常用柴油发电机组的选择 常用发电机组持续工作时间长，负荷曲线变化较大，

Selection of <br><br>commonly used diesel generator sets The commonly used generator sets have a long working time and have a large load curve change. The capacity, number, and type of the set and the control method of the set are different from that of the emergency set. (1) Determination of capacity: According to the long-term continuous operation of the unit, the output power can meet the maximum calculation load selection of the whole project, and the reserve unit capacity of the generator 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 units: The general setting is usually more than 2 units to ensure the continuity of power supply and adapt to changes in the power load curve. Only when the number of units is large can the number of units to be put into the generator set be determined according to the changes in the electrical load, so that the diesel engine is often operated under economic load to reduce the fuel consumption rate and reduce the cost of power generation. The best economical operating state of the diesel engine is between 75%-90% of the rated power. In order to ensure the continuity of power supply, the common units themselves should consider setting up standby units. (3) Rotational speed determination: Generally, high-speed units with a rotation speed of 1000 to 1500 rpm should be selected for civil use, and low-speed units with a rotation speed of 300-350 rpm are suitable for marine main engines. (4) Determination of voltage: The determination of generator output voltage is the same as that of emergency generator sets, generally 400V, individual power consumption is large, and high-voltage generator sets can be used for projects with long power transmission distances. <br>When the <br><br>sum of the selected load capacity of the standby diesel generator set , multiplied by the required coefficient, the calculated load is less than the capacity of the emergency diesel generator set, the standby coefficient is considered according to 1.2, that is, the 1.2 times the calculated capacity is less than the capacity of the emergency diesel generator set. After a power failure, the emergency generator set supplies power to the load. When the sum of load capacity, multiplied by the required coefficient, the calculated load is greater than the capacity of a single emergency diesel generator set, two automatic generator sets with the same model, capacity, voltage regulation and speed regulation characteristics can be selected. After the mains power outage, one or two of the units will supply power for domestic and commercial use; when the mains power outage and a fire breaks out, two units will supply power to the fire-fighting load to facilitate firefighting. <br>Selection of emergency diesel generator<br><br>Emergency diesel generators should generally be high-speed, pressurized, low fuel consumption, and the same capacity diesel generator sets. High-speed supercharged diesel engines have a large single engine capacity and occupy a small space; diesel engines are equipped with electronic or hydraulic speed control devices, which have better speed control performance; generators should use synchronous motors with brushless excitation or phase compound excitation devices for more reliable performance and failure Low rate and convenient maintenance and repair; when the capacity of a single air conditioner or motor in the primary load is large, the generator set with third harmonic excitation should be selected; the machine is assembled on a common chassis with shock absorbers; smoke exhaust A muffler should be installed at the pipe outlet to reduce the impact of noise on the surrounding environment. (1) Determination of capacity: The emergency diesel generator set is used for emergency, and is often in standby emergency starting state. The continuous operation time is not long, generally no more than 8h, so the capacity can be determined according to the "standby power". Based on the sum of the capacity of the primary load (excluding the reserve capacity), the revised unit capacity is considered, and can meet the starting requirements of the largest motor in the primary load, and the capacity of the emergency diesel generator set is determined accordingly. Emergency generators generally use three-phase AC synchronous generators with a calibrated output voltage of 400V. (2) Determination of the number of units: Generally, one automatic generator set with a rotation speed of 1000-1500 rpm, brushless excitation, 400/230V, three-phase four-wire with control panel, charging and discharging equipment and a shared chassis is selected. May require a common chassis with daily fuel tanks to reduce pipelines and occupied area. In addition, from the perspective of reliability, two units can also be used for power supply in parallel. Generally, the number of emergency generating sets should not exceed 3. When selecting multiple units, the unit should try to select complete sets of equipment with the same model and capacity, similar pressure and speed regulation characteristics, and the nature of the fuel used should be the same for maintenance and sharing of spare parts.

Selection of commonly used diesel generator sets<br><br>Commonly used generator sets have long working hours, load curve changes greatly, unit capacity, number of units, type selection and unit control mode is different from emergency units. (1) Capacity determination: according to the long-term continuous operation of the unit output power can meet the maximum computing load selection of the whole project, and should be based on the importance of the load to determine the capacity of the generator set backup unit. The continuous output power of diesel engines is generally 0.9 times the calibration power. (2) The determination of the number of units: the general setting is usually more than 2 units, to ensure the continuity of power supply and adapt to the change of the electricity load curve. The number of units is large, in order to determine the number of units put into the generator set according to the change of electricity load, so that diesel engines are often operated under economic load, in order to reduce fuel consumption rate, reduce the cost of power generation. The best economical operating condition for diesel engines is between 75% and 90% of the calibrated power. In order to ensure the continuity of power supply, the commonly used units themselves should consider setting up spare units. (3) The determination of the speed: the general civilian should choose the speed of 1000 to 1500 rpm of high-speed units, and the speed of 300 to 350 rpm of low-speed units suitable for marine host. (4) Voltage determination: generator output voltage determination and emergency generator set is the same, generally 400V, individual electricity consumption is large, transmission distance of the project optional high-voltage generator set.<br>Selection of backup diesel generator sets<br><br>When the sum of the load capacity is multiplied by the calculated load after the demand factor is less than the capacity of the emergency diesel generator set, the backup factor is considered according to 1.2, i.e. 1.2 times the calculated capacity is less than the capacity of the emergency diesel generator set, which is powered by the emergency generator set after the power failure. When the sum of the load capacity is multiplied by the calculated load after the need factor is greater than the capacity of a single emergency diesel generator set, 2 automatic generator sets with the same capacity, pressure adjustment and speed control characteristics can be selected. After the power failure, one or two of the units to the life and commercial electricity supply, when the municipal power failure, and fire, by 2 units to the fire load power supply, in order to facilitate fire protection.<br>Selection of emergency diesel generators<br><br>Emergency diesel generators are generally suitable for the selection of high-speed, supercharged, low fuel consumption, the same capacity of diesel generator sets. High-speed supercharged diesel engine single-engine capacity is larger, occupy small space, diesel engine with electronic or hydraulic speed control device, speed control performance is better, generators should choose with brushless excitation or phase re-excitation device synchronous motor, more reliable, low failure rate, maintenance and maintenance is more convenient; When the capacity of a single air conditioner or motor is large in the first load, it is advisable to select a generator set with three harmonic excitations, the machine is assembled on a common chassis with shock absorbers, and the exhaust pipe outlet should be equipped with a muffler to reduce the impact of noise on the surrounding environment. (1) Capacity determination: emergency diesel generator set for emergency use, often in standby emergency start-up state, continuous operation time is not long, generally not more than 8h, so you can press the "spare power" to determine the capacity. According to the sum of the capacity of the primary load (excluding spare capacity), the modified unit capacity is considered and the starting requirements of the largest motor in the first load can be met, the capacity of the emergency diesel generator set is determined. Emergency generators generally use a three-phase ALTER generator with a calibration output voltage of 400V. (2) The determination of the number of units: generally choose 1 automation, speed 1000 to 1500 rpm, brushless excitation, 400/230V, three-phase four-wire with control screen, charge and discharge equipment and common chassis generator set. Shared chassis with daily fuel tanks can be required to reduce lines and footprint. In addition, from the reliability considerations can also choose 2 units in parallel power supply. The number of generator sets for emergency use should not generally exceed 3. When elected to use multiple units, the unit should try to choose the same model, the same capacity, pressure control, speed control characteristics of similar complete sets of equipment, the use of fuel properties should be consistent, in order to carry out maintenance and common spare parts.

Selection of common diesel generator set<br>The common generating units have a long working time, the load curve changes greatly, and the selection of unit capacity, number, type and control mode are different from emergency generating units. (1) Determination of capacity: according to the output power of long-term continuous operation of the unit can meet the maximum calculation load selection of the whole project, and the standby unit capacity of the generator unit should be determined according to the importance of the load. The continuous output power of diesel engine is generally 0.9 times of the rated power. (2) Determination of the number of units: generally more than 2 units are set to ensure the continuity of power supply and adapt to the change of power load curve. Only when the number of generating units is large, can the number of generating units be determined according to the change of power load, so that the diesel engine often runs under economic load, so as to reduce the fuel consumption rate and reduce the power generation cost. The best economic operation state of diesel engine is 75% - 90% of rated power. In order to ensure the continuity of power supply, the standby unit should be considered for the common unit itself. (3) Determination of rotation speed: Generally speaking, the high-speed unit with rotation speed of 1000-1500 rpm is suitable for civil use, while the low-speed unit with rotation speed of 300-350 rpm is suitable for marine main engine. (4) Determination of voltage: the determination of output voltage of generator is the same as that of emergency generator set, generally 400V. High voltage generator set can be selected for some projects with large power consumption and long transmission distance.<br>Selection of standby diesel generator set<br>When the sum of the load capacity multiplied by the demand factor is less than the capacity of the emergency diesel generator set, the reserve factor is considered as 1.2, that is, 1.2 times of the calculated capacity is less than the capacity of the emergency diesel generator set, and the emergency generator set supplies power to the load after the power failure. When the sum of the load capacity multiplied by the demand factor is greater than the capacity of a single emergency diesel generator set, two automatic generator sets with the same model, same capacity and similar characteristics of voltage regulation and speed regulation can be selected. In case of power failure, one or two units will supply power to domestic and commercial power; in case of power failure and fire, two units will supply power to fire fighting load to facilitate fire fighting.<br>Selection of emergency diesel generator<br>Generally, the diesel generator set with high speed, supercharging, low fuel consumption and the same capacity should be selected for emergency diesel generator. High speed supercharged diesel engine has large capacity and occupies small space; diesel engine is equipped with electronic or hydraulic speed regulating device, which has good speed regulating performance; generator should be equipped with synchronous motor with brushless excitation or phase compound excitation device, which is reliable, low failure rate and convenient for maintenance and repair; when the capacity of single air conditioner or motor is large in class I load, third harmonic excitation should be selected The exhaust pipe outlet should be equipped with muffler to reduce the impact of noise on the surrounding environment. (1) Determination of capacity: the emergency diesel generator set is used for emergency, often in standby emergency starting state, and the continuous operation time is not long, generally not more than 8h, so the capacity can be determined according to the "standby power". According to the sum of the capacity of the first level load (excluding the reserve capacity), considering the revised unit capacity, and meeting the starting requirements of the largest motor in the first level load, the capacity of the emergency diesel generator unit is determined. The emergency generator generally adopts three-phase AC synchronous generator, and its rated output voltage is 400V. (2) Determination of the number of units: generally, a generator set with automation, 1000-1500 rpm, brushless excitation, 400 / 230V, three-phase four wire control panel, charging and discharging equipment and common chassis is selected. The common chassis with daily oil tank can be required to reduce the pipeline and occupied area. In addition, considering the reliability, two units in parallel can be selected for power supply. Generally, the number of emergency generating units should not exceed 3. When multiple units are selected, complete sets of equipment with the same model and capacity and similar characteristics of pressure regulation and speed regulation shall be selected as far as possible, and the properties of fuel used shall be consistent, so as to facilitate maintenance and share spare parts.<br>