JP2748609B2 - Air conditioner for aircraft - Google Patents

Description

Description: BACKGROUND OF THE INVENTION (A) Field of Industrial Application The present invention relates to an aircraft, particularly to an air conditioner for an aircraft capable of flying at a supersonic speed even at a low altitude.

(B) Conventional technology In a conventional aircraft, in order to supply air for cooling passengers and electronic equipment, the bleed air from the engine is adiabatically compressed to a high temperature and high pressure, and this is exchanged with ram air as external air. It was cooled by a vessel, expanded adiabatically, adjusted to the optimum temperature and pressure, and then supplied.

 Hereinafter, this point will be specifically described with reference to FIG.

FIG. 2 shows the configuration of an air conditioning system for an aircraft. That is, in the flight engine (1), the outside air taken in by the compressor (1a) is compressed and further heated in the combustor (1b), and then the turbine (1c) is turned to generate a thrust force. A part of the air compressed by the compressor (1a) is taken out and used for air conditioning. This bleed air is exchanged by the ram air (2) and the heat exchanger (3) to be cooled. Next, it is adiabatically compressed by the radial compressor (4), further raised to a high pressure, and raised again to a high temperature. Then, it is cooled again by the heat exchanger (5) and is adiabatically expanded by the radial turbine (6) to obtain cooling air. Water droplets generated at this time are removed by the water separator (7). Further, the rotational force of the radial turbine (6) is used for the compression power of the radial compressor (4) via the shaft (8).
The bypass valve (9) is provided so that the temperature at the outlet of the radial turbine (6) is not unnecessarily lowered.
This is to control this amount when bypassing a part of the uncooled air.

(C) Problems to be Solved by the Invention In a conventional aircraft, when flying at a supersonic speed at a low altitude, the suction temperature of the engine is high, and the relative speed with the aircraft is high, so that the total temperature of the air is high, and The temperature is higher at the entrance. For this reason, the air compressed by the engine becomes hot, and a large amount of heat must be removed to cool it for temperature control. However,
The total temperature of the ram air used for cooling is high, and a large heat exchanger was required to sufficiently cool the bleed air. In addition, since the extraction temperature is high, the heat exchanger is made of a heat-resistant alloy such as stainless steel or a nickel-based alloy, so that it has been difficult to reduce the size and weight. In other words, in this system, when flying at low altitudes and supersonic velocities, the temperature of the bleed air rises to about 650 ° C, from which a large amount of heat is required to obtain air for breathing passengers and cooling electronic equipment. Need to be released.
However, at this time, the temperature of the ram air is also close to 300 ° C, and the weight of the heat exchanger for heat dissipation is about 1 in the currently flying aircraft (fighter).
In some cases, 26 kg and the second heat exchanger (5) weigh about 42 kg.

The present invention provides an air conditioner that solves such a conventional problem.

(D) Means for Solving the Problems The present invention uses air to supply air from bleed air when the flight speed of the aircraft increases and the bleed air temperature exceeds a specified value. It is designed to switch to use with circulating air. The circuit for generating the circulating air is provided with a CO ₂ removal device, a supply device from an O ₂ cylinder, and the like.

For the switching, there are provided means for detecting the temperature of the bleed air and outputting a signal when the temperature exceeds a specified value, and means for switching between the bleed circuit system and the circulation circuit system in response to a signal from this means.

(E) Function When the bleed air temperature exceeds the specified value, no bleed air is used for breathing air or electronic device cooling air, so that the load on the heat exchanger is eliminated.

(F) Embodiment The present invention will be described below with reference to the embodiment shown in FIG.

In FIG. 2, components having the same reference numerals as those in FIG. 1 have the same components or the same functions as those in FIG. 1, and a detailed description thereof will be omitted.

Now, it can be seen that a circuit for air circulation is added in the present invention. In these figures, the main components of the bleed circuit include a first heat exchanger (3), a second heat exchanger (5), and a turbine = compressor (4) (6). On the other hand, the circulation circuit has a CO ₂ adsorption column (14) for regenerating breathing air and a heat exchanger (17) for cooling circulating air.
Furthermore, a bleed temperature sensor (10) for realizing the operation according to the present invention, and a bleed cutoff valve (11) interlocked therewith.
There is a valve (12) for switching between bleed air and circulating air. In addition,
(20) and (21) show an outflow valve for discharging air in the in-machine pressurized region to the outside of the machine. (22) indicates a fan for circulating air, (23) indicates a fuel pump, and (24) indicates a cockpit.

In the above configuration, when the air temperature of the compression section (1a) exceeds a specified value (for example, 250 ° C.) by the temperature sensor (10), the supply of the bleed air is stopped by the shutoff valve (11), and at the same time, The circulating regeneration air is supplied by the switching valve (12). The circulating regenerated air that has been used for breathing once is adsorbent (13).
(For example, particles passing through a column (14) filled with particles such as solid amine and activated carbon), from which CO ₂ has been adsorbed and removed.

Further, a second device provided by the present invention will be described. As shown in the drawing, the air used for cooling the electronic device (15) exchanges heat with the fuel supplied from the fuel tank (16) to the engine (1) by the heat exchanger (17) to be cooled and regenerated. . During low-altitude supersonic flight, fuel is also supplied to the afterburner (1d), so fuel consumption has increased significantly compared to normal flight, and has sufficient heat dissipation capacity for air regeneration. ing. In addition, this heat exchanger (1
7) has a higher overall heat transfer coefficient than air-to-air heat exchange due to heat exchange between the regenerated air and liquid fuel.
A small one is sufficient. In addition, (18) is a respiratory mask, and (19) is an O ₂ cylinder for supplementing O ₂ lost by respiration. In addition, the O ₂ cylinder (19) and others can be shared with the system used to prevent the O ₂ partial pressure from decreasing during high altitude flight. In this case, among the switching valve (12), by using switching only the circulation side for a breath (12-a), reuse of O ₂ is made, O ₂
Consumption can be reduced.

In this embodiment, the adsorbent (13) is used. However, CO ₂ is removed by using a separation membrane or a chemical reaction, or CO ₂ is increased by increasing the O ₂ concentration.
_2. Reproduction may be performed by lowering the density relatively. The adsorbent (13) may include a device for regenerating the adsorbent when circulating air is not used. The heat exchanger (17) may be installed in the fuel tank (16) to exchange heat with the fuel in the tank. In this case, heat may be dissipated from the fuel tank wall via the fuselage. Further, it goes without saying that there are various implementation methods within a range not departing from the gist of the present invention, such as a design in which the circulating air is used for breathing and for cooling electronic equipment.

(G) Effects of the Invention Effects of the Present Invention In a conventional air conditioning system for a supersonic aircraft, the specifications of the equipment constituting the system were determined on the assumption that the aircraft would fly at a low altitude supersonic speed.

For example, at Sea level, M = 2 (0 above sea level, Mach number = 2), when the air temperature is 27 ° C, the total temperature of the ram air becomes 267 ° C. Become. For this reason, each device is designed with the maximum operating temperature under these conditions. Heat-resistant alloys such as stainless steel are used for the materials used, and the heat exchanger has a heat exchange area that can radiate heat to the high-temperature ram air. Have been. When the present invention is used, when flying at low altitude supersonic speed, the air inside the aircraft is provided by circulation, and high-temperature bleed air and high-temperature ram air are not used. Lightweight members such as composite materials can be used. Further, since there is no need to radiate heat to the high-temperature ram air, the heat radiation area of the heat exchanger can be reduced. As a result, the size and weight of the device can be reduced.

In a specific embodiment, the weight of the mounted device is reduced as follows.

Heat exchanger made of aluminum alloy or aluminum lithium alloy …… Approximately 40 kg reduced Valves made of aluminum alloy or aluminum lithium alloy …… Approximately 11 kg reduced Addition of shut-off valve (11) and switching valve (12) …… 5 kg Addition of heat exchanger (17) …… Approximately 3.5 kg increase Addition of adsorption column (14) and expiration regeneration circuit …… Approximately 4.5 kg increase If you subtract, you will realize a weight reduction of about 40 kg.

In addition to the weight reduction, the following effects can be obtained.

That is, since the bleeding is not performed during the flight at the supersonic speed, the thrust force is not reduced, so that the flight performance and the engine efficiency can be improved. In addition, when flying in a contaminated airspace such as radioactivity and chemicals, it can be shared with an expiratory circulation system that prevents damage from contaminated air by using circulating respiratory air. Further, since the ram air is not required when the circulating air circuit is activated, the air resistance of the airframe is reduced by closing the ram air intake at this time. Particularly in this case, since the flight is a supersonic flight, there is a remarkable effect in reducing the drag.

[Brief description of the drawings]

FIG. 1 shows an example of an aircraft air conditioning system according to the present invention, and FIG. 2 shows an example of a conventional aircraft air conditioning system. 1 ... engine, 2 ... ram, 3 ... first heat exchanger, 5
…… second heat exchanger, 4,6 …… turbine = compressor, 1
0: Bleed temperature sensor, 11: Shutoff valve, 12: Switching valve, 13: Adsorbent, 15: Electronic equipment, 16: Fuel tank, 17: Heat exchanger, 18: Respirator mask , 19 …… O ₂ cylinder

Claims (2)

(57) [Claims] An air conditioner for exchanging air extracted from a compressor of an engine with air outside the machine and then controlling the temperature and pressure in the aviation air by adiabatic expansion. A circulating air regenerating device that regenerates and reuses as an appropriate composition, a bleed air from the engine, a switching mechanism for switching any of the regenerated air and supplying the air to the aircraft, and a temperature of a bleed portion from the engine. A temperature detector for detecting and outputting a signal when the temperature exceeds a predetermined value,
An air conditioner for an aircraft, wherein the switching mechanism operates in response to an output signal from the temperature detector to stop the supply of bleed air and supply circulating air. 2. An air conditioner, which performs heat exchange of bleed air from a compressor of an engine with air outside the machine and then performs temperature control and pressure control in the aircraft by adiabatic expansion, from circulating air having a raised temperature to fuel. An air circulating circuit including a circulating air cooling device for releasing heat, a switching mechanism for switching between bleed air from the engine and circulating air from the circulating circuit and supplying the air to the aircraft, and detecting a temperature of a bleed portion from the engine to detect the temperature. A temperature detector for outputting a signal when the temperature exceeds a specified value, wherein the switching mechanism is operated by the output signal from the temperature detector to stop the supply of bleed air and supply the circulating air. An air conditioner for an aircraft, comprising: