Any spare parts of engine is important for a diesel generator set. In this article, you will learn the maintenance procedures of Perkins 4000 Series diesel genset. The post mainly introduces the genset belt, fan bearings and crankcase breather related technical knowledge. FAN BEARINGS AND BELTS WARNING!! Disconnect batteries or any other means of starting. Remove the mesh guard around the fan belts, grease the fan and jockey pulley bearings Fig.23 using high melting point lithium based grease (e.g. Shell Alvania R.A.) Check the tension and condition of the fan belts. Using a spring balance and rule, or a belt tension indicator, check that the force compares with the kgf (lbf) values shown below for the correct belt deflection. See Fig.23. Fan belts if worn, should be replaced as a complete, matching set. Individual belts should NOT be replaced. To adjust slacken the jockey pulley pivot and adjuster bolts, and operate the jockey pulley lever. Moving the jockey pulley lever outwards will tension the belts and inwards will slacken the belts. The correct tension is obtained by measuring the deflection at the mid point between the fan pulley and the crankshaft pulley when the above force is applied. To apply the force place a rule across the outside width of the belts and attach spring balance as shown Fig.23 pull on the spring balance until the required force is reached and measure the belt deflection. Adjust the position of the jockey pulley lever until the force on the spring balance and the belt deflection agree with the figures given above. When using a belt tension indicator position the indicator on top of a belt at the mid center distance and apply a force at right angles to the belt deflecting it to the point where the lower marker is level with the top of the adjacent belt. Read off the force value indicated by the top edge of the upper marker. Having set the tension on the belts, tighten the adjuster and pivot bolts. refit the fan belt guard. NOTE: If the measured force falls within the values given,the drive should be satisfactory, if it is below the lower value under tensioning is indicated. A new drive should be tensioned to the higher value to allow for the normal drop in tension during the running-in period. After the drive has been running for 30 minutes, the tension should be checked and re-adjusted to the higher value. FAULT TRACING a) Small cracks on V-Belt Side and Base Generally caused by lack of belt tension but excessive heat and/or chemical fumes can also lead to similar failure. b) V-Belt swelling and softening Caused by excessive contamination by oil, certain cutting fluids or rubber solvents. c) Whipping during running Usually caused by incorrect tensioning principally on long center drives. If slightly higher (or lower) tension does not cure the problem there may be a critical vibration frequency in the system which requires re-design or a banded belt (2 belts banded together to make a W belt). CRANKCASE BREATHING WARNING!! Disconnect batteries or any other means of starting. When using compressed air or cleaning agents always wear eye protection, and protective gloves. CRANKCASE BREATHER ON EARLIER ENGINES (RADIATOR COOLED) The crankcase breather is mounted on the side of the radiator Fig.24 and is connected to an elbow mounted on the gearcase by a flexible pipe Fig.26. CRANKCASE BREATHER ON EARLIER ENGINES (HEAT EXCHANGER COOLED) The crankcase breather is mounted on the side of the thermostat housing Fig. 25 and is connected to a breather body mounted on the gearcase by a flexible extension pipe Fig.26. Unscrew the breather by turning it anti-clockwise, wash thoroughly using a suitable cleaning agent, shake as dry as possible, finally blow dry with compressed air then screw the breather firmly back into position. Key (Fig.26) 1. Position of breather when engine is fitted with a radiator 2. Position of breather when engine is fitted with heat exchanger 3. Flexible pipe
To clean the breather remove the top cover and withdraw the two wire mesh elements and wash thoroughly using a suitable cleaning agent, Shake as dry as possible, finally blow dry with an compressed air. Refit the elements into the breather body, and fit the top cover firmly. NOTE: When replacing the cover check the sealing gasket of diesel generator is in good condition and the cover has located on its dowel.
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This post is mainly written to introduce how to adjust crosshead, injector and valves of Cummins NT diesel engines correctly. Pay attention to reading and you will learn more. Crosshead Adjustment Note: Crosshead adjustment should always be made before attempting to adjust the valves. 1. Loosen the locknut on the crosshead adjusting screw. Turn the adjusting screw out at least one turn. 2. Hold the crosshead down against its mating valve stem. Turn the adjusting screw back in until it touches the valve stem. Hold the adjusting screw in this position and tighten the locknut. 3. Tighten the adjusting screw locknut to 25 to 30 ft-lb [34 to 41 N*m] torque. Note: When ST-669 Torque Wrench Adapter is used, tighten the locknut to 22 to 26 ft-lb [30 to 35 N*m] torque. 4. Check the clearance between the crosshead and valve spring retainer 1 and 2. Fig. 2-19 with a wire gauge. Tighten must be a minimum of 0.025 inch [0.64 mm] clearance. Valve Adjustment The “VS” markets used when adjusting the injectors is also used when adjusting the valves; however, the valves to be adjusted are not on the same cylinder as the injector. See Table 2-3 for the correct valves to adjust. Example: When 1-6 “VS” is used, the injector on cylinder number 3 is adjusted and the valves on cylinder number 5 are adjusted. 1. Loosen both locknuts on the intake and exhaust valve adjusting screws. 2. Insert the proper feeler gauge between the rocker lever and crosshead contact surfaces. (Fig.2-20). See Table 2-9 for valve clearance valves. 3. Turn the adjusting screw down until the rocker lever just touches the feeler gauge. Hold the adjusting screw in this position and tighten the locknut to 40 to 45 ft-lb [54 to 61 N*m] torque. Note: When ST-669 Torque Wrench Adapter is used, tighten the locknut to 35 to 40 ft-lb [47 to 54 N*m] torque. 4. Always adjust the valves after the injector adjustment. Move to the next cylinder as indicated in Table 2-3 and repeat the adjustments until all injectors and valves have been set. Adjust Injector and Valves (Torque Method For Top-Stop Injector Engines) Timing Mark Alignment 1. Loosen the injector rocker lever adjusting nut on all cylinders. This will aid in distinguishing between cylinders adjusted and not adjusted. 2. Bar the engine in the direction of rotation until a valve set mark aligns with the mark or pointer on the gear case cover. 3. Check the valve rocker levers on the two cylinders aligned as indicated on the pulley. On one cylinder of the pair, both rocker levers will be free and the valves closed; this is the cylinder to be adjusted. 4. Adjust the injector plunger first, then the crossheads and valves to the clearances indicated in the following paragraphs. 5. For the firing order see Table 2-5 for Inline Engines. Table 2-5: Engine Order N-855 Engines Right Hand Rotation Left Hand Rotation 1-5-3-6-2-4 1-4-2-6-3-5 6. Continue to bar the engine to the next “VS” mark and adjust each cylinder in the firing order. Note: Only one cylinder is aligned at each mark. Two complete revolutions of the crankshaft are required to adjust all cylinders. Injector Plunger Adjustment The injector plungers must be adjusted with an inch-pound torque wrench to a definite torque setting. A torque wrench with a screwdriver adapter can be used for this adjustment. Turn the crankshaft in the direction of rotation until one of the “VS” marks are aligned with the pointer. Check both of the cylinders indicated on the pulley to see which valve rocker levers, this is the cylinder to be adjusted. 1. Turn the adjusting screw down until the plunger contacts the cup and advance an additional 15 degrees to squeeze the oil from the cup. 2. Loosen the adjusting screw one turn; then using an inch torque wrench with screwdriver adapter tighten the adjusting screw to the valve shown in Table 2-6 and tighten the locknut to 40 to 45 ft-lbs [54 to 61 N*m] torque. If ST-669 Torque Wrench Adapter is used, torque to 30 to 35 ft-lbs [41 to 47 N*m]. Crosshead Adjustment Crossheads are used to operate two valves with one rocker lever. The crosshead adjustment is provided to assure equal operation of each pair of valves and prevent strain from misalignment. Table 2-6: Injector Plunger Adjustment – Inch-lbs [N*m] Cold Set Hot Set Aluminum Rocker Housing 72 [8.1] 72 [8.1] Valve Adjustment The same engine position used in adjusting the injectors is used for settings the intake and exhaust valves. Adjust the injectors and the valves on the same cylinder at the same time. 1. While adjusting the valves, make sure that the compression release, on those engines so equipped, is in the running position. 2. Loosen the locknut and back off the adjusting screw. Insert a feeler gauge between the rocker lever and crosshead. Turn the screw down until the lever just touches the gauge and lock the adjusting screw in this position with the locknut. Tighten the locknut to 40 to 45 ft-lbs [54 to 61 N*m] torque. When using ST-669 torque to 30 to 35 ft-lbs [41 to 47 N*m]. 3. Always make final valve adjustment at stabilized engine lubricating oil temperature. See Table 2-7 for the appropriate valve clearances. Notes: 1. The maintenance period of the diesel generator set is calculated according to the working hours and calendar time and subjected to the first satisfaction of the regulations between the both. 2. The clients shall performance overhauling and maintenance in advance according to the actual running state of the diesel generator set. The maintenance period and items of the engine shall be appropriately adjusted according to performances such as: purpose, use state, fuel oil as well as lubricating oil, etc. 1. The requirement of standby diesel generator set is to keep rapid good starting and inputting standby state. Therefore, it is required to perform regular overhauling and following test running. Maintenance and test running of engine Run for 5-10 minutes under appropriate load each week Run for 5-30 minutes under appropriate load each week Check: Starting performance, lubricating oil pressure, exhaust, smoke as well as vibration, etc. 4. Implications of the symbols listed in the aforementioned form: ▲: Overhauling, cleaning as well as adjustment ★: Replacement of standby products ◇: When the customer can not perform overhauling voluntarily, he can contact the manufacturer behind the supplier. □ New type, overhaul and long-term seal up for safekeeping diesel generator sets, overhauling items needed to be performed after the initial 50 working hours. Fuel Oil, Lubricating Oil and Cooling Water for Machine Set 12.1. Regulations on usage of fuel oil 1. When the ambient environment is 5~35℃, 0#,-10# light diesel oil can be used. 10# light diesel oil also can be used in the southern area and -20#, -30# light diesel oil can be used in the cold area in the northern area in winter; 2. It shall be used after the fuel oil precipitates for 72 hours and the precipitation time shall not be less than 24 hours; 3. If the fuel tank is placed outside the room, there should measures for preventing rain and dust; 4. It’s not allowed to use disqualified fuel oil or use it not according to the regulations. 12.2 Regulations on Usage of Lubricating Oil The first function of the engine oil is to lubricate the moving parts. The engine oil forms hydraulic oil slick among the metal surfaces and prevents the metal components from directly being contacted and reduce friction, when the oil slick is not sufficient to avoid directly contacting the metal parts, the following situations will occur: friction generates heat, generates bonding and metal transfer will cause abrasion or obstruction. Therefore, when selecting the engine oil, the attention should be given to the following matters: 1. 15W/4℃ D level engine oil can be selected for general machine sets, some imported or joint venture’s diesel generator sets such as: Cummins, Volvo as well as Perkins, etc. should use SAE15W/40 and the engine oil with performance grade satisfying API and CF-4. 2. As for new machine or overhauled machine, all the engine oil should be exchanged after running for 50 hours. More, it is necessary to cleanse or exchange engine oil cleaner and cooler; 3. Different brand engine oils can not be used mixedly. 12.3 Regulations on Usage of Cooling Water This regulation is applicable to all series of diesel generator sets. The cooling water cycle system of the diesel generator set is one of key machine sets. For the preparation and usage of the cooling water, it arouses the user’s enough emphasis. Otherwise, the severe cooling water scale is caused the circulation area become small, the performance is undesirable and the diesel engine become exceptionally cold and hot sometimes, and a series faults such as abnormal abrasion at the early period, etc. will be led to the diesel engine. 1. Requirements for Cooling Water The most appropriate cooling water is softening, and complies with PH value: 6-8.5; hardness: 0.7-5.3meq calcium; magnesium ion/liter; chlorine ion: <150 mg/liter. Generally speaking, the purified rain water, running water or river water can be taken. It is prohibited to directly use well water, spring water and other hard water with content of high salt and high alkaline. If the user’s condition is restrained, the hard water can be used after treatment. 2. Hard Water Softening Processing Methods: Boiling method, distillation method as well as chemical treatment Several Requirements for Machine Room 1. Environmental Requirements for Machine Set Installation
1.2. There should be no conductive and corrosive gas inside the machine room; 1.3. There should no flammables and explosives surrounding the machine room; 1.4. The machine room should be equipped with lightning protection facilities; 1.5. Considerations shall be given to the fire control, overhaul and safety passage in the machine room; 1.6. Measures for noise elimination, shock attenuation, daylighting, accumulated sewage as well as discharge. EMS (Engine control system) EMS 2 stands for “Engine Management System” and is an electronic system with CAN communications (Controller Area Network) for control of diesel engines. The system has been developed by Volvo Penta and includes fuel control and diagnosis function. The system consists of a control module, six unit injectors, a number of sensors that supply the control module with measurements, sockets for diagnosis and functional checks. The engine can be connected to a communication interface comprising a CAN-link and a serial link. CAN (Controller Area Network) The CAN J1939 link handles all communication between the engine control module EMS 2 and the CIU, in addition to the diagnostics that are handled by the so called J1708/J1587 link. The CAN link is much faster than the J1708/J1587 link. The CAN link has been prepared to connect to other components with SAE J1939 protocol such as instrument panels and transmissions. If, for some reason, a fault develops on the CAN link, signals for the rpm-potentiometer and the start and stop knobs are taken over by the J1708/J1587 link. However, instrument and indicator lamps are completely turned off. If a fault occurs on both links, GE engines maintain engine speed, while VE engines go to idle. The only way to shut off the engine in this case is to use the auxiliary stop (AUX-STOP) placed on the engine’s left side. The installation of diesel generator set is important. CIU (Control Interface Unit) The CIU is a “translator” between the CAN bus and the customer’s own control panel. This unit has two serial communication links, one fast and one slow. The fast one is a CAN link that features a bus speed of 250 Kbit/ s. All data regarding instruments, indicator lamps, contacts and potentiometers are controlled by this bus. The slower J1708/J1587 link handles diagnostic information for, among other things, the flashing code. The diagnosis tool VODIA also uses the J1708/J1587 link to communicate with the system. Fuel control The engine’s fuel requirement is analyzed up to 100 times per second (depending on engine rpm). The engine’s injection amount and injection timing is controlled electronically via fuel valves on the unit injectors. This means that the engine always receives the correct volume of fuel in all operating conditions, which offers lower fuel consumption, minimal exhaust emissions etc. The control module checks and controls the unit injectors so that the correct amount of fuel is injected into each cylinder. It calculates and sets the injection angle. The control is primarily performed using the speed sensors and the combined sensor for boost pressure/charge air temperature. The control module affects the unit injectors via an electronic signal to the unit injectors’ electromagnetic fuel valve, which can open and close. When the fuel valve is open, fuel flows through the unit injector hole and out through the fuel channel. Fuel is not sprayed into the cylinder in this position. When the fuel valve closes, pressure starts to build from the unit injector’s mechanically operated pump plunger. When sufficient pressure has developed, fuel is injected into the cylinder via the unit injector’s injector section. The fuel valve is re-opened and pressure in the unit injector decreases at the same time as the fuel injection to the cylinder stops. In order to determine when the fuel valve shall open or close, the control module has access to signals from sensors and switch contacts. Calculating fuel quantity The amount of fuel that is sprayed into a cylinder is calculated by the control module. The calculation determines the time that the fuel valve is closed (when the fuel valve is closed fuel is sprayed into the cylinder). The parameters controlling injected amount of fuel are: • Requested engine speed • Motor protector • Temperature • Boost air pressure Altitude correction The control unit is fitted with an atmospheric air pressure sensor and an altitude correction function for engines operating at high altitudes. This function limits the fuel volume in relation to ambient air pressure. This is to prevent smoke, high exhaust temperature and to protect the turbocharger from over-speeding. Diagnosis function The task of the diagnosis function is to detect and locate disturbances within the EMS 2 system, to protect the engine, and to provide information about problems that have developed. If a malfunction is dis-covered, this is announced by warning lamps, a flashing diagnostic lamp or in plain language on the instrument panel, depending on the equipment used. If a fault code is obtained as a flashing code or in plain language, this is used for guidance in any trouble-shooting. Fault codes can also be read by Volvo’s VODIA tool at authorized Volvo Penta workshops. In case of serious malfunctions, the engine is shut down completely, or the control unit reduces the power output (depending on application). A fault code is set as a guide when fault tracing. In- and out signals Information from the sensors provides accurate information regarding operational conditions and makes it possible for the control unit processor to calculate the correct injection amount, injection timing and engine condition, among many other things. Input signals The control unit receives input signals regarding engine operational conditions along with information from the following components: - Coolant temperature sensor - Charge air pressure/charge air temperature sensors - Crankcase pressure sensor - Position sensor - Camshaft - Engine speed sensor - Flywheel - Piston cooling pressure sensor - Coolant level sensor - Oil pressure sensor - Oil level and oil temperature sensors - Fuel pressure sensor - Water-in-fuel sensor - Air filter pressure sensor - Air temperature sensor - Fan speed Output signals The control unit uses the input signals to control the following components: - Unit injector - Start motor - Alternator - Main relay - Preheat relay - Internal EGR (TAD1350-1355GE only) - Waste gate - Electronic fan control Instruments DCU (Display Control Unit) DCU is a digital instrument panel that communicates with the engine control unit via the CAN-link. DCU has several functions, such as: Engine control - Start, stop, rpm regulation, preheating, etc. Monitoring - Shows engine speed, charge pressure, charge temperature, coolant temperature, oil pressure, oil temperature, engine hours, battery voltage, instantaneous fuel consumption and fuel consumption (trip fuel). Diagnostic - Shows fault codes in text. Lists previous faults. Parameter setting - Idle speed, alarm limits for oil temperature/coolant temperature, regulation mode (speed droop/isochronous). DU (Display Unit) DU is an instrument for showing the engines operating values. The values are shown graphically on an LCD display. The display communicates via the CAN link and consists of a computerized unit for attachment to the control panel. It is connected to the CAN link between the engine control unit and CIU or DCU of generator set. What is The Cooling Options for Diesel Generator Set 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 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). Exhaust turbocharger is actually an air compressor that increases air intake through compressed air. It uses the inertial impulse of exhaust gas from the engine to push the turbine in the turbine chamber, the turbine drives the coaxial impeller, the impeller compressed the air from the air filter pipe to pressurize it into the cylinder. The increased air pressure and density entering the cylinder can burn more fuel, accordingly increase fuel amount and adjust engine speed, which can increase the output power of the engine. Structure: Exhaust air turbocharger is mainly made up of turbine and compressor. Because the rotor of exhaust gas turbocharger has a high speed and the parts are more precise, so it is necessary to be familiar with the structural characteristics of the supercharger when using and maintaining it. Here, we will share the specific methods of cleaning and checking the exhaust gas turbocharger. Cleaning of exhaust gas turbocharger 1. It is not allowed to clean all parts with corrosive cleaning fluid. 2. Soaking the carbon and sediment on the parts in the cleaning solution to make it soft.The thick carbon deposit on the side wall of the turbine end must be completely removed. 3. Only plastic scraper or mane brush can be used for cleaning or scraping the dirt on aluminum and copper parts. 4. If the steam impact cleaning is used, the shaft neck and other bearing surface should be protected. 5. Apply compressed air to clean the lubrication channels on all parts. Inspection of exhaust gas turbocharger Do not clean the parts before appearance inspection in order to analyze the cause of damage. The main parts to be inspected are listed below: Floating bearing Observe the wear of the end surface and the inner and outer surfaces of the floating ring. Generally speaking, after a long period of operation, the lead-tin layer plated on the inside and outside surfaces still exists, while the outer surface is larger than the inner surface, and there is a slight trace of wear on the surface of the oil groove, which is normal. The groove emitted from the working surface of the floating ring is caused by the unclean lubricating oil. If the surface is severely scraped or the measured wear limit is exceeded, it is recommended to replace the new floating ring. Middle case Observe whether there is any rubbing mark and coke deposit on the adjacent surface between the back of the compressor impeller and the back of the turbine impeller. If there is a spray phenomenon, the floating bearing has a large wear and the surface of the bearing inner hole is damaged, it is necessary to grind the inner hole with the corresponding grinding rod or gently wipe the inner hole surface with the metallographic sand skin to remove the traces of copper-lead materials adhered to the surface of the inner hole. It cannot be used until they are qualified by measurement. And analyze the cause. Turbine shaft Observe the wear of the carbon deposition at turbine end seal ring groove and the side wall of the ring groove; observe whether the inlet and outlet edges of turbine blades are bent or fractured; observe whether there is crack at the edge of the blade outlet and whether there is a curling burr caused by the rubbing at the tip of the blade; whether the back of the turbine blade is scratched or not. Compressor impeller Check the back of the impeller and the tip of the blade to avoid rubbing; check the blade for bending and breaking; check the edge of impeller inlet and outlet for cracking and scratching. Vaneless turbine shell and compressor shell Check the rubbing condition of the arc parts on each casing or whether there is scratch by foreign objects. Pay attention to observing the degree of oil deposition on the surface of each flow channel and analyzing the causes of the adverse conditions mentioned above. Elastic seal ring Check the wear and carbon deposit on both sides of the seal ring. When measuring the thickness and free state of the ring, the opening clearance should be not less than 2 mm. If it is less than the above value and the thickness of the ring exceeds the specified wear limit, it should be replaced. Thrust piece and thrust bearing There should be no obvious groove on the working surface, and check whether the oil inlet hole on the thrust bearing is blocked, and the axial thickness of each piece should be measured in accordance with the specified size range. If there are obvious wear marks on the working surface of the thrust plate and the wear limit is not exceeded, then another unworn surface of the two thrust pieces may be sequentially loaded as the working surface during reassembly. Compressor end gas seal plate and middle shell Check whether there is wear between the elastic sealing ring and the pedestal hole contact part at the turbine end elastic seal ring pedestal hole. -The generator set has good starting performance Because the EGS-02 control system realizes the closed-loop control of the running process, it ensures that the control system can be quickly controlled to a suitable air-fuel ratio state through the adjustment of the system, and the system can start quickly. Through one operator can realize the start of the unit, and do not need to adjust repeatedly, a success. The WOODWARD automatic controller system of 1100GFRQ gas generator can also realize the function of self-starting. The process is as follows: starting according to torsion-presupply oil-unit starting-idling running-rated rotational speed running-automatic grid-connected automatic load-stable operation. -Realize lean combustion, prevent intake pipe from tempering, improve efficiency and reduce heat load WOODWARD combustion control system collects signals of methane concentration and oxygen content in exhaust gas by methane sensor and oxygen sensor respectively, adjusts air-fuel ratio with high accuracy, ensures high air gas ratio and lean combustion in the best working condition of the unit. As a result of lean combustion, the generation efficiency of 1100GFRQ gas generating unit can be as high as 36% (unit heat consumption ≤ 10000 KJ / kW h), per cubic pure gas (the calorific value of pure gas CH4 is 35.9MJ / m3), then the power generation is not less than 3.6kW. -strong anti - interference ability EGS-02 combustion control system ensures that the control system will not fail due to external disturbance during operation. The intelligent IC-920 ignition control system of WOODWARD company is adopted to ensure the humanization of ignition control. -All imported components are used 16V 165RQ gas engine ignition system includes digital ignition unit, high voltage coil, high voltage line, spark plug, etc. Such as high-voltage coils, high-voltage lines are German MOTORTECH products. Advantages of EGS-02 Gas Electronic Control Technology of WOODWARD Company The ignition energy can be adjusted according to the composition of the gas in order to achieve the best igniting state. The highest level of ignition energy can be up to 50,000 volts, so that the realization of rarefied combustion becomes a reality. The ignition system has the function of overspeed protection. The upper limit of unit running speed is set in the ignition controller. Once the engine is overspeed, the ignition controller automatically stops working and the spark plug does not ignite, thus forcing the engine to stop. Play the role of overspeed protection. The ignition system has the function of automatic detection and alarm of its own faults. Once a spark plug in a cylinder does not ignite or a certain section of the line has some faults such as short circuit or bad contact, the system can detect and alarm in time, which is convenient for the maintenance and operation of the generator set. Add a single-cylinder temperature monitoring system, timely find out or replace spark plug to ensure the reliable operation of generator set. By adding the cooling water preheater of gas generating set, it can ensure the reliable start of the unit and also play a preheating protection role for each spark plug, thus prolonging the service life of the spark plug. Schematic diagram of EGS-02 coal-bed methane (gas) electronic control system of WOODWARD company The control system of 1100GFRQ gas generator adopts high and new technology as follows: -Air-fuel ratio closed-loop control technology: the main control system of the engine can accurately control the gas flow through TecJet valve according to the comparison between the actual measured parameters and the expected air-fuel ratio parameters, so as to realize the closed-loop control of the air-fuel ratio. The adoption of this technology makes the engine run more smoothly, reliably, controls more quickly and accurately, adjusts the air / gas ratio quickly, and has a wide range of heat value regulation, especially to reduce the speed fluctuation and the engine emissions when the engine is suddenly loaded with load. Both safety and economy are obviously improved. -Lean combustion technology: the engine adopts the EGS control system of the American WOODWARD company to carry on the closed-loop accurate control to the combustion air-fuel ratio of the engine, so that the engine can reach the high-altitude fuel ratio, and the lean combustion can make the engine more environmentally friendly. Higher combustion efficiency. The air-fuel ratio closed-loop control technology can keep the air-fuel ratio of the gas engine in a set range under any operating conditions, in which the mixture will not burn even when ignited without piston compression. It can effectively solve the problem of intake pipe tempering and firing, and improve the economy and safety of the engine. -Automatic grid-connected technology: automatic grid-connected; automatic power factor setting; self-electricity load setting, power output. Can automatically control the parallel operation of multiple units to achieve automatic load distribution function. -Automatic monitoring of unit operation state, automatic fault detection, remote computer monitoring, protection and other technologies can improve the actual operating power of the generator set and ensure the long-term rated 100% power generation output. -Fire detection: the engine has the function of misfire detection, which makes the engine always work in the best condition, more stable and more reliable. 6.1 General Provisions Good maintenance and repair, the key of the long-term service life of the generator set, should be carried out by the qualified technical personnel. Good record shall be made in case of maintenance and repair, which will be helpful to arranging the working procedures of maintenance and repair in the future. In general, the generator set shall be kept clean without liquids such as: fuel oil or lubricating oil piled up on any internal or external surfaces and on the surface of, under and around the sound absorption (if the device is available) materials. The industrial water solvent shall be used to clean the surface of the machine, but the flammable solvents can not be used for cleaning. For instance, the protection of the sound absorption material is torn down or penetrated, it should be replaced immediately so as to prevent the liquid or oils penetrated and accumulated on the material. 6.2 Preventative Maintenance For the situations of the use of generator set is not the same, the requirements for maintenance are different. For the detailed maintenance of the diesel engine, please refer to Manual for Diesel Engine. For it is associated with this chapter, the use shall read the relevant parts to practice by combining this chapter. The maintenance work can be performed more frequently than that according to the requirements of this chapter. 6.2.1 Daily maintenance and after-star-up maintenance per time: for the prepared generator set, these procedures can be performed once to visually check the surrounding area of the machine before start-up per time or day. The check before start-up specified in section 5.2 shall be performed here at the same time. For the check procedures of the diesel engine, please refer to Manual for Diesel Engine, in which the requirements can be seen the supplement of the section 5.2. 6.22 Check (referring to the reserve machines not always started) the machine every two weeks and start the machine to run for five minutes. WARNING! Do remember not letting the diesel machine run under low load. 6.2.3 Check (referring to the reserve sets running without load increased) and start the machine to make run for five minutes and increase at least 50% load to run for 1-2 hours every month. 6.2.4 Check every 6 months or 250 hours: 1. Check the protective devices of the control system by adopting fault simulation method. 2. Clean the exhaust hole. 3. Tighten all connectors of the exhaust pipe 4. Tighten all connects of the electrical equipment. 5. Perform other special maintenance of the diesel machine listed in the Manual for Diesel Machine. 6. Observe all instruments on the control screen to see if the running is normal after starting the machine. 6.2.5 Preventative maintenance of alternator: it’s not necessary to perform daily maintenance of the alternator but it is required to check and clean the coil of the alternator regularly. Please to refer to the maintenance of alternator and Alternator Manual specified in section 8.2. 6.2.6 Preventative maintenance of alternator: in line with the requirements provided by the Manual for Diesel Engine, read this manual and perform frequent maintenance to maintain its highly efficient performance. 6.3 Dismantlement of Generator and Alternator Dismantlement of diesel engine or alternator shall be started according to the following procedures: 1. Dismantle the circuit from power supply to the auxiliary equipment (such as: hot water jacket). 2. Disconnect the circuit for battery charging and battery wire (firstly dismantle the cathode), and move battery if necessary. 3. Provided that the generator has cap, then it is necessary to loosen the bolts fixed at each side of the cap, dismantle the exhaust pipe, and then move the cap away. 4. When dismantling the control screen, it’s necessary to dismantle all lines & bearers and fully ensure all the lines can be connected again. 5. If the diesel engine and alternator are dismantled, the rings of the diesel engine and alternator can be used to life them independently. But the bolts fixed at their chassis initially. 6.3.1 Only Dismantle Diesel Engine 1. In case of only dismantling the diesel engine, the hose pipe of the circuit on the diesel engine shall be dismantled initially. 2. Provided that the only foot of alternator is at the chassis, the front end of the alternator shall be stationed well by using the bearer when dismantling the diesel engine. 3. Removing the chassis bolt on the diesel engine and loosening the fixed bolt of the alternator might be helpful to dismantling diesel engine. 4. Remove the protection cover of the fan of alternator. 5. Use lifting hook or wooden bearer to hold it up, be careful and don’t destroy fan blade. 6. Dismantle the diesel engine and alternator 7. Use the elevated crane or similar devices to lift it at the end of the diesel engine. 8. Dismantle the bolt of joint shell. 9. Now, move the generator forward until it is completely separated from alternator and the chassis can be lifted away. 5.3Initial start/stop----Automatic start control panel (initial start and stop) 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.
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 machine: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. Air Filter
The dust in the air is the primary reason on abrasion for cylinder liner, piston, piston ring, valves, valve stem guide and other athletic parts, the more the dust in the intake to the engine is the more the abrasion of the engine’s parts is. It is founded by wearing test of engine that the dust less than a diameter 0.001 mm has an very small effect on engines, the dust with a diameter between 0.001 mm and 0.01 mm has measured effect on the engine if the diameter of the dust in the intake is larger than the thickness of the bearing oil film, it will affect the life of the main and connecting bearing and the piston ring. Therefore, to extend the service life of a diesel generator, it is very important that air filter should be chosen carefully. According to different uses, air filter is divided into normal duty and heavy duty air filters. The minimum efficiency for normal duty cleaner at any flow between 15% and 100% at the rated air flow is 99.5%; and its minimum dust holding capability is 3.0 gram/CFM( or 6A gram/L.S) at rated air flow, it will be applied primarily to those generator drive engines and marine engines. The minimum efficiency for heavy duty filter at any flow between 15% and 100% of the rated air flow is 99.9% and its minimum dust holding capability is 25.0 gram/CFW (or 53 gram/L.S) at rated air flow, it will be applied primarily to the mining product, construction product, automotive product, off-high heavy duty, etc. Those engines ( and generator drive engine) and marine engines ( and generator drives engines). After the air cleaners have been used for period of time, its elements will be dirtied, and restriction of the air intake will increase. When the restriction increases to above 6.25kPa, the engine can not get sufficient air. Therefore, the engine will discharge the black smoke and the engine’s power will be own. The customer can estimate the air-logged conditions of the air filter by the air induction indicator or annunciator, if the indicating window of the indicator changes from green to red, or the annunciator gives an alarm, the air intake restriction had exceeded the limit valve, and the element will need to be cleaned up or replaced. The following methods can be used to clean up the element of the air filter: a. Lightly knock the end plate & the element to shake off the dust accumulating on the element; b; Open the dust discharging jaws on the air cleaner to remove the dust in the air cleaner shell. c. Open the end cover of the cleaner and pull out the element. d. Clean up the element with the dry compressed air. Note: a. It is not permitted to clean up the element with oil or water. b. For the heavy duty air filter, there are many convolute pipes, these pipes can not be taken down, and it can be washed up with hot alkaline water, flush it with cleanly water, then blow it with compressed air. c. The secondary ( or safety) element of the heavy duty air cleaner can not be cleaned up. When the following problems are founded, the primary element must be replaced with a new element. a. The primary element is in disrepair. b. After assembly the element, the indicator indicates red or the annunciator for gives an alarm again. c. The primary element have boon cleaned up for five times. Note: For heavy duty air filter, when its primary element is disrepair or cleaned up for five times, its secondary must be replaced. |
作者
dieselgenerator 存档
July 2022
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