Russian gas buses – all the details

The main problem in the development of Russian natural gas road transport is the lack of a developed network of gas filling stations (CNG filling stations). On the other hand, the owners of existing gas filling stations say that car factories produce few cars that run on methane and that CNG filling stations are therefore inactive. It turns out the classic problem – which comes first, the egg or the chicken? Under such circumstances, the number of filling stations and the number of vehicles with LPG will increase in approximately the same proportions as today.

More about this and more read on the website of the magazine “Reis”

How many CNG stations in Russia?

Roadtrains in Russia are forced to travel along the so-called “gas corridors” and build routes of a thousand kilometers so that they have a fuel reserve. In fact, they drive from one gas column to another. Now there are about 540 methane gas stations in the country, they are located in almost every regional center, as well as in most of the largest regional cities. And here arises a slightly different, more positive situation for gas balloon vehicles operating on a short arm. These are the chassis of trucks with various utility superstructures, vehicles working on construction sites, delivery “medium duty trucks” for shopping malls and of course city and city buses.

This number of methane CNG filling stations is very small for Russia, but there are even fewer gas filling stations for refueling cars with liquefied natural gas (LNG/LNG). There are only sixteen. In Moscow, in Kolomna, Moscow region, two in the Leningrad region: in Kingisepp and Peterhof, built in Soviet times. Another one opened recently for liquid methane in Sushary. To the west, there is a cryoCNG station in Kaliningrad. CNG filling stations for liquefied natural gas were opened in the Tver region, in the Konakovo region, in the Tula region, in the Venevsky region. In the east – in Naberezhnye Chelny, Ufa, Chelyabinsk, Satka and Kopeysk of the Chelyabinsk region, as well as in the Kaslinsky district, in Pervouralsk and the city of Sukhoi Log in the Sverdlovsk region.

Is it profitable to continue to give gas?

There are two main positive factors in running vehicles on methane. The first is that natural gas is almost three times cheaper than gasoline or diesel: average prices fluctuate in the range of 14-16 rubles per cubic meter of compressed methane, while the cost of gasoline is at least 45 rubles per liter. The second is that gas cannot be stolen… In cities, these two factors must be supplemented with a third: the environmental friendliness of this type of motor fuel. And there is a fourth: government subsidies for the purchase of gas-powered vehicles. If we talk about LIAZs, the subsidy for the purchase of an LNG / LNG bus is 2.8 million rubles, while for a bus running on compressed natural gas, the subsidy is 960 thousand rubles. At the same time, keep in mind that the ticket price for a passenger remains the same as on a bus with a diesel engine.

Yaroslavl gas engines

Two Russian bus factories, Likinsky and Pavlovsky, are most actively involved in the production of gas balloon buses. First of all, this is made possible by the fact that Yaroslavl diesel engines of the YaMZ-530 series, converted to run on natural gas, are installed in buses. These engines have been produced since the fall of 2016. YaMZ-534 CNG and YaMZ-536 CNG exist in various modifications, both in power settings and in adapting to different vehicles. The main consumers of gas engines of the YaMZ-530 family are Gorky Automobile Plant, PAZ, LIAZ, AZ Ural and Kurgan Bus Plant (KAvZ). The power range of these two engines runs from 150 to 312 hp. from. The “four” has three versions and two settings: YaMZ-53414 has 170 horsepower. from. and 590 Nm at 1200–1600 rpm, YaMZ-53424 and YaMZ-53444 have 150 hp. s., torque 493 Nm at the same speed. The “sixes” also have three versions: YaMZ-53604, YaMZ-53624 and YaMZ-53644. The most powerful is the first engine, 312 hp. from. and 1220Nm. The second setting is 285 horsepower. from. and 1130 Nm, the third has 258 hp. from. and 1080Nm. The amount of torque on a gas engine relative to a diesel engine does not change. Therefore, it is not necessary to adjust the transmission numbers of the car and in particular the main gear, that is, the drive shaft gearbox.

The YaMZ-536 diesel engine has a power range from 240 to 330 hp. from.

The YaMZ-536 diesel engine has a power range from 240 to 330 hp. from.

Russian gas buses - all the detailsThis is a YaMZ-536 gas engine with a capacity of 285 liters. from. with torque 1130 Nm

This is a YaMZ-536 gas engine with a capacity of 285 liters. from. with torque 1130 Nm

The gas versions of the YaMZ‑530 engines have completely switched to the Otto cycle: they have spark plugs and ignition coils, even a throttle. The compression ratio is not 16-17 units, as is usual with a turbo diesel engine, but only 12. To do this, they changed the combustion chamber in the pistons. Recall that methane or propane-butane has an octane number greater than 100, that is, the compression ratio is even higher than for 98th gasoline. Aluminum alloy for pistons is used more heat resistant than for diesel, so it is alloyed with copper and nickel. In addition, the pistons of the gas engine are equipped with a special channel for forced oil cooling. Such “cunning” pistons were mastered by the Kostroma “Motordetal” with the help of licenses from the Kolbenschmidt concern.

Compared to diesel versions, YaMZ-530 gas engines have a unification of about 85 percent. So there are no special problems with spare parts. The declared resource of diesel “fours” is at least 700 thousand kilometers, for “sixes” – more than 900 thousand. Gas engines must have the same mileage before overhaul. The frequency of oil change for gas YaMZ is 15,000 km. The main requirement for gas engine oil is low ash content, less than 1%. The API code must be at least CI4.

On the left – the engine compartment of the diesel LIAZ, on the right – the compartment of the LIAZ LNG, running on liquid methane. The biggest changes are on the right side of the compartment where the gas reducers and evaporators are installed. And behind the wall is the cryotank itself:

Russian gas buses - all the details

Russian gas buses - all the details

Where to place cylinders for compressed or liquid methane?

Usually for a flatbed trailer or van they are placed on the chassis on the sides of the frame beams and in the rear overhang. On a truck tractor, a space for cylinders can also be allocated behind the cab. For the bus, there are only two options for placing cylinders: either under the “skirt” of the body, or on the roof. On LIAZ-5292.67 CNG and PAZ “Vector Next 8.8” CNG cylinders are installed on the roof in front of the body. From the side, the cars look “hunchback”. “Type 3” cylinders are used, ie no steel “Type 1” and no fiberglass with a steel insert “Type 2”. “Type 3” metal-composite cylinders with an aluminum insert reinforced with basalt fiber braiding impregnated with epoxy resin. Cylinders “type 3” are lighter, designed for a pressure of 200-250 bar. In terms of volume, they at least try to ensure the range of the bus from 400 to 600 kilometers.

Usually each cylinder has its own flow valve. It can be blocked, which is convenient for repair or maintenance. And there is a common main valve – the working day of the driver of a gas balloon car begins and ends with it.

About where the fuel equipment was developed and manufactured, as well as the technical details of the bus LIAZ-529267-72-30 – on the next page.

Source: Z R


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