JP2737281B2 - Air regeneration equipment for aircraft - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aircraft air regenerating apparatus for regenerating breathing air discharged by a passenger and supplying the regenerated air to the passenger again.

[Prior Art] Atmospheric O ₂ partial pressure decreases with altitude. Therefore, in order to supply O ₂ required for respiration to continue the aircraft passenger, it is necessary to appropriate means. In general, a small high-performance aircraft is provided with an enrichment unit for enriching engine bleed air with O ₂ , and a commercial aircraft is also equipped with equipment such as an O ₂ cylinder.

However, none of these facilities, the sole purpose of supplying the O ₂ exclusively passenger nor take measures any way for passenger discharged air. For this reason, the air discharged by the occupant is discarded randomly, together with the large amount of O ₂ remaining in it, and as a result, it is necessary to supply more O ₂ than necessary in the O ₂ enrichment section and O ₂ cylinder There was an inconvenience.

Therefore, in order to solve these inconveniences, the present inventors have proposed an air regenerating apparatus having the following configuration as described above. That is, as shown in FIG. 3, this is reduced to at least O ₂ by a circulation system 101 for circulating the air inside the machine with respect to the cabin b and the like, and a separation membrane 102a provided in the circulation system 101 and provided internally. Separator 102 that functions to selectively separate a larger amount of CO ₂ from high-pressure side 102 _H to low-pressure side 102 _L
And the separated CO ₂ connected to the low-pressure side 102 _L of the separator 102
It comprises a an exhaust system path 103 which emits a high density air out of the apparatus, O ₂ flowing out from the high pressure side 102 _H of the separator 102
High-concentration air can be supplied to the inside of the machine again through the circulation system path 101. With this configuration, the remaining O ₂ can be selectively captured and reused.
The burden on the enrichment section and the O ₂ cylinder can be reduced, and as a result, the overall device can be reduced in size and weight.

The performance of the separation membrane 102a is generally represented by the permeation amount Q of the gas to be separated, the permeation coefficient of the gas is P, the membrane area is S, the film thickness is l, and the glass partial pressure on the high pressure side is P _IN , It is known that the gas partial pressure on the low pressure side is given by P _OUT as Q = PS (P _IN −P _OUT / l... (1). is necessary to increase the differential pressure acting on the separation membrane 102a (P _iN -P _OUT) to a, for this, pressurized by the compressor 104 to the high pressure side 102 _H in the illustrated configuration, the vacuum pump a low pressure side 102 _L It is configured to suck at 105.

[Problem to be Solved by the Invention] However, when the above configuration is actually applied, there is a problem that the CO ₂ removal efficiency decreases with time after the start of operation. The present inventors have studied the cause, separation film 102a large amount of CO ₂ which has passed through the accumulate on the low pressure side 102 _L in the separator 102, gradually CO on the low pressure side 102 _L of the separation film 102a
₂ It became clear that the concentration increased and P _OUT increased and the differential pressure decreased. Further, as a problem associated therewith, the low-pressure side 102 _L O ₂ partial pressure in the low pressure side 102 _L decreases in order to evacuate a result the high pressure side 102 _H useful O ₂ separation membrane than necessary of Starting from the point at which the gas passes through the separation membrane 102a, the point at which a large differential pressure acts on the separation membrane 102a tends to cause breakage of the separation membrane 102a.
And the provision of the vacuum pump 105 increases the size of the apparatus.

The present invention has been made in view of the above problems, and has as its object to effectively solve them with a simple structure.

[Means for Solving the Problems] The present invention employs the following means to achieve the above object.

That is, the aircraft air reproducing apparatus of the present invention, selection and circulation passage for circulating the cabin air, a large amount of CO ₂ more than the least O ₂ is interposed the circulation path from the high pressure side to the low pressure side A separator having a function of separating, and an exhaust system connected to the low pressure side of the separator and discharging the separated high CO ₂ concentration air to the outside of the device, comprising a separator from the high pressure side of the separator. in a highly leaked O ₂ concentration air that is configured to be capable of supplying again in the apparatus through the circulation passage, the low pressure side of the separator, the outside air introduction pathway for introducing the outside of the natural airflow Is connected.

[Operation] cabin air mainly comprising CO _2, O _2, N ₂ is introduced into the high pressure side of the separator, the main component O _2, N ₂ is the low pressure side, CO ₂
An out-of-plane natural airflow containing almost no airflow is introduced. More specifically, CO ₂ is about 0.03% with respect to N ₂ : 78% and O ₂ : 21%. Then, while the inside air is pressurized, the outside air is relatively low in pressure, and in this state, a differential pressure acts on the separation membrane. Thus, mainly CO ₂ is transmitted to the low pressure side from the high pressure side, CO ₂ which was transferred to the low pressure side is discharged to the outside from the exhaust system path riding natural airflow without staying.
On the other hand, the air with a high O ₂ concentration that has been removed from the high pressure side after CO ₂ has been removed is supplied again into the machine and used as breathing air.

Thus, in this configuration, the CO ₂ concentration on the low pressure side of the separation membrane does not increase even after a lapse of time from the start of operation. For this reason, regarding the CO ₂ partial pressure, a required differential pressure can always be secured between the CO ₂ partial pressure and the high pressure side, and the permeation can be promoted. In addition, there is no need to evacuate the low-pressure side at all.

If the low-pressure side is not evacuated, the O ₂ partial pressure on the low-pressure side increases. Therefore, regarding the O ₂ partial pressure, the differential pressure between the high pressure side and the high pressure side is reduced, and as a result,
The permeation suppression effect on O ₂ in the circulation system will work.

[Embodiment] An embodiment of the present invention will be described below with reference to FIG. 1 and FIG.

This air regenerating device is applied to, for example, a commercial aircraft, and a circulation system for sucking air A of a cabin 1 accommodating a passenger a by a blower (not shown) and circulating the air A to supply the air to the cabin 1 again. 2 are arranged.
In addition, a filter 3 and a separator 4 are provided in the circulation path 2. As the filter 3, a filter having a filtering function capable of removing minute dust and dust (such as cigarette smoke) is used. The separator 4 is typically provided with a tubular separation membrane 4a as shown in the figure, and has a structure in which a large number of such separation membranes 4a are bundled. The intended transmission coefficient permeability coefficient for reduced CO ₂ for at least O ₂ The material of the separation membrane 4a is large, for example, polydimethylsiloxane is used. The permeability coefficient of polydimethylsiloxane is generally known as O ₂ : CO ₂ = 1: 5.3.
The inside of the separation membrane 4a is connected to the circulation path 2, and the high pressure side _4H
Becomes The outside of the separation membrane 4 is connected to the exhaust line 5 as a low pressure side 4 _L. The other end of the exhaust path 5 is open to the outside of the machine.

In this embodiment, in this embodiment, a natural air flow (ram air) outside the machine is provided on the low pressure side 4 _L of the separator 4.
The outside air introduction path 6 for introducing B is connected. The outside air introduction path 6 has an introduction end opened outside the machine, and the ram air B
Can be led to the low-pressure side 4 _L without extremely impairing the flow velocity. Similarly, the ram air B introduced to the low-pressure side 4 _L is provided so as to be able to be discharged to the outside of the machine while minimizing the flow velocity thereof.

Note that the middle return circulation path 2, O ₂ gas cylinder 7 via the mixing valve or the like Yes connected, newly added the required amount of O ₂ to O ₂ collected by the separator 4, which Can be transferred to the cabin 1.

Thus, when the flight is performed while driving the illustrated reproducing apparatus, the CO ₂ in the cabin 1 gradually increases due to the breathing of the passenger a.
After the concentration increases and the air A is intermittently purified by the filter 3, it is introduced into the high pressure side 4 _H of the separator 4. Its components are mainly composed of CO ₂ , N ₂ and O ₂ . On the other hand, the low pressure side 4 of the separator 4
Ram air B mainly composed of N ₂ and O ₂ circulates through _L , and the ram air B blows out of the machine through the exhaust system path 5 without interruption. The CO ₂ concentration in ram air B is almost nil (about 350 ppm). Further, while the in-machine air A is pressurized, the ram air B is at a relatively low pressure, and by introducing these, a certain pressure difference acts on the separation membrane 4a. As a result, CO ₂ permeates from the high-pressure side 4 _H to the low-pressure side 4 _{L according} to the above-described equation (1), and is transferred to the low-pressure side 4 _L.
O ₂ is discharged as a mixed flow C with the ram air B from the exhaust system 5 without stagnation. On the other hand, the air D having a high O ₂ concentration flowing out from the high pressure side 4 _H merges with O ₂ newly supplied from the O ₂ cylinder 7 on the way, becomes fresh air E, is transferred into the cabin 1 again, and boarded. It is used as breathing air for the person a.

Thus, according to this configuration, there is no over time since the start of operation to the low-pressure side 4 _L separator 4 such as CO ₂ stays relates CO ₂ partial pressure, always high-pressure side 4 _H And a required differential pressure can be secured. For this reason,
In the separation membrane 4a, a stable permeation amount Q is generated throughout, and as a result, O ₂
The supply amount of O ₂ from the cylinder 7 is reduced, so that the mounting amount of the cylinder can be reduced.

Further, paying attention to the partial pressure of O _2, because O ₂ in the ram air B is introduced into the low-pressure side 4 _L separator 4, the differential pressure between the high-pressure side 4 _H becomes possible to reduce the reverse. Therefore, it is assumed that (1) the O ₂ with the circulation pathway 2 According to equation will be reduced ratio that passes through the separation membrane 4a, may be more heavily recycled without discarding valuable O ₂ .

Here, FIG. 2 shows an experimental result by the configuration shown in FIG. S is the membrane area [m ² ], O ₂ is the permeation amount [N / min], Q _AIR is the amount of ram air introduced at 4 _L on the low pressure side [N / min], and Q _BO is the O ₂ necessary for occupant breathing. O ₂ bomb consumption occupant per person in the case of supply from a cylinder and [N / min], taking the ratio _{Q AIR / (Q AIR + Q} 2) is plotted on the horizontal axis, and taking the S or Q _BO vertical axis ( The solid line relates to S, the dashed line relates to Q _BO .
Also tried to compress with a compressor when introducing to
C represents the compression ratio in that case). These measurement conditions are: flight altitude 40,000 ft, cabin supply gas pressure P ₁ = 399
[MmHg], O ₂ concentration of 58%, membrane permeated gas pressure P ₂ = 141 [mmHg]
(= Ram air pressure), respiratory volume = 26.3 [N / min], and CO ₂ concentration of supplied gas ≦ 0.3%.

As shown by the experimental results, as the ratio of the ram air introduction amount Q _AIR to the low-pressure side 4 _L increases (approaches 1), even if the membrane area S is smaller, the permeation gas pressure P ₂ is lower than the predetermined required permeation gas pressure P ₂ . With this, the required amount of CO ₂ can be removed.
If the film area S is constant, the required amount of CO ₂ can be removed under the required permeated gas pressure P ₂ without increasing the in-machine air A as the ram air introduction amount Q _AIR increases. For this reason, according to the present embodiment, the exhaust means such as the vacuum pump conventionally provided for promoting the separation of CO ₂ is not required, and not only does not need to be provided with the power, but also the difference in performing the vacuum exhaust is required. Since there is no need to apply pressure to the separation membrane 4a, it is possible to prevent breakage of the membrane and increase the life. Further, advantages can be obtained in various points, such as making the membrane area S smaller to reduce the size and weight of the membrane module, or reducing or eliminating the compressor.

In addition, such characteristics are the same for the O ₂ cylinder supply amount. As shown by the broken line in the figure, as the ram air introduction amount Q _AIR increases, the required O ₂ cylinder supply amount decreases, and the O ₂ cylinder supply amount decreases. If constant, the compressor can be eliminated by increasing the ram air introduction amount Q _AIR .

As mentioned above, although one Example of this invention was described, the structure of each part is not limited to the example of illustration. For example, the material of the separation membrane is
As long as the separation ratio of CO _{2 to} O ₂ is high, another one can be used as appropriate. Further, when the air inside the machine is compressed by the compressor, practically various deformations are performed everywhere, such as lowering the air having a high O ₂ concentration on the way to return.

[Effects of the Invention] As described above, the present invention connects an outside air introduction system for introducing a natural air flow outside the apparatus to the low pressure side of the separator, and removes CO ₂ permeated to the low pressure side in the separator. Since it is released outside the aircraft without stagnation, even if time passes
The permeation amount does not decrease due to an increase in the CO ₂ concentration, and it does not hinder long-term use.
This also for O ₂ partial pressure of the low-pressure side is increased,
O ₂ becomes more difficult to permeate through the separation membrane, and as a result, useful O ₂ flowing through the circulation system can be effectively prevented from being discarded along with CO ₂ . Further, in order to obtain a required permeation amount, the low pressure side of the separator is suctioned by a vacuum pump,
Alternatively, it is almost unnecessary to greatly increase the pressure on the high pressure side, so that the peripheral equipment can be reduced in size and simplified, and the effect of extending the life of the separation membrane can be obtained.

[Brief description of the drawings]

1 and 2 show an embodiment of the present invention, FIG. 1 is a schematic explanatory diagram of the structure, and FIG. 2 is a graph showing the experimental results. FIG. 3 is an explanatory view of a configuration corresponding to FIG. 1 showing a conventional example. 2 Circulation system 4 4 Separator 4 _H High pressure side 4 _L Low pressure side 5 Exhaust system 6 External air introduction system

Claims (1)

(57) [Claims] 1. A circulation pathway that circulates the cabin air, a large amount of CO ₂ more than the least O ₂ is interposed the circulation path
A separator having a function of selectively separating water from the high pressure side to the low pressure side, and an exhaust system connected to the low pressure side of the separator and discharging the separated high CO ₂ concentration air to the outside. ,
In those constituting the air high O ₂ concentration flowing out from the high pressure side of the separator so as to again supplied to the cabin through the circulation passage, the low pressure side of the separator, introducing the outside of the natural airflow An air regenerating device for an aircraft, which is connected to an outside air introduction system for performing the operation.