SAE J 1775-2015 Bleed-Air Pneumatic Systems for Gas Turbine Equipped Marine and Amphibious Craft.pdf

1、 SURFACE VEHICLE INFORMATION REPORT J1775 MAY2015 Issued 1984-11 Revised 2015-05 Superseding J1775 MAY2013 Bleed-Air Pneumatic Systems for Gas Turbine Equipped Marine and Amphibious Craft RATIONALE Revised to complete document conversion from (Aerospace) Hydrospace Information Report HIR 1559 to Sur

2、face Vehicle Information Report SAE J1775; References were updated, Section 2.2 was added for related (but not directly cited) references, Section 3.1 was updated to add reliability improvements using PLC controlled air valves. Section 3.4.1 was updated to add reference to SAE J1781 to replace listi

3、ng of nitrogen strengthened and precipitation hardened alloys, and to suggest consideration of heat pipe (tube) materials to reduce scaling in salt water cooling. Section 3.5 was updated to add reference MIL-STD-1472 for guidelines for maximum effective environmental temperature in manned spaces. 1.

4、 SCOPE This Information Report provides a description of bleed-air pneumatic system elements and identifies parameters required to define the requirements for a detailed specification. Specific design requirements are dependent on the application and should be incorporated in a detailed specificatio

5、n. 1.1 Purpose This Information Report is intended to provide basic design considerations with respect to bleed-air pneumatic systems for marine craft equipped with gas turbine propulsion engines or gas turbine service power units with compressor bleed-air capability. It is not considered within the

6、 scope of this Information Report to cover the equipment driven by this bleed air or other sources of pneumatic power such as power driven compressors. 1.2 Classification This report is applicable to marine surface craft, air cushion vehicles, captured air bubbles, surface effect ships, hydrofoils a

7、nd other advanced marine craft, such as small water area twin hull (SWATH), equipped with gas turbine propulsion or gas turbine power units. 2. REFERENCES 2.1 Applicable Documents The following referenced publications form a part of this specification information report to the extent specified herei

8、n. Unless otherwise indicated, the latest issue of SAE and all referenced publications shall apply when developing requirements for incorporation into a design specification. _ SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and en

9、gineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefrom, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it m

10、ay be revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions. Copyright 2015 SAE International All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanica

11、l, 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: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SAE values your input. To

12、provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/J1775_201505 SAE INTERNATIONAL J1775 Revised MAY2015 Page 2 of 7 2.1.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and

13、 Canada) or 724-776-4970 (outside USA), www.sae.org. SAE ARP699 High Temperature Pneumatic Duct Systems for Aircraft SAE J1781 Ship Systems and Equipment - Materials for Fluid Systems. 2.1.2 Military Publications Available from DLA Document Services, Building 4/D, 700 Robbins Avenue, Philadelphia, P

14、A 19111-5094, Tel: 215-697-6396, http:/quicksearch.dla.mil/. MIL-S-901 Shock Tests, H.I. (High Impact), Shipboard Machinery, Equipment and Systems, Requirements for (Navy) MIL-STD-167-1 Mechanical Vibrations of Shipboard Equipment (Type I Environmental and Type II Internally Excited) MIL-STD-777 Sch

15、edule of Piping, Valves, Fittings, and Associated Piping Components for Naval Surface Ships MIL-STD-1472 Human Engineering 2.2 Related Publications The following publications are provided for information purposes only and are not a required part of this information report. 2.2.1 SAE Publications Ava

16、ilable from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org. SAE ARP1796 Engine Bleed Air Systems for Aircraft 2.2.2 Military Publications Available from DLA Document Services, Building 4/D, 70

17、0 Robbins Avenue, Philadelphia, PA 19111-5094, Tel: 215-697-6396, http:/quicksearch.dla.mil/. MIL-C-19713 Coolers, Fluid, Bleed Air, Gas Turbine, Naval Shipboard MIL-STD-740-2 Structure Vibratory Acceleration Measurements and Acceptance Criteria of Shipboard Equipment MIL-STD-1474 Noise Limits 3. BL

18、EED-AIR PNEUMATIC SYSTEM System elements and design parameters are identified and discussed in this section. Careful consideration must be given to bleed air system efficiencies and penalties. These factors are discussed only briefly in this information report and the designer should consult the gas

19、 turbine manufacturer and other sources to ensure that a bleed air system is appropriate for that particular application. SAE INTERNATIONAL J1775 Revised MAY2015 Page 3 of 7 3.1 Bleed Airflow The term “bleed-air“ identifies the airflow used to drive pneumatic systems and that is available from a gas

20、 turbine used as propulsion or auxiliary power unit and is used to drive pneumatic systems. Bleed airflow limitations are specified in the gas turbine specifications and are normally 5 to 10 percent of the total airflow through the engine. To minimize the use of the bleed-air flow is important to av

21、oid adverse effects on fuel consumption and useful power. The reduction of bleed-air extraction can be attained by proper selection of the driven equipment, a suitable distribution system and controls, and the appropriate management of the power available, like scheduling and/or intermittent duty cy

22、cle. Some gas turbines require surge avoidance valves to vent a portion of compressor airflow during certain engine operating conditions. The requirements of this surge avoidance bleed system are independent of the pneumatic system bleed. The surge avoidance vents must be discharged overboard to avo

23、id adverse effects to the local environment and adjacent equipment. Development of Programmable Logic Controller (PLC) controlled bleed air valves to monitor and control air flow has improved bleed air system flexibility and system reliability. 3.2 Pressure Bleed-air pressure level is dependent on e

24、ngine power setting and ambient air temperature. The pressure is minimum at idle and maximum at full power. The distribution system should be designed to withstand a proof pressure of 150 percent of the maximum engine bleed port pressure, with the component at the associated temperature for the most

25、 adverse pressure and temperature condition that occurs during operation. Distribution system components should be designed to withstand a burst pressure of 250 percent of the maximum engine bleed pressure, with the component at the associated temperature for the most adverse pressure and temperatur

26、e condition that occurs during normal operation. 3.3 Temperature Bleed-air temperature level is dependent on engine power setting and ambient air temperature; it increases with higher engine power settings. Bleed-air temperature levels of marine gas turbines approach 540 C (1000 F). The use of heat

27、exchangers to limit the bleed-air temperature to the specified system temperature becomes a requirement. The maximum temperature level must be compatible with the controls and equipment of the system and, most important; it must be maintained below that limit to avoid critical effects on other syste

28、ms (fuel, hydraulic and lube) and accessories. The safety devices selected must be of the redundant and fail safe type. 3.4 Ducting Ducting includes runs, joints, control components and supports. The geometry of the system, as well as the type of craft in which the system is used, dictates the type

29、of supports: rigid or elastic to minimize dynamic interaction between the primary and secondary structure of the craft and the ducting; i.e., the hot air ducting must be structurally independent of the ship or craft structure. A thorough analysis is recommended, economic and operational factors shou

30、ld be brought together to arrive at the selection of system or systems. The use of insulation could be mandatory in some areas, and the selection must be based on safety and reparability. 3.4.1 Materials The high temperature and the marine salt-air environment significantly increase the corrosion su

31、sceptibility of the material selected. In the case of amphibious craft, the erosive effect of the sandy environment must be added to the important parameters considered when selecting the materials. The selection of fastener type and material is as important as the selection of materials for the duc

32、ting and supports. The gas turbine bleed-air section of MIL-STD-777 may be used as guidance in the selection of piping and component materials. Additional guidance for selecting corrosion resistant materials for fluid systems is provided in SAE J1781. SAE ARP 699 presents useful information concerni

33、ng the materials available for design of the ducting and some components. Where salt water is used as the coolant for high temperature bleed air, heat pipe cooler technology can reduce scaling. The heat pipe coolers control tube wall temperatures below salt water scaling temperature (less than 65C (

34、150F). SAE INTERNATIONAL J1775 Revised MAY2015 Page 4 of 7 3.4.2 Loads The effect of thermal expansion, duct end loads, deflections due to ship or craft motions, undue accelerations, and linear and angular misalignment are paramount in the design and installation of the distribution system. A clear

35、understanding of the ship or craft motions at different attitudes and operational modes is mandatory for the proper evaluation of the loads that is additive to airflow, pressure, temperature, vibration and shock-induced loads. 3.4.2.1 Vibration The vibration criteria established in MIL-STD-167-1 sho

36、uld be considered as part of the loading system. Vibration induced by high velocity flow in metal bellows should be considered for the selection of flow liners and the determination of the dynamic system of loads. 3.4.2.2 Shock For combatant vehicles, shock loads outlined in MIL-S-901 should also be

37、 considered in the analysis of the design loads. 3.4.2.3 Fatigue The combination of pressure, temperature and marine environment demands a thorough study of material fatigue and cycling of the system. All components must be properly qualified to this respect. Concerning the actual system, the number

38、 of thermal cycles must be determined and specified. The physical and mechanical properties of the materials selected must be in agreement with loading and temperature effects on stress levels and endurance, fracture properties and galvanic coupling. Special attention must be rendered to joints, sup

39、ports and geometrical changes due to temperature. The question of external loads due to shock and vibration must be well identified and the proper dynamic loading must be superimposed, if anticipated. Provisions must be established in the maintenance instructions to inspect those areas or components

40、 of the overall system that are susceptible to initiate any kind of failure, and also to schedule replacement of those items that are part of the system and whose safe and useful life is defined. 3.4.3 Leakage Duct connections, control and components interfaces must be sealed to eliminate the leakag

41、e of hot air to the environment and adjacent components. 3.4.4 Supports As mentioned in 3.4, the supports could be of the rigid or elastic type. Supports must be located as close as practicable to fittings, control components, vents, etc., to minimize overhang. Dynamic analysis must be performed, es

42、pecially in high speed craft, when dynamic coupling can be significant. 3.4.5 Moisture All ducting should be installed such that accumulated moisture can drain to drain ports or vent through dedicated equipment. A centrifugal air/water separator or other device for water removal should be installed

43、downstream of each heat exchanger. Desiccators should be considered for moisture protection of sensitive equipment only if they will not pose a maintenance burden. 3.4.6 Location Components should be located for ease of access to inspect, adjust and repair, when necessary. System should be designed

44、to allow removal and replacement of sections of ducting and components without requiring removal of the remaining ducting or components. Ducts should be routed to minimize any maintenance support requirements. Components susceptible to freezing should be installed where collection of moisture can be

45、 avoided or equipped with drains. SAE INTERNATIONAL J1775 Revised MAY2015 Page 5 of 7 3.4.7 Damage Protection When bleed-air ducting is routed, maximum care should be taken such that leakages of high-temperature air from ducting and components could not cause damage to structure and to adjacent comp

46、onents. If this leakage could result in fire and explosion hazards, provisions to detect bleed-air leakage must be installed. Where dual ducts used to provide redundancy, their routing should be fully independent of each other to attain that redundancy. Advantage should be taken of structural compon

47、ents to isolate ducting from potential hazards and battle damage. Main shutoff valves should be installed in the duct system as close to the bleed-air source as practical to permit shutdown in the event of system rupture. If the valves are remotely activated, they should be designed to return to the

48、 closed position upon failure. If the system serviced by bleed-air is critical to the ships operation or safety, a signal should be provided to the ships or crafts control station to indicate the shutoff valves are closed to aid in determining the operation. 3.4.8 Branch Circuits Systems with branch

49、 circuits to supply airflow to various subsystems should include isolation shutoff valves to separate failed circuits. 3.4.9 Compartment Isolation Penetrations of bleed-air ducting through watertight bulkheads should be appropriately sealed and isolated on each side by an isolation shutoff valve. The valves can be manual or automatic with a manual override. 3.4.10 Noise Airflow noise generated in relief valves, vents and ducting