Black smoke emitted from diesel engine exhaust is a phenomenon caused by incomplete combustion of diesel, which decomposes into carbonaceous material under high temperatures and is expelled with the exhaust gases. Black smoke not only reduces engine power and increases diesel consumption, but also tends to form carbon deposits, shortening the engine's lifespan. The reasons are as follows:
Insufficient fresh air in the cylinder
Reasons: (1) Excessive accumulation of dust in the air filter element; (2) Rust, carbon, or oil污 on the muffler; (3) Excessive gap in the intake and exhaust valve clearances, reducing valve opening; (4) Loose, worn, or deformed parts in the camshaft gear and crankshaft timing gear, leading to incorrect valve opening and closing times.
The reason for the decrease in temperature and pressure at the end of the cylinder compression
(1) Excessive cylinder liner and piston ring wear, incorrect piston ring installation, or loss of elasticity leading to cylinder leakage; (2) Insufficient valve clearance, prone to being popped open during hot operation, or valve burning and carbon accumulation resulting in poor cylinder sealing; (3) Gas leakage at the cylinder head and engine block, as well as the injector and cylinder head mating surfaces; (4) Severe valve depression, excessive gaps between the piston and piston pin, the piston pin and connecting rod small end, and the connecting rod big end and connecting rod journal, increasing combustion chamber volume and reducing compression ratio.
III. Poor Diesel Atomization
Reasons: (1) Low injector pressure adjustment; (2) Broken or stuck injector pressure spring; (3) Carbon buildup on the injector nozzle valve and seat, causing sticking or excessive wear of the nozzle valve; (4) Excessive wear on the fuel pump's outlet valve relief ring, leading to dripping from the injector.
Four: Incorrect fueling time and fuel quantity
The reasons are: (1) late fuel supply; (2) low gas pressure and temperature at the initial start-up, with early fuel supply; (3) increased fuel supply stroke after the wear of the fuel pump plunger assembly; (4) excessive stroke of the fuel pump adjustment lever or rod, leading to an overabundance of fuel supply.
How is a generator regulator adjusted?
1. Adjustment of the closing voltage
Connect a dry cell, a battery, and an ammeter in series, and attach them to the battery terminals of the regulator. Start the engine and gradually increase the RPM, observing the ammeter needle on the tractor as the circuit breaker contacts close. If the ammeter needle swings towards the "+" side, it indicates a high closing voltage, and the spring tension should be reduced; if the needle swings towards the "-" side, it suggests a low closing voltage, and the spring tension should be increased. Continue adjusting in this manner until the ammeter needle barely moves when the circuit breaker contacts close, indicating an appropriate closing voltage.
2. Pressure Regulation Adjustment
Connect two dry cells in series with a battery and an ammeter, and then attach them to the battery terminals of the regulator. Start the engine and gradually increase the engine speed. Observe the ammeter needle as the voltage regulator begins to function. If the ammeter needle swings towards the "+" sign, it indicates the voltage is too high, and the spring tension should be reduced; if the needle swings towards the "-" sign, it means the voltage is too low, and the spring tension should be increased. Continue this adjustment process until, when the voltage regulator is active, the ammeter needle barely moves, indicating the voltage setting is appropriate.
The principle of this adjustment method is that when dry cells and lead-acid batteries are connected in series, they possess a certain potential difference. The generator produces a specific voltage, and an electric current is generated when these two are not equal. If the potential of the former is higher than the latter, the current meter needle points towards the "-" direction; conversely, it points towards the "+" direction. Only when both have similar potentials does the current meter needle remain stationary.
