Basis for purchasing emergency and common diesel generator sets

As a manufacturer of diesel generator sets, Haixing Power has a say in the purchase of diesel generator sets. There is a big difference in the purchase of emergency diesel generator sets and common generator sets. Let the staff explain in detail the basis for purchasing diesel generator sets.

Emergency diesel generator selection

Emergency diesel generators are mainly used in important places. In the event of an emergency or accidental power outage, the emergency generator set can quickly restore and extend the power supply for a period of time. This type of electrical load is called a primary load. Equipment, instruments and computer systems that have strict requirements on power outage time should be equipped with batteries or UPS in addition to generators.

The work of emergency diesel generators has two characteristics:

The first feature is that for emergency use, the continuous working time is not long, and generally only needs to continue running for a few hours (≤12H);

The second feature is that it is used as a backup. The emergency generator set is usually in a shutdown waiting state. Only when the main power supply is completely interrupted, the emergency diesel generator set will start running to supply the emergency power load. When the main power supply returns to normal, it will switch immediately. downtime.

(1) Determination of emergency diesel generator generator capacity

The calibrated capacity of the emergency diesel generator set is the 12-hour calibrated capacity corrected by the atmosphere. Its capacity should be able to meet the emergency total calculated load, and should be verified based on the generator capacity that can meet the requirements for starting a single capacity motor in the first-level load. Emergency generators generally use three-phase AC synchronous generators with a calibrated output voltage of 400V.

(2) Determination of the number of emergency diesel generator sets

When there are multiple generator sets on standby, generally only one emergency diesel generator set is installed. For reliability reasons, two units can also be connected in parallel for power supply. The number of generator sets for emergency use should generally not exceed 3. When multiple units are selected, the units should try to use complete sets of equipment with the same model, capacity, and similar pressure and speed regulation characteristics. The properties of the fuel used should be consistent to facilitate maintenance and sharing of spare parts. When there are two generating units supplying emergency needs, the self-starting device should enable the two units to serve as backup for each other. That is, after the mains power failure and power outage are delayed and confirmed, a self-starting command will be issued. If the first unit self-starts three times in a row, If starting fails, an alarm signal should be sent and the second diesel generator should be started automatically.

(3) Selection of emergency diesel generator

The emergency unit should choose a diesel generator set with high speed, supercharging, low fuel consumption and the same capacity. The high-speed supercharged diesel engine has a large single unit capacity and occupies a small space; the diesel engine should be equipped with an electronic or hydraulic speed regulating device, which has better speed regulating performance; the generator should be a synchronous motor equipped with a brushless excitation or phase compound excitation device, which is more reliable and prevents faults. Low efficiency, low maintenance and repair Convenient; when the capacity of a single air conditioner or the capacity of the motor in the primary load is large, a generator set with third harmonic excitation should be selected; the unit is assembled on a common chassis with a shock absorber; a muffler should be installed at the outlet of the exhaust pipe , to reduce the impact of noise on the surrounding environment.

Selection of commonly used diesel generator sets

Some diesel generator sets need to be operated continuously for a certain period of time or often for a long time to serve as a common power supply for electrical loads. This type of generator set is called a common generator set. The common generator set can be used as a common generator set and a backup generator set. In towns, islands, forest farms, mines, oil fields and other areas or industrial and mining enterprises that are far away from large power grids, in order to supply local residents with power for production and daily life, diesel generators need to be installed. Such generators should be installed uninterrupted.

Important facilities such as national defense projects, communication hubs, radio stations, and microwave relay stations should be equipped with backup diesel generator sets. When such facilities use electricity, they can be supplied by the mains power grid. However, after the municipal power grid is damaged and causes a power outage due to earthquakes, typhoons, wars and other natural disasters or man-made factors, the backup units that have been set up should be started quickly and continue to operate uninterrupted for a long time to ensure the power consumption of these important projects. Continuous power supply to the load, this kind of standby generator set is also a common type of generator set. Commonly used generator sets have long working hours and large load curve changes. The selection of unit capacity, number, type and unit control method are different from emergency units.

1. Determination of the capacity of commonly used diesel generator sets

According to the long-term continuous operation of the unit, the output power can meet the calculated load selection of the entire project, and the backup unit capacity of the generating unit should be determined according to the importance of the load. The continuous output power of the diesel engine is generally 0.9 times the calibrated power.

2. Determination of the number of commonly used diesel generator sets

The number of commonly used diesel generator sets is usually more than 2 to ensure the continuity of power supply and adapt to changes in the power load curve. Only with a large number of units can the number of generator units invested can be determined according to changes in electrical load, so that the diesel engine can often run under economic load to reduce fuel consumption and power generation costs. The economic operating state of the diesel engine is between 75% and 90% of the rated power. In order to ensure the continuity of power supply, the commonly used unit itself should consider setting up a backup unit. When the unit is faulty or shut down for inspection, the generator set can still supply power to important electrical loads without interruption.

3. Determination of the speed of commonly used diesel generator sets

In order to reduce wear and increase the service life of the unit, commonly used generator units should choose medium or low-speed units with a calibrated speed of no more than 1000r/min, and medium or high-speed units can be selected as backup units. Units in the same power station should use units of the same model and capacity so that they can use the same spare parts and facilitate maintenance and management. For projects with large load changes, units of the same series with different capacities can also be selected. The determination of the generator output calibration voltage is the same as that of the emergency generator set, which is generally 400V. High-voltage generator sets can be used for projects with large power consumption and long transmission distances.

As a professional dieselGenerator setThe manufacturer, Haixing Power, has a say in the purchase of diesel generator sets. There is a big difference in the purchase of emergency diesel generator sets and common generator sets. Let the staff explain in detail the basis for purchasing diesel generator sets.

Emergency diesel generator selection

Emergency diesel generators are mainly used in important places. In the event of an emergency or accidental power outage, the emergency generator set can quickly restore and extend the power supply for a period of time. This type of electrical load is called a primary load. Equipment, instruments and computer systems that have strict requirements on power outage time should be equipped with batteries or UPS in addition to generators.

The work of emergency diesel generators has two characteristics:

The first feature is that for emergency use, the continuous working time is not long and generally only requires continuous operation for a few hours (≤12H);

The second feature is that it is used as a backup. The emergency generator set is usually in a shutdown waiting state. Only when the main power supply is completely interrupted, the emergency diesel generator set will start running to supply the emergency power load. When the main power supply returns to normal, it will switch immediately. downtime.

(1) Determination of emergency diesel generator generator capacity

The calibrated capacity of the emergency diesel generator set is the 12-hour calibrated capacity corrected by the atmosphere. Its capacity should be able to meet the emergency total calculated load, and should be verified based on the generator capacity that can meet the requirements for starting a single capacity motor in the first-level load. Emergency generators generally use three-phase AC synchronous generators with a calibrated output voltage of 400V.

(2) Determination of the number of emergency diesel generator sets

When there are multiple generator sets on standby, generally only one emergency diesel generator set is installed. For reliability reasons, two units can also be connected in parallel for power supply. The number of generator sets for emergency use should generally not exceed 3. When multiple units are selected, the units should try to use complete sets of equipment with the same model, capacity, and similar pressure and speed regulation characteristics. The properties of the fuel used should be consistent to facilitate maintenance and sharing of spare parts. When there are two generator sets for emergency use, the self-starting device should enable the two units to serve as backup for each other. That is, after the mains power failure and power outage are confirmed, a self-start command will be issued. If the first unit fails to self-start three times in a row, , an alarm signal should be sent out and the second diesel generator should be started automatically.

(3) Selection of emergency diesel generator

The emergency unit should choose a diesel generator set with high speed, supercharging, low fuel consumption and the same capacity. The high-speed supercharged diesel engine has a larger single unit capacity and takes up less space; the diesel engine should be equipped with an electronic or hydraulic speed regulating device, which has better speed regulating performance; the generator should be a synchronous motor equipped with a brushless excitation or phase compound excitation device, which is more reliable and prevents faults. Low efficiency, low maintenance and repair Convenient; when the capacity of a single air conditioner or the capacity of the motor in the primary load is large, a generator set with third harmonic excitation should be selected; the unit is assembled on a common chassis with a shock absorber; a muffler should be installed at the outlet of the exhaust pipe , to reduce the impact of noise on the surrounding environment.

Selection of commonly used diesel generator sets

Some diesel generator sets need to be operated continuously for a certain period of time or often for a long time to serve as a common power supply for electrical loads. This type of generator set is called a common generator set. The common generator set can be used as a common generator set and a backup generator set. In order to supply local residents with electricity for production and daily life, diesel generators need to be installed in towns, islands, forest farms, mines, oil fields and other areas or industrial and mining enterprises that are far away from large power grids. Such generators should be operated uninterrupted at ordinary times.

Important facilities such as national defense projects, communication hubs, radio stations, and microwave relay stations should be equipped with backup diesel generator sets. When such facilities use electricity, they can be supplied by the mains power grid. However, after the municipal power grid is damaged and causes a power outage due to earthquakes, typhoons, wars and other natural disasters or man-made factors, the backup units that have been set up should be started quickly and continue to operate uninterrupted for a long time to ensure the power consumption of these important projects. Continuous power supply to the load, this kind of standby generator set is also a common type of generator set. Commonly used generator sets have long working hours and large load curve changes. The selection of unit capacity, number, type and unit control method are different from emergency units.

1. Determination of the capacity of commonly used diesel generator sets

According to the long-term continuous operation of the unit, the output power can meet the calculated load selection of the entire project, and the backup unit capacity of the generating unit should be determined according to the importance of the load. The continuous output power of a diesel engine is generally 0.9 times the calibrated power.

2. Determination of the number of commonly used diesel generator sets

The number of commonly used diesel generator sets is usually more than 2 to ensure the continuity of power supply and adapt to changes in the power load curve. Only with a large number of units can the number of generator units invested can be determined according to changes in electrical load, so that the diesel engine can often run under economic load to reduce fuel consumption and power generation costs. The economic operating state of the diesel engine is between 75% and 90% of the rated power. In order to ensure the continuity of power supply, the commonly used unit itself should consider setting up a backup unit. When the unit is faulty or shut down for inspection, the generator set can still supply power to important electrical loads without interruption.

3. Determination of the speed of commonly used diesel generator sets

In order to reduce wear and increase the service life of the unit, commonly used generator units should choose medium or low-speed units with a calibrated speed of no more than 1000r/min, and medium or high-speed units can be selected as backup units. Units in the same power station should use units of the same model and capacity so that they can use the same spare parts and facilitate maintenance and management. For projects with large load changes, units of the same series with different capacities can also be selected. The determination of the generator output calibration voltage is the same as that of the emergency generator set, which is generally 400V. High-voltage generator sets can be used for projects with large power consumption and long transmission distances.