System for recycling water in engine waste gas and then injecting water into inlet gas

Abstract

The invention relates to a system for recycling water in engine waste gas and then injecting the water into inlet gas. The system comprises a heat exchanger, a cooling liquid outlet bypass valve, a cooling liquid outlet bypass pipeline, a first water vapor condensation separator, a second water vapor condensation separator, a recycling water tank, a water spraying assembly (water injector), an exhaust aftertreatment device, an exhaust bypass valve, a terminal exhaust pipe, an EGR valve, an EGR pipeline and an electronic control unit (ECU). Moisture in the waste gas is recycled and removed, and then the recycled condensate water is sprayed into a gas inlet channel through a water injector and enters an engine combustion chamber after being mixed with fresh charge, so that the combustion temperature in a cylinder is reduced, and the risk of NOx emission and abnormal combustion is effectively reduced; and meanwhile, the sustainability and the running mileage of the air inlet water injection function of an engine are greatly improved, the cyclic utilization rate of water is increased, condensed accumulated water in an EGR system is reduced, the control precision and the stability of the EGR system are improved, and the service life of the EGR system is prolonged.

Description

technical field [0001] The invention relates to the technical field of engines, in particular to a system for recovering moisture in engine exhaust gas and injecting it into intake air. Background technique [0002] Worries about the energy crisis have forced engine technology worldwide to develop towards high performance, low fuel consumption and even energy transformation. Technologies such as supercharging, increasing compression ratio, and direct injection in cylinders have been successfully applied, and clean alternative energy sources such as hydrogen In recent years, it has also been vigorously developed in the engine. However, due to the increase in cylinder temperature, the high performance and high power of the engine and the use of alternative fuels, especially hydrogen, also increase the risk of abnormal combustion of the engine such as knocking and early ignition, which is more serious under medium-to-high load and extreme working conditions . Not only that, n...

AI Technical Summary

Problems solved by technology

However, the use of intake water injection technology creates additional water demand for the engine, which requires a certain amount of water to be reserved for the engine and regular filling due to consumption, which undoubtedly increases the burden on the engine system and reduces intake water injection to a certain extent The running time of the function

In addition, the use of intake water injection also leads to a further increase in the water content in the engine exhaust

Patent CN201710527603.0 proposes an engine water injection system that recycles EGR condensed water, but only recycles the water in the EGR exhaust gas, because usually the EGR exhaust gas only accounts for a part of the exhaust gas, and changes with the operating conditions of the engine and the The demand for EGR changes, so the amount of recovered water is not only limited but also changes with the change of EGR rate, and sometimes EGR is not even performed, such as idling conditions

In addition, since there is no condenser, condensed water may continue to accumulate in the EGR cooler and piping before the EGR mixer, affecting EGR control and corroding parts

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