As a backup power source for data centers, diesel generator sets are an important force for data centers to deal with natural disasters such as typhoons and earthquakes. In order to ensure the normal use of the data center diesel generator set, it is necessary to debug and accept it before putting it into operation. Only after strict technical acceptance, when the performance indicators such as safety, power characteristics, power quality, noise, etc. reach the standard, the diesel generator set can be put into normal use.
First, the acceptance of the unit installation quality
The installation quality of the unit must meet the installation requirements of the diesel generator set. The diesel generator set should be considered during installation: the load of the foundation, the position of the walkway and maintenance, the vibration of the unit, the ventilation and heat dissipation, the connection of the exhaust pipe, the heat insulation, and the lowering. Main factors such as noise, fuel tank size and location, and related national and local buildings, environmental regulations and standards. When the installation quality of the unit is checked and accepted, it shall be checked and accepted according to the installation requirements of the unit and the design requirements of the equipment room.
1. The principle of the arrangement of the unit in the machine room
(1) The intake and exhaust ducts and the exhaust ducts shall be laid overhead on the sides of the unit against the wall, and the height shall be 2.2m or more. The exhaust ducts shall be arranged on the back of the unit.
(2) The installation, inspection and handling of the unit should be arranged on the operating surface of the unit in a parallel machine room. In a parallel-arranged machine room, the cylinders are erected single-row units, generally arranged at one end of the diesel engine, while for a V-shaped diesel generator set, they are generally arranged at one end of the generator. For two-row parallel machine rooms, the installation, maintenance and handling of the unit should be arranged between the two rows of units.
(3) The height of the machine room should be the height required to lift the piston, connecting rod and crankshaft through the manual hoist when the unit is installed and inspected.
(4) Cables, cooling water and fuel pipes should be placed on the brackets in the trenches on both sides of the unit. The net depth of the trenches is generally 0.5-0.8m.
2, the architectural design requirements of the machine room
(1) The equipment room should have access, passage and door holes for transportation of large-scale equipment such as diesel generator sets and control panels, which is convenient for equipment installation and transportation.
(2) Two or three lifting hooks shall be reserved above the longitudinal centerline of the unit, and the height shall be capable of lifting the piston and connecting rod assembly of the diesel engine for installation and maintenance of the unit.
(3) The pipelines for laying cables, cooling water and fuel in the equipment room should have a certain slope to facilitate the accumulation of water. The cover of the trench should be made of steel plate cover, reinforced concrete cover or fire-treated wooden cover.
(4) For the machine room where the control room is installed, an observation hole shall be provided in the partition wall of the control room and the machine room.
(5) For the equipment room designed together with the main building, sound insulation and noise reduction should be carried out.
(6) The ground of the machine room should be calendered concrete floor, or terrazzo or clinker floor. The ground should prevent oil from seeping in.
(7) Certain damping and isolation measures should be taken between the foundation of the unit and the surrounding ground and between the units to reduce the damage caused by vibration. The surface of the foundation with a common chassis should be 50 to 100 mm above the ground and protected against oil immersion. Sewage grooves and floor drains shall be provided on the surface of the foundation to remove oil from the surface of the foundation.
3. Installation requirements for fixed units
(1) Installation location: The generator set can be installed in the basement, ground and roof. The engine room of the generator set should be near the power distribution room for wiring, use and maintenance. However, it should not be too close to the communication equipment room to avoid the vibration, noise and pollution generated by the unit during operation affecting the communication effect of the communication equipment.
(2) Machine room and foundation construction requirements: The construction of the engine room should consider the power of the diesel generator set and the future expansion. It has a complete water supply and drainage system, and the construction should be firm, safe, and set up ventilation and heat dissipation channels. With lighting, insulation and fire protection measures. The temperature of the equipment room should be between 10 ° C (winter) and 30 ° C (summer). Heating and air conditioning are preferred for heating and cooling in the equipment room. For the diesel generator room in the office and living areas, shock absorption, noise reduction and exhaust purification devices must be used to protect the surrounding environment. The depth and length and width of the foundation should be determined according to the power and weight of the unit and the condition of the soil. The general depth is 500-1000mm, the length and width are not less than the base size of the unit, the foundation requirements are good, and the shock absorption capacity is available. .
(3) Fixing of the unit: The anchor bolts of the diesel generator set should be firmly grounded on the concrete foundation. The anchor bolts should be laid flat and firm to facilitate the operation and maintenance of the unit. The equipment should be arranged to meet the operation, maintenance, lifting and handling of the unit. And try to reduce the length of the pipeline to avoid pipeline crossing.
Second, the unit commissioning
1. Preparation for commissioning
(1) Debugging environment check
The debugging environment should be clean and tidy, free from dust and debris. The smoke exhaust, oil drain and water pipe of the unit should be smooth.
(2) Test equipment inspection
The functional integrity of the test equipment should be carefully checked before the test. For the test load, unit start power supply, line breaking switch, etc., it should be checked whether the line connection is reliable, whether the function is intact, whether the various instrument instruments used in the test meet the accuracy and validity period specified by the corresponding test level, and its function The status is good.
(3) The product drawings and technical data of the test unit should be carefully familiar and familiar with the test specifications of the unit.
(4) Add the coolant to the unit, add the oil, and turn on the fuel. Select the appropriate coolant according to different engines and regions, open the radiator cover of the unit and add the coolant to the MAX scale of the tank. Select the appropriate type of lubricant, open the engine oil filler port and add the oil to the machine to the appropriate position.
2. Quality inspection before the unit is turned on
According to the order of radiator, oil machine, control panel, generator, chassis and power distribution cabinet, the appearance quality of the unit is checked one by one, including welding quality, wiring quality, three leakage conditions, component quality and overall quality.
(1) Welding quality
The welding of the unit should be firm, the weld should be uniform, and there should be no defects such as welding, undercut, slag inclusion and pores. The welding slag and flux should be cleaned, and the paint film of the painted part should be uniform without obvious cracks and falling off.
(2) Wiring quality
The connections are in good contact, the fastening is firm, the signs are clear, and the connections are correct. The electrical installation of the unit should be in accordance with the circuit diagram. The phase sequence of the terminal block of the unit control panel should be arranged from left to right or top to bottom from the front of the screen. The connection of each line should have obvious signs that are not easy to fall off. The signs such as nameplate, direction sign, grounding card, etc. are firmly set, the content is clear and accurate, and the grounding terminal is well set. The unit nameplate should include the following:
a. crew name;
b. unit model;
c. the number of phases;
d. rated speed, r / min;
e. rated frequency, Hz;
f. rated power, KW;
g. rated voltage, V;
h. rated current;
I. Rated power factor;
j.Quality, Kg;
k. name of the manufacturer;
l. unit number;
m. date of manufacture;
n. Standard code and number.
(3) Three leaks
The unit should be free of oil leakage, water leakage, and air leakage (check after power on).
(4) Parts quality
Diesel engines, generators, control panels, power distribution cabinets and other components and parts should be intact, no obvious scratches or cracks on the surface, no damage to the control panel and clean surface.
(5) Overall quality
The components are fixed and connected reliably, and the whole machine has no missing parts, no missing nuts and washers. There should be no debris or metal objects inside the unit, especially the control panel and the power distribution cabinet.
(6) The minimum distance between the exposed phase conductors and the conductors in the equipment junction box shall meet the insulation requirements of different voltage levels. Otherwise, insulation protection measures shall be taken.
(7) If the switchgear, automatic or manual switching device and protection device of the power distribution cabinet pass the test, the load test shall be carried out according to the designed self-supplied power supply distribution plan. The grounding or zero connection of the bare conductor for grounding shall be reliable.
(8) Measuring insulation resistance
Measure the insulation resistance between the individual electrical circuits and the ground, and measure with a megger (see Table 1 for specifications). Semiconductor devices, capacitors, etc. should be removed during measurement, and each switch should be in the on position. When the megohmmeter indicates stability, read it again, and record the ambient temperature and relative humidity of the air. The test results should meet the requirements of Table 2.
Table 1
Rated voltage of the circuit under test /V
|
Megohm specification/V
|
Lower than 100
|
250
|
100~500
|
500
|
500~3000
|
1000
|
Higher than 3000
|
2500
|
Table 2
Conditions
|
Circuit rated voltage (V)
|
≤230
|
400
|
6300
|
10.5kV
|
Cold Insulation Resistance (MΩ)
|
Ambient temperature (15 ~ 35) ° C, air relative humidity is 45% ~ 75%
|
2
|
2
|
AMC
|
AMC
|
The ambient temperature is 25 ° C, the relative humidity of the air is 95%
|
0.3
|
0.4
|
6.3
|
10.5
|
Thermal insulation resistance (MΩ)
|
0.3
|
0.4
|
6.3
|
10.5
|
(9) Insulation dielectric strength test
This test is conducted to test the dielectric strength between the individual electrical circuits and the ground. During the test, the power is turned on and increased to the full value evenly or in sections of 5% of the voltage not exceeding the full value. The time from the increase of the half value to the full value of the voltage should not be shorter than 10S, and the full-value voltage test lasts for 1 minute. Then start to step down, wait for the voltage to drop to one-third of the full value, then cut off the power, and discharge the circuit under test to the ground. Record the ambient temperature air relative temperature, atmospheric pressure, test results should meet the relevant provisions of GB/T2820 (the specific test voltage values are shown in Table 3).
Table 3
Parts
|
Circuit rated voltage (V)
|
Test voltage (V)
|
One loop to ground, one loop to the secondary loop
|
>100
|
(1000+2 times rated voltage) X80%, minimum 1200
|
Secondary loop to ground
|
<100
|
750
|
Note: The electrical part of the engine, semiconductor devices and capacitors are not tested
|
After passing the above test, it can be transferred to the start-up test.
Third, the acceptance of the unit performance indicators
The acceptance criteria for generator set performance indicators are recommended to use the G3 standard in the performance class and operating limits of the GB/T 2820.5 generator set.
1, check the normal temperature start performance
In the normal temperature and cold state, the unit's starting device is used to start the unit three times according to the method specified in the instructions. The interval between the two starts should be 10~30s, and the ambient temperature, relative humidity, atmospheric pressure and oil temperature should be recorded. , number of starts, and start time. Check the results, the start should be successful. If it is equipped with a low-temperature start-up measure, it should be inspected, and the circuit, pipeline, oil circuit, etc. should be smooth and work properly.
2, check the phase sequence
Check the output of the generator and control panel with the phase sequence indicator. The result of the inspection should be consistent with the unit output mark.
3. Check the working status of each indicating device on the control panel
In the two states of no-load and rated negative at rated voltage, check whether the accuracy of each electrical measuring instrument on the control panel of the unit meets the requirements, and whether the signal devices are working properly. Record the operation of each electrical measuring instrument and signaling device, as well as ambient temperature, relative humidity of the air, and atmospheric pressure.
4, check the voltage setting range
At the rated power factor and rated frequency, the unit's output voltage can be adjusted from no-load to rated load. The adjustable range of the generator output voltage should not be less than ±5% of the rated voltage.
5, measuring frequency drop
(1) The unit is in a hot state, starting and setting the unit to operate under rated conditions;
(2) Record related stable counts;
(3) Reduce the load to no load, and record the stable frequency under wear, that is, the rated no-load frequency;
(4) Calculation formula:
Frequency drop: The frequency difference between the rated no-load frequency and the nominal frequency at the nominal power is determined by a certain percentage of the rated frequency δfst
under the conditions determined by the setting frequency.
Δfst=(fi,r-fr)/fr×100
Where: δfst - frequency drop;
Fi, r—rated no-load frequency in Hz;
Fr—rated frequency in Hz;
The test results should meet δfst ≤ 3%
6, measuring the steady-state frequency band
(1) The unit is in a hot state, starting and setting the unit to operate under rated conditions;
(2) Reduce the load to no load, gradually load from no load to 25%, 50%, 75%, 100% of the rated load, the power factor under all levels of load is the rated value, the voltage shall not be set;
(3) Record stable counts under load at all levels;
(4) Calculation formula:
Steady-state frequency band: The value of the envelope frequency around a certain average value at a constant power expressed as a percentage of the nominal frequency.
Ff=Δuf/Uf×100%
Where: βf—steady-state frequency band;
Δuf—the maximum value of the highest peak and the lowest valley difference of the voltage signal corresponding to the stable frequency signal under various loads, the voltage is V;
Uf — The rated frequency signal corresponds to the average amplitude of the voltage signal waveform, and the voltage is V
The test result should satisfy βf≤0.5%
7. Measure the transient frequency deviation (for the initial frequency) and the transient frequency deviation (for the rated frequency) by load increase (-) and load decrease (+) and frequency recovery time
(1) The unit is in a hot state, start and set the unit to operate stably under rated conditions, and then reduce the load to no load.
(2) Suddenly rated load----The unit sets the rated frequency and voltage to the rated voltage under no-load, gradually loads to the rated load, and the power factor is the rated value. After the operation is stable, the load is reduced to no-load, and then Repeat three times from no-load spike to rated load.
(3) Sudden reduction of rated load----The unit is stable under rated voltage, rated load, rated power factor and rated frequency. The rated load is reduced to no-load and repeated three times.
(4) Suddenly add the specified load----The unit sets the rated frequency under no-load, the voltage is the rated voltage, and gradually loads to the specified load, the power factor is the rated value. After the operation is stable, the load is reduced to no-load, and then Repeated from the no-load spike to the specified load, three times.
(5) Calculation formula of transient frequency deviation:
Load increase (-): δfdyn=(fd,min –fr)/ fr×100%
Load reduction (+): δfdyn=(fd,max –fr)/ fr×100%
Where: fd, min – minimum instantaneous drop (or undershoot) frequency in Hz;
Fd,max – the maximum instantaneous rise (or overshoot) frequency in Hz;
Fr – rated frequency in Hz
The measurement results should be satisfied:
Suddenly 50% load δfdyn ≤-7%
Unloading 100% load δfdyn≤+10%
Frequency recovery time ≤ 3s
8. Measuring steady-state voltage deviation
(1) The unit is in a hot state, and the unit is started and set to operate stably under rated conditions.
(2) Reduce the load to no load, gradually load from no-load to 25%, 50%, 75%, 100% of the rated load, and then reduce the load from 100% to no-load according to this level. The frequency and power factor under load at all levels are rated and the voltage must not be set.
(3) Calculation formula:
Steady-state voltage deviation: The maximum deviation from the set voltage under steady-state conditions that affect the temperature rise at rated frequency for the specified load between the no-load and rated output and at the specified power factor. The steady state voltage deviation is expressed as a percentage of the rated voltage.
δUst=±(Ust,max -Ust,min)/2 Ur×100%
Where: Ust,max ---- the highest steady-state voltage after the load is ramped, take the maximum value of each reading for the single camera group, and take the maximum value of the average value of the three-phase line voltage for the three-phase unit, the unit V; Br>
Ust,min ----The lowest steady-state voltage after the load is ramped, the minimum value of each reading for the single camera group, and the minimum value of the average value of the three-phase line voltage for the three-phase unit, the unit is V.
The measurement results should satisfy δUst ≤ ±1%.
9. Continuous operation test under rated conditions
(1) Requirements: The test is carried out under the condition that the unit is under rated working conditions. The continuous operation time is 12h for the conventional unit, including 110% rated power for 1h.
(2) Method: The unit is operated for 15 minutes at no load, followed by full load for 30 minutes. Record power, voltage, current, power factor, frequency, diesel engine cooling water temperature and oil temperature, ambient temperature, air relative humidity, and atmospheric pressure every 15 minutes. Note: If the unit is equipped with a module or digital display, the module must be guaranteed. Or the measurement readings on the digital display are consistent.
(3) Results There shall be no oil leakage, water leakage or abnormal air leakage during the rated operation time; the water temperature and oil temperature shall comply with the technical requirements of the product.
10, automatic start and automatic shutdown
(1) The unit should have heating means to ensure that the temperature of the oil and the temperature of the coolant are not lower than 15 °C during start-up and rapid loading.
(2) After receiving the self-control or remote control start command, the unit should be able to start automatically, and the output power after automatic start should reach more than 99%.
(3) After the unit fails to start 3 times, it should be able to issue a start failure signal. When a standby unit is provided, the program start system shall be able to automatically transmit the start command to the standby unit.
(4) The time from the receipt of the automatic start command to the supply of the load should not exceed 3 minutes.
(5) After the unit is automatically started, the first load cannot be lower than 50% of the calibration load.
(6) After receiving the automatic or remote control stop command, the unit should be able to stop automatically. For the standby unit that is switched with the mains, when the grid returns to normal power supply, the unit should be able to automatically switch to the mains supply and stop automatically. The stop mode and the stop delay time should meet the requirements of the technical specifications on the unit manual.
11, automatic protection
(1) Overspeed protection
Start the diesel generator set and transfer it to the ground at the rated speed. After the speed is increased to the set value, the unit will emit an audible and visual alarm signal and automatically stop, allowing the simulation test.
(2) High water temperature protection
When the unit is in operation, so that the cooling water temperature is higher than the set value, the unit will emit a light alarm signal and automatically stop, allowing the simulation test.
(3) Low oil pressure protection
When the unit is running, if the oil pressure is lower than the set value, the unit will emit an audible and visual alarm signal and automatically stop, allowing the simulation test.
(4) Over and under voltage protection
When the unit is in running state, its output voltage is higher or lower than the set value, the unit will emit an audible and visual alarm signal and stop automatically.
(5) Overload protection
When the unit is in the running state of rated load and the load is increased to exceed the set value, the unit will emit an audible and visual alarm signal and stop automatically.
12, unit noise
The average value of noise sound pressure at 1m from the unit is ≤108dB(A)
13, unit vibration
(1) Measuring equipment
One vibrometer.
The measurement points are shown in the figure below:
Figure 1 Diesel generator set test points
(2) Measurement procedure
1 The integrity of the unit under test meets the requirements of the factory qualified products.
2 Start and adjust the unit to measure under no-load and rated conditions.
3 Use the vibrometer to measure the vibration values of the unit along the horizontal, vertical and vertical directions.
4 Use the table to record the relevant values.
The test results should be satisfied: the engine single amplitude is <0.72mm; the generator single amplitude is <0.32mm
14, the unit is running in parallel (when required)
(1) Manual parallel:
1 start all units and carry out no-load parallel;
2 The no-load parallel machine is stable after 3 minutes, and each unit should distribute the active power and reactive power evenly;
3 One of the components of the machine shall be shut down and shut down, and other units shall distribute the load of the unit evenly;
4 In turn, the remaining components are gated and stopped until one unit remains. During this period, the load should be smoothly transferred and the unit load should be automatically divided (note that the load should be gradually reduced in this process to avoid overloading the unit);
5 Gradually reduce the load to 0, and brake, cool, and shut down the last 1 component.
(2) Automatic parallel connection:
1 All units will be in automatic state, and the unit will be controlled by external input signal;
2 All units are started, and no-load parallel connection;
3 After the operation is stable, the unit is loaded,
4 The unit enters the power management mode. When the load is less than 20% of the power of the online unit (adjustable adjustment), the unit with the lowest priority will be unloaded and stopped. Similarly, when the load is greater than 80% of the power of the online unit (the parameters can be set) When the delay is delayed, the generator set with high priority is not automatically started. After the unit starts to stabilize, it is automatically synchronized and closed, and the online generator set realizes soft loading and automatic load distribution.
(3) Technical requirements:
In the whole process, the active and reactive power distribution deviation between each unit is ≤±10%, and the load transfer between units should be stable.
15, system monitoring function (when required)
The monitoring touch screen of the genset system should be able to display the single line diagram of the genset system and the status of each circuit breaker, the electrical parameters of each unit operation, and can start, stop, close, open and other operations of each unit through the touch screen.
Fourth, summary
It is of great significance to implement the acceptance work of diesel generator sets for the safe and stable operation of diesel generator sets and reliable power supply, and to maximize the role of diesel power generation groups in data centers.
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