What is EGR and SCR on a ship? Troubleshooting and Fault Finding

Modern marine diesel engines operate under strict environmental regulations established by the International Maritime Organization (IMO), particularly Tier II and Tier III NOx limits. To comply with these standards, ship engines are equipped with exhaust gas emission control systems.

The two main technologies used onboard are:

• EGR (Exhaust Gas Recirculation)
• SCR (Selective Catalytic Reduction)

Both systems are designed to reduce nitrogen oxides (NOx), but they work in fundamentally different ways.

As an example, the article considers the MITSUI-MAN B&W 6S50ME-C9.5-EGRBP main engine with an EGR system and auxiliary Daihatsu 6DE-18 Tier III 630kW engines with an SCR system.

MAN ME Electronic Main Engine. Troubleshooting

Greetings! In this article, I introduce the MAN ME electronic main engine, the general concept of MAN ME engines, and examine its individual components — FIVA, ELVA, ELFI, Alfa Lubricator, and Tacho Pickup — as key systems for troubleshooting. As an example, the article examines the MITSUI-MAN B&W 6S50ME-C9.5-EGRBP main engine with an EGR system.

Modern two-stroke, low-speed engines from the ME series by MAN Energy Solutions are fully electronically controlled engines. Unlike mechanical systems, fuel injection, exhaust valves, and cylinder lubrication are controlled by electronic control units via hydraulic actuators.

This article summarizes key information on the main engine systems and troubleshooting algorithms.

Main Engine Protections. Quick Check for Inspectors

Greetings! In this article, I recommend that you familiarize yourself with the main protections of the main engine on a vessel, which are most often checked by inspectors. The main engine and its auxiliary systems have a lot of protections, so only the main ones will be described, which are demonstrated when passing a particular check.

The main engine and auxiliary engines differ mainly in their purpose. But in terms of protection, they have much in common. In the article "Diesel Generator Protections. A Quick Check for the Inspector" oil mist detectors (OMD - Oil Mist Detector) were mentioned, which can be installed on diesel engines with a capacity of 500 - 1000 kW, so on the main engines, as a rule, they are.

Checking protections of the main air compressors

Greetings! I continue to write articles on checking the protection of various mechanisms on a ship and this time we will consider the compressors of the starting air of the main engine. Usually, they are of no interest to inspectors, but there are exceptions.

In this article, we will consider the main protections of the main air compressors that directly concern electricians. Let's take Japanese TANABE compressors as an example.

How to read electrical diagrams on a ship? Main engine turning gear operation diagram

Greetings! You have motivated me to write this article. Thank you for your comments to the previous article "Installing a timer in the electrical diagram of the main engine turning gear" and in social network groups. In fact, writing such articles takes a lot of time and effort, so motivation and support are needed. And it is enough to just write a positive review ;)

In this article I will try to explain in simple language the principle of reading electrical circuits on a ship using the example of the main engine turning gear device.

Main engine protection failure. Troubleshooting

Greetings! Today we have a problem with the main engine, all protections have failed, an alarm has appeared on the BMS-2000III panel - “EPS Power Failure”. In this article we will figure out what this alarm is and how to fix this problem.

First of all, you need to understand what “EPS Power Failure” means, for this we refer to the instructions. EPS is the Engine Protecting System for the main engine. The power supply for this system has failed.

The main engine does not start. Troubleshooting

Greetings! Today we have a problem with starting the main engine; the engine cannot be started with air by the telegraph command “Forward” and setting a certain speed (the telegraph and the speed controller are not one common device here).

In the article we will find out what the problem is and what you should pay attention to during routine maintenance of the main engine control unit.

Phase fail. The turning gear and the LO autofilter of the main engine do not start

Greetings! Today we have a problem with the turning gear and the LO autofilter of the main engine. During the preparation of the main engine, alarms were sent to the alarm monitoring system in the ECR indicating that some kind of problem had occurred with these mechanisms.

It is necessary to pay attention to the fact that problems with starters or motors occurred at the same time and perhaps they have something in common. On a ship, these systems are not connected to each other in any way.

UPS fail. Main engine automatic backup does not work. Kongsberg Troubleshooting

The UPS fail error occurred and the final system for protecting the main engine against automatic power failure failed. A BMS AC220V UPS FAIL alarm appeared on the alarm monitoring system in the ECR. BMS - Bridge maneuvering system.

BMS AC220V UPS FAIL

In simple words, the uninterruptible power supply (UPS), which is designed for the normal operation of the automatic control system of the main engine during the transition of the ship's electrical station from main to emergency power, has stopped working.

Installing a timer in the electrical circuit of the main engine turning gear

Greetings! With this post I propose to start the section “reading electrical diagrams on a ship” and examine one of the interesting questions regarding the shaft turning gear of the main engine.

This article is primarily suitable for those who already have some knowledge of reading electrical circuit diagrams.

Failure of the remote automatic control of the main engine. Actions of the ETO. Kongsberg Troubleshooting

Greetings! In this article, we will consider the actions of the ETO in case of failure of the remote automatic control of the main engine (real situation).

The vessel is equipped with the AutoChief C20 Propulsion Control System, which is very often used for fixed-pitch MAN MC engines. Produced by Kongsberg Maritime.

Precautions at Slow- and Shut-Downs

In the event of a slow- or shut-down occurring, the appropriate lamps light up on the bridge telegraph and in the signal panel for emergency in the control room. If, with regard to the safety of the vessel, it proves necessary to start the engine again, the "cancel" button on the bridge telegraph can be activated. Since this is an emergency function, it will immediately release an alarm in the engine room.

If it is not imperative for the engine to run, the fault should be rectified before the engine is stated again. When the fault has been rectified, the reset button is pressed on the control room.

Main Engine Control System for Internal Combustion Marine Diesel Engines

Main engine control system is used for automatic remote control and protection of main ship's diesels. It permits to change direction and speed rotation of propeller directly from the bridge by navigators. The system consists of the equipment installed on the bridge, engine control room (ECR) locally mounted near the engine.

The set of Engine Remote Control equipment in ECR essentially consists of a panel fitted up with the various signalling, alarm and control facilities, in addition to the electronic modules (both logic and analog).

Electronic Control Modules Rack comprises:
a) Engine starting and reversal logic module, with LED display (direction of rotation indicator) of logic status and starting set-point adjust potentiometer status;
b) Digital/analog engine RPM converter with cut-in thresholds and LED display of the status of the thresholds and thresholds adjusting potentiometers.
c) Engine control programmer with LED display of stand-by, RPM reduction, emergency, etc. and acceleration gradient adjusting potentiometer.
d) RPM controller with potentiometers for variables and operating limits adjustment.
e) Torque lirniter, with limit indicator.

Locally Mounted Equipment comprises electro-hydraulic type actuator, for remote control of the fuel linkages; the said actuator is continuously linked mechanically to the lever and is therefore driven by the manual handwheel when it is deenergized.

The equipment also comprises induction type pick-ups to monitor the number of RPM's and rotating direction, as well as a five-position servo-motor, complete with four devices to position the engine local control lever for reversing gears and starting air distributors for engine stop, running ahead, starting ahead, running astern, starting astern. Equipment on Bridge comprises:

1. Engine telegraph.
2. Automatic control panel. It has the following items mounted on panel front:
a) Manual power limiter.
b) Engine speed fine adjustment potentiometer.
c) Illuminated push-button for bridge control demand.
d) "Control transfer inhibited" signal display.
e) "Control on the bridge/ECR" signal display.
f) Direction of engine rotation indicator (LED).
g) Engine RPM indicator.
h) Fuel oil lever actuator position indicator.
3. Shield push-button for emergency stop and emergency manoeuvring.

What is a Shaft Generator? Automatic Control of the Shaft Generators

When the order is issued for the main engine to operate at a constant speed corresponding to the correct frequency, and if the load on the distribution network is not in excess of the maximum permissible load on the shaft generator, and if no alarm is operative on the shaft generator, this combination of conditions is indicated on the control panel by the "shaft generator ready" lamp lighting up.

The generator then rotates at the correct speed although without excitation, i. e. it generates no voltage.

If the change-over switch on the control panel is set to the "shaft generator on" position the generator will be excited and will generate a voltage. When about 85% of the normal voltage is attained, control of excitation shaft generator will be taken over by the voltage regulator in the switchgear.