What Is Standby Generator Set - Emergency Diesel Generator

Standby diesel generator set: In the normal case, the power required by the user is supplied by the mains, and when the mains is cut off or the power is interrupted for other reasons, the generator set is set up to ensure the basic production and life of the user. Such generator sets are mainly located in telecommunications departments, hospitals, industrial and mining enterprises with tight supply of electricity, airports and TV stations. This kind of unit maintains the standby state at any time, can provide the continuous power supply to the non-constant load.

 

These standby generator sets only start power generation when the power system fails and both power supplies are powered off at the same time.

 

Setting principle

(1) When the civil building needs to be powered by the primary load requirement, if the urban power grid can provide two independent power sources (one for use and one for standby or mutual standby), the diesel generator set may not be provided. But when there is a particularly important load in the primary load, a diesel generator set should generally be provided as an emergency power power.

 

(2) When the power grid can only provide one power supply, in order to meet the power supply requirements for the first and second stage loads, a diesel generator set should be generally set up. At this time, the genset will be used as a backup power source and an emergency power source.

 

(3) In large and medium-sized commercial buildings, diesel generator sets should be installed to ensure that there is no major economic loss when the mains supply is interrupted. Because the urban power grid cannot be completely independent, sometimes another power supply may fail at the same time when one power supply fails or is overhauled. Therefore, even if there are two or more power supply, in order to ensure reliable power supply for fire protection and other important equipment (such as intelligent equipment, communication equipment, etc.) in civil buildings, diesel generator sets are generally installed.

 

Generator set selection

(1) The choice of the number of units. When the capacity of the generator set is selected by the motor starting capacity, the number of generators cannot be many, because the number of units increases, and the capacity of the single unit is small, which may fail to meet the starting requirements of the motor. Generally, when the capacity does not exceed 800 kW, it is better to use a single machine. When the capacity is above 800 kW, 2 units should be selected, and the physical parameters of the two units should be the same, which is convenient for the unit to run in parallel.

 

(2) The choice of other features. The civil construction standby emergency generator set should use high-speed diesel generator set and brushless automatic excitation device. The selected unit should be equipped with fast automatic starting and automatic power switching device, and should have the function of self-starting for 3 consecutive times. It is not suitable to start with compressed air. Generally, 24V battery pack is used as the starting power source.

 

Generator room setting

 

1. Plane layout of the machine room

 

When selecting the plane position of the machine room, it should be adjacent to the power distribution room as much as possible, because it is convenient for wiring, reducing the loss of materials and electric energy, and also convenient for management. If conditions permit, the machine room should be located on the first floor, which is convenient for ventilation, heat dissipation and smoke exhaustion. However, in high-rise buildings and large and medium-sized commercial buildings, the first floor is usually used as a commercial room, and the owners generally do not agree with this plan, so the machine room is often located in the basement. At this time, the following points should be noted in selecting the location of the equipment room:

 

(1) The machine room should have one side against the outer wall, so that the equipment ventilation, smoke exhaust is easier to deal with;

 

(2) It should be noted that the lifting, handling and maintenance of the unit is convenient. Generally, the parking garage access channel is used as the handling channel. However, if the passage is too small, the position of the lifting hole should be considered;

 

(3) Should avoid the damp place, do not set it under the regular water supply place such as the toilet, bathroom, pool, etc. or next door, to avoid toilet maintenance or floor seepage affecting the operation of the unit.

 

2. Ventilation and heat dissipation of the unit

 

Diesel engine, generator and exhaust pipe dissipate heat during operation, which increases the temperature of the machine room. If the temperature rises to a certain extent, it will affect the output of the generator. Therefore, measures must be taken to ensure the cooling of the unit. In the case of sufficient air intake and exhaust ventilation, the closed-type water circulation and air-cooled integral unit is generally used. Otherwise, the exhaust fan and the heat-dissipating pipe can be separated from the unit, and placed outdoor, and the outdoor heat dissipation pipe is connected with the diesel engine by a water pipe.

 

3. Smoke exhaust

 

When designing the smoke exhaust pipe system, the following points should be noted:

 

(1) The smoke exhaust system can reduce the back pressure as much as possible, because the increase of exhaust gas resistance will lead to the decrease of diesel engine output and the increase of temperature rise. Therefore, the shorter and straighter the exhaust pipe, the better.

 

(2) The exhaust pipe should be insulated to reduce scald and reduce thermal radiation to raise the temperature of the machine room.

 

(3) A muffler should be provided to reduce noise.

 

4. Noise processing

 

The selected units in general civil buildings are high-speed units. The noise is relatively large. In order to meet the requirements of environmental protection, the damping material should be set in the equipment room and the noise reduction measures should be taken. Since the actual situation of each project is very different, when selecting an emergency diesel generator set, in addition to meeting the standard requirement, it should be set according to the actual situation to achieve satisfactory results.

Source is from https://www.dieselgeneratortech.com/generator-sets/what-is-standby-generator-set.html