How to Select Matching Diesel Generator for Asphalt Mixing Equipment

According to CCTV, since September 2021, the phenomenon of "power cut" in China has spread to more than 10 provinces including Heilongjiang, Jilin, Liaoning, Guangdong and Jiangsu. In order to ensure the normal operation of asphalt mixing equipment, users around the country have taken measures to configure diesel generator equipment.

The diesel generator is a power machine that uses the diesel engine as the prime mover to drive the generator to generate electricity. It is also the key equipment to maintain the power supply of the asphalt mixing plant during the power limit period. In addition, for asphalt mixing plants built outside the city walls and serving highway construction projects, diesel generators can be selected as the power supply to meet the needs of mobile construction and save the cost of purchasing and erecting transformers and lines.

Dingbo Power recommends that users select matching diesel generators according to the installed power and operating power of different types of asphalt mixing plants. 

When selecting the generator, pay attention to distinguish the main power of the generator (the maximum power that the generator can operate continuously within 24 hours) and the standby power (within 12 hours, one hour can overload 10% on the basis of the main power). The continuous operation output power of common diesel generators is generally 0.9 times of the rated power.

1. Preparation before starting diesel generator.

Before starting the diesel generator, it is necessary to check whether the cooling water or antifreeze in the diesel engine  water tank is sufficient, and fill it up if it is insufficient. Pull out the oil scale and check the lubricating oil. If it is missing, add it to the specified "static full" scale line. Then carefully check the relevant parts and remove the fault in time before starting the machine.

Before starting the asphalt mixing equipment, make sure that the main power switch of the control cabinet in the container control room is closed. If it is found that the main power switch of the control cabinet is turned on, it must be turned off in time to prevent the initial voltage and current of the diesel generator from being unstable after starting and damaging the electrical parts in the control cabinet.

2. It is forbidden to start the diesel generator with load.

Before starting the diesel generator, ensure that the output air switch of the generator is closed. After starting the diesel engine of ordinary generator set, it needs to run at idle speed for 3-5 minutes (about 700 rpm); The temperature is low in winter, so the idling time should be extended for a few minutes. After starting the diesel engine, first observe whether the oil pressure is normal (must be above 0.2 MPa) and whether there is oil leakage, water leakage and other phenomena. If any abnormality is found, stop the machine immediately for maintenance; Otherwise, increase the speed to the rated speed of 1500 rpm. At this time, the generator displays a frequency of 50 Hz and a voltage of 400 V, then the output air switch can be closed and put into use. The generator set  is not allowed to operate without load for a long time, because it will make the diesel fuel injected from the diesel engine nozzle not completely burn, and the resulting carbon deposit will cause the valve and piston ring to leak. If it is an automatic generator set, it does not need to run at idle speed, because the automatic generator set is generally equipped with a water heater to keep the diesel engine cylinder at about 45 ℃. After the diesel engine is started, it can normally power on within 8-15 seconds.

After confirming that the generator is powered on, turn on the main power supply of the NSO control cabinet of the asphalt mixing equipment. After ensuring that the input voltage is stable, turn on the main power supply of other container control cabinets.

3. Observe the operation status of diesel generator.

When the diesel generator is working, a special person should be on duty to pay attention to a series of possible faults, especially the changes of important factors such as oil pressure, water temperature, oil temperature, voltage and frequency. In addition, sufficient diesel fuel should be prepared, because if the fuel is interrupted during operation, it may cause a load shutdown, resulting in damage to the generator excitation control system and related components.

When the asphalt mixing equipment is powered by a generator, pay attention to the voltage change of the NSO control cabinet. If the voltage fluctuation is large, check the generator in time to ensure stable transmission voltage and avoid damage to the electrical equipment of asphalt mixing equipment.

4. It is forbidden to stop the diesel generator with load.

Before each shutdown, the load must be cut off gradually, then the output air switch of the generator set must be closed, the diesel engine should be slowed down to idle speed, and the engine should be operated for 3-5 minutes before shutdown.

Before the asphalt mixing equipment is shut down, turn off the main power supply of the control computer, UPS and control cabinet according to the operation process. The generator can only be considered to be shut down on the premise that all parts of the asphalt mixing equipment are shut down and the power supply is cut off.

The above is Dingbo Power's introduction to how to select a matching diesel generator for asphalt mixing equipment. If you want to know more about diesel generators, please contact us via email: dingbo@dieselgeneratortech.com.