How to choose the power of diesel generator set?
2021-06-21
When purchasing diesel generator set, the comprehensive performance and economic indicators of diesel generator set, the professionalism, geographical location and actual professional level of the supplier, and whether the supplier has after-sales service means, such as rush repair vehicle, special machines and tools, should be fully considered. Then consider whether the power of the selected unit matches the power of the electric load. Generally, it is better to select the unit power based on: rated power of unit x0.8 = power of electric equipment. If there are large and medium motors, 2-5 times of starting current should be considered. If the unit is mainly used to charge the ups, a professional consultation must be made according to the actual situation of UPS, and then the rated power of generator can be determined.
Before selecting the diesel generator set, we should first clarify the relationship between the five powers in the parameters of the diesel generator set, namely apparent power, active power, rated power, maximum power and economic power. Many people will confuse their definitions. Here, I will help you to sort them out for your understanding.
(1) The unit of apparent power is KVA, which is used to express the capacity of transformer and UPS in China.
(2) Active power is 0.8 times of apparent power, the unit is kW, China is used to power generation equipment and electrical equipment.
(3) The rated power of diesel generator set refers to the power that can run continuously for 12 hours.
(4) The maximum power is 1.1 times of the rated power, but only one hour is allowed within 12 hours.
(5) The economic power is 0.75 times of the rated power, which is the output power of the diesel generator set that can run for a long time without time limit. At this power, the fuel consumption is the lowest and the failure rate is the lowest.
When choosing diesel generator set, you can calculate the load you need in advance, and then choose the generator set according to the load.
1. First of all, it is necessary to distinguish the difference between the apparent power and effective power of diesel generator set. The relationship between them is 1kVA = 0.8kw. The power unit of imported unit is generally expressed in KVA, while that of domestic electrical equipment is generally expressed in kW. Therefore, when calculating the power, the KVA should be converted into kW.
2. Secondly, it is necessary to determine the rated power and maximum power of the diesel generator set to be selected.
3. In addition, to determine the power of the generator set is not to simply add the power of all electrical appliances, but also need to consider the starting mode of electrical appliances. The general starting mode is divided into direct starting and step-down starting or frequency conversion starting. The former starting current is about 6 times of the working current, and the instantaneous power will also reach 6 times of the rated power; The starting current of the latter is about 3 times, and the instantaneous power is also 3 times of the rated power. Therefore, when selecting the power of generator set, in addition to the sum of the power of all electrical appliances, the starting power of each electrical appliance should also be considered.
reminder
Generally, 0.8 times of the output power of the diesel generator set is the output power of the actual generator set, which can not only keep the generator set from overload operation, but also ensure the generator set from long-term low load operation, so as to extend the service life of the diesel generator set. In addition, the diesel generator set is a non continuous operation power generation equipment. If it operates continuously for more than 12 hours, its output power will be about 90% lower than the rated power. If users need to use it continuously for a long time, they need to configure the common generator set, that is, the generator set should take into account the power drop of the unit working for a long time.
Before selecting the diesel generator set, we should first clarify the relationship between the five powers in the parameters of the diesel generator set, namely apparent power, active power, rated power, maximum power and economic power. Many people will confuse their definitions. Here, I will help you to sort them out for your understanding.
(1) The unit of apparent power is KVA, which is used to express the capacity of transformer and UPS in China.
(2) Active power is 0.8 times of apparent power, the unit is kW, China is used to power generation equipment and electrical equipment.
(3) The rated power of diesel generator set refers to the power that can run continuously for 12 hours.
(4) The maximum power is 1.1 times of the rated power, but only one hour is allowed within 12 hours.
(5) The economic power is 0.75 times of the rated power, which is the output power of the diesel generator set that can run for a long time without time limit. At this power, the fuel consumption is the lowest and the failure rate is the lowest.
When choosing diesel generator set, you can calculate the load you need in advance, and then choose the generator set according to the load.
1. First of all, it is necessary to distinguish the difference between the apparent power and effective power of diesel generator set. The relationship between them is 1kVA = 0.8kw. The power unit of imported unit is generally expressed in KVA, while that of domestic electrical equipment is generally expressed in kW. Therefore, when calculating the power, the KVA should be converted into kW.
2. Secondly, it is necessary to determine the rated power and maximum power of the diesel generator set to be selected.
3. In addition, to determine the power of the generator set is not to simply add the power of all electrical appliances, but also need to consider the starting mode of electrical appliances. The general starting mode is divided into direct starting and step-down starting or frequency conversion starting. The former starting current is about 6 times of the working current, and the instantaneous power will also reach 6 times of the rated power; The starting current of the latter is about 3 times, and the instantaneous power is also 3 times of the rated power. Therefore, when selecting the power of generator set, in addition to the sum of the power of all electrical appliances, the starting power of each electrical appliance should also be considered.
reminder
Generally, 0.8 times of the output power of the diesel generator set is the output power of the actual generator set, which can not only keep the generator set from overload operation, but also ensure the generator set from long-term low load operation, so as to extend the service life of the diesel generator set. In addition, the diesel generator set is a non continuous operation power generation equipment. If it operates continuously for more than 12 hours, its output power will be about 90% lower than the rated power. If users need to use it continuously for a long time, they need to configure the common generator set, that is, the generator set should take into account the power drop of the unit working for a long time.