| 摘要 |
1291030 Starting diesel engines FRANCE ARMED FORCES MINISTER OF 30 April 1971 [5 May 1970] 12312/71 Headings F1B and F1G Exhaust turbo-supercharged Diesel engine having a compression ratio of less than 12 has a combustion chamber 3 external to the engine 1, which receives part of the fresh air from the compressor 2, and supplies combustion gas to the turbine 4, additionally to that received from the engine, independent means 6 are provided to bring the compressor-turbine unit to selfmaintaining operation and the minimum speed of the unit is sufficient to create in the intake pipe of the engine, conditions of temperature and pressure which permit its starting and slow speed operation. Combustion chamber 3 receives a quantity of fuel controlled by a device 7 e.g. an electric pump, the delivery rate of which is proportional to its supply voltage. In a modification, Fig. 2 (not shown) all or part of the exhaust gas is fed to the combustion chamber and mixes with the air. In an engine having two-stage supercharging, the air for the combustion chamber may be taken from the outlet of either the L.P. or H.P. stages and mixed with all or part of the exhaust gases from the engine. In an engine having, for example, a compression ratio of 8, the temperature in the intake pipe must be 80‹C. to obtain auto-ignition at the end of the compression stroke. If the ambient temperature is 0‹C., then the temperature ratio in the compressor must be 1À3, requiring a pressure ratio of 2. The speed of the supercharging unit is determined by the necessity to achieve this pressure ratio.
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