JPS5989499A - Electric device containing housing - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a semi-sealed type housing that prevents dew condensation inside a housing that houses electrical equipment installed outdoors in a power plant or a substation, thereby preventing an adverse effect on the electrical equipment. This invention relates to an electrical device storage case.

For electrical equipment storage enclosures installed outdoors in coastal areas or industrial areas, it is necessary to prevent salt and corrosive gases contained in the outside air from entering the enclosure and having a negative impact on the electrical equipment inside the enclosure. , the opening/closing part of the casing (for example, the door) is made with a backing structure to make the casing a semi-sealed structure, but the semi-sealed structure with the backing is not satisfactory against the intrusion of salt and dust. Although it shows a good protective effect, it has a poor protective effect against moisture permeation. For this reason,
During high-temperature periods such as summer and the rainy season, moisture drawn into the case through the backing may become supersaturated as the outside air cools at night, causing condensation inside the case, which can lead to corrosion of electrical equipment parts. , M may occur during the deterioration of the insulation properties of electrical equipment.

For this reason, as a method to prevent condensation inside the case of a closed can type, conventionally, a moisture-proofing agent such as zeolite or silica gel is used to remove moisture inside the case and lower the dew point inside the case, thereby preventing dew condensation. Another method was to prevent dew condensation by installing a space heater inside the housing to heat the inside air and maintain the temperature inside the housing above the dew point.

However, in the method of preventing condensation mentioned above, there is a limit to the moisture absorption capacity of the dehumidifier, so if the dehumidifier is considered a consumable item, the dehumidifier must be replaced frequently. There are maintenance problems and high costs. 'f TC When reusing a dehumidifier that has lost its dehumidifying ability due to moisture absorption, it is necessary to ventilate high-temperature dry air into the dehumidifier to expel the moisture in the dehumidifier. In order to produce this method, a large-capacity heater is required, and the dehumidifier and dehumidifier carrier material must be heat resistant, which requires large-scale equipment. The method of preventing dew condensation using a space heater alone uses the space heater to maintain the temperature inside the housing above the dew point without removing the moisture inside the housing. Unless the capacity is sufficiently large, there is a risk of condensation forming in cases where the housing is installed in a place with a large temperature difference between day and night.

The inventor of the present invention has conducted various investigations into the nodulation phenomenon that occurs within a sealed electrical device storage case, and as a result, 1. Conditions where dew condensation is likely to occur inside the housing are created during the hours from midnight until sunrise, when the outside temperature at night drops, the temperature inside the housing drops, and the moisture content inside the housing tends to become supersaturated, and during high temperature and high humidity in the summer. When there is a large temperature change inside and outside the case, such as when there is a sudden rain during the day and the outside temperature drops rapidly even during the day, the above two conditions cause most of the time for dew condensation inside the case. It was found that . Figure 1 shows the temperature and humidity inside the sealed electrical equipment storage case and the diurnal changes in the outside temperature during the summer using a conventional one-type space heater. They show contradictory curves, and as the outside temperature rises during the day, the temperature inside the housing also rises accordingly.

On the other hand, the humidity inside the housing decreases as the temperature inside the housing increases. However, after sunset, the situation is reversed; as the outside temperature falls, the humidity inside the housing increases, and if the humidity inside the housing during the day is high, it will be lower from midnight to dawn than during the previous cold period. The humidity inside the housing often reaches 95% or more, making it easy for dew to form.

In addition to the above-mentioned facts, this invention
! -It solves the drawbacks of sealed electrical equipment housings,
Its features are that all or part of the wall of the case installed outdoors has a double tank structure, the outer tank in contact with the outside air is made of a material with a high heat transfer coefficient, and the electrical equipment is housed. The inner tank is made of a material with a heat transfer coefficient of 1J-2, and a gap is provided between the outer tank side and the inner tank material, and the air inside the inner tank is circulated through the gap 2. Condensation is forcibly formed on the inner wall surface of the outer tank, and condensation is prevented from forming inside the inner tank where the electrical equipment is housed.

An embodiment of the present invention will be described below with reference to FIG.

In FIG. 2, (1) is an electrical component housing casing, and (2) is an outer tank of the electrical component housing casing (1), which is made of a material with a high heat transfer coefficient. In this example, a steel plate is used as the material for the outer tank (2), the surface in contact with the outside air is painted for outdoor use, and the inner surface is coated with a highly water-repellent coating (11). There is. (3) is an inner tank of the electrical equipment storage case (1), which is made of a material with a low heat transfer coefficient. In this example, this inner tank (
8) FRB is used as the material. (4) is a gap provided between the outer tank (2) and the inner tank (8). The ceiling (8a) of the inner tank (3) is sloped. (5) and (6) are ventilation holes drilled inside (81), (7) is a blower for circulating the air inside the electrical equipment storage case (1), and (8) is a blower for blower (7). A space heater installed nearby is used to heat the air that enters the electrical equipment storage area (1a) from the air gap (4) through the ventilation hole (6). (9) is the outer tank ( 2)
A drain tank is used to store moisture that has condensed on the inner wall of a drain tank, and its upper layer stores a non-volatile liquid (goods) (such as liquid paraffin) that has a lower specific gravity than water. (10) is a valve for releasing water stored in the drain tank (9). (18) is the door of the electrical equipment storage case (1).In order to prevent salt and dust from the outside air from entering the case, the backing (14) is used to create a closed structure inside the case. ing.

Next, the operation of the above embodiment will be explained. In addition to the above configuration, there is also a humidity sensor installed in the space of the electrical parts storage part in the housing, and a signal from this humidity sensor that activates the blower (7) when the humidity exceeds a preset value. A control device is attached that stops the blower (7) when the humidity drops below the specified humidity level. In this example, the blower (γ
The operating humidity of J shall be set to 80% or more and the stop humidity to 65% or less.

When the electrical device storage case (1) is heated by the sun during the day, the case is rapidly cooled down by sudden rain or other rain.
If the humidity inside the housing suddenly increases and exceeds the set humidity, or if the temperature inside the housing decreases as the outside temperature drops at night, and the humidity inside the housing rises and exceeds the set humidity, a control device (not shown) will Air blower (7) and this air blower (7
) The space heater (8) starts and stops in conjunction with the above. When the blower (7) operates in this manner, the air within the housing (1) circulates as follows: ventilation port (5) -> air gap (4) - ventilation port (6). 4) A material with a high heat transfer coefficient is used for the outer tank side diagonally, while a material with a low heat transfer coefficient is used for the inner tank material, so the outer tank wall surface follows the drop in outside temperature. However, the temperature change on the inner tank wall surface has a large time lag compared to the temperature change on the outer tank wall surface, so the temperature of the inner tank wall that is guided into the air gap (4) through the ventilation hole (5) is larger. The highly humid air in the tank (8) is cooled and dehumidified on the inner wall surface of the outer tank (2).

The inner wall of the outer tank is coated with a highly water-repellent coating phase (1
11, the moisture condensed on the inner wall of the outer tank falls and is stored in the drain tank (9). The drain tank (9) contains a non-volatile liquid (I21) that has a specific gravity lower than water, so the condensed water in the drain tank accumulates in the lower layer, causing the temperature inside the housing to rise again during the day. However, the water in the drain tank will not evaporate again.The dehumidified air will flow through the vent (6) provided at the bottom of the housing (1).
) and returns to the inner tank (8), but the air passage of the vent (6) is equipped with a space heater (7) as well as a blower (7).
8) is installed, and the dehumidified air is heated by a space heater (8) and returned to the inner tank (3) as low-humidity air. When the humidity in the inner tank (3) decreases to below a preset humidity, the air blower (7), which is controlled by a control device (not shown), operates in conjunction with the air blower (7). The space heater (8) will be in a stopped state. During high-temperature periods such as the persimmon rainy season, the humidity inside the housing may exceed the set value even during the day, but even at this time, the air inside the housing circulates according to the air path described above.

In this case, the effect of dehumidifying condensation on the outer tank wall cannot be expected, but if the outer wall is heated by solar heat, the air will be warmed by contact with the inner wall of the outer tank.
The relative humidity inside the housing will decrease @Also, since the blower (7) and space heater (8) are linked, the space heater (8) will warm the circulating air and the relative humidity inside the housing will decrease. If the temperature change inside and outside the case is small, there is no risk of condensation forming inside the case.

As described above, according to the present invention, all or a part of the can-closed electrical parts storage case is constructed as a two-tank structure, and when there is a large temperature difference between the inside and outside of the case, the temperature difference can be utilized. Condensation is dehumidified on the outer tank wall, and a humidity sensor is used to circulate the air inside the housing and operate the space heater only when the humidity inside the housing is high. Compared to a method that reduces the relative humidity inside the housing by 2 using only humidification using a space heater without removing moisture.
The space heater has a small capacity, is small, and consumes little electricity, making it highly economical.

[Brief explanation of drawings]

Fig. '1 is a diagram showing the temperature/humidity inside the sealed electrical device housing case and the diurnal changes in the outside temperature in a conventional one-type space heater, and Fig. 82 is a diagram showing the diurnal changes in the temperature/humidity inside the sealed electrical device housing case and the outside air temperature in the conventional one-type space heater. FIG. 3 is a vertical cross-sectional view of the storage case. In the figure, (1) is the electrical equipment housing, (2) is the outer tank, and (3)
1 is the inner tank, (4) is the gap, (51 (61 is the ventilation hole, (7
) is a blower, (8) is a space heater, (9) is a drain tank, and (11) is a water-repellent coating. Agent Makoto Kuzuno - Figure 1, Part 2vA Procedural amendment (spontaneous) 581220 Date of Showa Year/Monday Mr. Commissioner of the Japan Patent Office 1, Indication of case Patent application No. 191504 1987 2,
Title of the invention: Electrical equipment storage case 3, Representative of the person making the amendment: Jinhachi Katayama 5, Figure 46 subject to the amendment, Contents of the amendment Figure 1 of the drawing is corrected. Above Figure 1

Claims (1)

[Scope of Claims] (All or part of the wall surface of the 1-inch air-cooling device housing housing has a double tank structure with a gap in between, and the outer tank in contact with the outside air of this housing is on the side with a high heat transfer coefficient. In addition, the inner tank constituting the space in which the electrical equipment is housed is constructed with a side slant that has a small heat transfer coefficient, and the air in the electrical equipment housing space is circulated through the gap 2 between the inner and outer tanks. (2) The electrical device storage casing according to claim 1, wherein the inner wall surface of the outer tank is coated with a water-repellent coating. The electric device storage case according to claim 1 or 2, wherein a blower is installed in a ventilation hole opened in the 8J inner tank, and a space heater is provided near the blower. (4) The electric device storage case according to claim 8, wherein the blower and space heater are controlled by a signal from a humidity sensor provided in the electric device storage portion. (5) Between the inner and outer tanks. The electrical device storage case according to any one of claims 1 to 4, wherein a drain tank is provided at the bottom of the gap.