الفهرس 
REVIEW OF LITERATUREOnly 14 pages are availabe for public view
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Abstract
Energy demand in the Egyptian countryside is high and growing as a direct result from economic development and population growth. Because of depleting fossil fuel resources, alternatives to petroleum derived fuels for the internal combustion engines need to be found. Compressed natural gas (CNG) can be such an alternative fuel because is much more abundant than petroleum (Andrei et al., 2019). In recent years, natural gas has been viewed as a clean alternative fuel for Spark Ignition (SI) engines due to its relatively high octane number. The light combustion of natural gas, which contains mostly methane, in SI engines would have improved thermal efficiency and reduced emissions compared to gasoline.
5.1. Objective:
1. Convert SI engine to power a water pump for irrigation by using natural gas.
2. Design a gas mixing device natural gas into air stream.
3. Compare the output power of using natural gas with fuel gasoline.
4. Reducing pollution resulting from exhaust gas.
5. Reducing the costs needed to operate the engine and irrigation pump.
5.2. Experimental factors:
Through the preliminary experiments, the experimental factors can be determined in the average of the experiments, and the factors were as follows:
1. Type of fuel: two types of fuel were used (gasoline - natural gas) to run the engine and the water pump.
2. Operating the engine: the pump was operated once with a load and once without a load for all used speeds and for all types of mixers and types of fuel (gasoline - natural gas).
3. Engine speed: where four speeds were used for the motor shaft (1750-2300-2900-3500 rpm)
4. Gas mixing method: seven types of mixers were used (90 angle T mixer - 45 angle T mixer - 30 angle T mixer - venture mixer - 8cm perforated inner tube mixer - 10cm perforated inner tube mixer - Mixer With a perforated inner tube of length 12 cm )and it can be expressed by (T90, T45, T30, VM, L8, L10, L12).
5.3. Experimented measurements:
Many measurements were made in the experimental workshop at the Agricultural Engineering Department, Faculty of Agriculture, Ain Shams University, Egypt.
5.3.1. Engine power:
where results guarantee that the relationship between engine speed and actual power is a quadratic relationship, As we note with the increase in the engine speed, the power increases in all types of mixers. The actual power is superior to all types when operating with gasoline A comparison with the use of natural gas, where the mixer type (T45) gave the highest power compared to the types of mixers (2.83 kW) at an engine speed of (3500 rpm) was 7.5% less than gasoline.
5.3.2. Specific fuel consumption:
where results guarantee that he lowest (S.fc) at an engine speed of 2900 using gasoline was (219.025 g/kW.h) and using natural gas when the type of mixer T45 was (234.61 g/kW.h) an increase of 6.6 % over gasoline. The lowest (S.fc) at an engine speed of 2900 rpm using natural gas when the type of mixer L10 was (340.144 g/kW.h) an increase of 35.6 % over gasoline.
5.3.4. Exhaust gases:
The results guarantee the percentage of CO2 exhaust gases when operating with gasoline exceeding all types it was (7.96%) and the lowest percentage carbon dioxide was ( 4.22%) using mixer type L12. The results the percentage of CO exhaust gases when operating with gasoline exceeding all types it was (0.53%) and the lowest percentage carbon monoxide was ( 0.18%) using mixer type T30.
5.3.5. Power and discharge of the pump:
The hydraulic power when the engine is operating with gasoline and natural gas for all types of mixers at an engine speed of (3500 rpm), the highest hydraulic power was when operating with gasoline (0.89 kW), then the mixer T45 was (0.798 kW), while lowest the hydraulic power was at the L12 mixer (0.473kW).
The results guarantee the relationship between pressure and pump discharge is inverse, as the higher the pressure, the lower the pump discharge. Maximum discharge using gasoline (32.38 m3/h) at pressure (0.2bar) and minimum discharge (5.66 m3/h) at pressure (1.8 bar) at engine speed (3500 rpm)
The results guarantee maximum discharge using T45 mixer (33.09 m3/h) at pressure (0.2bar) and minimum discharge (3.60 m3/h) at pressure (1.8bar). Maximum discharge using L12 mixer (29.51m3/h) at pressure (0.2bar) and minimum discharge (2.18 m3/h) at pressure (1.8bar). at engine speed (3500 rpm)
5.4. Economic indicators:
• Net present value (NPV):
Net present value (NPV) with a load for each of (Gasoline, T30, T45, T90, VM) that the lowest (NPV) was the mixer type (T90) was (77219.5), and the highest (NPV) when carrying the mixer type (T45) was (106900.7). Net present value with a load for each of (Gasoline, L8, L10, L12) that the lowest (NPV) was the mixer type (L12) was (78791.4), and the highest (NPV) when carrying the mixer type (L10) was (108893.8).
• 5.6.2.Benefit cost ratio (B/C):
Benefit cost ratio (B/C) with a load for each of (Gasoline, T30, T45, T90, VM) that the lowest (B/C) was the mixer type (VM) was (1.38), and the highest (B/C) when carrying the mixer type (T45) was (1.54). Benefit cost ratio (B/C) with a load for each of (Gasoline, L8, L10, L12) that the lowest (B/C) was the mixer type (Gasoline) was (1.39), and the highest (B/C) when carrying the mixer type (L10) was (1.56).
• Payback period:
The time needed for the project to recover the net return (benefits) the cost of the capital investment for the project. The capital payback period for each of (Gasoline, T30, T45, T90, VM) that the lowest payback period was the type of mixer (T45) was (1.7 year), and the highest payback period When the (VM) mixer, it was (2.37 year). the capital payback period for each of (Gasoline, L8, L10, L12) where we note that the lowest payback period was the type of mixer (L10) was (1.66 year), and the highest payback period When the (Gasoline) mixer, it was (2.27 year).
• Economic all efficiency:
The results guarantee the lowest economic efficiency was the type of mixer (T90) and gasoline was (1.65), and the highest economic efficiency when the (T45) mixer, it was (1.83). The economic efficiency when the (L8) mixer was (1.85).
CONCLUSION AND RECOMMENDATIONS:
from obtained results of this study to solve the deterioration of fuel economy by using natural gas , The goal of tis to improve the fuel/air mixing and combustion process, this study and the main conclusions were summarized as below:
1. Gasoline engines can be converted to work with natural gas with a power efficiency of up to 90%.
2. The highest pump discharge was with the T45 mixer (33.09 m3/h), an increase of 2.1% over gasoline at an engine speed of (3500 rpm).
3. The highest actual power with L10 type mixer compared to other type L mixers (2.69 kW) was 10 % lower than that of gasoline.
4. The highest actual power with T45 type mixer compared to other type T mixers (2.83 kW) was 7.5% less than gasoline.
5. As for the economic indicators, the use of natural gas gave a good economic return for all mixers, and the best economic indicators were for the mixer (L10) an increase of 26.6 % over gasoline.
We recommended that:
• Use (L10) mixer to reduce fuel consumption and increase the engine power and actual hydraulic power to mix natural gas with air.
• Use (T45) mixer to reduce fuel consumption and increase the engine power and actual hydraulic power to mix natural gas with air, It gave better results than the (L 10) mixer.
• We recommended that in further testing to measure engine life using natural gas due to cheap price and it reduces polluting gases.