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HỘI THẢO QUỐC TẾ ATiGB LẦN THỨ CHÍN - The 9 ATiGB 2024 59

propagation, posing challenges to engine operation and Displacement Volume
performance optimization. (dm ) 0.163 0,183
3
To overcome these limitations, several measures are Mean Effective
proposed. First, adjusting the engine’s compression Pressure ( MN ) 0,838 0,8696
m 2
ratio by modifying the piston diameter can increase The displacement volume of the cylinder after
pressure and temperature in the combustion chamber, improvement is calculated as:
enhancing NH3 combustibility and improving
3
2
combustion efficiency. Second, altering the piston Vh= ×D ×S= 183217 mm
4
crown shape can also influence the combustion process Since the maximum power output for the gasoline
and flame propagation. By optimizing these factors, we engine, as per the manufacturer, is achieved at 3600
can improve the performance and reliability of engines rpm, the research team also chose 3600 rpm when
using NH3 while minimizing the disadvantages switching to NH3 fuel to simplify the calculations and
associated with NH3 poor combustibility and slow simulations. For practical experiments and further
flame propagation. calculations, adjustments will be made accordingly.
2. RESEARCH CONTENT
The work produced by the working fluid in the
2.1. Research Subject
cylinder during each cycle is determined based on the
The research was conducted on a Honda GX160 p-V diagram. Therefore, the p-V diagram is called the
engine, with technical specifications shown in Table 1. work diagram, and this work is known as the indicated
Table 1. Specifications of the Honda GX160 Engine power of the cycle Li.
Engine Type Gasoline, 4-stroke, 1-cylinder Indicated power Li before improvement using
Number of Cylinders 1 gasoline:
Cylinder Bore (mm) 68
-4
6
6
Piston Stroke (mm) 45 Li= 10 .pi.Vh=10 .0,94 .1,63343 .10 = 153,542
Displacement (cm³) 163 (N.m)
Compression Ratio 8,5:1 Indicated power Li after improvement using NH3:
Maximum Power (kW/rpm) [11] 4,1/3600
Maximum Torque (N.m/rpm) 10,3/2500 Li= 10 .pi.Vh=10 .1,01 .1,83217 .10 = 185,049
6
-4
6
Fuel Tank Capacity (liters) 3,1
(N.m)
2.2. Improvement of the Piston-Crankshaft-Connecting The number of cylinders in the engine is denoted by
Rod System
i and the indicated power Ni (N.m/s hoặc W/s) of the
The air-fuel (A/F) ratio for NH 3 fuel is 6.05 [10]. engine is calculated as follows:
Assuming the combustion chamber is fully charged and 2π
combustion is complete, the amount of NH 3 intake per Ni = m .i . Li = . i . Li (1)
τ
cycle is calculated to be 2.888 × 10⁻³ dm³. The Assuming the displacement volume Vh of all
compression ratio corresponding to NH 3 RON of 130 is cylinders is equal:
within the range of ε = 10 to 15 [9]. The design to
increase the compression ratio should be based on the Vh∑ = i . Vh (2)
limiting value of ε. In this study, the Honda GX160 Therefore, Equation (1) can be rewritten as:
engine was selected for improvement. This is a small Ni = . Pi. Vh . i . n (3)
2
stationary engine. For this engine, the research team τ
chose a compression ratio of ε = 10, which is within the Where Pi is calculated in MPa (MN/m²), Vh in liters,
safe range for the components and suitable for using n in revolutions per minute (rpm), and power N in kW:
NH3 as fuel. According to previous studies on NH3, the Ni = Pi . Vh∑.n (4)
combustion chamber temperature T c must exceed Pi . Vh∑.n
657°C to maintain stability and efficiency in NH 3 Ni = 30τ (5)
combustion [10]. Indicated power Ni from the Honda GX160 Engine:
Table 2. Input Parameters Pi . Vh.. i . n 0,94 . 0,163 . 1 . 3600
Ni= = = 4,631 (kW )
Before Improvement After Improvement 30τ 30 . 4
(Gasoline) (NH 3) Indicated power Ni of the Honda GX160 engine
Compression Ratio 8,5 10 after improvement:
Piston Diameter (mm) 68 72 Pi . Vh.. i . n 1,01 . 0,183. 1 . 3600
Ni= = = 5,545 (kW)
Piston Stroke (mm) 45 45 30τ 30 . 4
Effective power (Ne) from the Honda GX160
Mean Indicated engine:
Pressure ( MN ) 0,94 1,01
m 2
ISBN: 978-604-80-9779-0