The purpose of the present invention is to provide a trigeneration system using dimethyl ether (DME), wherein the system produces electricity, controls heating and cooling, and supplies carbon dioxide as a fertilizer by driving a DME engine by using, as a raw material, DME which is clean fuel. A trigeneration system using DME according to the present invention may comprise: a DME tank in which DME fuel is stored; a DME engine driven by means of the DME fuel as a raw material; a DME fuel supply unit for supplying the DME fuel stored in the DME tank to the DME engine; a treatment unit connected to an exhaust line for discharging exhaust gas from the DME engine, so as to treat harmful components of the exhaust gas; a power generation unit for producing electricity by means of a driving force of the DME engine; and a cooling and heating unit for supplying or collecting heat by means of the driving force of the DME engine.

A heavy-duty truck has a diesel engine, an exhaust after-treatment system, and an engine control unit. The exhaust after-treatment system includes a close-coupled selective catalytic reduction system and an underbody selective catalytic reduction system, a first NO.sub.x sensor upstream of the close-coupled selective catalytic reduction system, a second NO.sub.x sensor between the two selective catalytic reduction systems, and a third NO.sub.x sensor downstream of the underbody selective catalytic reduction system. The engine control unit may perform methods allowing intrusive diagnostics to be performed on exhaust gas NO.sub.x sensors using the selective catalytic reduction systems during normal operation of the heavy-duty truck.

A method for the onboard diagnosis in a vehicle having a catalytic convertor and a lambda-controlled internal combustion engine in the running operation of the vehicle, includes determining the currently maximum possible oxygen storage capacity of the catalytic convertor as well as a measured temporal duration between the lean spike of the pre-catalyst lambda probe and the post-catalyst lambda probe takes place by means of an OSC diagnosis. The method also includes determining a theoretical residual oxygen content and determining a theoretical temporal duration. When the quotient between the measured temporal duration (Δt) and the theoretical temporal duration (Δt.sub.theo) lies within a predefined range delimited by a first and a second threshold value (SW1; SW2), thus:

[00001]$\mathrm{SW}1\le \frac{\Delta t}{\Delta t_{\mathrm{theo}}}\le \mathrm{SW}2,$

it is determined that the pre-catalyst lambda probe and the post-catalyst lambda probe operate without flaw.

A method, system, and apparatus use infrared spectrometry onboard an internal combustion engine running on a natural gas fuel to detect characteristics of the fuel. At a site having a plurality of natural gas engines, detection of natural gas fuel components and concentrations of the components also is conducted at the site upstream of the point of intake of the natural gas fuel to one or more of the engines. Operating parameters of the engine or a plurality of the engines may be controlled on the basis of the detected composition of the natural gas fuel.

An air-fuel ratio control system (1) including an air-fuel ratio control section (3) for controlling the air-fuel ratio λ of an air-fuel mixture, an exhaust gas purifier (4); an air-fuel ratio sensor (5) whose output changes sharply when λ in the exhaust gas changes between rich and lean sides about a stoichiometric air-fuel ratio; a heater (6); and a temperature control section (7). The air-fuel ratio control section (3) controls λ based on the output of the air-fuel ratio sensor (5) using, as a target air-fuel ratio, a predetermined air-fuel ratio such that 0.980≤λ<1.000 is satisfied, and when a change amount Δλ λ is 0.008, an output difference ΔV is 150 mV or smaller. The temperature control section (7) controls the temperature of the air-fuel ratio sensor (5) to a predetermined target temperature of 650° C. or higher.

A system for diagnosing a misfire of an engine includes a sensing unit including at least one sensor for detecting at least one detection value associated with an operation of the engine, and an electronic control unit configured to determine whether a misfire of the engine due to exhaust valve leakage has occurred based on the detection values from the sensing unit, and perform an operation corresponding to the misfire due to exhaust valve leakage when the misfire due to exhaust valve leakage has occurred, wherein the electronic control unit a misfire code for exhaust valve leakage in a memory when the misfire due to exhaust valve leakage has occurred.

An apparatus includes circuitry configured to calculate a temperature of exhaust flowing into an exhaust after-treatment system as a first exhaust temperature, calculate a temperature of exhaust flowing out from the exhaust after-treatment system as a second exhaust temperature, calculate a rate of change over time of the first exhaust temperature and a rate of change over time of the second exhaust temperature, and judge if the exhaust after-treatment system is in a removed state removed from the exhaust passage based on a difference between the rate of change over time of the first exhaust temperature and the rate of change over time of the second exhaust temperature.

An engine system including a fuel system control arrangement includes an internal combustion engine including an exhaust line, one or more cylinders, and one or more fuel injectors corresponding to the one or more cylinders, means for determining fresh air mass flow into an intake to the engine, a nitrogen oxide (NOx) sensor in the exhaust line, and a controller configured to determine oxygen (O2) in exhaust gas based on a signal from the NOx sensor and to calculate a current fuel injection quantity based on the O2 in the exhaust gas and determined fresh air mass flow into the intake, to compare the current fuel injection quantity to a theoretical fuel injection quantity under current operating conditions, and to adjust an amount of fuel injection from the one or more fuel injectors when the current fuel injection quantity differs from the theoretical fuel injection quantity to make the current fuel injection quantity closer to the theoretical fuel injection quantity.

A fugitive gas detection system is provided. The system includes a cloud service, a plurality of reach-based components, a plurality of wireless gas sensors. The reach-based components comprise backhauls and gateways. The wireless gas sensors are acted as nodes to acquire sensor data in a local mesh network and the nodes are connected to the cloud service through the reach-based components, one node can transmit the sensor data to other sensor nodes of the local mesh network. The system measures flammable gas levels with speed, economy and accuracy.

Methods, systems and devices for evaluating incoming air to an engine, industrial controller including engine controls, valves and solenoids, for concentrations of explosive or combustible gases or vapors, and actuating process control including but not limited to shutting down an engine or other industrial process to control an outcome including the prevention of an overspeed condition when pre-set or calculated elevated gas or vapor concentrations are detected. In some embodiments industrial control including engine shutdown may be achieved conventionally via an electronic kill signal, a shutdown of the fuel injector, carburetor or fuel pump, and in emergency conditions by the shutoff of incoming air to an air intake, turbocharger, or other air delivery systems. Decisions based on explosive gas or vapor concentrations and species and the use of networking to allow additional systems to take action before explosive gases or vapors reach said other valve-sensor devices can provide additional safety.