VANE 3J0711 - Caterpillar

Thermal Management/Mitigation
Hydrocarbon (HC) Release Procedure
If your Cat Engine and Aftertreatment System are in a Level 2 or Level 3 code situation, the rig operator or technician will need to increase engine load to target a higher exhaust temperature. The HC Release Procedure will allow the engine to raise engine exhaust temperature and remove the accumulated HC from the catalyst system.For the HC Release Procedure, operating schedules are listed for two IMAT conditions for the Offshore Petroleum applications to remove hydrocarbon sufficiently from the catalyst and return to work.Note: Times of HC Release Procedure may vary due to differing IMAT or ambient conditions and rig design.To perform the HC Release Procedure to remove HC from the catalyst effectively and efficiently, follow the guidelines listed in the table below that is applicable to the engine rating.
Table 1
3516 Offshore Petroleum Engine
Load (%) 25° C (77° F) IMAT 55° C (131° F) IMAT
10 10 hours 210° C (410° F) 1.75 hours 230° C (446° F)
25 1 hour 270° C (518° F) 19 minutes 310° C (590° F)
50(1) 21 hours 305° C (581° F) 6 minutes 365° C (689° F)
(1) Load to 25% for 15 minutes, then proceed to target SCR temperature inlet temperature listed.The procedure duration will vary based on the ambient conditions, HC loading percentage, and the available engine load (%). For the operator to perform the procedure, engine speed, engine load (%), or power (kW) and SCR inlet temperature are to be displayed.Preferred Load Step
25% Engine Load for all IMAT to remove HC
Perform the following procedure:
Before increasing speed or load, ensure that all requested parameters are visible.
For the 3516 Offshore Petroleum engine, prepare the rig so that the engine can safely be loaded for the desired engine loading for the prescribed time. For example: at 25° C (77° F), prepare the rig to load the engine at 25% engine load for more than 1 hour.
Find the appropriate HC Release Procedure for your Offshore Petroleum Engine System. When ready raise the engine speed to 1200 RPM with no engine load. Then gradually apply the engine load up to the desired engine load while monitoring the SCR Inlet Temperature. Use the engine speed or load references for this step to maintain the SCR Inlet Temperature listed in the procedure continuously for the time prescribed. For example: at 25° C (77° F), target an SCR inlet temperature of 270° C (518° F).Note: The SCR Inlet Temperature may go over the targeted SCR Inlet Temperature. Adjust the engine load to keep the SCR Inlet Temperature no greater than 15° C (59° F) over the SCR Inlet Temperature target in the HC Release Procedure. If the SCR Inlet Temperature exceeds the threshold, then reduce the engine speed accordingly.
Maintain the SCR Inlet Temperature until the HC Release Procedure is complete, allowing the vessel to return back to work. SPN 2434-1 Engine Exhaust Manifold #1 Temperature #1: Low - Most Severe (3) should be inactive and logged. SPN 2434-18 Engine Exhaust Manifold #1 Temperature #1: Low