How To Start Diesel Generator Set In Low Temperature Environment

The normal startup of diesel generator sets requires certain environmental conditions. When the environment does not comply with the standard provisions, it is easy to bring risks and difficulties to the safety production guarantee of power supply. In order to enable the diesel generator sets to start smoothly in low temperature environment and ensure the safe production of power supply in an orderly manner, Jiangsu Starlight Electricity Equipments Co.,Ltd. has sorted out some reasons and treatment methods for the difficulty in starting diesel generator sets in low temperature environment, I hope it will be helpful to you.

Cause analysis of difficulty in starting diesel generator set at low temperature.

1. Temperature reasons. The low temperature in winter causes a significant decrease in the intake temperature of diesel engines, resulting in the compressed air temperature in the combustion chamber not reaching the ignition temperature during ignition. Generally, diesel engines require a cylinder temperature of over 400 ℃ after compression, with a minimum temperature not lower than 350 ℃. At the end of compression, the compressed air in the cylinder cannot reach the pressure and temperature required for diesel combustion, resulting in difficulty in starting the diesel engine.

2. Diesel reasons. As the external temperature decreases, the viscosity and density of diesel fuel increase, surface tension increases, and flowability deteriorates. Even the gradual precipitation of paraffin can cause blockage of the diesel filter or blockage of the oil circuit, which is not conducive to fuel atomization and combustion, leading to difficulty in starting the diesel engine. According to measurements, when the temperature drops from 40 ℃ to -10 ℃, the viscosity of diesel increases by 83% and the density increases by 8%. This results in poor fluidity of diesel fuel, poor atomization, and prolonged ignition lag.

3. Oil reasons. The higher the viscosity level of the oil used in a diesel engine, the greater the starting resistance and the corresponding required power. Oil with poor low-temperature performance exhibits high viscosity and even condensation in low-temperature environments, which increases the rotational resistance torque of the crankshaft and reduces the starting speed, making it difficult for the diesel engine to start.

4. Battery reasons. The optimal working temperature of a battery is around 20 ℃ -25 ℃. When the ambient temperature is below 15 ℃, its discharge capacity decreases. For every 1 ℃ decrease in temperature, its capacity decreases by 1%. And as the temperature decreases, the electrolyte viscosity of the battery increases, the permeability to the electrode plate decreases, and the internal resistance increases. In order to prevent the electrolyte from freezing, the lower the external temperature, the greater the need to increase the electrolyte density. The diesel engine battery pack needs to have high current discharge capacity, but low air temperature reduces the output power of the battery and cannot reach the minimum starting speed, resulting in difficulty in starting the diesel engine.

5. Reason for antifreeze. Antifreeze is an indispensable heat dissipation medium for diesel generator set operation. Its role is to cool the engine and prevent the cooling water tank from freezing and cracking in winter. If an antifreeze with a suitable freezing point cannot be selected, it will cause the water tank to freeze at low temperatures, affecting the circulation of the cooling system and making it difficult to start the diesel engine.

Analysis of countermeasures to improve the starting difficulty of diesel generator set.

1. Install the water jacket heater. The jacket heater is a device to preheat the cooling water and engine oil of the diesel generator, so that the engine body can reach a temperature suitable for operation. It is a necessary supporting equipment for the diesel generator set under low temperature working environment. Part of the cooling water inside the machine body is heated by electric heating, and thermal cycling is carried out based on the density difference principle between hot and cold water. The lubricating oil on the cylinder body and mechanism firmware of the unit is then preheated to achieve the purpose of warming up and improving lubrication conditions. When the working environment temperature of the oil engine is below 0 ℃, the water jacket heater should be turned on to maintain the water temperature at around 30 ℃.

2. Reasonable selection of diesel fuel. In areas with low temperatures in winter, high-quality diesel with low pour point and good flow performance should be selected. The principle for selecting diesel is that the pour point is about 5 ℃ lower than the lowest temperature with a risk rate of 10%. For example, if the lowest temperature in a certain region with a risk rate of 10% is -5 ℃, it is necessary to choose diesel with a pour point not higher than -10 ℃, that is, -10 diesel. For example, the Jianghuai region uses -10 diesel, which is suitable for use in winter.

3. Reasonably select engine oil. The selection of oil with appropriate viscosity should be based on the characteristics of diesel engines and the local climate. In low temperature areas in winter, it is recommended to use lubricating oil with excellent low-temperature performance or professional antifreeze oil. This type of oil has low viscosity, good lubrication performance, and low starting resistance, which can effectively improve the starting performance of diesel engines under low temperature conditions. For example, the Jianghuai region uses multi-stage oil with a viscosity grade of SAE15W-40, which is suitable for use in winter.

4. Reasonable selection of batteries. In areas with low temperatures in winter, if conditions permit, it is advisable to choose specialized battery packs with excellent low-temperature performance. If a regular battery pack is used, monitoring and maintenance of the battery pack should be strengthened to ensure that the battery charges normally under low temperature conditions and has sufficient high current output, thereby extending the service life of the battery pack.

5. Increase maintenance frequency. The frequency of maintenance and inspection of diesel generator set equipment shall be increased during the winter cold weather with severe snow and ice. Replace the diesel filter, oil filter, air filter and other common components in advance, and replace the oil and cooling water antifreeze. Keep all parts of the unit clean and dry, with good circuit contact, to ensure that the oil engine is working in its optimal state.

6. Oil engine start test. During the winter cold weather of snow and ice, special diesel generator set startup test shall be added to timely check the potential safety hazards of the unit, so as to ensure that the diesel generator set can be started in time to ensure the power supply of equipment in case of the interruption of two-way mains power.

7. Pay attention to the insulation of the computer room. Pay attention to closing the doors and windows of the oil room in winter. If conditions permit, electric louvers should be installed to facilitate the insulation of the oil room. During ice and snow weather, special inspections and patrols should be carried out to prevent water seepage or freezing of the computer room doors, windows, roofs, cable trenches, etc.

Although temperatures have rebounded in most regions of the country, low temperatures in some areas will continue for a long time, and some may even be at low temperatures year-round. Therefore, users still need to pay attention to the phenomenon of the unit being unable to start due to low temperatures.

Starlight Power was founded in 1974 and is one of the earliest manufacturers of generators and diesel generator sets in China. If you want get more information, please feel free to send email to sales@dieselgeneratortech.com, we will pay highly attention on your question.