Diesel generator sets optional basis

1. The selected diesel generator group performance and quality must comply with the requirements of the relevant standards

The diesel generators are widely used in the department of telecommunications, finance departments, hospitals, schools, commercial, industrial and mining enterprises and residential emergency standby power, military and field operations, vehicles and ships, and other special-purpose independent power.

Diesel generator sets as the communication must reach the requirements specified in GB2820-1997, G3 or G4, and communication diesel generator sets into the network quality certification testing implementation details "under the 24 performance requirements, at the same time at the same time through strict inspection of our industry department in charge of the establishment of the communication power equipment Quality Supervision and Inspection Center.

Diesel generator sets as military communications, must meet the GB2820-1997 GJB standards and forces departments to develop "the communication power equipment quality testing standards, regulations, and through the organization department of the rigorous testing of the quality of the equipment.

Choice of diesel generator sets should be considered a major factor

The unit selection factors should be considered major mechanical and electrical properties, the use of the unit, load capacity and range, and automation capabilities.
(1) the use of the unit. The diesel generator sets can be used for three kinds of commonly used, standby and emergency situations. The requirements of the different uses of diesel generator sets differ.
(2) load capacity. Shall be selected according to the different uses of load capacity and load range, determine the capacity of of Diesel Genset machine unit capacity and standby diesel generator sets.
(3) the use of the unit environmental conditions (mainly refers to the altitude and climatic conditions)
(4) the choice of the diesel generator
(5) generator and excitation mode selection
(6) diesel generator automation function selection
Standard diesel generator sets to buy

Communication with the diesel generator sets into the network quality certification testing implementation details of 24 >> performance requirements:

1. Appearance requirements
(1) the boundaries of the diesel generator set size mounting dimensions and connection dimensions are in line with prescribed procedures approved factory goods pattern
(2) welding unit should be firm, should be uniform weld, solderless wear undercut folder slag and porosity and other defects, welding slag welding drugs should be clean; film should be uniform, no obvious crack and fall off; coating should be smooth seamless plated spots, rust and other phenomena; crew fasteners should not be loose.
(3) the electrical installation of diesel generators should comply with the circuit diagram, the unit wire connections should be easy to fall off the clear sign.
(4) diesel generators should have a good grounding terminal.
(5) complete the diesel generator signage content

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

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

3 phase sequence requirements. Phase sequence from the front of the control panel to see the diesel generator set control panel terminals should be sorted from left to right or from top to bottom.

4 diesel generators to maintain the ready to run state requirements. The unit should have a heating device, to ensure its emergency start and fast loading oil temperature, coolant temperature not less than 15 ° C

5 start automatically reliability check of the power supply and automatic shutdown
(1) then self-control or remote control start command after diesel power generation should be able to start automatically.
(2) The unit starts automatically after 3 failed, should issue failed to start signal; equipped with reserve units, the program starts, the system should be able to automatically start command passed to another standby unit.
(3) from the automatic start command issued to power the load time should be no more than 3min
(4) diesel generator starts automatically after the success of the first loading amount should not be less than 50% calibration load.
(5) then self-control or remote shutdown command, the unit should be able to automatically shut down; standby unit and with the electricity grid, when the grid back to normal after the diesel generator should be able to automatically switch or automatic shutdown shutdown shutdown delay Time should be consistent with the technical requirements of the product.

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

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

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

9, automatic protection function requirements. The unit should be lack of phase, short circuit (not more than 250KW), over current (not more than 250KW), over-speed, water temperature cylinder temperature high, low oil pressure protection.

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

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

12, the voltage transient adjustment rate
≤ 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, the frequency of the steady-state regulation
≤ 250kw> 250kw
3% 3%

16, the frequency of transient adjustment rate
≤ 250kw> 250kw
9% 9%

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

18, the frequency volatility
≤ 250kw> 250kw
≤ 0.8% ≤ 0.5%

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

20, the noise
The average noise sound pressure at 1m from the crew of the diesel engine and generator:
≤ 250KW> 250KW
≤ 102db (A) ≤ 108db (A)
Noise standards:
Sleep <45db neighborhood environmental noise during the day and not more than 50 db at night should be less than 45 (40) dB
Work <65 db average person around 40 db sound can maintain a normal reaction and attention, but the work environment of 50 dB or more, the time will be a long hearing loss, irritability, mood, even neurasthenia and so on.
Listen to music 80db children living in more than 80 db noise environment, resulting in up to 50% of the deaf-mute, noise level only 80 dB below, in order to maintain long-term work for 40 years and will not deafness; 100 db, only 60% of the people do not would deafness. If you have long lived in the environment above 80 decibels will cause emotional irritability, and hearing loss. Noise is harmful to the human central nervous and cardiovascular system diseases, eating in strong noise environment, gastrointestinal capillaries shrink, secretion of digestive juice and gastrointestinal motility will be weakened, so that normal blood supply is damaged. Strong noise can also cause abnormal pregnancy, children's mental retardation. Therefore, daily life, to try to reduce the noise sources and propagation.
85 dB can cause slight hearing loss;
85 db -90 dB noise-induced hearing loss can cause a small number of 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 is a chronic noise-induced hearing loss.
105 dB or more --- 5 minutes schizophrenic

21, the rate of fuel consumption. Rated power of the unit at 120
22, the consumption rate of diesel generators. Units are rated power> 40KW, unit consumption rate ≤ 3.0G/KW.H

23, running tests in the standard conditions
Unit work under the conditions specified in 4.2 (GB2820), the unit can properly calibrate mode continuous operation 12h (including 10% overload run 1h), and diesel generator sets should be no leaks and air leaks.

24, remote control, remote telemetry performance
(1) Unit intelligent
200KW or more units shall be intelligent, to monitor the content and interface requirements are as follows:
① remote control: on / off, emergency stop, switch the main and standby unit.
(2) telesignalling: work status (run / stop), work (automatic / manual), crew, overvoltage, undervoltage, overcurrent, frequency
The ③ Telemetry: three-phase output voltage, three-phase output dynamic battery voltage and output power.
The ④ interface: communication interface (RS-232 and RS-485/422) and can provide a complete set of communication protocols.

(2) non-intelligent unit
200KW and below the non-intelligent unit without remote control, remote telemetry requirements.
Third, the choice of the emergency diesel generator

Emergency diesel generators for an important place in an emergency or accident blackout after momentary power failure, emergency generator sets quickly restore and extend the period of supply time. Such electricity load called a load. Equipment, instruments and computer systems, there are strict requirements on power-off time, in addition to the set should also be equipped with generator powered battery or UPS.

The work of the emergency diesel generators have two characteristics:
A feature for emergency use, continuous working time is not long, generally only need to run continuously for several hours (≤ 12H);
2 is characterized as a backup, usually in downtime waiting for emergency generating sets, and only when the main source of all power drum impaired, the emergency diesel generators only start running to supply emergency electricity load, when the main power supply back to normal, then switch downtime.

(1) emergency diesel generator generator capacity determination

The nominal capacity of the emergency diesel generators 12h atmospheric correction calibration capacity, its capacity should be able to meet the emergency power computational load, press the generating capacity to meet the requirements of a load in a single maximum capacity motor starter check . The emergency generator is generally used in the three-phase AC synchronous generator, its nominal output voltage of 400V

(2) The emergency diesel generators sets to determine the number

Have more than one generator set spare, only to set up an emergency diesel generator sets, 2 units in parallel for power supply can also choose from a reliability considerations. The number of units of the generator sets supply emergencies generally not more than three units. Elected with more than one unit, the unit should try to use models, the same capacity, voltage, speed characteristics similar equipment used in the nature of the fuel should be the same, in order to carry out maintenance and sharing of spare parts. Self-starting device should supply emergency generator sets 2 sets of 2 units can standby for each other, that mains power failure outage after delay after confirmation, issued since the start command if the first unit for three consecutive times since Failure to start, should send an alarm signal and automatically starting the second diesel generator.

(3) selection of the emergency diesel generators

The emergency crew is better to use the high-speed, turbocharged, low fuel consumption, diesel generator set with capacity. High-speed turbocharged diesel engine unit capacity of the space occupied by small; diesel engine chosen with electronic or hydraulic speeder, better speed performance; generator should use with brushless excitation or phase compound excitation synchronous motor device, more reliable, fault low, more convenient maintenance and overhaul; When a load in a single air-conditioner capacity or motor capacity is large, should use the third harmonic excitation generator sets; machines assembled on a common chassis with shock absorbers; exhaust The tube outlet should be installed muffler to reduce the noise impact on the surrounding environment.

(4) emergency diesel generator control

Emergency generator control should be fast from the start and automatic switching devices. When the power failure of the main power supply failure, the emergency unit should be able to fast from the start and the restoration of electricity, a load to allow power-off time from ten seconds to tens of seconds, should be determined according to the specific situation. Important works of the Lord with power outages, should be based on the 3-5S to determine the time, in order to avoid the instantaneous voltage drop and the City the grid closing or standby power automatically invested time and then issued instructions to start emergency generator set . Issued from the command, the crew began to start or speed to be able to take some time with a full load. Generally large, medium-sized diesel engines also require pre-lubricated and warm-up process, so that the emergency oil loaded oil pressure, oil temperature, the temperature of the cooling water in line with the provisions of the technical conditions of factory goods; pre-lubricated and warm-up process can advance according to different situations. Important foreign affairs activities such as military communications, large hotels, public buildings at night to carry out large-scale mass activities, hospital for surgery emergency unit usually should be in the state of pre-lubricated and warm-up for fast start, shorten the fault power-off time .

After the emergency crew inputs is performed, in order to reduce the mechanical and current impact when the load suddenly, in the case of satisfying the power requirements, the emergency load is preferably at time intervals graded increased. According to national standards and national military standard provides automated crew from the start after the success of the rated power is greater than the first time allows the loading amount is as follows: the calibration power less than 250KW who load of not less than 50%, for the first time allows the calibration of the load; 250KW provisions, according to the technical conditions of factory goods. If the instantaneous voltage drop, and the transition process is not strict requirements, general units sudden load or unload suddenly should not exceed 70% of the units are rated capacity.

Common diesel generator sets

Some diesel generator sets in a certain period of time or often take a long time continuously as common electricity load power supply, this type of generator set is called a common generator sets. Commonly used generator set can be used as a common unit and the standby unit. Township, island, forest, mining, oil field and other areas away from the grid or industrial and mining enterprises, in order to supply the the local residents raw plant and electricity consumption, the need to install diesel generators, this type of generator sets usually be uninterrupted.

Defense engineering, communications hub, Radio, microwave relay stations and other important facilities shall be provided with standby diesel generator sets. Usually such facilities, electricity supply mains power grid. However, due to earthquakes, typhoons, wars and other natural disasters or man-made factors, the destruction of the city grid power outage, the standby unit should be set quickly start and adhere to long-term uninterrupted, to ensure that these important projects and power load continuous power supply, which also belongs to the commonly used type of generator sets for standby generator sets. Commonly used generator sets continued a long time, the load curve, the capacity of the units, number of units, type selection and control of the unit and Emergency unit.

1. commonly diesel generator set capacity to determine

The output power to meet the the press unit long-term continuous operation-wide maximum computational load selection should be determined based on the importance of load and generator sets spare capacity of the units. Diesel ongoing output power, generally of 0.9 times the rated power.

2. Station to determine the number of common diesel generator sets

Commonly diesel generator set number set is usually more than 2, in order to ensure continuity of supply and to adapt to changes in the electricity load curve. The crew station number, the identification of the number of units of the generator sets can only be based on changes in the electricity load, the engine often run economic load, in order to reduce fuel consumption rate, and reduce the cost of power generation. The best economic and operational status of the diesel engine is between 75% -90% of the power calibration. In order to ensure continuity of supply, commonly used unit should consider setting up a standby unit, when the unit troubleshooting or down to check for the sets will still be able to meet the continued uninterrupted supply of important electricity load.

Commonly used in diesel generator sets speed determination

In order to reduce wear and increase the life of the unit, commonly generator group advised to use the rated speed of not more than 1000r/min, low-speed unit, the standby unit selectable, high-speed units. The units of the same power plant should be used in the same model, with the capacity of the unit, in order to use the same spare parts, easy maintenance and management. Engineering of large load changes, and can also choose different capacity units in the same series. Determine calibration voltage generator output and emergency generator sets, generally is 400V, the individual consumes huge quantities transmission distance engineering choice of high-voltage generator sets.

4. common diesel generator sets control

Common unit generally should be considered capable of parallel conduct to simplify the main wiring for electricity, the unit start, stop rotation run, and the car, transfer load switching unit without interrupting power supply. Unit unit of measurement and control devices should be installed, the the unit governor and excitation regulator device shall apply the requirements of the fish parallel. Important load power standby generator sets, automatic diesel generator set should be chosen when the power of the external power failure can quickly start automatically, to restore the power supply to the critical load. Diesel engine running when the engine room noise, automation units to facilitate the transformation of the operating compartment, the automatic monitoring of the generator set. When the generator set is normally the operator does not have to enter the engine room, in the control room can monitor the diesel generator sets.

5. ordering requirements for diesel generator sets

Well above options, the ordering of the diesel generator set is generally shall be marked with the following:
(1) unit model, rated power, rated frequency, rated voltage, rated current, phase, power factor and wiring methods.
(2) the unit automation functionality and performance requirements.
(3) requirements for diesel engines, generators and control structure of the screen, performance, installation dimensions.
(4) units operating in parallel requirements: the purchase of multiple units, and whether it requires parallel, such as the need parallel should be asked whether we need to provide parallel required measuring instruments and devices.
(5) ancillary equipment for the unit requirements: many domestic manufacturers of cooling water tank (radiator), fuel tank, exhaust muffler, battery to be regarded as ancillary equipment, allow to be put in order the installation of some of the requirements.

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