JPS5812457B2 - hydrogen engine - Google Patents

Description

[Detailed description of the invention] The present invention relates to improvements in hydrogen engines.

In general, in an engine using hydrogen fuel, as shown in Fig. 1, when hydrogen fuel is ignited by one spark plug 2 installed on one side of a combustion chamber 1, propagation occurs as shown by the broken line in the figure. By the time the combustion flame reaches the combustion chamber wall 3 facing the ignition plug, the temperature near the ignition plug 2 that burned first becomes extremely high.

Furthermore, the farther the combustion flame propagates, the higher the temperature near the spark plug 2 becomes.

This is because when the combustion flame propagates from where it was first ignited by the spark plug, the pressure in the vicinity of the spark plug increases due to the combustion that accompanies the flame propagation, which causes the temperature to rise. As the propagation distance of the flame increases, the combustion time associated with the flame propagation becomes longer, so the time that the combustion chamber wall is exposed to high temperature becomes longer, and as a result, the temperature of the combustion chamber wall becomes even higher.

In this way, when the temperature near the spark plug 2 becomes high,
There is also the problem that the concentration of NOx in the combustion gas increases abnormally in the vicinity, and a hot surface is formed on the combustion chamber wall in the vicinity, reducing the durability of that part and causing flashback.

In order to solve the above-mentioned problems, the present invention shortens the distance over which the combustion flames propagate by allowing a plurality of combustion flames ignited by a plurality of spark plugs to meet in the center of the combustion chamber. It is characterized by suppressing the temperature rise.

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 2 shows an embodiment of a hydrogen engine according to the present invention, in which a plurality of spark plugs 13, 13 are provided on a peripheral wall 12a of a combustion chamber 120 formed by slidably inserting a piston 11 into a cylinder 10. , ......, an appropriate number of mechanical or electromagnetic fuel valves 14 for supplying hydrogen fuel to the peripheral wall 12a of the combustion chamber near the spark plug 13, and an intake valve 16 on the upper wall 12b of the combustion chamber. An intake pipe 15 with an exhaust valve 18 and an exhaust pipe 17 with an exhaust valve 18 are provided.

The plurality of spark plugs 13 in the hydrogen engine are arranged oppositely so that a plurality of combustion flames of hydrogen and air generated by ignition with the respective spark plugs meet in the center of the combustion chamber 12. It is also possible to arrange two spark plugs facing each other as illustrated in the figure, or four spark plugs as illustrated in FIG.

In the hydrogen engine having the above configuration, the combustion chamber 12
Air is supplied into the engine through the intake pipe 15, hydrogen fuel is supplied through the fuel valve 14 in the middle of the compression stroke and mixed, and this mixture is mixed with a plurality of spark plugs 13, 13, . . .
When ignited, a plurality of combustion flames meet in the center of the combustion chamber 12, so the propagation distance of the combustion flames becomes short, thereby suppressing a significant temperature rise in the vicinity of the spark plug.

That is, when the propagation distance of the combustion flame is shortened by the plurality of spark plugs, the time during which the vicinity of the spark plug is compressed due to combustion of fuel accompanying the propagation of the flame is shortened, and the temperature rise is suppressed accordingly.

However, the center of the combustion chamber where multiple combustion flames meet is the first
The temperature becomes higher than in the case shown in the figure, and by increasing the combustion rate, the degree of isovolume increases, and the average temperature inside the cylinder increases.

Note that the timing and amount of hydrogen fuel supplied through each of the fuel valves 14 and the ignition timing of each spark plug 13 do not necessarily need to be the same, and may vary depending on the shape of the combustion chamber 12 and The combustion flame may be set so as to meet at the center of the combustion chamber 12, taking into account the flow of air and hydrogen fuel within the combustion chamber 12, and also considering the efficiency of the engine.

As described above, according to the hydrogen engine of the present invention, the propagation distance of the combustion flame ignited by each spark plug can be shortened and the temperature rise near the spark plug can be suppressed, so the concentration of NO, in the combustion gas can be reduced. In the case of hydrogen fuel, if only this NOx is reduced, other harmful gases will not be generated, so the exhaust gas can be extremely purified, and by suppressing the temperature rise mentioned above, ignition The formation of a hot surface on the combustion chamber wall near the plug can be prevented to improve cylinder durability and also prevent flashbacks from occurring.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a combustion chamber in a comparative example with the present invention;
FIG. 2 is a longitudinal cross-sectional view of a hydrogen engine according to the present invention, and FIGS. 3 and 4 are cross-sectional views of combustion chambers in different embodiments. 12... one combustion chamber, 13... spark plug.

Claims (1)

[Claims] 1. In an engine that operates by supplying air and hydrogen fuel, multiple spark plugs are provided on the wall of the combustion chamber, and multiple combustion flames of hydrogen and air generated by each spark plug are ignited at the center of the combustion chamber. A hydrogen engine characterized in that the above-mentioned spark plugs are arranged oppositely so that they meet at the parts.