| 摘要 |
<p>In a gas combustion engine (1), which is manufactured by conversion of a diesel engine, the piston form, the compression ratio, the air intake system (5) and the exhaust gas system (3) are modified. The exhaust gas system is hereby split into two parts (7, 9), each of which consists of an exhaust branch-piece and a catalyser (19, 20), whereby catalysers of standard format can be employed, and the air intake system (5) is made smaller, whereby the probability of backfire is reduced. The hollow (67) in the piston (47) already present in the diesel engine is enlarged in diameter and depth, in such a manner that the ratio of the diameter to the depth is equal to 30:11. In this manner, one achieves an optimal form with respect to heat extraction. In addition, enlargment of the hollow (67) causes a lowering of the compression ratio to a value of 1:10, which is necessary when applying gas as a fuel. In addition, the edge (63) of the piston (47) near the top surface (65) of the piston (47) is bevelled, in order to compensate for extra expansion of the piston (47) around the hollow (67), which extra expansion occurs as a result of the increased combustion temperatures. The costs of the above-specified conversion of a diesel engine to a gas combustion engine (1) are hardly higher than those of a revision service of a diesel engine, so that there is no longer a financial obstacle to conversion to gas as a fuel.</p> |
