Double-fuel homogeneous compression ignition/quasi-homogeneous compression compound combustion system

Abstract

A double fuel homogeneous compression ignition / quasi-homogeneous compression ignition combustion system is composed of a diesel tank, a gas tank, a high pressure common track spray device, a gas channel spray device, cooled waste gas recycle device and an electronic control unit, among which, the diesel tank and the gas tank are connected with the engine via the high pressure spray device and gas recycle device is connected with the inlet and discharge tubes of the engine, the input of the engie work state output by the engine and the output is connected with the common track spray device, gas channel device and the cooled waste gas recycle device.

Description

[0001] Field: [0002] The invention belongs to a combustion system of an engine, in particular to a dual-fuel homogeneous compression ignition / quasi-homogeneous compression ignition composite combustion system. Background technique: [0003] At present, the application of natural gas in the engine mainly has the following types: 1. The traditional ignition method is used for port injection or intake air mixing. The disadvantage of this method is that due to the limitation of knocking, the compression ratio of the engine is low, so the thermal efficiency is low. , high fuel consumption rate; on the other hand, due to the flame propagation process, the flame front generates a large amount of NOx emissions, which requires the use of noble metals such as platinum as a post-processing device for catalysts; at the same time, due to the high octane number of natural gas, high-energy spark plugs are required . The second is to adopt the diesel / natural gas dual fuel method, which is ...

AI Technical Summary

Problems solved by technology

[0003] At present, the application of natural gas in the engine mainly has the following types: 1. The traditional ignition method is used for port injection or intake air mixing. The disadvantage of this method is that due to the limitation of knocking, the compression ratio of the engine is low, so the thermal efficiency is low. , high fuel consumption rate; on the other hand, due to the flame propagation process, the flame front generates a large amount of NOx emissions, which requires the use of noble metals such as platinum as a post-processing device for catalysts; at the same time, due to the high octane number of natural gas, high-energy spark plugs are required

The second is to adopt the diesel / natural gas dual fuel method, which is ignited by diesel oil. The advantage of this scheme is that it can use the same compression ratio as the diesel engine, which improves the thermal efficiency of the engine. Incomplete, its thermal efficiency is lower than that of diesel engines; it can significantly reduce soot emissions, but has limited effect on reducing NOx emissions, and this method cannot use the currently widely used three-way catalyst, so it must meet the more stringent emission regulations in the future tougher

The third method is liquefied natural gas (LNG) in-cylinder direct injection lean combustion technology, which adopts the ignition method to realize stratified lean combustion in the cylinder. At present, this technology is not widely used in practice, and the main problem is still NOx emission. During the propagation process, the flame front will generate a large amount of NOx. Since the air-fuel ratio is greater than 1, the current three-way catalytic reactor cannot be used, and a DeNOx after-treatment device is required. This technology is not yet mature and difficult; at the same time, due to the Local over-concentrated areas exist, and improper combustion organization can easily generate soot

Therefore, it is still difficult for this scheme to meet the limit requirements of future strict emission regulations

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