International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

Recently, Albania as a developing country is focusing on the energy efficiency in residential and industry sector. Residential sector has very high contribution energy consumption in Albania due to many construction buildings without energy efficiency standards implementation. Most of the contribute city is Tirana where energy consumption in residential sector is very high in comparison to the other cities in Albania. Our research work will be focused on analysis of the energy audit on a private residence apartment which is located in the area of Tirana. The purpose of this paper is based on the relevant standards and norms to give appropriate recommendations for the implementation of energy efficiency which would increase the energy performance of this building.

In this paper is performed energy evaluation of steam turbine from the solar-based combined cycle power plant which includes analysis of each cylinder and the whole turbine. Steam turbine has three cylinders – high, intermediate and low pressure cylinders (HPC, IPC and LPC). Observed turbine is interesting because it possesses steam cooling before its expansion through the last cylinder (LPC). Due to unknown steam mass flow rates through each cylinder, for the evaluation are used specific variables. The highest specific work is obtained in LPC, while the lowest specific work is obtained in IPC. The highest loss of a specific work is obtained in LPC (29.8 kJ/kg), followed by HPC (24.5 kJ/kg), while the lowest loss of a specific work is obtained for the IPC (19.5 kJ/kg). Regardless of higher loss in specific work, HPC has higher energy efficiency in comparison to IPC (95.08% in comparison to 95.02%), while the lowest energy efficiency of all cylinders has LPC (94.92%). For the whole observed steam turbine loss of a specific work is equal to 73.8 kJ/kg, while the energy efficiency of the whole turbine is 95.00%.

This paper presents an exergy analysis of a complex four-cylinder steam turbine, which operate in a coal-fired power plant. Analyzed steam turbine consists of high pressure single flow cylinder (HPC), intermediate pressure dual flow cylinder (IPC) and two low pressure dual flow cylinders (LPC1 and LPC2). The highest part of cumulative mechanical power (787.87 MW) is developed in IPC (389.85 MW) and HPC (254.67 MW), while both low pressure cylinders develop a small part of cumulative mechanical power (70.29 MW in LPC1 and 73.06 MW in LPC2). Cylinder exergy destruction (cylinder exergy power loss) continuously increases as the steam expands through the turbine. The lowest exergy destruction has HPC (13.07 MW), followed by the IPC (20.95 MW), while the highest exergy destructions are noted in low pressure cylinders (24.37 MW in LPC1 and 27.17 MW in LPC2). Cylinder exergy efficiency continuously decreases as the steam expands through the turbine. The highest exergy efficiency has HPC (95.12%), followed by the IPC (94.90%) and LPC1 (74.25%), while the lowest exergy efficiency of all cylinders is obtained in LPC2 (72.89%). Exergy efficiencies of LPC1 and LPC2 are much lower in comparison to other low pressure dual flow cylinders from comparable steam power plants. The whole observed steam turbine has exergy
efficiency equal to 90.20%.

The following paper reviews all the possible cases of coupled two-carrier planetary gears with four external shafts. An emphasis is made on the work of these gears with one degree of freedom, one input and one output shaft and brakes on the other two shafts . When switching over the gears, the speed ratio of the gear is changed, thus allowing the use in two-speed mechanical transmissions of technological lifting and other machines. Some relations are deduced for determining the speed ratios and the efficiency of all structural schemes.
Recommendations for the selection of the most appropriate structural scheme according to the current necessities can be made. A 3D model of the S13V3 two-speed, two-carrier gearbox was created to demonstrate the process of determining the viability of a particular gearbox layout.

The hybrid electric vehicles (HEV) are promising vehicles with low exhaust emissions and increased autonomy of movement including internal combustion engine (ICE) and electric motor (EM) which is powered by the battery (B) . The main advantage of HEV over classic cars is the reduced fuel consumption, especially in urban traffic [1]. This is a prerequisite for good energy efficiency of HEV, which is determined by the fuel consumption and consumption, respectively the regeneration of electricity of HEV. These values depend on many factors such as speed, mileage, acceleration, mass, drag, climatic conditions and more. The modelling of the energy efficiency of HEV is related to the study and structuring of the factors that determine the fuel consumption and electricity consumption and the dependencies between them and their connection and construction in a model. The model of energy efficiency of HEV gives a quantitative assessment of the fuel consumption and the consumption (regeneration) of electricity of HEV, according to the main influencing parameters. In addition, the HEV energy efficiency model indicates the influencing parameters and their analytical or experimental determination. The correct modelling of energy efficiency is related to the correct determination of energy parameters and their logical connection in a selected model. The optimal model of energy efficiency of HEV is built from these factors that can be directly measured or calculated, which increases the accuracy and reliability of the results. This article discusses building an energy efficiency model of a hybrid electric vehicle.

The article presents the results of development and research of methods and adjustment of modes of operation of the device for gas-discharge visualization for the most accurate and prompt determination of the psychophysiological state of human health in th e field of his professional activity. Determining the ability of a teenager to cope with certain intellectual tasks, both at the beginning of the educational task and at the end of the working day, is necessary for the rational use of human labor and to ensure the quality and efficiency of the educational institution as a whole. Factors influencing the quality of the process of obtaining and accuracy of processing in formation about the psychophysiological state of man with a device for gas-discharge visualization,among which the greatest influence are external factors such as human (correct preparation and conduct of the experiment), climatic (humidity, ambient temperature) , guidance of ele ctromagnetic fields from power-operated devices nearby), elimination, or at least minimization of which allows to increase accuracy (by 8-12%), reliability (by 3-5%) and reproducibility (more than 1.8 times) of results diagnosing a device for gas discharge visualization. The daily dependences of the psychophysiological state of the adolescent on mental load were obtained, which showed the following: the best indicators of the psychophysiological state observed in the morning (period from 10-00 to 12-00) in the absence of other physical and intellectual morning load. At the same time it is established that active rest for 40-60 minutes or change of mental exercises by physical (within 60-90 minutes) after mental loading, restores the previous psychophysiological condition of the teenager by 85-90% whereas passive rest within 120-150 minutes, allows you to restore the previous psychophysiological state of the adolescent by only 35-45%.

Remote Electric Vehicles (EV) charging could become a viable alternative to cable systems. This paper is dedicated to the ana lysis of the Strongly Coupled Magnetic Resonance (SCMR) serial-to-serial topology aimed at establishing the impedance matching and obtains the maximum efficiency and power transfer coefficient. The research was done by using a model of equivalent circuits, experimental investigation and finite-element modeling of the mutual inductance. Upon generalizing the results obtained from the analytical and experimental research as well as 3D modelling of magnetic fields using Comsol Multiphysics, the interrelationships between internal resistance of voltage source and load resistance, characteristic and loss resistances as well as the distance between coils (the strength of magnetic coupling) necessary to ensure maximum efficiency and power transfer coefficient were established. The results of exp erimental research and modelling of the active power transfer coeff icient were presented.

The article discusses the benefits of converting diesel to gaseous fuels, such as reducing the toxicity of engine exhaust gases, fuel costs and noise. It is also noted that the conversion of a gas diesel engine is technically simple and, if necessary, it is possible to operate on diesel fuel. The main focus is on improving the efficiency of the diesel engine by adjusting the fuel mixture so that the power of the gas-diesel engine and the diesel engine is the same under all load conditions. The influence of the explosive properties of fuel and its dosage on the characteristics of gasoline is estimated.

Handling with municipal solid waste nowadays is becoming a global challenge. Albania is facing equally this issue. Although, in recent years a considerable progress has been achieved, still the country is lagging behind the EU states. In generally, the overall progress is slow and the requirements set by the policy and legal framework are not met. However, in recent years in Albania there are some developments related to solve the waste treatment dilemma. Thus, the government chose the public-private partnership model to operate in this field. Therefore currently in Albania are proposed three waste firing plants, placed in Elbasan and Tirana, central Albania and Fier,
southwest of the country. The Elbasan waste to energy plant is in operation since June 2017. Another plant in Fier is projected to start operation soon. This article aims to optimize a 5.5 MWe waste to energy plant in the Albanian conditions. Parametric design of thermodynamic properties of the WtE plant based Rankine cycle model are presented in this study. Optimization of plant efficiency in relation to extraction pressure and feed-water temperature is some of the outputs of this study.

Transport infrastructure brings together conventional groundwork and innovative technologies in order to improve various aspects of transport system management and control. It enables anticipatory maintenance, planning and scheduling, resource management and aims to improve reliability and safety, increased capacity and asset utilization, better energy efficiency and lower emissions, higher customer service levels and increased economic feasibility. Transport infrastructures have long service life and great costs of building, manning, operating and maintaining throughout their life. Innovation and technology shifts proved to be important factors determining great changes in infrastructure potential and even determine its obsolescence. It is regarded as a concern throughout infrastructure’s entire life cycle and reflects changes in expectation regarding performances in functioning, safety and environmental effects.
Performance and failure are illustrated conceptually and represented in a simplified form considering the evolution of technology, the influence of innovation breeding new generation rail infrastructure, all the way through infrastructure’s service life.
According to the identified particularities, recommendations are to be made in order to insure a best practice in lifecycle management and transport infrastructure renewal in the context of improved reliability, safety and efficiency.

Research, optimization and practical implementation of a Small Hydropower Plants as a source of clean electricity are one of the actual tasks in the current energetics, which is virtually impossible to solve without powerful computer support due to the strongly nonlinear nature of such systems. The article presents an overview of the most common simulation model schemes of Small Hydropower Plants, whereas explores the sub-models of its individual subsystems. The hydraulic turbine is considered as a core of the hydropower plant, whose efficiency calculation is analytically demanding and dependent on parameters that are often obtained only by theoretical estimation. In the article a fuzzy system was used to create its model based on measured operating data on the turbine flow rate and the height of its water column without the need to know the turbine parameters. Such a model is applicable in practice for the design of an energy-optimized hydroturbine control as well as to the effective determination of the deterioration rate. The correctness of the results was verified by simulation measurements in the MATLAB program.

There are growing appeals for the tilting chamber (TC) technology equipped with the “PTC-S” device, which is a profound improvement of the technology of mechanized harvesting of cereals, fodder and oilseeds; and other existing technologies in the field of transportation of beveled crop into the threshing and shredding chamber, etc. That is why TC equipped with “PTC-S” refers to the new generation of working tools for transporting the crop from the harvester or pick-up to the threshing and separating device of the harvesting machine. The development has significant advantages, among which the main ones are: a significant increase in energy efficiency, reduction of quantitative and qualitative grain losses during harvesting, etc.