A cold start system for flexible fuel vehicles

Abstract

The invention relates to a cold start system of a flexible fuel vehicle, which includes an engine control unit, a fuel system and a fuel preheating module; the fuel preheating module includes a water temperature sensor, a preheating indicator light, a power output module and a heating spray oiler. After the start switch is turned on, the preheat indicator light is on first, the water temperature sensor transmits the cooling water temperature signal to the engine control unit, and the engine control unit calculates the duty ratio signal to judge whether the output power of the power output module is required; The output current of the fuel injector. While heating the ethanol fuel, the heating injector feeds back the temperature signal of the heating injector to the engine control unit for judging the end time of warm-up.

Description

technical field [0001] The invention belongs to the field of engines, and specifically refers to a cold start system and a start method of an ethanol flexible fuel vehicle. Background technique [0002] Since ethanol flexible fuel vehicles use ethanol as the main fuel, cold starts are not ideal. Since the evaporation of ethanol stops at 12°C, the ethanol fuel cannot be atomized after being injected into the engine manifold. A homogeneous gas mixture cannot be formed. When entering the engine cylinder for ignition, the ethanol fuel cannot be ignited effectively at this time, which brings difficulty to cold start. [0003] In order to solve this problem, two schemes are usually used to heat the fuel oil of the engine fuel rail and the auxiliary fuel tank system. The fuel oil rail is used to heat the ethanol fuel above the evaporation point so that it can form an effective mixture; or the auxiliary fuel tank heating system is used. Ignite the engine with gasoline fuel from th...

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Problems solved by technology

[0008] The disadvantage of this solution is that when the fuel is heated, because the fuel cannot flow, the efficiency of heat conduction is low, resulting in local overheating of the fuel, and the heating time is too long

Using this starting scheme, it takes nearly 1 minute to heat the fuel. Moreover, since the fuel inside the engine injector cannot be heated, the first fuel injection of the engine cannot be ignited smoothly, which will cause higher emissions.

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