Due to theThe brand of diesel generator type, model, power is too much, such as the user the choose and buy diesel generators, don't know from He Xuan choice, also don't know what kind of generator is suitable for own use, need a what kind of standard, such as emergency and the common generator and what need to be considered, the dongguan team automation equipment co., LTD from diesel generating sets for you choose and buy, diesel generating sets based on the standard of choose and buy, emergency and selection method of commonly used diesel generator and other detailed introduces for everybody.Hope to help everyone generator when the choose and buy.

One, the basis of a diesel generator unit of choose and buy

1, the selected the performance of the diesel generator set, and the quality must conform to the requirements of the relevant standards

Diesel generator is widely used in telecommunications, financial department, hospital, school, business and other departments, industrial and mining enterprises and residential emergency standby power, military and fieldwork, vehicle and ship special purposes such as independent power supply.

As communication diesel generating sets, must achieve GB2820 G4-1997 grade G3 or the requirements of the class, and at the same time, the communication network access of diesel generating sets of quality certification testing out detailed rules for the implementation of "regulations of 24 performance requirements, at the same time, through to our country industry established by the competent department of communication power supply equipment quality supervision and inspection center strict inspection.

As a military communication diesel generating sets, must meet the related standard GB2820-1997, GJB and forces of the relevant departments of communication power supply equipment quality inspection standards, and to pass strict inspection on the quality of organization department of equipment.

2、The choice of diesel generator set should consider the main factors

Unit selection should consider the factors mainly include mechanical and electrical properties, the purpose of the unit, load capacity and range, automation, etc.
(1) the purpose of the unit.Due to the diesel generator set can be used on three kinds of commonly used, standby and emergency situations.Therefore different USES is different to the requirement of diesel generator set.
(2) the load capacity.Should choose according to different purposes of load capacity and load range, determine the diesel generating set of machine capacity and set aside Diesel generator set capacity.
(3) the unit use environmental conditions (mainly refers to the altitude and climate conditions)
(4) the choice of diesel generators
(5) generator and excitation mode choice
(6) diesel generator automation function

Second, the standard of diesel generating sets of choose and buy

　 Communication network access of diesel generating sets of quality certification testing rules > > 24 items prescribed by the performance index requirements:

　 1、Cosmetic requirements
(1) the boundaries of diesel generating set size, the size of the installation and connection size are conform to the prescribed procedures approved by the product design
(2) sets of welding should be solid, weld should be uniform, no welding wear, bite edge, slag inclusion and porosity, slag flux should be cleared;Coating should be uniform, without obvious crack and fall off;Coating shall be smooth, no plating leakage spots, such as corrosion phenomenon;Fasteners should be no loose unit.
(3) diesel generator electrical installation shall comply with the circuit diagram, the each wire connection of the unit should have a clear sign of not easy to fall off.
(4) diesel generator should be good grounding terminals.
(5) diesel generator panels complete content

2, insulation resistance and dielectric strength
(1) insulation resistance: the electric circuits of the independent of and the insulation resistance between circuit should be greater than 2 m
(2) insulation intensity: the unit for each independent electric loop and loop should be able to withstand the test voltage for 1 min, communication between should be no breakdown or flashing phenomenon.

Circuit voltage test voltage
<100V 750V 
≥100V 1440V

3、Phase sequence.Diesel generator set control panel terminal phase sequence of the look from the front control panel should be sorted from left to right or from top to bottom.

4、Diesel generators to maintain for running state requirements.Unit should have heating device, ensure the emergency start and rapid loading when the oil temperature, cooling medium temperature is not lower than 15 ℃

5, automatic start power supply, and the reliability of the automatic stop check
(1) joint control or remote control of the startup command, the diesel generator should be able to start automatically.
(2) the unit automatically start after 3 times failure, should signal launch failure;Has a spare unit, program should be able to start the system will automatically start instructions transmitted to another spare units.
(3) from the automatic startup instruction to supply power to the load time should not more than 3 min
(4) after the success of the diesel generator automatically start, loading calibration load should be not less than 50% for the first time.
(5) automatic control or remote control after the stop order, the unit should be able to automatically stop;With the utility grid and spare units, after the system recovery is often, diesel generator should be able to automatically switch or automatic stop, its means of downtime outage delay time should comply with the regulations of product technical conditions.

　 6, automatic startup success rate.Automatic startup success rate is not less than 99%.

　 7, no-load voltage setting range requirements.No-load voltage setting range of the unit is not less than 95% 105% calibration voltage.

　 8, automatic recharge function requirements.The unit should be able to automatically to launch the battery.

　 9, automatic protection function.Units should be lack of phase, short circuit (not more than 250 kw), over-current (not more than 250 kw), tachycardia, high water temperature cylinder temperature, low oil pressure protection.

　 10, line voltage waveform sine distortion rate.In the no-load voltage calibration, calibration frequency, line voltage waveform sine distortion rate < 5%.

11, the steady-state voltage regulation
≤250KW >250KW 
3% 2%

12, transient voltage regulation rate
≤250KW >250KW 
20% 15%

13, voltage stability time
≤250KW >250KW 
≤2s ≤1.5s

14, the voltage fluctuation rate
≤250kw >250kw 
0.8% 0.5%

15, frequency, steady state regulation
≤250kw >250kw 
3% 3%

16, frequency, transient regulation
≤250kw >250kw 
9% 9%

17, frequency stability time
≤250kw >250kw 
5s ≤5s

　18, frequency volatility
≤250kw >250kw 
0 or less.8% 0 or less.5%

19, under the asymmetric three-phase load voltage deviation
Diesel generating sets under the three-phase symmetrical load of 25%, plus 25% at any phase calibration phase power of resistive load, the unit should be able to work properly, line voltage of the maximum or minimum value with the three line voltage average value of 5%.

　20 and noise
From the noise of the diesel engine and generator unit 1 m in average sound pressure:
≤250KW >250KW 
≤102db(A) ≤108db(A) 
Noise standards:
Sleep < 45 db residential area of the ambient noise, should not exceed 50 decibels during the day, night should be below 45 decibels (40)
Work < 65 db under general people at around 40 decibels voice can maintain normal reaction and attention, but in more than 50 db environment work, after a long time can appear hearing loss, mood be agitated, can appear even the phenomenon such as neurasthenia.
Listen to the music 80 db children 80 decibels of noise environment life, cause the deaf-mute can reach 50%, only below 80 db noise level, to maintain work 40 years long not deaf;At 100 decibels, only 60% of the one who is, won't deafness.If people live for a long time in the 80 decibels of the environment, can lead to mood be agitated, hearing loss.Noise to the person's central nervous have damage effect, and can induce cardiovascular system diseases, eating in the strong noise environment, gastrointestinal blood capillary contraction happens, the secretion of digestive fluid and gastric bowel peristalsis weaken, the normal blood supply is damaged.Strong noise will cause abnormal pregnancy, developmental disorders in children.In daily life, therefore, try to minimize the noise source and transmission.
Below 85 decibels can cause mild hearing loss;
85 db - 90 db noise can cause a few deaf;
90-100 decibels can cause a certain amount of noise deafness;
100 decibels, can cause a considerable amount of noise deafness, these belong to chronic noise deafness.
105 decibels - 5 minutes of schizophrenia

21, specific fuel consumption.Nominal power unit in 120 < < can be within the scope of 600 KW, 260 g/KW or less fuel consumption.
22, diesel generator consumption rate.Power unit calibration > 40 kw, the unit consumption of 3 or less.0G/KW.H

23, run the test at the calibration condition 
In the units specified working conditions (GB2820 4.Calibration condition of normal section 2), the unit to run continuously for 12 h (including the 1 h overload 10%), and diesel generator set should be no water and air.

24, remote control, remote and remote sensing performance
(1) intelligent unit
More than 200 kw unit should be intelligent, its monitoring content and interface requirements are as follows:
(1) remote control: turn on/off switch, emergency stop, the main spare units.
(2) remote communication: working condition (run/stop), work (to be automatic/manual), mainly use unit, overvoltage, undervoltage, over current, frequency
(3) remote sensing: three-phase output voltage, three-phase output dynamic battery voltage, the output power.
(4) interface: should have communication interface (RS - 232 and RS - 485/422) and can provide complete communication protocol.

(2) the intelligent unit
Below 200 kw and the non intelligent unit without the remote control, remote and remote sensing requirements.

Third, the choice of emergency diesel generator

　 Emergency diesel generator is mainly used in important place, in an emergency or accident blackout moments after a power outage, through the emergency generator back quickly And to extend the time of a power supply.This kind of electricity load is called the primary load.Have strict request for electricity equipment, instrument and computer system, in addition to set should also be equipped with the generators or UPS battery power supply.

The emergency diesel generator work has two features:
The first characteristic is for emergency use, continuous working time is not long, generally only needs to continue to run a few hours (12 h) or less;
The second characteristic is as a standby, stop waiting for emergency generator at ordinary times, only when the main drum with power supply all disabled after power, emergency diesel generator set to begin running supply emergency power load, when the main power supply back to normal after the switch immediately stop.

(1) emergency diesel generator generator capacity determination

　 Calibration of emergency diesel generator set capacity of the 12 h after atmospheric correction calibration capacity, the capacity should be able to meet the emergency electric total computational load, and according to the generator capacity can satisfy the level load in the single largest capacity check the requirement of the motor starting.Three-phase ac is generally selected emergency generator The synchronous generator, the output voltage of 400 v

(2) determination of emergency diesel generator sets

　 When we have many sets of genset spare only commonly set 1 emergency diesel generator set, from a reliability considering also can choose 2 units in parallel to the power supply.Supply the urgent need of the generator sets should not be commonly more than 3 units.Elected by more than one unit, the unit shall be the same as far as possible choose model, capacity, voltage regulator, speed characteristics, complete sets of equipment of similar nature of the fuel used should be consistent, for maintenance and sharing of spare parts.When supply the urgent need of the generating sets have two (2), since the starting device should make 2 units can be as spare, namely the mains power failure without power after delay confirmation, since the starting order, if 1 units for three times since the start failure, should send out alarm signals and automatic starting 2 sets of diesel generator.

(3) the choice of emergency diesel generator

　 Emergency units appropriate chooses high speed, pressure, low fuel consumption, with the capacity of the diesel generator set.High speed turbocharged diesel engine capacity of large, empty small;Choose with electronic or hydraulic speed regulating device of diesel engine, speed control performance is better;Generator made selection with brushless excitation or phase compound excitation device of synchronous motor with, more reliable, low failure rate, maintenance is convenient;When the level of load capacity or single air conditioner in the motor capacity is larger, appropriate chooses three harmonic excitation generator set;The unit is installed on a common chassis; the shock exhaust pipe export should be installed muffler to reduce the influence of noise on the surrounding environment.

(4) emergency diesel generator set control

　 The control of the emergency generator should have fast self-starting and automatic input device.When the main power with power failure, emergency unit should be able to fast self-starting and restore power supply, power level 1 load to allow time from 10 seconds to a few seconds, shall be determined according to the specific situation.When using the power of important engineering after power, should first to the determination of 3-5 s time, in order to avoid instantaneous voltage to reduce switching and the city power grid investment of time or standby power supply automatically, and then starting emergency generator's instruction.From the instruction, the unit starting, acc to take full load over a period of time.Generally large and medium-sized diesel engine need prelubricated and the warming-up process, make emergency loads of engine oil pressure, oil temperature, cooling water temperature comply with the provisions of the factory product technical conditions;Prelubricated and warm-up process in advance according to different situations.Such as military communication, large important foreign affairs activities of the hotel, public building at night with a large mass activity, a hospital for surgery and other important emergency units at ordinary times should be in prelubricated and warm-up state, so that rapid start at any time, as far as possible to shorten the power failure time.

　 After the emergency units invested in, in order to reduce sudden load-up machinery and electric shock, under the condition of meeting the power supply requirement, the emergency load well according to the time interval grade increase.According to the national standard and national military standard, automated unit since starting for the first time after a successful allows loading quantity is as follows: for the nominal power is not more than 250 kw, for the first time allowed to load is less than 50% calibration load;For the nominal power is greater than 250 kw, according to the factory product technical conditions specified.If not strict instantaneous voltage drop and the transition process, the general unit by plus or dump load should not exceed 70% of the capacity of the unit calibration.

Fourth, the choice of commonly used diesel generator set

　Some diesel generator set in a certain period of time or continuously for a long time are often required, as a common power supply of power load, this kind of hair electricity called common generator unit.Commonly used generator can be used as common units and spare units.Away from the power grid of villages and towns, island, farm, mine, oilfield, such as region or industrial and mining enterprises, in order to supply the local residents living plants and living power, need to install the diesel generators, this kind of generating set should be continuously at ordinary times.

National defense engineering, communication hub, radio stations, microwave relay station and other important facilities, should have a standby diesel generator set.Such facilities at the level may by mains mains supply.However, because of the earthquake, typhoon, war and other natural disasters or man-made factors, the damage to the municipal power grid And power outages, has set the standby unit should be starting soon, and insisted on long-term continuously, in order to make sure the important engineering negative electricity load continuous power supply, the standby generator also belong to common type generator set.Commonly used generator continues to work long hours, load curve change is bigger, the unit capacity, sets, type selection and unit control mode and emergency units are different.

1、The determination of commonly used diesel generator unit capacity

　 According to the unit operation output power for a long time can meet the engineering computation load biggest choice, and should be determined according to the importance of load generating set with unit capacity.Continuous output power of diesel engine, generally for the nominal power of 0.Nine times. 

2、The determination of commonly used diesel generator sets

　 Set in the commonly used diesel generator sets are usually more than two (2), to ensure the continuity of power supply and to adapt to the changes in electricity load curve.Unit number, can be determined according to the change of electricity load into generator set to the Numbers, make the diesel engine running are often under the economic load, in order to reduce fuel consumption rate, decrease the cost of power generation.Diesel engine is the best economic operation state of between 75% and 90% in nominal power.To guarantee for the continuity of electricity, the commonly used unit itself should consider setting up spare unit, when troubleshooting or stop check, make the generator will still be able to supply the important power for electricity load constantly.

3, the commonly used The control of the diesel generator set

　 Commonly used, consideration should be given to parallel units in order to simplify the distribution of main wiring, starting, stopping rotation operation of generating unit, passed and the car, turned the moving load, switch without interruption of power supply unit.The unit should be installed with the unit of measurement and control device, speed and excitation regulation device of the unit Requirement should apply to fish in parallel.Standby generators for important load power supply, appropriate chooses automatic diesel generating set when external power after power failure, can quickly automatic starting, restore power to important loads.Diesel engine runtime engine room noise is very big, easy to build automation unit as compartment, automatic monitoring of generator operation.When the generator set on the rails, operators do not have to enter the diesel engine, in the control room to monitor diesel generating set.

4、 Commonly used determine the rotational speed of diesel generator set

　 In order to reduce wear, increase the service life of the unit, generator set appropriate chooses commonly used in the calibration speed is not more than 1000 r/min, low-speed units, the standby unit, high speed unit can choose.Units of the same plant should choose the same model, with the capacity of units, in order to use the same spare parts, convenient maintenance and management.Engineering change of load is big, also can choose series with different capacity of the unit.Determine the generator output voltage calibration of the same as the emergency generator, generally is 400 v, individual power consumption big, optional transmission distance of the project With high-pressure generator set.

Five, the diesel generator set order

After make the choices, diesel generating sets order shall indicate the following content commonly:
(1) of the unit model, rated power, rated frequency, rated voltage, rated current, phase number, power factor and connection mode, etc.
(2) the unit automation functionality and performance requirements.
(3) for diesel engine,The generator and the control panel The structure, performance, installation size requirements.
(4) for the parallel operation of the unit requirements: to buy more units at the same time, whether for parallel, such as the need to be parallel, should also be put forward is no need to provide the necessary parallel measuring instruments and devices.
(5) accessory equipment requirements for the unit: many domestic manufacturers the water cooling tank (heat sink), fuel tank and exhaust muffler, battery, etc Among the accessory equipment, when placing order, allow to install some requirements are put forward.