JP3162132B2 - Refrigeration device control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a refrigerant circuit formed by connecting an indoor unit having a heat exchanger and an expansion valve and an outdoor unit having a compressor and a heat exchanger by gas pipes and liquid pipes. The present invention relates to a refrigeration apparatus that circulates a refrigerant in a refrigerant circuit to perform air conditioning, and more particularly to a refrigeration apparatus control method that minimizes leakage of a refrigerant even when the refrigerant leaks due to a failure of the refrigeration apparatus.

[0002]

2. Description of the Related Art Freon refrigerants, which are widely used in general air conditioning refrigeration systems, are considered to have extremely low toxicity. For this reason, at present, even in a direct expansion type refrigeration apparatus having a heat exchanger in the room, there are few examples of countermeasures in the case where the refrigerant leaks. Therefore, if a refrigerant leaks from the refrigeration apparatus, almost the entire amount of the refrigerant filled in the refrigeration apparatus is discharged indoors or into the atmosphere.

In recent years, the number of multi-type refrigerating apparatuses in which one outdoor unit drives a plurality of indoor units has increased, and the amount of refrigerant charged in a refrigerant circuit of the refrigerating apparatus has increased. When a refrigerant leaks from such a refrigerating device and a large amount of refrigerant is discharged indoors, a person in the indoor is exposed to a dangerous state such as oxygen deficiency.

Therefore, as disclosed in Japanese Utility Model Laid-Open Publication No. 61-74078, when a detecting device provided in a room detects the concentration of Freon gas above a predetermined level, when the oxygen concentration becomes lower than a predetermined level, An emergency refrigerant discharging device has been proposed in which, when the detection is also performed, the refrigerant discharging device provided in the outdoor unit is operated according to a command from the detecting device.

[0005]

Conventionally, as a refrigerant for a refrigeration system, a CFC refrigerant such as chlorodifluoromethane (hereinafter referred to as CFC22) is mainly used. However, the release of these CFCs into the atmosphere in recent years has caused so-called global warming, and some CFCs have a negative impact on the global environment, such as destruction of the stratospheric ozone layer. Has been pointed out.

Accordingly, an object of the present invention is to prevent a person in a room from being exposed to a dangerous state such as oxygen deficiency when a refrigerant leaks from a refrigeration apparatus, and to reduce the amount of chlorofluorocarbon gas which has a bad influence on the global environment to the atmosphere. It is intended to minimize the release to the public.

[0007]

Means for Solving the Problems In order to achieve the above object, the prior invention and the invention according to claims 1 to 6 (hereinafter referred to as the invention)
The method for controlling a refrigeration apparatus according to the present invention
An indoor unit having a heat exchanger and an expansion valve, and an outdoor unit having a compressor and a heat exchanger, are connected by a gas pipe and a liquid pipe to form a refrigerant circuit, circulate a refrigerant in the refrigerant circuit, and In a direct expansion / separation type refrigeration apparatus that directly contacts indoor air with a heat exchanger to balance indoor air, a gas pipe opening / closing valve and a liquid pipe opening / closing valve are provided in the middle of each of the pipes, and refrigerant from the refrigeration apparatus is removed. A leakage detection device for detecting leakage is provided indoors and / or outdoors, and the on-off valve is closed when the leakage detection device detects leakage of a predetermined amount or more of refrigerant.

Further, a leak detecting device is provided in a room where the indoor unit of the refrigeration device is installed, and when the leak detecting device detects leakage of the refrigerant of a predetermined amount or more, the liquid pipe opening / closing valve is closed, and a predetermined period of time or the operation of the compressor is stopped. The compressor is operated until the suction side pressure decreases to a predetermined value to collect the refrigerant in the outdoor unit, and then the gas pipe opening / closing valve is closed.

In addition, the refrigeration system can be switched between a cooling operation and a heating operation, and a leak detection device is provided in a room where the indoor unit of the refrigeration device is installed. When the cooling operation is performed, close the liquid piping on-off valve.
While switching to cooling operation, close the liquid piping on-off valve,
The compressor is operated for a predetermined time or until the suction-side pressure of the compressor drops to a predetermined value to collect the refrigerant in the outdoor unit, and then the gas pipe opening / closing valve is closed.

Further, a leak detecting device is provided in or near the outdoor unit of the refrigeration system, and when the leak detecting device detects the leakage of a predetermined amount or more of the refrigerant, the liquid piping on-off valve is closed when the refrigeration system is in the heating operation. When the refrigerating device is in the cooling operation, the operation is switched to the heating operation, the liquid pipe on / off valve is closed, and the refrigerant is operated by operating the compressor for a predetermined time or until the suction side pressure of the compressor drops to a predetermined value. After being collected in the indoor unit, the gas pipe opening / closing valve is closed.

Further, a plurality of indoor units having a heat exchanger and an expansion valve and one outdoor unit having a compressor and a heat exchanger are connected by a gas pipe and a liquid pipe to form a refrigerant circuit. In a multi-type refrigeration apparatus that circulates a refrigerant in a refrigerant circuit, a gas pipe open / close valve and a liquid pipe open / close valve are provided in the middle of each of the pipes, and a refrigerant leak detection device is provided in each room provided with an indoor unit, When the leak detection device detects a leak of a predetermined amount or more of the refrigerant, the on-off valve provided in the pipe connecting the indoor unit and the outdoor unit provided in the room where the leak is detected is closed.

Further, an indoor leak detecting device and an outdoor leak detecting device are provided which allow a refrigeration device to be freely switched between a cooling operation and a heating operation, and detect leakage of a refrigerant both indoors where an indoor unit is installed and inside or near an outdoor unit. Is established,
When the indoor leak detection device and / or the outdoor leak detection device detects the leakage of the refrigerant that is equal to or more than a predetermined value, the liquid piping on-off valve is closed when the refrigeration device is in the cooling operation, and the cooling operation is performed when the refrigeration device is in the heating operation. Switching, closing the liquid pipe on-off valve, operating the compressor for a predetermined time or until the suction side pressure of the compressor drops to a predetermined value, recovering the refrigerant to the outdoor unit, and then closing the gas pipe on-off valve It is.

Further, a ventilation device is installed in a room in which the indoor unit is installed, and the operation of the ventilation device is controlled by a signal of a refrigerant leak detection device provided in the room.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration of an embodiment of a direct expansion separation type refrigeration apparatus to which the present invention is applied.

In FIG. 1, an indoor unit 2 of a refrigeration system having an indoor exchanger 4 and an expansion valve 5 is installed in a room or room 1 and has an indoor unit 3 having a compressor 6 and an outdoor heat exchanger 7. Are connected by a liquid pipe 10a and a gas pipe 10b to form a refrigeration cycle. Liquid piping 10
a, a substantially liquefied refrigerant flows through the gas pipe 10
A substantially vaporized refrigerant flows through b. Liquid piping 10
a and the gas pipe 10b, a liquid pipe opening / closing valve 11a
And a gas pipe opening / closing valve 11b, for example, an electromagnetic valve is used for these opening / closing valves. In the room or the room 1, a leakage detection device 12 for detecting leakage of the refrigerant is provided, and the leakage detection device 12 includes, for example, a concentration of a Freon gas refrigerant having a predetermined value or more, an oxygen concentration having a predetermined value or less, and The leakage of the refrigerant is detected by detecting both of them. Power lines and signal lines of the on-off valves 11a and 11b, the leak detection device 12, and the like are connected to a power supply (not shown) and the control device 20, respectively. The arrows in the figure indicate the flow direction of the refrigerant charged in the refrigeration cycle.

The refrigerant gas, such as Freon 22, compressed by the compressor 6 is cooled and liquefied by the outdoor heat exchanger 7. The liquid refrigerant is decompressed by the expansion valve 5 of the indoor unit 2 through a pipe 10a having an opening / closing valve 11a on the way, exchanges heat with indoor air in the indoor heat exchanger 4, and performs a cooling operation. The vaporized refrigerant repeats the refrigeration cycle which is sucked into the compressor 6 again through the pipe 10b having the on-off valve 11b in the middle.

FIG. 2 shows an example of a control flow chart based on the control device 20 of the refrigeration system configured as shown in FIG. if,
When a failure occurs in the refrigerating device, the refrigerant charged in the refrigerating device leaks into the room 1 and the detecting device 12 detects the concentration of the CFC gas that is equal to or higher than a predetermined value, or when the oxygen concentration is equal to or lower than a predetermined value, or When both are detected together, the on-off valves 10a and 10b are closed and the compressor 6 is stopped. Therefore, only the refrigerant on the indoor unit 2 side from the on-off valves 10a and 10b leaks into the room 1, and the refrigerant on the outdoor unit 3 side does not leak into the room 1. Although the leak detection device 12 is provided only in the room 1 in FIG. 1, the leak detection device 12 is provided inside or outside the outdoor unit 3, or provided both inside and outside the room, that is, inside and / or outside the room. Provided,
On-off valve 1 based on leak detection by these leak detection devices
The closing operation of 0a and 10b and the stop of the compressor can be performed.

FIG. 3 shows another example of a control flow chart of the refrigeration system. If a failure occurs in the refrigeration apparatus and the refrigerant charged in the refrigeration apparatus leaks into the room 1, the detection device 12 detects the refrigerant leakage and closes the on-off valve 11a first. The compressor 6 continues to operate, and the suction pressure reaches a set value (for example, atmospheric pressure).
When it becomes lower, the on-off valve 10b is closed and the compressor 6 is stopped. Therefore, the refrigerant on the indoor unit 2 side is collected on the outdoor unit 3 side, so that the refrigerant can hardly leak into the room 1.

FIG. 4 shows an example in which the present invention is applied to a heat pump refrigeration apparatus. In the figure, components having the same reference numerals as those in FIG. 1 are the same parts, and the description thereof is omitted. The outdoor unit 3 includes a four-way valve 9 for switching between a cooling operation and a heating operation by changing the flow direction of the refrigerant, an expansion valve 8, and a detector 13 for detecting leakage of the refrigerant. The arrows in the figure indicate the flow direction of the refrigerant charged in the refrigeration cycle, where the solid line indicates the cooling operation and the broken line indicates the heating operation.

The flow of the refrigerant during the cooling operation will be described. Refrigerant gas compressed by the compressor 6, for example, Freon 22
Reaches the outdoor heat exchanger 7 through the four-way valve 9 and is cooled and liquefied. The liquid refrigerant is decompressed by the expansion valve 5 of the indoor unit 2 through a liquid pipe 10a having an on-off valve 11a on the way,
The indoor heat exchanger 4 exchanges heat with indoor air to evaporate and perform a cooling operation. The vaporized refrigerant passes through a gas pipe 10b having an on-off valve 11b in the middle and a four-way valve 9 to be sucked into the compressor 6 again to repeat a refrigeration cycle. In the heating operation, the refrigerant gas compressed by the compressor 6 reaches the indoor heat exchanger 4 through the four-way valve 9 and the piping 10b having the on-off valve 11b on the way, and exchanges heat with indoor air. It condenses and liquefies and performs a heating function. The liquefied refrigerant is depressurized by the expansion valve 8 of the outdoor unit 3 through the pipe 10a having the opening / closing valve 11a on the way, and exchanges heat with outdoor air in the outdoor heat exchanger 7 to be vaporized. The vaporized refrigerant passes through the four-way valve 9 and is again sucked into the compressor 6 to repeat the refrigeration cycle.

FIG. 5 shows an example of a control flow chart based on the control device 20 of the refrigeration system configured as described above. If a failure occurs on the indoor unit 2 side and the refrigerant charged in the refrigerating device leaks into the room 1, the indoor detecting device 12 detects the refrigerant leakage. At this time, when the refrigerating apparatus is in the cooling operation, the on-off valve 11a is closed, and in the heating operation, the four-way valve 8 switches to the cooling operation, and then the on-off valve 11a is closed. The compressor 7 continues to operate, and when the suction pressure becomes lower than a set value (for example, atmospheric pressure), the on-off valve 11b is closed to stop the compressor 6. Therefore, the refrigerant on the indoor unit 2 side is collected on the outdoor unit 3 side.
Can be almost eliminated.

If a failure occurs on the side of the outdoor unit 3 and the refrigerant filled in the refrigerating device leaks, the outdoor detecting device 13 detects the refrigerant leak. At this time, when the refrigeration system is in the heating operation, the on-off valve 11a is closed. In the cooling operation, the four-way valve 9 switches to the heating operation.
Close 1a. The compressor 7 continues to operate, and when the suction pressure becomes lower than the set value, the on-off valve 11b is closed to stop the compressor 6. Therefore, since the refrigerant on the outdoor unit 3 side is collected on the indoor unit 2 side, the refrigerant can hardly be released into the atmosphere.

FIG. 6 shows an example in which the present invention is applied to a direct expansion separation type three-chamber multi-refrigeration apparatus. In the figure, those having the same reference numerals as those in FIGS. 1 and 4 are the same parts, and the description thereof will be omitted. Indoor units 2a, 2b, and 2c
Are installed in the rooms 1a, 1b, and 1c in which the refrigerant leak detection devices 12a, 12b, and 12c are installed, respectively. On the way of the pipes 10a, 10b connecting the respective indoor units and the outdoor units 3, on-off valves 11a, 11b, 14a, 14b, 15a, 15
b is provided. The arrows in the figure are the flow directions of the refrigerant charged in the refrigeration cycle, as in FIG. 4, the solid line indicates the cooling operation, and the broken line indicates the heating operation. Also, the flow of the refrigerant is the same as that of FIG.
Since it is the same as that of FIG.

FIG. 7 shows an example of a control flow chart of the refrigeration apparatus thus configured.

When the detecting device 12a, 12b, or 12c detects the leakage of the refrigerant, when the refrigerating device is in the cooling operation, the liquid piping on / off valves 11a, 14a, and 15a are all closed once, and the refrigerating device is heated. In the case of operation, after switching to the cooling operation by the four-way valve 9, the incoming liquid pipe opening / closing valve 11
a, 14a, and 15a are all closed once, and the refrigerant in the indoor unit is recovered to the outdoor unit until the suction pressure becomes lower than a set value (for example, atmospheric pressure). When the suction pressure becomes lower than the set value, the return gas pipe opening / closing valve connected to the indoor unit installed in the room where the leakage of the refrigerant is detected is closed, and the opening / closing valves connected to other indoor units are opened. That is, at this point, the on-off valve leading to the leak-free indoor unit opens both the liquid pipe and the gas pipe, that is, both the going and the returning. For example, when a leak is detected by the detector 12a, the on-off valve 11b is closed and the on-off valves 14a and 1 are closed.
5a is opened. In this case, the on-off valves 14b, 15b
Is open from the beginning. If the refrigeration apparatus is returned to the normal operation after performing the above operation, the indoor unit in which the refrigerant does not leak can perform the cooling or heating operation.

FIG. 8 shows still another embodiment of the present invention.
In the present embodiment, a ventilation device 30 for the room 1 is added to the refrigerating device shown in FIG. 1, and the other components are the same as those in FIG. . The power supply and signal line of the ventilator 30 are connected to the power supply and the control device 20, and operate the ventilator 30 when the refrigerant leak detection device detects a predetermined or more refrigerant leak.
With this configuration, even if a failure occurs in the refrigeration system and the refrigerant leaks into the room 1, the refrigerant can be quickly discharged by the ventilation device 30. The control device 20 includes, in addition to the ventilator 30, the on-off valves 11a,
Of course, the control of 11b is performed. The ventilation device 30 can be added to the room 1 shown in FIGS.

In the above embodiment, the on-off valves 11a,
11b, 14a, 14b, 15a, and 15b are provided outside the indoor unit 2 and the outdoor unit 3. However, if the piping unit connects the indoor unit and the outdoor unit substantially, the indoor unit 2 or the outdoor unit 3 is provided. You may put it inside.

In the control flow charts shown in FIGS. 3, 5 and 7, the on / off valve 11a is closed or the
After closing a, 14a, and 15a, the refrigerant recovery operation is performed until the suction pressure becomes lower than the set value. However, a predetermined time (time taking into account the time until the suction pressure becomes lower than the set value) is considered. ) May be used for the recovery operation.

[0029]

The present invention is constructed as described above.
Provided is a safe refrigerating apparatus that can prevent a person in a room from being exposed to a dangerous state such as oxygen deficiency even if the refrigerant leaks into the room, and that minimizes refrigerant discharged into the atmosphere. be able to.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention and is a schematic configuration diagram of a direct expansion separation type refrigeration apparatus to which the present invention is applied.

FIG. 2 is an example of a control flowchart of the refrigeration apparatus shown in FIG.

FIG. 3 shows another example of a control flow chart of the refrigeration apparatus shown in FIG.

FIG. 4 shows another embodiment of the present invention, and is a schematic configuration diagram of a heat pump refrigeration apparatus to which the present invention is applied.

5 is an example of a control flowchart of the refrigeration apparatus shown in FIG.

FIG. 6 shows another embodiment of the present invention, and is a schematic configuration diagram of a direct expansion separation type three-chamber multi-refrigeration apparatus to which the present invention is applied.

FIG. 7 is an example of a control flow chart of the direct expansion separated type three-chamber multi-refrigeration apparatus shown in FIG. 6;

FIG. 8 is a schematic structural view of a direct expansion type refrigerating apparatus having a control of a ventilating apparatus according to still another embodiment of the present invention.

[Explanation of symbols]

2 indoor unit 3 outdoor unit 6 compressor 9 four-way valve 10a, 10b piping 11a, 11b, 14a, 14b, 15a, 15b on-off valve 12, 12a, 12b, 12c, 13 leak detection device 20 Control device 30 ... Ventilation device

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Kazuki Urata 502 Kandachi-cho, Tsuchiura-shi, Ibaraki Machinery Research Laboratory, Hitachi, Ltd. (56) References JP-A 1-225849 (JP, A) Shokai Sho 62 −77769 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F25B 49/02 F25B 1/00 391

Claims (6)

(57) [Claims] 1. An indoor unit having a heat exchanger and an expansion valve, and an outdoor unit having a compressor and a heat exchanger,
In a refrigeration apparatus that forms a refrigerant circuit by connecting with a gas pipe and a liquid pipe and circulates a refrigerant in the refrigerant circuit, a gas pipe open / close valve and a liquid pipe open / close valve are provided in the middle of each of the pipes. A leak detection device for detecting the leakage of the refrigerant is provided indoors and / or outdoors, and when the leakage detection device detects the leakage of the refrigerant of a predetermined value or more, the on-off valve is closed.
A method for controlling a refrigerating apparatus , comprising: a leak detecting device in a room in which an indoor unit of the refrigerating apparatus is installed.
The leak detection device detects the leakage of the refrigerant more than the specified
The liquid piping on / off valve is closed and
Operate the compressor until the suction side pressure of the compressor drops to a predetermined value.
After collecting the refrigerant in the outdoor unit, the gas piping
A method for controlling a refrigeration apparatus, comprising: 2. An indoor unit having a heat exchanger and an expansion valve.
And an outdoor unit having a compressor and a heat exchanger,
Connected by gas and liquid pipes to form a refrigerant circuit,
In a refrigeration apparatus for circulating a refrigerant in a medium circuit,
If a gas pipe opening / closing valve and a liquid pipe opening / closing valve are provided in the middle of piping,
Leak detection to detect refrigerant leakage from refrigeration equipment
Install the device indoors and / or outdoors, and make sure that the leak detection device is
When the above-described refrigerant leakage is detected, the on-off valve is closed.
A method for controlling a refrigerating apparatus, wherein the refrigerating apparatus can be switched between a cooling operation and a heating operation , a leak detection device is provided in a room in which an indoor unit of the refrigerating device is installed, and the leak detection device detects a refrigerant of a predetermined amount or more. When the leak is detected , close the liquid piping on-off valve if the refrigeration system is in cooling operation,
If the refrigeration system is in heating operation, switch to cooling operation.
At the same time, close the gas pipe on-off valve after operating the compressor to recover the refrigerant to the outdoor unit for a predetermined time or until the suction side pressure of the compressor drops to a predetermined value. the method of refrigeration apparatus said. 3. The refrigeration system in an outdoor unit or in an outdoor unit thereof.
The leakage detection device in the vicinity is provided, when the leak detection device detects the leakage of more than predetermined refrigerant, when the refrigeration apparatus of the warm tuft driver closes the liquid pipe on-off valve, also when refrigeration system cold bunch operation, with switch to warm bunch operation, close the liquid pipe on-off valve for a predetermined time, or after a suction pressure of the compressor is collected in the chamber unit refrigerant driving a compressor until reduced to a predetermined value, the gas pipe the method of the refrigeration apparatus according to claim 1 or claim 2, wherein the closing-off valve. 4. A plurality of chambers having a heat exchanger and an expansion valve.
One unit having an inner unit, a compressor and a heat exchanger
Connect the unit with gas piping and liquid piping
And a multi-system that circulates refrigerant in the refrigerant circuit
In the refrigeration system, a gas pipe opening / closing valve
And a liquid piping open / close valve and an indoor unit
Each room has a leak detection device for refrigerant, and the leak detection device
Leak was detected when leakage of refrigerant over a certain level was detected.
Connecting the indoor unit and the outdoor unit provided in the room
The method of refrigeration apparatus characterized by closing the respective opening and closing valves provided in the middle pipe. 5. A refrigeration system is switched between a cooling operation and a heating operation.
Indoor and outdoor units with indoor units installed
Detect refrigerant leakage both inside and near the
Indoor leak detection device and outdoor leak detection device
If the leak detection device and / or outdoor leak detection device
When leakage of the medium is detected, if the refrigeration system is in cooling operation,
When the liquid piping on-off valve is closed and the refrigeration system is in heating operation
Switches to cooling operation and closes the liquid piping on-off valve.
For a predetermined time or when the suction pressure of the compressor is
Operate the compressor until the temperature drops to the outdoor unit.
A method for controlling a refrigeration system, comprising closing a gas pipe opening / closing valve after collecting . 6. A ventilation device is installed in a room where an indoor unit is installed.
Installed, and the signal of the refrigerant leak detection device provided in the chamber
The feature is that the operation of the ventilation device is controlled more
The method for controlling a refrigeration apparatus according to claim 1 .