الفهرس 
REVIEW OF LITERATUREOnly 14 pages are availabe for public view
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Abstract
Diesel engine have an important role in agriculture sector. Diesel water pumps are more spreading in Egypt that arrived up to (188, 6382). The Kerloscar type was represented by 22% from the total water pumps in Egypt. Injection pressure for diesel engines is the most important factor which effects on the performance and efficiency of engine. The main objective of this study was: modified the injector tester device from manual operation to mechanical operation to reach the uniformity of the pressure during injectors test, install of reading, save time, save fuel consumption and accurate of testing.
The main results in laboratory and field tests were as follows:
1- The injector tester device has been modified from manual to mechanical in order to stabilize the number of injection strokes and to give regular results that do not depend on the operator voltage to be more accurate.
2- The mechanical injector tester device was saving fuel consummation more than manual injector tester this is due to the regularity of the motion in the mechanical device but the manual device that is depending on the operator and the irregularity of motion which cause irregularity of pressure.
3- Glycerine gauge with the modified device was better than manometer with manual device because it has higher accuracy reading pressure than manometer with the manual device.
4- The type of pressure gauge was effecting on the injector tester device before and after modification.
The pressure was variable between (210-225 bar). It was non stability with injector tester device before modification in each external workshops (atlas, Al-Monib) which measured by normal manometer. When used Glycerin manometer the pressure was 175 bar that was stability with injector tester device after modification.
5- Evaluate the injector tester device before modification was run in external Workshops.
- The pressure was unstable during the test. Reading on the pressure scale was oscillated between up and down. This indicates inaccuracy of reading pressure.
- Four different injectors was used in this study to evaluate any tester device before and after modification.
- The fuel consumption was increased with injector tester device of Atlas workshop than injector tester device of Al-Monib workshop with standard injector but the fuel consumption was decreased with injector tester device of Al-Monib workshop than atlas workshop injector tester device with injector 2. The same results were different by increasing or decreasing with injector 3 and 4. This is due to irregular pressure due to manual operation of each device.
6- Evaluate the injector tester device after modification was run on the four different injectors with eight different pressures. The results were recorded with fuel consumption, spray pattern, spray angles and fuel infusion.
- The Pressure gauges (glycerin gauge) was used to test four injectors at the following different pressures (100،110,120,130,140,150,160,175 bar).
- The main purpose of the fuel injection system is delivering fuel to an engine cylinders. The amount of fuel is important due to its effect on the efficiency of combustion so the timing of injection must be suitable for the amount of desired of fuel. The results of fuel consumption (L / h) with the four injectors were taken at 8 different pressures.
- The results of the fuel consumption for the standard injector(1) were stable to (0.66 L / h) at different 7 pressures from (100 to 160 bar) but increased 10.6% with pressure 175 bar because most of the water pumps operate at optimum pressure between 140 to 160 bar.
- The fuel consumption for injector (2) were unstable and different with each pressures because it had bad nozzle. The fuel consumption of injector 2 was compared with standard injector at different pressures as 100, 140, and 175 bar the results as percentage were 10.6%, 12.1% and 28.8% respectively. Injector 2 after changing the bad nozzle was compared with injector (2) before changing nozzle and the standard. After changing of nozzle, the fuel consumption was reduced but did not reach optimal consumption as the standard injector. The efficiency of the standard injector was compared with the injector 2 before and after changing the nozzle.
- The fuel consumption of injector 3 was compared with standard injector at different pressures to show a difference of fuel consumption as percentage. The injector 3 after changing the bad nozzle was compared with injector (3) before changing nozzle and with injector standard.
- The fuel consumption for injector (4) was few. The difference between injector 4 and standard injector as the percentage and at different pressures 100, 140, 160, 175 bar were 16.9%, 22.1%, 24.2 and 30.1% respectively.
The injector needle was damaged. The fuel consumption of injector 4 after changing nozzle was compared with the standard injector at different pressures.
The efficiency of the standard injector was compared with the injector (4) before and after the nozzle changed.
7- Leak test was run with four injectors with different pressure as follow:
Standard injector: there was not appeared any leak with all different pressures.
The injector (2): there was not appeared leak with pressures (175,160,150 bar) but at pressures (100,110,120,130,140 bar) event leak.
The injector (3): there was appeared leak with all pressures except test pressure (100 bar).
The injector (4): there was leak with all test pressures.
8- The spray pattern test (fuel spray)
The spray pattern is important for combustion and mixing air process. The results were with different injectors as follow:-
- Standard injector form the perfect spray pattern for fuel that should be atomized and appear as a fine mist.
- The injector (2): the spray pattern is characterized by dispersion and not acceptable at the operating pressure (140 bar). Also a fuel cone is not good at the pressure (110,100).
- The injector (3): The spray pattern is characterized by dispersion and not acceptable at all pressures.
- The injector (4): the spray pattern was not good at all pressures. The large diameters from fuel droplets were appeared with fuel cone. So, it is necessary to repair injectors 2, 3 and 4 by changing the nozzles to arrive of optimal spray cone.
9- from the previous results showed that the injection angles increase when leakage and dispersion of injection were increased. Also, causes bad combustion and increase the harmful emissions from co, co2 and other exhaust gases.
10- In the field tests the modified tester device was proved the ability to measure the pressure, follow the characteristics of the injector and define the defect in the injection system.
11- CO was increasing with injection pressure less or higher than the operating pressure. At the minimum operating pressure the ratio of CO is 1.56%. At the maximum injection pressure CO is 1.74%. At the standard injector, CO was 1.38%.
12- The specific fuel consumption test The results were follow:-
- Injector standard (1): The specific fuel consumption in the field was 252.39 g/kWh.
- Injector (2): The specific fuel consumption in the field was 188.57 g/kWh.
- Injector (3): The specific fuel consumption in the field was 275.61g/kWh
- Injector (4): The specific fuel consumption in the field was (0).
The specific fuel consumption was calculated from the fuel consumption values. The specific fuel consumption was effected by operating pressure and state of the injectors.
Compare the device before and after modification was:
Injector tester
device Comparisons
Before modification
After
modification
Operating system Manually Mechanical
Pressure gauge Normal Glycerin
Pressure reading Non stability Stability reading
Filter system None Available
Accuracy Lower Higher
Time test Variable Fixed
Measurement of -Fuel con.
-Injection p. -Fuel con.
- Injection p.
- infusion
-Spray pattern
-Spray angle
RECOMMENDATIONS
1- The injector tester device can be used for detecting and evaluating the failure of the injectors in the laboratory or the field. Also can be followed and adjusted the pressure during operation.
2- Must be conducted a periodic maintenance of injectors.
3- Recommended to use pressure glycerine gauge with any tester device.
4- Installation of a standard injector on the tester injector device with the injector tester to be easy to compere between the failure injector and standard injector.