KR102472478B1 - Anti-freezing system for belly tank of firefighting helicopter - Google Patents

Abstract

An objective of the present invention is to provide a system for preventing freezing of a belly tank, which can more efficiently extinguish forest fires even in the harsh winter season. The present invention relates to an anti-icing system of a belly tank for a firefighting helicopter. More particularly, the present invention relates to an anti-icing system of a belly tank, which comprises: a belly tank (10) mounted on a lower part of a fuselage of a firefighting helicopter; a water intake device (20) for sucking firefighting water into the belly tank (10); a door heating wire (30) installed on a bottom plate (11) of the belly tank (10); and a switch box (40) for controlling power supplied to the door heating wire (30).

Description

Anti-freezing system for belly tank of firefighting helicopter}

The present invention relates to an anti-icing system for a belly tank for a firefighting helicopter, and more specifically, a bellytank (10) mounted on the lower part of the fuselage of the firefighting helicopter, and water intake for sucking firefighting water into the bellytank (10). Consisting of a device 20, a door heating wire 30 installed on the bottom plate 11 of the belly tank 10, and a switch box 40 that controls power supplied to the door heating wire 30 It is about the anti-icing system of the belly tank.

When a forest fire breaks out in a mountainous area where it is difficult for fire trucks or firefighting personnel to enter, a firefighting helicopter (hereinafter referred to as a “fire helicopter”) is put in to extinguish the forest fire. These firefighting helicopters are divided into helicopters equipped with a belly tank and helicopters using a Bambi bucket according to a method of taking in and transporting firefighting water.

First, the belly tank is a large water tank installed in the lower part of the fuselage of the firefighting helicopter, and uses a water intake device to pump firefighting water from a water intake source. On the other hand, the Bambi bucket is a large water bucket that is tied to the lower end of the helicopter using a rope, and then directly pumps firefighting water using the water bucket and then moves as it is.

Therefore, it is known that the use of the belly tank compared to the Bambi bucket makes the flight of the fire helicopter safer, the water intake is quick and easy, and the fire fighting efficiency is excellent. Hereinafter, in the present invention, a firefighting helicopter means a helicopter equipped with a belly tank.

Attached Figure 1 is a reference to the structure of a firefighting helicopter (1) recorded in Utility Model Registration No. 20-0457773 (December 28, 2011), and a water tank (10) at the bottom of the helicopter body, that is, a belly tank and shows the structure in which the water intake device is installed.

The water intake device has two suction hoses 35, and a suction pump 30 and a strainer 40 respectively suspended from lower ends thereof. In addition, a bottom door (not shown in FIG. 1) is installed on the bottom plate of the water tank 10 so that firefighting water can be dropped from the air to the forest fire site.

Registered Utility Model No. 20-0457773 (December 28, 2011) Registered Patent No. 10-1244452 (Mar. 11, 2013) Registered Patent No. 10-2371671 (March 02, 2022)

In general, since large-scale forest fires occur mainly in the winter season, firefighting water is often frozen due to severe cold in the process of firefighting helicopters extinguishing forest fires. Attached Figure 2 is a photograph taken in a state where the area around the bottom door of the belly tank is actually frozen in a firefighting helicopter.

In this way, if the area around the bottom door of the belly tank is frozen due to severe cold while the firefighting helicopter is extinguishing the forest fire, a serious problem may occur in that the bottom door does not open well when the firefighting helicopter drops firefighting water to the forest fire site from the sky. .

In addition, if the area around the grid of the water intake device is frozen, it takes a lot of time to inhale fire-fighting water from the water intake source, or in severe cases, water intake may not be possible. may occur

So, in the past, there was a hassle of stopping the operation of the firefighting helicopter and frequently landing on the ground during forest fire extinguishing work to remove ice frozen around the bottom door of the belly tank or around the water intake pipe with a hammer or the like.

Accordingly, an object of the present invention is to prevent freezing of the bottom door or water intake device of the belly tank mounted on the fire helicopter, and as a result, to provide a system for preventing freezing of the belly tank, which enables forest fire extinguishing work to be performed more efficiently even in the cold winter season. is to provide

Hereinafter, in the present invention, independent names and reference numerals are assigned to each component regardless of FIG. 1.

The anti-icing system of the belly tank for fire-fighting helicopters according to the present invention is mounted on the lower end of the fuselage of the fire-fighting helicopter to accommodate fire-fighting water. a belly tank 10 having a bottom door 13 installed to open and close the openings 12; A water intake device (20) having a water intake pipe (21) for sucking firefighting water from a water intake source into the belly tank (10), and a pump case (22) for accommodating a water intake pump is installed at the lower end of the water intake pipe (21). Wow; It is attached to the bottom plate 11 of the belly tank 10 to surround the opening 12, and the straight portion 30a disposed side by side along both straight sides 12a of the opening 12, a door heating wire 30 formed of a curved portion 30b disposed roundly along both sides of the curved side 12b of the opening 12 and supplied with power from the power source of the firefighting helicopter; A switch box 40 installed in the cockpit of the firefighting helicopter to control power supplied to the door heating wire 30; It is characterized in that it is configured to include.

In addition, it is characterized in that a hydrophobic coating agent is applied to the outer surface of the bottom plate 11 of the belly tank 10.

In addition, the pump case 22 of the water intake device 20 is provided with a pump heating wire 50 receiving power from a power source of a firefighting helicopter and a plurality of heat conductors 51 extending from the pump heating wire 50, It is characterized by having

The system for preventing freezing of the belly tank according to the present invention has an effect of increasing firefighting efficiency by preventing freezing of the bottom door or water intake device of the belly tank even when a firefighting helicopter performs a forest fire extinguishing operation in the cold winter season.

1 is a view showing a conventional firefighting helicopter with a belly tank installed;
Figure 2 is a photograph to take a frozen state of the belly tank of the fire helicopter,
3 is a block diagram of an anti-icing system of a belly tank for a fire helicopter according to the present invention;
4 is a perspective view showing a belly tank 10 mounted on a KA-32 helicopter as an embodiment of the present invention;
5 is a perspective view showing the bottom plate 11 separated from the belly tank 10;
6 is a plan view showing the arrangement structure of the opening 12 penetrating the bottom plate 11 of the belly tank 10;
7 is a plan view showing a state in which the door heating wire 30 is installed on the bottom plate 11 of the belly tank 10;
8 is a view showing a state in which the door heating wire 30 is fixed to the bottom plate 11 of the belly tank 10 using a fixing clamp 32,
9 is a view illustrating a state in which the pump heating wire 50 and the heat conductor 51 are installed in the water intake device 20 of the fire helicopter;
10 is a view showing a state in which the wire passage pipe 15 is installed in the intake valve plate 14 of the belly tank 10;
11 is a photograph of a state in which an opening and closing test of a bottom door is performed for a valley tank (FAS-328) of a KA-32 helicopter.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. However, since the accompanying drawings illustrate preferred embodiments of the present invention, the scope of the present invention is not limited by these embodiments. In addition, even if the configuration is essential for carrying out the present invention, detailed descriptions of matters that are introduced in the prior art or can be easily implemented by a person skilled in the art from known technologies will be omitted.

As shown in FIG. 3, the anti-icing system of the belly tank for firefighting helicopters according to the present invention includes a bellytank 10 mounted on the lower end of the fuselage of the firefighting helicopter and suctioning firefighting water into the bellytank 10. Including a water intake device 20, a door heating wire 30 installed on the bottom plate 11 of the belly tank 10, and a switch box 40 that controls power supplied to the door heating wire 30 It consists of

For reference, FIG. 3 is a view showing a state in which the anti-icing system of the belly tank according to the present invention is installed in the 'KA-32 Helicopter' model manufactured by KAMOV and KumAPE of Russia.

First, the belly tank 10 accommodates firefighting water and drops it at a forest fire site, and is mounted on the lower end of the fuselage of a conventional firefighting helicopter. Attached FIG. 4 is a perspective view showing a belly tank (manufactured by DART Aerospace, USA) mounted on the KA-32 helicopter, and FIG. 5 is a perspective view showing the bottom plate 11 of the belly tank 10 separated.

The bottom plate 11 of the belly tank 10 is provided with a plurality of openings 12 through which firefighting water is dropped and a bottom door 13 opening and closing the openings 12, respectively. In addition, a door hinge 131 that rotatably supports the floor door 13, a cell crank 132 that opens and closes the floor door 13, a driving shaft 133, and a vertical diaphragm 134 that supports them, etc. has this installed. Attached Figure 6 is a plan view showing a state in which the bottom door 13 is removed from the bottom plate 11, showing a structure in which all four openings 12 penetrate in two lines.

The shape of the opening 12 installed in the bottom plate 11 is a narrow and long hole shape, each of two straight sides 12a are arranged side by side at regular intervals, and both ends of these straight sides 12a are curved. They are circularly connected to each other by side 12b. The number and shape of the bottom doors 13 naturally correspond to the number and shape of the openings 12 .

In addition, the water intake device 20 is a device for sucking firefighting water from a water intake source, for example, a lake, into the belly tank 10, and includes a water intake pipe 21 provided at the lower end of the belly tank 10 and a pump as shown in FIG. It has a case (22). The pump case 22 is made in the shape of a cylindrical sieve so that foreign substances do not flow in when firefighting water is sucked from a water intake source, and a water intake pump and an impeller (not shown in the drawing) are built in.

Next, as shown in FIG. 7, the door heating wire 30 is installed on the bottom plate 11 of the belly tank 10 to surround the opening 12, and the electric wire (W) from the power of the fire helicopter Power is supplied through The door heating wire 30 is specifically a straight portion 30a disposed alongside each other along both straight sides 12a of the opening 12, and both curved sides 12b of the opening 12 Arranged roundly It is preferable to arrange to have a curved portion (30b) to be.

According to a preferred embodiment of the present invention, the door heating wire 30 may use a PTC (positive temperature coefficient) heating wire. For reference, the PTC heating wire is an electric heating element using a thermistor, and has characteristics in that power consumption is low and heating temperature is controlled within a certain range by adjusting the amount of heat generated by itself according to a preset temperature.

The door heating wire 30 functions to heat the area around the opening 12 of the bottom plate 11 so that the bottom door 13 of the belly tank 10 does not freeze even in winter, and the heating sustain temperature is 60 to 90 It is preferable to use a PTC hot wire at °C. As such a PTC heating wire, for example, E&S TEC's 'FM60-2CR' product can be used, and the standard of this product is 18mm in width and 9.1mm in height, and has a flat cross-sectional shape.

According to the experimental results of the present inventors, when the PTC heating wire 'FM60-2CR' is used as the door heating wire 30, it was found that about 1,000 W of power is consumed. Therefore, it was confirmed that there was no significant effect on the power operation of the firefighting helicopter and no risk of fire due to high temperature.

Heat conductors 31a and 31b closely adhered to the bottom plate 11 of the belly tank 10 may be installed between both straight portions 30a and the curved portion 30b of the door heating wire 30, respectively. The heat conductors 31a and 31b function to transfer heat generated from the door heating wire 30 to the bottom plate 11, and a metal plate having excellent thermal conductivity, such as a copper metal plate, may be used.

As shown in FIG. 7, when the two openings 12 are arranged in a long line along the longitudinal direction and the door heating wire 30 is arranged to surround these two openings 12 together, the both openings 12 ), the door heating wire 30 is not disposed on the bottom plate 11 between them. Therefore, it is preferable to install a heat conductor 31a so that the heat of the door heating wire 30 is transferred between both straight portions 30a of the door heating wire 30 .

In addition, as described above, since the PTC heating wire has a width of 18 mm and a height of 9.1 mm and has a flat cross-sectional shape, when it is used as the door heating wire 30, the door heating wire 30 ) is not in close contact with the bottom plate 11 structurally, and a slightly lifted phenomenon occurs.

Therefore, in the curved part 30b, a problem in that the heat of the door heating wire 30 is not sufficiently transferred to the bottom plate 11 may occur. In order to solve this problem, heat conductors 31b are connected to both curved parts 30b of the door heating wire 30 at both ends of the straight part 30a and are in close contact with the bottom plate 11 of the belly tank 10, respectively. It is preferable to install

In the present invention, in order to install the door heating wire 30 and the heat conductors 31a and 31b on the bottom plate 11 of the belly tank 10, first secure a place to install the door heating wire 30 on the bottom plate 11 and evenly trimmed using sandpaper, etc., then washed and dried.

Subsequently, a thermal conductive sealant is applied to the prepared position, the door heating wire 30 is placed thereon, and then the door heating wire 30 is attached to the bottom plate 11 and the vertical diaphragm using the fixing clamp 32 as shown in FIG. 134).

Next, the heat conductors 31a and 31b are placed at necessary positions such as between the straight portions 30a on both sides of the heating wire 30 and the curved portion 30b, and are connected to the heating wire 30, respectively, and then fixed with a thermal conductive sealant. The thermal conductors 31a and 31b are adhered and fixed to the bottom plate 11 using clamps. At this time, if necessary, a suitable protective cover (not shown in the drawing) may be further installed on the heating wire 30 and the heat conductors 31a and 31b.

Finally, the switch box 40 controls the power supplied to the door heating wire 30 and is installed in the cockpit of the firefighting helicopter as shown in FIG. 3 . Therefore, the pilot operating the firefighting helicopter can determine whether or not to operate the door heating wire 30 according to the outside temperature and the state of the firefighting helicopter.

According to a preferred embodiment of the present invention, it is preferable that a hydrophobic coating agent is applied to the outer surface of the bottom plate 11 of the belly tank 10. The hydrophobic coating agent serves to expand the adhesion angle of water and is also referred to as a water repellent coating agent. The hydrophobic coating agent functions to prevent the freezing of the bottom door 13 as a result by allowing the fire-fighting water to flow straight down without remaining on the outer surface of the bottom plate 11 of the belly tank 10.

When a hydrophobic coating agent is applied to the outer surface of the bottom plate 11 of the belly tank 10 and the fire helicopter is operated, water droplets or ice fragments on the outer surface of the bottom plate 11 are very efficiently removed by the vibration of the fire helicopter. Removed.

Therefore, if the door heating wire 30 is installed inside the bottom plate 11 of the belly tank 10 and a hydrophobic coating agent is applied to the outer surface, a very synergistic effect can be obtained in achieving the object of the present invention.

As the hydrophobic coating agent, any one of commercially available hydrophobic coating agents may be selected and used within the scope of achieving the object of the present invention, but it is recommended to use a product having temperature durability of -50 to 200 ° C. desirable.

In addition, as shown in FIG. 9, the pump case 22 of the water intake device 20 includes a pump heating wire 50 supplied with power from a power source of a firefighting helicopter and a plurality of heat conductors extending from the pump heating wire 50. (51) may be included.

The pump heating wire 50 is preferably installed so as to surround an impeller of a water intake pump built in the pump case 22, and the heat conductor 51 crosses the pump case 22 in a direction crossing the pump heating wire 50. It is preferable to install a plurality of them on the inner wall of (22).

The pump heating wire 50 and the heat conductor 51 function to prevent the water intake device 20, particularly around the pump case 22, from being frozen by firefighting water in winter. The materials and specifications of the pump heating wire 50 and the heat conductor 51 may be the same as those of the door heating wire 30 and the heat conductors 31a and 31b.

In the present invention, a relay box 41 may be installed inside the fuselage of the fire helicopter to supply power to the switch box 40, the door heating wire 30, and the pump heating wire 50, respectively. In addition, as shown in FIG. 4, an intake valve plate 14 is installed on the ceiling plate of the belly tank 10, and a wire passage pipe 15 may be installed on the intake valve plate 14 as shown in FIG.

So, the wire (W) that supplies power from the relay box (41) to the door heating wire (30) and the pump heating wire (50) passes through the wire passage pipe (15) and then expands the inner space of the belly tank (10). It can be connected to the door heating wire 30 and the pump heating wire 50 across it. For reference, the intake valve pipe 14 is a passage through which external air is introduced so that a vacuum does not occur inside the belly tank 10 when the firefighting water stored in the belly tank 10 is dropped.

Hereinafter, in order to confirm the effect of the anti-icing system according to the present invention, the following experiment was conducted on a belly tank (model name: FAS-328) mounted on a KA-32 helicopter manufactured by Russian KAMOV and KumAPE.

[Test Example 1]

Separate one floor door from the valley tank (FAS-328), attach E&S TEC's PTC heating wire (continuous heating temperature: 60°C) to the inner surface of the floor door, and then set the floor door at an average temperature of -17°C. It was placed in a freezer at °C.

While supplying AC power of 220V to the PTC heating wire, the temperature change of the PTC heating wire and the temperature change of the outer surface of the floor door (ie, the opposite side of the PTC heating wire) were measured every 5 minutes for 1 hour, and the results are shown in [Table 1] included.

measurement time Temperature (°C) measurement time Temperature (°C) freezer heating wire outside door freezer heating wire outside door 0 minutes -18.6 -15.9 -18.9 30 minutes -17.0 30.3 16.2 5 minutes -17.8 30.3 -4.2 36 minutes -18.2 30.3 17.8 10 minutes -21.0 30.3 5.6 40 minutes -12.6 30.3 16.9 15 minutes -17.0 30.3 10.5 45 minutes -13.8 30.3 17.5 20 minutes -17.4 30.3 14.7 50 minutes -17.0 30.3 17.1 25 minutes -15.0 30.3 15.2 55 minutes -17.4 30.3 17.5

As shown in Table 1 above, at the beginning of the test, the temperature of the outer surface of the bottom door was about -18°C, which is almost similar to the temperature inside the freezer, but rose to about 10°C after 15 minutes and 17°C after 35 minutes. After reaching a certain temperature, it was found to maintain a similar temperature thereafter.

[Test Example 2]

First, the valley tank (FAS-328) was separated from the KA-32 helicopter, and E&S TEC's PTC heating wire (continuous heating temperature 60 °C) was attached around the opening 12 of the bottom plate 11. At this time, the PTC hot wire was disposed as shown in FIG. 7 but attached at a position spaced about 3 cm from the straight and curved sides of the opening.

Fill the inside of the valley tank with fire-fighting water about 1/4, put it in a freezer with an average temperature of -20°C, freeze it for 17 hours, and then open and close the floor door every 10 minutes while applying 220V AC current to the PTC heating wire. It was confirmed whether

Attached Figure 11 is a picture taken of installing a PTC heating wire in a separated valley tank (FAS-328) and checking whether the bottom door is opened or closed. As a result of the test, it was confirmed that all four floor doors were opened without difficulty after 40 minutes had elapsed.

(10) Belly Tank (11) Bottom Plate
(12,12a,12b) Opening (13) Bottom door
(131) Door hinge (132) Cell crank
(133) drive shaft (134) vertical diaphragm
(14) Intake valve plate (15) Cable passage
(20) Water intake device (21) Water intake pipe
(22) Pump case (30, 30a, 30b) door heating wire
(31a, 31b) Thermal conductor (32) Fixed clamp
(40) switch box (41) relay box
(50) Pump heating wire (51) Heat conductor
(W) wires

Claims (5)

It is mounted on the lower part of the fuselage of the firefighting helicopter to accommodate firefighting water, and a plurality of openings 12 for dropping firefighting water and a bottom door 13 for opening and closing the openings 12 are installed on the bottom plate 11. a belly tank 10;
A water intake device (20) having a water intake pipe (21) for sucking firefighting water from a water intake source into the belly tank (10), and a pump case (22) for accommodating a water intake pump is installed at the lower end of the water intake pipe (21). Wow;
It is attached to the bottom plate 11 of the belly tank 10 to surround the opening 12, and the straight portion 30a disposed side by side along both straight sides 12a of the opening 12, A door heating wire 30 including a curved portion 30b disposed roundly along both sides of the curved side 12b of the opening 12 and receiving power from the power of the firefighting helicopter;
a switch box 40 installed in the cockpit of the firefighting helicopter to control power supplied to the door heating wire 30;
a pump heating wire 50 installed in the pump case 22 to surround the water intake pump of the water intake device 20 and receiving power from a power source of the firefighting helicopter; including,
The door heating wire 30 and the pump heating wire 50 each have a heating sustain temperature of 60 to 90 ° C and are made of a PTC heating wire (positive temperature coefficient) having a flat cross-sectional shape,
Between the openings 12 of the belly tank 10 where the door heating wire 30 is not disposed, a heat conductor 31a connected to the middle of both straight parts 30a is installed, and the door heating wire 30 Heat conductors 31b connected at both ends of the straight portion 30a and in close contact with the bottom plate 11 are installed on both curved portions 30b floating on the bottom plate 11 of the belly tank 10,
A plurality of heat conductors 51 extending in a direction crossing the pump heating wire 50 are installed on the inner wall of the pump case 22 of the water intake device 20,
Characterized in that the intake valve plate 14 of the belly tank 10 is provided with a wire passage pipe 15 through which the wire W connected from the power source of the fire helicopter to the door heating wire 30 passes, the fire helicopter Anti-icing system for belly tank.
The system of claim 1, wherein a hydrophobic coating agent is applied to the outer surface of the bottom plate (11) of the belly tank (10).
delete The belly tank for firefighting helicopters according to claim 1, characterized in that the power supplied from the firefighting helicopter is supplied to the door heating wire (30) and the switch box (40) through a relay box (41) installed inside the fuselage. Anti-icing system. delete

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