The compression ratio of diesel engine is the ratio of the total cylinder volume to the combustion chamber volume. The change of the compression ratio not only affects the power and economy of the diesel generator, but also affects its start-up performance. Each diesel engine is designed with an optimal compression ratio, but in use, the compression ratio is often reduced due to the influence of various related factors. The main reasons for the reduction of the compression ratio of the diesel engine and some problems that should be paid attention to in the course of maintenance are summarized as follows: I The piston is low at the end of compression 1. The matching clearance of related parts is too large. When the clearance between the crankshaft main bearing and the main journal, the connecting rod bearing and the connecting rod journal, the connecting rod bushing and the pin sear hole is too large =, during the compression process, the actual position of the piston stop point will often move down, reducing the compression ratio. Therefore, these fit gaps should be controlled within the allowable range during repair. 2. The relevant parts are deformed or the main dimensions are extremely poor. For example, when grinding the crankshaft connecting rod journal, the eccentric distance is not adjusted well, so that the rotary radius of the crankshaft after grinding becomes smaller. The bending of connecting rod shortens the enter distance between the big and small end holes of connecting rod. The often of piston pin seat hole makes the distance between the center line of piston pin seat hole and piston top plane shorter. All these factors will cause the piston to move down and the compression ratio to decrease. Therefore, the quality of repair should be guaranteed by following the operation standard. At the same time, do not forget to change the inspection, do not change or install unqualified parts. When changing parts, the contents should be checked: crankshaft radius of rotation, center distance of big connecting rod and small end hole, distance from center line of piston pin seat hole to piston top plane, distance between upper plane of body and center line of main bearing hole. II Combustor volume is larger 1. The valve and valve seat are badly worn and the valve sink is too large (or even beyond the limit). Valve and seat ring should be replaced at this time. 2. The cylinder cushion thickness exceeds the design requirement, or increases the cylinder cushion thickness artificially. The required cylinder pad shall be replaced at this time. 3. Piston top pit (part of combustion chamber) ablation defect, or the wrong parts, so that the pit volume is too large (can be checked by water injection contrast method). A qualified piston should be replaced at this point. 4. The swirl chamber on the cylinder head is burnt, or the quality is not up to standard, the volume is too large (can be checked by water injection contrast method). A qualified cylinder head should be replaced at this time. It is worth mentioning that among the factors that lead to the reduction of compression ratio, the single factor is not very important, but the effect of accumulation and superposition of multiple factors on compression ratio is great. As mentioned above, in order to control the compression ratio of diesel generator sets within a specified range, the key lies in improving the repair quality and doing the repair, measurement and selection of the parts. To the extent permitted by the technical requirements, select as small as possible assembly clearance. When the diesel engine is difficult to start, the power decreases, the fuel consumption rises, the cylinder seal, the gas distribution and the fuel supply are all normal, it seems that the reason of the failure can not be found, and the check of the compression ratio should not be ignored. Causes and treatment methods of reducing Insulation Resistance of Generator The insulation resistance of the generator decreases as follows: the insulation resistance of the generator is less than 0.5 M Ω under the thermal stability and less than 2 M Ω in the cold state. What causes the insulation resistance to decrease, and what are the corresponding treatment methods? I failure cause 1. Diesel generator set are stored in wet conditions for a long time, or in the process of transport the motor winding is dampened. 2. During maintenance, the insulation of motor winding is damaged. 3. Conductive dust in the air, such as metallurgical industrial zones, or acid / alkaline vapours, such as chemical industrial zones, enter the motor and corrode the electrical insulation. 4. Generator winding insulation natural aging. II Corresponding processing method 1. The ventilation condition of generator storage environment is improved, the damp generator is dryly treated, and the three-phase outlet of generator stator winding is connected directly and fastly. The voltage regulator in the excitation circuit is adjusted to the position of the maximum resistance, the generator is started, the speed is accelerated to the rated speed, and the excitation current is adjusted. The stator winding short circuit current shall not exceed the rated current. The drying time depends on the short circuit current and the damp condition of the generator. 2. Replace the insulation damaged winding or tank. 3. Improve the environment of the generator or transfer the installation of the generator. 4. Overhaul the generator, replace the winding and insulating material or replace the new generator.
0 评论
When we purchase and select diesel generator sets, they often confuse the relationship and definition between apparent power, active power, rated power, maximum power and economic power. For this reason, we have sorted out the relationship between them so that everyone can understanding. 1. The unit of apparent power is KVA, which is used to express the capacity of transformers and UPS. 2. The active power is 0.8 times the apparent power, and the unit is KW. It is used to power generation equipment and electrical equipment in China. 3. The rated power of a diesel generator set is the power that can be continuously operated for 12 hours. 4. The maximum power is 1.1 times the rated power, but only 1 hour is allowed within 12 hours. 5. The economic power is 0.75 times of the rated power, which is the output power of the diesel generator set that can be operated for a long time without time limit. When this power is running, the fuel is the most economical and the failure rate is the lowest. When selecting a diesel generator set, you can measure the amount of load you need beforehand, and then purchase the generator set according to the load. 1. First of all, it is necessary to distinguish the difference between the apparent power and the effective power of the diesel generator set. The relationship between them is 1KVA=0.8KW. The imported genset generally uses KVA to represent the power generation, while the domestic power equipment is generally represented by KW, so when calculating the power, the KVA should be converted into KW by 20%. 2. Secondly, it is necessary to determine the rated power and maximum power of the diesel generator set to be selected. 3. In addition, determining the power of the generator set does not simply add up the power of all the appliances, but also needs to consider the starting mode of the appliance. The general starting mode is divided into direct starting and step-down starting or variable frequency starting. The former starting current is about 6 times of working current, the instantaneous power will reach 6 times of rated power. The latter starting current is about 3 times, and the instantaneous power is also power 3 times. Therefore, when selecting the power of the generator set, in addition to considering the sum of the power of all the appliances, it is also necessary to consider the starting power of each appliance. Why Size of Diesel Generator Should I Purchase? Under normal circumstances, the diesel engine matched with the generator users 12h power or continuous power as the calibration power. When the 12h power is used to indicate the calibration power, it indicates that the diesel engine has a continuous running time of 12h under standard power (standard environmental conditions), including continuous operation for 1h under more than 10% of the rated power, when continuous power is selected as the calibration power, it means the diesel engine allows for long-term continuous operation, including up to 10% of rated power for 1h. Typically the continuous power is 90% of the 12h power. The calibration power indicated on the nameplate of the diesel engine is determined according to the specified standard environment. When the environmental conditions and the standard regulations are different, the power shall be corrected according to the above method. When supporting, the diesel engine should have sufficient power to ensure that the generator outputs the rated power under the condition of calibration operation. According to experience, the ratio of diesel engine power to generator power is 1.35:1 for plain fixed generators and 1.6 for mobile generators. Table 1 below shows the matching characteristics of various diesel generator sets. After purchasing the diesel generator set, users should pat attention to safety when using it. Especially when the generator set is just stopped, do not unscrew the radiator cover to fill or replace the coolant. Otherwise, the high temperature cooling water will cause serious burns. The genset is shut down and the diesel engine is completely cooled. The operation and precautions of the diesel generator set after shutdown are explained in detail below. 1. Shutdown operation of diesel generator sets Receive a signal to ready to disassemble and perform a deceleration unloading. After unpacking, the machine gradually slowdown and cool down, and listen to the machine for any noise and determine its location and cause to stop. 2. The fuel pump is turned off normally (in special causes, faulty or emergency stop can be used), and the external circulation pump is turned off. 3. Brakes must be carried out when parking for more than 1 hour. 4. After parking, perform genset maintenance according to the operation, keep the equipment in good condition and clean. 5. Conduct a comprehensive inspection of each operating part of the diesel engine at least once a week, and find that the problem should be dealt with in a timely manner. Precautions for diesel generator set shutdown 1. On-duty personnel must stick to their posts, do their jobs, and be diligent and strictly abide by the operating procedures. 2. The duty officer should carefully fill in the shift record. For the problems in the operation of the genset, it is necessary to deal with the shift, and make a written explanation of the next shift in detail, and report the key issues to the leader in a timely manner. 3. After the tools used are used up, you need to check the positioning and find out where to go for lost tools and parts. 4, smoking is prohibited in the main room, the workplace is kept hygienic, and measures are taken to eliminate noise. Short-term shutdown maintenance method for diesel generator sets If the diesel generator set needs to be deactivated for a period of time (1 to 3 month), it is necessary to do the cleaning work and the necessary oil seal measures to prevent rust. I Before storage 1. Clean the surface of the diesel generator set, check for no visible dirt, oil, rust water, etc., then blow dry with compressed air, use a brush to evenly apply the anti-rust oil to the machines surface of all diesel generator metal surfaces (That is, the unfinished machined surface), note that the surface of rubber parts, plastic parts and fabric parts is not allowed to be coated with anti-rust oil. Note:The surface of the accessory drive pulley must be protected against rust. II during storage Charge the battery every month. Check the battery level, add as needed, and then charge. Use the turning tool to move the crankshaft 3-4 times a month. III Used after unpacking When enabled, remove the fuel injection pump, send it to the designated service station for adjustment. Remove the cover and the wrapping, install the fuel injection pump to pump the fuel to the fuel system. Connect the battery cable and tension the drive belt, check the level of lubricant and coolant, add a proper amount of cleaning oil to the booster inlet. Use the turning tool to turn the crankshaft 3-5 turns first. Then start the diesel generator set in the corect way. How to properly maintain the diesel generator set for long term shutdown? If the diesel generator set is deactivated for more than 3 months, it needs to be sealed. The precautions are as follows: 1. After the last diesel generator set is used, the diesel generator oil is exhausted in the hot state, including the oil in the oil filter. Since the coolant has an anti-rust function, it does not need to be discharged. Add the qualified storage oil of the specified capacity to the crankcase, start the diesel generaotr st to idle speed, stop the operation for 1-1.5 minutes, and then release the sealing oil from the oil pan. The engine internal seal oil is dehydrated CF grade 15W/40 lubricant. 2. The external surface of the diesel generator set is cleaned against rust and other storage. Refer to the diesel generator set short-term outage maintenance method before the storage, 1, 2, 3, 4, 5, and the diesel generator set is affixed with a label on the label. The diesel engine of the diesel generator set has no oil and should not be used. I During storage Charge the battery every month. Check the battery level, add as needed, and then charge. Use the turning tool to move the crankshaft 3-4 times a month. II Used after unpacking Remove the diesel generator cover and remove the sealing material of each nozzle, when it is activated, remove the fuel injection pump and send it to the designed service station for adjustment, install the fuel injection pump to pump the fuel to the fuel system. Connect the battery continuously, tension the drive belt, then add the oil and add the right amount of cleaning oil to the booster inlet. Then start the diesel generator set in the correct way. If it is more than 2 years old, the coolant must be replaced and the cooling system cleaned. The engine of the diesel generator set drives the generator to convert the energy of the diesel into electrical energy. The generator set uses the principle of 'electromagnetic induction', and the generator outputs an induced electromotive force, which can generate current through a closed load circuit. In addition, a range of diesel and generator controls, protection devices and circuits are required to achieve a usable, stable power output. The following describes the working principle of the formation of the internal magnetic field of the diesel generator set. Generators are divided into two major categories: DC generators and alternators. The latter can be divided into synchronous generators and asynchronous generators. Synchronous generators are most commonly used in modern power stations. This type of generator is characterized by DC current excitation, which can provide reactive power to meet the needs of various loads. Because there is no independent excitation winding, the asynchronous generator has a simple structure and convenient operation, but can not provide reactive power to the load, and also needs to draw the lag magnetization current from the connected power grid. Therefore, the asynchronous generator must be operated in parallel with other synchronous units or with a considerable number of capacitors. This limits the range of applications of asynchronous generators and can only be applied to small automated hydropower plants. DC power supplies used in urban trams, electrolysis, and electrochemistry industries used DC generators before the 1950s. However, DC generators have commutators, which are complicated in structure, time-consuming to manufacture, expensive, easy to malfunction, difficult to maintain, and inefficient as an alternator. Therefore, since the advent of high-power controllable rectifiers, there has been a trend to use AC power to obtain DC power through semiconductor rectification to replace DC generators. Synchronous generators are classified into three types: turbo generators, hydroelectric generators and diesel generators according to the different prime movers used. What they have in common is that in addition to the small motor that uses a permanent magnet to generate a magnetic field, the general magnetic field is generated by a direct current excitation coil, and the excitation coil is placed on the rotor, and the armature winding is placed on the stator. Because the voltage of the excitation coil is lower, the power is smaller, and there are only two outlet heads, which are easily led out through the slip ring; the armature winding has a higher voltage and a large power, and the three-phase winding is used, and there are three or four lead-out heads. It is convenient to put on the stator. The armature (stator) core of the generator is laminated with silicon steel sheets to reduce iron loss. The rotor core can be made of a monolithic steel block because the magnetic flux passed through does not change. In large motors, because the rotor is subjected to strong centrifugal force, the material used to make the rotor must be made of high quality steel. What are the adverse effects of generator loss of magnetic field? When the generator loses magnetism, the rotor loses the excitation current. The generator after demagnetization will generate differential current in the damper winding, rotor surface and rotor winding of the rotor, causing additional temperature rise, which may cause local high temperature of the rotor, which may easily cause some defects. The impact is summarized as follows: 1. After the generator loses excitation, the reactive power is changed to absorb reactive power, and the larger the slip, the smaller the equivalent reactance of the generator, and the greater the reactive power absorbed, causing the stator winding of the loss-generating generator to pass current. 2. After the rotating speed of the rotor and the rotational speed of the rotating magnetic field synthesized by the startor winding are deviated, the rotor surface (including the body, the wedge, the guard ring, etc.) will induce the slip frequency current, causing local overheating of the rotor, which is the most harmful to the generator. 3. During asynchronous operation, the torque changes periodically, so that the stator, rotor and its foundation are constantly subjected to abnormal mechanical moments, and the vibration of the unit is intensified, threatening the safe operation of the generator. 4. When the demagnetization is moderately serious, if the protection is not acted in time, the generator and the turbine rotor will be overspeeded immediately, and the consequences are unimaginable. 5. When a generator is demagnetized, due to the voltage drop, other generators in the power system will increase their reactive output under the action of the automatic adjustment of the excitation device, thereby causing overcurrent of some generators, transformers or lines. The backup protection may be mistaken due to overcurrent, which will widen the scope of the accident. 6. Low-excitation and de-energized generators absorb reactive power from the system, causing the voltage of the power system to decrease. If the reactive power reserve in the power system is insufficient, the voltage in some adjacent points in the power system will be lower than the allowable value. It destroys the stable operation between the load and each power supply, and even collapses the power system voltage. 7. After a generator is demagnetized, due to the swing of the active power of the generator and the drop of the system voltage, it may cause the step-out between the adjacent normal operation generator and the system, or between the parts of the power system, so that the system Oscillation occurred. 8. The larger the rated capacity of the generator, the greater the reactive power shortage caused by low excitation and demagnetization, and the smaller the capacity of the power system, the smaller the ability to compensate for this reactive power shortage. Therefore, the greater the ratio of the unit capacity of the generator to the total capacity of the power system, the more serious the adverse effect on the power system. It can be seen that the loss of magnetism of the generator is likely to have more serious consequences, which will not only damage the generator itself, but also affect the power system. For safety reasons, the generator management personnel must ensure the inspection of the excitation circuit, find problems in time, and avoid the occurrence of generator loss of magnetic failure. How Does a Diesel Generator Set Form a Magnetic Field The engine of the diesel generator set drives the generator to convert the energy of the diesel into electrical energy. The generator set uses the principle of 'electromagnetic induction', and the generator outputs an induced electromotive force, which can generate current through a closed load circuit. In addition, a range of diesel and generator controls, protection devices and circuits are required to achieve a usable, stable power output. The following describes the working principle of the formation of the internal magnetic field of the diesel generator set. Generators are divided into two major categories: DC generators and alternators. The latter can be divided into synchronous generators and asynchronous generators. Synchronous generators are most commonly used in modern power stations. This type of generator is characterized by DC current excitation, which can provide reactive power to meet the needs of various loads. Because there is no independent excitation winding, the asynchronous generator has a simple structure and convenient operation, but can not provide reactive power to the load, and also needs to draw the lag magnetization current from the connected power grid. Therefore, the asynchronous generator must be operated in parallel with other synchronous units or with a considerable number of capacitors. This limits the range of applications of asynchronous generators and can only be applied to small automated hydropower plants. DC power supplies used in urban trams, electrolysis, and electrochemistry industries used DC generators before the 1950s. However, DC generators have commutators, which are complicated in structure, time-consuming to manufacture, expensive, easy to malfunction, difficult to maintain, and inefficient as an alternator. Therefore, since the advent of high-power controllable rectifiers, there has been a trend to use AC power to obtain DC power through semiconductor rectification to replace DC generators. Synchronous generators are classified into three types: turbo generators, hydroelectric generators and diesel generators according to the different prime movers used. What they have in common is that in addition to the small motor that uses a permanent magnet to generate a magnetic field, the general magnetic field is generated by a direct current excitation coil, and the excitation coil is placed on the rotor, and the armature winding is placed on the stator. Because the voltage of the excitation coil is lower, the power is smaller, and there are only two outlet heads, which are easily led out through the slip ring; the armature winding has a higher voltage and a large power, and the three-phase winding is used, and there are three or four lead-out heads. It is convenient to put on the stator. The armature (stator) core of the generator is laminated with silicon steel sheets to reduce iron loss. The rotor core can be made of a monolithic steel block because the magnetic flux passed through does not change. In large motors, because the rotor is subjected to strong centrifugal force, the material used to make the rotor must be made of high quality steel. What are the adverse effects of generator loss of magnetic field? When the generator loses magnetism, the rotor loses the excitation current. The generator after demagnetization will generate differential current in the damper winding, rotor surface and rotor winding of the rotor, causing additional temperature rise, which may cause local high temperature of the rotor, which may easily cause some defects. The impact is summarized as follows: 1. After the generator loses excitation, the reactive power is changed to absorb reactive power, and the larger the slip, the smaller the equivalent reactance of the generator, and the greater the reactive power absorbed, causing the stator winding of the loss-generating generator to pass current. 2. After the rotating speed of the rotor and the rotational speed of the rotating magnetic field synthesized by the startor winding are deviated, the rotor surface (including the body, the wedge, the guard ring, etc.) will induce the slip frequency current, causing local overheating of the rotor, which is the most harmful to the generator. 3. During asynchronous operation, the torque changes periodically, so that the stator, rotor and its foundation are constantly subjected to abnormal mechanical moments, and the vibration of the unit is intensified, threatening the safe operation of the generator. 4. When the demagnetization is moderately serious, if the protection is not acted in time, the generator and the turbine rotor will be overspeeded immediately, and the consequences are unimaginable. 5. When a generator is demagnetized, due to the voltage drop, other generators in the power system will increase their reactive output under the action of the automatic adjustment of the excitation device, thereby causing overcurrent of some generators, transformers or lines. The backup protection may be mistaken due to overcurrent, which will widen the scope of the accident. 6. Low-excitation and de-energized generators absorb reactive power from the system, causing the voltage of the power system to decrease. If the reactive power reserve in the power system is insufficient, the voltage in some adjacent points in the power system will be lower than the allowable value. It destroys the stable operation between the load and each power supply, and even collapses the power system voltage. 7. After a generator is demagnetized, due to the swing of the active power of the generator and the drop of the system voltage, it may cause the step-out between the adjacent normal operation generator and the system, or between the parts of the power system, so that the system Oscillation occurred. 8. The larger the rated capacity of the generator, the greater the reactive power shortage caused by low excitation and demagnetization, and the smaller the capacity of the power system, the smaller the ability to compensate for this reactive power shortage. Therefore, the greater the ratio of the unit capacity of the generator to the total capacity of the power system, the more serious the adverse effect on the power system. It can be seen that the loss of magnetism of the generator is likely to have more serious consequences, which will not only damage the generator itself, but also affect the power system. For safety reasons, the generator management personnel must ensure the inspection of the excitation circuit, find problems in time, and avoid the occurrence of generator loss of magnetic failure. When the diesel engine is working, the water level in the radiator will gradually decrease due to the evaporation of the water. Therefore, the water level in the radiator should be checked before starting and when the starting time is long. If it is lower than the drain pipe, Replenish clean soft water. If it is hard water, it should be softened first. When the diesel engine is used under the environmental conditions below 0 °C, the cooling water should be prevented from freezing to avoid being freezing and cracking of the parts. Therefore, the cooling water should be drained whenever the diesel engine is finished running. For models with closed-loop cooling system, anti-freeze coolant with appropriate freezing point can be used according to the local minimum ambient temperature. Commonly used coolants include ethylene glycol plus water and alcohol, and glycerin plus water. The corresponding formula is shown in the table below for your reference. When using flammable antifreeze coolant, it is flammable due to ethylene glycol, alcohol and glycerin. Before using the antifreeze coolant, the diesel engine should clean the dirt in the cooling system to avoid new chemical deposits and affect the cooling effect. For diesel engines that use antifreeze coolant, it is not necessary to release the coolant after each stop, but it is necessary to periodically replenish and check the composition. Never use 100% antifreeze as a coolant. If there is too much scale and dirt in the diesel engine cooling system, it can be cleaned with a cleaning solution. The cleaning solution can be prepared from water, soda (Na2CO3) and water glass (Na2SiO3) by adding 40 g of soda and 10 g of water glass per liter of water. When cleaning, the cleaning liquid is poured into the cooling water chamber of the diesel engine, and the running water reaches the outlet water temperature greater than 60 ° C, and the operation continues for about 2 hours to stop, and then the cleaning liquid is discharged. After the diesel engine is cooled, rinse it twice with clean fresh water, drain it and then pour it into the cooling water to start the operation, so that the outlet water temperature reaches 75 °C or more, stop the sewage, and finally fill in the new cooling water. How to use the diesel cooling water test kit For diesel engine cooling water, you must choose soft water instead of hard water. 40% antifreeze and 3~5% rust inhibitor (DCA4) can be added to the cooling water. The concentration of the additive must be checked every 500 hours to keep it within the correct range. How to use the cooling water test kit 1. When the temperature of the cooling water in the diesel engine is (10-55) °C, unscrew the blockage to discharge the cooling water and fill the semi-plastic cup. 2. Dip the test paper into the collected water sample, stir the water sample, and after 3 to 5 seconds, remove the test paper and shake off the water drops on the paper. 3. Wait 45 seconds until the color of the test strip changes. 4. The test paper of the changed color is compared with the color list label on the storage bottle to calculate the value. 5. The color tone that has become yellowish green is compared with the green indication of the test paper storage bottle to determine the concentration. (The concentration display must be between 33% and 50% in the tonal range). 6. The brown color in the middle of the test strip and the pink color in the lower position represent the concentration of the rust preventive. The appropriate range is to satisfy the values of brown (vertical) and pink (horizontal), and is located in the range of 0.3 to 0.8 in the color list label on the test paper storage bottle. . 7. If it is lower than 0.3, a rust inhibitor (DCA4) should be added; if it is higher than 0.8, 50% of the cooling water should be poured out and fresh cooling water should be refilled. Then adjust to the appropriate concentration. The coolant must generally be replaced every 6 months, otherwise lime and corrosive deposits will occur, affecting the diesel engine cooling system. How to soften hard water into cooling water suitable for diesel generator sets The cooling water used in the diesel generator set should be clean soft water. Soft water refers to water with little minerals, such as rain and snow. Most of the water is commonly used in river water, well water, etc. Before it is softened, it contains a lot of minerals in addition to sediment and other impurities. This water is usually hard water. After the salt water is heated in the cylinder, the mineral will form scale on the water jacket wall. The heat transfer capacity of scale is very poor, its thermal conductivity is 50 times lower than that of brass, and 20 to 30 times lower than that of cast iron. Therefore, the heat of the cylinder and the cylinder head cannot be smoothly transmitted to the cooling water, which easily causes the machine to overheat, even burns the lubricating oil, accelerates the wear of the components such as the cylinder and the piston connecting rod group, thereby reducing the power of the diesel engine. In addition, too much scale can not block the water pipe and the cylinder water channel, making the cooling water circulation difficult. With the increase of temperature in summer, the demand for electricity will also increase, so more diesel generators will be used, so what should we pay attention to in the process of using diesel generators in summer? The following is a detailed introduction of the six points for attention when diesel generator sets are used in summer. 1. Good ventilation to avoid high temperature. The installation place should be well ventilated, the generator end should have enough air inlet, and the diesel engine end should have good air outlet. The air outlet area should be more than 1.5 times larger than the water tank area. Reminder: diesel generator SET should not run in the sun exposure to high temperature environment, in case the generator block heating too quickly lead to failure. 2. Keep clean Keep the installation area clean and avoid the presence of corrosive gases and vapors, such as acidic, alkaline, etc. It is best to install fire extinguishing devices. 3. Exhaust smoke unobstructed In indoor application, the exhaust pipe must be led outside, the diameter of the pipe must be ≥ the diameter of the exhaust pipe of the silencer, the elbow of the connected pipe should not exceed 3, in order to ensure the smoke discharge is smooth, and the pipe should be inclined down 5-10 degrees to avoid Rain Water injection; If the exhaust pipe is installed vertically up, a rain shield must be installed. 4. Shockproof When the foundation adopts concrete, the horizontal degree of the unit must be measured with the horizontal ruler during installation, so that the unit is fixed on the horizontal foundation. Between the unit and the foundation shall be a special shock cushion or bolts with bottom foot. 5. protective ground connection The generator unit shell must have reliable protective grounding. For the generator which must have neutral point direct grounding, it must be neutral ground by professional personnel, and be equipped with lightning protection device, it is strictly forbidden to use the electric power earthing device to conduct neutral point direct grounding. 6. bilateral switch The two-way switch between generator and power must be very reliable to prevent power from being sent backwards. The connection reliability of the two-way switch needs to be verified by the local power supply department. Local power supply department inspection approval. Since the diesel generator set itself produces high temperature when it is in operation, with the increasing of the external temperature in summer, how to prevent the safe use of diesel generator set in the high temperature weather is often concerned by many users. Below by starlight small to introduce the diesel generator summer maintenance method. 1. Ensure sufficient circulating cooling water First of all, the circulating cooling water in the diesel generator tank should be kept in sufficient condition so that the maximum heat dissipation can be achieved during the operation of the diesel generator. 2. Keep the coolant in place When the engine is in a cold state, the coolant level shall be added in time if the liquid level is lower than the minimum mark of the expansion tank between the top and lowest marks of the expansion tank. Note that the coolant in the expansion tank cannot be filled and should leave room for expansion. 3. Correct use of closed cooling system When the engine is working, the coolant vapor enters the expansion tank and then flows back to the radiator after cooling, which can prevent a large amount of evaporation loss of the coolant and raise the boiling point temperature of the coolant. The cooling system should use high quality coolant with anti-corrosion, anti-boiling, anti-freezing and anti-scale, and must be sealed in order to achieve results. 4. Maintain external and internal cleanliness of the cooling system The radiator of generator set has soil on the outside, oil stain or heat sink will affect the passage of wind when it is deformed due to impact, and the radiator becomes worse, which results in the excessive temperature of the coolant. So the radiator should be cleaned or trimmed in time. Additionally, the heat transfer of the cooling fluid will be affected by the fouling in the cooling system, when the fouling is accumulated in the sand or oil. The fouling in the cooling system will increase if the poor quality coolant or water is added, and the heat transfer capacity of the fouling is only one-tenth of that of the metal, thus the cooling effect will be worse. 5. Operator standard operation Because the temperature is high and the operation staff of the diesel generator set are relatively few, at this time, when operating the diesel generator set in the generator room, we must pay attention to safety in order to prevent the water in the water tank of the diesel generator set from opening the pot because of the high temperature. It is possible that water will splatter and hurt people everywhere. As the temperature rises slowly, the heat dissipation and noise reduction of diesel generator sets become the focus of attention. What are the precautions for reducing noise and heat dissipation in diesel generator room?
First of all, in the design of emergency diesel generator room noise reduction, we should consider the ventilation of the engine room. The volume of ventilation is calculated on the basis of the amount of air needed for engine combustion and the amount of air exchange required for the heat dissipation of the generator set. The sum of gas and air exchange is the ventilation of the engine room. This is a change value, which is the temperature rise of random rooms. When considering the noise reduction in the computer room, the ventilation rate of the computer room should be strictly according to the standard, that is, the temperature rise of the engine room should be controlled within 5 ℃, and the ventilation required by the unit is the largest. Secondly, in order to calculate the cross section of the inlet and outlet air outlet according to the ventilation volume and the minimum air velocity of the exhaust muffler in the engine room. The air inlet and outlet designed accordingly can meet the heat dissipation requirements of the engine room in general. Of course, this is a higher standard and a higher cost. It needs a professional noise reduction manufacturer to design and construct, which can satisfy the ideal noise reduction effect and sufficient heat dissipation condition at the same time. Thirdly, the noise reduction and heat dissipation of the diesel generator room is also related to the requirements of the user. According to the change of environmental temperature, users can have different emphasis on noise reduction and heat dissipation. For example, in winter, you can properly pursue the effect of noise reduction. In the hot summer, in order to meet the full heat-dissipation of the computer room, in the area of noise reduction made some concessions. Especially in the hot summer, the key is to ensure good ventilation and heat dissipation in the computer room. Users can start now to prepare for a quiet, safe operating environment for diesel generators. Ensure the best effect of the unit, but also for the safety of the operation to add a guarantee. Matters needing attention in the use of diesel-generating units radiators. The radiator of the diesel generator unit is one of the indispensable parts in the configuration of the diesel generator unit, because it takes on a large amount of heat generated by the diesel generator set when it is loaded and ensures the continuous work of the genset. Below are four details to be paid attention to in the operation of radiator of generator set 1. The coolant of the radiator in operation is usually very hot and pressurized. Do not clean the radiator or remove the pipe without cooling. Do not work on the radiator or open the fan cover while the fan is rotating. 2. Prevent corrosion. Always keep pipe joints free of leakage, and regularly add water to the top of the radiator to drain air to keep the system "airless". Radiators should not be partially injected with water as this accelerates corrosion. For non-working generators, water should be fully emptied or filled. If possible, use distilled water or natural soft water and add appropriate antirust agent. 3. External cleaning. In the dust-rich or fouling environment, the gap in the radiator may be blocked by debris, insects and other substances, thus affecting the efficiency of the radiator. Regular cleaning of these light deposits can be done with low-pressure hot water and cleaner spray, ejecting steam or water from the front of the radiator to the fan. If the jet from the opposite direction will only blow the dirt into the center. When using this method, use cloth to block diesel engines and alternators. Stubborn deposits, which cannot be removed by this method, can be removed from the radiator and soaked in hot alkaline water for about 20 minutes, then rinsed with hot water. 4. Internal cleaning. If the connection leaks, you have no choice but to use hard water for some time. Or because electricity has been running for some time and no rust remover, the system may be clogged by scale. Scale removal may follow the following steps: A. Drain the water from the heat dissipation system, and then remove the pipe from the place where the diesel engine is connected. B. Accurate 4% acid solution and clear water, the acid into the water, do not reverse the process. C. Wait a few minutes to mix, and then heat the solution to 49 ℃ (120), which is the highest point and can't be higher. D. Slowly pour the solution through the filter cap or a dissection into the pipe, which will bubble. When the chemical reaction stops, fill the radiator with the hot solution. E. Let the solution stay in the system for a few minutes, then put the solution back into the original container from the bottom pipe or drain. F. Check the inside of the tank, if there is still scale, repeat the above steps to enhance the acid solution to 8. G. After scale removal, neutralize the acid reaction by following the following steps: Fill the container with clear water, heat to boiling point, add daily soda crystals, and add 20 liters of water (1 pound for 4 gallons of water) to 20 liters of water (1 pound for 4 gallons of water) in proportion as follows. Fill the radiator with this solution and let it flow back to the original container. H. The radiator is flushed several times with the method mentioned above. Finally, the radiator is stopped in the radiator for at least one hour after filling, and the radiator is flushed with hot water after emptying. I. Before reinstalling and using the radiator, use water twice the normal working pressure to test for leakage, sometimes due to the removal of scale and leakage. J. Before rerunning, the coolant is added with the necessary anticorrosive agent and a proper amount of condensing agent. Diesel generator sets will produce a lot of heat during operation, if the heat can not be removed in time, it will lead to the damage of diesel engine. Therefore, good heat dissipation must be maintained. In order to ensure the good heat dissipation effect of the generator set, it is necessary to ensure the good ventilation effect in the generator room and to maintain the normal operation of the radiator of the diesel generator set. Matters needing attention in radiator ventilation of diesel generator sets. 1. The inlet baffle and shutter should be able to adjust the gas flow rate when in operation (E. G. the narrow blade shutter assembly is more resistant than the wide leaf window assembly). 2. Radiators must use flexible pipe joints to absorb displacement and vibration of diesel generators to prevent noise from spreading. 3. In order to reduce fan noise and reduce the adverse effects of external wind, the baffle should be increased in the vicinity of ventilation inlet and outlet. 4. The automatic switch should close the air inlet and outlet when the diesel generator set is stopped under the high and cold climate. The thermostatic control valve should be partially opened for partial air circulation during operation of diesel generator units to reduce the intake of cold air. When diesel generator sets start up, the inlet and outlet valves should be all opened, and the circulation control valves should be closed when the temperature is above 60 °F (16 ℃). 5. Except in the cold climate, the ventilation air should be discharged directly from the room. It is forbidden to be used to heat other rooms (except the generator room). |
作者
dieselgenerator 存档
July 2022
类别 |