As everyone knows, diesel generators bring us a lot of convenience in our daily life. In high-rise buildings, when power outage, diesel generator is more needed. If you plan to have a diesel generator for high-rise buildings, suggest you to read this article.
1.Setting principles of diesel generators
The design of power supply in high-rise buildings, firstly must ensure under what situations should install diesel generators. Let's start with the load of high-rise buildings and so on.
A.Fire pumps, smoke control and exhaust facilities, fire elevators, emergency light and other fire-fighting power supply in high-rise buildings, according to local regulations, the first class of high-rise buildings should be supplied power with according to the one load requirements, and the second class of high-rise buildings should be supplied with electricity according to the two load requirements.
B.According to regulations of "Code for Electrical Design of Civil Buildings", in high-rise buildings, many parts of the load is one load, such as elevator power of the banquet hall, entertainment hall, hotel rooms, kitchens and important office buildings, main office, conference room lighting, business hall lighting of large department stores. And some parts load is two load, such as escalators in department stores, elevator power, main office and conference room lighting in ministry and provincial office buildings, etc. The load also contains other important loads, such as important transportation hubs, communication hubs and public places where a large number of people are often used for important international activities.
2.The load should be shared by two power sources.
When there is a suitable choice, second load also is powered by two return circuits, especially for the second load of fire power supply, it should supply power according to the requirements of the two loops of the second load. It can be seen that high-rise buildings require high reliability of power supply, which requires two power supply. Therefore, the principles for considering installation of diesel generator set are as follows:
A.For high-rise buildings which can provide two independent power sources for power grid, the requirements of two loads have been met according to the specifications. In principle, do not nee to install diesel generator set. However, for particularly important high-rise buildings (such as super high-rise buildings), there are special important loads in the interior. When the power system is overhauled or malfunctioned, the serious situation of another power system malfunction should be taken into account. At this time, diesel generating sets should generally be set up as emergency power supply.
B.For high-rise buildings where the local power grid can only provide circuit power, or where it is difficult or unreasonable to obtain two power sources, diesel power generators should be set up to provide two power sources. At this time, diesel generator set is used as standby power supply, not only for emergency use.
C.It is worth mentioning that in some high-rise buildings, even if the power supply of the city network is quite reliable and can meet the requirements of the specifications, self-contained emergency generating sets also need to set up, so that when the power supply of the city network is interrupted, the need for fire fighting and power consumption during the power outage can be guaranteed, and the basic order of the building can be maintained.
3.Capacity selection of diesel generator sets
In generally choose 20kw to 2400kw. There are many brands: Cummins, Volvo, Perkins, Deutz, Doosan, Ricardo, Shangchai, Yuchai, Weichai etc. If you do not know to choose which brand, we can recommend one for you according to your requirements.
4.Selection of diesel generator set type
There are three starting modes for diesel engine:
A.Manual starting mode. It means that start up diesel genset by hand.
B.Electric starting mode. Using motor as power and driving crankshaft by transmission mechanism, the diesel genset can be started. The power used for electric starting is battery, and the voltage is generally 24V. This type is the most used.
C.Compressed air starting mode. The compressed air into the cylinder of the diesel engine, using its pressure to drive the piston, so that the crankshaft of the diesel engine rotates, when the fixed speed is reached, stop air, and inject fuel into the combustion chamber, the diesel engine can be started. When the automatic signal is used to control the starting motor or the compressed air valve, and measures are taken for the lubrication system and cooling system, the diesel generator can start itself.
Electric starting mode should be adopted in high-rise buildings, and compressed air starting mode should be avoided. Diesel generator set with self-starting device must be selected in high-rise buildings of Class I. When the power supply of city power network is interrupted, the power supply must be within 15 seconds (30 seconds required by high-level regulations). When conditions exist in the second-class high-rise buildings, self-starting diesel genset should also be used, and when difficulties arise, the manual starting device can also be used.
5.Diesel generators speed
Diesel generating sets are classified into three categories according to speed: high, medium and low. High-speed (> 1000 rpm); medium speed (> 300-1000 rpm); low speed (> 300 rpm). High-speed units with rotational speeds of 1000-1500 RPM should be selected in high-rise buildings, this kind of generator has the advantages of small size, light weight and reliable operation.
During diesel engine working, due to the combustion of diesel oil produces high temperature, in order to ensure that the heating parts and supercharger shell of diesel engine are not affected by high temperature, and to ensure the lubrication of each working face, it is necessary to cool the heating part.
There are two cooling modes of diesel engine: water cooling and air cooling. Water cooling means cooling cylinder with water and air cooling means cooling cylinder with air. Water-cooled generators are divided into closed self-circulating water cooling units and open circulating water cooling units. In high-rise buildings, the diesel generator set with closed water circulation cooling mode should be chosen in general, which occupies a small area and space.
Excitation system is the main component of generator. There are many kinds of excitation devices. Brushless automatic excitation devices are usually chosen in high-rise buildings. The advantage of this excitation method is that when used in conjunction with the automatic voltage regulator, the static voltage regulation rate can be guaranteed to be within +2.5%. This type of generator can adapt to various operation modes, and is easy to realize the automation of the unit or remote control of the generating set.
After you learn this article, i believe you have known to choose which type of diesel generator. If you still have confusion, you can contact us by firstname.lastname@example.org. We believe we can let you do not have any trouble during use diesel generator.