Understanding Exhaust Gas Recirculation in Diesel Engines

EGR technology effectively reduces NOx emissions in diesel engines, ensuring compliance with MARPOL regulations.

### Understanding EGR: A Key Component in Reducing NOx Emissions in Marine Engines
* 🚢 EGR, or Exhaust Gas Recirculation, is a vital method to **significantly lower NOx emissions** in diesel engines to comply with **MARPOL NOx Tier 3 regulations**, applicable in **NOx emission control areas (NECA)**.
* 💨 The EGR process involves **redirecting 30 to 40 percent of exhaust gas** after it has been cleaned and cooled, which helps replace some oxygen in the scavenging air with **CO2**, ultimately **reducing combustion temperatures and NOx formation**.
* 🔄 The operation of the EGR system begins with **opening the utility valve for NOx and freshwater**, followed by pressing the **start button to initiate various water supply processes** and ensure proper functioning.
* 💧 During operation, treated water circulates to **neutralize acidic byproducts**, while a series of valves control the flow of seawater and processed water to **maintain optimal conditions** within the system.
* 🌊 The EGR unit features components like the **HR blower**, which pushes EGR gas to mix with normal scavenging air, and the **frequency converter** that regulates the blower speed to ensure **compliance with NOx Tier 3 emission levels**.
* 📊 The system automatically starts when engine load reaches **15** and stops when it drops below **12**, adapting to the operational needs during maneuvering.
* 🔧 Key parts of the EGR system include the **cylinder bypass valve**, **EGR blower**, and **water mist catcher**, all of which work together to facilitate **effective gas cleaning and emission reduction**.
* 📅 Stay tuned for the next video, which will cover the **HR water treatment system**, a crucial aspect of maintaining the **EGR's efficiency and compliance**.

Welcome back to Marine Real Talk. Today, I'll be sharing about the EGR, or the Exhaust Gas Recirculation. EGR is a method to significantly reduce the formation of NOx in diesel engines to meet the MARPOL NOx Tier 3 regulation that limits the main air pollutants contained in ships' exhaust gas. NOx Tier 3 emission standards are applicable only in NECA or NOx emission control areas. So, let's begin with the principle of EGR. A part of exhaust gas, after a cleaning and cooling process, is redirected to the scavenging air receiver. About 30 to 40 percent of exhaust gas is being cooled, cleaned, and recirculated. The effect of this is that a part of the oxygen in the scavenging air is replaced by CO2 from the combustion. The heat capacity of this scavenging air is hereby slightly increased, enhancing the temperature peak of the combustion, which is reduced. The queries peak temperatures reduce the formation of NOx. Each are by Mitsui Man has two types, but the application depends on the

engine board size [Music] but on this video I'll be sharing the bypass matching to give you an overview. Here's the unit of EGR on the Indian side showing the parts of EGR. So this is the EGR operation starting sequence. Before starting the EGR, open the utility valve for NOx and freshwater to start the operation. Touch or press the type 3 button in the MOB. Upon pressing the start button, the HDR water initiation will be started. The mixing chamber drain valve position is changed to the receiving tank side, followed by fresh water supply bulb to fill up the buffer tank. The MCD will lead the process water to the receiving tank during each year operation in build strength when EGR is not running. The next to open is the seawater supply valve for pre-spray, immediately followed by starting the treated water supply pump. The EJA pre-spray washes the excess gas with circulated fresh water in addition with an OAX. The NOH neutralizes fluoric acid that is formed in the processed water.

from the socks in the excess gas, the process water circulation pump running immediately followed by opening a process water sealing bulb. The process water circulating pump maintains the circulation of processed water from the receiving tank unit to the EGR unit. The buffer tank level seats will be activated at this time. The receiving tuck level bulb open then will start the pitch control until meeting the set point of about 6.5 ppm. The NOH pump start to dose NO edge solution to control the pH value then we'll start the water treatment system. On my next video, I'll be sharing the principle and operation of the water treatment system. When the age approaches, water system are started then the excess gas so the circulation will start via the HDR blower followed by the opening of shadow bulb or SOV. The SOB also ensures no backflow of scavenging air into excess gas receiver grower throttle bulb or BTB will be open. The BTB only opens when the desired pressure drop over BTB is reached. EGR now is running so I'll show

you the gas flow. Excess gas is washed in prequel during pre-spray. At the same time, the sulfuric acid from the socks is neutralized after passing to the aegean free spray. The mix of cold excess gas, steam, and precious water are lead to the egi cooler. Then, water evaporated in the each april sprays condensed in the egr cooler. The each air cooler cools down the atria gas approximately scavenging air temperature and then will pass through the water miss catcher to separate the prices water to the egr gas before the egr blower. The hr blower pushes the egr gas to the mixing chamber for mixing with normal scavenging air cooler air flow. The hr blower speed is controlled by a frequency converter acting on the egr blower motor. The amount of gas we circulated is controlled by the each air blower and the vtb so that the measured oxygen level in the scavenging air receiver matches the level corresponding to nox tier 3 emission.

the cylinder bypass bulb or CVB is open except at low load to increase the scavenging air pressure. The condensed water from miss catcher cold processed water flows to process water receiving tank and again recirculated. So let's see the starting sequence and the ERCs mop press the 3rd tree. Upon touching the start button, the H2L will automatically start. During starting time, you can see the display. The valve operation is really so fast. Yes, grill is so fast. The process water tank level should reach the setpoint first. When the process water starts to circulate, the water level in the tank will goes down and keep the receiving tank level while close. So as you can see, the water level is going down and also the bulb operation is really so fast. So with the tank level is reaching about 50 percent, then the receiving tank level bulb start to actuate. The primary purpose of this technology is to reduce the knocks but through the excess gas cleaning. Even the socks is rigorous operation at low load is clearly defined in the technical file for the

verification for nox emission at auto mode. Upon reaching the 15 engine load, the EGR will automatically start, and when engine load goes down to 12 and lower, the EGR will automatically stop. This operation is normal during the maneuvering time, wherein the main engine is frequently starting and stopping. I'll be showing the actual parts of the EGR, the cylinder bypass valve or the CBV, then here's the free spray and the each air cooler and water mist cutter. On the upper side is the cooler, and the lower side is the mist culture. On the upper portion, you can also see the each air cooler spray nozzle, followed by the EGR blower, wherein just like what I've said, the each air blower is controlled by a frequency converter. Here's the frequency converter. This is an overview of the each air blower in the mist culture. Down below is the line going to the mixing chamber, passing through the BTB or the lower throttle bulb. So here's the line going to the mixing chopper.

and to air cooler. On the other side is the process water receiving tank unit and the buffer tank. And the last one is the NaOH star. Again, thank you for watching Marine Real Talk. If you like my video, please don't forget to hit the subscribe button down below so you will be updated with my upcoming videos. On my next video, I'll be sharing the HR water treatment system. So, see you then. All right, you

EGR - Exhaust Gas Recirculation principle /Chief Boyet / Seaman Vlog/Marine Real Talk

Chief Boyet

Understanding Exhaust Gas Recirculation (EGR) in Diesel Engines

EGR is a method used to reduce NOx emissions in diesel engines, helping to meet MARPOL's Tier 3 regulation in NOx emission control areas.

The process involves recirculating 30 to 40 percent of the exhaust gas after cooling and cleaning, which replaces some oxygen in the scavenging air with CO2 and enhances the combustion temperature peak.

The EGR operation starts with opening utility valves and sequentially activating various components to initiate the process and neutralize excess gases.

Process Water Circulation and Gas Treatment System

The process water circulation pump maintains the flow of processed water from the receiving tank to the EGR unit, while the buffer tank level seats are activated.

The NOH pump doses the NO edge solution to control pH, and the water treatment system is initiated.

The excess gas is washed, cooled, and mixed with scavenging air, while the HR blower controls gas circulation to meet NOx Tier 3 emission levels.

The Cylinder Bypass Bulb (CVB) is open at low load to increase scavenging air pressure, while condensed water is recirculated between the miss catcher and process water receiving tank.

The starting sequence involves the H2L automatically starting, with the process water tank level dropping and the receiving tank level bulb actuating as the water circulates.

The EGR system operates by starting at 15% engine load and stopping at 12% or lower, with the EGR blower controlled by a frequency converter.

Overview of Marine Real Talk's Water Treatment System

The video discusses the layout of a water treatment system, including the air cooler, process water receiving tank unit, buffer tank, and NaOH storage.

The host encourages viewers to subscribe for updates on upcoming videos.

The next video will focus on the HR water treatment system.