Gas generator engines: principle of operation, specifications, fuel

2024 Author: Erin Ralphs | [email protected]. Last modified: 2024-02-19 11:42

Gas generator engines have one indisputable plus - renewable fuel that does not undergo pre-treatment. The history of the use of machines with such equipment is quite long. Now they are not as popular as they used to be, but little by little they are returning to service.

Main Features

The gas generator engine has several undeniable positive features. First, the fuel for the device is very cheap. Secondly, during the operation of the device, ash appears, which can be used as fertilizer, for example. Thirdly, the car will not require the installation of powerful chemical batteries.

Gas engines have proven their right to exist for a very long time. Today, their performance, of course, is much inferior to new models running on gasoline. However, for most ordinary motorists, they may well be suitable. The gas generator unit will allow reaching speeds of up to 100 km/h, the approximate maximum mileage will be about 100 km. To increase this parameter, you will have to carryin the back seat additional bags of firewood and periodically manually add "fuel" to the tank.

How the device works

The principle of operation of the gas generator is synthesis gas. This is a process during which combustible gas will be formed when organic material is burned. In order to start such a process, it is necessary to reach the desired temperature. Gas synthesis begins when the indicator reaches 1400 degrees Celsius. Peat, coal briquettes and some other materials can be used as fuel for a gas generator engine. However, as practice has shown, wood is the most common and convenient material for fuel. Although it is worth noting here that firewood has one drawback - a decrease in the charge of the working mixture. As a result, the power of the installation is somewhat reduced.

It may be added that this type of wood-burning engine is usually used with an internal combustion engine already installed.

Technical indicators

If there is a choice, for example, between buying a car with a conventional engine or with a gas generator, then you need to elaborate on the technical data of the second option.

The mass of the engine on the wood is large enough, because of which some of the maneuverability is lost. This disadvantage becomes dangerous if you develop a high speed. For this reason, bringing the car even to 100 km / h is not a very reasonable decision - you have to driveslower. There are some more important technical data of such equipment.

The wood-burning gas engine has a higher compression ratio than truck gasoline engines. As for power, the gas generator, of course, loses to a gasoline engine.

The last difference not in favor of the gas model is the carrying capacity, in which it also loses to a car with a gasoline engine.

It is also important to note here that wood gas has a low energy value when compared to natural gas. A wood-burning car will inevitably lose its dynamic properties, which should also be taken into account by the driver of such a vehicle.

Some people prefer to install a volumetric gas generator on a trailer, rather than on the car itself. In this case, it will not be possible to quickly accelerate, and it will not work out much to maneuver. The trailer will be a kind of limiter.

Pros of gas generators

If we talk about the advantages of cars with gas generator engines, then the possibility of using renewable fuels without pre-treatment immediately comes to the fore. For example, to convert biomass into a usable fuel, say ethanol or biodiesel, energy is consumed, including CO2 energy. Moreover, in some cases, more energy is spent for the transformation than the original substance contains. As for the wood-burning gas engine, it does not require energy to produce its fuel. Unless you need to cut and chop the wood itself for ease of loading.

If we compare a car with a gas generator and an electric car, we can single out the following advantage: no need for a powerful chemical source of energy - a battery. The disadvantage of such chemical batteries is that they have the property of self-discharge, and therefore, before operating such a car, you must not forget to charge it. If we talk about devices that generate gas, then they themselves are "natural" batteries.

When properly assembled and operated in a vehicle, a gas generator will be significantly less polluting than any gasoline or diesel engine. Of course, when compared with an electric car, which does not emit any emissions into the atmosphere, the gas generator loses. However, charging electric cars requires a lot of energy, and it is still produced by traditional methods that heavily pollute the air.

Cons of gas generators

Despite the certain advantages of such installations, their installation is still a very individual solution and not the most optimal. The gas generating plant itself takes up a lot of space, and it weighs several hundred kilograms. At the same time, all this bulky structure will have to be transported with you. The large dimensions of the gas installation are due to the fact that wood gas is characterized by a low specific energy coefficient. For example, we can compare the specific energy value of wood gas, which is 5.7MJ/kg, with the energy released by burning gasoline being 44 MJ/kg, or 56 MJ/kg from burning natural gas.

Car running on a gas generator

When operating such a gas engine, it will not be possible to achieve the speed and acceleration possible when using a gasoline counterpart. The problem lies in the composition of wood gas. It is 50% nitrogen, 20% carbon monoxide; the remaining 18% is hydrogen, 8% is carbon dioxide, 4% is methane. Nitrogen, which occupies half the specific mass of the gas, is not at all capable of supporting combustion, and carbon-based compounds reduce combustion efficiency. A large amount of nitrogen reduces the overall power of such a generator by about 30-50 percent. Carbon reduces the rate of combustion of the gas, due to which it is not possible to achieve high speeds. As a consequence, the dynamic performance of the car decreases.

Use of gas generator

There is one more small problem of gas-powered vehicles, which is related specifically to their use, should be noted. It is connected with the fact that the installation needs to reach the operating temperature, and only then you can go. The time required to reach this temperature is approximately 10 minutes. In addition, before the next loading of firewood, it is necessary to clean the ashes each time with a spatula. Another maintenance problem is tar formation. Now it is no longer as sharp as before, but you still have to clean the filters from dirt. All this leads to the need for frequent maintenance.generator.

If we talk in general about the care of such a device, then we can say this: there is a lot of trouble with maintenance, which is completely absent in gasoline engines.

Generator set for ZIS-21

As already mentioned, the basic principle of the generator is the transformation of solid fuel into gas entering the cylinders. The gas generator ZIS-21 mainly ran on fuels such as oak and birch. Sometimes a brown type of coal was used, as it was the least hygroscopic and gave the most gas at the outlet.

As for the design of a typical gas generator for the ZIS-21, it consisted of the following elements: the gas generator itself, a cooler-purifier, a fine cleaner, a mixer and an electric fan.

Work of installation on VMS

At the top of the generator was a bunker into which solid fuel was loaded. The firebox was located directly under the bunker itself. This is where wood was burned. As the old fuel burnt out, an "automatic supply" of new wood was carried out. In fact, she simply fell from the bunker into the firebox under her own weight when space was freed. The gas generating unit itself was located on the left side of the car.

In the same firebox, the formation of carbon monoxide also occurred due to the pulling of air through the burning fuel. The suction of oxygen occurred either due to rarefaction in the cylinders, or due to the operation of an electricfan. These methods were forced, but there were installations with natural air draft. However, in this case, it could take up to an hour to prepare for the launch.

Under the firebox there was an ash pan, as in any ordinary stove. The products of combustion accumulated here. Every 80-100 km it was necessary to clean it from ash. However, it is fair to say here that this fact only caused problems for the driver of the vehicle.

Gas path in installation and cleaning

All the gas obtained during the combustion of firewood entered the shirt that surrounded the bunker. Thus, heating of this compartment was achieved. This was necessary to pre-dry all the wood prepared for burning. Further, it should be noted that after leaving the generator, the gas had a temperature of approximately 110-140 degrees. Therefore, it had to pass through the sections of the radiator. There, he not only lowered his temperature, but was also cleansed of heavy chemical impurities along the way.

As for the cleanup, it went like this. Sections of the cleaner-heat exchanger were internal perforated pipes. This design was similar to current exhaust systems. The hot gas expanded greatly, due to which it lost its flow velocity. Passing through the labyrinths of pipes, he slowed down even more. Impurities were screened out from it and remained on the inner walls of the outer tubes of the heat exchangers. This was followed by a fine cleaner.

Conclusion

At the end, we can sum up the following. The characteristics of gas generator engines are rather weak when compared with gasoline engines. The installation has some advantages, but it is quite inconvenient to use, requires constant and careful maintenance. In addition, it does not allow you to develop high speed and reduces maneuverability. For these reasons, cars with such gas generators are not practically very popular.