Waste gas-fuel reforming and recycling natural gas engine system and control method

Abstract

The invention discloses a waste gas-fuel reforming and recycling natural gas engine system and a control method. The waste gas-fuel reforming and recycling natural gas engine system comprises an engine, a fuel supply device, a gas tank used for supplying to the fuel supply device, a reformer and an intercooler. Engine fuel is directly subjected to a multiple reforming reaction with O2 and water vapor, so that reformed gas which is rich in H2 and CO is generated, and H2 production efficiency is high; online production of hydrogen is achieved, an extra fuel storage device or an extra hydrogen storage tank does not need to be provided, the safety is improved, and the size of the whole system is reduced; two pass tubes are adopted, so that the heat transfer coefficient is increased, and the reforming efficiency is improved accordingly; the reformed gas contains a large quantity of H2, the in-cylinder combustion speed is increased, and the lean burning extreme is widened; the oxygen concentration in a gas inlet pipe can be decreased through circulating waste gas, the specific heat capacity of working media is improved, and the in-cylinder combustion temperature is decreased; and by combining the reformed gas with the circulating waste gas, stable low-temperature lean burning of the natural gas engine can be achieved, and meanwhile, the HC concentration, the CO concentration and the NOx concentration can be decreased.

Description

technical field [0001] The invention belongs to the technical field of LNG engines, and in particular relates to an exhaust gas-fuel reforming recirculation natural gas engine system and a control method. Background technique [0002] Under the dual effects of energy crisis and environmental protection, finding alternative energy sources and reducing pollutant emissions has become a hot topic in the field of internal combustion engine research. As a high-quality alternative fuel for engines, liquefied natural gas (LNG) has the advantages of high energy density, easy transportation, and good combustion effect. When the engine burns natural gas, it has the advantages of low carbon dioxide, sulfide and particulate matter emissions, so it has been vigorously developed. [0003] For natural gas engines, low temperature lean burn technology is often used to suppress knock and nitrogen oxide (NOx) emissions. However, an excessively high air-fuel ratio will lead to engine misfire,...

AI Technical Summary

Problems solved by technology

However, an excessive exhaust gas recirculation rate will lead to unstable combustion, resulting in increased cycle fluctuations, and even misfires, while increasing CO and HC emissions

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