Comparative analysis of characteristics of liquid fuel combustion for various designs of oil-steam burners

The paper presents a comparative analysis of experimental data on combustion of liquid hydrocarbon fuels in the presence of superheated steam in two designs of the developed burners. By the example of diesel fuel burnt in a spray burner it is shown that lower values of nitrogen oxide contents in the exhaust gases are achieved in comparison with an evaporative burner. At that, the content of carbon monoxide in some regimes is lower for the evaporative burner. The regimes with the minimum content of toxic combustion products are found for both designs of the burners.

Theoretical and experimental analysis on environmental pollution with exhaust gases at the mechanical dislocation of rocks, located in a protected nature environment

The paper approaches the theoretical and experimental analysis of the level of exhaust gas pollution in a protected nature environmental, located in the mountain area, for excavation a trench. Due to the legislative provisions prohibiting the use of explosives in the nature reservation or other protected nature environmental areas, the mechanized excavation solution remains the only viable option. Excavation the trench through the mechanized solution must be carried out, taking into account the maximum level of pollution with exhaust gases provided in the legislative norms. According to the geotechnical data, the rock composition to be excavated on the route will be of different hardness, which involves impactors of various powers to displace the rock, on the one hand, and on the other, different excavators and bulldozers for the handling the material resulted from excavation. The theoretical research required to solve the problem has several stages, of which we mention: choosing the correct mechanization solution for displacing the hard and very hard rock; determination of fuel consumption, and energy consumption, respectively, transformation of the energy consumed in the liquid fuel necessary for the tool driving engines, and which generate exhaust gases.

Study concerning the thermal energy balance in an internal combustion engine

In this scientific report the steps for achieving the energy balance on a test engine Daewoo 1.6 liter in 4 cylinders, with 4 valves per cylinder, its power being77 kW, are presented. The engine was connected to a hydraulic brake during the tests. The energy balance was established, based on measurements applied on the stand test, focusing to determine the lost heat and to conceive a Sankey diagram, accordingly. Two sets of measurements were performed and based on them the heat losses were determined and two Sankey diagrams were depicted. The lost heat through the cooling fluid is determined by measuring the cooling water flow rate and its inlet and outlet temperature. The lost heat through the exhaust gases is determined by the difference between the enthalpy of the exhaust gases and the enthalpy of fresh air. The lost heat due to incomplete chemical combustion is determined by analyzing the composition of the exhaust gases. The measurements are centralized on a graphic user interface, supported by a NI Compact RIO platform.

HARDWARE AND SOFTWARE OF AUTOMATIC CONTROL SYSTEM OF FUEL COMBUSTION PROCESS IN LOW AND MEDIUM POWER BOILERS. PART 2. ALGORITHMIC SOFTWARE

The efficiency of the functioning of boiler units depends on the availability of reliable information on the progress of technological processes. The lack of control and measuring systems for the composition of the exhaust gases leads to low efficiency of the boiler unit, in particular, due to poor-quality fuel combustion. Therefore, in modern operating conditions of boiler units, it is relevant to develop technological solutions focused on finding and minimizing the causes and mechanisms of the formation of harmful substances in exhaust gases. Due to the fact that replacement of outdated boiler units with new ones requires significant capital investments, a promising direction is the modernization of existing boiler units. It is a low-cost and efficient way of rational use of fuel while simultaneously reducing the level of harmful substances in exhaust gases. It remains relevant to ensure the functioning of the control systems for the composition of the air-fuel mixture (AFM) with a given speed and high reliability of maintaining the excess air ratio (EAR) at the stoichiometric level. In the article the high-quality algorithm is proposed for the operation of an automatic control system for the combustion of fuel in boilers of medium and low power by regulating the ratio of the components of the AFM for the burner with feedback according to the signals of the oxygen sensor. The algorithms for the operation of the frequency regulator of the ratio of the components of the AFM in various operating modes are considered. The developed algorithms allowed maintaining the stoichiometric air-fuel ratio in the boiler furnace, reducing the level of toxic emissions into the atmosphere and increasing the boiler efficiency by optimizing the fuel combustion process. The AFM ratio programmer is made in the LM Programmer technical programming environment and works with Windows operating systems (XP, Vista, 7, 8, 10) and oxygen sensors manufactured by Bosch. The visualization of the control process of the fuel combustion process is made in the technical programming environment LogWorks 3 and operates in the environment of Windows operating systems.

Capture of Pollutants from Exhaust Gases by Low-Temperature Heating Surfaces

One of the most effective methods towards improving the environmental safety of combustion engines is the application of specially prepared water-fuel emulsions (WFE). The application of WFE makes it possible to reduce primary sulfur fuel consumption and reveals the possibility of capturing the pollutants from exhaust gases by applying condensing low-temperature heating surfaces (LTHS). In order to realize such a double effect, it is necessary to investigate the pollution processes on condensing LTHS of exhaust gas boilers (EGB), especially the process of low-temperature condensing a sulfuric acid vapor from exhaust gases to investigate the influence of condensing LTHS on the intensity of pollutants captured from the exhaust gases. The aim of this research is to assess the influence of the intensity of pollutants captured from exhaust gases by condensing LTHS in dependence of water content in WFE combustion. Investigations were carried out at a special experimental setup. The processing of the results of the experimental studies was carried out using the computer universal statistical graphic system Statgraphics. Results have shown that in the presence of a condensing heating surface, the degree of capture (purification) of pollutants from the exhaust gas flow is up to 0.5–0.6.

Evaluation on the Performance of Automobile Engine Using Air Injection Nozzle in the Intake Manifold

In the present study, a nozzle was used to improve the flow performance of an intake manifold, and its effects on the automobile engine output and the exhaust gas were experimentally studied. It was found that the engine output of a vehicle with a mileage of 30,000 km increased by 4.7% and 6.5% when nozzles with diameters of 5 and 2.5 mm were used. In addition, the engine output of a vehicle with a mileage of 180,000 km increased by 3.3% and 13.3% when nozzles with diameters of 5 and 2.5 mm were used compared to those of the same vehicle when no nozzle was used. Thus, using a nozzle for the inflow of outside air created a uniform combustion environment to improve the engine output and reduce harmful exhaust gases, such as hydrocarbon, carbon monoxide, and nitrogen oxides, by generating vortexes inside the intake manifold and increasing the degree of mixing. Furthermore, the smaller nozzle with a diameter of 2.5 mm had greater effects.

The Analysis of the Possibility of Feeding a Liquid Catalyst to a Coal Dust Channel

This article presents the concept of a method of improving the dynamics of combustion in boilers operating in power plants, cogeneration plants, and heating plants by introducing a catalyst that is fed with a carrier in the form of droplets. Thanks to the proposed method, a greater degree of fuel burnout can be obtained, which, in turn, results in lower energy consumption in the case of producing the same amount of power. The parameters of the emitted exhaust gases and ash are also improved. The method described in the article involves the adding of a catalyst to the dust pipe of the boiler, which improves the combustion parameters. The catalyst was implemented using a sprayer/nebulizer. In order to obtain the correct flow parameters, the sprayer was modeled using CFD calculations. The calculations include trajectories, velocities and concentrations with regards to various flow parameters. Particular attention should be paid to the model of the evaporation of moving droplets. The results of these calculations enable the parameters that guarantee that the catalyst reaches the dust channel outlet in the desired form to be assessed. The analysis is an introduction to experimental research that is carried out on a medium and large scale.

AN OVERVIEW: ENVIRONMENTAL AND ECONOMIC STRATEGIES FOR IMPROVING QUALITY OF SHIPS EXHAUST GASES

In spite of the fact that most of different transport means have achieved a significant reduction of their emissions quantity during the last few years; maritime field still suffers from the steady increase in the quantity of exhaust gases emitted from ships. As a result, the International Maritime Organization was prompted to issue a set of regulations for facing the seriousness of those emissions. The present paper handles the different methods which can be used to reduce the environmental damage caused by ship emissions. Through the study of the advantages and disadvantages of ships, emission reduction strategies; use of natural gas, selective catalytic reduction and sea water scrubbing systems have appeared as the best ways that can be utilized to reduce the environmental harms caused by ship emissions. Applicability of these methods aboard ships could vary from ship to another. Two high-speed passenger ships of different age were studied to evaluate the importance of applying these strategies. The results showed the possibility to attain valuable emission reduction percentage by using of selective catalytic reduction and sea water scrubbing systems, but they will be of high initial cost and will increase operating cost of both ships. On the other hand using of LNG as alternative fuel will be more convenient from the point of view of environment and economic issues for the newer existing ship.