JP4023006B2 - Air conditioner for aircraft - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an air conditioner for aircraft that is suitably applied to aircraft that require relatively large capacity air conditioning (hereinafter referred to as air conditioning), such as transport aircraft and passenger aircraft.
[0002]
[Prior art]
In an aircraft on which a human is boarded, an air conditioner (hereinafter referred to as an air conditioner) is generally used in a pressurized room such as a cockpit or a cabin (a cabin), which is a space in which a person lives, in order to perform air conditioning so that a comfortable living is possible. ).
In an air conditioner for an aircraft, pressurization is performed together with ventilation and air conditioning. For this reason, the intake of outside air is indispensable. In order to take in such outside air, high-temperature and high-pressure air compressed by the compressor of the main engine or auxiliary power unit is extracted and used as an air source. The extracted high-temperature and high-pressure air is cooled with outside air and led to an expansion turbine that rotates at high speed, adiabatically expanded to obtain cold air, mixed with high-temperature air that bypasses the turbine to obtain conditioned air, and an air-conditioned room (guest room) The mainstream is an air cycle system (hereinafter referred to as ACS) which is led to an air-conditioned space such as a cockpit or a pressurized space, hereinafter referred to as a pressurized chamber), and performs ventilation and pressure simultaneously with cooling and heating.
[0003]
Recently, ACS has adopted a high pressure water separating (HPWS) system as a dehumidifying mechanism, and as a result of effective dehumidification, the dew point of the air source of the air conditioning is lowered, and the cold temperature obtained by ACS is about 10 ° F. Has been below freezing. As a result, the amount of extraction required to obtain the required cooling capacity has been reduced, and fuel consumption by the extraction (hereinafter referred to as fuel efficiency) has been improved. Further, since the cold air at the ACS outlet is too cold to be directly input to the pressurized chamber, the recirculation is performed by extracting the air whose temperature has increased in the pressurized chamber and mixing it with the cold air to obtain the appropriate temperature. A line has been established.
[0004]
However, when air-conditioning is performed using only ACS, a large extraction amount is still necessary. On the other hand, in the air conditioner on the ground, refrigerant gas (for example, alternative chlorofluorocarbon 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 then led to an expansion valve, The expansion valve adiabatically expands freely, becomes a cold fluid (two-phase fluid of gas-liquid mixture), is led to the evaporator, cools the circulating air due to the latent heat of vaporization in the liquid phase, absorbs the heat, vaporizes, and returns to the compressor A vapor cycle system (hereinafter referred to as VCS) is the mainstream.
[0005]
In VCS, it is necessary to supply power to the motor that drives the compressor in order to compress the refrigerant gas. However, because of high energy efficiency, the fuel required for the same cooling capacity is required for the same cooling capacity in terms of fuel consumption in an aircraft. Is about one tenth compared to ACS.
However, in VCS, a motor, a compressor, a condenser, and an evaporator are required, and its mass has been increased so far, making it impossible to mount it on an aircraft. Recently, however, turbine compressors of several tens of thousands to 100,000 revolutions per minute have been developed for refrigerant gas compression, and aircrafts have been developed due to advances in high-frequency motors and high-speed motors that rotate at high speed and advances in refrigerant gas sealing technology. A small and lightweight VCS that can be mounted on a PC can be realized.
[0006]
FIG. 7 schematically shows the configuration of such a conventional aircraft air conditioner, and FIG. 8 clarifies a more specific configuration.
In other words, the conventional aircraft air conditioner is configured such that the engine compressor 51 and the pressurizing chamber 52 are connected via the air conditioning unit 50, and the air conditioning unit 50 includes the ACS 53 and the 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, an extraction line 80 for introducing extraction into the inlet of the compressor, an outlet of the compressor 55B, and the turbine The bootstrap circuit 81 that connects the inlet of the 55A, the supply line 83 that transfers the air that has exited from the outlet of the turbine 55A to the pressurized chamber 52, and a part of the bootstrap circuit 81 and the supply line 83 are used. A dehumidifying mechanism 82 configured as described above, a recirculation line 69 for extracting a part of the air in the pressurized chamber through the fan 64, and mixing for mixing the air in the recirculation line 69 and the cold air in the air supply line 83. High temperature air is branched from the chamber 63 and the bleed line 80 via the temperature control valve 66, and the mixing chamber A hot air line 84 leading to 3, comprises a control mechanism 85 for performing operation control such as to comfortably maintain the temperature of the pressurized chamber.
[0007]
Air supplied from the air conditioning unit 50 is discharged or discharged from the pressure control valve 75 after cooling or heating the heat load in the pressurizing chamber 52. At this time, the pressure in the pressurizing chamber 52 is controlled to a preprogrammed pressure according to the flight altitude.
The bleed line 80 prevents the bleed air from flowing into the ACS 53 in an abnormally high temperature state, allows the ACS 53 to operate properly, and covers the piping toward the ACS 53 with an aluminum alloy or the like that has a low melting point but is lightweight. In order to secure the bleed air with a constant pressure and a constant flow rate regardless of the operating state of the precooler 56 and the engine compressor 51, which are heat exchangers between the bleed air and the outside air led from the engine fan 91 flowing through the duct 90. And a primary heat exchanger 58 for cooling the high-temperature and high-pressure air flowing through the bleed line 80 by heat exchange with the outside air taken in by the fan 55C from the outside air duct 86. Has been.
[0008]
On the other hand, the VCS 54 includes a compressor 70 driven by a motor 70A, a condenser 71 that is a heat exchanger, a fan 89 that guides outside air, an outside air duct 87, an expansion valve 88, and an evaporator 72 that is a heat exchanger. The compressor 70, the condenser 71, the expansion valve 88, and the evaporator 72 are connected by a pipe line so as to form a refrigerant gas circulation path. The evaporator 72 is connected to a recirculation line 74 provided with a fan 73 for guiding the air in the pressurized chamber 52 as a cooled air line.
[0009]
The conventional air conditioner for aircraft is as described above. First, the air extracted from the engine compressor 51 is cooled to 400 ° F. or less by the precooler 56 after being adjusted by the pressure regulator 57 upstream of the air extraction line 80. The flow rate is adjusted to a constant flow rate by the flow rate 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 input to the compressor 55B of the ACM 55 for adiabatic compression. The air exiting the compressor 55B is cooled by the external air introduced by the fan 55C in the secondary heat exchanger 59 and introduced into the dehumidifying mechanism 82. In the dehumidifying mechanism 82, after further cooling by the reheater 60, the water is condensed by being cooled by the cold air that has been input to the condenser 61 and exited from the turbine 55A, and is input to the water separator 62, which is generated by the flow of air. The water is removed by the centrifugal force generated by the swirling flow. The dehumidified air is heated by the reheater 60 and input to the turbine 55A of the ACM 55. The input air is adiabatically expanded by the turbine 55A, and the compressor 55B and the fan 55C arranged coaxially are driven by the energy of the expansion to become cold air. After passing through the condenser 61, the cold air is mixed with the air extracted from the pressurizing chamber 52 by the fan 64 of the recirculation line 69 in the mixing chamber 63 to be appropriately heated air, and the pressurizing chamber is supplied from the inlet of the pressurizing chamber 52. 52.
[0010]
On the other hand, in the VCS 54, the refrigerant gas (for example, alternative chlorofluorocarbon gas) is adiabatically compressed by the compressor 70 driven by the motor 70 </ b> A, becomes a high-temperature high-pressure gas, is led to the condenser 71, and is introduced from the outside air duct 87 by the fan 89. It is cooled by exchanging heat with the outside air, and most of it is liquefied, and is led to the expansion valve 88 so as to be thermally insulated and freely expanded to become a cold gas-liquid two-phase fluid. This gas-liquid two-phase fluid is extracted by the evaporator 72 from the pressurizing chamber 52 by the fan 73 and the high-temperature air flowing through the recirculation line 74 is cooled by the latent heat of vaporization of the liquid phase portion to become gas again. Return to the inlet of the compressor 70. In this way, the evaporator 72 of the VCS 54 is interposed in the pressurized chamber air recirculation line 74, and the VCS 54 is operated to share a part of the cooling load of the ACS 53.
[0011]
The air conditioning unit 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 degree of the temperature control valve 66 so that the temperature detected by the pressurizing chamber temperature sensor 67 becomes the temperature set by the control panel 78. The amount of high-temperature air introduced into the mixing chamber 63 by bypassing the ACM 55 is controlled according to the opening degree of the temperature control valve 66, and the temperature of the pressurizing chamber 52 is set 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 extreme cold air or warm air is not supplied.
[0012]
[Problems to be solved by the invention]
A conventional aircraft air conditioner operates as described above. However, if air conditioning is performed using only the above-described ACS, the amount of fuel consumption increases in a state where the amount of extraction from the compressor is constantly large. On the other hand, in order to operate only with VCS with good energy efficiency, a large-capacity device is required, and an air source for ventilation and pressurization is required separately, which is not suitable as an air conditioner for aircraft.
Further, when ACS and VCS are used in combination, a duct and a fan are separately required if they are installed independently.
The present invention intends to provide an aircraft air conditioner that solves such problems.
[0013]
[Means for solving problems]
In order to solve the above-described problems, an aircraft air conditioner according to the present invention mixes cold air obtained by ACS with air in a recirculation line that extracts air in a pressurized chamber and returns again. It is characterized by incorporating a VCS evaporator in the recirculation line for obtaining the air so that the recirculated air can be cooled, and the redundant ducts and fans can be omitted.
In addition, when cooling is required from the start-up, rapid cooling operation can be performed in which a large amount of air is supplied only with ACS until the room temperature reaches a predetermined temperature. A VCS evaporator is installed in the recirculation line that extracts the indoor air and reintroduces it to cool the recirculated air, reducing the amount of air supplied to the ACS to the amount necessary for ventilation and reducing fuel consumption. It is characterized by being able to drive.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a diagram showing a specific embodiment of an aircraft air conditioner provided by the present invention first, and FIG. 2 is a diagram conceptually showing the present invention.
As shown in the figure, the aircraft air conditioner of this embodiment is such that the engine compressor 1 and the pressurizing chamber 2 are connected via an air conditioning unit 40. The ACS 3 includes an ACM 5 including a compressor 5B and a fan 5C arranged coaxially with the turbine 5A, a bleed line 30 for introducing bleed air to the inlet of the compressor 5B, and a boot connecting the outlet of the compressor 5B and the inlet of the turbine 5A. A strap circuit 31, an air supply line 33 for transferring cold air from the outlet of the turbine 5A to the pressurizing chamber 2, and a dehumidifying mechanism 32 configured by 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 the fan 14, a mixing chamber 13 for mixing the air in the recirculation line 19 and the cold air in the air supply line 33, and the extraction line The high-temperature air line 34 is branched from the high-temperature air 30 through the temperature control valve 16 and led to the mixing chamber 13, and the temperature of the pressurizing chamber 2 Comprising and a control mechanism 35 for controlling the like to comfortably maintain.
[0015]
The air supplied from the air conditioning unit 40 is discharged or discharged from the pressure control valve 25 after cooling or heating the heat load in the pressurizing chamber 2. At this time, the pressure in the pressurizing chamber 2 is controlled to a preprogrammed pressure according to the flight altitude.
The bleed line 30 prevents the bleed from flowing into the ACS 3 in an abnormally high temperature state, allows the ACS 3 to operate properly, and allows the piping toward the ACS 3 to be covered with a light-weight aluminum alloy having a low melting point. The precooler 6 is a heat exchanger between the bleed air and the outside air guided from the engine fan 39 flowing through the outside air duct 38, and the bleed air with a constant pressure and a constant flow rate is ensured regardless of the operating state of the engine compressor 1. And the primary heat exchanger 8 for cooling the high-temperature and high-pressure air flowing through the extraction line 30 with the outside air flowing through the outside air duct 36 for cooling.
[0016]
On the other hand, the VCS 4 includes a compressor 20 driven by a motor 20A, a condenser 21 that is a heat exchanger, a fan 23 that guides outside air, an outside air duct 37, an expansion valve 24, and an evaporator 22 that is a heat exchanger. The compressor 20, the condenser 21, the expansion valve 24, and the evaporator 22 are connected by a pipe line so as to form a refrigerant gas circulation path.
[0017]
In the above configuration, the operation will be described next. First, the bleed air from the engine compressor 1 is cooled to 400 ° F. or less by the precooler 6 after being regulated by the pressure regulator 7 upstream of the bleed line 30. The flow rate is made constant by the control valve 15, cooled by the outside air introduced by the fan 5 </ b> C of the ACM 5 in the primary heat exchanger 8, then input to the compressor 5 </ b> B of the ACM 5 and adiabatically compressed. The air leaving the compressor 5B is cooled by the external air introduced by the fan 5C in the secondary heat exchanger 9 and introduced into the dehumidifying mechanism 32. In the dehumidifying mechanism 32, after further cooling by the reheater 10, the moisture is condensed by being cooled by the cold air that is input to the condenser 11 and exits the turbine 5 </ b> A, and is input to the water separator 12 and generated by the flow of air. The water is removed by the centrifugal force generated by the swirling flow. The dehumidified air is heated by the reheater 10 and input to the turbine 5A of the ACM5. The input air is adiabatically expanded by the turbine 5A, and the turbine 5A rotates at high speed with the energy of the expansion, and the compressor 5B and the fan 5C arranged coaxially are driven to become cold air. After passing through the condenser 11, the cold air is extracted from the pressurizing chamber 2 by the fan 14 of the recirculation line 19 in the mixing chamber 13 and mixed with the air passing through the evaporator 22 of the VCS 4 to be appropriately heated air. Is introduced into the pressurizing chamber 2 from the inlet.
[0018]
On the other hand, in the VCS 4, a gas (for example, alternative chlorofluorocarbon gas) serving as a refrigerant is adiabatically compressed by the compressor 20 driven by the motor 20 </ b> A, becomes a high-temperature high-pressure gas, and is led to the condenser 21 and introduced from the outside air duct 37 by the fan 23. It is cooled by exchanging heat with the outside air, and most of it is liquefied, and is led to the expansion valve 24 so that it is adiabatic free expansion and becomes a cold gas-liquid two-phase fluid. This gas-liquid two-phase fluid is extracted by the evaporator 22 from the pressurizing chamber 2 by the fan 14 and the high-temperature air flowing through the recirculation line 19 is cooled by the latent heat of vaporization in the liquid phase portion to become gas again. Return to the inlet of the compressor 20. In this way, the evaporator 22 of the VCS 4 is interposed in the recirculation line 26 of the pressurized chamber air, and the cooling of the part of the cooling load of the ACS 3 is shared by the operation of the VCS 4.
[0019]
The air conditioning unit 40 further includes a temperature control mechanism including a pressurized chamber temperature sensor 17, a duct temperature sensor 18, a temperature control valve 16, a controller 27, and a control panel 28. The controller 27 controls the opening degree of the temperature control valve 16 so that the temperature detected by the pressurizing chamber temperature sensor 17 becomes the temperature set by the control panel 28. The amount of high-temperature air introduced into the mixing chamber 13 by bypassing the ACM 5 according to the opening degree of the temperature control valve 16 is controlled so that the temperature of the pressurizing chamber 2 becomes a set temperature. At this time, the temperature of the air supplied to the pressurizing chamber 2 is monitored by the duct temperature sensor 18 so that extreme cold air or warm air is not supplied.
[0020]
Next, the aircraft air conditioner provided first by the present invention will be described with reference to FIGS. In the aircraft air conditioner of the present invention, as shown in FIG. 2, the VCS 4 is interposed in a recirculation line of pressurized chamber air that mixes with cold air guided from the air supply line of the ACS 3. FIG. 3 shows the cooling of the conventional ACS 53 and the ACS 3 of the present invention when the pressure chamber temperature is set to 80 ° F. and the same cooling capacity is realized for an air conditioner that covers the same cooling capacity of a 100-seater class aircraft. The capacity and the cooling capacity of the conventional VCS 54 and the VCS 4 of the present invention are the same, and the temperature and flow rate of the air flowing through each part from A to E shown in FIGS. 2 and 7 are shown in comparison.
[0021]
In other words, the aircraft air conditioner provided in the first aspect of the present invention with ACS3 and VCS4 is the same as the conventional air conditioner in that ACS3 and VCS4 are provided, and VCS4 is used as a recirculation line on the ACS3 side. By interposing, it has the same cooling capacity as the conventional air conditioner, and is not provided with the fan 73 and the ducts 90 and 91 in the conventional device shown in FIG. It is.
[0022]
Next, an aircraft air conditioner second provided by the present invention will be described. In the aircraft air conditioner shown in FIG. 1, the controller 27 detects the temperature of the pressurizing chamber 2 when rapid cooling is required, such as when the air conditioner is started on the ground in the summer, etc. When the temperature is above a certain temperature (for example, 86 ° F.), the VCS 4 stops, operates only with ACS 3 and supplies a large amount of cooling air (rapid cooling mode), and reaches a certain temperature (for example, 86 ° F.). After that, the ACS3 air supply amount is automatically reduced to the minimum required ventilation amount (approximately 50% of the air required for normal cooling with only ACS3), and the VCS4 is activated to start the VCS4. Also functions in combination with cooling (low fuel consumption mode). Switching between the rapid cooling mode and the low fuel consumption mode can also be performed manually from the control panel. In addition, when the VCS4 is operated from the start of cooling, the room temperature of the pressurizing chamber 2 may be sufficiently higher than 86 ° F. at the initial stage of operation. When the VCS4 is operated under such conditions, the pressure of the refrigerant gas increases. In order to guarantee the breakdown voltage, a larger and heavier device than the VCS 4 that is always used at 86 ° F. or less is required. For this reason, in the present invention, only the ACS 3 is operated up to a certain temperature (for example, 86 ° F.), and the mode is switched to the low fuel consumption mode using the VCS 4 together at 86 ° F. or less.
[0023]
The temperature of each part of A, B, C, and E shown in FIG. 2 in the rapid cooling mode and the low fuel consumption mode when the aircraft air conditioner provided by the present invention is secondly applied to a 100-seater class aircraft, for example. The flow rate, cooling capacity in each mode, and fuel consumption are shown in FIG. Note that the amount of fuel consumed to extract 1 lb / min from the engine compressor is 1.1 lb / hr, and the fuel required to obtain power for driving the VCS is about 1 when the same cooling capacity is obtained with ACS. / 10. As is apparent from FIG. 4, the fuel consumption in the low fuel consumption mode is about 52% of that in the case of only the ACS3 in the rapid cooling mode, and it can be operated in the low fuel consumption mode during normal operation. Can greatly improve. Further, since the VCS 4 used in combination with the ACS 3 is used only in the low fuel consumption mode, the required capacity is as small as about 1/3 of the cooling capacity of the ACS 3 in the low fuel consumption mode, and the size and weight can be reduced.
[0024]
The specific configuration of each part 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, the air source of the ACS 3 is extracted from the engine compressor 1, but the same operation can be obtained even if the extracted air is obtained from the compressor of the auxiliary power unit. Further, although the 3-wheel type is used for the ACM 5 and the HPWS capable of lowering the dew point of the conditioned air is adopted for the dehumidifying mechanism 32, each system shown in FIGS. 5 to 6 may be applied to the present invention. FIG. 5 shows a combination of a two-wheel type ACM5 in which a compressor 5B is disposed coaxially with the turbine 5A and a HPWS type dehumidifying mechanism 32. The ejector 41 in the figure is used as an alternative to the fan 5C of the ACM 5 and is composed of a group of nozzles. A part of the bleed air from the engine compressor 1 is ejected at a high speed into the outside air duct 36 communicating with the outside air. This draws in the outside air and creates the necessary cooling air flow.
6 uses a low pressure water separating (LPWS) system in which the water separator 12 is disposed at the outlet of the turbine 5A as the dehumidifying mechanism 32, and uses a two-wheel type ACM 5 similar to FIG. It is.
[0025]
【The invention's effect】
The aircraft air conditioner provided by the present invention first is configured as described above, and uses both ACS and VCS, and pressurization for obtaining conditioned air of appropriate temperature by mixing VCS with cold air of ACS. By interposing it in the room air recirculation line, a part of the fan and duct can be eliminated as compared with the case where each is independently provided, and thus the size and weight can be reduced.
Furthermore, the aircraft air conditioner second provided by the present invention takes advantage of the features of ACS and VCS, and does not use VCS in the rapid cooling mode, but rapidly cools only by ACS, and in combination with VCS in the low fuel consumption mode. The VCS can be small and light, and can be operated with a greatly reduced amount of ACS extraction, 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 invention of claim 1 of the present invention;
FIG. 2 is a diagram showing a main configuration of an aircraft air conditioner according to the first aspect of the present invention.
FIG. 3 is a diagram illustrating the temperature, flow rate, and the like of air flowing through each part of FIGS. 2 and 7 for comparison.
FIG. 4 is a diagram illustrating the temperature, flow rate, fuel consumption, and the like of air flowing through each part in accordance with 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 ... Pressurizing chamber 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 rate Control valve 16 ... Temperature control valve 17 ... Pressure chamber temperature sensor 18 ... Duct temperature sensor 19 ... Recirculation line 20 ... Compressor 20A ... Motor 21 ... Capacitor 22 ... Evaporator 23 ... Fan 24 ... Expansion valve 25 ... Pressure control valve 26 ... Refrigerant circulation line 27 ... Controller 28 ... Control panel 30 ... Extraction line 31 ... Bootstrap circuit 32 ... Dehumidification mechanism 33 ... Air supply line 34 ... High temperature air line 35 ... Control mechanism 36, 37, 38 ... Outside air duct 39 ... Engine fan 40 ... Air conditioning unit

Claims (1)

High-pressure air compressed by the compressor is adiabatically expanded to obtain cold air and the cooling source is used as an air cycle system, and the refrigerant gas is compressed by a condenser, cooled by a condenser, liquefied, and then adiabatic free expansion is performed to generate a cold fluid In an air conditioner for an aircraft that is equipped with a vapor cycle system that cools the fluid to be cooled by the latent heat of vaporization of the cold fluid with an evaporator, and extracts the air in the air conditioning chamber and returns it again The evaporator of the vapor cycle system is incorporated in the recirculation line so that the recirculated air can be cooled. When rapid cooling is required such as when cooling is required from the start-up, the room temperature of the air-conditioned room is Is operated only by the air cycle system until the temperature reaches a predetermined temperature. Reducing the supply air volume of the cooling system by Le to an amount necessary for ventilation, air-conditioning apparatus is characterized in that so as to cool the recirculating air by the combined use of the vapor cycle system.

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