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Using Rules of Weichai Natural Gas Engine

2014/1/13 0:00:00


I. the profile for fuel gas electric control section of Weichai natural gas engine
The Weichai natural gas engine makes the adaptation of pressure-boosted intercooled electric control engine which is combined with fuel gas electric control system additionally on the basis of Weichai diesel engine.
structural drawing of external fuel gas electric control system
1. fuel gas system fittings
CNG engine: gas cylinder---overcurrent protection device---high-pressure filter---high-pressure electromagnetic valve--- pressure reducer--- heat exchanger--- thermostat--- injection valve--- mixer
LNG engine--- gas cylinder--- pressure regulator--- filter element---fuel gas pipeline---fuel cutoff valve--- constant pressure regulator --- heat exchanger--- thermostat--- injection valve--- mixer
2.air-inlet system
air filter--- pressure booster-----intercooler----air-inlet pipe----digital throttle
3.Ignition control system
signal generator---- electronic control unit of engine----ignition module----wire---- high tension coil---- high tension wire---- sparking plug
1) rotational speed sensor: The rotational speed sensor is installed on the signal generator, taking the measurement of rotational speed of engine and producing signals.
2)PTP sensor: PTP sensor is installed in front of digital throttle, taking the measurement of air inlet pressure.
3)MAP/MAT sensor: MAP/MAT sensor is installed in front of digital throttle, taking air inlet pressure and temperature.
4)oxygen sensor: oxygen sensor is installed on the exhaust pipe, taking the measurement of oxygen content, sending the related data to ECM and making the revision of mixture ratio for gas and air.
5)gas pressure sensor: gas pressure sensor is installed on injection valve, taking the measurement of gas pressure.
6)gas temperature sensor: gas temperature sensor is installed on injection valve, taking the measurement of gas temperature.
7)water temperature sensor: water temperature sensor is installed on the water-outlet pipe of engine, taking the measurement of water temperature of engine.
II. the matters need attention for driver:
1.to connect the ignition key when starting engine, halting for five seconds and start engine again, ensuring the gas orbit filled with gas.
1.1 Please do not switch the key to “S” gear if the engine is running, or which will cause damages to engine. You can restart the engine only when it is stopped running completely.
1.2 If you fail to start the engine in the first time, you should wait for 30 seconds to start again.
2. the examination after engine after engine started
2.1 You should check the engine oil pressure after starting engine.
When the temperature of engine reaches the standard cooling water temperature, engine oil should meet the engine requirements: 0.1Mpa for engine oil pressure in idle speed, 0.3 Mpa to 0.5 Mpa for engine oil pressure in standard speed. If the engine oil pressure is lower than the standard parameter causing the alarming light flashing or if the pressure is always in the lower limit, you should stop the engine right now and make a check on the vehicle, and you may start the vehicle again if you solve breakdown.
2.2 Check the water temperature after starting engine
2.3 the matters need attention
Do not step on the accelerator abruptly and violently after you starting the engine.
You should stop the vehicle right now if breakdown occurs.
3.vehicle operation
The correct and proper method of driving prolongs the life span of vehicle, promotes economic benefits and exerts a strong influence on the vehicle safety. You should comply with the following principles when you start the engine: you should step on the throttle slowly instead of violent treading.
4. engine shutdown
4.1 The temperature in engine will get higher and higher after you start the engine. At this moment, you should keep the vehicle in idle speed for 3 to 5 minutes instead of shutdown engine immediately. You can shut down the engine after all the parts of vehicle cooling down and switch the ignition switch to “OFF”.
If engine keeps overworking for a long time, it should be in idle speed for a while to cool down water in the engine, and then it can be shut down completely. The engine we use is turbo pressure boost engine, which means the sudden halt of vehicle will lead to the damage of rotor bearing.
4.2 close the gas cylinder and cut off main power switch.