JP6519047B1 - A method for preventing the reduction of the service life of an outdoor switchboard - Google Patents

Abstract

The present invention provides a method for prolonging the life of an internal switchboard of an outdoor switchboard, extending the life of a ventilation fan, improving space efficiency and reducing manufacturing costs, and providing a method for preventing the lifespan of the outdoor switchboard from being adversely affected. about. A switchboard body (1) installed outdoors and affected by a plurality of heat sources, an internal device accommodated inside the switchboard body, and a temperature in the switchboard body provided in the vicinity of a ceiling inside the switchboard body A method for preventing the service life of the switchboard for outdoor use having a ventilation fan 4 which starts operating when the temperature exceeds a predetermined temperature, applying a heat insulating paint to the outer surface of the switchboard body to raise the temperature inside the switchboard body; In particular, alleviating the temperature rise inside the roof delays the time for the temperature inside the switchboard body to reach the predetermined temperature and reduces the operating time of the ventilation fan, thereby preventing the life of the internal equipment and the ventilation fan from being reduced. How to prevent the service life of outdoor switchboards from decreasing. [Selected figure] Figure 1

Description

  An embodiment of the present invention relates to a method for preventing the decrease in life of an outdoor switchboard.

  Conventionally, various devices are accommodated inside a switchboard or the like, and the environment in the switchboard needs to be adapted to the installation conditions of these internal devices. In recent years, consideration has been given to the installation environment of internal devices, due to the increase in density of internal devices and digital circuits, and the increase in average temperature due to global warming, etc. The fact is that it has not changed. As the installation environment factor of the internal equipment of the switchboard, the temperature, humidity etc. inside the switchboard can be considered, and the exhaust heat is performed for the purpose of preventing the breakdown and the life reduction of the internal equipment.

  In particular, in the switchboard installed outdoors, in addition to the temperature rise due to heat generation of the internal equipment, it is necessary to consider the temperature rise inside the switchboard due to solar radiation. In addition, the switchboards are often installed on the roof of the building together with the outdoor units of the air conditioning equipment in the central area of the city, and the heat island phenomenon is also affecting the installation environment.

  In order to cope with such an installation environment, as a heat removal method of the switchboard installed outdoors, one having a ventilation fan installed, one having a cooling device such as a cooler installed, and the radiation heat due to solar radiation shown in Patent Document 1 below. It has been proposed to provide a light shielding plate for prevention.

Next, as these conventional heat removal methods, a method using a ventilation fan will be described with reference to FIG. 4, a method using a cooling device as FIG. 5, and a method using a light shielding plate with reference to FIGS.
FIG. 4 is a side view of an outdoor switchboard equipped with a ventilation fan. In FIG. 4, 1 is a box-like switchboard main body, 2 is a charge inlet, 3 is a roof, 4 is a ventilation fan, 5 is a ventilation fan housing box, 6 is a temperature sensor installed inside the switchboard body 1, 7 is a switchboard body 1 Door 8 is a side plate. In addition, the internal equipment accommodated in the switchboard is omitted.

  The door 7 is provided on the front and back of the switchboard main body 1 and the air supply port 2 is provided at the lower part. A ventilation fan storage box 5 having a waterproof function is provided on the top surface of the roof 3. The ventilation fan 4 housed in the ventilation fan housing box 5 starts operation when the measurement value of the temperature sensor 6 reaches a predetermined temperature, and is controlled to ventilate the air in the panel to satisfy the installation condition of the internal equipment. This heat removal method is called forced ventilation type.

  FIG. 5 is a side view of an outdoor switchboard provided with a cooling device. In FIG. 5, 1 is a switchboard main body, 3 is a roof, 7 is a door of the switchboard main body 1, 8 is a side plate, and 9 is a cooling device (cooler) provided on the door surface of the switchboard main body 1. The internal equipment housed in the switchboard is omitted. The cooling device 9 starts its operation when the measurement value of the temperature sensor 6 reaches a predetermined temperature, and is controlled so as to satisfy the installation condition of the internal equipment by cooling the air in the panel. This heat removal method is called sealed forced cooling type.

  Fig.6 (a) is a front view of the outdoor switchboard provided with the light-shielding plate, FIG.6 (b) is the side view, FIG.6 (c) is YY sectional drawing of Fig.6 (a). 7 is a cross-sectional view taken along the line X-X of FIG.

  6 (a) to 6 (c) and FIG. 7, 1 is a switchboard main body, 3 is a roof, 7 is a door, 7A is a door light shielding plate, 8 is a side surface plate, 8A is a side light shielding plate, 10 is a spacing member, 11 is a convection space. The internal equipment housed in the switchboard is omitted. The door 7 and the door light shielding plate 7A, and the side plate 8 and the side light shielding plate 8A are attached via the spacing members 10, respectively, and a convection space 11 is provided between them to take measures against radiation heat due to solar radiation.

Japanese Utility Model Publication No. 61-114909

  In the conventional forced ventilation type heat removal method using the ventilation fan described above, the air inside the outdoor switchboard is forcibly replaced by the ventilation fan 4 to perform heat removal. However, when the ventilation fan 4 is broken due to the life, etc., natural convection can be expected, but the necessary amount of exhaust heat can not be obtained, and the internal temperature of the switchboard body 1 exceeds the corresponding temperature of the internal equipment. Moreover, the roof 3 on which the ventilation fan 4 is installed is a part that is greatly affected by the radiation heat from the sun from the sun, and may exceed 60 ° C. on a sunny day in summer. The life of the general ventilation fan 4 depends on the performance of the motor bearing grease, but as shown in the graph in FIG. 8, the life of the ventilation fan is about 40,000 h at 60 ° C. at an ambient temperature of 50 ° C. If it exceeds, the life is further reduced to about 30,000 h or less.

  As described above, there is a problem that the life of the ventilation fan 4 is reduced when the temperature of the roof 3 which is the installation place of the ventilation fan 4 which is a key of the forced ventilation type temperature control becomes high. In addition, when the internal temperature of the switchboard main body 1 rises to a temperature higher than the corresponding temperature of the internal devices, there is also a possibility of inducing a decrease in the lifetime of the internal devices or a failure. Furthermore, when the switchboard is installed in the vicinity of a residential area, the noise at the time of operating the ventilation fan 4 also becomes a problem.

  Further, in the conventional sealed forced cooling type exhaust heat method using a cooling device, the air inside the switchboard body 1 is cooled by the cooling device 9 such as a cooler. However, if the cooling device 9 is broken due to the service life or the like, it can not be cooled and the internal temperature of the switchboard main body 1 will exceed the installation conditions of the internal devices. Moreover, since the inside of the switchboard body 1 is sealed, ventilation due to natural convection can not be expected, and the temperature rise inside the switchboard body 1 at the time of failure of the cooling device 9 becomes very large. There has been a problem that it causes a decrease in the life of the device and a failure.

  Furthermore, in addition to the fact that the cooling device 9 is expensive compared to the ventilation fan 4, it is also a problem that the power consumption is large. When exhaust heat and cooling of about 1500 W are assumed, the exhaust fan 4 is capable of exhausting heat with about 100 W of power, whereas the cooling device 9 requires about 600 W of electric power. Furthermore, there is also an environmental problem when fluorocarbon gas is used as the refrigerant used for cooling. From such a circumstance, the forced ventilation type described above is mostly applied to the exhaust heat of the outdoor switchboard.

  Next, according to the conventional heat removal method using the light shielding plate described above, as shown in FIG. 7, when the door 7 is opened, the door light shielding plate 7A is also opened together. There is a possibility that the plate 7A and the side light shielding plate 8A may interfere with each other when the door is opened. If the door opening angle is reduced to prevent interference, the maintainability deteriorates, and conversely, if it is intended to secure the door opening angle as necessary, the size of the door light shielding plate 7A needs to be smaller than the door 7, Has a problem in that it is impossible to obtain good thermal insulation performance.

  In addition, by installing the light shielding plates 7A and 8A, the maximum size of the switchboard is increased by the convection space 11, which causes an increase in the installation space. On the other hand, although the option of providing a light-shielding board only in a required part is also considered, since the appearance of a switchboard changes a lot, it ended up having to provide a light-shielding board on the whole switchboard surface after all. Moreover, in order to attach the space member 10, welding and hole processing are needed for the door 7 and the side plate 8, and when these installation is performed after installing a switchboard, there existed problems, such as construction becoming difficult.

  Furthermore, when the door light shielding plate 7A is attached, the front surface of the air supply opening is blocked by the door light shielding plate 7A even if the necessary air supply opening is provided for the forced ventilation type. There is also a drawback that only ventilation space can be secured and ventilation efficiency is lowered.

  As described above, it is difficult to efficiently suppress the temperature rise in the switchboard by the conventional heat removal method for the switchboard for outdoor use, and if the temperature in the switchboard reaches a temperature higher than the installation conditions of the internal devices, There has been a problem in that it causes a failure or a decrease in the life of the internal device, and also reduces the life of the ventilation fan and the like.

  The embodiment of the present invention has been made to solve the above-mentioned problems, and it is possible to prolong the life of the internal equipment and the ventilation fan of the outdoor switchboard, to improve the space efficiency and to reduce the manufacturing cost, and to adversely affect the external environment. It is an object of the present invention to provide a method for preventing the deterioration of the life of an outdoor switchboard which does not

In order to solve the above problems, the method for preventing the service life of the switchboard according to the present embodiment for reducing the life of the switchboard includes a switchboard main body installed outdoors and affected by a plurality of heat sources, and internal devices accommodated in the switchboard main body. provided near the ceiling of the interior of the switchboard body, the temperature inside該配board body a and the ventilating fan to start running, outdoor switchboard reduced life prevention method equipped with a predetermined temperature, the outer surface of the switchboard body By applying heat insulation paint to the interior of the switchboard main body, and in particular, reducing the temperature rise inside the roof, delaying the time for which the temperature inside the switchboard main body reaches the predetermined temperature and operating the ventilation fan reducing the time, in the internal equipment and the lifetime deterioration prevention method to that shop external switchboard prevent deterioration life of the exhaust fan, to further reduce the exhaust fan operating time The operation starting temperature of the exhaust fan is to higher than the predetermined temperature.

  According to the embodiment of the present invention, it is possible to extend the life of the internal equipment and the ventilation fan of the outdoor switchboard, to improve the space efficiency and reduce the manufacturing cost, and to prevent the external environment from adversely affecting the life of the outdoor switchboard. A fall prevention method can be provided.

(A) is a front view of the outdoor switchboard which concerns on embodiment, (b) is the side view. The graph which shows the change of the temperature in the board at the time of applying the heat insulation paint, and in the case of no application. The proof test result of the switchboard for outdoor concerning embodiment. The side view of the conventional outdoor switchboard provided with the ventilation fan. The side view of the conventional outdoor switchboard provided with the cooling device. (A) is a front view of the conventional outdoor switchboard provided with the light-shielding plate, (b) is a side view thereof, (c) is a YY cross-sectional view of (a). XX sectional drawing of Fig.6 (a). The graph which shows the relationship between the ambient temperature and the life of a ventilation fan.

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the method for preventing the decrease in life of an outdoor switchboard according to the present invention will be described below with reference to the drawings.
[Configuration of outdoor switchboard]
The structure of the outdoor switchboard which concerns on this embodiment is demonstrated using FIG. 1 (a), (b).

  1 (a) and 1 (b), 1 is a box-shaped switchboard main body, 2 is an air inlet, 3 is a roof, 4 is a ventilation fan, 5 is a ventilation fan housing box, and 6 is a temperature installed inside the switchboard main body 1 A sensor 7 is a door provided on the front and back of the switchboard body 1, and 8 is a side plate of the switchboard body 1. In addition, the internal apparatus installed in the switchboard main body 1 inside is abbreviate | omitted.

The air supply port 2 is provided in the lower part of the door 7, and the ventilation fan 4 is installed in the vicinity of a ceiling inside the switchboard main body 1, for example, in the upper surface of the roof 3. In this case, the ventilation fan 4 is housed in a ventilation fan housing box 5 having a waterproof function, and the bottom surface of the ventilation fan housing box 5 communicates with the inside of the switchboard main body 1. The ventilation fan 4 starts operation when the measured value of the temperature sensor 6 reaches a predetermined temperature, for example, 40.degree. C., and meets the installation conditions of the internal equipment.
The switchboard main body 1 is usually installed outdoors, and is used in an environment exposed to a plurality of heat sources such as solar heat, radiant heat, heat generation due to operation of internal devices, and the like.

  In the present embodiment, the heat insulating paint is applied to the outer surfaces of the ventilation fan housing box 5 and the roof 3 so that the ambient temperature of the installation location of the ventilation fan 4 can be reduced, and the life reduction of the ventilation fan 4 due to high temperature can be reduced.

  In addition, if it is assumed that the front of the switchboard main body 1 is installed southward when it is desired to obtain a further temperature reduction effect, the south side (front door surface) affected by solar radiation heat all day long, the solar radiation effect in the morning It is preferable to apply it to the east side (right side surface) and the west side (left side surface) affected by solar radiation in the afternoon.

In addition, it is necessary to consider the effects of solar radiation, such as being in the shadow of other structures at times of solar radiation influence, because there is no sense of discomfort even if the coating is different from the thermal insulation paint and the ordinary paint depending on the surface if the paint colors are combined. If there is not, the normal paint may be applied without applying the thermal insulation paint. As a result, the amount of the insulating paint used can be reduced, and the temperature reduction effect can be obtained with the minimum necessary cost.
As a heat insulation paint, the thing of a water-soluble ceramic type is suitable, for example.

[Verification test]
The result of having conducted a demonstration test using the outdoor switchboard which concerns on this embodiment is demonstrated below.
(Test conditions)
The switchboard main body (test body 1) to which the conventional heat insulation paint is not applied (test body 1), the switchboard main body (test body 2) coated with the heat insulation paint according to the embodiment only on the roof surface, the heat insulation paint according to the embodiment is applied to the entire surface Three types of switchboard main bodies (test body 3) were respectively installed on an outdoor concrete surface, and the temperature difference between the outside air temperature inside the one hundred leaf box installed in the vicinity and the center part in the board and the roof inside was measured.

  The test was conducted from July to September 2017. The measurement results from 9 am to 5 pm, which are considered to be largely affected by solar radiation, were averaged to verify the effect of the thermal insulation paint. In addition, since a measurement value is not performing the driving | operation of a ventilating fan in an internal apparatus in the non-energized state, it is a temperature rise value only by solar radiation heat and radiant heat.

The heat insulating paint was a ceramic water-soluble paint, and the coating amount was applied at a standard of 400 g / m ² . By applying the heat insulating paint, a ceramic layer is formed on the roof surface and the like, and by reflecting infrared rays of sunlight, the amount of heat energy entering the switchboard main body is reduced.

(Test results)
Next, test results will be described based on FIG.
While the temperature rise value of the inside of the roof of the test body 1 to which the heat insulation paint is not applied is 15.9 K, the heat insulation paint is applied to the ventilation fan housing box 5 and the roof 3 (only the roof surface) containing the ventilation fan 4 The temperature rise value inside the roof is 11.7 K in the test sample 2 that was performed. Therefore, the temperature rise of the difference 4.2 K can be reduced.

  Assuming here that the ambient temperature at which the switchboard body is installed is 35 ° C (the outside temperature inside the clover box), and the internal equipment operates and the temperature rise due to the heat generation is 10 K. By adding 25.9 K, which is the sum of 15.9 K and 10 K described above, to 35 ° C., the temperature becomes 60.9 ° C., and as shown in FIG.

  On the other hand, in the test body 2 in which the heat insulating paint is applied to the ventilation fan housing box 5 and the roof 3, the temperature is suppressed to 56.7 ° C even if 21.7K which is the sum of 11.7K and 10K mentioned above is added to 35 ° C. It is considered that the life of the ventilation fan 4 does not decrease.

  Moreover, the temperature rise value of the central part in the board also prevents the radiant heat from the roof surface, and the temperature rise value of the test body 2 is 5.9 K, but in the case of the test body 1 where the heat insulating paint is not applied The temperature rise value of the inner central part is 7.5 K, and the difference of 1.6 K can be reduced, which leads to the improvement of the installation environment of the internal equipment.

  As described above, by applying the heat insulating paint to the ventilation fan housing box 5 and the roof 3, it is possible to prevent the life reduction due to the temperature of the ventilation fan 4 and to improve the installation environment of the internal devices.

  Furthermore, in the case of the test body 3 in which the heat insulating paint is applied to the entire surface of the switchboard main body 1, the temperature rise value inside the roof as shown in FIG. And 7.9 K, and the temperature rise value in the central part of the board can be reduced by 3 K and 7.5 K and 4.5 K, respectively, and even larger than when applied to the ventilation fan storage box 5 and the roof 3 alone. It became clear that the temperature could be reduced.

  As described above, since the temperature reduction effect can be further enhanced by increasing the number of sites to which the heat insulating paint is applied, it is possible to achieve more effective solar radiation heat by selecting the position to which the heat insulating paint is applied according to the conditions of the installation location. It is possible to take measures against radiant heat.

In addition, since the thickness of the heat insulating coating is smaller than that using the light shielding plate, there is no increase in the installation space, and the door opening angle does not decrease.
Further, even when measures against solar heat and radiant heat are taken after installation of the switchboard, solar heat and radiant heat can be reduced by applying the heat insulating paint to the surface of the necessary part, so that the construction can be carried out relatively easily.

  Furthermore, the heat insulating paint is a water-soluble ceramic paint, does not use a solvent, and does not emit fluorocarbon gas, so that environmentally friendly measures can be realized. It can be realized at a lower cost than other means (cooling device and shading plate) by combining the heat insulating paint with the ventilation fan, and it is also advantageous in terms of running cost (energy consumption, maintenance of ventilation fan (replacement / repair) cost) .

[effect]
As described above, the heat insulating paint is applied to the whole surface of the ventilation fan housing box 5 and the roof 3 of the switchboard main body 1 or the switchboard main body 1 to suppress the infiltration of solar heat and radiation heat from the place where the paint is applied. And the temperature rise inside the switchboard main body 1 is reduced, and as a result, as shown in the graph of FIG. 2, the temperature in the panel decreases to 40.degree. C. at which the temperature sensor 6 turns on the ventilation fan 4. While the time to reach can be delayed, the time to reach the temperature at which the ventilating fan 4 can be turned off becomes faster, and the operating time of the ventilating fan 4 can be shortened. As a result, the ventilating fan 4 determined by the operating time as shown in the graph of FIG. Can extend the life of

In addition, even if the ventilation fan 4 breaks down, the heat radiation can be prevented from infiltrating into the panel by the effect of the heat insulating paint, so that the temperature rise can be suppressed, and the time to deviate from the recommended environment for installing the internal equipment It can be reduced.
In addition, by reducing solar radiation heat and radiation heat, the temperature inside the switchboard main body 1 can be increased, and the capacity of the internal device can be increased by the amount of the increase.

  Furthermore, by applying the heat insulating paint to the outer surface of the switchboard main body 1, the temperature rise inside the switchboard main body 1 is mitigated, so the temperature at which the ventilation fan 4 starts operating is higher than the predetermined temperature 40 ° C. By setting the temperature slightly higher, it is possible to further reduce the operating time of the ventilation fan 4.

  While the embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and the gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 ... Switchboard body, 2 ... Air supply port, 3 ... roof, 4 ... Ventilation fan, 5 ... Ventilation fan storage box, 6 ... temperature sensor, 7 ... door, 7A ... door light-shielding plate, 8 ... side plate, 8A ... side light-shielding plate , 9: cooling device, 10: spacing member, 11: convection space

Claims (4)

A switchboard body affected by several heat sources are installed outdoors, and an internal equipment contained therein該配board body, provided in the ceiling near the inside of the switchboard body, the temperature inside該配board body to a predetermined temperature A method for preventing the service life of the switchboard for outdoor use having a ventilation fan which starts operating when the heat insulation paint is applied to the outer surface of the switchboard body, and the temperature rise inside the switchboard body, in particular the temperature rise inside the roof by mitigating the with switchboard body internal temperature delays the time to reach the predetermined temperature reduces the operating time of the exhaust fan, the internal device and the ventilation fan shop you prevent deterioration lifespan external switchboard In the method of preventing the decrease in life ,
In order to further reduce the operation time of the ventilation fan, the operation start temperature of the ventilation fan is set higher than the predetermined temperature.   The method according to claim 1, wherein the heat insulating paint is applied only to the roof surface among the outer surfaces.   The method according to claim 1, wherein the heat insulating paint is applied to the entire outer surface of the switchboard body.   The method according to any one of claims 1 to 3, wherein the heat insulating paint is a ceramic paint.

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