Fuel supply and engine control system (fig. 9.1):
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–supplies fuel to the engine combustion chamber;
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– controls TC and free turbine (MR) RPM within required for operational power settings range;
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– limits maximum indicated TC RPM;
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– limits maximum reduced TC RPM parameter;
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– controls air bypass valves operation;
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– controls engine automatic start up;
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– synchronizes engines power;
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– controls position of engine compressor variable geometry vanes;
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– prevents free turbine over speeding;
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– automatically readjusts engine electronic governor for emergency power setting in case of single engine failure;
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– controls TC RPM at idle power setting.
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Required fuel designation..………………………………..
| ….….
| ТС–1 acc. ГОСТ 10227-86
РТ acc. ГОСТ 10227-86
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It is allowed to use any fuel type of foreign production listed in chimmotology list 078 00 5700ДХК
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Cleanliness of fuel, serviced in helicopter tanks…………..
| …..…
| not worse than 8th class according ГОСТ 17216-71
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Fuel pressure at engine booster pump inlet:
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|
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during start up………………………….….
| ……...
| 0,4 – 1,2 kgf/сm2 (excessive)
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at operational power settings:
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|
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altitude Н=0……………..…….……….
| ….….
| 0,7 kgf/сm2 (absolute)
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altitude Н=4 km/………………………..
| ……...
| 0,3 kgf/сm2 (absolute)
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At altitude Н=6 км and fuel type Т-2, used upon special permission authorization..……………………………..
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….….
| 0,4 kgf/сm2 (absolute)
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maximum:
|
|
|
if engine operates.…………………..…
| …..…
| 2,8 kgf/сm2 (excessive)
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if engine is inoperative.……………..…
| …..…
| 2,8 kgf/сm2 (excessive)
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Fuel pressure before fuel nozzles in the I
manifold, at takeoff power………………….…………..…
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….….
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not more than 60 kgf/сm2
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System components:
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|
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1. Fuel control unit……………..…………………..….
| ….….
| НР–3ВМА
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2. Fuel booster pump…………………………………..
| ….….
| ДЦН–70А
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3. Fuel nozzles…………….……………………….….
| ……...
| 12 pc – centrifugal, double orifice
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4. Fine fuel filter, equipped by pressure switch…………………………………………...…
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….….
|
8Д2.966.236
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5. Engine electronic governor…………………………
| ….….
| ЭРД – 3ВМ
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6. Actuating unit……………….…………………..…..
| ….….
| ИМ–3А
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7. Free turbine RPM transmitter…………...................
| ….….
| ДТА–10, 4 pc
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8. Turbo compressor RPM transmitter……………..…
| …..….
| ДЧВ–2500, ДЧВ–2500А
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9. Temperature probe in engine inlet….…………….…
| ….….
| П–109 or П–77
|