How to choose a suitable diesel generator for use in plateau areas?
The normal altitude of common diesel generator set is below 1000 meters However, China has a vast territory. The altitude of many places is much higher than 1000 meters, and some places even reach more than 1450 meters In this case, China Leton power shares the following items that should be paid attention to when purchasing diesel:
The output current of the generator set will change with the change of altitude. As the altitude increases, the power of the generator set, i.e. the output current, decreases and the fuel consumption rate increases. This effect also affects the electrical performance indicators to varying degrees.
The frequency of generator set is determined by its own structure, and the change of frequency is directly proportional to the speed of diesel engine. As the governor of the diesel engine is a mechanical centrifugal type, its working performance is not affected by the change of altitude, so the change degree of steady-state frequency adjustment rate should be the same as that in low altitude areas.
The instantaneous change of load will cause the instantaneous change of diesel engine torque, and the output power of diesel engine will not change instantaneously. Generally speaking, the two indicators of instantaneous voltage and instantaneous speed are not affected by altitude, but for supercharged diesel generator sets, the response speed of diesel engine speed is affected by the lag of supercharger response speed, and these two indicators are increased.
According to the analysis and test, it is proved that the power of diesel generator unit decreases, the fuel consumption rate increases and the heat load increases with the increase of altitude, and the performance changes are very serious.
After implementing the complete set of technical measures for boosting and intercooling power recovery for plateau adaptability, the technical performance of the diesel generator set can be restored to the original factory value at an altitude of 4000m. The countermeasures are completely effective and feasible.
In addition, for the use of diesel generator sets in high altitude areas, we propose the following solutions:
Power recovery supercharging Technology：
Power recovery supercharging mainly refers to the supercharging measures taken for the non supercharged diesel engine when the plateau power drops. It increases the charge density of the cylinder through supercharged air supply, so as to improve the excess air coefficient, achieve the full combustion of the fuel in the cylinder and restore the average effective pressure, so as to restore its power to the low altitude calibration level of the original engine. During this period, its fuel supply remains unchanged. Therefore, good supercharging matching is the most important technical key to the performance recovery of generator sets.
Intercooling measures
After the inlet air is pressurized, its temperature increases with the pressure, which affects the inlet air density and power recovery, and causes a sharp increase in heat load and exhaust temperature, further affecting the reliability. The intermediate cooling device is used to cool the supercharged intake air, which is conducive to reducing the heat load and further improving the power. Its cooperation with the supercharging measures is a key link to improve the power and reliability.
Heat balance control
After boosting and restoring power, the original cooling system can no longer meet the requirements. The reason is that in the plateau environment, the air density decreases and the boiling point of cooling water decreases. If water cooling measures are taken, new heat sources will be added. Therefore, it is necessary to readjust and select appropriate parameters of water tank and fan to reasonably control the heat balance of diesel engine.
Pressurized air filtration system
When the diesel engine is pressurized, the air supply will increase. Especially for the characteristics of high sand and dust on the plateau, the air filter is required to have the characteristics of high efficiency, small resistance, large flow, long service life, small volume, light weight, low cost and easy maintenance.
Plateau cold start
Low temperature starting conditions in plateau are severe. Although the extreme temperature within 4000m above sea level is not very low (-30 ℃), the starting condition is poor due to low air pressure, insufficient compression end point pressure and temperature during starting, and the blocking effect of supercharging device on starting air intake. However, for the unit, the advantage is that the starting load is relatively low, which can be loaded after the temperature rises to an appropriate condition after starting. According to years of low-temperature starting test and research, preheating starting and low-temperature battery combination measures are considered.
Pressurized lubrication system
The supercharger is a high-temperature, high-speed rotating component with a speed of up to 105r/min. Cooling and lubrication are extremely important. Its oil needs special supercharged oil and is also suitable for the diesel engine system. The test shows that the power of diesel generator sets decreases, the fuel consumption rate increases and the heat load increases with the increase of altitude, and the performance changes seriously.
After implementing the complete set of technical measures for plateau adaptability such as boosting and intercooling power recovery, the technical performance of the diesel generator set can be restored to the original factory value at an altitude of 4000m. The countermeasures are completely effective and feasible.
Only by correctly understanding the harmfulness of the impact of high altitude areas on the power of diesel engines, can we correctly and reasonably choose diesel generator sets suitable for our own use, so as to avoid unnecessary waste.
The above contents are provided by China Leton power generator.
sales@letonpower.com
Post time: Jun-27-2022
