Emission regulation trend of On-Off Highway equipment
The nationwide bus and freight trucking industry has proposed to the government the suspension of emissions standards that have been in force since 2015. The main reasons are the sluggish development of domestic automobiles, vehicle price increases, maintenance of the Selective Catalytic Reduction (SCR) aftertreatment system, and the unstable supply of vehicles. Emissions regulations for construction equipment have also been strengthened since 2015. However, major OEMs have already completed the development of new equipment and are ready for export to developed countries and domestic supply. Let's look emission regulation trends and the technology of Cummins.
Regarding the diesel engine, despite the advantages of its strength and excellent fuel efficiency, regulations are being strengthened as harmful emissions are comparatively higher than other fuels such as CNG and LPG. In terms of the environment, technology development and financial investment are actively promoted globally in order to minimize emissions. In accordance with the strengthened emission regulations, domestic companies are also spurring efforts to develop products that meet environmental standards for export. Cummins is an industry-leading eco-friendly engine company. In 2005, we developed the world's first engine for construction equipment that meets Tier 4 Final.
Euro 6 regulations for large trucks
It has been 20 years since Euro 1 emissions regulations for trucks and buses (over 3.5 tons in total), were introduced for the first time in Europe. Since then, enhanced emissions regulations have been introduced in order of Euro 2 in 1996, Euro 3 in 2000, Euro 4 in 2005 and Euro 5 in 2008. The most recent emission regulation was released in 2013 and included particle counts. Korea introduced somewhat less strict standard with following Euro 1 & 2 with combining 13 mode of Japan until 2002.
Since 2003, we have adopted Euro 3, Euro 4 in 2006 and Euro 5 in 2009, and from early 2014 we applied the Euro 6 standard to new certified large trucks for the first time in the world except Europe.
New emissions regulations which applied to domestic large sized trucks in 2014 require an additional Particulate Number in addition to existing emission standards (CO, HC, NOx, PM) and also require a stronger On Board Diagnostics system. The exhaust gas test mode also requires a new World Harmonized Steady-State Cycle (WHSC) and World Harmonized Transient Cycle (WHTC). The Ministry of Environment is planning to test the exhaust gas by 2016 by directly selecting the actual large-sized vehicle that is running on the road through the mobile exhaust gas measuring device. Cummins has been leading the technology as an eco-friendly engine company by launching a zero-emission engine that meets performance and cost.
Tier 4 (Or Stage IV) for Off-highway equipment: Effective in 2015
US EPA Tier 1 and Tier 2 standards for construction machinery were introduced in 2004-2005, and Tier 3 has been in force since 2009. However, Korea, which has participated in global harmonization activities through the Korea-EU FTA and WP29 activities, has adopted the regulations based on UN ECE R96 since 2015. Since January 1, 2015, Tier 4 Final has been in force, which is the threshold for construction equipment. The target equipment is total 30 types. 24 is new and 6 has been applied previous emission regulation, Tier 3 which is effective since 2009. The new Korea regulation is similar level with US and Europe.
Cummins Advanced technology beyond standards, Optimum emission solution
Cummins EcoFit (aftertreatment device)
Euro 6 is a strong emissions gas regulatory standard that should reduce particulate matter by 50% and nitrogen oxide by 80% compared with Euro 5. Tier 4 Final is said to be the most stringent among industrial engine emissions regulations. Cummins' cutting-edge emissions solution technology is designed to meet these demanding emission standards while enabling the engine to perform at peak performance.
Diesel engines have strong power and excellent fuel economy, but they have the drawback of emitting harmful emissions compared with other fuels. Cummins uses both natural regeneration and active regeneration to provide the best exhaust gas solutions for the engine type. The EcoFit series is an efficient exhaust gas solution that organically integrates key subsystems from filtration and diesel exhaust fluid (DEF), electronic control systems, combustion technology, fuel systems, turbochargers and aftertreatment systems. EcoFit DOC (Diesel Oxidation Catalyst) for diesel oxidation catalytic devices, EcoFit DPF (Diesel Particulate Filter) system for reducing fine dust, EcoFit Selective Catalytic Reduction (SCR) system for reducing nitrogen oxide, Eco-Ultra Low-emission systems, and the like, are optimized to handle exhaust gases efficiently and maximize efficiency.
In order to meet the high barrier emission regulations such as Tier 4 Final, a post-treatment device that reduces soot is necessary. By burning the harmful substances contained in the exhaust gas through post-treatment, the fuel consumption rate and the CO2 emissions amount can be minimized. Typical examples of this are Selective Catalytic Reduction (SCR), Diesel Oxidation Catalyst (DOC) and soot filtration (DPF) devices. The SCR exhaust aftertreatment system doses a urea solution into the exhaust stream to reduce oxides of nitrogen (NOx) emissions. In order to efficiently perform the chemical reaction when injecting the urea solution, the engine ECM senses the injection state, the tank level, and the tank temperature, and injects the mixture through the supply module and the injection module through the injection system. The urea solution exposed to the high temperature exhaust gas produces ammonia and water vapor through pyrolysis, and the ammonia reacts in the exhaust gas with the nitrogen oxide and the SCR device in the exhaust pipe to reduce the nitrogen oxide into nitrogen and water.
The regeneration process through DOC and DPF is divided into two types: passive regeneration method and active regeneration method. First, passive regeneration refers to the natural progression of exhaust gas temperature generated by normal engine operation. Active regeneration means that the temperature of the DPF is increased by injecting fuel separately. The Cummins engine employs both the passive regeneration and active regeneration methods, and determines the regeneration mode, timing, and time in the ECM according to conditions such as soot filling ratio, DPF temperature, and pressure.
More than standard technology, Cummins filtration
There are two core Cummins technologies that assist in meeting exhaust emissions standards: 'Direct Flow' and 'Crankcase Ventilation System'. Given the product features, the key to filter technology is how clean, effectively and long-lasting it can remove foreign substances. In fact, the replacement cycle time of the Cummins filters for the Tier 4 Final engine increased by an average of 200% compared with Tier 3, and the filtration capacity increased by 78% compared to the previous product.
Direct Flow (DF)
A typical air filter has a cylindrical structure. However, Cummins Direct Flow has the structural characteristic that the air flows in a straight line by designing the structure of the air filter as a V-block shape. This minimizes airflow resistance and effectively reduces energy consumption in the air cleaner system when the engine is running. It also shows excellent efficiency in the ability to remove foreign matters, which is the fundamental role of the filter, while maintaining high performance of 99.9% or more until the filter reaches the end of its life. Cummins' Direct Flow design, while boasting high performance, extends the filter replacement cycle to increase equipment uptime and reduce the cost of maintenance. In fact, the filter replacement cycle for Tier 4 Final equipment increased by an average of 200% over the Tier 3 equipment. Cummins Direct Flow is also very efficient in terms of structure. Various sensors required for the engine control unit (ECU), that is, the air flow sensor (MAF) for measuring the flow of air, the indicator for recognizing the replacement time of the filter, and the sensors capable of measuring up to temperature, can be easily assembled . In addition, it can be easily applied to engines manufactured by Cummins as well as other engines, offering a wide range of compatibility. In addition, a three-dimensional flat structure is designed to maximize the filtration area of the filter while simplifying the structure of the air cleaner housing, thereby creating an efficient engine space. Together with over five million hours of field and laboratory testing, Cummins' Direct Flow system is an optimal solution to meet Tier 4 Final emissions regulations.
Crankcase Ventilation System
The second core technology is the coalescer filter applied to the Crankcase Ventilation System. When the engine compresses the fuel in the combustion chamber, a small amount of gas leaks into the gap between the piston and the cylinder. This is called blow-by gas and crankcase emission. This gas contains a small amount of oil components, fuel residues, soot particles, hydrocarbons, and carbon monoxide. Therefore, these pollutants must be separated and filtered, and the gas must be recycled into the combustion chamber along the intake path. The Crankcase Ventilation System is a device that helps recirculate oil particles by separating the oil particles before recycling the engine's blowby gas and is a must to meet the enhanced Tier 4 Final emissions regulations.
Cummins is applying a state-of-the-art core filter in this Crankcase Ventilation System. The initial crankcase ventilation system separated the oil particles by mechanical or physical phenomenon through cyclone and impactor. On the other hand, the core-less filter can more easily and effectively separate the oil by allowing the blowby gas to pass through the medium and collecting the oil particles contained in the gas. The ability to separate oil particles through a core-less filter is nearly 95% efficient.
Cummins' technology, which has been accumulated over a long period of time, begins with the most fundamental and core efforts. This has resulted in a solution that maximizes engine performance and fuel economy, increases durability, and meets stringent international emissions standards such as the Tier 4 Final. Cummins is always ahead of the world with its unique technology and uncompromising quality.