GFS EVO-SP dual fuel retrofit complete solution

The ECU has a sampling frequency of up to 50 times per second and monitors over 25 sensor channels. It first records the benchmark performance curve of the engine in 100% diesel mode (exhaust temperature, vibration, air-fuel ratio, etc. under different loads). Subsequently, in dual fuel mode, the natural gas substitution rate and throttle opening are dynamically adjusted based on real-time load changes to ensure that key parameters always do not exceed the safety boundary of the benchmark curve.

The substitution rate is generally between 50% and 70%, depending on the engine model, load factor, and natural gas calorific value. The system will automatically optimize without manual intervention.

3.2 J1939 Communication and Integration

ECU is compatible with SAE J1939 protocol and can directly read the common rail pressure, fuel injection quantity, speed and other information of the electronically controlled diesel engine. For old mechanical engines, corresponding sensors (such as diesel flow meters and speed sensors) need to be installed to achieve closed-loop control.

3.3 Seamless Switching Logic

The system is equipped with multi-level alarm and shutdown logic:

Pre alarm: Parameters deviate from the normal range but are still controllable, only prompting the operator.

Alarm: Exceeding the safety limit but not immediately dangerous, automatically reducing the gas substitution rate.

Shutdown: In case of serious abnormalities (such as combustible gas leakage, flame detection, overspeed, high vibration, etc.), immediately close the dual solenoid valves and switch to 100% diesel operation without interruption.

The switching process is automatically completed by the ECU, and the output voltage and frequency of the generator will not fluctuate.

Security Design: Multiple Redundancy and Disaster Prevention Protection

Safety is the primary consideration for dual fuel retrofitting. The EVO-SP system has built a rigorous protection system from three levels: mechanical, electrical, and logical.

4.1 Gas valve group redundancy

The gas supply pipeline adopts double normally closed solenoid valves in series, and any valve failure may cause gas cut-off rather than accidental leakage. In addition, manual shut-off valves are provided for use during maintenance. This valve group has passed global mainstream certifications such as UL, UR, CSA, FM, CE, AGA, GOST, etc., meeting the strictest safety standards.

4.2 Combustible Gas and Flame Detection

Install combustible gas detectors and flame detectors around the generator. Once the methane concentration exceeds the standard or an open flame is detected, the ECU immediately performs the following actions:

Switch the engine back to pure diesel mode

Cut off the power supply of the dual solenoid valve

Send alarm signals to building control systems or fire protection systems through external interfaces

4.3 Explosion and mechanical protection

The system is equipped with vibration sensors (knock detection) and exhaust temperature sensors, which can detect detonation, premature ignition, or thermal overload in a timely manner. If a cylinder experiences abnormal high-frequency vibration, the ECU will reduce the gas ratio cylinder by cylinder until detonation is eliminated.

4.4 Electrical Protection

The ECU input power supply has:

Load sudden drop overvoltage protection (withstand>100V instantaneous overvoltage)

Undervoltage lockout (<18V shutdown output)

Reverse connection and dual battery voltage protection

Working temperature range: -40 ℃~+105 ℃

The touch screen panel has a protection level of IP65 (NEMA 4X for the entire machine) and can operate stably in humid and dusty environments.

Technical Specification Quick Reference Table

Key parameters of components

ECU 32-bit microcontroller, J1939 compatible, sampling 50 times/second, 24V power supply, IP56

Touch screen 12.1 "TFT, 1024 × 768, IP65, -20~60 ℃

Mixer 6 "aluminum alloy, 1.5" JIC inlet, -40~105 ℃

Gas valve DN65, 24-28VDC, switch<1 second, IP54

Environmental adaptability storage -40~125 ℃, random vibration 0.3G/Hz (10-2000Hz), impact 40G

Gas pressure 3-7 PSI (0.2-0.5 bar), pipeline natural gas

Substitution rate 50%~70% diesel replacement

Seamless conversion time,<1 second (valve closing time)

Engineering Application: Typical Scenarios and Benefit Analysis

6.1 Applicable Scenarios

Emergency backup power generation: In the case of limited diesel storage tank capacity, connecting to the natural gas pipeline network can extend emergency operation time by several days or even weeks.

Peak shaving power station: Utilizing the low period of natural gas prices to increase substitution rate and reduce marginal cost of power generation.

Island/microgrid: Reduce diesel supply frequency and improve energy self-sufficiency.

Environmentally restricted areas: Reduce NOx and particulate emissions to meet local environmental requirements.

6.2 Economic Benefit Estimation

Taking a 1MW generator set with an annual operation of 1000 hours as an example:

The heat consumption rate of diesel is about 210 g/kWh, and the fuel consumption per 1 MW hour is 210 kg.

The price of diesel is calculated at 6 yuan/kg, with an hourly fuel cost of 1260 yuan.