JP5622828B2 - Shield plate and air conditioner equipped with the shield plate - Google Patents

Description

  The present invention relates to a shielding plate that diffuses a refrigerant into the room and reduces the refrigerant concentration when an inflammable refrigerant leaks from the indoor unit, and an air conditioner including the shielding plate.

Considering the effects on ozone layer destruction and global warming, natural refrigerants are expected as refrigerants used in air conditioners. Examples of natural refrigerants include hydrocarbon refrigerants such as propane and isobutane, both of which are flammable and have a specific gravity of 1.80 for propane and 2.37 for isobutane, which is larger than air. If the refrigerant leaks, depending on the leakage speed and the size of the room, it may stay near the floor surface to form a combustible region, and if it encounters an ignition source, there is a risk of burning. The following techniques are disclosed as safety measures against this.
For example, when leakage of the refrigerant is detected by a sensor provided in the indoor unit, the refrigerant is discharged from an exhaust port with a damper for rotating the indoor fan to exhaust the interior of the indoor unit (for example, Patent Document 1 and Patent Document 2). ). Alternatively, when leakage of the refrigerant is detected by the sensor, the refrigerant is exhausted from the refrigerant discharge portion provided in the outdoor refrigeration cycle path (for example, Patent Document 3).

Japanese Patent No. 3291407 (page 3, FIG. 3A) JP-A-9-318208 (pages 4 to 5, FIG. 3) Japanese Patent No. 3775920 (pages 3 to 5, FIGS. 1 to 4)

The prior arts described in Patent Documents 1 to 3 are all based on the assumption that a refrigerant leak is detected by a sensor and then exhausted to the outside of the room, and the condition that the sensor can be detected with high sensitivity is satisfied. However, since the location and direction in which the refrigerant leaks cannot be specified in advance, it is difficult to detect the leaked refrigerant with high sensitivity using a sensor. Therefore, it takes time to detect refrigerant leakage, and there is a problem that the concentration becomes high during that time.
In addition, if the number of sensors is increased to make detection easier, the cost must be increased accordingly.
In addition, it is necessary to always operate the sensor even when the operation is stopped. However, if a power outage accident occurs during the air conditioner outage period, the air conditioner is not turned on and the sensor is not operated for a long time. It was also expected. If the sensor is always operated, there is a problem that the power consumption increases accordingly.

The present invention has been made to solve the problem, and in an air conditioner using a flammable refrigerant such as propane or isobutane having a specific gravity larger than that of air, when the flammable refrigerant leaks from the indoor unit when the operation is stopped. Another object of the present invention is to provide a shielding plate that suppresses sudden leakage downward of an indoor unit and prevents the refrigerant concentration below the indoor unit, particularly near the floor surface, from becoming excessively high.
It is another object of the present invention to provide a shielding plate that can ensure safety with a relatively simple configuration without consuming electric power when the operation is stopped, without using a sensor, and an air conditioner including the shielding plate.

In order to achieve the above object, a shielding plate according to the present invention is provided below an indoor unit body of an air conditioner using a flammable refrigerant having a specific gravity greater than that of air, and the indoor unit body is viewed from above. The projected area at the time is larger when the air conditioner is stopped than when the air conditioner is operated, and the top surface receives the refrigerant that flows down from the indoor unit body when the air conditioner is stopped . The refrigerant received on the upper surface is diffused.

  In order to achieve the object, an air conditioner according to the present invention includes the shielding plate of the present invention.

  As described above, the shielding plate according to the present invention is provided below the indoor unit body of the air conditioner using a flammable refrigerant having a specific gravity greater than that of air, and the indoor unit body is stopped when the air conditioner is stopped. Because the refrigerant that flows down from the inside diffuses, if the flammable refrigerant leaks from the indoor unit, the refrigerant concentration under the indoor unit is prevented from becoming excessively high, and there is a risk of ignition even if it encounters an ignition source. Can be reduced.

It is a schematic diagram which shows the state at the time of the driving | running of the air conditioning system in Embodiment 1 of this invention. It is a schematic diagram which shows the state at the time of the operation stop of the air conditioner in Embodiment 1 of this invention. It is the figure which showed the difference in the correlation of the height from a floor surface, and a refrigerant | coolant density | concentration by the magnitude of the leak rate of a refrigerant | coolant. It is a figure which shows the structure of the shielding board of the air conditioner in Embodiment 2 of this invention.

Embodiment 1 FIG.
FIG. 1 is a schematic diagram showing a state during operation of the air-conditioning system according to Embodiment 1 of the present invention.
In FIG. 1, the indoor unit main body 1 is provided with a suction port 3 for taking in indoor air, and a heat exchanger 4 is disposed inside the suction port 3. A fan 10 is disposed downstream of the heat exchanger 4, and the indoor air sucked by the rotation of the fan 10 is subjected to heat exchange by the heat exchanger 4, and then passes through the fan 10 and the air passage 11. It is supplied into the room from the air outlet 2. A shielding plate 5 is attached to the lower part of the indoor unit in a non-deployed form so as not to disturb the blown airflow during operation. In order to realize this, an angle 0 in a state in which a hanging rod 51 having a vertical longitudinal direction is attached to the lower part of the indoor unit 1 and a dividing plate 52 obtained by dividing the shielding plate 5 into two is folded. A rotating shaft 53 that is rotatably supported up to an angle of 180 degrees when the two divided plates are unfolded is provided horizontally, and the substantially center of the rotating shaft 53 is connected to the other end of the rod-shaped body 51.
The suspension unit is provided with a locking part (not shown) at the lower part of the indoor unit 1 and further provided with an engaging part (not shown) whose one end is detachably engaged with the locking part of the indoor unit 1. The rod-shaped body 51 and four chains having one end connected to one of the four corners of the upper surface of the shielding plate 5 and the other end connected to the other end of the hanging rod-shaped body 51 may be provided. .
In the figure, 6 indicates the air flow during operation.

FIG. 2 is a schematic diagram showing a state when the operation of the air conditioner in Embodiment 1 of the present invention is stopped.
In FIG. 2, the shielding plate 5 is deployed in an area approximately equal to or slightly wider than the projected area when the indoor unit body 1 is viewed from above. The shielding plate 5 has a plurality of holes 7 penetrating the upper and lower surfaces. In the figure, 8 indicates the flow of the leaked refrigerant when the refrigerant leaks.

Generally, when a refrigerant whose specific gravity is heavier than air flows down, the same refrigerant also flows around the center of the flow in the same way, so that it flows without resistance, so that it becomes a so-called laminar flow. On the other hand, the outside of the flow is subjected to resistance by dust floating in the air, nitrogen molecules and oxygen molecules constituting the air, and so-called turbulent flow, and the refrigerant falls while diffusing to the surroundings. Thereby, since the center side of the flow of the refrigerant gradually receives resistance due to the surrounding turbulent flow, the laminar flow itself becomes gradually thinner. The degree of thinning varies depending on the flow rate of the refrigerant.
FIG. 3 is a diagram showing the difference in the correlation between the height from the floor and the refrigerant concentration, depending on the refrigerant leakage speed. The solid line represents a graph when the refrigerant speed is high, and the broken line represents the refrigerant speed. The graph is shown when it is small. Here, the maximum concentration when the leakage rate is high is A%, the maximum concentration when the leakage rate is low is B%, and the lower limit concentration of combustion is C%.
In FIG. 3, when the leakage rate of the refrigerant is large, the refrigerant flows down quickly, so that the concentration near the floor surface is high, and the concentration rapidly decreases as the distance from the floor surface increases. On the other hand, when the leak rate is small, the refrigerant flows down while diffusing into the room by natural convection, so the concentration difference in the height direction is small, and even if the total leak amount is the same, the smaller the leak rate, the smaller the maximum concentration, and the combustion The risk of is small. In other words, if the leak rate is high, A> C below the height H from the floor surface, so if it encounters an ignition source, it will burn, but if the leak rate is low, B < Since it is C, it will not burn even if there is an ignition source.

Next, the operation according to the present embodiment will be described.
In the present embodiment, during operation, the air sucked from the suction port by the rotation of the fan is heat-exchanged by the heat exchanger, and supplied to the room through the fan and the air passage from the outlet.
In addition, when the operation is stopped, the shielding plate is deployed. If the refrigerant of the heat exchanger is damaged and the refrigerant leaks, the refrigerant having a specific gravity greater than that of the air leaks from the clearance of the indoor unit to the lower part of the indoor unit. Then, it flows down, but is once received by the shielding plate 5 immediately below. Here, since the area when the shielding plate is deployed is approximately equal to the projected area when the indoor unit body is viewed from above, the refrigerant is reliably received on the upper surface of the shielding plate even if it leaks from any part of the indoor unit, It does not flow down to the floor as it is. Thereafter, while the refrigerant diffuses on the upper surface of the shielding plate, it flows down through the hole to the lower side of the shielding plate, and the portion that does not flow down from the hole flows down from the four sides of the shielding plate.

As described above, in the air conditioner according to the present embodiment, when the operation is stopped, the shielding plate installed below the indoor unit is deployed, so that even if the refrigerant leaks from the indoor unit, it flows down to the floor as it is. However, once it is received by the shielding plate and diffused on the upper surface of the shielding plate, it flows down the shielding plate through the hole, and the portion that does not flow down from the hole flows down from the four sides of the shielding plate, so natural convection occurs between them. Will gradually diffuse into the room. As a result, since the refrigerant leakage speed in the region below the shielding plate is reduced, as described in FIG. 3, even if the amount of refrigerant leaking from the indoor unit is the same, The concentration can be reduced, and the risk of combustion can be reduced. In addition, it is possible to ensure safety against refrigerant leakage into the room with a relatively simple configuration without consuming electric power when the operation is stopped, without using a sensor.
In this embodiment, the shielding plate is a deployment structure attached to the lower part of the indoor unit main body. However, the shield plate is not necessarily a deployment structure as long as it does not interfere with the air flow during operation. Structure may be sufficient. Alternatively, as a separate body from the indoor unit main body, it may be directly attached to the wall surface below the indoor unit. According to these, safety can be ensured with a very simple structure and at low cost.

  The hanging rod 51 is provided with a remote controller (hereinafter abbreviated as a remote controller) of the indoor unit 1 and a remote control storage part having a through hole formed at the bottom, which is provided through the through hole. When the remote control is not stored in the remote control storage unit, the remote control is stable at a predetermined position. When the remote control is stored in the remote control storage unit, the remote control is lowered by gravity of the remote control and hits the fixing member. You may comprise so that the fixation cancellation | release mechanism which cancels | releases fixation by contacting may be provided.

Embodiment 2. FIG.
FIG. 4 is a view showing the structure of the shielding plate of the air conditioner according to Embodiment 2 of the present invention.
In FIG. 4, the shielding plate is composed of an upper plate 11 a and a lower plate 11 b that are stacked one above the other, and an interval holding member 14 that holds the upper plate 11 a and the lower plate 11 b at a predetermined interval (gap). Is provided with a plurality of holes 12a and 12b penetrating the upper and lower surfaces, and the hole positions of the upper plate and the lower plate are shifted from each other. In the figure, 13 indicates the flow of the leaked refrigerant when the refrigerant leaks.
In this case, the plurality of holes in the upper plate 11a are opened to be substantially uniform, the plurality of holes in the lower plate 11b are also opened to be substantially uniform, and when the upper plate 11a and the lower plate 11b are overlapped, Diffusion efficiency is maximized when the positions of both holes are staggered.

Next, the operation according to this embodiment will be described.
In the present embodiment, during operation, the air sucked from the suction port by the rotation of the fan is heat-exchanged by the heat exchanger, and supplied to the room through the fan and the air passage from the outlet.
In addition, when the operation is stopped, the shielding plate is deployed, and in the unlikely event that the heat exchanger piping is damaged and the refrigerant leaks, the refrigerant having a specific gravity greater than air leaks from the clearance of the indoor unit outlet to the lower side of the indoor unit. It flows down and is once received by the shielding plate. Here, since the area when the shielding plate is deployed is substantially equal to the projected area when the indoor unit body is viewed from above, the refrigerant is surely attached to the upper plate 11a of the shielding plate 11 in any part of the indoor unit. It is received on the top surface and does not flow down to the floor as it is. Thereafter, the refrigerant flows into the gap between the upper plate 11a and the lower plate 11b through the hole of the upper plate 11a while diffusing on the upper surface of the upper plate 11a of the shielding plate 11. Further, the portion that does not flow down into the gap flows down while diffusing from the four sides of the upper plate 11a. Here, since the hole of the upper plate 11a and the hole of the lower plate 11b are shifted, the refrigerant flowing into the gap between the upper plate 11a and the lower plate 11b is received by the upper surface of the lower plate 11b, While diffusing on the upper surface, it further flows down through the hole in the lower plate and below the shielding plate. Also, the portion that does not flow down from the hole flows down while diffusing from the four sides of the gap between the upper plate and the lower plate.

  As described above, in the air conditioner according to the present embodiment, the shielding plate is composed of the upper and lower plates that overlap each other and the gap between the upper and lower plates, and each plate penetrates the upper and lower surfaces. Since the hole positions of the upper plate and the lower plate are shifted from each other, the refrigerant leaked from the indoor unit is received by the shielding plate and diffused on the upper surface of the shielding plate, It flows into the gap between the upper plate and the lower plate through the hole, and flows down to the lower side of the shielding plate through the hole in the lower plate while spreading in a plane in the gap. Also, the portion that does not flow down from the hole flows down from the four sides of the upper plate or from the four sides of the gap between the upper and lower plates. In addition, since the hole positions of the upper plate and the lower plate are shifted from each other, the time during which the refrigerant stays in the shielding plate structure can be lengthened. As a result, the rate of leakage downward from the shielding plate is reduced, so that the maximum refrigerant concentration in the room can be further reduced as compared with the first embodiment, and the risk of combustion can be reduced.

In the above example, the case where the upper plate and the lower plate are configured in two stages has been described. However, the number of stages is not limited to two and may be three or more. In this case, since the residence time is further increased, the diffusion effect is improved.
Further, a foldable pedestal that supports the shielding plate 5 may be provided. This makes it easy to expand the pedestal during use to support the shielding plate 5 and to fold it out of the way when not in use.

  DESCRIPTION OF SYMBOLS 1 Indoor unit main body, 2 blower outlet, 3 suction inlet, 4 heat exchanger, 5 shielding plate, 6 air flow, 7 holes, 8 leaked refrigerant flow, 9 wall surface, 10 fan, 11 shielding plate, 11a upper plate , 11b Lower plate, 12a Upper hole, 12b Lower hole, 13 Leaked refrigerant flow, 14 Spacing member, 51 Hanging rod, 52 Dividing plate, 53 Rotating shaft.

Claims (3)

Provided below the indoor unit body of the air conditioner using a flammable refrigerant having a greater specific gravity than air,
The projected area when the indoor unit body is viewed from above is larger when the air conditioner is stopped than when the air conditioner is operating,
The shielding plate characterized in that when the operation of the air conditioner is stopped, the refrigerant flowing down from the indoor unit main body is received on the upper surface, and the refrigerant received on the upper surface is diffused. 2. The shielding plate according to claim 1, wherein the position of the air conditioner during operation is a range that does not hinder an air flow from the inside of the indoor unit main body toward the outside of the indoor unit main body.   An air conditioner comprising the shielding plate according to claim 1.

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