Method for determining pressure between reciprocating pump and metering valve of selective catalytic reduction (SCR) catalyst system, involves determining the pressure from the course of pump current of the reciprocating pump

摘要

The pressure between the reciprocating pump and the metering valve of the selective catalytic reduction (SCR) catalyst system is determined from the course of pump current (I) of the reciprocating pump. The pressure of a period (tMSP) is determined between the timing (t0) and timing (t1). The reciprocating pump is energized by a change of the pump current to an energized state. The pressure is calculated by multiplying the period with a slope factor and the supply voltage of the reciprocating pump and adding an offset to the resulting product. Independent claims are included for the following: (1) a computer program for determining pressure between reciprocating pump and metering valve of SCR catalyst system; and (2) a computer program product for determining pressure between reciprocating pump and metering valve of SCR catalyst system.