JP7340215B2 - cooling system - Google Patents

Description

TECHNICAL FIELD The present invention relates to cooling systems.

Conventionally, fluorocarbon gas has been used as a refrigerant in freezing and refrigeration equipment. However, in recent years, environmental issues such as global warming and ozone layer depletion have been in the spotlight, and the international community has begun to come together to tackle environmental issues, such as the 1997 Kyoto Protocol and the 2015 Paris Agreement. Against this background, development of refrigerants that do not contain fluorine (fluorocarbon-free refrigerants) and research and development of cooling systems using fluorocarbon-free refrigerants are progressing (for example, Patent Document 1).

JP 2017-67393 Publication

Hydrocarbons such as carbon dioxide, ammonia, and propane are known as non-fluorocarbon refrigerants. However, in the case of carbon dioxide and ammonia, the cost of installing a circulation mechanism (pipes, etc.) for circulating the refrigerant becomes high. Furthermore, in the case of hydrocarbons such as propane, there is a problem of flammability. For this reason, the spread of cooling systems using CFC-free refrigerants has been delayed.

In view of these circumstances, the present invention aims to provide a cooling system using a non-fluorocarbon refrigerant that is inexpensive to introduce.

The cooling system of the present invention includes: a refrigerator having a housing space for storing refrigerated products; a compressor disposed in an external space of the refrigerator; an evaporator disposed in the housing space; A refrigerant feed pipe that sends a flammable refrigerant to the evaporator, a refrigerant return pipe that returns the refrigerant from the evaporator to the compressor, an exhaust fan disposed below in the accommodation space, and a refrigerant return pipe provided in the refrigerant feed pipe. a sending-side valve mechanism provided in the refrigerant return pipe; a return-side valve mechanism provided in the refrigerant return pipe; a refrigerant leak sensor that detects leakage of the refrigerant; and a control unit that controls each part. The controller is configured to control a diffusion state in which the exhaust fan is driven and the sending-side valve mechanism and the return-side valve mechanism are closed, and a diffusion state in which the exhaust fan is driven and the sending-side valve mechanism and the return-side valve are closed. The controller is capable of switching between a non-diffusion state in which the mechanism is open, and a non-diffusion state in which the mechanism is open, and the control unit sets the state to the diffusion state when the leakage amount detected by the refrigerant leakage sensor is equal to or greater than a predetermined value, and sets the state to the diffusion state when the leakage amount is a predetermined value. If it is less than 1, the non-diffusion state is set, and the sending-side valve mechanism and the return-side valve mechanism connect the outer valve located in the external space of the cooling warehouse and the inner valve located in the accommodation space. and the control unit is configured to stop the compressor and close both of the outer valves and both of the inner valves when the leakage amount detected by the refrigerant leakage sensor is equal to or greater than a predetermined value; Between the refrigerator and the compressor, the refrigerant feed pipe and the refrigerant return pipe are exposed to the external space of the refrigerator, and the control unit controls the refrigerant flow rate when the leakage amount detected by the refrigerant leak sensor is equal to or higher than a threshold value. The external space is an outdoor space, and the cooling store is a refrigerator or a freezer in which an opening is formed through which people can enter and exit, and the opening is provided with a door. The refrigerant leak sensor is provided only in the housing space of the refrigerator. The cooling system of the present invention also includes a refrigerator having a storage space for storing refrigerated products, a compressor disposed in an external space of the refrigerator, an evaporator disposed in the storage space, and a compressor disposed in the storage space. a refrigerant feed pipe for sending flammable refrigerant from the evaporator to the evaporator, a refrigerant return pipe for returning the refrigerant from the evaporator to the compressor, an exhaust fan disposed below in the housing space, and the refrigerant feed pipe. a sending-side valve mechanism provided in the refrigerant return pipe; a return-side valve mechanism provided in the refrigerant return pipe; a refrigerant leak sensor that detects leakage of the refrigerant; and a control unit that controls each part. It is heavier than air, and the control unit controls the diffusion state in which the exhaust fan is driven and the sending valve mechanism and the return valve mechanism are closed, and the exhaust fan is stopped and the sending valve mechanism and the return valve mechanism are closed. The controller is capable of switching between a non-diffusion state in which the side valve mechanism is open, and a non-diffusion state in which the leakage amount detected by the refrigerant leakage sensor is greater than or equal to a predetermined value. If it is less than a predetermined value, the non-diffusion state is established, and the sending valve mechanism and the returning valve mechanism are configured to connect an outer valve located in the external space of the refrigerator and an inner valve located in the storage space. , and when the leakage amount detected by the refrigerant leakage sensor is equal to or greater than a predetermined value, the control unit stops the compressor, closes both the outer valves, and then closes both the inner valves. Between the refrigerator and the compressor, the refrigerant feed pipe and the refrigerant return pipe are exposed to the external space of the refrigerator, and the control unit is configured to control the amount of leakage detected by the refrigerant leak sensor. If the threshold value is exceeded, an alarm is output. or a freezer, and the refrigerant leak sensor is provided only in the storage space of the refrigerator.

According to the present invention, since the flammable refrigerant system is located outdoors, the cost of introducing a fluorocarbon-free refrigerant cooling system is reduced. As a result, the introduction of cooling systems using CFC-free refrigerants will become widespread, which will eventually lead to solutions to environmental problems such as global warming and ozone layer depletion.

FIG. 1 is a perspective view showing an overview of a cooling system. FIG. 2 is a perspective view showing an outline of a storage space of the refrigerator. FIG. 2 is a plan view showing an outline of the arrangement of components of the cooling system.

As shown in FIGS. 1 to 3, the cooling system 2 includes a refrigerator 10 having a storage space SK for storing refrigerated items M, a compressor 20 arranged in the external space of the refrigerator 10, and a compressor 20 arranged in the storage space SK. It includes an evaporator 30, a refrigerant feed pipe 41 that sends flammable refrigerant from the compressor 20 to the evaporator 30, a refrigerant return pipe 42 that returns refrigerant from the evaporator to the compressor 20, and a control unit 80.

The refrigerator 10 includes an opening for people to enter and exit, and for loading and unloading refrigerated items M, and a door D provided in the opening. The opening can be freely switched by the door D between an open state in which the accommodation space SK and the external space communicate with each other, and a closed state in which the accommodation space SK and the external space are disconnected. A refrigerant feed pipe 41 and a refrigerant return pipe 42 between the refrigerator 10 and the compressor 20 are exposed to the external space.

The refrigerant is a flammable refrigerant, and is classified as flammable according to the high pressure method as of February 2014. Among refrigerants, those heavier than air are preferred, such as hydrocarbons (propylene, propane, butane, etc.).

The control unit 80 includes an operation section for operating each section, a control section for controlling each section according to the operation section and a built-in program, and an output section for notifying alarms and displaying the status of each section. A refrigerant circulation path is formed between the compressor 20 and the evaporator 30 by the refrigerant feed pipe 41 and the refrigerant return pipe 42 .

Furthermore, the cooling system 2 includes a refrigerant leak sensor 51 that detects refrigerant leakage, a temperature sensor (not shown) that detects the temperature of the accommodation space SK, an exhaust fan 54 disposed below in the accommodation space SK, and a temperature sensor (not shown) that detects the temperature of the accommodation space SK. It includes an air supply fan 55 disposed above in the space SK, a feed side valve 61 provided on the refrigerant feed pipe 41, and a return side valve 62 provided on the refrigerant return pipe 42.

It is preferable that a plurality of refrigerant leak sensors 51 are arranged in the accommodation space SK. The refrigerant leak sensor 51 can be installed under the refrigerant circulation path (for example, the evaporator 30), near the refrigerant circulation path (for example, the evaporator 30), near the exhaust fan 54, near the air supply fan 55, etc. be. As the refrigerant leak sensor 51, a concentration sensor capable of detecting the concentration of refrigerant can be used. A plurality of temperature sensors are preferably arranged in the housing space SK, and may be arranged near the refrigerant leakage sensor 51.

The exhaust fan 54 is for sending out the gas in the housing space SK to the outside space of the refrigerator 10, and the air supply fan 55 is for sending the gas in the outside space of the refrigerator 10 to the housing space SK. The exhaust fan 54 and the air supply fan 55 can reduce the concentration of refrigerant in the accommodation space SK. It is preferable that the exhaust fan 54 is placed at a lower position than the air supply fan 55. The exhaust fan 54 is preferably provided at a position facing the refrigerant circulation path. For example, if the refrigerant circulation path is provided on an inner wall of the refrigerator 10, the exhaust fan 54 is preferably provided on an inner wall facing the inner wall. The air supply fan 55 may be arranged to face the exhaust fan 54, or may be arranged between the refrigerant circulation path and the exhaust fan 54, as shown. Furthermore, the air suction direction D54 by the exhaust fan 54 preferably intersects, and preferably perpendicularly, the air supply direction D55 by the air supply fan 55.

The sending valve 61 includes an outer sending valve 61G located outside the refrigerator 10 and an inner sending valve 61N located in the accommodation space SK. Similarly, the return valve 62 includes an outer return valve 62G located outside the refrigerator 10 and an inner return valve 62N located in the accommodation space SK.

Control unit 80 reads sensing data from each sensor 51. Furthermore, the control unit 80 operates and stops each of the fans 53 to 54, opens and closes each of the valves 61 to 62, and so on.

Next, how to use the cooling system 2 will be explained.

The control unit 80 reads sensing data from the refrigerant leak sensor 51, and compares the value of the sensing data with a preset threshold value (for example, 10% LEL; LEL: lower explosion limit). If the read value is less than the threshold, each valve 61 to 62 is opened under the control of the control unit 80, the compressor 20 and evaporator 30 are operated, and each fan 54 to 55 is stopped (non-diffusion situation). Therefore, the refrigerant circulates through the refrigerant circulation path, the refrigerant is compressed in the compressor 20, and the compressed refrigerant absorbs surrounding heat and evaporates in the evaporator 30. As a result, the refrigerated items M accommodated in the accommodation space SK are cooled.

On the other hand, the control unit 80 compares the value of the sensing data with the threshold value, and if the read value is greater than or equal to the threshold value, each valve 61 to 62 is closed under the control of the control unit 80, and the compressor 20 and The evaporator 30 is stopped, and each of the fans 54 to 55 is operated (diffusion state). As a result, the gas in the accommodation space SK is exhausted to the external space of the refrigerator 10. Therefore, when refrigerant leaks, the gas in the storage space SK is exhausted to the outside space of the refrigerator 10, so that flammable refrigerant does not remain in the storage space SK. Therefore, the risk of ignition or the like due to leakage of flammable refrigerant can be reduced.

Note that when the value of the sensing data is equal to or greater than the threshold value, each valve 61 to 62 is closed under the control of the control unit 80. However, the order in which the valves 61 to 62 are closed is as follows: After the valve 62G is closed, it is preferable to close the sending inner valve 61N and the return inner valve 62N. Further, after transitioning to the diffusion state, the control unit 80 compares the value of the sensing data with the threshold value, and if the value of the sensing data is less than the threshold value, the control unit 80 controls each part to prevent diffusion. It is better to make it a state. At this time, the order in which the valves 61 to 62 are opened is that after the inner valve 61N on the sending side and the inner valve 62N on the return side are opened, the outer valve 61G on the sending side and the outer valve 62G on the return side are opened. good.

Preferably, the control unit 80 stores sensing data from the refrigerant leak sensor 51 and the temperature sensor in a built-in storage medium. Thereby, in the diffusion state, it can be determined whether the temperature inside the refrigerator 10 is equal to or higher than a predetermined threshold value. Thereby, the quality of the stored refrigerated items M can be controlled. Note that it is preferable to set the threshold value of the concentration of the refrigerant in anticipation of a temperature rise in the diffusion state.

When the value of sensing data from the refrigerant leak sensor 51 or the temperature sensor exceeds a threshold value, the control unit 80 may output an alarm to notify that fact.

Although the above embodiment has been described as a refrigerator, the present invention is not limited to refrigerators, but can also be applied to cooling systems such as freezers and air conditioners.

Preferably, the exhaust fan 54 is provided with an exhaust duct 64. Preferably, the exhaust duct 64 extends to a location with good ventilation. Thereby, the gas inside the refrigerator 10 can be diffused into the external space.

Note that the cooling system 2 may include a pump for sending refrigerant. The pump is preferably arranged in the refrigerant feed pipe 41 or the refrigerant return pipe 42. The pump may be installed either outside the refrigerator 10 or in the housing space SK, but the outside space of the refrigerator 10 is preferable. The control unit 80 can operate and stop the pump, and may operate the pump in a non-diffusion state and stop the pump in a diffusion state.

It should be noted that the present invention is not limited to the embodiments described above, and it goes without saying that various changes can be made without departing from the gist of the present invention.

2 Cooling system 10 Refrigerator 20 Compressor 30 Evaporator 41 Refrigerant feed pipe 42 Refrigerant return pipe 51 Refrigerant leak sensor 54 Exhaust fan 55 Air supply fan 61 Sending side valve 61G Sending side outer valve 61N Sending side inner valve 62 Return side valve 62G Return Outer valve 62N Return inner valve 64 Exhaust duct 80 Control unit

Claims (2)

A refrigerator having a storage space for storing refrigerated items;
a compressor arranged in an external space of the cooling warehouse;
an evaporator arranged in the accommodation space;
a refrigerant feed pipe that sends flammable refrigerant from the compressor to the evaporator;
a refrigerant return pipe that returns the refrigerant from the evaporator to the compressor;
an exhaust fan disposed below in the accommodation space;
a sending-side valve mechanism provided in the refrigerant sending pipe;
a return side valve mechanism provided in the refrigerant return pipe;
a refrigerant leak sensor that detects leakage of the refrigerant;
A control unit that controls each part,
the refrigerant is heavier than air;
The control unit is configured to control a diffusion state in which the exhaust fan is driven and the sending valve mechanism and the return valve mechanism are closed, and a diffusion state in which the exhaust fan is stopped and the sending valve mechanism and the return valve mechanism are open. It can be freely switched between the non-diffusion state and
The control unit sets the refrigerant to the diffusion state when the leakage amount detected by the refrigerant leakage sensor is equal to or greater than a predetermined value, and sets the non-diffusion state when the leakage amount is less than a predetermined value,
The sending side valve mechanism and the returning side valve mechanism are
an outer valve located in the outer space of the refrigerator;
and an inner valve located in the accommodation space,
The control unit stops the compressor and closes both the outer valves and both the inner valves when the leakage amount detected by the refrigerant leakage sensor is equal to or greater than a predetermined value,
Between the refrigerator and the compressor, the refrigerant feed pipe and the refrigerant return pipe are exposed to an external space of the refrigerator,
The control unit outputs an alarm when the leakage amount detected by the refrigerant leakage sensor is equal to or greater than a threshold value,
The external space is an outdoor space,
The cooling store is a refrigerator or a freezer in which an opening is formed through which people can enter and exit, and the opening is provided with a door;
A cooling system characterized in that the refrigerant leakage sensor is provided only in the accommodation space of the refrigerator . A refrigerator having a storage space for storing refrigerated items;
a compressor arranged in an external space of the cooling warehouse;
an evaporator arranged in the accommodation space;
a refrigerant feed pipe that sends flammable refrigerant from the compressor to the evaporator;
a refrigerant return pipe that returns the refrigerant from the evaporator to the compressor;
an exhaust fan disposed below in the accommodation space;
a sending-side valve mechanism provided in the refrigerant sending pipe;
a return side valve mechanism provided in the refrigerant return pipe;
a refrigerant leak sensor that detects leakage of the refrigerant;
A control unit that controls each part,
the refrigerant is heavier than air;
The control unit is configured to control a diffusion state in which the exhaust fan is driven and the sending valve mechanism and the return valve mechanism are closed, and a diffusion state in which the exhaust fan is stopped and the sending valve mechanism and the return valve mechanism are open. It can be freely switched between the non-diffusion state and
The control unit sets the refrigerant to the diffusion state when the leakage amount detected by the refrigerant leakage sensor is equal to or greater than a predetermined value, and sets the non-diffusion state when the leakage amount is less than a predetermined value,
The sending side valve mechanism and the returning side valve mechanism are
an outer valve located in the outer space of the refrigerator;
and an inner valve located in the accommodation space,
The control unit is configured to stop the compressor and close both of the inner valves after closing both of the outer valves when the leakage amount detected by the refrigerant leakage sensor is equal to or greater than a predetermined value;
Between the refrigerator and the compressor, the refrigerant feed pipe and the refrigerant return pipe are exposed to an external space of the refrigerator,
The control unit outputs an alarm when the leakage amount detected by the refrigerant leakage sensor is equal to or greater than a threshold value,
The external space is an outdoor space,
The cooling store is a refrigerator or a freezer in which an opening is formed through which people can enter and exit, and the opening is provided with a door;
A cooling system characterized in that the refrigerant leakage sensor is provided only in the accommodation space of the refrigerator .

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