The advancement of modern injection systems of diesel engines is related to a constant increase in the injection pressures generated by injection pumps. This translates into an improvement of the engine operation indexes, including the emission-related ones. Such an approach brings a series of problems related to the design, construction and durability of the injection system. Therefore, the authors asked whether the current market trend in injection systems is the only appropriate path to be taken. When searching for the answer, the authors decided to propose an innovative concept consisting of dissolving exhaust gas in diesel fuel with the use of an injection pump. Such a saturated solution, when flowing out of the injection nozzle, begins the process of releasing the gas dissolved in the fuel. This has a positive impact on the atomization process, hence the process of combustion. The aim of this paper stems from the previously performed research. Due to the nature of the phenomenon, it was necessary to propose a new design for the injection pump. For correct selection of the dimensions of the pumping section, it was of key importance to determine the coefficient of solubility and the bulk modulus of the solution of diesel fuel and exhaust gas. Aside from the description of the applied method and the results of the direct measurements, this paper presents the yet undescribed results of the measurements of the coefficient of solubility of different concentrations of exhaust gas in diesel fuel. The authors also investigated the influence of the amount of exhaust gas dissolved in the fuel on the bulk modulus of the solution. The final part of the paper is a description of a proprietary design of a hypocycloidal injection pump. The application of the innovative drive allows a correct dissolution of exhaust gas in the fuel.

The article presents a concept of improving operation of the engine with the effect of gas desorption from a solution with nucleation of gas bubbles. This concept consists in dissolving gas in diesel fuel until the solution is in equilibrium. At a later stage, the phenomenon is reversed, and the gas is released from the solution during its injection into the combustion chamber. The purpose of the study is to present the idea of the desorption effect along with a thermodynamic analysis of the process and to study its impact on the operation of a diesel engine. The article also describes the most important features of the injection pump adapted to employ the desorption effect, which is a proprietary, patented solution. The conducted engine preliminary tests concerned the most important parameters of the engine’s operation (indicated pressure course, pressure growth rate, heat release rate, etc.) and the emission of harmful compounds (PM—particulate matter, CO, HC, and NO_x—nitrogen oxides). A significant reduction of PM, CO, and HC, with a simultaneous increase in NO_x emissions obtained in tests, confirmed that the desorption effect facilitated engine operation.

This article presents the possibility of improving combustion using the effect of releasing hydrogen from a solution with nucleation of gas bubbles. This concept consists in dissolving hydrogen in diesel fuel until the equilibrium state of the solution is reached. At a later stage, the phenomenon is reversed, and this gas is released from the solution during its injection into the combustion chamber with a strong swirl. A characteristic feature of the solution is that when lowering the pressure (opening the atomizers), there is a decrease in the equilibrium thermodynamic potential, which results in the excess, dissolved hydrogen being released spontaneously, and this process is of a volumetric nature. This article is a continuation of the work carried out at Poznan University of Technology on the development of this concept. This article presents the results of tests for the impact of hydrogen dissolved in diesel fuel on the combustion process within a turbulent-flow environment. The tests were conducted in the combustion chamber of an engine equipped with a toroidal combustion chamber and direct injection. During the tests, the following factors were measured: the main indicators of motor operation, emission of hydrocarbons, carbon monoxide, nitrogen oxides, and particulate matters.

The paper presents the results of emission research city buses fueled by compressed natural gas and diesel. The exhaust emission tests were performed under actual traffic conditions on a regular bus line. For the measurement was used a mobile exhaust analyzer for the group of PEMS - SEMTECH DS by Sensors Inc. Based on the obtained of the result the test determined the impact of applied compressed natural gas to reduce exhaust emissions for a vehicle fueled by diesel.

The article presents the results of emission tests and vehicle operation indicators fueled with diesel oil. The tests were carried out for a passenger vehicle equipped with a diesel engine meeting Euro 3 emissions standard, moving in urban traffic. The measurements were carried out using modern PEMS (Portable Emission Measurement System) enabling the emission of gaseous components from exhaust systems of the tested object. On the basis of the conducted tests, the load characteristics were determined using the torque values obtained along with the engine speeds. The measurement route included two cycles: urban driving and fast acceleration. The aim of the study was to assess the impact of modifications to the control maps on CO, CO2, PM and NOx exhaust gas emissions under real operating conditions.

The development of compression ignition combustion engines is focused on meeting many challenges, mainly related to growing ecological requirements. Currently, however, due to technological barriers, meeting them is very difficult and requires the use of additional exhaust gas treatment systems. The use of injection of a diesel and gas solution seems to be very promising. The article presents the results of engine tests involving the use of a solution of diesel fuel and dimethyl ether. The tests were performed on a single-cylinder research engine equipped with a common rail fuel system. The obtained results suggest that the use of the solution has a positive effect on the process of creating the fuel-air mixture, resulting in a reduction in the concentration of HC and CO, while increasing the share of NOx, suggesting an improvement in the combustion process, as evidenced by the limiting injection dose.