RU2384477C2 - Ground deicing device - Google Patents

Abstract

FIELD: air transport.

SUBSTANCE: device contains thermal mat made of flexible woven electric heater closed by protective electric insulating material. Water repellent material and double layer of heat insulation and water repellent are placed at internal and external surfaces of protective electric insulating material. There is DC power supply source. Thermal mat is divided into number of sections, each having its heating area. Sections of flexible woven electric heater are divided into number of units with different power defined by preset length and width of flexible woven electric heater. Thermal mat is fixed at horizontal surface of aircraft by tapes or fast-type fixing.

EFFECT: enhancement of efficiency in snow and ice removal from lateral surfaces of the aircraft; ecologic cleanliness of maintenance with use of safety power supply at optimal regulation of power consumption and simplification of structure.

3 cl, 4 dwg

Description

The invention relates to aircraft, in particular to anti-icing systems of aircraft (LA) in the presence of conditions of ground icing, and can be applied in any field of power engineering.

Icing the aircraft while it is on the ground is different from icing in flight. If in flight ice is formed, as a rule, only on the frontal parts of the aircraft, then on the ground ice usually covers most of its surface: the entire upper part of the wings and stabilizers, as well as the surface of the fuselage. The main danger associated with ground icing of an aircraft is the development of premature disruption phenomena (at lower angles of attack) on icy wing surfaces and aircraft feathers, which threatens at the stage of take-off and climb with a violation of the stability and controllability characteristics of the aircraft, as well as the aircraft itself (see OK Trunov, 1995, Take-off safety under icing conditions, Moscow, GNIIGAR, p. 17).

The main means used in world practice to protect aircraft from ground icing are anti-icing liquids, which provide both the removal of ice, snow, hoarfrost, hoarfrost, and the prevention of their formation on the surface of the aircraft for some time. The following basic requirements apply to anti-icing fluids:

- high efficiency removal of all types of ground icing: hoarfrost, hard (crystalline) plaque, hoarfrost, ice;

- the ability to protect the surface of the aircraft from the formation of ice in the conditions of freezing precipitation (supercooled rain, wet snow, drizzle) for some time;

- the ability to completely discharge (blow off, drain) liquid from the wing surface during take-off aircraft (at speeds greater than 160 km / h);

- low energy consumption when pumping at low temperatures;

- safety when handling it (non-toxicity);

- have a minimal negative impact on the environment (since only 20-25% of the liquid is directly involved in the anti-icing process), since most of the liquid flows to the ground during the processing of the aircraft or is blown away from its surface by the wind. The liquid remaining on the aircraft surface is necessarily discharged during take-off and spreads along the runway and further in flight.

Type I anti-icing fluid does not require long-term protection of the aircraft from re-icing after the aircraft is doused - it must rise into the air in a matter of minutes, and when lifting, release the anti-icing liquid along with melted ice (snow, hoarfrost, etc.) to the ground. Type I deicing fluid is Newtonian.

Type II anti-icing fluids require longer-term aircraft protection, long-term resistance to supercooled rain, lower temperatures, etc. For this, highly thickened compositions with toxotropic properties and a non-Newtonian course are used.

However, the use of anti-icing fluids significantly violates the environmental situation in the airport area, and also requires constant replenishment of such fluids.

The most widely used are electric anti-icers with cyclic heating (see G.V. Komissarov, 1967, De-icing systems for aircraft, Moscow).

A device for protecting the aerodynamic surface of an aircraft against icing (see US patent No. 2627012 NKI 244-134, 1958), containing electric heating elements on the surface to be protected.

This technical solution has a high energy consumption with low efficiency of protection against icing.

Known electric heating de-icing device (see AC SU No. 335159 IPC B64D 15/12, 09/09/69), in which the heating element is made in the form of a thin layer of electrically conductive material deposited on a heated surface.

The disadvantage of the invention is the need for structural changes for each heated surface.

A device for removing ice from surfaces is known (see patent RU No. 2234781, IPC H02G 07/16, Н05В 06/00, B64D 15/00, 11/30/1999), which includes an electrode electrically isolated from the object, and a source direct current, for example, a battery connected to the object and the electrode, and an insulating material located between the object and the electrode is deposited on the object ferroelectric, lossy dielectric, ferromagnetic or semiconductor material. Electromagnetic energy causes the heat to be generated by the coating, resulting in melting ice and snow.

Known electric heating fabric (see patent RU No. 2182406, IPC Н05В 03/36, 05/10/2002), consisting of a number of non-conductive threads and at least two conductive tires. A pair of non-conductive threads connected to pairs of conductive wires connected with conductive resistive threads designed to supply uniform heat. At least two distribution buses are connected to the conductive buses for supplying electricity to the conductive buses. Each conductive bus and each distribution bus includes at least one low resistance filament for transmitting electricity.

The closest in technical essence and the achieved result is a protective thermal cover (see patent RU №2246188 IPC Н05К 07/20, dated December 28, 2001), containing a heating element implemented in the form of a flexible woven electric heater, on both sides of which protective screens are made, made from two layers, including heat-shielding fabric with various optical characteristics of the outer and inner sides and thermal insulation material.

The disadvantage of the invention is that functionally such a protective thermal cover provides thermal stabilization of the equipment from all sides and is a closed shell.

The technical result of the invention is to increase the efficiency of the removal of existing ice from the horizontal surfaces of the aircraft, as well as protection against ice formation in the conditions of freezing precipitation (supercooled rain, wet snow, drizzle) for some time, ensuring environmental cleanliness of the service, the possibility of using a safe power supply with optimized energy consumption and simplifying the design.

The technical result is achieved by the fact that a ground-based anti-icing device containing a one-sided thermomat is made of a flexible woven electric heater, closed on both sides with a protective insulating material, and on the inner and outer surfaces of which are placed water-repellent material and paired two layers of heat-protective and water-repellent material, and the source direct current.

Flexible woven electric heaters are divided into a number of elements of different capacities, determined by the required length and width of the flexible woven electric heater.

The thermomat is divided into a number of sections, each of which has its own heating zone.

The thermomat is fixed on horizontal surfaces of aircraft with tape mounts or fasteners.

The essence of the invention is the use of non-conductive resistive and low-resistance filaments, creating a woven material, having the necessary structural strength and predetermined temperature characteristics, covering, like a blanket, with a thermo-machine, the horizontal surfaces of the wings and aircraft stabilizers.

The invention allows to ensure the ecological cleanliness of aircraft maintenance at the home airport with the possibility of multiple use of the device with safe power supply.

In the process, flexible woven electric heaters that emit heat fluxes perform local (spot) heating of the aircraft’s horizontal surfaces, aimed at increasing the specific effects created by the unit of consumed electricity per unit area.

Simplification of the design of the ground de-icing device and automatic control of the temperature of the thermomat with an integrated display device is achieved due to the maximum unification of individual thermomats with their minimum number, different in size and power consumption.

Comparison of the proposed solution with well-known technical solutions shows that it has a new set of essential features that can successfully achieve the goal.

Figure 1 shows the wing profile with the placement of the ground de-icing device, figure 2 - the placement of the ground de-icing device on the horizontal surfaces of the aircraft, figure 3 - the disclosure system of the ground de-icing device on the airbus A-320 (US), figure 4 - control unit of the ground de-icing device.

The ground de-icing device comprises a thermomat 1 made of a flexible woven electric heater 2, closed on both sides with a protective electrical insulating material 3, and a direct current source 4, respectively, on the inner and outer surfaces of the protective electrical insulating materials 3, water-repellent material 5 and two paired layers of heat-protective 6 and water repellent material 5.

Flexible woven electric heaters 2 are divided into a number of elements of different capacities 7, determined by a given length and width of a flexible woven electric heater.

Thermomat 1 is divided into a number of sections 8, each of which has its own heating zone.

The thermostat 1 is fixed on the horizontal surfaces 9 and the empennage 10 of the aircraft with tape mounts 11 or fasteners of the fast 12 type.

The block diagram of the control automation of the ground de-icing device, Fig. 2, includes an electronic analysis and control unit 13, an indication unit 14, a control unit 15 and a switching unit 16, temperature sensors of the thermal sections 17 of the thermostat 1, wing temperature sensors under these sections 18, sensors environmental weather data 19, a power line 20 of each row of elements 7 of different power, a DC power supply 4, as well as a device operation monitor 21 and an aircraft ready to flight 22 monitor at the Flight Control Center.

The operation of the ground de-icing device is as follows.

Using a special movable mounting device, thermostats are mounted on the upper horizontal surfaces of the wings and the stabilizer.

After appropriate switching of the sensor and supply lines, the system is monitored according to indications on the monitor 21.

A command is given to turn on the heaters and the temperature of the heaters and the surface of the wings and the stabilizer are controlled.

Depending on weather conditions, according to meteorological data 19, the system operation mode is selected (in the presence of an ice crust or in the absence thereof).

When the temperature on the surface of the wing or stabilizer of the order of 10-13 ° C is reached, the power supply of the corresponding section is automatically turned off (on command from the control unit).

Optimization of the required power for each section and the possibility of supplying a separate power supply to the section can reduce the total energy consumption by 10-15%.

Depending on the type of aircraft used, the geometric dimensions of the thermomats are optimized in order to maximize their use and, accordingly, reduce the cost of solving the problem of anti-icing.

Let us consider the use of the thermomat 1 on the example of the A-320 (US) airbus, which has a wingspan of 43.9 m, and the area in terms of each wing is ~ 74.5 m ² and each stabilizer is 17.9 m ² .

Availability of ground icing conditions for aircraft:

"mode A" - the air temperature is close to 0 ° C, but there is no ice formation on the horizontal surfaces of the aircraft and the stabilizer;

"mode B" - over the entire horizontal surface of the wing and stabilizer there is an ice crust about 2 mm thick;

Electric energy consumption for heating the horizontal surface of aircraft wings and stabilizers up to + 10 ° С (from + 3 ° С to + 13 ° С) in “mode A” is about 10 kW for 1 hour of operation of the de-icing device.

Evaluation of the operation of the device in the presence of an ice crust with a thickness of about 2 mm and an ambient temperature of about 10 ° C showed that in 2 hours, with a total power consumption of about 95 kW, the ice crust melts and the surfaces of the wings and stabilizers are heated to 10-13 ° C.

The technical and economic effect of the invention is to increase the efficiency of removing ice and snow from horizontal surfaces and the tail of the aircraft in the presence of conditions of ground icing, ensuring environmental cleanliness of service with the possibility of using safe power supply with optimal power consumption, simplifying the design, reliability and durability of its performance.

Claims (3)

1. A ground de-icing device containing a thermomat made of a flexible woven electric heater, closed on both sides with a protective electrical insulating material, and a direct current source, characterized in that on the inner and outer surfaces of the protective electrical insulating materials there are respectively water-repellent material and paired two layers of heat-protective and water repellent material. 2. The ground de-icing device according to claim 1, characterized in that the thermomat is divided into a number of sections, each of which has its own heating zone. 3. The ground de-icing device according to claim 2, characterized in that the sections of the flexible woven electric heater are divided into a number of nodes of different capacities, determined by the specified length and width of the flexible woven electric heater.

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