JPH0361198A - Air regenerating device for aircraft - Google Patents

Abstract

PURPOSE:To reduce the amount of consumption of O2 cylinders by separating the circulating air inside an aircraft into a high CO2 concentration air and a low CO2 concentration air, and by introducing ram air into the high CO2 concentration air, so that the high CO2 concentration air can be discharged by the ram air to the outside of the aircraft. CONSTITUTION:The air inside a cabin 1 is sent to a separator 4 through a circulating passage 2 via a filter 3. In the separator 4, only CO2 is permeated by a separation membrane 4a having a larger CO2 permeability and a lower O2 permeability to separate a high O2 concentration air from a high CO2 concentration air. And, by introducing ram air B into the low-pressure side 4L having a high CO2 concentration through an outside-air introducing passage 6, the high CO2 concentration air is discharged by the ram air B to the outside of the aircraft through a discharge passage 5. On the other hand, the high O2 concentration air on the high-pressure side is supplied with O2 from a cylinder 7 in the circulating passage 2, and then is returned to the cabin 1. By this constitution, the amount of consumption of O2 cylinders can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an air regeneration device for an aircraft for regenerating breathing air exhaled by a passenger and supplying the same to the passenger again.

[Prior Art] The popular 02 partial pressure decreases with altitude. Therefore, in order to continuously supply the air passengers with the 02 necessary for breathing, appropriate means are required. Generally, small high-performance aircraft are equipped with a concentrator for condensing engine bleed air with 02 gas, and even commercial aircraft are equipped with equipment such as 02 cylinders.

However, all of these facilities do not allow passengers such as 11j to
The purpose is only to supply air, and no measures are taken against the air exhaled by passengers. For this reason,
The air exhaled by the passengers was carelessly discarded along with the large amount of 02 remaining in it, resulting in the inconvenience of having to supply more than necessary 02 from the 02 enrichment section or 02 cylinder.

Therefore, in order to solve these inconveniences, the present inventors recently proposed an air regeneration device having the following configuration.

That is, as shown in FIG.
A circulation system path 101 that circulates cabin air to the air, etc., and a separation membrane 102a installed in the circulation system path 101 and installed internally, transfer a larger amount of CO2 from the high pressure side 102o to the low overwhelming 102L at least compared to 02. A separator 102 that performs a selective separation function and a low pressure side 10 of this separator 102.
2□, and an exhaust system line 103 that discharges the separated air with a high concentration of CO2 to the outside of the machine, and the air with a high concentration of 02 flowing out from the high overflow 102H of the separator] 02 is connected to a circulation system. The fuel can be supplied to the cabin again through the route 101. With this configuration, the remaining 77 02
Since it can be selectively extracted and reused, the burden on the concentration section and the 02 cylinder can be reduced, and as a result, the entire device can be made smaller and lighter.

The performance of the separation membrane 102a is generally expressed as the permeation ff1Q of the gas to be separated, and the permeation coefficient of the gas is P,
The membrane area is S, the membrane thickness is ρ, the gas partial pressure on the high pressure side is PIN,
The gas partial pressure on the low pressure side is P. Q=PS (PIN
It is known that it is given by POUT ) /D - (1). As this formula reveals, the amount of transmission Q
In order to increase the differential pressure (
It is necessary to increase P IN P 0LIT ), and for this purpose, in the illustrated configuration, the high pressure side 102 There is.

[Problem to be solved by the invention] However, when the above configuration is actually applied, after the start of operation,
This causes a problem in which the insect removal efficiency of CO2 decreases over time. When the present inventor investigated the cause of this problem, it was discovered that a large amount of CO2 that had passed through the separation membrane 102a or the separator 10
[02a] 02a
The CO2 concentration on the low pressure side 102L of
It became clear that OU'l. increased and the differential pressure decreased. In addition, as a problem accompanying this, in order to evacuate the low pressure side 102 , , the low pressure side 102 t
02 partial pressure decreases, resulting in high pressure side 1021,
The useful 02 of 02 permeates through the separation membrane 102a more than necessary, and the separation membrane 102a is damaged due to the excessive pressure difference acting on the separation membrane 102a.
For example, the installation of the compressor 104 and the vacuum pump 105 requires a large amount of equipment.

The present invention has been made with attention to the following problems, and it is an object of the present invention to effectively solve these problems with a simple structure.

[Means for Solving the Problems] In order to achieve the above object, the present invention takes the following measures.

That is, the aircraft air regeneration device of the present invention includes a circulation system path that circulates cabin air, and a system that is interposed in this circulation path and selectively separates a larger amount of CO2 from the high pressure side to the low pressure side at least compared to 02. It is equipped with a separator having a function and an exhaust line connected to the low pressure side of the separator and discharging the separated air with a CO2 concentration of 1% to the outside of the machine, and the air is discharged from the high pressure side of the separator. In a device configured to be able to supply air with a high concentration of 02 into the aircraft again through a circulation system line, an outside air introduction line for introducing natural air flow from outside the machine is connected to the low pressure side of the separator. It is characterized by what it did.

[Function] In-flight air whose main components are CO2, 02, and N2 is introduced into the high-pressure side of the separator, and natural air flow from outside the aircraft whose main components are 02 and N2 and contains almost no CO2 is introduced into the low-pressure side. be introduced. Specifically, while N2: 8%, 02:21%, CO□: about 0.03%. Since the air inside the aircraft is pressurized, the air outside the aircraft is at a relatively low pressure, so a pressure difference acts on the separation membrane in this state. As a result, CO2 mainly permeates from the high-pressure side to the low-pressure side, and the CO2 that has moved to the low-pressure side is released from the exhaust system outside the machine along with the natural air flow without being retained. On the other hand, CO2
The air with a high concentration of 02, which has been removed and flows out from the high-pressure side, is again supplied into the cabin and used as breathing air.

With this configuration, the CO2 concentration on the low-pressure side of the separation membrane will not increase even after time has passed since the start of operation. Therefore, regarding the CO2 partial pressure, there is always a It is possible to secure a differential pressure of 100% and accelerate permeation. Moreover, for this purpose, there is no need to evacuate the low pressure side at all.

Furthermore, if the low pressure side is not evacuated, the 02 partial pressure on the low pressure side will increase. For this reason, regarding the 02 partial pressure, the differential pressure between the high pressure side and the high pressure side is reduced, and as a result, a permeation inhibiting effect on the 02 in the circulation system works.

[Example] An example of the present invention will be described below with reference to FIGS. 1 and 2.

This air regeneration device is applied to, for example, a commercial aircraft, and a circulation system is used to suck in air A from a cabin 1 accommodating a passenger A using a blower, etc. (not shown), circulate it, and supply it to the cabin 1 again. Route 2 is installed. A filter 3 and a separator 4 are interposed in this circulation path 2.

The filter 3 used has a filtration function that can remove microscopic dust and dirt (such as cigarette smoke).

The separator 4 is schematically provided with a tube-shaped separation membrane 4a as shown in the figure, and actually has a structure in which a large number of separation membranes 4a are bundled together.

The material used for the separation membrane 4a is at least one that has a low permeability coefficient for CO2 and a high permeability coefficient for CO2, such as polydimethylsiloxane. The permeability coefficient of polydimethylsiloxane is as follows:
02: CO2=1 +5°3. The inside of this separation membrane 4a is connected to the circulation system path 2 and becomes a high pressure side 4H. Further, the outside of the separation membrane 4 has a low pressure side 40. It is connected to the exhaust system line 5 as a. The other end of the exhaust system path 5 is open to the outside of the machine.

In this embodiment, in this embodiment, the low pressure side 41. An outside air introduction line 6 for introducing a natural air flow (ram air) B from outside the machine is connected to the outside air introduction line 6.

The outside air introduction line 6 has an introduction end opened outside the machine so that the ram air B can be introduced to the low pressure side 4L without significantly reducing the flow velocity. Similarly, the exhaust system path 5 is provided so that the ram air B introduced into the low pressure side 4□7 can be discharged to the outside of the machine while keeping its flow velocity as low as possible.

In addition, the 02 cylinder 7 is connected to the return mountain of the circulation system path 2 via a mixing valve, etc., and a new required amount of 02 is added to the 02 collected by the separator 4, and this is sent to the cabin. It is possible to transfer to 1.

However, when a flight is performed while operating the graphic reproduction device, the CO2 in the cabin 1 gradually increases due to the breathing of the passenger a.
After the concentration rises, the air A is intermittently purified by the filter 3 and then introduced into the high pressure side 4H of the separator 4. The main components are CO2 and N2.02. On the other hand, on the low pressure side 4L of the separator 4, ram air B containing mainly N2.02 is supplied.
is in circulation, and this ram air B is blown out of the machine through the exhaust system path 5 without any stagnation. The CO2 concentration in Lamnia B is almost zero (about 350 ppm). Furthermore, while the cabin air A is pressurized to Li, the ram air B is at a relatively low pressure, and by introducing these, a certain degree of differential pressure will act on the separation membrane 4a. As a result, the high pressure side 41. From the low pressure side 40, as already mentioned (1)
According to the formula, CO2 permeates and moves to the low pressure side 4□7
2 becomes a mixed flow C with ram air B and is discharged from the exhaust system passage 5 to the outside of the machine. On the other hand, the high pressure side 411
The air with a high concentration of 02 flowing out from the 02 cylinder 7 joins with the 02 newly supplied from the 02 cylinder 7 on the way, becomes fresh air E, and is transferred back into the cabin 1, where it is used as breathing air for the passenger a. Ru.

According to such a configuration, CO2 does not remain on the low pressure side 4L of the separator 4 even after time has passed since the start of operation, and the partial pressure of CO2 is always maintained on the high pressure side 41.
It is possible to secure the required differential pressure between 1 and 1. Therefore, the separation membrane 4a produces stable permeation (mQ) from beginning to end, and as a result, the amount of 02 supplied from the 02 cylinder 7 is reduced, and the amount loaded in the cylinder can be reduced.

Also, when the partial pressure reaches 02, the low pressure side 4 of the separator 4
Since 02 in the lumnia B is introduced into the +- side, the pressure difference between the high-pressure side 41 (and the high-pressure side 41) decreases.

Therefore, according to equation (1), the ratio of 02 in the circulation system path 2 passing through the separation membrane 4a is reduced, and the useful 02 is transmitted through the separation membrane 4a.
2 can be recycled in larger quantities without having to be discarded.

Here, FIG. 2 shows the results of an experiment using the configuration shown in FIG. 1. S is the membrane area [ril'], Q2 is the permeation amount [N27ml1nl], and QAIR is the amount of ram air introduced on the low pressure side 4L [N! :I/[[lin], QBo
02 cylinder consumption per crew member when all the 02 necessary for crew breathing is supplied from cylinders [N, ll)/m
1nl, and the horizontal axis represents the ratio QA□1. /(QA□l++Q
2), and the vertical axis is S or QBO (the solid line relates to S and the broken line relates to QBO. Also, the cabin air A
An attempt was also made to compress it with a compressor when introducing it into the separator 4, and PRC represents the compression ratio in that case). These measurement conditions were a flight altitude of 40,000 ft.

Cabin supply gas pressure P+ = 399 [mm11g]
, 02 concentration 58%, membrane permeation gas pressure P 2 = 141
[mmHg] (= ram air pressure), respiratory rate -26.3 [N
, 12/min, 1 The CO2 concentration of the supplied gas is ≦0.3%.

As shown by this experimental result, as the ratio of the ram air introduction amount Q A I R to the low pressure side 4.7 increases (as it approaches 1), even if the membrane area S is small, the preset required permeate gas pressure P2 It becomes possible to remove the required amount of CO2 under If the membrane area S is constant, as the ram air introduction amount QAIR increases, the required amount of CO2 can be removed under the required permeate gas pressure P2 without compressing the cabin air A so much. For this reason, according to Motoshio, the evacuation means such as vacuum pumps, which were previously provided to promote the separation of CO2, are no longer necessary, and there is no need to provide power for them, and the difference between vacuum evacuation and Since it is no longer necessary to apply pressure to the separation membrane 4a, damage to the membrane can be prevented and its life can be increased. Furthermore, advantages can be obtained in various respects, such as reducing the membrane area S to make the membrane module smaller and lighter, or reducing the size of the compressor or eliminating it.

In addition, these characteristics are the same for the 02 cylinder supply amount, and as shown by the broken line in the top of the figure, the ram air introduction f
As fl Q A I R increases, the required 02 cylinder supply amount is reduced, and if the 02 cylinder supply amount is constant, the compressor can be made unnecessary by increasing the ram air introduction amount QAIR.

Although one embodiment of the present invention has been described above, the configuration of each part is not limited to the illustrated example. For example, the basic value of a separation membrane is 0
Other materials can also be used as appropriate as long as they have a high separation ratio of CO2 to CO2. Further, when the cabin air is compressed by a compressor, the pressure of the air with high 02 concentration on the way back is lowered, and various other practical modifications can be made.

[Effects of the Invention] As described above, the present invention connects the outside air introduction line for introducing natural airflow from outside the machine to the low pressure side of the separator, and retains CO2 that has permeated to the low pressure side in the separator. Since the CO2 concentration is released outside the machine without causing any damage, the CO2 concentration does not increase over time and the amount of permeation does not decrease, making it possible to use the product for long periods of time without any problems. . In addition, this increases the partial pressure of 02 on the low pressure side, making it more difficult for 02 to pass through the separation membrane, and as a result, useful 02 flowing through the circulation system is not discarded along with CO2. It can also be effectively prevented. moreover,
In order to obtain the required amount of permeation, it is almost unnecessary to use a vacuum pump to suck the low-pressure side of the separator or to greatly increase the pressure on the high-pressure side, which reduces the size and size of peripheral equipment and extends the life of the separation membrane. will be obtained.

[Brief explanation of drawings]

FIGS. 1 and 2 show an embodiment of the present invention, with FIG. 1 being a schematic diagram for explaining the configuration, and FIG. 2 being a graph showing experimental results. Further, FIG. 3 is an explanatory diagram of a configuration corresponding to FIG. 1 showing a conventional example.

Claims (1)

[Claims] a circulation system path for circulating cabin air; a separator interposed in the circulation system path and having a function of selectively separating at least a larger amount of CO_2 than O_2 from the high pressure side to the low pressure side;
It is equipped with an exhaust system line connected to the low pressure side of the separator and discharging the separated air with a high concentration of CO_2 to the outside of the aircraft,
In a device configured such that air with high O_2 concentration flowing out from the high pressure side of the separator can be supplied into the machine again through the circulation system, a natural air flow from outside the machine is introduced into the low pressure side of the separator. An air regeneration device for an aircraft, characterized in that an outside air introduction system is connected to the air regeneration system.