Transient modelling of a HC-SCR catalyst for diesel exhaust aftertreatment

The optimal volume of a combined system of LNT and SCR catalysts

“…(3). The intermediate product NH 3 increases due to the shortened reaction time as a result of the increase in SV on the LNT catalyst, which acts as a reductant for the SCR catalyst downstream of the combined system of LNT + SCR. the NOx storage capacity is small, and so the generated N 2 O is small.…”

“…Several technologies are being implemented in order to reduce these harmful emissions. Typical ways of reducing NOx emissions are urea-SCR, which dispenses urea as a reducing agent; lean NOx catalyst (LNC) [1], which uses hydrocarbons (HCs) as the reductant [3]; and LNT (Lean NOx Trap) [4,5]. Urea-SCR is the most effective among these techniques, and is employed mainly on heavy-duty diesel (HDD) engines [5,6].…”

Characterisation and Model Based Optimization of a Complete Diesel Engine/SCR System

“…One temperature state in each tank and one ammonia coverage in each wall layer results in a total of 18 states. This is a less dense discretization than traditionally used, for example, Westerberg et al use 10 tanks in the axial direction [26], Andersson et al [21] use 33 tanks. Devarakonda et al [27] conclude that no more than 15 tanks are necessary in the higher order model presented.…”

Balanced Truncation of Linear Time-Varying Systems

“…So, new states should just be initialized to zero. If there are continuous solutions and to the inequalities (25) and (29) we can readily use them as solutions to the discrete-time Lyapunov equations for the jump 34which are fulfilled with and . For each jump, we therefore get the following addition to Lemma 3: with and .…”