ООО «Техэкспо»
Selected city:
St. Petersburg
Promyshlennaya St., 19R
Phone number and open hours:
+7 (812) 602-52-94
Mon-Sun 7am – 8pm
Call to order:
8 (800) 550-83-94 Request a call back
Call to order: 8 (800) 550-83-94

Dual-fueled (gas diesel) gensets

Techexpo LLC offers dual-fueled gensets with a unit capacity from 1 to 2 MW based on Perkins and Cummins engines. The DG is completed with a GTI Bi-Fuel special dual-fueled regulating system developed by Altronic for diesel engines on fuel mixture with a gas content of up to 70%. The system switches fuel modes without stopping the engine, switching of gas/diesel modes is automatic at a constant rotation speed and output power of the engine.

When the load thresholds are reached, it automatically switches to 100% diesel mode. For projects with significant load fluctuations, a STEPCON discrete control version is used, which changes the fuel ratio based on a table load function. The direct economic effect is provided by the replacement of the share of diesel fuel with a gas containing methane..

  • The price of the GTI Altronic dual-fuel system for a 1 MW engine is about 3 million rubles.

Power supply projects at gas diesel stations

Description of work technology

Gas is delivered to the space between the air filter housing and the turbocharger at a pressure approximately equal to atmospheric pressure. The patented mixer allows preparing a homogeneous gas-air mixture with minimal airflow limitation. After leaving the mixer, the gas-air mixture is compressed in the turbocharger and distributed through the intake manifold to the engine cylinders. The lean gas-air mixture is then compressed in the cylinder during the compression stroke and ignited at the moment of diesel fuel injection. The lean composition of the gas-air mixture guarantees the impossibility of pre-ignition.

The amount of gas entering the engine depends on the load and changes with airflow changes. The system changes the gas supply according to the change in the vacuum level in the engine. In this way, the system replenishes the engine's need for fuel with a change in the load without affecting the operation of the original control system.

Принципы работы - двухтопливные (газодизельные) электростанции   

The standard delivery package of a dual-fuel system includes a throttle device for manual adjustment of the fuel ratio. The standard engine management system regulates the diesel fuel supply in both diesel and dual-fuel modes.

The dual fuel system controller is designed to monitor various engine and system parameters such as manifold air pressure and temperature, exhaust gas temperature, inlet vacuum, gas pressure and engine vibration.

Based on the information received, the controller activates or deactivates dual-fuel mode depending on engine performance, load, ambient temperature, vibration level or gas pressure.

The controller can transfer information to the engine remote monitoring system via RS-232/RS-485 (ASCII or ModBus RTU protocol).

Engine performance in dual-fuel mode is generally maintained at the same level as in diesel mode. The amount of heat removed by the cooling system and exhaust gases remains within the normal range. Engine response to load increase or decrease in dual-fuel operation is generally the same or better than in diesel operation due to the unique design of the dual-fuel system and the combustion characteristics of the air-gas mixture. Accordingly, the ability of the engine to receive load (with a sudden surge) is maintained at the same level or improved.


GTI Altronic bi-fuel system: installation and operation manual

Installation & Operating Manual GTI Altronic Bi-Fuel System

Bi-Fuel package

GTI series Engine capacity rate Engine type 
Gas pipeline
Air-gas mixer Serial #


1200-3000 kW V-type, general cycle
DN80 / 3" NPT
2 x 7"


4 x 6"


4 x 7"


V-type, 2-cycle
DN80 / 3" NPT 2 x 7"


4 x 6"


4 x 7"


V- type, 4 cycle
DN80 / 3" NPT 2 x 7"


4 x 6"


4 x 7"


The main components of gas and diesel system

Gas-air mixer

For optimal mixing of gas and air entering the engine, a patented gas-air mixer is used. The special design, which has no moving parts, promotes thorough mixing and ensures that a sufficient amount of gas-air mixture enters the engine while maintaining the pre-set engine performance. The production uses aerospace technology, CNC machining, and modern welding techniques. The mixer has no moving parts and is maintenance-free after installation.

Throttling device

A part of the dual-fuel system is an adjustable element installed in front of the gas-air mixer. The throttle device is a special component of the system that doses the maximum gas supply to the engine at a given load and inlet vacuum. The throttle device together with a gas-air mixer and a zero-pressure regulator ensures that the required amount of gas is supplied to the engine. The throttle is CNC machined and maintenance-free.

Gas line

The gas line includes a 50-micron filter, an electronic solenoid valve actuated in case of danger or to shut down the system, and a variable flow zero-pressure regulator (reduces the operating gas pressure of 21 ± 7 kPa to a pressure that is almost equal to atmospheric pressure). The design implements an “as required" control circuit when the gas flow depends on the air flow entering the engine. When the load changes, the amount of air entering the engine changes, which automatically causes a change in the flow of gas entering the gas-air mixer.

Control system

The control system is developed based on Altronic controllers specially for GTI Bi-Fuel dual-fuel system. Based on temperature and pressure monitoring in several points the system returns the engine to work in 100% diesel mode in case of deviation of parameters values from the set limits. The hour meter takes into account the running time in dual-fuel mode. The controller displays alarm messages and stores records of the last 100 events.

Video: mixer, throttling devices, lines

Discrete control (STEPCON)

The STEPCON option is the extension of the GTI Bi-Fuel basic fuel-fuel system. This is a fuel manifold, power transducer and dedicated control panel (optimizes gas/diesel ratios in response to fast load changes). The design solution requires no modification to the engine, controls or sensors and uses all the same basic safety systems to protect the engine. To determine the motor load, the STEPCON option is equipped with a measuring power converter; a controlled fuel manifold is installed directly at the outlet of the gas line. Three discrete solenoid fuel valves are installed in the fuel manifold parallel to the standard throttling device. The effective flow area of each valve is selected during system commissioning. The standard commissioning procedure is carried out in the load range where the least displacement is expected. All three solenoids are closed; the initial (smallest) displacement is set by the position of the manual throttle device. The commissioning procedure is then repeated for the second, third, fourth discrete levels, each time setting the replacement percentage for the corresponding load range by changing the flow area of each solenoid valve.

The adapted software is used to model various combinations of the state of the three solenoid valves in the fuel manifold. Thus, a control law is formed that takes into account the engine's tolerance to gaseous fuel with a change in load and provides optimal replacement in a wide range. A tabular relationship is used by the GTI control panel to quickly shift to a preferred valve combination during load changes to maximize the benefits of the dual-fuel operation.

Diesel generator sets: