Parallel connection of diesel generator sets should first meet the requirements of even power distribution. The even distribution of power includes both active power and reactive power. The so-called uniform distribution means that the active power and reactive power of each generator should be proportional to their rated power. There are clear requirements for the power distribution of parallel-operated generator sets in China, when the alternator sets are operated in parallel. When the load changes within the range of 20% to 100% of the total rated power, it should be able to operate stably, and its power distribution error should meet the following requirements. 1. The difference between the actual active power of each generator and the calculated value according to the rated power ratio shall not exceed ±10% of the rated active power of the generator when the rated power of the generator is the same; when the rated power of the generator is different, Should not exceed 110% of the maximum rated active power of the generator, ±20% of the rated active power of the minimum generator. 2. The difference between the actual reactive power of each generator and the calculated value according to the ratio of rated power of the generator not exceeding the maximum generator amount If there is a large imbalance in power distribution, whether it is active power or reactive power, it will not only affect the efficiency and economy of the genset operation, but also cause the failure of the entire power station. If the active power distribution of the parallel generator set is seriously unbalanced, when the total load power is large, it is often that one generator set is fully loaded or overloaded, and the other generator is still under light load, so that it cannot be fully utilized. The capacity of the genset is used to make the performance of the entire power station. The overload of the genset will not only bring harm to the diesel engine or the generator, but also cause the protection equipment to operate and affect the operation of the entire power station. Conversely, when the total load power is small, the imbalance of active power tends to cause active circulation between the generator sets, causing some generator set to switch to the motor state, which is also not allowed for diesel engines. When the genset has reverse power protection, the reverse power phenomenon will cause the reverse power to trip causing a malfunction. For diesel power plans with frequent load changes and large variation, the above situation should be paid more attention. For example, in a diesel power station of a ship’s electric propulsion device, due to the uneven distribution of active load of the parallel generator, when the ship is sailing at full speed, the total load power is large, often overloading the heavy-duty generator, causing the switch then trips, causing a serious power failure. When the ship stops at the dock, the light load generator enters the reverse power state due to the small total load, causing the reverse power trip, which affects the reliability of the operation of the power station and even the entire ship. The above situation is sufficient to show that the even distribution of power between generators in parallel operation is not only a problem of economic operation of a generator, but also an important factor to ensure the reliability of power supply of the entire diesel engine power station. The reactive power distribution is uneven, although it will not seriously affect the diesel engine, but the rated value of the generator power is determined according to the apparent power, and the reactive power imbalance will inevitably cause the unbalanced apparent power of the generator. It will limit the capacity of the generator set, especially for power plants with lower power factor, the load capacity of the genset does not depend on the rated power of the diesel engine, but depends on the rated current value of the generator. The imbalance of the reactive load can also be regarded as a kind of ring between the two generators. The flow sometimes exceeds the load current of the generator and generates additional losses inside the generator. And even overload the generator. The reactive overcurrent also trips the generator’s main switch, causing a malfunction. In addition, the magnitude of the reactive current of the generator is consistent with its excitation current. The imbalance of the reactive current tends to occur at the same time as the excitation current imbalance, which causes the excitation system of overload or even cause failure, such as the rotor winding of the generator is burned/ the rectifier diode of the compound excitation device is damaged, etc., and the consequences of such failure are often quite serious. It can be seen that the uniform distribution of the reactive load and the uniform distribution of the active load have the same meaning.
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Diesel generator set correct shut down operation method Proper operation of diesel generator set shut down is one of the effective measures to prevent the occurrence of faults, and has direct protection for extending its service life. Let us introduce the correct shutdown operation method of diesel generator set. 1. Before stopping, first remove the load, then adjust the adjuster handle, gradually reduce the speed to about 750r/min, and then 3-5 minutes after the operation, then turn the stop handle to stop, try not to load the diesel generator set at full load as soon as possible. Stop to prevent accidents such as overhearing. 2. For a 12-cylinder V-type diesel engine, the electric key should be turned from left to intermediate position after shut down to prevent battery current from flowing back. When running in cold areas and need to stop, immediately open the drain valve on the side of the body, fresh water pump, oil cooler (or cooling water pipe) and radiator, and drain the cooling water to prevent freezing cracks. If you use antifreeze coolant, you do not need to open the drain valve. 3. For diesel engines that need to be stored for a long time, the last time the machine is shut down, the original oil should be drained, replaced with sealed oil, and then stored from about 2 minutes for sealing. If antifreeze coolant is used, it should also be released. 4. In case of emergency or special circumstances, in order to avoid serious accidents in the diesel engine, an emergency stop can be taken, and the emergency stop handle can be directly dialed. Precautions for the use of the emergency stop button of the diesel generator set The emergency stop button of the diesel generator set is a button that needs to be pressed when the generator set fails to stop normally when the generator set encounters a sudden situation or when there is an unexpected situation with the electric load. When the machine is stopped, it should be reset. It should be pressed for a long time. If it is pressed for a long time, it will definitely not start when the second should immediately press the emergency stop button? 1. The cooling water temperature or oil temperature rises sharply. 2. Oil pressure gauge pointer suddenly drops or no pressure. 3. Abnormal knocking sounds occurred in the operation of the diesel generator set, the flywheel was loose or the transmission mechanism was seriously abnormal. 4. The speed is automatically increased and there is a flying phenomenon. 5. A flammable and explosive latent accident occurred on the site of the diesel generator set. 6. The diesel line is broken, parts are damaged or moving parts such as piston and governors are stuck. What should be paid attention to when the generator set is shut down?
It is important to let the engine idle for 3 to 5 minutes before stopping, so that the lubricating oil and cooling water can take away heat from the combustion chamber, bearings and shafts. This is especially important for turbocharged engines. The bearings and oil seals in the turbocharger are subject to the high temperature of the exhaust. When the engine is running, this hear is taken away by the circulating oil, but if the engine suddenly stops, the supercharger temperature may rise by as much as 56 °C. the result of overhearing will cause the bearing to jam or the oil seal to fail.
Long idle operation is detrimental to the engine because the combustion chamber temperature is too low, making impossible for the fuel to burn completely. This will cause deposits that can clog the injector orifices and piston rings and may cause the valves to become stuck. If the temperature of the engine coolant becomes too low, some unburned diesel will flush the oil on the cylinder wall and dilute the oil in the crankcase, so that all moving parts in the engine are poorly lubricated. If the engine is not in use, it should be stopped. 3. Turn the key switch to the off position to turn off the engine For engines with electric shut-off valves, the engine can be completely shut down by turning off the key switch or by turning the manual valve. The key switch controls the electric shut-off valve. As long as the manual control knob on the shut-off valve is not locked in the open position, turning off the key switch always stops the engine. If you use the manual control knob on the electric shut-off valve, turn the knob counterclockwise to turn the engine off. The valve cannot be re-opened with the key switch before the engine is completely down. Note:never place the key switch or control knob in the open position or in the operating position when the engine is stopped. The high fuel tank will cause diesel to flow into the cylinder, causing hydraulic locking. 4. Stop any engine immediately if ant part is faulty. In fact, all faults always give the operator some warning before the part fails and the engine is damaged. Some alter and experienced operators noticed the alarm signal (a sudden drop in oil pressure, abnormal sound, etc.) and immediately stopped the engine, thus saving many engines. Diesel generator set pressure processing repair parts are the use of external force to plastically deform the metal, restore the geometry of the part, or move the metal of the non-working part of the part to the worn part to compensate for the worn metal and restore the original working surface of the part. Size and shape. According to the plasticity of metal materials, it is divided into two types: cold press processing at normal temperature and hot press processing under hot state. The following is a brief introduction to the repair of diesel generator sets - the upsetting method, the expansion method, and the reduction method in pressure processing. 1. It is a processing method that reduces the height of the part, increases the outer diameter of the part, or reduces the size of the inner diameter. Mainly used to repair non-ferrous metal sleeves and cylindrical parts. For example, when the inner diameter or outer diameter of the copper sleeve is worn, it is upset at a normal temperature by a special mold, and can be manually hammered using a press, a hand press or a hand hammer, and the direction of the force should be perpendicular to the direction of plastic deformation. , as shown in Figure 2-22. Repaired by upsetting, the shortening of the part after compression should not exceed 15% of its original height, and for larger loads it should not exceed 8% of its original height. In order to be thick and uniform, the ratio of height to diameter should not be greater than 2, otherwise this method should not be used. 2. The expansion method is a repair method that expands the aperture of the part, increases the outer diameter size, or expands the unimportant part of the metal to the worn part to restore the original size. For example, after the outer circumference of the hollow piston pin is worn, it is generally repaired with chrome plating. However, when there is no chrome plating equipment, it can be repaired by expansion method. The expansion of the piston pin can be carried out both in the hot state and in the cold state. Fig. 2-23(a) is a mold for expanding the piston pin 2 by the cylindrical punch 1. In order to facilitate the punching, put the end of the cone and arc transition. 4 is the mold base, 3 is the expansion and contraction sleeve, its function is to prevent the wall damage and uniform tension. Figure 2-23(b) shows the die of the tapered punch expansion piston pin, which has the same meaning as before. When the piston pin is in thermal expansion, it should be heated to 950~1000 °C and kept for 2~3h. At this temperature, it is immediately put into the mold and pressed on the press. Before the cold expansion. It should be heated to about 600 ° C and incubated for 1.5-2 h for annealing. After the piston pin is cooled, apply oil to the mold, and then put it on the press together with the mold to apply pressure. The expanded piston pin shall be heat treated according to technical requirements, and then the outer mesh shall be ground to meet the dimensional requirements. The expansion method is mainly applied to sleeve-shaped parts with outer diameter wear. 3. The reduction method is the opposite of the expansion method. It is a repair method that uses the die to squeeze the outer diameter to reduce the inner diameter. The outer diameter of the small sleeve can be repaired by metal spraying, copper plating or inserting. If the bushing is large, it can also be 3-4 copper rings on the outer diameter and then machined so that the inner and outer diameters meet the specified size requirements. The size of the tapered hole of the mold is determined by the plastic deformation of the part material and the amount of compression required. When the plastic deformation property is low and the compression amount is large, the taper of the taper hole of the mold may be 10 degrees to 20 degrees; when the value of the compression amount is small, the taper is 30 degrees to 40 degrees; for the material with high plastic deformation property The taper can be 60 degrees to 70 degrees. Diesel generator set parts often have residual deformation such as bending and twisting during use. The method of using external force or flame to make new plastic deformation of the part to eliminate the original deformation of the generator is called correction. The correction is divided into cold correction and thermal correction. 1. cold correction Cold correction can be divided into pressure correction and cold correction. (1)Pressure Correction Place the deformed part in the V-groove of the press with the convex surface facing up, press the part by pressure and bend it to 10~15 times. After 1~2min, remove the pressure and check the deformation. If you don't have a school, you can do it many times until you are straight. In order to stabilize the deformation after pressure correction and improve the rigidity of the part, a qualitative heat treatment is required after the correction. The pressure correction is easy, but the accuracy of the calibration is not easy to control, leaving a large residual stress in the part, the effect is unstable, and the fatigue strength is reduced. (2)Cold Work Correction Cold work correction is the use of a hammer to strike the convex surface of a part to cause plastic deformation. The metal of this portion is extruded and expanded to generate compressive stress in the plastically deformed layer. Think of this deformed layer as a compressed spring that has a thrust effect on the adjacent metal. The curved part is corrected by the deformation layer stress. The correction accuracy of the cold correction is easy to control, the effect is stable, and the qualitative heat treatment is generally not performed, and the fatigue strength of the parts is not lowered. However, it cannot correct parts that have too much distortion. Usually, the bending of the part cannot exceed 9.03%~0.05% of the length of the part. 2. Thermal correction Thermal correction generally involves rapidly heating the highest point of the curved portion of the diesel generator set to a gas-fired neutral flame to above 450 ° C and then rapidly cooling. As the metal of the heated portion expands, the plasticity increases with increasing temperature and, due to the hindrance of the surrounding cold metal, may stretch as the temperature increases. When cooled, the amount of shrinkage is proportional to the magnitude of the temperature drop, causing the amount of shrinkage to be greater than the amount of expansion, and the shrinkage force is large, relying on it to correct the deformation of the part. When heat correction, the larger the diesel generator set parts are bent, the higher the heating temperature. The ability to correct the bending deformation increases as the heating area increases, and the heating area can be determined according to the deformation condition during the correction. As the heating depth increases, the ability to correct the deformation also increases. When the heating depth is increased to 1/3 of the thickness of the part, the correction effect is better. However, the heating depth continues to increase, the correction effect will be reduced, and all parts of the heat will not be corrected. In the calibration process, the heating depth is mainly determined by experience, and the parts must not be thermally permeable, and cooling measures should be taken if necessary. The thermal correction is suitable for correcting large-size parts with large deformation and complex shapes, good correction and retention, little influence on fatigue strength, and application is common. For parts with higher requirements, flaw detection must be carried out after calibration. If cracks are found, measures should be taken to repair or scrap. Calibration can be performed on the press or with special tools or hand hammers. Difference Between Diesel Generator and Gasoline Generators Although diesel generators and gasoline generators are used for emergency power generation, they work differently except for the name and oil. The diesel generator is a diesel engine that drives the generator to convert the energy of the diesel into electrical energy. The gasoline generator is a gasoline engine that drives the generator to convert the energy of the gasoline into electrical energy. The following is a detailed introduction to the difference between the two. Working principle of diesel generator In the cylinder of the diesel engine, the clean air filtered by the air filter is fully mixed with the high pressure atomized diesel fuel injected from the injector. Under the upward extrusion of the piston, the volume is reduced and the temperature is rapidly increased to reach the ignition point of the diesel. The diesel is ignited, the mixed gas burns violently, the volume expands rapidly, and the piston is pushed down, which is called work. Each cylinder performs work in a certain order, and the thrust acting on the piston passes through the connecting rod to become a force that pushes the crankshaft to rotate, thereby driving the crankshaft to rotate. Working principle of gasoline generator In the cylinder of the gasoline engine, the mixed gas burns violently, and the volume expands rapidly pushing the piston to work downward. Each cylinder performs work in a certain order, and the thrust acting on the piston passes through the connecting rod to become a force that pushes the crankshaft to rotate, thereby driving the crankshaft to rotate. By installing the brushless synchronous alternator coaxially with the gasoline engine crankshaft, the rotor of the generator can be driven by the rotation of the gasoline engine. By using the principle of "electromagnetic induction", the generator will output an induced electromotive force, and a current can be generated through the closed load circuit. . It can be seen from the above that in the diesel engine, the mixture is compressed into heat, and the mixing of fuel and air in the cylinder of the gasoline engine is marked with a spark plug; diesel is less volatile than gasoline, and has a larger gallon per gallon. The calorific value, that is, 5dm3 diesel can obtain more power than 5dm3 gasoline; in the diesel engine, the mixture of diesel and air is carried out after the diesel is injected into the cylinder, while in the gasoline engine, the fuel and air are in the carburetor and the intake Mixed in the pipeline. Since the mixing must be immediately after the fuel eruption, the diesel generator needs to have a specially planned combustion chamber to facilitate the mixing of diesel and air. Therefore, the planning and production of the combustion chamber is very important for diesel generators. The difference between diesel generator sets and gasoline generator sets The difference between a diesel generator set and a gasoline generator set is mainly due to the different performance of its diesel engine and gasoline engine. 1. The type of fuel Diesel is a fuel that is less volatile than gasoline, and has a large calorific value per liter of diesel. 2. The type of ignition In the cylinder of a gasoline engine, a mixture of fuel and air is ignited with a spark plug. In a diesel engine, the mixture is ignited by the heat generated by compression. 3. Mixing of fuel and air. In a gasoline engine, fuel and air are mixed in a carburetor and an intake duct. In a diesel engine, the mixing of fuel and air is performed after the diesel is drawn into the cylinder. 4. The output power of a diesel generator is much larger than the output power of a gasoline generator set. The average power of a typical gasoline generator set is only 10KW, while the minimum power of a diesel generator set is 8KW. 5. Gasoline generator sets are small in size. The movement is convenient, and the diesel generator set is bulky and inconvenient to move. What are the advantages of diesel generator sets compared to gasoline generator sets? There are many models in the generator set, and the power is different. Most of the large and medium-sized generator sets are fueled by diesel. The generators with smaller power are generally fueled by gasoline. So what are the advantages of a diesel generator set with a diesel engine and a gasoline generator set with a gasoline engine as a generator power source? 1. Fuel consumption The diesel engine has high thermal efficiency, low fuel consumption rate, and the fuel pump rate curve changes relatively flat when the working conditions change, which is very important for diesel engines that often work under partial load. 2. Reliable and durable work Since there is no ignition system the diesel engine, the fault is relatively small and the work reliability is high. 3. Wide range of use 4. Lees harmful emissions 5. Good fire safety How the Fuel Regulating System of Diesel Generator Set Works The fuel speed control system is the main component of the diesel engine. It consists of oil pump, fuel filter, fuel injection pump, governor, fuel injector, high pressure oil pipe oil return pipe. The oil pump sucks the fuel from the fuel tank and sends it to the fuel filter. After filtering, it enters the fuel injection pump. After the fuel pressure of the fuel injection pump is increased, the fuel supply amount required by the same working condition is sent to the high pressure oil pipe. The injector is finally sprayed into the combustion chamber through the nozzle of the injector. In order to maintain the appearance and surrounding fuel cleaning of the diesel engine, a small amount of fuel flowing out of the fuel return pipe from the side of the injector should be returned to the fuel tank by the user. The reliability of the operation of the fuel speed control system directly affects the performance of the diesel engine. Therefore, whether it is in operation, disassembly and repair, installation or in test adjustment, the most important thing is to keep it clean. This is the first condition for ensuring quality. The governor used in the Randy series diesel engine is divided into two types, one is the electronic governor, which includes the following parts: (a) speed sensor (b) electromagnetic actuator (c) speed thrower, and control and switches, connecting cables and other accessories. The rotational speed sensor is installed above the flywheel housing of the diesel engine, the rotational speed signal is transmitted from the diesel flywheel ring gear, and the electromagnetic actuator is installed at the rear end of the high pressure oil pump. The speed controller and the connecting cable are placed or installed in the diesel monitor box by the user. Its high and low speed conversion, parking switch (power switch) is available at random. The power supply of the electronic governor, which can significantly improve the speed regulation performance of the diesel engine. Its steady state speed regulation is not more than 3%, and the speed fluctuation value is small, which can fully meet the technical requirements of the power station. When the diesel engine was tested in the factory, the parameters of the speed controller of the electronic speed control system were correctly adjusted, and the low speed setting and high speed setting were painted and sealed, and the user could not adjust it arbitrarily. If the user needs emergency stop due to special circumstances, the diesel engine equipped with electronic governor can turn off the power switch of the electronic governor (that is, the parking switch of the diesel engine) to cut off the power supply of the electronic governor and achieve emergency stop. The mechanical centrifugal full program has high-speed limit screws on the operating mechanism. The diesel engine has been adjusted and sealed before leaving the factory. The user can unpack it without the permission of the factory professional, otherwise the product will not be listed into the product quality three packs of service. A parking handle is also installed on the front of the governor for emergency parking. A low-speed stabilizer is also installed on the governor housing to prevent low-speed instability of the diesel engine. When the diesel engine is stable at low speed, the low speed stabilizer can be slowly screwed in until the speed is stable (the normal speed fluctuation is within the range of ±25/min) and then fixed. All factory diesel engines have been adjusted, and users should not pull them when necessary. If the fuel pump and governor are disassembled and repaired, and the diesel engine is unstable, the user can adjust it by himself. However, it must be noted that the low speed stabilizer can not be screwed in too much, so as to avoid excessive speed of the empty car and cause an accident. The steel plate coupling is connected between the high pressure oil pump and the drive shaft of the lattice series coupling is connected between the high pressure oil pump and the drive shaft of the transmission system. In order to ensure the reliable operation of the steel plate coupling and avoid the steel plate breakage accident in the device caused by the installation and use, the user should pay special attention to the following items when changing or adjusting the steel plate coupling parts. First, the steel plate coupling is placed on the drive shaft of the fuel injection pump, so that the shaft can be axially moved, then the bolt D (2 pieces) is loosened, and the rear end of the steel plate glaze is bolted A (2 pieces) Tightening on the diesel fuel injection pump disc, the final tightening torque of bolt A is 40N 'm, and then tighten the bolt D (2 pieces) on the steel plate coupling. The tightening torque of bolt D is 40N 'm, then adjust the steel. The axial position of the plate coupling ensures that the steel sheet must not be flexed, and then tighten the bolt B (1 piece) with a tightening torque of 40N. m~50N. m, the steel plate coupling and the fuel injection pump drive shaft are reliably tightened, and finally the 蠓 bolt C (2 pieces) is loosened, the diesel fuel supply advance angle is adjusted within the specified range, and the bolt C (2 pieces) is tightened to 40N. 'm, the installation work of the steel plate coupling is completed. How to Judge the Working State of Diesel Generator Set by Sound Diesel generator set belongs to mechanical equipment and is prone to malfunction during long working hours. The common method of judging fault is listening, looking, checking, among which, the most effective and direct method is to judge by the sound of generator, and can eliminate the small fault by sound, in order to avoid the occurrence of major fault. Below shows you how to judge the working state of diesel generator set from the sound. 1. When the diesel engine running at low speed (idle speed) of the diesel generator st, the metal tapping sound of “blah, blah” can be heard obviously by the valve cover. The sound was caused by an impact between the valve and the rocker arm, mainly because the valve gap was too large. The valve clearance is too large or too small, the diesel engine can not work properly. The gap between the valve and the valve is too large, the displacement between the rocker arm and the valve is too large, and the impact force caused by the contact is also greater, so that the metal knock sound is issued. This sound often occurs after long hours of work, so the valve clearance should be readjusted for every 300 hours or so of work. 2. When the diesel engine of diesel generator sets suddenly drops from high speed to low speed, the sound of “when, when” can be heard clearly in the upper part of the cylinder. This is one of the common problems with diesel engines. This main reason is that the gap between the connecting rod bushings is too large, and a lateral dynamic imbalance caused by the sudden change in the speed of the machine causes the piston pin to swing to the left and the right while rotating in the connecting rod bushing. The sound of a piston pin striking the bushing of a connecting rod. In order to avoid more trouble and cause unnecessary waste and economic loss, the piston pin and connecting rod bushing should be replaced in time to ensure that the diesel engine can work normally and effectively. 3. The diesel engine of a diesel generator set can hear a heavy, dull knock at the lower part of the diesel engine block. This noise becomes more pronounced especially when the diesel engine is working at high load. The sound is caused by abnormal friction between the crankshaft spindle bush or crankshaft spindle bearing and the main journal, mainly because the gap between the crankshaft spindle bearing and the spindle bush or crankshaft bearing is too large. This heavy, blunt knock, which results in uneven wear between the spindle neck and the crankshaft spindle bearing or bearing, resulting in abnormal friction. The work of the diesel generator set should be stopped immediately after the sound is heard, because if the sound is heard, the diesel generator set will continue to work without inspection and maintenance, and the phenomenon of "holding the tile" and "burning the shaft" is likely to occur. In order to avoid such a serious accident, the work should be stopped immediately to see if the spindle tile bolt is loose. If the crankshaft and spindle bearing or bearing should not be removed immediately, measured by a professional, the clearance between them shall be calculated and compared with the prescribed data, and the wear of the spindle and tile shaft shall be checked at the same time, Repair or replacement shall be given if necessary. 4. In the upper part of the cylinder, the engine can clearly hear a clear sound of the piston beating the cylinder block, which is often referred to as the "knock cylinder." The root cause of this failure is that the injection advance angle of the diesel engine is too small. As we all know, the fuel supply advance angle of diesel engine is one of the main technical data of diesel engine. Whether the fuel supply advance angle is correct or not will directly affect whether the diesel engine can work normally and whether the engine can provide normal power. Affect the working condition of the whole machine. In order to make the mixture formation and combustion process can be carried out normally, the diesel engine must have a certain injection advance angle, the injection advance angle is too small, and the air injected into the cylinder forms combustible gas combustion, which leads to unstable combustion. In the upward stage of the piston, the lateral deviation collides with the cylinder wall, and the knock on the cylinder body produces the sound of the cylinder knocking. 5. The diesel engine can hear a blunt-mute sound near the engine block while changing the load suddenly. This mainly comes from the abnormal friction between the crankshaft connecting rod journal and the connecting rod bush. The main reason is that the gap between the connecting rod journal and the connecting rod bush is too large, resulting in local runout. The mechanism of producing this sound and the method of maintenance detection are identical to those of spindle and spindle bush, so it is not introduced in detail here. 6. In the front cover of the diesel engine, a kind of "howling" sound can be clearly heard. This sound comes from the meshing gear inside the front cover, and the gear wear in each part of the meshing gear is excessive, which causes the clearance of the gear to be too large, so that the gear cannot enter the normal meshing state to produce this sound. The exclusion method is to open the front cover. Check gear meshing with lead sheet or paint and adjust. If gear clearance is too large, new gear must be replaced in time. 7. On the full length of the cylinder of a diesel engine, the mute sound can be heard, especially when the engine runs at a low speed or changes in speed. This phenomenon is mainly caused by excessive wear between the piston and the cylinder, which makes the gap between the piston and the cylinder too large. When the piston is up or down, the piston moves sideways inside the cylinder and oscillates, and when in contact with the cylinder wall, the wear is aggravated. Make the mute sound of friction. After this phenomenon, a professional technician should be found to identify the cylinder liner and piston, and replace the new piston or cylinder liner if necessary. 8. The sound of hammering anvil is similar to the sound of the diesel engine cylinder along the diesel generator set. The main reason for this sound is that the gap between the piston ring and the ring groove is too large, which makes the piston ring strike with the piston when it is running up and down, thus producing a sound similar to that of tapping the anvil with a small hammer. Once this happens, the engine should stop working and replace the new piston ring. 9. The sound of an object colliding can be heard at the top of the cylinder. At the same time as the sound reduces the valve gap, the impact sound also increases. The main reason for this sound of generator set is the collision between the valve and the piston. The main reason for this phenomenon is that the valve gap is not suitable. When the valve is running up to the top of the piston, the valve and the piston have a strong impact at high speed. At this time, the diesel engine is unable to work, and the anti-load ability of the machinery is obviously decreased. The concrete method of eliminating this kind of malfunction is to raise the piston of each cylinder to the top and stop point in order, press the valve down, check the gap between the piston and valve, and readjust the valve. How to Start And Stop Diesel Generator Set The following procedures are applicable for the initial start of the electric generating set configured with automatic start control system or the first start after a period maintenance of the generating set. Notice: *Press the emergency button or switch the control switch to “STOP” to stop the engine at any time. *Before restart, release the emergency stop button and rotate clockwise. Meanwhile, switch the control switch manually to “STOP”. 1. Examine before start the machine according to Chapter 5.2 2. Connect battery to the engine, first positive electrode and then load. 3. Check whether the engine oil is filled to the assigned level. 4. Check whether water is filled. 5. Discharge the air in fuel system. ! Connect and start the abnormal fueling system will cause unburned oil accumulated in the smoke evacuation system, bringing potential explosion risk. 4.Fill the fuel supply system with manual fuel tank and discharge the air accumulated in the oil filter. (For more detail information, please refer to the “Diesel Manual”) Start:Put the main controller to start position manually and press the start button. The diesel will automatically start for three times until started. If failed to start, the control system will lock at “starting failure” while the fault indicator on the control panel will be on. Under this condition, please refer to the “Diesel Manual” to find out the reason of starting failure. !If failed to start for many times, dismount the connector of the smoke evacuation pipe to disperse the unburned oil gas. Once the oil gas (white smog) dispersed and other faults for starting failure are rejected, reinstall the exhaust pipe and restart. 6.Check whether there’s unusual noise or vibration. 7.Check the cooling liquid and smoke evacuation system for leakage. 8. Check the control panel indicator lights for abnormality, especially for unusual high temperature or extremely low oil pressure. The oil pressure shall be in normal range 10s after the starting. 9.Check the voltage and frequency displayed on control panel. Voltage is the indicating rated voltage set by the factory and the load frequency of generating set with 50 cyclic waves is about 52 cyclic waves and 62 cyclic waves for generating set with 60 cyclic waves. (Electronic governor or cyclic wave of EFI unit can be pre-set an ideal value close to the rated cyclic wave.) There are three ways for voltage adjustment: if the control panel installed with voltage adjustment potentiometer, voltage can be adjusted through it; fine adjustment can be achieved through a potentiometer installed in the automatic voltage adjuster in the terminal box of alternator; output voltage alternation requires to change the coil of alternator with the coil joint stored in the terminal box. For more information on connection, please refer to the “Alternator Manual” ! Cutoff switch is not allowed to switch on during the phase examination. 10.When the electric generator already produced voltage, install the phase meter on one side of the cut off switch of the generator for phase examination, which shall be implemented by qualified technicians. 11.Stop diesel generator set:If press the emergency stop button, the machine will stop running immediately. If press the manual stop button, the machine will stop according to the set procedures. 12.Check the remote control device, release the emergency stop button and put the controller on “AUTO” Input the remote control signal and the engine will start according to the abovementioned procedures. Clear the remote control signal and the engine will stop immediately. Notice:When receive stop order, control system will control the engine to run continuously for a while depending on the cooling time before the automatic stop for the purpose of cooling. 13.Now the load cable can be connected and the generator is ready for normal operation. 5.4Normal manual start / stop------Automatic start control panel (normal start and stop) Notice: * Press the emergency stop button and the generator will stop at any time. * The emergency stop button shall be reset by clockwise rotation before restart. 1.Examine before start according to the description in Chapter 5.2. Notice: * It is not allowed to start the machine when the fault indicator light is on. Turn off the controller again and reconnect to the power switch for entering into a start procedure. Make sure all faults cleared before start. 2.Manual start: Make sure the emergency stop button reset. Put the manual button of controller to manual position and press the start button, releasing it when the indicator light above the start button is on. At this moment, controller enters into starting procedure and diesel will automatic start for 3 times until started. If the diesel failed to start, controller will display “starting failure” and fault indicator light on the control panel will be on. Under this condition, please refer to the 9th section to find out the fault or refer to refer to the “Diesel Manual” to find out the reason of starting failure. The unburned oil gas accumulated in the smoke evacuation pipe caused by many times starting failures is of explosive danger. Therefore, first disconnect the joint or pipe of the exhaust pipeline to let the white oil smog disperse, and find out the starting failure faults, and then reinstall the exhaust pipeline for restart. 10.1 Principle of battery 10.1.1 General description: battery is the combination of many battery individuals, including a lot of sheet metals and electrolyte solution. The electric energy is generated by the chemical reaction in battery. The chemical reaction is reversible. Therefore, it indicates the battery can be charged and discharged repeatedly. 10.1.2 Electrolyte solution: these conductive liquids can be called as electrolyte liquid. In an aluminic acid battery, it is the diluted sulfuric acid solution. It makes the sheet metals generate chemical reactions and become conductive media. 10.1.3 Proportion: proportion is the unit of measurement, used to decide the concentration of sulfuric acid in the electrolyte solution. It compares the weight of electrolyte solution to that of the water. When the battery discharges, the chemical reaction shall reduce the proportion of sulphurous acid in the electrolyte solution. Therefore, this measurement can be seen as the guidance for charging battery. 10.1.4 Aerometer: it can be directly used to measure the proportion. This device is a spherical pipette, which is used to pump out the electrolyte solution from the battery drum to mark the proportion in the graduated scale of the glass buoy in the column of the aerometer. Don’t measure the proportion of battery after adding the water into it. The battery should be charged to make water mix with the sedimentary sulfuric acid. The proportion measured in this way is reliable. More, if the value of battery is measured after it is controlled by the starting machine for a long time, its value will also be higher than its actual value. The water formed by the electrical machine during the process of fast discharging will have mixture of electrolyte solution in terms of time and electrical machine. 10.1.5 High or low temperature: a fully charged batter with proportion of 1.240 shall be used in the tropical climate (often higher than 32℃). The electrolyte solution with this medium intensity prolongs the service life of battery. If the battery is used in the low temperature environment, it will have sufficient power to supply for genset start-up for the concentration of sulfuric acid solution is low. But under this circumstance, it will not appear in the tropical climate. The stronger electrolyte solution shall be used for the battery used in the gelid climate. Under certain circumstances, if the proportion of 1.290-1.300 is adopted and when the proportion increases, the capacity for cold start will also be increased. 10.1.6 Temperature calibration: the scale of the aerometer is calibrated at 25℃. The proportion of the electrolyte solution is calibrated as the temperature is higher or lower than the aforementioned reference temperature. The reading increases by 0.004 when the temperature rises 5.5℃ as the reading decreases by 0.004 when the temperature falls by 5.5℃. 10.2 Maintenance of Battery In case of maintenance and repair, the operator shall wear acid proof apron, mask as well as protective glasses. Once the electrolyte solution sprinkles on the clothes and skin, it should be cleansed with a lot of clean water promptly. 10.2.1 Infuse electrolyte solution: the battery is dry during transportation. Therefore, it needs to add the correctly proportionally mixed electrolyte solution. Infuse it into each battery until the solution is higher than the top edge of the spitted sheet metal after removing the plug. It is necessary to have the battery stayed for 15 minutes. Check and adjust the water level if necessary. 10.2.2 Charging for the first time: the battery should be charged for 4 hours within 1 hour after the electrolyte solution is infused. It shall be performed according to the following currents, the electrolyte solution in the battery is fully mixed. Provided that the charging time is not sufficient, the capacity of battery will be damaged. As for the E017 battery, charging current is 9AMPS; As for E312, the charging current is 14AMPS; As for E324, the charging current is 20AMPS. If the charging time is longer than 4 hours, it will prolong in such following ways: if the battery is stored for more than 3 months, or the temperature exceeds 30℃ or higher than 80% of 8 charging hours; if the batter is stored for more than 1 year, 12 hours shall be used for charging. If the current output of charger is not sufficient, then, the low current can be used. But it can not be lower than 1/3 of the aforementioned currents and time is prolonged according proportion (8-hour 7AMPS instead of 4-hour 14AMPS). At the end of the charging time, it is necessary to check the water level of the electrolyte solution. The correct proportional sulphurous acid electrolyte solution can be added if necessary. The exhaust plug shall be placed back to the original position. 10.2.3: Liquid addition: normal operation and charging will cause some water evaporates, thus it is required to add the liquid to the batter from time to time. Firstly, the battery shall be cleansed to prevent the sewage from falling into, and then remove the exhaust plug. Firstly add distilled water, and then put it back to the exhaust plug until it is higher the edge of the partition of the sheet metal by 8MM (5/16). 10.3 Charging battery Make sure the battery is charged in the environment with good ventilation and there should be no sparkle and open fire. Don’t charge the battery in the environment, in which the wind and rain can be withstood. Don’t charge the battery nearby water. Do remember disconnecting the charger before dismantling the joint. The static (electric supply) charger can be used to charge the battery. Then it is necessary to disconnect the battery from the generator set and use another charger to charge it. In order to make users know more about the speed controller of diesel generator set, this paper introduces the working principle and wiring diagram of the speed controller. Basic Electrical characteristics of rotational Speed Controller Power supply voltage: DC24V (range 16V-32V) Power consumption: <0.1A (excluding actuators) Speed fluctuation rate: ≤ 0 0 25% Steady-state rate: 0~ 5% adjustable Ambient temperature: -40°C~+85°C Ambient humidity: < 950% Rotational speed controller shape and mounting dimensions The rotational speed controller is installed on the control box or other peripheral equipment of the motor. When installing, the air should be dryly installed and the temperature is suitable. If it is used in the place with high water and moisture density, the controller should be installed vertically. 1, 2 end connected to the actuator 3, 4 terminal connected speed sensor, speed sensor must use shielded cable, the shield part of the cable should be connected to terminal 4, but can not be connected with other parts, otherwise the interference signal may enter the speed controller; 5, 6 terminals connected to DC 24V (special order i2V) power supply, can use the diesel control battery, start battery or other stable and unregulated power supply, but to ensure the system's peak power consumption and voltage fluctuation range requirements. When using a starter battery, a charging device must be provided to ensure that the battery is fully charged. When the diesel engine is started, the short-term output voltage drop of the battery will not affect the normal operation of the governor. Speed controller positive power supply (6 feet) through the power switch (or stop switch). Fuse can be connected directly to the positive electrode of 24 V battery if necessary, that is, directly from the positive electrode of the battery. The negative power supply end (5 feet) of the rotational speed controller must be direct lead from the negative electrode of the battery. If the negative electrode of the power supply needs to be grounded, the negative electrode of the power supply is connected to the earth at the negative pole of the battery, and the earth cannot be terminated from the negative electrode (5 feet) of the controller. If the length of power line is less than 10 meters, the selection of power cord should be greater than 0.75 square millimeter; if it is more than 10 meters, the power line should be thickened correspondingly. The 7/9 terminal is connected to the potentiometer with a resistive value of 3.3K, and the genset speed range can reach 150 r/m. The 10/11 terminal is connected to the steady-state rate-adjusting switch and disconnects the steady-state rate-adjusting rate of 0. By adjusting the steady-state rate-adjusting potentiometer on the controller after closing, the steady-state adjustable rate can be set in the range of 0-5% (this switch is not provided when ordering, If the user needs to run side by side, you can use a wire to connect the 10/11 terminal short); The 7/12 terminal is connected with high/low speed switch, and when closed, it is a suffering speed and rises to high speed after disconnecting; 13 terminal connected with voltage regulator, can be directly connected to synchronous controller and load distributor to complete automatic well car and automatic load distribution function, single machine operation can not be connected. Terminal 14 external supply 10V/20mA power, but in use such as short-circuit or overload use will damage the controller. Why is Electronic Speed Regulation Diesel Generator set so popular With more and more strict control of diesel generator exhaust pollution, diesel engine fuel injection system put forward higher requirements. At present, the market is generally electronic speed-adjusted diesel generator sets. Electronic speed-adjusted diesel generator sets, its oil transport will vary with the size of the load. When the load becomes smaller, the fuel transport of the generator will also become smaller, and the fuel consumption of the diesel generator will decrease, and when the load output becomes larger, the fuel consumption of the diesel generator will also increase. In addition, the stability of the diesel generator set with electronic speed regulation is better if the automatic conversion function is added. In general, even the same power, the same model, the same configuration of diesel generator sets, but if one is electronic speed regulation and a mechanical speed governing unit prices are also very different. The difference between electronic speed regulation and mechanical speed regulation is as follows: the mechanical speed regulation of a generator set, after it is started well, the general throttle needs to be fixed, so that, regardless of the change in the load output of the generator set, the amount of oil it carries is still the same. Never change. And the electric speed-adjusted generator, its quantity of oil will vary with the size of the load. When the load becomes smaller, the oil transport of diesel generator sets will also become smaller, in which case, the fuel consumption of diesel generating units will be reduced, and when the load output becomes larger, the fuel consumption of diesel generating units will also increase. In addition, the stability of the diesel generator set with electronic speed regulation is better if the automatic conversion function is added In normal operation, the noise of diesel generator set is mainly exhaust noise. The noise of diesel generators will cause certain pollution to the environment, which will easily affect people's work efficiency and interfere with their normal life. Low noise generators/silent generators must be used in densely populated areas or in places with stringent environmental noise requirements. Therefore, it is necessary to reduce noise in the diesel generator room. 1. Ventilation and noise reduction in machine room In practical work, we must consider both the effective noise reduction and the air flow required for the operation of the generator set. Two air inlet shaft are built with bricks outside the machine room. A low-noise axial flow fan is installed under the air inlet wall to supply air to the machine room. A large air volume combined muffler is installed in the air duct to absorb airflow noise and mechanical noise. An air inlet is opened on the wall outside the air inlet duct and a protective screen is installed at the air inlet to prevent foreign matter from entering the air duct. 2. Machine room exhaust system silencing Exhaust air must be silenced through the muffler air duct provided outside the machine room to minimize noise. The outside of the muffler air duct is a brick wall structure, and the inside is a sound absorbing panel. Air outlet is arranged directly in front of the genset, and the front end of the unit radiator is provided with a vibration-damping flexible joint and a wind-conducting expansion sound-absorbing air duct, which is connected to the exhaust hot air silencing channel. Special aluminum alloy shutters and protective wire mesh are installed at the outlet of the exhaust duct to prevent foreign matter from entering the air duct. 3. Genset exhaust silencer A sound reducing enclosure can be added to the exhaust gas system of the generating set, and at the same time, the exhaust silencing pipes are all wrapped with fireproof rock wool material, which can not only reduce the heat dissipation of the unit into the machine room, but also reduce the working vibration of the unit, so as to achieve the purpose of noise attenuation. 4. The machine room sound absorption Since the generator room is brick concrete structure, it has strong noise reflection. In order to achieve the sound absorption effect, the wall and the top surface of the machine room are reasonably equipped with high-efficiency sound absorbing materials, and the sound absorbing layer structure is an aluminum alloy perforated gusset plate + centrifugal sound absorbing cotton + light steel keel + support hanger. The original average sound absorption coefficient in the equipment room is α1≈0.10. After the sound-absorbing material is installed, the average sound absorption coefficient in the machine room is α2≈0.75~0.85, and the sound absorption can reach 9~12dB(A), and the reverberation time can be reduced to 2~3s. The loudness in the equipment room is also greatly reduced, which greatly improves the working conditions and the sound insulation performance of the generator room. 5. Sound insulation system In order to ensure good sound insulation performance of the machine room, a fireproof soundproof door is installed in the connection between the machine room, and the sealing material of the door is a rubber seal strip. Other holes that cause sound leakage are blocked with brick walls. |
作者
dieselgenerator 存档
July 2022
类别 |