Experimental Study on Diesel Engine Emission Characteristics Based on Different Exhaust Pipe Coating Schemes

Area of Science:

• Materials Science
• Mechanical Engineering
• Environmental Science

Background:

• Diesel engine exhaust systems generate significant heat, impacting performance and emissions.
• Effective thermal insulation of exhaust pipes is crucial for optimizing engine efficiency and reducing environmental pollutants.

Purpose of the Study:

• To evaluate the thermal insulation performance of exhaust pipes coated with basalt and glass fiber materials.
• To assess the impact of different braiding forms (sleeve, winding, felt) on insulation and emission characteristics.
• To compare the effectiveness of basalt versus glass fiber materials in reducing diesel engine emissions.

Main Methods:

• Engine bench tests were conducted to measure thermal insulation and emission characteristics.
• Exhaust pipes were coated with basalt and glass fiber materials in sleeve, winding, and felt forms.
• Key performance indicators included temperature drop and gaseous pollutant conversion rates (NOx, HC, CO).

Main Results:

• Basalt fiber coatings exhibited higher thermal insulation than glass fiber, with a notable advantage during the engine's idle cold phase.
• Felt-type braiding provided superior insulation, showing greater temperature decreases compared to sleeve and winding types.
• Basalt fiber materials significantly improved gaseous pollutant reduction, with higher NOx, HC, and CO conversion rates than glass fiber, especially during idling.

Conclusions:

• Basalt fiber materials, particularly in felt-type braiding, are highly effective for diesel engine exhaust pipe thermal insulation.
• These materials contribute to substantial reductions in harmful gaseous emissions (NOx, HC, CO) during critical engine operating conditions.
• While effective for gaseous pollutants, the tested coatings did not significantly alter particulate matter emissions.