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Title: Diesel generator sets an optional basis
Time: 2013/7/11 11:20:37
A diesel generator sets an optional basis

1 The selected diesel generator performance and quality must meet the relevant standards

Diesel generators are widely used in telecommunications, finance departments, hospitals, schools, business and other departments, industrial and mining enterprises and residential emergency backup power, military and field operations, vehicles and vessels and other special purpose independent power.

Diesel generator sets as the communication must reach GB2820-1997 in G3, or G4 level requirements, and also to "Communication diesel generator set network quality certification testing implementation details" provided 24 performance requirements, while through our industry department established communication power equipment Quality Supervision and Inspection Center of rigorous testing.

As a military communications diesel generator sets, you must meet the relevant GB2820-1997, GJB relevant standards and force departments to develop a "communication power equipment, quality testing standards" requirement, and the organizations concerned departments through strict quality inspection equipment.

(2) the choice of diesel generator sets should be considered a major factor

Select the unit main factors that should be considered mechanical and electrical performance, the unit uses, load capacity and range of automation functions.
(A) the use of the unit. As diesel generator sets can be used in common, such as three kinds of backup and emergency situations. Therefore, different uses for diesel generator sets demanded differ.
(2) load capacity. Should be selected according to different uses load capacity and load range, determine the stand-alone diesel generator set machine capacity and standby diesel generator set capacity.
(3) the use of crew environmental conditions (mainly refers to the altitude and climatic conditions)
(4) the choice of diesel generators
(5) the choice of the generator and excitation mode
(6) diesel generators automation function selection

The diesel generator set optional criteria

Communication with the diesel generator set network quality certification testing implementation details >> prescribed 24 performance requirements:

1 appearance requirements
(1) diesel generator set boundaries size, installation dimensions and connection dimensions are in line with prescribed procedures approved factory goods pattern
(2) the unit shall be securely welded, weld should be uniform, no welding wear, undercut, slag and porosity and other defects, welding slag, welding flux should be cleaned; film should be uniform, no obvious cracks and fall off; coating should be smooth , seamless plated spots, rust and other phenomena; crew fasteners should not be loose.
(3) diesel generator electrical installation shall comply with schematics, wire connections for each unit should be easy to fall off the clearly marked.
(4) diesel generators should have a good grounding terminals.
(5) complete diesel generator signage content

2 insulation resistance and dielectric strength
(1) Insulation resistance: each independent electrical circuit between the ground and the circuit insulation resistance should be greater than 2M
(2) Dielectric strength: units each independent electrical circuit between the ground and the circuit should be able to withstand the AC test voltage 1min, there should be no breakdown or flicker.

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

3 phase sequence requirements. Diesel generator set control panel terminal phase sequence from the front control panel shall see from left to right or top to bottom order.

4 ready to run diesel generators to maintain the state requirements. Crew should have heating device to ensure its emergency start-up and fast loading of oil temperature, coolant temperature not lower than 15 ℃

5 automatic startup and automatic shutdown of power supply reliability checks
(A) access controlled or remote start command, the diesel power generation should be able to start automatically.
(2) the unit automatically starts after the 3rd failed, failed to start signal shall be given; has a standby unit, the program should be able to boot the system automatically starts the command is passed to another standby unit.
(3) from the automatic start instruction is issued to the supply to the load time should not exceed 3min
(4) After the success of diesel generators automatically started, first load volume should not be less than 50% of the calibration load.
(5) access controlled or remote shutdown command, the unit should be able to automatically shut down; For use with mains and standby units, when the grid is back to normal, diesel generators should be able to automatically switch or automatic shutdown, shutdown delay its shutdown mode Time should be consistent with product technical conditions require.

6, automatic startup success rate. Automatically starts the success rate is not less than 99%.

7, no-load voltage setting range requirements. Unit load voltage setting range is not less than 95% -105% Cal.

8, automatic replenishment functional requirements. Unit should be able to automatically start charging the battery.

9, automatic protection requirements. Unit should phase, short circuit (not more than 250KW), over current (less than 250KW), over-speed, high-temperature cylinder temperature, oil pressure protection.

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

11 Steady state voltage regulation rate
≤ 250KW> 250KW
3% 2%

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

13, the voltage stabilization time
≤ 250KW> 250KW
≤ 2s ≤ 1.5s

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

15 Steady state frequency regulation rate
≤ 250kw> 250kw
3% 3%

16 Transient state frequency regulation rate
≤ 250kw> 250kw
9% 9%

17, the frequency settling time
≤ 250kw> 250kw
5s ≤ 5s

18, the frequency fluctuation rate
≤ 250kw> 250kw
≤ 0.8% ≤ 0.5%

19, three-phase unbalanced load voltage deviation
Diesel generator set at 25% of the three-phase symmetric load, in any phase plus 25% of the calibration phase power resistive load, the unit should be able to work properly, the maximum or minimum line voltage line voltage with three average 5%.

20, the noise
Engine and generator unit at a distance of 1m at the noise pressure average:
≤ 250KW> 250KW
≤ 102db (A) ≤ 108db (A)
Noise standards:
Sleep <45db neighborhood ambient noise during the day should not exceed 50 decibels at night should be less than 45 (40) dB
Work <65 db 40 db average person around at the sound can be maintained normal reaction and attention, but at 50 decibels or more in the work environment, a long time will be hearing loss, emotional irritability, and even debilitating neurological and so on.
Music 80db noise above 80 decibels children live in an environment, resulting in up to 50% of the deaf-mute, noise level only 80 db or less, in order to maintain long-term work for 40 years without deafness; at 100 dB, only 60% of people do not would deafness. If you have long lived in an environment above 80 decibels can cause emotional irritability, hearing loss. Noise is harmful to the human central nervous system and can cause cardiovascular diseases, in strong noise environment, eating, gastrointestinal contractions occur capillaries, digestive juice secretion and gastrointestinal motility will be weakened, so that normal blood supply has been damaged. Intense noise can also cause abnormal pregnancy, children's mental retardation. Therefore, their daily lives to minimize noise sources and propagation.
85 db The following may cause a slight hearing loss;
-90 Db 85 db noise can cause deafness few people;
90-100 decibels can cause a certain amount of noise-induced hearing loss;
100 db or more, it will cause a considerable amount of noise-induced hearing loss, these are chronic noise-induced deafness.
105 db above --- 5 minutes schizophrenia

21, fuel consumption rates. Rated power unit at 120 <Ne <600kW range, fuel consumption rate ≤ 260G/KW.H

22, diesel generators consumption rates. Unit rated power> 40KW, the unit consumption rate ≤ 3.0G/KW.H

23, running test at standard conditions
Unit at the required operating conditions (GB2820 in 4.2), the unit can be calibrated condition normal continuous operation 12h (including 10% overload run 1h), and diesel generator sets should be no leakage and leakage phenomenon.

24, remote control, remote and telemetry performance
(1) intelligent unit
200KW or more units should be intelligent, its monitoring content and interface requirements are as follows:
① Remote control: on / off, emergency stop, switch the main and backup units.
② telesignalling: work status (up / down), work (automatic / manual), mainly used units, overvoltage, undervoltage, overcurrent, frequency
③ Telemetry: Three-phase output voltage, three-phase output dynamic battery voltage, output power.
④ Interface: should have a communication interface (RS-232 and RS-485/422) and can provide a complete communication protocol.

(2) non-intelligent unit
200KW and below the non-intelligent unit without remote control, and telemetry requirements.

Third, the choice of the emergency diesel generators

Emergency diesel generator is mainly used for important places, in case of emergency or power outage after a moment, quickly restored through emergency generators and power for an extended period time. Such electricity load called a load. There are strict requirements for power outages of equipment, instruments and computer systems, in addition equipped with generators should be located outside of the battery or UPS.

The work of the emergency diesel generators have two characteristics:
The first one is characterized for emergency use, continuous working time is not long, usually require only a few hours continuous operation (≤ 12H);
Section 2 is characterized as a backup, emergency generators usually is shutdown wait state only when the main power supply after power failure all the drums, before starting the emergency diesel generators supply emergency electricity load operation, when the main power is restored immediately after switching downtime.

(A) emergency diesel generator generating capacity to determine

Calibration of the emergency diesel generator set capacity after 12h after atmospheric correction calibration capacity, its capacity should be able to meet the emergency power total computational load and press the generating capacity to meet a maximum load capacity of a single motor starting requirements for verification . Emergency generator is generally used in the three-phase AC synchronous generator, its rated output voltage is 400V

(2) emergency diesel generators to determine the number of units

Have multiple backup generators, generally only set one emergency diesel generator sets, from reliability considerations can also use two units in parallel for power. Supply urgently generator set for generally not more than 3 units. Elected with multiple units, the unit should try to use models, the same capacity, voltage, speed characteristics similar equipment, the nature of fuel used should be consistent in order to carry out maintenance and sharing of spare parts. When the supply of urgently generators have two sets, the self-starting device should make the two units can spare each other, ie mains power failure outage after delay confirmation, issued since the start command, if the first one since 3 consecutive units Failure to start, should send alarm signals and automatically start the first two diesel generators.

(3) the choice of the emergency diesel generators

Emergency crew should use high-speed, turbocharged, low fuel consumption, with the capacity of diesel generator sets. High-speed turbocharged diesel engine unit capacity is large, small footprint; diesel use with electronic or hydraulic control devices, speed performance is better; generators should use with brushless excitation or phase compound excitation device synchronous motor, a more reliable, fault rate, more convenient maintenance and overhaul; when a load capacity of a single air conditioner or motor capacity is larger, should be selected harmonic excitation generator sets; machines assembled on a common chassis with shock absorbers; exhaust muffler outlet pipe should be installed to reduce the noise impact on the surrounding environment.

(4) emergency diesel generator set control

Emergency generator set control should have rapid self-starting and automatic feeding device. When the main power after a power failure, the emergency crew from the start and should be able to quickly restore power, an allowable load from ten seconds to tens of seconds off time should be determined according to specific circumstances. When important project's main source of power, the first shall be determined over 3-5S's time to avoid instantaneous voltage drop and the city grid or BZT closing time, and then start issuing instructions for emergency generating sets . From the command is issued, the crew began to start, acceleration to be able to take some time with a full load. Generally large and medium-sized diesel engines also need to pre-lubricated and warming process, so that emergency load oil oil pressure, oil temperature, coolant temperature meet technical conditions of factory goods; pre-lubricated and warming up process can be carried out in advance according to different situations. Such as military communications, large hotels important foreign affairs activities, large-scale public buildings at night mass activities, hospitals and other important surgical emergency unit should be in the usual pre-lubricated and warm state, in order to keep fast start, try to shorten the fault off time .

Input for emergency units, in order to reduce the mechanical load suddenly and current impact, to meet the power requirements of the case, the emergency load is preferably increased by Interval classification. According to national standards and national military standards, automation units for the first time after the success from the start to allow the loading capacity is as follows: For those who rated power less than 250KW, for the first time allows loading of not less than 50% of the calibration load; rated power than 250KW for those who, according to plant Commodities technical conditions require. If the instantaneous voltage drop and the transition process is not strictly required, the general unit of sudden load or unload units are rated at not more than 70% of capacity.

Fourth, the common choice of diesel generator sets

Some diesel generator set to a long period of time or frequently carried out continuously, as a common electrical load power supply, commonly known type of turbine generators. Used generator sets can be used as common unit and the standby unit. Away from large grid towns, islands, forestry, mining, oil and other regions or the mining industry, in order to supply local residents plant health and life electricity, you need to install diesel generators, such generators usually should be uninterrupted.

Defense engineering, communications hub, radio, microwave relay stations and other important facilities, shall be provided with standby diesel generator sets. Such facilities can usually mains electricity supply grid. However, due to earthquakes, typhoons, and other natural disasters, war or human factors, so that the destruction of the city grid power outage after the standby unit has been set should start quickly and stick long-term continuous manner, to ensure that these important projects for electricity continuous power supply to the load, this group also belong to the standby generators used generator type. Used generator sets continued to work long hours, the load curve larger unit capacity, number of units, type selection and control units and emergency units of different ways.

One commonly used to determine the capacity of diesel generator sets

Long-term continuous operation at the unit output power can meet all engineering computational load maximum choice and should be based on the importance of determining the load capacity of the generator set standby unit. Diesel ongoing output power, typically 0.9 times the rated power.

Two commonly used diesel generator to determine the number of units

Used diesel generator set number of units usually 2 units or more, in order to ensure continuity of supply and to adapt to changes in electricity load curve. Multi-unit Number of units before they can change depending on the electrical load to determine the conduct of investment in generating units Number of units, the engine is often running under load in the economy in order to reduce fuel consumption and reduce electricity costs. The best economic engine running at rated power between 75% -90%. In order to ensure continuity of supply, commonly used units themselves should consider setting the standby unit, when the unit failure or downtime maintenance inspection, the generator set is still important to be able to meet the continuous supply of uninterrupted electricity load.

3 commonly used to determine the speed diesel generator sets

In order to reduce wear and increase the life of the unit, commonly used generator sets should use no more than 1000r/min rated speed of the low-speed unit, its optional standby unit, a high-speed unit. Should use the same power plant units of the same model, with the capacity of the unit in order to use the same spare parts, easy maintenance and management. Load changes of project, or you can use the same series of different capacity of the unit. Calibration voltage generator output to determine the same and emergency generator sets, typically 400V, individual electricity capacity, transmission distance engineering can choose high pressure turbine.

4 used diesel generator set control

Common units should generally be considered to be in parallel to simplify distribution main wiring, and the unit start, stop rotation runs through and trucks, transfer load, switching power supply unit without interruption. Unit should be installed with the unit measuring and control devices, speed control and excitation control unit device should be parallel with the requirements applicable to the fish. Critical load power standby generator sets, automatic diesel generator set should be chosen when the external power after a power failure, can quickly start automatically restore power to critical loads. Runtime engine room noisy, automated transformation of crew compartments for easy operation, automatic monitoring of generator sets. When the generator normally, the operator does not have to enter the engine room, in the control room can be monitored for diesel generator sets.

Five, diesel generator set order request

After making the above selections, diesel generator set shall be marked with the following general order:
(1) unit model, rated power, rated frequency, rated voltage, rated current, phase, power factor and wiring methods.
(2) on the unit automated functional and performance requirements.
(3) for diesel engines, generators and control panel structure, performance, installation size requirements.
(4) requirements for units operating in parallel: To purchase multiple units, whether to require parallel conduct, such as the need to be connected in parallel, but also raised the need to provide the required parallel measuring instruments and devices.
(5) of the unit ancillary equipment requirements: many domestic manufacturers to cooling water tank (radiator), fuel tank, exhaust muffler, battery, also regarded as ancillary equipment, installed in order to allow some proposed requirements.
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