JP2002002596A - Air conditioner for aircraft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the amount of engine bleeding air even when requiring a large amount of ventilating air. SOLUTION: Engine bleeding air BA is inducted into a turbine T to drive an air cycle machine ACM, and the pressure of outside air is raised by using a compressor C driven by the turbine power so as to use for ventilating air. Therefore, the amount of the consumed engine bleeding air having high energy levels can be effectively reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner for an aircraft (hereinafter, abbreviated as "air conditioner") capable of supplying air for precompression to an airplane and simultaneously performing ventilation accompanied by cooling and heating in the airplane. Things.

[0002]

2. Description of the Related Art For example, an aircraft is generally provided with an air conditioner for supplying conditioned air of a suitable temperature and pressure to a precompression room such as a living room or an electronic equipment room. This air conditioner also has various functions such as temperature control, pressure control, dehumidification, oxygen supply to the preload chamber, and air leak from the housing. In order to fulfill these roles, intake of outside air is indispensable.

[0003] When taking in such outside air, it is not expected to obtain the pressure or oxygen amount necessary for preloading even if the outside air is taken in during high altitude flight. For this reason, an air conditioner has been established in which bleed air is always obtained from an engine in which a sufficient amount of outside air is present, the temperature of the bleed air is regulated and regulated, and the bleed air is supplied to the preload chamber as conditioned air.

As schematically shown in FIG. 3, an air cycle machine ACM, which plays a central role in this air conditioner, drives a turbine T by an engine bleed air BA, and transfers the turbine power to a compressor C which is coupled to a single shaft. Generally, the compressor C compresses the engine bleed air BA sent to the turbine T. In the figure, reference numeral 5 denotes a bootstrap circuit for sending the engine bleed air BA from the compressor C to the turbine T, and PHX, SHX
Is a heat exchanger.

[0005]

However, an airframe with many passengers, such as a passenger airplane, requires an extremely large amount of ventilation air. For this reason, relying on engine bleeding for everything
As a result of an increase in the amount of engine bleed and an increase in the penalty (fuel consumption) for the engine, there is a problem that the efficiency of the aircraft is greatly reduced.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is directed to an air cycle machine mainly comprising a turbine and a compressor connected in a single shaft, wherein engine bleed air is introduced into the turbine. By doing so, the air cycle machine can be driven, and outside air can be introduced into the compressor to increase the pressure for ventilation air.

[0007] According to such a configuration, the outside air can be compressed by the turbine power generated by the engine bleed and used as the ventilation air, so that the engine bleed amount can be reduced and the fuel penalty of the engine can be suppressed. it can.

The outside air is normally taken in from the ram air duct, but may be taken out by taking in air from the fan bleed.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. <First Embodiment> An air conditioner shown in FIG.
A precompression chamber 2 such as a living room or an electronic equipment room is connected via an air conditioner 3. The air conditioner 3 mainly includes an air cycle machine ACM including a compressor C and a turbine T. A bleed line 4 for introducing bleed air to the inlet C1 of the compressor C, a bootstrap circuit 5 for communicating the outlet C2 of the compressor C with the inlet T1 of the turbine T, and air exiting from the outlet T2 of the turbine T to the cycle machine ACM. Is connected to an air supply line 6 for transferring the pressure to the preload chamber 2.

A primary heat exchanger PHX is disposed in the bleed line 4 to cool the engine bleed air BA by exchanging heat with the ram air LA to prevent abnormal high-temperature bleed air from flowing into the air conditioning unit 3.

The air cycle machine ACM has a configuration in which the compressor C and the turbine T are connected by a single shaft with a shaft S, so that the power generated by the turbine T can be input to the compressor C.

The bootstrap circuit 5 includes a secondary heat exchanger SHX for efficiently cooling the air compressed and heated by the compressor C by heat exchange with the ram air LA. Is input to the turbine T to perform adiabatic expansion work in the turbine T.

The air supply line 6 connects between the outlet T2 of the turbine T and the preload chamber 2.

In this embodiment, the present embodiment branches off from between the outlet of the primary heat exchanger PHX and the inlet C1 of the compressor C and connects directly to the inlet T1 of the turbine T without passing through the bootstrap circuit 5. A bypass passage 7 is provided, and an inlet of the bypass passage 7 and an inlet C of the compressor C are provided.
Valves B and A are respectively provided upstream of
A ram air passage 8 having a valve C is connected to directly introduce outside air to the inlet C1 of the compressor C. Further, in the bootstrap circuit 5, a bypass passage 9 is provided which branches from between the outlet of the secondary heat exchanger SHX and the inlet T1 of the turbine T and is directly connected to the air supply line 6 without passing through the turbine T. Valves E and E are respectively provided at the inlet of the bypass passage 9 and upstream of the inlet T1 of the turbine T.
D is provided.

Next, the operation of the air conditioner will be described. In this air conditioner, a normal mode or a ram mode is selected by opening and closing the valves A to E. First, the normal mode will be described. In this mode, valves A and D are opened and valves B, C and E are closed. As a result, the temperature of the bleed air BA from the engine 1 is reduced by the primary heat exchanger PHX at the beginning of the bleed line 4, and the air is discharged from the compressor inlet C1 of the air cycle machine ACM to the compressor C.
And compressed. The air flowing out of the compressor outlet C2 is efficiently cooled by the secondary heat exchanger SHX, and is input to the turbine T from the turbine inlet T1. afterwards,
The air self-cooled by performing the adiabatic expansion work in the turbine T becomes an appropriate temperature and exits from the turbine outlet T2.
It is introduced into the preload chamber 2.

When ram air is taken in from above, the mode is switched to the ram mode. In this ram air mode, the valves A and D are closed and the valves B, C and E are opened. As a result, the engine bleed air BA is directly introduced into the turbine T via the bypass passage 7, and is used for driving the turbine T. Then, outside air is directly taken into the compressor C driven by the turbine power through the ram air passage 8, compressed by the compressor C, cooled by the secondary heat exchanger SHX, and flows through the bypass passage 9. ,
The air is merged with the engine bleed air BA coming out of the turbine T and becomes ventilation air at an appropriate temperature and an appropriate pressure and introduced into the pressurized chamber 2.

According to such a configuration, the engine bleed air B
Since the outside air can be compressed by the turbine power by A and the pressurized outside air can be used as ventilation air, the amount of engine bleed air can be reduced and the fuel penalty of the engine can be suppressed.

For example, an altitude of 35000 ft (10700
m) when cruising at M = 0.76, the outside air pressure is 3.4 psia (0.023 MPa) and the temperature is -54 ° C.
In the case of (STD Day), a case is considered in which the outside air is compressed to 12 psia (0.083 MPa), which is the pressurization in the cabin. Engine bleed is 45 psia
At (0.31 MPa), this system can be expected to reduce the amount of engine bleed air by about 27% compared to the conventional system shown in FIG. Further, even when the total efficiency in consideration of the weight penalty, the ram penalty, and the electric penalty is considered, the fuel consumption can be reduced to about 15%.

This embodiment is advantageous in terms of cost because an electric motor or the like is not used when taking in outside air, and it is necessary to secure higher reliability in the system in consideration of a power failure or the like. Can be. <Second Embodiment> An air conditioner shown in FIG. 2 is a modification of the air conditioner of the above embodiment, and is an air cycle machine ACM.
Is a three-wheel type, and a dehumidifying mechanism 10 is provided in a part of the bootstrap circuit 5. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

In this embodiment, both heat exchangers SHX, RH
The ram air LA to be supplied to X is taken in by a fan F1 arranged in a ram air duct, and the fan F1 is attached to a shaft S of the air cycle machine ACM. The air cycle machine in which the three impellers of the compressor C, the turbine T, and the fan F1 are mounted on the single shaft S is called a three-wheel type. This type is advantageous in that outside air can be actively taken in when parking the vehicle, particularly in Hot Day.

On the other hand, the dehumidifying mechanism 10 includes a reheater RH and a capacitor CON arranged in the bootstrap circuit 5.
D and a water separator WS. Capacitor C
The OND serves to efficiently cool the air having a dew point raised by being compressed by the compressor C in the bootstrap circuit 5 to condense the moisture, and the extremely low temperature condition of the air flowing out of the outlet T2 of the turbine T in the air supply line 6. The purpose of the present invention is also to exchange heat between the two airs for the purpose of solving the problem. The water separator WS has, for example, an internal structure capable of turning the air flowing into the inside into a swirling flow state. The water separator WS guides air condensed by the condenser COND to centrifuge only water having a high specific gravity by the swirling flow. It is capable of flowing out only air separated mainly by force and dehumidified. The reheater RH pre-cools the air upstream of the bootstrap circuit 5 toward the condenser COND and preheats the air downstream of the circuit 5 and exiting the water separator WS so as not to freeze at the outlet T2 of the turbine T. The purpose is to exchange heat between the two airs.

As described above, the dehumidifying mechanism 10 that raises the dew point in high-pressure air to condense water is called an HPWS (High Pressure Water Separator) system.

Even with the above configuration, switching between the normal mode and the ram air mode can be performed only by switching the valves A to E, basically as in the above embodiment. The engine bleed during high altitude flight is reduced, the penalty is kept low, and highly efficient cruising can be performed with high reliability.

The specific structure of each part is not limited to the illustrated embodiment, but can be variously modified without departing from the spirit of the present invention. For example, the outside air may be taken from the fan bleed of the engine instead of being taken in from the ram air duct. This fan bleed is only given a flow velocity to take in the outside air and compress it, and is a stage before the energy of compression and combustion is applied, so that the effect on the actual engine bleeding is low. It can be suppressed.

[0025]

As described above, according to the present invention,
Especially during high altitude cruise, engine bleed is introduced to drive the turbine, the power is transmitted to the compressor, and the external air taken in separately by this compressor is compressed. It is enough to secure enough intake for driving. For this reason, even in a passenger aircraft or the like that requires a large amount of ventilation air, it is possible to significantly reduce the penalty by reducing the amount of engine bleed air with a high energy level, and further include other parameters such as a ram penalty. Also, the total system efficiency can be effectively improved. In addition, since the air cycle machine is mechanically driven, the cost can be reduced and the reliability can be reliably improved as compared with the case where an electric system is employed.

[Brief description of the drawings]

FIG. 1 is a schematic system diagram showing a first embodiment of the present invention.

FIG. 2 is a schematic system diagram showing a second embodiment of the present invention.

FIG. 3 is a schematic system diagram showing a conventional system corresponding to FIG. 1;

[Explanation of symbols]

 ACM: Air cycle machine BA: Engine bleed C: Compressor T: Turbine

Continued on the front page (72) Inventor Seiji Uryu 1 Nishinokyo Kuwabaracho, Nakagyo-ku, Kyoto Co., Ltd. Shimadzu Corporation (72) Inventor Osamu Sato 1 Nishinokyo Kuwabaracho, Nakagyo-ku, Kyoto Co., Ltd. Shimadzu Corporation

Claims (1)

[Claims] 1. An air cycle machine mainly comprising a turbine and a compressor connected in a single shaft, wherein the air cycle machine is driven by introducing engine bleed air into the turbine, and the compressor is provided. An air conditioner for an aircraft, characterized in that it is configured so that outside air can be introduced into the air and pressure can be increased for ventilation air.