Exhaust Emission

Why the cooling of IC engine is necessary? Explain how cylinder size affects engine heat transfer?

Explain the effects of load on $NO_x$ emission from CI engine.

Estimate heat loss of 12 cylinder gasoline engine operating at $590 \text{ kW}$, fuel-air ratio $= 0.08$, inlet air temperature $= 27^\circ\text{C}$, gas temperature $= 400^\circ\text{C}$. The engine is of $145 \text{ mm}$ bore and $145 \text{ mm}$ stroke, brake thermal efficiency $= 0.25$. Calculate heat loss per unit piston area, ratio of heat loss to heat of combustion. Heat of combustion of gasoline fuel $= 42 \text{ MJ/kg}$, $\mu_g = 32.5 \times 10^{-6} \text{ kg/m-s}$ and $k_g = 0.12 \text{ kW/m-K}$.

Why cooling of IC engine is important?

How unburn hydrocarbon emissions are occurred in SIE?

A diesel engine operating on the 4-stroke cycle is to be designed to operate with the following characteristics where the mean conditions are: 1 bar and $25^{\circ}\text{C}$; brake power 254 kW; volumetric efficiency = 0.77; brake specific fuel consumption = 0.26 kg/(kW.hr); air-fuel ratio = 17:1; speed = 1500 rpm. Calculate the required engine capacity and brake mean effective pressure. Heat of combustion of diesel fuel = 43,000 kJ/kg, $R_a = 287 \text{ J/kg.K}$.

What is scavenging? Explain the scavenging process with cylinder pressure vs. crank angle diagram.

Why larger engine is more efficient?

How mechanical supercharging process is different from turbocharging?

Why is diesel engine $\text{NO}$2/\text{NO}{\text{x}} decreases with the increase of load?

What is scavenging? How perfect mixing is different from complete short circuiting? When complete short circuiting could happen during the scavenging process?

How CO forms in SI engine combustion? According to Bangladesh vehicular emission standards what is standard value of CO emissions from petro/octane vehicles.

Estimate heat loss of 12 cylinders gasoline engine operating at 600 kW, fuel-air ratio = 0.08, inlet air temperature = 27°C, coolant temperature = 50°C, gas temperature = 400°C. The engine is of 146 mm bore and 146 mm stroke. Brake thermal efficiency = 0.23. Compute heat loss per unit piston area, ratio of heat loss to power, and ratio of heat loss to heat of combustion. Heat of combustion of gasoline fuel = 42 MJ/kg, $\mu_g = 32.5 \times 10^{-6}$ kg/m-sec, $k_g = 51.96 \times 10^{-6}$ kW/m-K.

What is supercharging? How is it achieved?

How can constituents of exhaust gases be controlled? Describe briefly.

Why does CI engine exhaust gases contain insignificant amount of CO?