ArenaRed

Smart Combustion Technology

Combustion Diagnostics

Less downtime and optimized combustion process is achieved by monitoring the combustion diagnostics. Several engine hazards are explained on this page that are monitored by the CPBC. The figure below shows an example of a pressure trace given by a CPS during one combustion cycle that the CPBC uses to extract the combustion diagnostics from.


Knock

Knock occurs when the air/gas mixture auto-ignites. The combustion process with engine knock develops much faster and with more violence than an ordinary combustion process, and gives a distinctive knocking sound. Knocking can cause severe damage to the engine. The rapid combustion process results in enormous pressure oscillations with high pressure peaks that induces more heat into the piston, valve and head, which will eventually fail.

The Combustion Pressure Based Control (CPBC) realized by the ArenaRed CPBC chip and the ArenaRed Combustion Pressure Sensor (CPS) detects knock in an early stage and eliminates knock per cylinder every power stroke.

 

Blowby

Blowby is a leak between piston and sleeve creating a weld between piston and sleeve, which is explained in the next section. Blowby can cause a total loss of the engine within 1 second. ArenaRed CPBC monitors blowby and when it is detected the fuel feed is cut off to that particular cylinder in order to prevent the total loss. A message is send to the helm and/or the fleet maintenance service in order to plan maintenance and change that particular piston and sleeve. 

When a significant leak between piston and cylinder arises, the burning mixture starts flowing between piston and sleeve, the heat of this spray is similar to a cutting torch. The blowby will create a growing iron melt and as soon as the melt is big enough in terms that the blowby is incapable to maintain the melt, the melt will solidify. At that moment the piston is welded to the sleeve. This welding takes place within 1 stroke. When a four-stroke engine runs 1200 rpm there are 10 combustion cycles per second. In the event of blowby some pressure loss in the compression stroke will be detected, if so the fuel supply will be stopped instantly and can be fixed in a planned service without the loss of performance.

Thanks to blowby detection and CPBC in general, insurance companies see a chance to lower its price for engines equipped with ArenaRed's CPBC.

 

Pmax

The peak combustion pressure is called the Pmax, when Pmax exceeds a certain value engine damage can occur. Exceeding Pmax will be detected by the AR CPBC and hence will be minimised by changing its injection strategy without any loss of performance. 

    

Pre-ignition

When the combustion starts earlier than planned, this is called pre-ignition. This can be caused for example by hot spots in the combustion chamber, like an edge of the piston or glowing soot deposits. Another pre-ignition source could be lubrication oil that slipped into the combustion chamber and auto-ignites. For example, in the EMD engine this is a major concern, due to the two-stroke principle of the intriguing EMD engine it has more chance of oil leaking into the combustion chamber than a four-stroke engine. The lubrication oil can auto-ignite and causes the gas charge to pre-ignite, which can lead to damageable knock. The CPBC of ArenaRed monitors these events and makes sure that the appropriate measures are taken, this could be an advice to change that piston and sleeve and meanwhile have only that cylinder run on diesel only.

  

Pressure Rise Rate (PRR)

Exceeding the rated PRR means that the pressure increase with respect to the crank angle is exceeding the engine specifications. Thermodynamically a high PRR is desirable but will also lead to excessive engine wear. The CPBC will monitor and control the PRR for obtaining an optimal efficiency with a controlled minimum amount of wear.    

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