The fuels of diesel generators and gasoline generators are different. Generally speaking, diesel is more likely to catch fire than gasoline, which seems difficult to understand. Gasoline and diesel are made from hydrocarbon compounds made up of two elements: carbon and hydrogen. Gasoline is made up of hydrocarbons with 5 to 9 carbon atoms, while the hydrocarbons that make up diesel contain 10 to 20 carbon atoms. Since gasoline molecules are smaller than those in diesel, gasoline is more volatile and burns faster, but diesel has a long chain. The structure oxidizes more easily, so the auto-ignition point of diesel is lower than that of gasoline.
The auto-ignition point of diesel is lower than that of gasoline, so diesel can ignite spontaneously in the cylinder at high temperature and high pressure; if the enginegasoline uses compression ignition, it must have a higher pressure and thus obtain a higher temperature. It needs to be ignited, but because gasoline volatilizes easily, it absorbs a lot of heat when it volatilizes, which further increases the difficulty of compression ignition, so ignition with a spark plug is the most appropriate way. .
Gasoline evaporates more quickly than diesel, so gasoline can enter the cylinder in a mixed state during the suction stroke. Diesel does not volatilize easily and cannot easily form a mixture, so it can only be injected directly into the cylinder. cylinder before the start of the power stroke inside.
Gasoline burns faster than diesel, so putting gasoline in a high temperature and high pressure environment is too powerful, and the body cannot withstand this kind of powder quenching cannon. Ptherefore, the pressure in the cylinder must be reduced. reduced, and a spark is used to ignite the cylinder. The internal flame spreads and burns in the form of "waves", which avoids the impact of deflagration while the diesel burns in many places at the same time to form high temperature flames; and high pressure air, that is, in the form of deflagration (similar to the "detonation" of gasoline engines) "Similar") works, and the operating state is relatively harsh, but because diesel burns more slowly, although combustion starts violently, the combustion time is still longer than that of a gasoline engine.
What are the common faults of gasoline generators
Sa and other generator tips: In most cases, this is because your generator may be overloaded !
Causes of chimney fires in gasoline generators
LChimney fires in gasoline engines are usually caused by unburned fuel or oily deposits blown out of the chimney with high-temperature gas and then burned. in the air, that is, the continuation of the fuel combustion process in the cylinder. Let’s take a look at the detailed explanation from generator accessories manufacturer Sardon.
1. Sparks formed by burning oil mist are difficult to detect during the day, but small, short light pink sparks can be seen coming out of the chimney at night. Most of the sparks go out in the stream of smoke that follows them, without any carbon or black particles falling. This situation often occurs when the gasoline engine is overloaded, the fuel atomization in some cylinders is poor, or the air supply to the cylinder is insufficient. The fuel injected into the cylinder cannot be completelyburned and there is excessive oil mist or fine oil droplets. in the cylinder are evacuated by the high temperature. When gas is fed directly out of the chimney, it burns when it encounters oxygen.
2. Sparks formed by burning residual oil. These sparkles are slightly longer in shape and darker in color than those above. They rush into the sky from the chimney and drift with the wind before dying out. fine carbon particles and soot ribbons. This usually occurs when some injectors of a gasoline engine drip oil or have poor combustion during low load operation, especially when the exhaust system temperature and pressure are low for a period of time. long time, unburned oil often accumulates in the exhaust pipe, even if it is removed from the chimney, it is difficult to ignitesea by low temperature gas. Some old gasoline engines use the boiler exhaust gas bypass method to vent the gas directly to avoid contamination of the heating coil in the boiler. On modern ships, most bypass smoke exhaust pipes have been removed. The gas can only be discharged through the exhaust gas boiler, and the exhaust back pressure increases. Therefore, the accumulation of oil in the flue of a two-stroke gasoline engine operating at low load will gradually increase. The accumulated residual oil has undergone a physical and chemical preparation process before ignition. If there is enough air, when the exhaust temperature is higher than 210°C or an open flame is encountered, it will catch fire at the chimney outlet inside the exhaust. pipe.
3. Sparks formed by burning depositsof soot. Most sparks emitted from the chimney are plate-shaped. Sparks usually occur shortly after travel and 10 to 15 days after travel, and the flame duration varies from half an hour to three hours. During the day it is not noticeable because of the light, but at night it is very shocking. This type of sparkle has a large bright spot, is black and red, and lasts a long time. Ashes and solid particles of different shapes come out of the chimney with the spark. They often fall onto the deck and continue to burn. which can easily cause fires. Generally speaking, in the exhaust system, there is little fire in the pipeline section from the compressor outlet to the exhaust gas boiler inlet, and there is no not much soot on the superheated steam coil of the exhaust gas boiler. However, heating fins are often founddense ffage on the saturated steam coils and numerous solid deposits on the funnel-shaped parts of the exhaust gas boilers. These deposits are the main source of sparks.
Here are the reasons for chimney fires from gasoline generators. I hope this information can be useful to you. Below we will focus on preventive measures and solutions:
Gasoline Generator Set Chimney Fire Preventive Measures:
1. Maintain combustion in the cylinder of the gasoline engine in good condition
2. Strengthen monitoring of the combustion process of each cylinder; detect abnormal conditions in time;
3. Strengthen the management of exhaust gas boilers to maintain good combustion effects;
4. Put suitable carbon remover and other chemicals into the tailpipe or exhaust; regular gas boilernt, in order to prevent scale and clean the system, carbon deposits on the pipe wall can be softened, removed and even burned after lowering the ignition point
5. the tanker, the chimney is equipped with a sprinkler fire extinguishing device.
Emergency treatment for gasoline generator chimney fire
1. If the first type of spark occurs, immediately reduce the load on the gasoline engine or slowly stop it, find the cause and eliminate it. the fault before continuing. Use it, then increase it to the required load once the smoke evacuation is normal.
2 If the second and third types of sparks appear, they must be allowed to continue “spraying”. if the environment permits, so that the exhaust gas blows and burns the oily deposits in the system as much as possible, but the maintenance management work andfire prevention of gasoline engine and exhaust gas boiler should be strengthened;
3. In addition to excessive fire, individual cylinders or local exhaust pipes must be reduced to overheat. When the gear is cut off, the gasoline engine should continue to operate at a higher load as much as possible;
4. Do not use fire extinguishing equipment lightly, especially CO2 fire extinguishing equipment, to prevent high temperature metal from exploding due to a sharp drop in temperature.
References:
I hope this is helpful!
Common faults of gasoline generators are as follows:
(1) Stator fault:
a. Short circuit between phases of the stator winding.
b. Short circuit between turns of the stator winding.
c. The stator winding is single-phase grounded.
(2) Rotor winding fault:
a. The rotor winding is grounded at two points.
b. The rotor winding is grounded at one point.
c. The rotor loses its excitation.
(3) Other failures:
a. The generator catches fire.
b. The generator turns into a motor to operate.
c. The generator oscillates violently or loses synchronization.