Hydrogen Cars with LH
-Pump and Cold GH
-Injection Two-Stroke Engine
According to results of a number of studies made in past concerning premixed hydrogen-air engines, the problems lay in the low output, backfire and NOx emission. In addition, the necessity to reduce the fuel tank weight and volume for automobile application existed.
In order to meet these requirements, Musashi Institute of Technology in Tokyo developed a method as an ideal fuel system, by inserting a small-sized LH2-pump in a LH2-tank, forcing high pressure LH2 into a low temperature and high pressure gas hydrogen container of 1ℓ or so, and injecting cold GH2 of −30 to −50°C during the first half of the compression stroke of a two-stroke engine. In this manner, two passenger cars were tried, with a 3-cylinder and 0.55ℓ engine installed in one of them and a 3-cylinder and 1.1ℓ engine installed in the other.
It was demonstrated through engine dynamometer tests and on-vehicle tests on a test course that above mentioned problems could be all solved. Engine maximum power was improved by 20 to 30% as compared with gasoline engines, and backfire was prevented completely.