... Switching device 15... Refrigerant leakage monitoring device 15A... Alarm section

Claims (3)

A refrigerant leak detection system for detecting whether a refrigerant leak has occurred from a refrigerator, comprising:
A refrigerant detection sensor that detects refrigerant contained in the air;
a first sampling pipe that introduces an atmosphere at a specific location of the refrigerator to the refrigerant detection sensor;
a second sampling pipe that introduces an atmosphere at a location different from the specific location of the refrigerator to the refrigerant detection sensor;
a switching device for switching between a case where the atmosphere is introduced to the refrigerant detection sensor through the first sampling pipe and a case where the atmosphere is introduced to the refrigerant detection sensor through the second sampling pipe, the switching device having at least a first on-off valve that controls a communication state between the first sampling pipe and the refrigerant detection sensor, and a second on-off valve that controls a communication state between the second sampling pipe and the refrigerant detection sensor;
a refrigerant leakage monitoring device capable of controlling the operation of the switching device, the refrigerant leakage monitoring device being capable of performing a leak location identification function of identifying a sampling tube (hereinafter referred to as a leak detection tube) that is in communication with the refrigerant detection sensor when a refrigerant is detected;
The refrigerant leakage monitoring device opens both the first and second on-off valves to monitor for refrigerant leakage, and when a refrigerant leakage is detected by the refrigerant detection sensor, alternately closes either the first or second on-off valve at predetermined time intervals, thereby identifying the leak detection tube . The refrigerant leakage detection system according to claim 1 , further comprising an alarm unit that issues an alarm when the refrigerant is detected by the refrigerant detection sensor . 3. The refrigerant leakage detection system according to claim 2, wherein the switching device maintains the leak detection tube in a non-communicating state when the refrigerant is detected .

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