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The paper considers how to decrease the concentration of nitrogen oxides in gas emissions of bakery enterprises. Nitrogen oxides (NOx) formed in the course of burning natural gas are responsible for more than 90% of an enterprise’s hazard category. So, it has been determined how much NOx is contained in exhaust gases emitted at different loadings on the floor of the oven at an enterprise, this parameter being the main characteristic of the effectiveness of ovens and their impact on the environment. The paper presents the results of experiments that have allowed determining the regression equations describing how the NOx quantity per unit of output in an enterprise’s exhaust gases depends on the amount of the fuel consumed and on the loading on the floor of baking ovens. The procedure of the experiments has been described, and the numerical results have been presented and analysed. It has been established that when making a loaf of wheat-flour oven-bottom bread weighing 0.9 kg, with 70% loading on the floor of an oven (PPC1381), the nitrogen oxides concentration in combustion products is 212.00 μg/m3, and the specific NOx formation is 292.25 μg/kg. The nitrogen oxides concentration is 152.00 μg/m3, and the specific formation is 306.00 μg/kg when the oven floor loading is 40%. If a similar range of products is baked in ovens Minel100 with the maximum-loaded and half-loaded oven floor, the production is accompanied by specific nitrogen oxide emissions of 239.50 μg/kg and 247.80 μg/kg respectively. When enriched buns of 0.1 kg are baked in ovens BN50 with the maximum-loaded and half-loaded oven floor, the process is accompanied by specific nitrogen oxide emissions of 209.20 μg/kg and 265.96 μg/kg respectively. The nitrogen oxides content in gases withdrawn from bakery ovens has been instrumentally measured. This has allowed obtaining regression equations of dependence of the specific NOx weight in gas emissions on the amount of fuel consumed and on the oven floor loading. It has been found that in the ovens considered, the nitrogen oxide formation per output unit decreased when the oven floor loading increased, because less fuel is needed to make up for the loss of heat accompanying the emission of fumes. The contributions of the argument parameters have been determined according to the regression model to estimate the quantitative dependence. The amount of nitrogen oxides depends on the oven floor loading. A mathematical model has been developed describing how nitrogen oxide formation depends on the oven floor loading and fuel consumption. The model can be used to introduce an industry standard of quantification of nitrogen oxides formed when manufacturing a unit of output.

One of the promising ways in environmentalizing marine internal combustion engines is the neutralization of harmful substances in exhaust gases through particular gas recirculation (EGR-technology). However, the use of such techniques conflicts with the engine's energy efficiency. In the work presented, the scheme-design solution of the exhaust gas recirculation system with using the heat of recirculation gases by an ejector refrigeration machine for cooling the air at the intake of ship's main engine is proposed. The effect of using the heat of recirculation gases for cooling the air at the intake of the engine is analyzed taking into account the changing climatic conditions for a particular vessel's route line. It is shown that the use of an ejector refrigeration machine reduces the air temperature at the entrance of the main engine by 5-15 ° С, which reduces the specific fuel consumption by 0.5-1.5 g/(kW∙h). This reduces emissions of harmful substances when the engine is running with recirculation of gases, in particular, NOx by 30-35%; SOx by 10-12%.

There are many ways and methods to reduce exhaust gases emissions on modern ships. One of the most effective ways to reduce NOx and SOx emissions is to use of exhaust gas recirculation (EGR technology). The EGR system disadvantage is an increase in back pressure through additional pressure losses in the scrubber and heat exchanger, which entails an engine fuel efficiency deterioration. Creating a reliable and efficient heat exchanger for cooling recirculation gases is a complex task due to deposits and pollution emitted by these gases. In the present work, the jet apparatus effectiveness named aerothermopressor is analyzed in the scheme with exhaust gases recirculation of the ship low-speed two-stroke engine. Aerothermopressor is a two-phase jet for contact disperse cooling, in which by increasing the heat from the gas stream the gas pressure and cooling are increased. The calculation of the characteristics of the engine was carried out, both in nominal, and in operating modes and in all possible range of partial loads. The installation of the aerothermopressor before the scrubber is proposed, which allows reducing engine thermal load. Increasing the pressure in the aerothermopressor by 0.2-0.4 ∙ 105 Pa (6-12%) allows reducing the back pressure in the gas exhaust system and thus reducing the load on the exhaust gas recirculation fan and when the engine load is higher than 75% in the cold zone, the fan is not needed, which additionally allows to reduce the specific fuel consumption. The parameters of the exhaust gases that are going to be recirculated and the processes of their gas-dynamic cooling in the aerothermopressor are based on the developed technique and program using the thermodynamic and gas dynamics equations. The proposed scheme-design solution allows at a high environmental friendliness of the existing exhaust gas recirculation system to provide a certain reduction in specific fuel consumption. It was determined that the engine specific fuel consumption has been decreasing when the aerothermopressor is used to 2.5-3.0 g/(kW·h) (1.5-1.7%).

A methodology and solid-state modeling results of the dust ejection suction process from the engine air inlet with exhaust gases by means of ejector, installed in the self-moving agricultural harvester damper, are given. The results of modeling are compared with the results of experimental researches; conclusions about gained data divergence reasons in some investigated parameters ranges are drawn. Investigated values dependences on changeable parameters are gained. Optimal ejector geometrics providing effective dust suction without engine work conditions deterioration are selected. Recommendations for ejection suction systems engineering are produced at self-moving agricultural harvesters’ development which is successfully used at OJSC “Gomselmash”.

Waste heat recovery for meeting the air conditioning demand of a ship is reported. An absorption refrigeration system is proposed. Water-LiBr is used as the working pairs for this purpose. A steady-state energy, exergy, and environmental analysis is done to compare the proposed system with the conventional system. Exhaust gases of auxiliary engines are used to vaporize high-pressure water. High-pressure steam is employed as a heat source for the generator of the absorption system. The results show that exhaust gases of the auxiliary engine as a permanent heat source suffice for the generator of the absorption system. For tropical conditions, the required power for the absorption system is much lower than that for the conventional system. (W ̇ demand for the absorption system is 0.02, while it is 88.28 for the conventional system). The second law of thermodynamics shows a 31% lower total irreversibility in the proposed system versus the conventional system. The use of the absorption system causes a USD 45,078 saving in the yearly penalty cost of CO2 emission. [ABSTRACT FROM AUTHOR]

A significant jump in the development of machine building technologies requires the adjustment of environmental indicators. The main sources of air pollution are vehicles with internal combustion engines. According to research data, the main share of toxic emissions is accounted for by the engine idle mode and constant load mode. Studies carried out to improve fuel efficiency of diesel engines which have been in operation for some time show the potential for increasing the efficiency by deactivating a portion of the cylinders. At the same time, the improvement of efficiency indicators varies within a wide range - from 4 to 30%. The larger the number of deactivated cylinders, the higher the fuel economy effect, but as the effective power increases, it is advisable to reduce their number. The potential for increasing efficiency by deactivating a portion of the cylinders is incorporated in all diesel engines in operation. The efficiency of cylinder deactivation is confirmed by experimental data obtained on various types of engines, including automobile, tractor, diesel locomotive, and ship engines. This method is known in engine building primarily as a means of increasing the efficiency of diesel engines at idle speed and small loads. It has been established that there is a decrease in the hourly fuel consumption to 33% of the rated effective power when engine cylinders are deactivated compared to operation without cylinder deactivation. A diesel engine was tested on a running-brake stand fitted with the necessary measuring and recording equipment and instruments, allowing for a maximum torque of 363 N·m at the crankshaft speed within 1200–3000 min−1. Our studies covered three engine operation options. It has been established experimentally that the specific indicator fuel consumption in the second mode, as compared to the first mode, decreases to 9% due to a decrease in the hourly fuel consumption at the speeds from 1600 min−1 to 2350 min−1. In the third mode, fuel economy at idle speed with a shutdown of the fuel supply and the drive of the gas distribution mechanism of the 2nd and 3rd cylinders was about 24% at the engine shaft speed in the range from 1200 min−1 to 2350 min−1. Upgrading the diesel engine using an electromagnetic fuel valve will pay itself off in about a year. A comparison of the experimental and theoretical data shows that their discrepancy in the whole range of the engine crankshaft speeds does not exceed 7%. [ABSTRACT FROM AUTHOR]

The paper considers how to decrease the concentration of nitrogen oxides in gas emissions of bakery enterprises. Nitrogen oxides (NOx) formed in the course of burning natural gas are responsible for more than 90% of an enterprise’s hazard category. So, it has been determined how much NOxis contained in exhaust gases emitted at different loadings on the floor of the oven at an enterprise, this parameter being the main characteristic of the effectiveness of ovens and their impact on the environment. The paper presents the results of experiments that have allowed determining the regression equations describing how the NOx quantity per unit of output in an enterprise’s exhaust gases depends on the amount of the fuel consumed and on the loading on the floor of baking ovens. The procedure of the experiments has been described, and the numerical results have been presented and analysed. It has been established that when making a loaf of wheat-flour oven-bottom bread weighing 0.9kg, with 70% loading on the floor of an oven (PPC1381), the nitrogen oxides concentration in combustion products is 212.00μg/m³, and the specific NOx formation is 292.25μg/kg. The nitrogen oxides concentration is 152.00μg/m3, and the specific formation is 306.00 μg/kg when the oven floor loading is 40%. If a similar range of products is baked in ovens Minel100 with the maximum-loaded and half-loaded oven floor, the production is accompanied by specific nitrogen oxide emissions of 239.50μg/kg and 247.80μg/kg respectively. When enriched buns of 0.1kg are baked in ovens BN50 with the maximum-loaded and half-loaded oven floor, the process is accompanied by specific nitrogen oxidee missions of 209.20μg/kg and 265.96μg/kg respectively. The nitrogen oxides content in gases withdrawn from bakery ovens has been instrumentally measured. This has allowed obtaining regression equations of dependence of the specific NOx weight in gas emissions on the amount of fuel consumed and on the oven floor loading. It has been found that in the ovens considered, the nitrogen oxide formation per output unit decreased when the oven floor loading increased, because less fuel is needed to make up for the loss of heat accompanying the emission of fumes. The contributions of the argument parameters have been determined according to the regression model to estimate the quantitative dependence. The amount of nitrogen oxides depends on the oven floor loading.A mathematical model has been developed describing how nitrogen oxide formation depends on the oven floor loading and fuel consumption. The model can be used to introduce an industry standard of quantification of nitrogen oxides formed when manufacturing a unit of output. [ABSTRACT FROM AUTHOR]

The results of the development and research of a promising full-flow dynamic method of variable volume sampling to determine in laboratory conditions the values of mass emissions of pollutants from the exhaust gases of automobile engines are presented. Emissions are determined by the test procedures for complete vehicles in driving cycles, or separately of their engines in motor test cycles. Current mass emissions of pollutants are calculated from time-synchronized instantaneous concentrations and instantaneous flow rates of the mixture of exhaust gases and air. In the mixing chamber, which serves the exhaust gases and air, also serves calibration gas mixture with a flow rate that is changed in accordance with the periodic function. This is used to determine the transfer functions of the inverse calculation of the instantaneous flow rate of the mixture of exhaust gases and air, and the current values of the concentrations of pollutants at the time of sampling. Mass emissions of gaseous pollutants are calculated as the difference between the total mass emissions of pollutants and the mass emissions of pollutants that are added with the flow of the calibration gas mixture. The performance of the dynamic full-flow variable-volume sampling method is proved by comparing the calculated (carbon balance method) and directly measured fuel consumption by cars in driving cycles. The difference between the directly measured and calculated (for certain mass emissions of pollutants) fuel consumption does not exceed±3.5 %. This is a satisfactory result, taking into account, in particular, the measurement uncertainty in the dynamics of rapidly changing concentrations of pollutants, diluted exhaust gas flow rate, fuel consumption, and the determination of carbon content in the fuel. Fundamentally new possibilities have been obtained for measuring the mass specific emissions of pollutants by forcedignition engines and modern diesel engines (Euro-6 environmental class) and promising low-emission vehicles. [ABSTRACT FROM AUTHOR]

During planning of green planting in cities, vital status of plants which make up the groups is taken into account first. The methods of assessment of morphological and physiological parameters of the vital status are the most widely used ones. In the process of work, the vitality of woody plants was evaluated under the impact of anthropogenic pressure in the framework of the physiological state, which is determined to a great extent by the content of chlorophylls in the leaves of trees. The content of green and yellow pigments was studied in the drought conditions of vegetative period for 8 species of trees which are common in green planting of cities in the South- East of Ukraine. Stable species (Populus simonii Carriér, Populus × canadensis Moench) respond by increase in the content of chlorophylls at maximum air temperatures during the growing season. Nonsufficient-stable species show significant effect of the amount of rainfall on the changes in chlorophyll content in leaves, which is the evidence of their adaptive capacity. Deterioration of the functional state of trees in street and park planting compared to suburban territories was revealed, confirmed by reduced chlorophyll content and increase in carotenoids. For the further introduction in the urban greening of industrial cities of steppe zone, the models of influence of the meteorological factors on the content of green pigments in the leaves of Polulus simonii and Acer pseudoplatanus L. are proposed. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare and evaluate the production of exhaust emissions from a vehicle with a petrol engine with the Euro 4 emission standard and powered by petrol and LPG (liquefied petroleum gas). The paper presents new possibilities for monitoring exhaust emissions using an exhaust gas analyzer. At the same time, it points out the topicality and significance of the issue in the monitored area. It examines the impact of a change in fuel on emissions. This change is monitored in various areas of vehicle operation. Measurements were performed during real operation, which means that the results are fully usable and applicable in practice. The driving simulation as well as the test conditions correspond to the RDE (Real Driving Emissions) test standard. A commercially available car was first selected to perform the tests, which was first measured in the original configuration (petrol drive). Based on real-time RDE driving tests, it is possible to determine the number of exhaust emissions. Subsequently, the same measurements were performed with the same vehicle, but the vehicle’s propulsion was changed to LPG. The vehicle was equipped with an additional system that allowed the vehicle to be powered by LPG. The results from the individual driving tests allowed the determination of the exhaust emissions. Emissions of CO (carbon monoxide), CO2 (carbon dioxide), HC (hydrocarbons), and NOx (nitrogen oxides) were monitored as a matter of priority. Through the driving tests, it was found that the gasoline combustion produced higher CO (1.926 g/km) and CO2 (217.693 g/km) emissions compared to the combustion of liquefied gas, where the concentration of the CO emissions was 1.892 g/km and that of the CO2 emissions was 213.966 g/km. In contrast, the HC (0.00397 g/km) and NOx (0.03107 g/km) emissions were lower when petrol was burned. During LPG combustion, the HC emissions reached 0.00430 g/km, and the NOx emissions reached 0.05134 g/km. At the end of the research, the authors compared the emissions determined by real driving (in g/km) with the emission values produced by the emission standard EURO 4 and the certificate of conformity (COC). Practical measurements showed that the vehicle produced excessive amounts of CO when burning gasoline. This production is 0.926 g/km higher and 0.892 g/km higher when burning LPG compared to the limit set by the Euro 4 Emission Standard. The difference is even greater than the limit value stated in the COC document. For other substances, the monitored values are in the norm and are even far below the permitted value

This paper presents the results of research on exhaust gases from landfill gas combustion. The measurements were carried out in a reclaimed landfill in Kiełcz (a passive degassing system based on gas flare). The research concerned the effects of selected exhaust gas purification technologies (platinum catalyzer on a ceramic carrier, molecular sieve, copper(II) oxide) for the quality of exhaust gases, and their particulate matter content. This paper aims to indicate which catalytic systems are most suitable for this gas type and their most efficient positioning in the flue gas duct. Due to increasingly stringent emission standards, the outcomes presented in this article could be helpful for landfill owners who wish to avoid paying fines for not complying with applicable limits. The measurements were carried out using a flue gas analyser, a particulate matter analyser fitted with a probe, and four thermocouples connected with the data recorder. The research outcomes determined the percentage reduction of pollutant emissions into the atmosphere (CO, NOx, and particulate matter) using catalysts. The potential benefits of using catalysts in landfill gas combustion systems due to their operating temperature ranges are discussed.

In contrast to fossil fuels, hydrogen H2 has little environmental impact. It may be produced from water, which is a renewable resource. The benefits of H2 in terms of the ignition portion of diesel fuel and also the influence of the H2 content on the NOx emissions are considered. Promising hydrogen-bearing materials are Brown's gas (HHO) and ammonia (NH3). The electrical energy produced by the vehicle's generator is used to split water (H2O molecules) into the simple elements hydrogen (H) and oxygen (O). The gas obtained by electrolysis is known as Brown's gas (HHO gas). Brown's gas is a possible fuel for internal combustion engines. [ABSTRACT FROM AUTHOR]