Ion V. Ion

"Dunarea de Jos" University of Galati

Recent discoveries in the field of using blends of essential oil, alcohol and diesel in diesel engines open new perspectives for optimizing performance and reducing pollutant emissions. This work focuses on evaluating the combined effects of these blends on engine performance parameters and pollutant emission profiles, providing insight into the be...

Waste heat recovery from exhaust gas is one of the most convenient methods to save energy in internal combustion engine-driven vehicles. This paper aims to investigate a reduction in waste heat from the exhaust gas of an internal combustion engine of a serial Diesel–electric hybrid bus by recovering part of the heat and converting it into useful po...

The paper presents the possibility of floating photovoltaic farms on the reservoirs of the Olt river in Romania. For the analysis, a database with the solar irradiance evolution for one year in the four possible locations was created, using the PVGIS-SARAH2 database. The locations were chosen according to the surface area of the reservoir, geograph...

The aim of this paper is to provide a comprehensive overview of how electricity is produced from different sources and the electricity needs of the consumer. According to the Green Deal pact, the objective is to gradually reduce polluting emissions in the energy sector by 2050. In the meantime, the CO2 intensive thermal power plants (those using co...

The need for reducing fossil fuel consumption and greenhouse gas (GHG) emissions in internal combustion engines has raised the opportunity for the use of renewable energy sources. For the progressive replacement of fossil fuels like diesel, those derived from the sustainable management of forest resources may be a good option. In Portugal, pine tre...

Due to the benefits of the recirculating aquaculture system (RAS), many fish farmers are choosing this system. Some farmers chose indoor RAS, where fish tanks are kept inside buildings or greenhouses. Heating the buildings and the makeup water requires a substantial amount of energy since optimum growth temperatures exceed the normal temperature of...

The paper aims to apply the technical knowledge of recreational vehicles and the skills of using CAD applications for the design and construction of a steel profile frame. After the synthesis of the specific theoretical elements, from the specialized literature, the paper explores subassemblies of a kart, for which it proposes modeling studies. One...

The primary role of the suspension is to ensure the comfort of the passengers but also to protect the vehicle components against mechanical shocks caused by uneven road. It is designed for stability and sudden damping. The suspension system must first and foremost ensure the safety of the passengers of the vehicle but also their comfort. The paper...

In spite of the tremendous advances in computing power and continuous improvements in simulation software made in recent decades, the accurate estimation of wind turbine performance using numerical methods remains challenging. Wind turbine aerodynamics, especially when operating outside of the design envelope, is highly complex: blade stall, lamina...

Combustion in ultrasonic field is a promising combustion technology as it provides high combustion efficiency and low pollutant emission. Imposing acoustic oscillations on flame front enhances the turbulent mixing, resulting in reduced NOx and CO emissions and reduced flame length. The acoustic field can be generated by using two types of devices:...

One way to reduce the heat loss of the steam boiler is to reduce the blowdown rate and recover the heat from the purged water. Purging the boiler, although necessary, represents a loss of treated water and a loss of heat because the purged water is water brought to saturation. Blowdown recovery must be done according to the available users/consumer...

Water injection in internal combustion engines is mainly used for additional cooling of the combustion chamber and knock suppression. The main advantages of the water injection are the potential for the enhancement of the performance of the engine. Studies conducted so far have aimed to track engine performance at maximum load and fuel consumption...

In order to evaluate the greenhouse gas (GHG) emissions from a reservoir or from several reservoirs in a country or a climatic zone, simpler or more complex models based on measurements and analyses of emissions presented in the literature were developed, which take into account one or more reservoir-specific parameters. The application of the mode...

Municipal solid wastes (MSW) are, through the amount generated and energy content, one of the energy resources that can successfully contribute to covering energy consumption at local or regional level. The integration of this resource in modern energy systems can increase the penetration of renewable energy resources in energy supply. One of the m...

Identifying a modeling procedure of biomass thermal decomposition that is not only simple enough to implement and use, and computationally efficient, but also sufficiently accurate for engineering design activities, and with a spectrum of applications as broad as possible is a very difficult task. The authors propose a procedure which consists of t...

Energy and economic performance of an organic Rankine cycle (ORC) system designed to recycle waste heat of a steam boiler was analysed. Optimisation of ORC system was performed by using the Cycle-Tempo software and the REFPROP program. The selected working fluid was R245fa. For the exhaust gases temperature of 163°C and mass flow rate of 11.83 kg/s...

The main source of energy for the propulsion of automotive and trucks is still internal combustion piston engines. These are constantly improved in such a way as to achieve the lowest possible consumption of low-emission fuel. The results of the simulation of new technologies are confirmed in experimental stands, thus being the basis for the develo...

The numerical simulation of biomass combustion requires a model that must contain, on one hand, sub-models for biomass conversion to primary products, which involves calculations for heat transfer, biomass decomposition rate, product fractions, chemical composition, and material properties, and on the other hand, sub-models for volatile products tr...

The energy, economic and environmental analysis of a solar heating system with seasonal heat storage integrated into a district heating system based on natural gas boiler was performed. The solar collector field has a surface area of 8720 m2 and the pit seasonal heat storage has a volume of 10000 m3. This system covers 79% of the total yearly heat...

The municipal solid wastes (MSW) can be turned into resources through recycling and energy recovery. To obtain the maximum amount of energy, the appropriate technology must be applied to waste treatment. The composition and characteristics of municipal solid wastes are determinant for technologies choice for MSW in a city/region. Municipal authorit...

The low-enthalpy geothermal sources can be efficiently exploited for heat and power cogeneration by using the KCS-34 Kalina cycle systems. The maximum power for given heat source temperature and cooling temperature is obtained for a certain value of the ammonia-water solution concentration and turbine exit pressure. The Cycle-Tempo simulation softw...

The main role of the piston is to vary the dimensions of the combustion chamber in internal combustion engine. The piston is in contact with the hot gases resulting from combustion. In addition to thermal stresses, depending on the operating mode of the engine, the piston is required to alternate the inertial force. Therefore, the steel piston unde...

This paper presents an experimental study on the potential use of new type of composite as insulation material. The composite material (AACW-UPR) was synthesised through mixture between the Autoclaved Aerated Concrete Waste (AACW) as filler and Unsaturated Polyester Resin (UPR) as matrix. Several samples of the composite material with different UPR...

The connecting rod along with the crankshaft turn the translation movement of the piston into rotation. The alternating forces acting on the connecting rod caused micro-fissures, resulting in materials breaking at much lower forces than the maximum allowable stress. This work presents the finite element analysis to determine the fatigue strength of...

An experimental and a numerical simulation were conducted to analyze the field velocity of a fully developed turbulent incompressible flow behind a descending step. The laser Doppler anemometry was used as measurement technique. The Reynolds number of the flow was 62000. A Fluent simulation of the flow for the same geometrical and flow conditions a...

The energy conversion systems should have high energy efficiency to conserve the resources, a reduced environmental impact (low greenhouse gas emissions) and a low cost of delivered energy. By economic analysis which takes into consideration the taxes that have to be paid for pollutant emitted into atmosphere of a combined cycle cogeneration power...

In the present study, fluid flow around a circular cylinder, a classical application in practice, is investigated by means of the numerical modeling. The numerical modeling is performed with ANSYS CFD application. Once computational domain and meshing parameters had been selected, boundary conditions were established (Boundary Conditions) and then...

The present paper focuses on eductor pumps processes during operation to find the appropriate geometry for achieving the highest efficiency. Numerical modelling is performed with ANSYS Fluent. In the numerical modelling process, computational domain parameters, as well as boundary conditions, were set for two eductor geometries under comparative an...

The paper presents the energy and economic impact of combined heat and power generation technology integration in a sunflower oil mill by exploiting the own biomass resource, the sunflower husk. The energy performance of integrated biomass gasification combined heat and power (CHP) plant consisting in a fixed-bed downdraft gasifier, a gas turbine a...

Farm scale biogas plants most often use internal combustion engine-based combined heat and power (CHP) plant. In some cases (during summer) the heat demand is reduced and therefore a solution to increase the CHP plant efficiency must be found. One way could be the integration of an organic Rankine cycle (ORC) system to produce electricity and heat...

When modelling the wind speed in a given location, the probability distributions prove to be a useful tool. In this paper, the wind power density in an urban and a suburban location in Constanta county, Romania, have been analyzed during the period January 2017 - December 2017, based on the hourly measured mean wind speed data. In this study, the R...

This article states the problems with the use of central heating stations, as well as the need to introduce individual heat points. As a result, the authors considered the issue of improving the energy efficiency of heat supply systems in Russian cities while replacing central heating stations with individual heat points. The beneficial effects of...

A numerical simulation has been performed to study the biogas combustion in a burner with premixed flame developed under a high intensity small-scale turbulent environment, corresponding to high Karlovitz conditions. The CFD simulations were validated against experimental data for burner running with methane (measured temperatures along the radiant...

This work aims at analyzing the current stadium of research on building-up of the sand dunes and at being the starting point for a much detailed analysis on the topic. Throughout this essay practical studies are presented on the erosion, migration and building-up of sand dunes in the Sahara Desert; studies based on on-field measurements. Then there...

The overall objective of this research is to conduct an analysis of biomass drying process. This paper investigates the effect of various drier inlet parameters such as sawdust moisture content, particle diameter and drying gas temperature on moisture content of dry sawdust and hot flue gases and their temperature profiles along the length of the d...

In the current context of continued growth in energy prices worldwide and concern to support global efforts to improve the climate, insulation the exterior walls of the building is a well-known strategy to increase the energy efficiency of buildings. This paper presents the results of a study on increasing energy efficiency in collective residentia...

District heating is facing a strong technical and economic crisis in Romania. Besides the inheritance of systems with structural deficiencies, the lack of a vision of restructuring / development is the critical factor that can no longer be ignored. The outdated systems-inefficient systems, network losses and high prices of the heat energy resources...

An air-to water heat pump was implemented in a school placed in rural area near Galati city. This facility was monitored for two years period. The implementation of the heat pump was considered because there is no heating or natural gas network in the village. This study presents an experimental thermo-economic analysis of this type of heat pump, u...

The mCCHP-SE-RES system is defined as a particular combined cold, heat, and power system, which is distinguished in that it is a microgeneration system (mCCHP) dedicated to residential building, the CHP unit is a Stirling engine (SE), and the primary energy is obtained from renewable energy sources (RES). In this chapter, the last feature is presen...

In this study a solar-biomass hybrid heating system is analysed from energy, exergy and economic point of view. The analysed system was designed taking into consideration the recommendations of previous optimisation studies of combined solar –biomass heating systems. The system includes two heat storage tanks as a measure to reduce the number of st...

Heating boilers loses much of the heat developed by the combustion evacuating flue gas at high temperatures. To recover as much of this heat, flue gas has to be cooled below the dew temperature using different systems. Selection of the heat recovery systems requires a thermodynamic and economic analysis. The most important parameters influencing th...

The present contribution describes the investigation of a solar air collector for space heating in order to develop more efficient and cost effective energy process. Various configurations of absorber and different air flows through the collector were tested. The influence of the air mass flow on the air outlet temperature and thermal efficiency ha...

The NO x and CO emissions are regulated pollutant emissions. In order to have an insight into the degree of the amount of pollutant emission, especially at the modification of combustion conditions in the furnace is necessary to know the generation mechanisms and the influence of different parameters on their formation. In this paper, the mathemati...

The heat treating furnaces are one of the largest energy consumers in the manufacturing sector and therefore many techniques to improve their energy efficiency have been developed. One of them is recovery of heat contained in exhaust gases and to use it to preheat combustion air/charge or to generate steam. The maximum amount of recovered heat is o...

Effect of Energy Modernisation of a Steam Boiler on the Economic Efficiency: Increasing the efficiency of energy systems and reducing the environmental impact is one of the most important tasks for energy engineers. In this work the exergoeconomy analysis is applied to a steam boiler in order to find the most effective measure of modernisation. The...

The CFD modeling of biomass combustion or gasification systems needs a description of the volatiles composition that is formed during devolatilization and char oxidation processes. The present model can be used as a submodel in the CFD modeling of combustion or gasification process. This study is a combination of relevant models and data available...

The paper presents the research results on the combustion of biomass briq-uettes made of various mixtures of sawdust and harvested crop residues (wheat straw, corn stover, and reed) in a small boiler with downdraft combustion, designed to burn wood or sawdust briquettes. The analysis of five types of biomass mixtures showed that their combustion pr...

Rezumat : Utilizarea biomasei ca un substitut parĠial al combustibililor fosili este importantă în obĠinerea independenĠei energetice ‫ڍ‬i atingerea obiectivelor protocolului de la Kyoto deoarece biomasa este o sursă de energie regenerabilă. Alegerea proceselor de conversie a biomasei în forme utile energetic depinde de tipul ‫ڍ‬i cantitatea de bio...

Turbulent shear flows containing high levels of instantaneous turbulence or mean reversed flow, separation and reattachment, occur in many technical applications. The purpose of this paper is to describe the topology of a separated/reattached flow, to present a set of measurements of the separated flow behind a backward-facing step, and to perform...

In Romania, the power sector has contributed as a major factor to the degradation of the environment by developing power plants operating on inferior coal without any atmospheric pollution control systems. For the old plants still in use there are several technologies to control the pollutant emission, which achieve different rates of reduction tha...

In this work, the reduction of greenhouse gas emission, and the energy saving by integrating solar collectors and photovoltaic panels in a Stirling engine based microcombined cooling, heating and power (mCCHP) system are studied. The mCCHP system consists of a natural gas Stirling CHP and an adsorber chiller. When the thermal outputs of the Stirlin...

In this work, the reduction of greenhouse gas emission, and the energy saving by integrating solar collectors and photovoltaic panels in a Stirling engine based micro-combined cooling, heating and power (mCCHP) system are studied. The mCCHP system consists of a natural gas Stirling CHP and an adsorber chiller. When the thermal outputs of the Stirli...

A heating, ventilation and air conditioning (HVAC) system consisting of a simplified building with one room was modelled and simulated considering both the internal and the external conditions. The numerical model was designed to concurrently take into account: (1) the internal buoyancy-driven convective heat transport, (2) the conductive heat flow...

The paper presents a computer modelling and experimental validation for the thermodynamic performance of parabolic trough solar collectors (PTSC) used in a micro-combined cooling,e heating and power (mCCHP) system. The thermal efficiency, fluid outlet temperature, heat gain and heat and optical losses of the collector are calculated depending on th...

An important domain of atomizers use is the liquid fuels combustion. Their performance depends strongly on the droplet size and distribution. There are many numerical and experimental studies dedicated to the atomization characteristics in the specialized literature. This paper presents measurements of droplet size distribution produced by a radial...

In this paper the combustion performance of briquettes made from pure reed in a domestic heating boiler is presented. The boiler is designed to work with wood logs and briquettes made from sawdust. The combustion technique used is the reverse combustion. The main combustion parameters (CO and NOx emissions, flue gas temperature, air excess, combust...

This paper presents experimental results obtained after using a radial gas-dynamic generator of ultrasound at one of the eight fuel oil injectors of an energetic boiler with a steam mass flow rate of 330t/h. It was followed the variation of the boiler thermal efficiency and the variation of the nitrogen oxides emissions, at the ultrasonic generator...

The recent improvement on Spark Ignition Engines has been the result of improved engine thermodynamic cycles, made possible by advances in technologies such as Variable Valve Timing (VVT) and Variable Compression Ratio (VCR). To evaluate the potential of these techniques a thermodynamic analysis is made. Numerical models were implemented in Matlab...

Zirconia stabilized with 8 wt.% Y(2)O(3) is the most common material to be applied in thermal barrier coatings owing to its excellent properties: low thermal conductivity, high toughness and thermal expansion coefficient as ceramic material. Calculation has been made to evaluate the gains of thermal barrier coatings applied on gas turbine blades. T...

The paper presents relevant information about the working principle of the geothermal heat pumps and a study, based on an original computer simulation, analysing the influences of the working conditions on the heat pump performances. After presenting some basic considerations about the geothermal energy and about the heat pumps working principle, t...

The flat-plate collectors have an important place a mong applications of solar energy system. The paper describes the design and testing of a solar air collector in order to develop more efficient and cost effective energy pr ocess. In the design of solar collector the energy and exergy analysis were used to establi sh the appropriate components an...

The depletion of energy resources has been of primary concern in the `70s and `80s. In recent years, the decline of the environment due primarily to our energy-related activities has become severe and raises serious concern too. For this reason, method to analyze, improve and optimize energy-intensive systems have to deal not only with energy consu...

We would approach the problem of optimization quoting some lines of the single book of artificial intelligence that we know to be written for thermal systems [2]: “The term optimization is one of the most misused concepts in the field of Engineering. When reading a technical report about some “optimization” performed on a process or a single compon...

The combustion and pollutant gases generation in a recovery combustion systems burning residual steel gases has been investigated. These artificial fuels are characterized by reduced lower heating values and high content of nitrogen (N2) and sulphuratted hydrogen (H2S). For a steady combustion of these fuels in the furnace there is also used an amo...