Abstract: A method for controlling a dual fuel engine system includes estimating a total indicated engine load, where the total indicated engine load is based on a sum of a measured engine power and a power loss estimate. The method further includes determining a total fueling amount based on an engine speed and the total indicated engine load, where the total fueling amount includes a gas fueling amount and a diesel fueling amount. The method also includes controlling the dual fuel engine system using the total fueling amount.

Abstract: A method for controlling a dual fuel engine system includes determining a friction power loss amount of an internal combustion engine of the dual fuel engine system, where the friction power loss amount is based on an engine speed of the internal combustion engine and a friction torque estimate. The method also includes determining an accessory power loss amount of a power of the internal combustion engine, where the accessory power loss amount is based on the engine speed and an accessory torque estimate. The method further includes estimating a net engine power amount based on the accessory power loss amount and a brake power amount of the internal combustion engine, estimating an indicated diesel power, and estimating, based on the estimated net engine power, a first indicated engine power and a first gas power.

Abstract: A centralizer is disclosed having outwardly bowed leaf springs held by one or more circular end bands. The end bands have two or more sections which are radially overlapped and snapped together to hold the centralizer about a cylindrical object. The end bands can also include a lock to help prevent separation of the end band sections.Also disclosed is a snap-together method of assembling a centralizer including positioning a first portion of the end band partially around a cylinder, positioning a second portion of the end band partially around the cylinder so as to overlap the first portion, interlocking the portions, pressing to leave the centralizer in position. A projection of one of the portions can be pressed against the other portion to keep the portions interlocked.Further disclosed is a circular band for attachment to a cylindrical object. The circular band has two arcuate portions, one with a radial projection and the other with a hole for receiving and interlocking with the projection.