Fundamental test results of a hydraulic free piston internal combustion engine
Fundamental test results of a hydraulic free piston internal combustion engine
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DOI：
10.1177/095440700421801010
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发表时间：
2004-10
期刊：
影响因子：
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通讯作者：
A. Hibi;T. Ito
中科院分区：
文献类型：
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作者：
A. Hibi;T. Ito
本文所研制的液压自由活塞内燃机泵为对置活塞式、二冲程循环、直流扫气、燃油直喷、压燃式。对置的发动机活塞直接使液压泵活塞往复运动，并且产生要在液压马达中使用的液压动力。所产生的液压基本上是恒定的。相对的自由活塞在每个气体循环之后静止，并且液压动力在自由活塞静止期间由液压蓄能器连续地供应。液压流量输出越小，休息的持续时间越长。每个气体循环都在固定的工况下进行，与液压功率输出无关。试验结果表明，自由活塞发动机泵的每秒气体循环次数与液压流量输出成正比。当液压流量输出为1.02 cm 3/s时，对置自由活塞每53.2 s运行一次;此时液压功率输出为0.0124 kW。在0.0124 kW至4.88 kW的液压功率输出范围内测量了液压热效率，即产生的液压能量与消耗的燃料能量的比率，并且已经清楚的是，在该范围内的液压热效率是恒定的。水力热效率的实测值为31%，证明了即使在很小的水力输出下，水力热效率也是恒定的。
Abstract The hydraulic free piston internal combustion engine pump that has been constructed and tested in this work is the opposed piston, two-stroke cycle, uniflow scavenging, direct fuel injection, and compression ignition type. The opposed engine pistons reciprocate the hydraulic pump pistons directly and the hydraulic power to be used in the hydraulic motors is generated. The hydraulic pressure generated is substantially constant. The opposed free pistons rest after every gas cycle and hydraulic power is continuously supplied by a hydraulic accumulator during the free pistons' rest. The smaller the hydraulic flow output, the longer the duration of the rest. Every gas cycle is performed under a fixed working condition independent of hydraulic power output. The test results in this work indicate that the number of gas cycles per second of the free piston engine pump is directly proportional to hydraulic flow output. The opposed free pistons operate every 53.2 s when hydraulic flow output is 1.02 cm3/s; at that time hydraulic power output is 0.0124 kW. Hydraulic thermal efficiency, the ratio of hydraulic energy produced to fuel energy consumed, has been measured in the range 0.0124 kW to 4.88 kW of hydraulic power output and it has become clear that hydraulic thermal efficiency in this range is constant. The measured value of hydraulic thermal efficiency is 31 per cent. It has been demonstrated that hydraulic thermal efficiency is kept constant even if hydraulic power output is very small.