The present disclosure relates generally to aftertreatment of exhaust gases in internal combustion engines. The teachings thereof may be embodied in a method for operating a secondary air system comprising: measuring an actual pressure downstream of a pump of the secondary air system; acquiring a dynamic pressure based on the actual pressure, characteristic of changes caused by dynamic operation of the engine; acquiring a basic pressure based on peripheral conditions of the secondary air system; calculating a model pressure based on the basic and the dynamic pressure; determining a capacity of the pump based on a ratio between the model pressure and the actual pressure; and adjusting operation of the secondary air system based on the capacity.

A thermal management system for an aftertreatment system includes an air pump and a compressed air rail. The compressed air rail is fluidly connected with the air pump. The thermal management system further includes a first valve located between the compressed air rail and an exhaust outlet pathway. The first valve is configured to selective supply air to the aftertreatment system of the engine. The thermal management system further includes a heater located between the compressed air rail and the first valve. The heater is configured to heat the air before supplying air to the aftertreatment system of the engine.

In accordance with example implementations, a vehicle includes a body, an engine within the body, and at least one exhaust tube extending from the engine and having a particulate filter fluidly coupled to the exhaust tube to receive exhaust material from the exhaust tube. The vehicle also has at least one air injection pipe having a first end with an inlet arranged to receive air flow entering the body while the vehicle is moving, wherein the air injection pipe comprises a second end fluidly coupled to the exhaust tube and having an outlet positioned to provide air flow from the injection pipe into the exhaust tube upstream from the particulate filter. Passive soot regeneration with THC and CO reductions is realized by this introduced air flow.

A method and a device for diagnosing an air supply of an internal combustion engine which includes a first air duct for supplying air to a cylinder and a second air duct for supplying air to a heater for heating an exhaust system. The first and second airs ducts each have a mass flow sensor for measuring a mass of the air flowing therethrough, a pressure sensor for measuring the pressure in the air duct, and a temperature sensor for measuring the temperature of the air flowing therethrough. The first and second air ducts originate from a common air filter. Depending on operating states of the cylinders and heater, measured values of the mass flow sensors, pressure sensors, and temperature sensors of the first and second ducts are compared with one another or with comparison values, and a result of the diagnosis is ascertained depending on the comparison.

An exhaust purification device includes: a filter including an oxygen storage capacity (OSC) material; a secondary air supply passage connected to the exhaust passage upstream of the filter; a secondary air control valve disposed in the secondary air supply passage and configured to provide periodicity to secondary air supplied to the secondary air supply passage; and an engine control unit (ECU), wherein the ECU controls the secondary air control valve so as to supply the secondary air with a predetermined frequency and a maximum amplitude of an oxygen concentration. The secondary air control valve is controlled so that when the frequency of the secondary air is fixed to a value of greater than 0 Hz and less than or equal to 1.5 Hz, the maximum amplitude of the oxygen concentration is greater than 0.50% and less than or equal to 3.0%.

A method for controlling a secondary air mass flow in a secondary air supply of an internal combustion engine. The internal combustion engine comprises the secondary air supply, a device for determining a pressure in the secondary air supply, and an exhaust gas lambda sensor for determining a current exhaust gas lambda value. The method includes a) determining a first secondary air mass flow) related to the effective throttle area using a throttle equation and depending on a pressure in the secondary air supply, b) determining a second secondary air mass flow based on the measured exhaust gas lambda value and taking into account a primary air mass flow of the internal combustion engine and a supplied fuel mass flow, c) deriving an effective throttle area from the first secondary air mass flow determined in step a) and the second secondary air mass flow determined in step b), and d) controlling the secondary air mass flow in the secondary air supply using the effective throttle area determined in step c) or a quantity derived therefrom.