1、_ 6$(7HFKQLFDO6WDQGDUGV%RDUG5XOHVSURYLGHWKDW7KLVUHSRUWLVSX EOLVKHGE6$(WRDGYDQFHWKHVWDWHRIWHFKQLFDO and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefrom, LVWKHVROHUHVSR
2、QVLELOLWRIWKHXVHU SAE reviews each technical report at least every five years at which time it may be revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions. Copyright 2016 SAE International All rights reserved. No part of this publication may be reproduced,
3、 stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: +1 724-776-4970 (outside USA) Fax: 724-776-
4、0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/AIR825/14 AEROSPACE INFORMATION REPORT AIR825/14 Issued 2010-06 Reaffirmed 2016-03 Basic Aircraft Oxygen Syste
5、ms Design RATIONALE AIR825/14 has been reaffirmed to comply with the SAE five-year review policy. FOREWORD The third revision of AIR825, Oxygen Equipment for Aircraft, generated such a large volume of information that the document became cumbersome to use. See AIR825/1 for a full list of slash docum
6、ents, topics and history. This document is one of 14 slash documents that are comprised of existing AIR825 documents plus new information. Anyone who is new to oxygen requirements for aircraft will find all slash 14 documents beneficial. In contrast, someone with extensive experience may want to onl
7、y obtain one or two of the slash documents. TABLE OF CONTENTS 1.SCOPE 31.1Purpose . 32.APPLICABLE DOCUMENTS 52.1SAE Publications: 52.2CFR their performance will be determined empirically. The establishment of these values will allow the calculation of the dependent variables, the regulator performan
8、ce curves, and an oxygen requirement curve. The oxygen requirement curve is then used to evaluate the oxygen quantity requirements. The required oxygen flow is that quantity of oxygen flow required by the system to ensure that all passenger masks will have at least the minimum oxygen required. Once
9、the required quantity of oxygen has been established, an average or overall value of system oxygen utilization efficiency can be determined. For overall system design, it is desirable to achieve the highest efficiency level possible. This will be discussed in Section 3.3.6, System Efficiencies This
10、passenger system evaluation and calculation does not include an analysis of the quantity of first aid oxygen required for commercial transport operations under CFR 121.333 or JAR OPS 1.760. The passenger system analysis begins with the requirements of the airplane systems most remotely located passe
11、nger oxygen mask where the oxygen distribution line pressure drop is at its maximum (See Figure 1, point E). This persons mask must provide the CFR required minimum quantity of oxygen, but may be the least amount of any one mask associated with the distribution system. The specific mask performance
12、characteristics will determine the minimum flow required at the mask. The flow that is delivered is based on the outlets orifice performance, which determines the pressure control regulators pressure required to the outlet orifice (See Figure 1, point E). The pressure required at the outlet adjusted
13、 for the distribution system pressure drop will determine the pressure schedule of the pressure control regulator (See Figure 1, point B).SAE INTERNATIONAL AIR825/14 3 OF 45PRESSURIZEDOXYGENCYLINDERPRESSUREGAUGESHUT-OFFVALVEB A GB A GB A GORIFICECABIN ATMOSPHERICPRESSUREMANIFOLDASSYOUTLET TOMANIFOLD
14、SPOINT DPOINT APOINT BOUTLETS TOMANIFOLDSMEDIANOUTLETSPOINT C BLEEDVALVECAPPASSENGER MASKPOINT EFIGURE 1 PASSENGER SYSTEM SCHEMATICSAE INTERNATIONAL AIR825/14 4 OF 452. APPLICABLE DOCUMENTS The following publications form a part of this document to the extent specified herein. The latest issue of SA
15、E publications shall apply. The applicable issue of other publications shall be the issue in effect on the date of the purchase order. In the event of conflict between the text of this document and references cited herein, the text of this document takes precedence. Nothing in this document, however
16、, supersedes applicable laws and regulations unless a specific exemption has been obtained. 2.1 SAE PublicationsAvailable from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-000, Telephone:877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org.AS8025 Passeng
17、er Oxygen Mask 2.2 CFR %O2 = Percentage of added O2Air = Total mixture air %Air = Percentage of air added O2 = Total Fraction of Oxygen in the Nitrogen-Oxygen Mixture Oxygen Air AddedOxygenAdded O%2 1Air% O% 2 2O%-1Air% Air%0.2095 O% mask at O% Total 22 SAE INTERNATIONAL AIR825/14 12 OF 45)O% -(1 0.
18、2095 O% mask at O 222 0.79050.2095 -mask at O Added O% 22 Or7) (Eq See 79.05 20.95) -Oxygen % (Total Oxygen Added ofFraction TABLE 3.1 - COMPOSITION OF THE ATMOSPHERE (DRY AIR) Constituent Gas Molecular Fraction PercentMolecular Weight Nitrogen (N2) 78.08 28.0134 Oxygen (O2) 20.95 31.9988 Argon (A)
19、0.93 39.948Carbon Dioxide (CO2) 0.03 44.009510Air (mixture)* 100.00 28.9644Values based on the 1999 table Pure Appl. Chem., or Pure Appl. Chem. Vol. 73, No. 4, pp. 667-683 (2001)* includes trace elementSAE INTERNATIONAL AIR825/14 13 OF 45FIGURE 2 EQUIVALENT ATTITUDESSAE INTERNATIONAL AIR825/14 14 OF
20、 453.1.4 Variables 3.1.4.1 The independent variables used for this example are: a. Passengers mask performance determined by performance testing per TSO-C64b and SAE document AS8025A. b. Passenger manifold orifice performance determined empirically. c. Design safety margins. 3.1.4.2 The dependent va
21、riables used for this example are: a. The supplemental oxygen requirement curve; i.e., the cylinder oxygen flow required per passenger versus altitude. b. Oxygen system line pressure drop by analysis or by previous testing. c. The supplemental oxygen line pressure control regulator performance curve
22、. 3.2 Requirements 3.2.1 Theoretical Oxygen Requirements The bases for the following calculations are CFR as well the equivalent CS and JAR requirements. 3.2.1.1 Physiological Requirements CFR 25.1443 paragraph (c) states the following: “For passengers and cabin attendants, the minimum mass flow of
23、supplemental oxygen required for each person at various cabin pressure altitudes may not be less than the flow required to maintain, during inspiration and while using the oxygen equipment (including masks) provided, the following mean tracheal oxygen partial pressures: a. At cabin pressure altitude
24、s above 10 000 feet up to and including 18 500 feet, a mean tracheal oxygen partial pressure of 100 mm. Hg. when breathing 15 liters per minute, BTPS, and with a tidal volume of 700 cc. with a constant time interval between respirations. b. At cabin pressure altitudes above 18 500 feet up to and inc
25、luding 40 000 feet, a mean tracheal oxygen partial pressure of 83.8 mm. Hg. when breathing 30 liters per minute, BTPS, and with a tidal volume of 1,100 cc. with a constant time interval between respirations.” AS8025 provides testing procedures to determine the minimum oxygen flow to meet the above r
26、equirements. Aircraft Operational Requirement a. Per CFR 121.329(c) and the equivalent JAR OPS. “Each certificate holder shall provide a supply of oxygen for passengers in accordance with the following: 1. For flights at cabin pressure altitudes above 10 000 feet, up to and including 14 000 feet, en
27、ough oxygen for that part of the flight at those altitudes that is of more than 30 minutes duration, for 10 percent of the passengers. 2. For flights at cabin pressure altitudes above 14 000 feet, up to and including 15 000 feet, enough oxygen for that part of the flight at those altitudes for 30 pe
28、rcent of the passengers. 3. For flight at cabin pressure altitudes above 15 000 feet, enough oxygen for each passenger carried during the entire flight at those altitudes.” SAE INTERNATIONAL AIR825/14 15 OF 45b. Per CFR 121.333(e) and the equivalent JAR OPS. “When the airplane is operating at flight
29、 altitudes above 10 000 feet, the following supply of oxygen must be provided for the use of passenger cabin occupants:” (2) When an airplane is operated at flight altitudes up to and including flight level 250 and cannot descend safely to a flight altitude of 14 000 feet within four minutes, or whe
30、n an airplane is operated at flight altitudes above flight level 250, oxygen must be available at the rate prescribed by this part for not less than 10 percent of the passenger cabin occupants for the entire flight after cabin depressurization, at cabin pressure altitudes above 10 000 feet up to and
31、 including 14 000 feet and, as applicable, to allow compliance with 121.329(c)(2) and (3), except that there must be not less than a 10-minute supply for the passenger cabin occupants.” NOTE: It is not the intent of the regulation to provide for both item a) and b) of these situations but rather to
32、provide for the larger of the two so that the quantity of oxygen could meet either condition. 3.2.2 Determination of the Theoretical Oxygen Requirements Although the theoretical flow oxygen requirements bear no direct relation to the actual cylinder oxygen flow requirements, they will be evaluated f
33、irst since they will be needed subsequently to evaluate the overall efficiency of the passenger oxygen utilization, and serve to establish estimates of the actual needs. These calculations (see Table 4) are based on CFR, JARs, and CS Part 25 and results of testing per AS 8025 to meet TSO C64a, as qu
34、oted under Passenger System Design requirements (see section 3.3). SAE INTERNATIONAL AIR825/14 16 OF 45TABLE 4 CALCULATIONS(1) (2) (3) (4) (5) (6) (7) (8) Cabin Cabin Cabin Conversion Total Total % Fraction of TheoreticalAltitude Barometric Barometric BTPS to Gas Oxygen Added Oxygen Pressure Pressur
35、e NTPD Intake Required Oxygen 1000 Ft* kPa mm Hg NTPD/ BTPSLPM(NTPD)LPM (NTPD)At 15 LPM (BTPS) 10 69.68 522.66 0.5938 8.91 21.02 0.0009 0.01 11 67.02 502.69 0.5689 8.53 21.94 0.0126 0.11 12 64.44 483.35 0.5447 8.17 22.92 0.0249 0.20 13 61.94 464.61 0.5213 7.82 23.95 0.0379 0.30 14 59.52 446.47 0.498
36、7 7.48 25.03 0.0517 0.39 15 57.18 428.90 0.4768 7.15 26.18 0.0662 0.47 16 54.92 411.90 0.4555 6.83 27.41 0.0817 0.56 17 52.72 395.44 0.4350 6.52 28.70 0.0980 0.64 18 50.60 379.53 0.4151 6.23 30.07 0.1154 0.72 18.5 49.57 371.83 0.4055 6.08 30.79 0.1244 0.76 At 30 LPM (BTPS) 18.5 49.57 371.83 0.4055 1
37、2.17 25.80 0.0613 0.75 19 48.55 364.14 0.3959 11.88 26.42 0.0692 0.82 20 46.56 349.25 0.3773 11.32 27.73 0.0857 0.97 21 44.65 334.87 0.3594 10.78 29.11 0.1032 1.11 22 42.79 320.96 0.3420 10.26 30.59 0.1219 1.25 23 41.00 307.53 0.3252 9.76 32.17 0.1419 1.38 24 39.27 294.56 0.3090 9.27 33.85 0.1632 1.
38、51 25 37.60 282.03 0.2934 8.80 35.66 0.1860 1.64 26 35.99 269.94 0.2783 8.35 37.59 0.2105 1.76 27 34.43 258.27 0.2637 7.91 39.66 0.2367 1.87 28 32.93 247.01 0.2497 7.49 41.90 0.2650 1.98 29 31.49 236.16 0.2361 7.08 44.30 0.2954 2.09 30 30.09 225.69 0.2231 6.69 46.90 0.3282 2.20 31 28.74 215.60 0.210
39、5 6.31 49.70 0.3637 2.30 32 27.45 205.88 0.1983 5.95 52.74 0.4022 2.39 33 26.20 196.52 0.1867 5.60 56.05 0.4440 2.49 34 25.00 187.51 0.1754 5.26 59.64 0.4894 2.58 35 23.84 178.83 0.1646 4.94 63.57 0.5391 2.66 36 22.73 170.48 0.1542 4.62 67.86 0.5935 2.74 37 21.66 162.48 0.1442 4.33 72.56 0.6529 2.82
40、 38 20.65 154.86 0.1346 4.04 77.69 0.7178 2.90 39 19.68 147.59 0.1256 3.77 83.31 0.7888 2.97 40 18.75 140.67 0.1169 3.51 89.47 0.8668 3.04 * Multiply Feet by 0.3048 to obtain MetersSAE INTERNATIONAL AIR825/14 17 OF 45The elements of Table 4 are as follows: Column 1 - Cabin Pressure Altitude - in inc
41、rements of thousands of feet between 10 000 and 40 000 ft. Column 2 - Cabin Barometric Pressure (PB) - in kPa for each corresponding cabin altitude.Column 3 - Cabin Barometric Pressure (PB) - in mm Hg for each corresponding cabin altitude. Column 4 Conversion BTPS to NTPD - Conversion Factor for con
42、verting BTPS to NTPD. This is done because, when working with hardware, NTPD is used for consistency. When specifying physiological requirements, however, BTPS is used. This factor is equal to the cabin barometric pressure minus the water vapor 47 mm Hg divided by 760 mm Hg, then corrected for tempe
43、rature. The temperature in Fahrenheit is converted to Rankin. 2) (Eq 76094877.047P NTPD toBTPSor1) (Eq )6.9869.459(760 )7069.459)(47(P NTPD toBTPSBB Column 5 - Total Gas Intake - from mask required to maintain the minimum mass flow of supplemental oxygen. These values are obtained as follows; For Ca
44、bin Altitude between 10 000 and 18 500 feet: 3) (Eq AltitudeCabin each for NTPD toBTPSfactor conversion LPM 15 LPM Total u For Cabin Altitudes between 18 500 and 40 000 feet: 4) (Eq AltitudeCabin each for NTPD toBTPSfactor conversion LPM 30 LPM Total u Column 6 - Total Percent Oxygen Required percen
45、t oxygen concentration in the dry gas supplied to the trachea necessary to maintain the required partial pressure of oxygen. From section 3.2.1.1 we know the required mean tracheal oxygen for the different Cabin Altitudes are known. So the calculations are as follows: For Cabin Altitudes between 10
46、000 and 18 500 feet: 5) (Eq percent 10047PmmHg 100 Oxygen % Total BFor Cabin Altitudes between 18 500 and 40 000 feet: 6) (Eq percent 10047PmmHg 83.8 Oxygen % Total BColumn 7 - Fraction of Added Oxygen- is determined as follows:(For the complete derivation see Table 3) SAE INTERNATIONAL AIR825/14 18
47、 OF 457) (Eq 79.05 20.95) -Oxygen % (Total Oxygen Added ofFraction Column 8 - Theoretical Oxygen LPM (NTPD) - physiological requirement for each cabin altitude. It is calculated as follows: 8) (Eq Oxygen) Added ofaction (NTPD)(Fr LPM Intake Gas (Total Oxygen lTheoretica 3.3 Passenger System Design 3.3.1 Mask Parameters For the purposes of our hypothetical airplane system design we will assume that the passenger mask meets FAA Technical Standard Order (TSO) C64b requirements. This TSO ensures that the mask provides sufficient added oxygen to a
