High efficient natural gas engine concepts for long haul transportation

Different natural gas engine technologies can be applied for commercial vehicles and those investigated in the HDGAS project are: - Positive ignition natural gas engine with direct injection - Dual fuel natural gas engine (premixed gas and pilot diesel injection) - High pressure gas injection with pilot diesel injection This paper will describe the challenges and solutions of the different engine concepts in combination with LNG tank systems in respect of - Greenhouse gas reduction potential including measures to improve gas engine efficiency - Emission compliance to EU V

Результаты исследования процесса сгорания газового двигателя 6Ч13/14 с высокоэнергетической системой зажигания

The results of investigation of combustion process of natural gas engine 6CH13/14 with high-energy ignition system are given. The method of calculation of combustion process of gas engine using variable exponent of combustion m is developed

Nitric oxide conversion in a spark-ignited natural gas engine

A large percentage of stationary engine applications are natural gas fueled. The cleanest of these large bore engines currently produce on the order of one gram of NOx per brake-horsepower hour (g/bhp-hr) of work done. The goal of this work is to reduce these emissions to 0.1 g/bhp-hr levels. Selective NOx Recirculation (SNR) is a technology which will help achieve these 0.1 g/bhp-hr levels. SNR has been proven in gasoline and diesel engines, with up to 90% NOx conversion rates being achieved, but not much is known about its overall efficiencies when used with natural gas engines. This technique involves adsorbing NOx from an exhaust stream, then selectively desorbing the NOx into a concentrated NOx stream, which is fed back into the engine, thereby converting a percentage of the concentrated NOx into harmless gases. Understanding the NO conversion process plays a major role in optimizing the SNR technology. The NO conversion process was modeled using CHEMKIN, a chemical kinetic solver. The results showed decreasing the air-fuel ratio of the engine to slightly rich operation and adding EGR could increase the experimentally measured NO conversion of approximately 20% up to 90%

CAR WITH LIQUEFIED NATURAL GAS ENGINE

katedra: KSD; přílohy: 10 výkresů, 1 CD ROM; rozsah: 49 s. , 6 s. obr. přílohCílem diplomové práce je zpracovat projekt přestavby osobního automobilu Škoda na pohon LNG. Práce je zaměřena především na návrh plynové palivové instalace a to včetně zástavby kryogenní nádrže a dále potřebné úpravy motoru. V závěru diplomové práce jsou stanoveny očekávané provozní parametry automobilu s tímto pohonem.An objective of my diploma thesis is to compile a conversion project of a car SKODA to LNG fuel. Effort is focused above all on design of a gas fuel system installation include mounting of a cryogenic tank and also on needed modifications of the engine. In the end of diploma thesis are determined expected functional car parameters with this fuel system

Hydrogen Addition For Improved Lean Burn Capability of Slow and Fast Burning Natural Gas Combustion Chambers

One way to extend the lean-burn limit of a natural gas engine is by addition of hydrogen to the primary fuel. This paper presents measurements made on a one-cylinder, 1.6- liter natural gas engine. Two combustion chambers, one slow and one fast burning, were tested with various amounts of hydrogen (0, 5, 10 and 15%-vol) added to natural gas. Three operating points were investigated for each combustion chamber and each hydrogen content level; idle, part load (5 bar IMEP) and 13 bar IMEP (simulated turbocharging). Air/fuel ratio was varied between stoichiometric and the lean limit. For each operating point, a range of ignition timings were tested to find maximum brake torque (MBT) and/or knock. Heat-release rate calculations were made in order to assess the influence of hydrogen addition on burn rate. Addition of hydrogen showed an increase in burn rate for both combustion chambers, resulting in more stable combustion close to the lean limit. This effect was most pronounced for lean operation with the slow combustion chamber

Reduction of natural gas engine emissions using a novel aftertreatment system

The global objective of this study was to develop an exhaust aftertreatment system to reduce gaseous and particulate matter emissions from natural gas fueled vehicles. Specific objectives of this study were to evaluate and characterize emissions from a natural gas fueled vehicle powered by a Cummins C8.3G+ engine with and without the particulate matter (PM) filter and oxidation catalyst (OC) combination, which was designed and developed by West Virginia University in collaboration with Lubrizol-ECS. Central Business District (CBD) Cycle tests were performed on West Virginia University\u27s Transportable Emissions Testing Laboratory. A heavy-duty transportable chassis dynamometer and a dedicated clean dilution tunnel were used to sample emissions from the vehicle. Past studies indicate that the use of a clean dilution tunnel omits the possibility of background emission concentrations being higher than actual vehicle-out emissions. Therefore, a clean primary dilution tunnel was designed, fabricated, and implemented for use during this study to avoid contamination from tunnel history. (Abstract shortened by UMI.)

Study of sequential multipoint injection nozzle effect of compressed natural gas engine

The research and development of injection system has always been influenced by the availability and the form of fuel. In this project is about the study of the injection nozzle effect of compressed natural gas engine. This project study and simulate twenty types of sequential injection nozzle with different geometries using SolidWork and Cosmos FloWork software to find the best air and fuel mixing in the combustion chamber of the engine. The other effect of the modified injection nozzle is the velocities of the fuel in combustion chamber that can be determine using the software. The length of bore and stroke of the engine is base on the actual diesel engine and been model using SolidWork. As the result, the best injection nozzle is 10 degree nozzle. The air and fuel mixing is very good and better compare with the original injection nozzle. The velocity of fuel in combustion chamber is the highest compare with other design

Control-oriented modeling, validation, and analysis of a natural gas engine architecture

In order to improve performance and meet increasingly tight emissions regulations, engine manufacturers must improve algorithms used to control the engine. One possible strategy is to utilize centralized control algorithms that take into account the coupled interactions between inputs and outputs. Implementing a centralized control strategy often requires some kind of dynamic model of the system, which is a primary motivation for modeling efforts in this thesis. In a methodical fashion, this thesis derives a control model for a natural gas engine architecture and validates this control model against reference data in simulation. Additionally, this thesis performs control-oriented analysis on a state-space model provided by Caterpillar to determine the engine’s suitability to decentralized control. Based on the results of the control-oriented analysis, the thesis demonstrates how a decentralized control framework can be implemented. The first study declares a set of seven state variables that characterize the operation of the engine. The engine of interest runs on natural gas and is used in power generation applications. Additionally, this study models all mass flow rates and power terms as functions of the selected state variables. These models are then validated against truth-reference data. This study also explicitly states the assumptions and simplifications that correspond to each of the models. The second study derives dynamic equations for each of the seven state variables via a first-principles approach. The dynamic state equations contain expressions for mass flow rates and power that were modeled in the first study. This study then numerically validates the entire state-space model by exercising control inputs from reference data on it. Together, the seven state equations effectively serve as a control model that can be used for controller synthesis. The goal of the first two studies is to demonstrate a procedure for obtaining a control model for an engine architecture, not to obtain a high-fidelity simulation model. The third study demonstrates control-oriented analysis on a state-space model provided by Caterpillar. The relative gain array (RGA) is used to show that the system is well-suited is for decentralized control. This study implements a decentralized control structure on the state-space model provided by Caterpillar and validates, in simulation, its ability to achieve reference tracking for desired outputs

Installation and testing of a Cummins QSK19 lean burn natural gas engine

2013 Spring.Includes bibliographical references.The goal for a more efficient engine will never disappear. Over the years many different techniques have been explored within the common goal of higher efficiency. Lean combustion has proven to be effective at increasing efficiencies as well as reducing emissions. The purpose of this thesis is to install a modern Cummins QSK19G and perform certain test that will explore the lean combustion limits and other methods that could possibly increase efficiency even more. The entire installation and instrumentation process is documented within this thesis. The engine was installed in the Engines and Energy Conversion Laboratory at Colorado State University. The engine was installed with the hopes of instilling the desire for endless future tests from Cummins as well as other companies seeking this type of research engine. The lean limit was explored in the most detail. Cummins supplied a test plan that satisfied their desired stopping at a lean limit when the coefficient of variance of indicated mean effective pressure reached 5%. For the curiosity of others involved and this thesis, the lean limit was explored further until the engine could no longer ignite the ultra-lean combustion mixture. Friction accounts for a significant loss in a modern internal combustion engine. One role of the engine oil is to reduce these frictional losses as much as possible without causing increased wear. A test was conducted on the QSK19G to explore the effects of varying the engine oil viscosity. Frictional losses of two different viscosity oils were compared to the stock engine oil losses. The fact that reducing oil viscosity reduces frictional losses was proven in the test