RU2287455C2 - Aircraft bottle-free oxygen system - Google Patents

Abstract

FIELD: life support systems for crew of high-altitude aircraft.

SUBSTANCE: proposed bottle-free oxygen system for aircraft equipped with pressure cabin and ejection seats for crew members and pressurized suits has onboard oxygen-producing unit 1 including gas analyzer, pressure indicator and electronic control system, air preparation unit 2 to whose inlet compressed air is fed from engine compressor and its outlet is connected with onboard oxygen-producing unit 1; oxygen unit 4 is connected by its inlet with onboard oxygen-producing unit and is connected by its outlet with oxygen mask of crew member and ejection seat oxygen system. Connection of onboard oxygen-producing unit with oxygen unit is performed by means of outlet hose, check valve and gas supply sensor provided with two outlet pipe unions connected with oxygen unit by means of additional oxygen supply hoses.

EFFECT: enhanced reliability; ease in servicing.

3 cl, 1 dwg

Description

Technical field

The invention relates to life support systems for crews of high-altitude aircraft, and more particularly to oxygen systems, and can be used to reduce weight and improve their performance on highly maneuverable aircraft: fighters, attack aircraft, interceptors.

State of the art

The well-known "Method and device for supplying respiratory gas to the emergency oxygen system, in particular for aircraft" Company DAIMLER-BENZ AEROSPACE AIRBUS GMBH. The device includes a gas generator for producing oxygen-enriched gas from ambient air, air drawn from the engine, or from water. The mixing plant produces breathing gas supplied to the airborne network, and from it to the breathing masks (See US Patent No. 5809999, CL NKI 244 / 118.5, 1998).

A typical balloon-free oxygen system of an airplane is known, disclosed in the European patent of THE BOEING COMPANY, issued for “A device for warning a pilot about the failure of a life support system”, including an onboard oxygen production unit (BCCU) communicating via a breathing valve device with a breathing command regulator for supplying produced oxygen-rich breathing gas. The outlet of the respiratory command regulator is connected by a pipeline with masks for people (See EP 0364283, class MKI B 64 D 13/00, A 62 B 7/14, 1990).

Known systems are designed for emergency power passengers and are not adapted to provide pilots of high-speed high-altitude maneuverable aircraft.

Known oxygen systems designed to provide pilots of high-speed high-altitude maneuverable aircraft. The oxygen system of the Sukhoi Design Bureau aircraft company includes an on-board complex of an oxygen device, an armchair oxygen supply system, an on-board supply of gaseous oxygen (usually in oxygen cylinders) and oxygen masks. An on-board set of oxygen equipment is used as an emergency means of supplying crew oxygen with the process of descent to a safe height and briefly at heights to a practical ceiling when bailout with automatic switching to oxygen supply from the unit and oxygen equipment of the chair.In this case, oxygen cylinders are connected through oxygen devices to oxygen masks and to the chambers of the tension device of the high-altitude compensating suit by means of the oxygen valve, oxygen reducer, pressure switch, flow regulator, and the low-pressure cavity of the oxygen device is connected to the indicator housing (See RF patent No. 2207968, B 64 C 30/00, 2003).

The above system refers to the so-called balloon systems, the disadvantages of which are a large mass, a limited supply of oxygen.

Known balloon-free oxygen system of the aircraft - the life support system for the crew of the aircraft, disclosed in the European patent of the company NORMALAIR-GARRETT (HOLDINGS) LIMITED (Great Britain) EP 0321140, cl. MKI B 64 D 13/00, 1989

The system contains an onboard oxygen production unit (BKDU), the input of which is supplied with compressed air from the engine compressor, and the output is communicated through a breathing valve device with a breathing command regulator of a breathing machine (oxygen device - KP) to supply the produced oxygen-enriched breathing gas. In addition, breathing gas is also supplied to a sealed replacement container. As a rule, BKDU includes an air preparation device that purifies the air coming from the engine compressor.

The oxygen concentration in the produced gas is determined by the gas concentration sensor, which generates a signal for the electronic control system (EUS). The EMC generates signals for switching the control valve that controls the supply of produced gas to the breathing machine from the BKDS or from the spare container. The ESM also generates signals for the charging valve, which charges the spare container from the BKDS. The breathing command regulator of the breathing machine delivers the generated gas from the BKDS or from a spare container for mixing with the cabin air to produce a respiratory mixture that meets physiological requirements in all operating conditions, both in normal and emergency conditions, and, especially, to ensure long-term breathing at sea level from the spare container when the BKDS is not working. The outlet of the breathing machine using a pipeline is connected to the breathing mask of a crew member. In addition, the system includes an indication device.

The aforementioned system provides for mixing the gas obtained by the BCCU with the cabin air, which degrades its performance.

Known oxygen-free oxygen system of the aircraft company Carleton Life Support Systems Inc., installed on aircraft F-14, F-15, F-16, F / A-18, etc. The system includes an oxygen concentrator (analogue BKDU), in communication with the engine compressor and generating an oxygen-enriched breathing mixture, a cockpit valve device with a spare oxygen container, an oxygen regulator connected by a pipe to the crew member’s oxygen mask through a matching device, to which the oxygen catapultation system oxygen pipeline is also connected weakly configured as an oxygen bottle mounted on the side surface of the ejection seat.

The system is also equipped with an indication device that generates a warning signal about a decrease in pressure in the oxygen system (See the advertising description "F-16 OBOGS" by Carleton Life Support Systems Inc.).

In known systems, the supply of the respiratory gas mixture from the oxygen regulator to the crew oxygen mask is carried out through one pipeline, the passage area of which is selected from the condition of supplying the required amount of the respiratory mixture in all flight modes, which leads to the need to increase the diameter of the pipeline. This, in turn, leads to the fact that the stiffness of the pipeline, usually performed flexible, increases, the load on the crew member increases, his mobility is constrained. In addition, an oxygen cylinder mounted on the side surface of the ejection chair makes it difficult to eject due to the increase in the dimensions of the chair.

Disclosure of invention

The objective of the invention is to develop such a design of the oxygen system of the aircraft, which would improve its technical and operational characteristics: improving reliability, simplifying maintenance.

According to the invention, the goal is achieved in that in the oxygen-free oxygen system of the aircraft, equipped with a pressurized cabin with ejected seats for crew members and altitude-compensating suits, containing an on-board oxygen production unit (BKDU), including a gas analyzer, pressure signaling device and electronic control system (EUS); an air preparation device, the input of which is supplied with compressed air from the engine compressor, and the output is connected to the BKDU; oxygen device (KP), connected by its entrance to the BKDU, and the output - with an oxygen mask of a crew member; the ejection seat oxygen system (KSKK), the connection between the BKDU and the KP is made from the BKDU output hose, a check valve, a gas supply respiration sensor (DPGD), made with two output fittings connected by the main and additional oxygen supply hoses with the KP matching device.

In addition, the air preparation device is made in the form of an autonomous unit, the output of which contains two fittings, one of which is connected by a pipeline to the BKDU input, and the other is connected with an anti-overload device of a high-altitude compensating suit; the connection of the air preparation device with the anti-overload device of the high-altitude compensating suit is made using a pipeline connected to the input of a pressure switch made with two outlet fittings, one of which is connected to the pipeline of the anti-overload equipment, and the other through a synchronization pipeline, a pressure regulator, and an excess hose pressure is associated with an oxygen mask.

Moreover, the BKDU gas analyzer is connected to the pressurized cabin with the help of an equalizing line hose having low hydraulic resistance through the cockpit fitting, and the oxygen system of the ejection seat is installed in the profiled cushion of the ejection seat.

The implementation of the oxygen system with two hoses for supplying the respiratory mixture to the oxygen device allows to reduce pressure losses during the supply of the respiratory gas mixture with the minimum diameter of the hoses themselves, which ensures reliable supply of the respiratory mixture with the minimum values of compressed air supplied from the engines, which occur at the minimum engine operating conditions. This achieves the required flexibility of the hoses (due to the smaller diameter of the hoses), which simplifies the operation of the chair.

Description of the drawing

The invention is illustrated in the drawing, which shows a structural diagram of an oxygen system for a single-seat aircraft.

The implementation of the invention

In accordance with the invention, the oxygen-free oxygen system of an aircraft equipped with a pressurized cabin with ejected seats for crew members and high-altitude compensating suits is implemented as follows.

The system includes (see drawing):

- airborne oxygen production unit (BKDU) - 1;

- air preparation device (UVP) - 2;

- cabin fitting - 3;

- oxygen device (KP) - 4;

- pressure regulator (RD) - 5;

- The oxygen system of the ejection seat (KSKK) - 6;

- gas supply sensor for breathing (DPGD) - 7;

- oxygen supply hoses to KP - 8;

- hose overpressure - 9;

- hose DPGD - 10;

- automatic pressure (AD) - 11;

- check valve - 13;

- BKDU inlet hose - 14;

- BKDU outlet hose - 15;

- drain hose BKDU - 16;

- equalizer line barrier - 17;

- pipeline anti-overload equipment - 18;

- synchronizing pipeline - 19;

- discharge fitting - 20;

- pipeline - 21.

In addition, the system contains oxygen masks for crew members, an electrical control system for the units, an on-board display system, other connecting pipelines, fittings, fasteners, mounting devices and elements (not shown) that are necessary for operation.

On-board oxygen production unit (BKDU) - 1 is intended for the preparation of oxygen-enriched breathing mixture from outboard air taken from aircraft engine compressors. BKDU provides breathing of two crew members in all flight modes, including with overloads of up to 9 units, and with a decrease in the planning mode.

The principle of operation of BCCU is based on the use of special synthetic sorbents - zeolites, capable of absorbing nitrogen, moisture and harmful impurities from the compressed air passed through them and being purified from these components due to periodic connection with a more rarefied outboard atmosphere and due to periodic backflushing part of the produced gas mixture. Cartridges filled with sorbent - adsorbers are connected in turn with the compressed air supply line and with the environment. At certain points in the cycle, the produced gas mixture enriched with oxygen is taken from them.

The oxygen content in the produced respiratory mixture is controlled by a gas analyzer included in the BCDU using the method of measuring the partial pressure of oxygen using a solid electrolyte cell based on zirconium dioxide.

The overpressure of the produced respiratory mixture is controlled by the pressure signaling device included in the BKDU. The alarm device BKDU gives information about the failure if the overpressure is below the set level.

The electronic control unit BKDU provides the issuance of electrical commands in the form of periodic pulses of direct current to the electromagnets of the control valve block to control the process (not shown in the drawing).

The electronic unit receives the readings of the gas analyzer of the partial pressure of oxygen and the readings of the pressure signaling device of the respiratory gas mixture and issues signals to the on-board display system:

- "exit to the mode";

- "oxygen is the norm";

- "oxygen - failure";

- "the current value of the partial pressure of oxygen."

In order to distinguish between the ground and flight conditions by the electronic unit, a ground signal is issued from the bot system in the control system. The gas analyzer must measure the partial pressure of oxygen at the absolute (barometric) pressure in the measuring chamber of the sensor, corresponding to the air pressure in the cabin. Therefore, the gas analyzer is connected to the pressurized cabin through the cockpit fitting - 3 with the help of the equalization line hose - 17, which should have low hydraulic resistance. The static cavity of the overpressure alarm device (not shown in the drawing) is connected to the same line.

The air preparation device (UVP) - 2 is made in the form of an autonomous unit and is designed to purify the compressed air coming from the engine compressors and supplied to the onboard oxygen production unit and to the pressure control devices of the anti-overload device. UVP is equipped with one inlet - an inlet fitting connected to an air intake device from the compressor, and an outlet containing two nozzles, one of which is connected by a pipeline to the BKDU inlet, and the other is connected to an anti-overload device of a height-compensating suit. UVP consists of an electric condensate discharge valve and a filter (not shown in the drawing). The condensate drain valve is installed at the inlet of the air intake unit connected to the compressed air supply line from the engine. Two outputs of the condensate drain valve are connected respectively with a drainage pipe with a discharge fitting - 20 and a filter inlet. The electromechanism of the condensate discharge drive consists of an electric motor, a gearbox and a block of microswitches, which serves to automatically turn off the electric motor after turning the tap and to issue signals in the extreme positions of the output shaft. The condensate discharge valve, according to commands from the on-board automation, provides switching the compressed air supply from the drain pipe to the filter inlet and vice versa. The air entering the filter is cleaned of drip moisture and aerosols, including poisonous substances. Purified air through the filter outlet enters the inlet hose of the BKDU 14 and the pipeline of the anti-overload device (PPU) - 18 through a pressure switch (BP) - 11. Drip moisture is drained from the filter through the discharge fitting.

The drain hose BKDU - 16 is also connected to the discharge fitting - 20.

The oxygen device (KP) - 4 is made in the form of an easily removable unit mounted on the communications connector of the pilot's ejection seat and connected by a pipeline to the crew’s oxygen masks. KP - 4 is a regulator providing the supply of a respiratory gas mixture to the oxygen mask in proportion to the phases of respiration. KP - 4 also provides pressure in the oxygen mask, which compensates for the decrease in oxygen content in the inhaled medium during depressurization of the aircraft cabin, and in the chambers of high-altitude equipment - excess gas pressure at a high (stratospheric) height - more than 12 km. KP is made in the form of an easily removable block mounted on the communications connector of the pilot's ejection seat.

The connection between the BKDU and the gearbox is made of the BKDU outlet hose, a non-return valve, a gas supply respiration sensor (DPGD), connected in series with two output fittings connected by the main and additional oxygen supply hoses to the KP.

Thus, to KP - 4 from BKDU - 1, the respiratory gas mixture is supplied through the breathing gas supply sensor - 7 via two (primary and secondary) oxygen supply hoses - 8. Two hoses are used to provide their necessary flexibility with the required total flow area and minimal pressure loss.

In addition, KP - 4 is connected by a highway to the oxygen system of the ejection seat - 6. In this case, the oxygen supply hoses - 8 from the DPGD and the KSKK - 6 trunk are connected to the matching device KP - 4 (not shown in the drawing).

The gas supply sensor for breathing - 7 is designed to detect the presence of an oxygen-enriched air flow rate supplied from the airborne control system to high-altitude equipment for breathing of a member of the aircraft crew. DPGD includes a housing with an inlet and two outlet fittings, a jet oxygen flow generator, a piezoelectric pressure sensor and an electronic transducer. The jet generator generates oscillations of the jet, the frequency of which is proportional to the flow rate. The piezoelectric sensor converts the oscillations of the jet into the frequency of the generated electrical signal, and the electronic converter amplifies the electric signal from the piezoelectric sensor and converts the frequency to voltage (not shown in the drawing). The inlet nozzle DPGD - 7 is connected to the outlet hose BKDU - 15 through the hose DPGD - 10 and the non-return valve - 13. DPGD - 7 gives a signal proportional to the flow rate of the respiratory gas mixture to the airborne display system, which is a more reliable indicator for the pilot about the flow of the breathing mixture to KP and system performance. The non-return valve prevents the flow of oxygen from the BSCC towards the BCCU.

Automatic pressure - 11 is a valve mechanism with a control element that responds to changes in linear overload in flight. In proportion to the linear overload, the AD - 11 creates pressure in the chambers of the pilot's overload equipment. АД - 11 is made with an inlet fitting connected by an anti-overload equipment pipeline - 18 with a UVP - 2, and two outlet fittings connected respectively with a pilot anti-overload equipment with a flexible pipeline of anti-overload equipment - 18 and with a pressure regulator (RD) - 5 with a synchronization pipeline - 19. RD - 5, in turn, is connected with an oxygen mask with an overpressure hose - 9.

RD-5 supplies compressed air to the oxygen mask and is designed in such a way that it provides a predetermined pressure ratio in the oxygen mask and the chambers of the anti-overload device.

The oxygen system of the ejection seat (KSKK) - 6 includes an emergency oxygen source (compressed oxygen cylinder) and a locking and starting device and is mounted on an ejection seat (not shown in the drawing). Turning on the oxygen supply from the BSCC is performed automatically upon bailout or manually by the pilot in case of failure of the control system.

The system operates as follows.

The system is turned on after starting the auxiliary power plant of the aircraft with the oxygen system switch, the staples for turning on all systems (not shown in the drawing). After the system is turned on, the power supply of the BKDU - 1 is turned on, it is heated and adjusted. A signal “exit to mode” appears on the on-board display system screen.

After starting the main engines of the aircraft, air is discharged from the engines and auxiliary power unit. By a signal from the on-board control system, the UVP-2 switches from the drainage state to the compressed air supply mode to the BKDU-1 and to the AD-11 pressure machine through a filter that cleans the air of dust from aerosols and drip moisture. Drop moisture is discharged overboard, and the cleaned air enters the inlet of the BKDU - 1 and HELL - 11. Inside the BKDU, the air passes through the gearbox to the distribution valve block and then to the absorbers, where it is divided into oxygen-enriched breathing gas mixture (DHA) and the mixture, enriched with nitrogen. DGS enters through the DPGD - 7 and the KP - 4 oxygen device into the pilot's oxygen mask, and the mixture enriched with nitrogen is discharged into the unpressurized compartment of the aircraft.

The partial pressure of oxygen in the DGS is controlled by a gas analyzer included in the BKDU-1. Control of excess gas pressure at the BKDU outlet is carried out by a pressure switch. Information about the state of the gas generator from the gas analyzer and from the pressure signaling device enters the electronic control unit BKDU-1, which issues the following signals to the on-board display system:

- "exit to the mode" - for a certain time, after turning on the power BKDU - 1;

- "oxygen is the norm" - with the normalized partial pressure of oxygen in the DHA on the ground and in flight;

- "oxygen - failure" - when the partial oxygen pressure value leaves the normalized range for a specified period of time.

The signal on the presence of the supply of DGS to oxygen devices comes from the DPGD - 7 sensor. During normal operation of the "pulmonary automaton" of the oxygen device - 4 and the DGS flow through it, the DPGD - 7 gives a signal that changes in the phases of breathing, which is displayed by the on-board display system. When the pulmonary machine fails in the open position or when the continuous supply is turned on (using the handle of the oxygen device), the DPGD-7 generates a continuous signal of maximum level. In case of failure of the pulmonary automaton in the closed position or in the absence of the supply of DHS, a continuous signal of the minimum level is issued.

The oxygen system of the ejection seat KSKK-6 provides both manual and automatic inclusion from the onboard control system:

- in the case of depressurization of the cabin with a decrease in the barometric pressure to the level corresponding to the "height" in the cabin of more than 8 km and the signal "oxygen - failure" is received from the control panel;

- with a cabin height of more than 10 km.

Simultaneously with switching on the KSCK, the on-board automation issues an alarm oxygen signal to the display system.

When ejecting, the oxygen supply from the BSCC is automatically switched on using a mechanical device.

After the flight is completed and the engines are stopped, the on-board control system provides reverse switching of the UVP - 2 condensate discharge valve to the drainage position.

This embodiment of the onboard oxygen system allows to obtain the following advantages in comparison with existing balloon systems:

- there are no onboard oxygen cylinders and, accordingly, the system is not charged with oxygen before the flight;

- the flight duration is not limited by the oxygen supply in the system;

- reducing the weight, size and complexity of the operational maintenance of the system.

Claims (3)

1. The oxygen-free oxygen system of an aircraft equipped with a pressurized cabin with ejected seats for crew members and high-altitude-compensating suits, comprising an on-board oxygen production unit including a gas analyzer, pressure signaling device and an electronic control system; an air preparation device, the input of which is supplied with compressed air from the engine compressor, and the output is connected to an onboard oxygen production unit; an oxygen device connected by its inlet to the onboard oxygen production unit, and the outlet with an oxygen mask of a crew member; the ejection seat oxygen system and the electrical control system of the units, characterized in that the connection of the onboard oxygen production unit with the oxygen device is made up of series output hose of the onboard oxygen production unit, a check valve, a breathing gas supply sensor, made with two output fittings connected to the main and additional oxygen supply hoses with an oxygen device. 2. The oxygen-free oxygen system of the aircraft according to claim 1, characterized in that the air preparation device is made in the form of an autonomous unit, the outlet of which contains two fittings, one of which is connected by a pipeline to the input of the on-board oxygen production unit, and the other is connected with an anti-overload device of a height-compensating suit ; the connection of the air preparation device with the anti-overload device of the high-altitude compensating suit is made using a pipeline connected to the inlet of the pressure switch made with two outlet fittings, one of which is connected to the pipeline of the anti-overload equipment, and the other through a synchronization pipeline, pressure regulator, and overpressure hose connected in series associated with an oxygen mask. 3. The oxygen-free oxygen system of the aircraft according to claim 1, characterized in that the gas analyzer of the oxygen-free oxygen system of the aircraft is connected to the pressurized cabin using an equalizing line hose through the cockpit fitting.