Types of steam locomotives

Depending on the utilization of the working medium

(1) single expansion locomotive, once the steam expands in the cylinder, it is discharged into the atmosphere. The locomotive is simple in structure and widely used.

(2) Compound expansion locomotive, steam expands in one or a pair of cylinders (high pressure cylinders) and then enters another or another pair of cylinders (low pressure cylinders), and then expands once before being discharged into the atmosphere. Although this kind of locomotive has high thermal efficiency, its structure is complicated and it is seldom used.

(3) condensing locomotive, the exhaust gas enters the condenser installed at the back of the coal waterwheel and condenses into water, and then it is pumped into the boiler for reuse, and the lost water is supplemented by the water of the coal waterwheel. Locomotive structure is very complicated, and it is mostly used in water-deficient areas. (4) Saturated steam locomotive and superheated steam locomotive, because the superheater for locomotive was created to increase the steam temperature, the efficiency of steam turbine was improved a lot, and the saturated steam locomotive was transformed into superheated steam locomotive.

Classification by cylinder position

According to the cylinder installation position, steam locomotives can be divided into:

(1) locomotive with external cylinders, the cylinders of which are fixed on the outer sides of both sides of the frame, are widely used because of convenient maintenance.

(2) internal cylinder locomotive, the cylinder of the locomotive is fixed on the inside of the frame, and the movable axle is made into a crankshaft, which is inconvenient to maintain and rarely used.

③ For a three-cylinder locomotive, two cylinders are fixed on the outside of the frame, and the third cylinder is fixed in the middle of the frame.

Classification by frame form

Steam locomotives can be divided into:

(1) Plate-beam frame locomotive, which has a plate-beam structure and a light frame, is widely used in European countries.

(2) Rod-beam frame locomotive, whose frame is rod-shaped, is widely used for cutting and forming thick steel plate or cast steel.

According to the composition of the frame and power plant.

As far as its framework and power plant are concerned, steam locomotives can be divided into:

① In conventional locomotives, only one fixed frame constitutes a power unit (including cylinder, moving wheel, connecting rod device and valve device, etc.). ) and support the boiler.

(2) Articulated locomotive, besides a power unit consisting of a fixed frame and supporting the rear half of the boiler, there is also a rotatable frame connected with the rear fixed frame to form another power unit, which can slidably support the front half of the boiler and play the role of a bogie.

Classification by water tank position

According to the installation position of water tank, steam locomotive can be divided into:

(1) Coal-water-wheel locomotives are widely used, and the rear part of them is connected with a coal-water wheel specially used for long-distance running of locomotives.

(2) Water tank locomotive, there is a cuboid water tank or saddle-shaped water tank on both sides of the locomotive boiler, and the coal is stored in the coal tank behind the cab. Another kind of water tank locomotive stores water in the water tank at the lower part of the coal tank. Water tank locomotive has less coal and water. Only used for shunting, short-distance transportation and industrial and mining transportation.

Classification by fuel used

Steam locomotives can be divided into:

(1) coal-fired steam locomotive, which burns bituminous coal in the fire box, is a widely used locomotive.

(2) Oil-fired steam locomotives and atomized boiler oil are burned in the fire box and used in oil-producing areas without coal or places with special requirements.

Classification by prime mover

Steam locomotives can be divided into:

(1) In the past, steam locomotives powered by compound steam engines were simple in structure and widely used. Steam locomotive usually refers to this kind of locomotive.

② A steam locomotive powered by a steam turbine is called a steam turbine locomotive. Turbine speed is high, so it must be equipped with reducer, so there are two kinds of electric drive and mechanical drive. Exhaust gas can be condensed and non-condensed. Because of the complex structure, high cost, high maintenance cost and much higher thermal efficiency than steam locomotives, steam locomotives have not been popularized.