Method for preventing spark plug of natural gas engine from freezing in low-temperature environment

Abstract

The invention relates to a method for preventing a spark plug of a natural gas engine from freezing in a low-temperature environment. The method comprises the following steps that an environment temperature is obtained; whether the environment temperature is lower than a manually preset spark plug anti-freezing upper limit temperature threshold value or not is judged; if the environment temperature is not lower than the spark plug anti-freezing upper limit temperature threshold value, the previous step is executed; if the environment temperature is lower than the spark plug anti-freezing upper limit temperature threshold value, an engine scavenging mode is started; the environment temperature is obtained again; whether the environment temperature is lower than the manually preset spark plug anti-freezing upper limit temperature threshold value or not is judged, and the following operation is executed according to the judgment result: if the environment temperature is not lower than the spark plug anti-freezing upper limit temperature threshold value, the engine scavenging mode is closed, and then the first step is executed; and if the environment temperature is lower than the spark plug anti-freezing upper limit temperature threshold value, the previous step is executed. According to the method, gas convection is formed, the exhaust efficiency is improved, water vapor is possibly and completely exhausted, the probability and severity of freezing are reduced, and spark plug flashover is avoided; water vapor is prevented from entering a combustion chamber; and shutdown is conducted in time, the equipment loss is reduced and the service life of a battery is prolonged.

Description

technical field [0001] The invention relates to the technical field of natural gas engine system control, in particular to a method for preventing spark plugs from freezing in a low-temperature environment of a natural gas engine. Background technique [0002] The natural gas engine relies on burning natural gas to do work in the engine cylinder; the current natural gas engine is still ignited by a spark plug after inhaling the mixture of natural gas and air; the combustion products of natural gas are mainly carbon dioxide and water vapor; although the natural gas engine There is an exhaust stroke, which can discharge most of the natural gas combustion products, but there is still a small amount of water vapor that inevitably stays in the engine cylinder. [0003] And because natural gas engines use natural gas as fuel; and one of the characteristics of natural gas is that the calorific value is generally low; therefore, the current mainstream natural gas engines will design...

AI Technical Summary

Problems solved by technology

[0046] 1. Because only the exhaust valve is opened during the exhaust process, while the intake valve is closed, there is no intake air inside the engine, resulting in no gas convection, which makes the exhaust efficiency very low, and the water vapor cannot be completely discharged;

[0047] 2. Since the engine needs to continue to run for a period of time after shutdown, the engine cannot be shut down in time, which not only increases equipment loss, but also increases the risk of engine failure;

[0048] 3. Since the engine will no longer burn natural gas to work after the engine is shut down, most of the existing technologies rely on the motor to maintain the engine speed during the exhaust time of the natural flameout method, and this process requires the vehicle battery to provide large current support , resulting in a sharp increase in battery power consumption and greatly reducing the life of the vehicle battery

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