JP6163321B2 - Cooling system - Google Patents

Description

  The present invention provides a refrigeration system and an electrical box for controlling the refrigeration system in a machine room, and in the cooling device using a flammable gas refrigerant in the refrigeration system, the refrigeration system uses a flammable gas refrigerant (hereinafter referred to as `` The present invention relates to an ignition prevention structure that is not ignited by an electric spark (spark) that can be generated in the electrical box even if it is leaked.

  For example, in FIG. 5, a cooling device 10 such as a refrigerator or an ice making machine has a casing that is partitioned into a machine room 12 and a cooling room 18 in a vertical relationship, and a compressor 14 and a condenser disposed in the machine room 12. 16, a refrigeration system 22 in which an expansion valve 42 and the like are connected by a pipe line is configured to cool the cooler 20 disposed in the cooling chamber 18. The refrigeration system 22 employs a flammable refrigerant having a specific gravity greater than that of air such as propane or butane. The machine room 12 is provided with an electrical box 24 for performing electrical control of the refrigeration system 22, and various electrical control devices are provided inside the electrical box 24.

The combustible refrigerant is tightly sealed in the refrigeration system 22, but if it leaks out of the refrigeration system 22 for some reason, it stays near the bottom of the machine room 12 because the specific gravity is greater than that of air. Normally, since the cooling fan 44 of the condenser 16 is rotating, it is forcibly exhausted to the outside of the room. However, for example, when the fan 44 is stopped due to a failure, if the spark is generated in the electrical equipment box 24, the stagnant combustible May ignite in volatile refrigerants. That is, in the refrigeration system 22, flammable refrigerant may leak from the compressor 14, the condenser 16, and the pipes connecting the members, although rarely. The electrical box 24 accommodates a contact-type electrical control device such as a fuse or a relay. For this reason, if a spark occurs in a state where the leaked combustible refrigerant has entered the electrical box 24, the combustible refrigerant may be ignited and an unexpected situation may be caused.
As a safety measure against this, a non-contact type electric control device is used for the electrical box (Patent Document 1), or a flammable refrigerant leaked into the machine room is forcedly discharged to the outside by a cooling fan of the condenser (Patent Document 1). 2) A proposal has been made such as forming an exhaust port at the bottom of the machine room and letting a combustible refrigerant heavier than air naturally fall out of the room and be discharged (Patent Document 3).

Japanese Patent Laid-Open No. 6-137441 JP 2007-233909 A Japanese Patent No. 4876635

  However, in the safety measures disclosed in Patent Document 1, there is a problem that costs increase because electrical elements such as contactless relays are more expensive than contact-type elements. Further, in the safety measures disclosed in Patent Document 2, for example, when the cooling device is shipped and transported from the factory, when the cooling fan breaks down, or when there is a power failure, the cooling fan is not activated so that it is combustible. There is a problem that forced refrigerant cannot be forced out of the room. Furthermore, the safety measures disclosed in Patent Document 3 have a problem that an exhaust port cannot be provided at the bottom of the machine room in a type of cooling device in which a cooling room, an ice storage, or the like is provided below the machine room. There is also a proposal for an explosion-proof construction by completely sealing the electrical box itself so that safety can be ensured even if a spark blows inside the electrical box, but a heat dissipation hole is necessary to suppress internal heat generation of the storage equipment . In the case where no heat radiating hole is provided, it is necessary to take measures to sufficiently radiate heat even in a sealed type, and there is a problem that costs increase.

  Accordingly, the present invention provides a cooling apparatus that can reliably discharge the combustible refrigerant leaked from the refrigeration system into the machine room to the outside of the machine room at low cost and eliminates the possibility of the combustible refrigerant being ignited. For the purpose.

In order to solve the above-mentioned problems and achieve the intended object, the invention according to claim 1 is a compressor and a condenser disposed in a machine room partitioned around, and a cooling chamber adjacent to the machine room. a refrigeration system comprising a disposed the condenser, the the electrical equipment box is disposed for electrically controlling the refrigeration system in the machine room Rutotomoni, circulating large flammable refrigerant having a specific gravity than air in the freezing system In such a cooling device,
The electrical box is disposed at a position higher than the bottom surface of the machine room, and an air flow path is secured between the back surface of the electrical box and the bottom surface ,
The gist is that a contact-type fuse inserted in an electric system to an electric control device built in the electric box is disposed at the top of the electric box .
According to the first aspect of the present invention, even if the flammable refrigerant leaks from the refrigeration system and stays in a layered manner at the bottom of the machine room, the electrical box that may cause a spark is above the stagnation area of the flammable refrigerant. Therefore, even if a spark occurs, the combustible refrigerant will not ignite.
In addition, since the contact type fuse that may cause a spark is located at the top of the electrical box, that is, at the highest position, the flammable refrigerant leaking from the refrigeration system does not come into contact with the fuse, and the ignition The danger can be completely prevented.

Invention of claim 2, the lower side wall portion partitioning the machine room, exhaust port opened to the outside in communication with the air passage is opened, the flammable refrigerant which has leaked from the refrigeration system The gist is that the exhaust is discharged to the outside through the exhaust port.
According to the second aspect of the present invention, even if the flammable refrigerant leaks from the refrigeration system and stays at the bottom of the machine room, it is discharged from the exhaust port communicating with the air flow passage to the outside, so that safety is ensured. The

The gist of the invention described in claim 3 is that a plurality of the exhaust ports are provided in the lateral direction or the vertical direction so as to reach at least a position higher than the top of the electrical box in the side wall portion of the machine room. .
According to the invention of claim 3, the exhaust port not only opens corresponding to the air flow path between the back surface of the electrical box and the bottom of the machine room, but also opens to a position higher than the top of the electrical box. Therefore, the combustible refrigerant leaks and is immediately discharged outside the room.

According to a fourth aspect of the present invention, a lead-in port for various wirings connected to the electric control device is formed on the back surface of the electrical box, and an opening edge of the lead-in port has a gap between the various wirings. Then, the gist is that the combustible refrigerant that has entered the electrical box is discharged from the inlet.
According to the invention of claim 4 , even if the combustible refrigerant leaked from the refrigeration system enters the electrical equipment box through the heat radiation hole, the specific gravity of the combustible refrigerant is larger than that of the air, so It can be quickly discharged out of the electrical box by gravity from the opening of the opening.

  According to the present invention, since the electrical equipment box disposed in the machine room exists at a position higher than the bottom surface of the machine room, even if the flammable refrigerant leaks from the refrigeration system and stays on the bottom surface of the machine room, the spark is generated. Since it is spatially isolated from the electrical equipment box that is the source, it has a beneficial effect that can eliminate the possibility of ignition.

It is a right view of a large sized refrigerator, Comprising: The machine room of the housing | casing upper part is partially broken and shown. It is a front longitudinal cross-sectional view of the housing | casing upper part shown by the II-II line cross section of FIG. It is a plane sectional view showing the inside of the machine room of the upper part of the case in a refrigerator. It is a side view of the electrical equipment box mounted on the support stand. It is a right view which cuts and shows the cooling device which concerns on a prior art partially.

  A preferred embodiment of the cooling device according to the present invention will be described below. Since the basic configuration of the cooling device has been described with reference to FIG. 5, the same or similar members are denoted by the same reference numerals as those used in FIG. In addition, as a cooling device to which the present invention is applied, there are a refrigerator, a fully automatic ice maker, and a freezer showcase, but in addition, a cooling / heating chamber in which a cooling mechanism and a heating mechanism coexist may be used. In the illustrated embodiment, a case where a large refrigerator for business use is adopted as a cooling device will be described.

  FIG. 1 is a right side view of the large-sized refrigerator 10 and shows a partially cutaway machine room 12 at the top of the housing. FIG. 2 is a front longitudinal sectional view of the upper part of the housing shown by a cross section taken along line II-II in FIG. FIG. 3 is a plan sectional view showing the inside of the machine room 12 in the upper part of the housing of the refrigerator 10.

  As shown in FIGS. 1 and 2, the casing 40 of the refrigerator 10 is divided into a machine room 12 defined at the upper part and a cooling room 18 defined at the lower part of the machine room 12. The cooling chamber 18 functions as a storage chamber for vegetables and the like, and a cooler 20 that forms a part of the refrigeration system 22 is disposed inside and above. A compressor 14, a condenser 16, an expansion valve 42, and the like are connected to the machine chamber 12 at the upper part of the casing through pipe lines, and further connected to a cooler 20 disposed in the cooling chamber 18 at the lower part of the casing. A system 22 is configured. A cooling fan 44 is provided behind the condenser 16, and external air is sucked from an opening 48 such as a louver provided in the side wall 46 near the condenser in the machine room 12, so that the condenser 16 and the compressor 14 is cooled, and the waste heat after heat exchange is discharged to the outside through an exhaust port 30 provided in the side wall 28 of the machine room opposite to the louver opening 48. The exhaust port 30 will be further described later.

  The electrical box 24 is disposed inside the machine room 12. As shown in FIG. 4, the electrical box 24 is provided with an electrical control device 32 for electrically controlling the refrigeration system 22 and a plurality of heat radiation holes (not shown) on the side of the box. Has been established and itself has a conventional structure.

  In this embodiment, the electrical box 24 disposed in the machine room 12 is provided at a portion raised by a required height from the bottom surface 12a of the machine room 12, as shown in FIG. That is, a support base 50 having a required height is provided on the bottom surface 12 a of the machine room 12, and the electrical box 24 is placed and supported on the support base 50. The reason why the support base 50 having the required height is used in this way is that there is a possibility that a spark may be generated even if a flammable refrigerant leaks from the refrigeration system 22 and stays on the bottom surface 12a of the machine room 12. The electrical box 24 incorporating the control device 32 is located above the flammable refrigerant retention area, so that there is no risk of ignition even if a spark occurs. Therefore, the height of the support 50 (in other words, the back surface 24a of the electrical box 24) and the bottom surface 12a of the machine room 12 is higher than the height of the stagnation area where the flammable refrigerant leaked from the refrigeration system 22 is accumulated in the bottom surface 12a. Bigger is better.

  Further, in this embodiment, as shown in FIG. 2, an air flow passage 26 is defined between the lower part (support base 50) of the electrical box 24 and the bottom surface 12 a of the machine room 12, and communicates with the air flow passage 26. The exhaust port 30 through which the combustible refrigerant can be discharged to the outside of the room is opened in the side wall portion 28 of the machine room 12. As a result, even if the flammable refrigerant leaks from the refrigeration system 22, the flammable refrigerant can be reduced by the exhaust port 30 communicating with the air flow passage 26 between the electrical box 24 and the bottom surface 12a of the machine room 12. As the cooling fan 44 blows, the air is quickly discharged outside the room. Even if the cooling fan 44 is stopped, the combustible refrigerant does not stagnate inside the machine room 12 at a high density due to the presence of the exhaust port 30.

  The exhaust port 30 opened in the side wall portion 28 is not limited to the portion corresponding to the air flow passage 26 between the lower portion (support base 50) of the electrical equipment box 24 and the bottom surface 12a of the machine room 12, as shown in FIG. And as shown in FIG. 2, it is desirable to form as several slit-shaped opening extended in the horizontal direction or an up-down direction over the area | region exceeding the upper surface height of the electrical equipment box 24. As shown in FIG. In this case, as shown in FIG. 3, it is more preferable to provide a necessary gap between the electrical box 24 and the side wall 28 of the machine room 12 from the viewpoint of promoting air circulation in the machine room 12.

  By the way, from the viewpoint of electrical safety standards, the electrical box 24 is obliged to install a fuse that melts and breaks the circuit when overcurrent occurs. This fuse needs to be replaced if it is blown or deteriorated, but it is difficult to adopt an explosion-proof structure that seals the charging part, such as a contactless relay, because it is detachably fitted to the charging part of the fuse holder. It is. For this reason, even if the non-contact of the elements in the electric control device 32 built in the electrical box 24 is prevented to prevent the occurrence of spark, only the fuse is not made non-contact and the charged part remains exposed. Therefore, sometimes a spark is caused by an electrical short circuit in the fuse portion, and this may become a flammable source of the leaked combustible refrigerant.

  Therefore, in this embodiment, instead of making the fuse non-contact, as shown in FIGS. 2 and 4, the conventional fuse 34 is arranged at the top of the electrical box 24, so that the combustible refrigerant can be prevented. Eliminates fear of ignition. That is, the fuse holder 52 inserted in the electric system connected to the electric control device 32 built in the electrical equipment box 24 is disposed at the top of the electrical equipment box 24, and the fuse 34 is detachably fitted into the fuse holder 52. It is what I did. Since the fuse 34 exposed in this way is disposed at the top of the electrical box 24, the flammable refrigerant leaks from the refrigeration system 22 and stays in the lower part of the electrical box 24 in the machine room 12. However, since a sufficient distance is secured from the fuse 34 serving as a spark generation source, safety is improved. In addition, since the visibility by the operator at the time of periodic inspection and the like is increased, the serviceability is also improved.

  In addition, as described above, the electrical box 24 has a large number of heat radiation holes on the side wall of the box for heat radiation. Therefore, the flammable refrigerant leaking from the refrigeration system 22 may enter the inside of the electrical box 24 through the heat radiating holes (not shown). Therefore, a lead-in port 38 is opened at the bottom of the electrical box 24, the wiring 36 is drawn from the pull-in port 38, and the diameter of the pull-in port 38 is set to a sufficient size. Even if the flammable refrigerant enters, the flammable refrigerant is discharged from the inlet 38 to the outside of the electrical box 24 by its own weight.

  The electrical control device 32 built in the electrical box 24 includes a control board such as a sequencer, a control relay, and the like, but includes an inverter element when the control target is an inverter motor. Since this inverter element is a switching element that turns on and off the switch at a high speed, the inverter element becomes high temperature. Therefore, it is necessary to promote heat dissipation of the electrical box 24. Therefore, as shown in FIG. 2 and FIG. 4, good heat dissipation is promoted by closely arranging the shielding plates 54 on the upper surface and side surfaces of the electrical equipment box 24.

  In FIG. 2, depending on the installation environment of the refrigerator, condensation may occur on the internal ceiling of the machine room 12. As this condensation proceeds, water droplets are dripped into the machine room 12, but the electrical equipment box 24 dislikes moisture, so it is necessary to protect against the falling water droplets. In such a case, if the shielding plate 54 is inclined obliquely above the electrical box 24 as shown in FIGS. 2 and 4, water drops from the ceiling of the machine room 12 fall on the shielding plate 54. However, since it flows diagonally and drops to the side of the electrical box 24, it is preferable.

10 cooling device, 12 machine room, 12a bottom surface, 14 compressor, 16 condenser,
18 cooling chamber, 20 cooler, 22 refrigeration system, 24 electrical box, 24a backside,
24b Top part, 26 Air flow passage, 28 Side wall part, 30 Exhaust port, 32 Electrical control device 34 Fuse, 36 Wiring, 38 Inlet port

Claims (4)

Compressor (14) and condenser (16) disposed in a machine room (12) partitioned around, and a cooler (20) disposed in a cooling chamber (18) adjacent to the machine room (12) a refrigeration system (22) consisting of said machine chamber (12) the electrical component box for electrically controlling a refrigeration system (22) (24) is disposed Rutotomoni, from air to the refrigeration system (22) In the cooling device (10) configured to circulate a flammable refrigerant having a large specific gravity,
The electrical box (24) is disposed at a position higher than the bottom surface (12a) of the machine room (12), and air flows between the back surface (24a) of the electrical box (24) and the bottom surface (12a). Road (26) is secured ,
A contact-type fuse (34) inserted into the electrical system to the electrical control device (32) built in the electrical box (24) is disposed at the top (24b) of the electrical box (24). A cooling device characterized by the above. The machine room (12) side walls defining a downwardly of (28), said air flow passage (26) communicates with an opening to the outside air outlet (30) is opened, leakage from the refrigeration system (22) The cooling device according to claim 1, wherein the combustible refrigerant discharged is discharged to the outside through the exhaust port (30).   A plurality of the exhaust ports (30) are provided in the lateral direction or the vertical direction so as to reach at least a position higher than the top of the electrical box (24) in the side wall portion (28) of the machine room (12). 3. The cooling device according to 1 or 2. On the back surface (24a) of the electrical box (24), a service port (38) for various wirings (36) connected to the electrical control device (32) is formed, and the opening edge of the service port (38) with a gap between the various wires (36), wherein the flammable refrigerant which has entered into the electric component box (24) to any one of claims 1 to 3 which is discharged from the service entrance (38) of the cooling device.

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