Необходимые детали
номер спецификации:SCR000-1
Введение в продукт
Selective Catalytic Reduction (SCR) is a highly efficient emissions control technology designed to reduce nitrogen oxides (NOₓ) from diesel engine exhaust. As a core component of modern diesel aftertreatment systems, it plays a pivotal role in meeting strict global emission standards and mitigating air pollution.
The SCR system operates by injecting a urea-based reductant—commonly known as Diesel Exhaust Fluid (DEF) or AdBlue—into the exhaust stream. At an optimal temperature range of 200-400°C, the reductant vaporizes and reacts with NOₓ on the surface of a specialized catalyst (supported by cordierite or silicon carbide substrates). This selective chemical reaction converts harmful NOₓ into harmless nitrogen (N₂) and water (H₂O), with minimal impact on other exhaust components.
Widely adopted in diesel-powered trucks, buses, construction machinery, generators, marine vessels, and industrial engines, SCR systems typically integrate with DOC (Diesel Oxidation Catalyst) and DPF (Diesel Particulate Filter) for comprehensive pollutant control. Together, these devices ensure compliance with standards such as Euro 4/5/6, EPA, and China VI, achieving NOₓ conversion efficiencies of 90% or higher while enabling efficient engine operation.
Basic Information
- What is Selective Catalytic Reduction (SCR)?It is an emissions control technology for diesel engines that reduces nitrogen oxides (NOₓ) into harmless nitrogen (N₂) and water (H₂O) using a catalyst and reductant.
- How does SCR work?A reductant (typically urea-based AdBlue/DEF) is injected into exhaust gases, vaporizes, and reacts with NOₓ on the catalyst surface at 200-400°C, converting pollutants without major side reactions.
- What are the core components of an SCR system?Key parts include a reductant (AdBlue/DEF) storage/injection system, SCR catalyst (on cordierite/SiC substrate), mixing chamber, and NOₓ sensors/ECU for control.
Application & Function
- Which equipment uses SCR systems?Diesel-powered trucks, buses, construction machinery, generators, marine vessels, and industrial diesel engines.
- What pollutants does SCR target?It specifically reduces nitrogen oxides (NOₓ), including nitric oxide (NO) and nitrogen dioxide (NO₂)—major contributors to smog and acid rain.
- How does SCR integrate with other aftertreatment devices?It is often paired with DOC (for pre-heating/oxidation) and DPF (for soot removal) to meet comprehensive emission standards.
Usage & Maintenance
- What reductant is used for SCR?Urea-based Diesel Exhaust Fluid (DEF) or AdBlue—chemically 32.5% high-purity urea in deionized water.
- How to maintain an SCR system?Use only certified DEF/AdBlue; keep the injection system clean; follow service intervals for catalyst inspection; avoid contamination of reductant.
- What causes SCR system inefficiency?Low exhaust temperature (below 200°C), poor reductant quality, catalyst poisoning (sulfur, oil ash), or clogged injectors.
Performance & Specifications
- What is the typical NOₓ conversion efficiency of SCR?Can achieve ≥90% NOₓ reduction under optimal operating conditions.
- What is the service life of an SCR catalyst?Generally 200,000-400,000 km, depending on fuel quality, reductant use, and operating conditions.
- Are SCR systems compliant with emission standards?Yes. They are mandatory for meeting Euro 4/5/6, EPA, China VI, and other global diesel emission regulations.