JP2000103399A - Air conditioner for aircraft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner for an aircraft satisfying the air- conditioning conditions required under the entire operating conditions of the aircraft, capable of operation with the least fuel consumption, and reducing the weight thereof. SOLUTION: An evaporator 22 of a VCS 4 is incorporated in a recirculation line 19 for obtaining an air of an appropriate temperature by mixing the cold air obtained by an ACS 3 with the air of the recirculation line 19 extracted from a pressurized chamber 2 and returned again thereto for cooling the recirculation air, and duplicate ducts and fans are eliminated. When cooling is required from the starting time, quick cooling operation for supplying a large quantity of air is carried out only by the ACS3 until the room temperature reaches a given temperature arbitrarily decided, and after the temperature reaches the given temperature, the evaporator 22 of the VCS4 is incorporated in the recirculation line 19 for extracting the air inside the pressurized chamber 2 and returning it thereto for cooling the recirculation air, and the supply air quantity to the ACS3 is reduced to the quantity required for the ventilation for carrying out low fuel consumption operation.

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 which is suitably applied to an aircraft requiring a relatively large-capacity air conditioning (hereinafter referred to as "air conditioning") such as a transport aircraft and a passenger aircraft.

[0002]

2. Description of the Related Art In an airplane in which a human is boarded, a pressurized room such as a cockpit or a cabin (cabin), which is a space in which a human lives, is generally provided with an air conditioner (hereinafter referred to as an air conditioner) in order to perform air conditioning for enabling comfortable living. (Hereinafter referred to as an air conditioner). In an air conditioner of an aircraft, pressurization is performed together with ventilation, cooling and heating. For this reason, taking in outside air is indispensable. In order to take in such outside air, high-temperature and high-pressure air compressed by a compressor of a main engine or an auxiliary power unit is extracted and used as an air source. The extracted high-temperature and high-pressure air is cooled by outside air and guided to an expansion turbine that rotates at a high speed, adiabatically expanded to obtain cold air, and mixed with high-temperature air that bypasses the turbine to obtain conditioned air and obtain an air-conditioned room (guest room). An air cycle system (hereinafter ACS) that leads to a pressurized room that is air-conditioned and air-conditioned, such as
) Is the mainstream.

In recent years, the ACS employs a high-pressure water separating (HPWS) system as a dehumidifying mechanism and effectively dehumidifies the air. As a result, the dew point of the air source for air conditioning is lowered, and the temperature of the cold obtained by the ACS is reduced to 10%. It is below the freezing point of about ° F. As a result, the amount of bleed air required to obtain the required cooling capacity has been reduced, and fuel consumption by bleed air (hereinafter referred to as fuel efficiency) has been improved. AC
Since the cold air at the S outlet is too cold to be directly input to the pressurized chamber, a recirculation line for extracting the air having a higher temperature in the pressurized chamber, mixing the cold air with the cold air to form the appropriate temperature air, and inputting the same. Now available.

However, when air conditioning is performed using only the ACS, a large amount of bleed air is still required. On the other hand, in a ground-based air conditioner, refrigerant gas (for example, CFC alternative gas) is compressed by a compressor, becomes high-temperature and high-pressure gas, is led to a condenser, is cooled by exchanging heat with outside air, is mostly liquefied, and is led to an expansion valve. It is adiabatically expanded by the expansion valve, becomes a cold fluid (two-phase fluid of gas-liquid mixture), is led to the evaporator, cools the circulating air by the latent heat of vaporization of the liquid phase, absorbs the heat, vaporizes it, and returns to the compressor. The vapor cycle system (hereinafter referred to as VCS) is the mainstream.

[0005] In VCS, power needs to be supplied to a motor for driving a compressor in order to compress refrigerant gas. However, since energy efficiency is high, the required power is converted to fuel consumption in an aircraft. The required fuel is about one tenth compared to ACS. But V
In CS, a motor, a compressor, a condenser, and an evaporator are required. Conventionally, the mass of the motor increases, and it is impossible to mount it on an aircraft. Recently, however, turbine compressors with tens of thousands to hundreds of thousands of revolutions per minute have been developed to compress refrigerant gas.Furthermore, due to advances in high-frequency rotating high-frequency motors and drive power supply technology, and advances in refrigerant gas sealing technology, aircraft A small and lightweight VCS that can be mounted on a vehicle can be realized.

FIG. 7 schematically shows the configuration of such a conventional air conditioner for an aircraft, and FIG. 8 clarifies a more specific configuration. That is, the conventional aircraft air conditioner connects the engine compressor 51 and the pressurized chamber 52 via the air conditioner 50.
Consists of an ACS 53 and a VCS 54 independent of the ACS 53. The ACS 53 includes an air cycle machine (hereinafter referred to as ACM) 55 including a compressor 55B and a fan 55C disposed coaxially with the turbine 55A.
Bleed line 80 for introducing bleed air to the inlet of the compressor
A bootstrap circuit 81 connecting the outlet of the compressor 55B and the inlet of the turbine 55A;
An air supply line 83 for transferring air exiting from the outlet of 5A to the pressurized chamber 52; a dehumidifying mechanism 82 configured by using a part of the bootstrap circuit 81 and the air supply line 83; A recirculation line 69 for extracting a part of the air through a fan 64, and the air and air supply line 8 of the recirculation line 69.
A mixing chamber 63 for mixing with the cold air of No. 3;
It has a high-temperature air line 84 that branches high-temperature air from the bleed line 80 via a temperature control valve 66 and guides the high-temperature air to the mixing chamber 63, and a control mechanism 85 that maintains the temperature of the pressurized chamber comfortably and controls operation. Become.

The air supplied from the air conditioner 50 cools or heats the heat load in the pressurized chamber 52 and is discharged from the pressure control valve 75 to the outside of the machine. At this time, the pressure in the pressurized chamber 52 is controlled to a pre-programmed pressure according to the flight altitude. In the bleed line 80, A
An engine fan that flows through the duct 90 and bleed air to prevent the gas from flowing into the CS 53 and to allow the ACS 53 to operate properly and to allow the piping to the ACS 53 to be covered with a low melting point but lightweight aluminum alloy or the like. Precooler 5 which is a heat exchanger with the outside air led from 91
6, a pressure regulator 57 and a flow control valve 65 for ensuring constant pressure and constant flow bleed regardless of the operating state of the engine compressor 51, and high-temperature and high-pressure air flowing through the bleed line 80 from the outside air duct 86 to the fan 55C. And a primary heat exchanger 58 for cooling by heat exchange with the outside air taken in by the heat exchanger.

On the other hand, the VCS 54 includes a compressor 70 driven by a motor 70A and a condenser 71 as a heat exchanger.
And a fan 89 for guiding outside air, an outside air duct 87 and an expansion valve 8
8. It is composed of an evaporator 72 which is a heat exchanger.
Then, the compressor 70, the condenser 71, the expansion valve 8
8. The evaporator 72 is connected by a pipe so as to form a circulation path of the refrigerant gas. The evaporator 72 serves as a cooled air line and a fan 7 for guiding the air in the pressurized chamber 52.
3 is connected to the recirculation line 74.

A conventional air conditioner for an aircraft is as described above. First, the bleed air from the engine compressor 51 is regulated by the pressure regulator 57 upstream of the bleed line 80 and then 400 ° by the precooler 56.
F or less, the flow is controlled to a constant flow rate by the flow control valve 65, cooled by the outside air introduced by the fan 55C of the ACM 55 in the primary heat exchanger 58, and then inputted to the compressor 55B of the ACM 55 to be adiabatically compressed. . The air exiting the compressor 55B is passed through the secondary heat exchanger 59 to the fan 5
It is cooled by the outside air introduced by 5C and introduced into the dehumidifying mechanism 82. In the dehumidifying mechanism 82, after being further cooled by the reheater 60, it is input to the condenser 61 and
The water is condensed by being cooled by the cold air that has exited, and is input to the water separator 62, and the water is removed by the centrifugal force generated by the swirling flow generated by the air flow. The dehumidified air is heated by the reheater 60 and the turbine 55A of the ACM 55
Is input to The input air is adiabatically expanded by the turbine 55A, and the energy of the expansion drives the compressor 55B and the fan 55C which are arranged coaxially to become cold air. After passing through the condenser 61, the cold air passes from the pressurizing chamber 52 to the recirculation line 6 in the mixing chamber 63.
The air is mixed with air extracted by the fan 64 of No. 9 and becomes appropriate temperature air, and is introduced into the pressurized chamber 52 from the inlet of the pressurized chamber 52.

On the other hand, in the VCS 54, a gas serving as a refrigerant (for example, an alternative Freon gas) is adiabatically compressed by a compressor 70 driven by a motor 70A to become a high-temperature and high-pressure gas. Heat is exchanged with the introduced outside air to be cooled, and most of the liquid is liquefied, guided to the expansion valve 88, and adiabatically expanded to become a cold gas-liquid two-phase fluid. The gas-liquid two-phase fluid is extracted from the pressurized chamber 52 by the fan 73 by the evaporator 72, and the high-temperature air flowing through the recirculation line 74 is cooled by the latent heat of vaporization of the liquid phase to become a gas again. Return to the inlet of the compressor 70. In this way, the evaporator 72 of the VCS 54 is interposed in the recirculation line 74 of the pressurized chamber air, and operates the VCS 54 to share a part of the cooling load of the ACS 53.

The air conditioner 50 further includes a temperature control mechanism including a pressurized chamber temperature sensor 67, a duct temperature sensor 68, a temperature control valve 66, a controller 77, and a control panel 78. The controller 77 controls the opening of the temperature control valve 66 so that the temperature detected by the pressurized chamber temperature sensor 67 becomes the temperature set on the control panel 78. The amount of high-temperature air introduced into the mixing chamber 63 bypassing the ACM 55 is controlled in accordance with the degree of opening of the temperature control valve 66, so that the temperature of the pressurized chamber 52 becomes equal to the set temperature. At this time, the temperature of the air supplied to the pressurized chamber is monitored by the duct temperature sensor 68, so that extremely cool air or warm air is not supplied.

[0012]

The conventional air conditioner for an aircraft operates as described above. However, if air conditioning is performed only with the above-described ACS, the amount of fuel consumption is large in a state where the amount of air extracted from the compressor is constantly large. Become. On the other hand, in order to operate only with VCS having good energy efficiency, a large-capacity device is required, and an air source for ventilation and pressurization is separately required, which is not suitable as an air conditioner for aircraft. AC
When using S and VCS together, if they are installed independently, a duct and a fan are required separately. An object of the present invention is to provide an air conditioner for an aircraft that solves such a problem.

[0013]

SUMMARY OF THE INVENTION In order to solve the above problems, an air conditioner for an aircraft according to the present invention is provided with a recirculation system for extracting cold air obtained by ACS and air in a pressurized room and returning the air again. A VCS evaporator is incorporated in the recirculation line to mix the air with the line air to obtain the appropriate temperature air, so that the recirculated air can be cooled and redundant ducts and fans can be omitted. . Further, when cooling is required from the start, a rapid cooling operation in which a large amount of air is supplied only with the ACS until the room temperature reaches a predetermined constant temperature can be performed. VC is installed in a recirculation line that extracts indoor air and returns it again.
The evaporator of S is incorporated to cool the recirculated air, and the amount of air supplied to the ACS is reduced to the amount required for ventilation to enable fuel-efficient operation. .

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing a specific embodiment of an air conditioner for an aircraft provided first by the present invention, and FIG. 2 is a diagram conceptually showing the present invention. As shown in the figure, the aircraft air conditioner of this embodiment is one in which an engine compressor 1 and a pressurized chamber 2 are connected via an air conditioner 40. The ACS 3 is an ACM 5 including a compressor 5B and a fan 5C disposed coaxially with the turbine 5A.
And a bleed line 30 for introducing bleed air to the inlet of the compressor 5B, a bootstrap circuit 31 connecting the outlet of the compressor 5B and the inlet of the turbine 5A, and the cold air flowing out of the outlet of the turbine 5A to the pressurized chamber 2. An air supply line 33 to be transferred, a dehumidifying mechanism 32 configured using a part of the bootstrap circuit 31 and the air supply line 33,
A recirculation line 19 for extracting a part of the air in the pressurized chamber 2 through a fan 14, and a mixing chamber 13 for mixing the air in the recirculation line 19 and the cold air in the air supply line 33.
A high-temperature air line 34 that branches high-temperature air from the bleed line 30 through the temperature control valve 16 and guides the high-temperature air to the mixing chamber 13, and a control mechanism 35 that performs control and the like for maintaining the temperature of the pressurized chamber 2 comfortably. Do it.

The air supplied from the air conditioner 40 cools or heats the heat load in the pressurized chamber 2 and is discharged from the pressure control valve 25 to the outside of the machine. At this time, the pressure in the pressurized chamber 2 is controlled to a pre-programmed pressure according to the flight altitude. The bleed line 30
An engine fan that flows through the bleed air and the outside air duct 38 to prevent the gas from flowing into the S3 and to allow the ACS3 to operate properly, and to enable the piping toward the ACS3 to be covered with a low melting point but lightweight aluminum alloy or the like. 39
Pre-cooler 6, which is a heat exchanger with the outside air derived from
A pressure regulator 7 and a flow control valve 15 for ensuring constant pressure and constant flow bleed regardless of the operating state of the engine compressor 1, and its bleed line 30
And a primary heat exchanger 8 for exchanging heat between the high-temperature and high-pressure air flowing through the outside air and the outside air flowing through the outside air duct 36 for cooling.

On the other hand, the VCS 4 comprises a compressor 20 driven by a motor 20A and a condenser 21 as a heat exchanger.
And the outside air duct 37, the expansion valve 2
4. The evaporator 22 is a heat exchanger.
And, the compressor 20, the condenser 21, the expansion valve 2
4. The evaporator 22 is connected by a pipe so as to form a circulation path of the refrigerant gas.

In the above configuration, the operation will be described next. First, the bleed air from the engine compressor 1 is regulated by the pressure regulator 7 upstream of the bleed line 30 and then cooled to 400 ° F. or less by the precooler 6. The flow rate is made constant by the flow control valve 15, cooled by the outside air introduced by the fan 5C of the ACM 5 in the primary heat exchanger 8, and then input to the compressor 5B of the ACM 5,
Adiabatic compressed. The air leaving the compressor 5B is
In the secondary heat exchanger 9, the air is cooled by the outside air introduced by the fan 5 </ b> C and introduced into the dehumidifying mechanism 32. In the dehumidifying mechanism 32, after being further cooled by the reheater 10, the condenser 11
The moisture is condensed by being cooled by the cold air that has been input into the turbine 5A and exited from the turbine 5A, and the moisture is removed by the centrifugal force generated by the swirling flow generated by the flow of the air input to the water separator 12. The air after dehumidification is heated by the reheater 10 and AC
It is input to the M5 turbine 5A. The input air is
Adiabatic expansion is performed by the turbine 5A, and the energy of the expansion causes the turbine 5A to rotate at high speed, and drives the compressor 5B and the fan 5C that are coaxially arranged to produce cold air. After passing through the condenser 11, the cold air passes from the pressurizing chamber 2 to the fan 14 of the recirculation line 19 in the mixing chamber 13.
Is mixed with air that has passed through the evaporator 22 of the VCS 4 and becomes appropriate temperature air, and is introduced into the pressurized chamber 2 from the inlet of the pressurized chamber 2.

On the other hand, in the VCS 4, a gas serving as a refrigerant (for example, alternative Freon gas) is adiabatically compressed by the compressor 20 driven by the motor 20 A, turned into a high-temperature and high-pressure gas, guided to the condenser 21 and discharged from the outside air duct 37 by the fan 23 by the fan 23. Heat is exchanged with the introduced outside air and cooled, and most of the liquid is liquefied, guided to the expansion valve 24, and adiabatically expanded to form a cold gas-liquid two-phase fluid. The gas-liquid two-phase fluid is extracted from the pressurized chamber 2 by the fan 14 by the evaporator 22, and the high-temperature air flowing through the recirculation line 19 is cooled by the latent heat of vaporization of the liquid phase to become a gas again. Compressor 2
Return to entrance 0. Thus, the evaporator 22 of the VCS 4 is provided in the recirculation line 26 of the pressurized chamber air,
The operation of the CS 4 shares a part of cooling of the cooling load of the ACS 3.

The air conditioner 40 further includes a pressurized chamber temperature sensor 1
7, a temperature control mechanism including a duct temperature sensor 18, a temperature control valve 16, a controller 27, and a control panel 28 is included. The controller 27 controls the opening of the temperature control valve 16 so that the temperature detected by the pressurized chamber temperature sensor 17 becomes the temperature set on the control panel 28. The amount of the high-temperature air introduced into the mixing chamber 13 by bypassing the ACM 5 is controlled in accordance with the opening degree of the temperature control valve 16, and the temperature of the pressurized chamber 2 is set to the set temperature. At this time, the temperature of the air supplied to the pressurized chamber 2 is monitored by the duct temperature sensor 18 so that extremely cool air or warm air is not supplied.

Next, the aircraft air conditioner provided first by the present invention will be described with reference to FIG. 2 and FIG. In the air conditioner for an aircraft of the present invention, as shown in FIG.
Are interposed in a recirculation line of the pressurized chamber air for mixing with the cold air guided from the ACS3 air supply line.
FIG. 3 shows a conventional ACS when the pressurized room temperature is set to 80 ° F. and the same cooling capacity is realized for an air conditioner that provides the same cooling capacity of a 100-seater class aircraft.
53 and the cooling capacity of ACS3 of the present invention and conventional VCS
It shows that the cooling capacity of the VCS 54 is the same as that of the VCS 4 of the present invention, and shows the temperature and the flow rate of the air flowing through each part from A to E shown in FIGS.

That is, in the air conditioner for aircraft provided first according to the present invention in which the ACS 3 and the VCS 4 are provided side by side, the ACS 3
7 is the same as the conventional air conditioner in that the VCS 3 and the VCS 4 are installed side by side, and has the same cooling capacity as the conventional air conditioner by interposing the VCS 4 in the recirculation line on the ACS 3 side. Fan 73 in the conventional device shown in FIG.
And ducts 90 and 91 are not provided, so that the weight and the size are reduced.

Next, an air conditioner for an aircraft provided secondly by the present invention will be described. In the aircraft air conditioner, in the device shown in FIG. 1, when rapid cooling is required, such as when starting air conditioning while the aircraft is stopped on a summer ground, the controller 27 detects the temperature of the pressurized chamber 2, When the temperature is equal to or higher than a certain temperature (for example, 86 ° F.), the VCS 4 is stopped, and only the ACS 3 is operated to supply a large flow of cooling air (rapid cooling mode), and the constant temperature (for example, 86 ° F.).
° F), the amount of air supplied to the ACS3 is automatically reduced to the minimum required ventilation level (about 50% of the air required for normal cooling only with the ACS3), and the VC3
S4 is activated and VCS4 also functions so as to be used for cooling (low fuel consumption mode). The switching between the rapid cooling mode and the low fuel consumption mode can also be manually performed from the control panel. When the VCS 4 is operated from the start of cooling, the room temperature of the pressurized chamber 2 becomes 86 ° F. at the beginning of the operation.
It may be much higher and under such conditions VCS4
In order to guarantee the pressure resistance when the pressure of the refrigerant gas rises, a larger and heavier device than the VCS 4 which is always used at 86 ° F. or lower is required. Therefore, in the present invention, only the ACS 3 is operated up to a certain temperature (for example, 86 ° F.),
At 6 ° F. or less, the mode is switched to the low fuel consumption mode using the VCS 4 together.

The A, B, C, and E parts shown in FIG. 2 in the rapid cooling mode and the low fuel consumption mode when the air conditioner for aircraft provided secondly according to the present invention is applied to, for example, a 100-seater class aircraft. FIG. 4 shows the temperature and flow rate, the cooling capacity in each mode, and the fuel consumption. In addition,
The consumption of fuel required for 1 lb / min of bleed air from the engine compressor is 1.1 lb / hr, and the fuel required to obtain electric power for driving the VCS is about 1/10 of the case where the same cooling capacity is obtained by ACS. And As is clear from FIG. 4, the fuel consumption in the low fuel consumption mode depends on the AC in the rapid cooling mode.
This is about 52% of the case where only S3 is used, and can be operated almost in the low fuel consumption mode during normal operation, so that the fuel consumption required for air conditioning can be greatly improved. VC used together with ACS3
Since S4 is used only in the fuel-efficient mode, the required capacity is only about one-third the cooling capacity of the ACS3 in the fuel-efficient mode, and the size and weight can be reduced.

The specific configuration of each section is not limited to the illustrated example, and various modifications can be made without departing from the spirit of the present invention. In the above embodiment, AC
Although the air source in S3 is the bleed air from the engine compressor 1, the same operation can be obtained even if the bleed air is obtained from the compressor of the auxiliary power unit. Also, ACM
5 is a three-wheel type, and the dehumidifying mechanism 32 employs HPWS capable of lowering the dew point of the conditioned air.
Each system shown in FIGS. 5 and 6 may be applied to the present invention. FIG. 5 shows a two-wheel type ACM5 having a compressor 5B disposed coaxially with a turbine 5A and an HPW.
This is a combination of the S type dehumidifying mechanism 32.
The ejector 41 in the figure is used as a substitute for the fan 5C of the ACM 5, is composed of a group of nozzles, and discharges a part of the bleed air from the engine compressor 1 into the outside air duct 36 communicating with the outside air at a high speed. Thereby, the outside air is drawn in to create a necessary flow of cooling air. FIG.
1 uses a low pressure water separating (LPWS) system in which the water separator 12 is simply arranged at the outlet of the turbine 5A as the dehumidifying mechanism 32, and uses a two-wheel type ACM5 similar to FIG. .

[0025]

The air conditioner for aircraft provided first by the present invention is configured as described above, uses ACS and VCS together, and mixes VCS with cold air of ACS to produce conditioned air of appropriate temperature. By interposing the pressurized chamber air in a recirculation line for obtaining the same, a part of the fan and the duct can be eliminated as compared with a case where each is separately provided, so that the size and weight can be reduced. Furthermore, the air conditioner for aircraft provided secondly by the present invention takes advantage of the features of the ACS and the VCS, and in the rapid cooling mode, does not use the VCS, but rapidly cools only with the ACS, and uses the VCS in the low fuel consumption mode in combination. , VCS can be small and light, and can be operated with the amount of extracted air for the ACS significantly reduced, so that the fuel efficiency required for air conditioning can be greatly improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of an aircraft air conditioner according to the first aspect of the present invention.

FIG. 2 is a diagram showing a main configuration of an air conditioner for an aircraft according to the first aspect of the present invention.

FIG. 3 is a diagram for explaining a temperature, a flow rate, and the like of air flowing through each part in FIGS. 2 and 7 in comparison;

FIG. 4 is a diagram illustrating the temperature, flow rate, fuel consumption, and the like of air flowing through each part according to the operation mode of the aircraft air conditioner according to claim 2 of the present invention.

FIG. 5 is a diagram showing a modification of the present invention.

FIG. 6 is a diagram showing a modification of the present invention.

FIG. 7 is a diagram showing a main configuration of a conventional aircraft air conditioner.

FIG. 8 is a diagram showing a configuration of a conventional aircraft air conditioner.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Engine compressor 2 ... Pressurization room 3 ... Air cycle system (ACS) 4 ... Vapor cycle system (VCS) 5 ... Air cycle machine (ACM) 6 ... Precooler 7 ... Pressure regulator 8 ... Primary heat exchanger 9 ... Secondary heat exchanger 10 ... Reheater 11 ... Condenser 12 ... Water separator 13 ... Mixing chamber 14 ... Fan 15 ... Flow control valve 16 ... Temperature control valve 17 ... Pressure chamber temperature sensor 18 ... Duct temperature sensor 19 ... Recirculation line Reference Signs List 20 compressor 20A motor 21 condenser 22 evaporator 23 fan 24 expansion valve 25 pressure control valve 26 refrigerant circulation line 27 controller 28 control panel 30 bleed line 31 bootstrap circuit 32 dehumidifying mechanism 33 ... air supply line 34 ... hot air In 35: Control mechanism 36, 37, 3
8 ... Outside air duct 39 ... Engine fan 40 ... Air conditioning unit

Claims (2)

[Claims] An air cycle system in which air compressed by a compressor is adiabatically expanded to obtain cold air and used as a cooling source, and a refrigerant gas is compressed, cooled by a condenser and liquefied, and then adiabatically expanded freely. An air conditioner for aircraft, which includes a vapor cycle system that cools a fluid to be cooled by evaporating the latent heat of the cold fluid with an evaporator to obtain a cold fluid, and the cold air obtained by the air cycle system. And, in the recirculation line to extract the air in the air-conditioned room and the air of the recirculation line to return again to obtain the appropriate temperature air,
An air conditioner wherein the evaporator of the vapor cycle system is incorporated to cool recirculated air. 2. An air cycle system in which high-pressure air compressed by a compressor is adiabatically expanded to obtain cold air and used as a cooling source, and a refrigerant gas is compressed, cooled by a condenser and liquefied, and then thermally insulated. The air in the air-conditioned room is extracted in an air conditioner for aircraft, which is provided with a vapor cycle system that expands to obtain a cold fluid and cools the fluid to be cooled by the evaporator using the latent heat of vaporization of the cold fluid to perform air conditioning. Then, the evaporator of the vapor cycle system is incorporated into the recirculation line that returns again so that recirculated air can be cooled, and when rapid cooling is required, such as when cooling is required from the start, Until the room temperature of the air-conditioning room reaches a arbitrarily determined constant temperature, it operates only with the air cycle system. Reducing the supply air volume of the cooling system by the air cycle until the amount necessary for ventilation, air-conditioning apparatus is characterized in that so as to cool the recirculating air by the vapor cycle system.