COMBUSTION CONTROL METHOD AND SYSTEM IN NATURAL GAS ENGINE Russian patent published in 2021 - IPC F02D19/08 F02D41/30 F02B69/04 

FIELD: engine building.

SUBSTANCE: invention can be used in engines operating on natural gas. Method for controlling combustion in an engine on natural gas comprises determining, on the basis of the current operating parameter of the engine on natural gas, the operating state of the engine. Number of full injection of natural gas and pilot diesel fuel required by engine in this operating condition is calculated. Diffusion combustion mode with direct injection is performed in case operating state is idle or low load state. Diffusion combustion mode with direct injection is a mode in which diesel fuel is injected at a top dead compression point and then injecting natural gas. Compression ignition mode is performed with active control of hybrid homogeneous natural gas in case when working state is average load condition. Compression ignition mode with active homogeneous natural gas control is a mode in which natural gas is injected after closing the inlet valve, and diesel fuel is injected at the moment to upper compression dead point. Total injection amount is divided into three parts including amount of natural gas injection at compression ignition, the amount of pilot diesel fuel injection and the amount of natural gas injection during diffusion combustion, in the case when the working state is a high load condition. Natural gas is injected in amount of natural gas injection at compression ignition into combustion chamber so that it is mixed with air inside combustion chamber at early stage of engine compression stroke on natural gas. Injection, at moment near upper dead point of compression or at large angle of advance of injection of diesel fuel, diesel fuel in amount of pilot diesel fuel injection into combustion chamber in order to ignite pre-injected natural gas. Natural gas is injected after preset time interval in amount of natural gas injection at diffusion combustion into combustion chamber. This early stage of compression stroke begins from the moment of time when the crankshaft turns at least 10 degrees after the inlet valve closing. In the case when the operating condition is a high load state, distribution of the amount of natural gas injection during compression ignition, amount of injection of pilot diesel fuel and amount of injection of natural gas during diffusion combustion is optimized according to the following rule during combustion in an engine on natural gas. Reducing the amount of natural gas injection during compression ignition, reduced amount of injection of pilot diesel fuel and increased amount of injection of natural gas during diffusion combustion with increase of engine load on natural gas. System for controlling combustion of an engine on natural gas is disclosed.

EFFECT: technical result consists in improvement of thermal efficiency and power of engine on natural gas.

12 cl, 2 dwg