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

Paper deals with a newly designed three-phase asynchronous electric motor with an application as a traction motor for driving compact battery-powered electric vehicles mainly in urban environments. The main characteristics of the motor are presented. The problems and solutions related to the sizing and optimization of the motor in the design according to various criteria and conditions are analyzed, with energy efficiency being the main determining factor.

Application of different retrofitting technologies can play a significant role in reducing energy consumption of existing buildings. This research work analyses a building in Cork (Ireland) where underfloor heating system, and natural ventilation are used to maintain comfort conditions. Underfloor heating system is the main electricity consumer of this building. Different energy efficient technologies were implemented and analyzed in terms of reducing electricity consumption through an energy software. These technologies include replacing illumination with high efficiency light; replacement of electric motos with high efficiency; introducing underfloor heating time scheduling turning on and off based on predicted weather condition; installation of presence sensors to switch ON/OFF lighting. Finally, it was decided to implement underfloor heating time scheduling as energy efficient technology to be analyzed because of limited budget available and high return on investments provided by applying this method. Result analysis shows that electricity saving on bills was about 20% on monthly basis compared to previous consumption.

With the developing food industry applications, the use of gastronorm containers is also increasing rapidly. It is widely used to transport, cook, preserve and serve gastronorm containers and food products. In line with international standards (EN 631-1, EN 631-2, etc.), the production process becomes more complex as the depth of gastronorm containers increases (from 20 mm to 200 mm / 6 different depths) and the process steps increase. Due to the errors arising from the process stages, there is an increase in the number of rejects, and thus energy efficiency is adversely affected. An automatic pressure balancing system design has been developed in accordance with the workflow in gastronorm container manufacturing with deep drawing technology. Providing the elimination of excess pressure steps and heat treatment needed in deep gastronorm containers (sizes and depths respectively: 1/2 200 mm, 1/3 150 mm, 1/3 200 mm, etc.), as well as the unique design of the integrated deburring machine, a significant innovation with industry 4.0 application has been imparted. Thus, in addition to the increase in product quality, it contributed to reducing unit costs by reducing high waste rates below 5%.

In recent years, the problem of food safety and traceability has been one of the difficulties faced by restaurant and hotel businesses. Food spoilage can occur at any stage of the food chain; most of all food spoilage is due to improper storage conditions in refrigerators. Increasing attention to food quality and safety requires the development of sensitive and reliable analysis methods as well as innovative technologies for maintaining freshness and food quality. Freshness is a factor that has both health qualities and features that affect customer satisfaction and business profitability. Within the scope of this study, simulation studies were carried out to improve the cooling performance with mathematical modeling on a horizontal commercial refrigerator (operating temperature: -2/+8°C) prototype. Along with the original design, evaluations were made with mathematical modeling according to many different variables (temperature, airflow distribution, etc.) that affect the cooling performance, and R&D gains were achieved in developing the prototype according to the most suitable working conditions.

Cookware is one of the indispensable equipment for commercial kitchens. The very large size of commercial cookware (up to Ø1200 mm) requires precision manufacturing processes. In our current manufacturing process, the fact that different processing stations are separate from each other and the processing stages are dependent on the workers, carrying risks in terms of occupational safety (cutting with scissors, grinding, etc.), prevents the product from being obtained with high processing quality and causes high wastage rates arising from the manufacturing process. In addition, it creates negative effects in terms of efficient use of energy and production time, causing an increase in unit costs. Within the scope of this study, the design and prototype production of an energy-efficient and work-safe innovative processing system for commercial cookware, based on R&D systematic studies, is carried out by international standards (EN ISO 12100, EN 614-1, EN 12983-1, etc.) and the results of our current manufacturing process. As a result of this research, occupational safety risks and excessive process steps are reduced, product quality and efficiency are increased, and thus production costs and energy efficiency are increased. Results are promising for further optimization.

The paper studies three of the most applicable wind-assisted ship propulsion systems: soft sails, Dynarig sails and Flettner rotors, in particular the wind forces on the sails. Traditionally, and still most reliably, these forces are determined by model testing in wind tunnels. Unfortunately, experimental results of different WAPS are quite scarce. On the other hand, the intensive development of Computational Fluid Dynamics (CFD) nowadays allows faster and more economical evaluation of aerodynamic forces and optimization of shapes. CFD modelling is applied here for evaluation of the aerodynamic forces on sails.

Paper deals with low power photovoltaic system implemented by means of flexible module. Flexible modules powered by sunlight are really a very interesting and promising novelty, being one of the newer alternative energy sources. A selected technical solution with specific characteristics of the individual components is presented. Measurements with digital measuring equipment were performed and experimental results were presented. In conclusion, it is summarized that the tested flexible module gives good results.

The building sector in our country has an important share of energy consumption. According to Eurostat data, final energy consumption in the residential sector was estimated about 35 % of the total consumption. On the other hand about 75% of the electricity consumption takes place in the building sector. It should be noted that currently this sector faces many challenge, as the quality of energy supply (heating) in public buildings and the residential sector remains at low rates. Nevertheless, reducing energy consumption is one of the main targets set in the National Energy Strategy 2018-2030. By 2030 this target suggests 15.5 % of the energy reduction. This study has at its core the assessment of energy consumption in a public building placed in the city of Durres. Determining the typology and thermophysical characteristics of the building is of primary importance. The evaluation of the energy performance of the building in the dynamic regime was carried out through the Hourly Energy Analysis (HAP) software. The implementation of energy efficiency measures is carried out taking into account the energy and cost criteria. A cost analysis of EE measures was performed using the dynamic Net Present Value method.

The Energy Efficiency Directive (2012/27/EU) established a set of binding measures to help the EU achieve its 20% energy efficiency target by the year 2020. New directive is called Energy Efficiency Directive (EED). According to INSTAT (Institute of Statistics) the share of non-residential building sector in Albania is approximately 20.6 %. Public buildings with all the sub-categories have a significant contribution on energy demand in buildings. Therefore, according to the new law No.116/2016 “For energy performance in buildings” since 2018 public buildings with area higher than 250m2 are subject of this law for certification of energy performance in buildings. Regarding the National Energy Strategy 2018-2030 Albania’s target is set to 15 % for energy savings in the sector. This article deals with identification of energy efficiency problems in the public building sector in Albania. Typology of the buildings mainly constructed before the 1990 has poor energy efficiency measures, due to the lack of the investments. Thermal imaging was identified as an necessary procedure for scanning of the building. Energy consumption and building characteristics through thermal imaging have been investigated with the aim to improve the energy performance of the public buildings. This will contribute to optimize the energy efficiency measures by
energy audits.

Since the fuel-saving idea was introduced in the 20th century, energy efficiency has gained attention in the transport industry. Ground vehicles (military, agricultural, and construction) usually operate on unprepared ground and need to overcome very complex and difficult ground obstacles, such as steep grade and very soft ground. The electrification of conventional vehicles, ranging from passenger vehicles and trucks to ground vehicles such as agricultural tractors, construction equipment and military vehicles, can poten tially offer improvements in fuel economy and emissions. Applied new systems reduce the amount of mechanical energy needed by the thermal engine by recovering the vehicle kinetic energy during braking and then assisting torque requirements. Energy management strategies for off-road vehicles are studied in this paper. With heavily fluctuating fuel prices, the total cost of ownership of loaders, excavators, and other classes of ground vehicles is nowadays strongly influenced by the fuel costs and there is growing concern about CO2 emissions as well as about the long-term availability of fossil fuels.

In specific energy saving measures, special attention is paid to driving technologies, as electric drives account for two thirds of industrial energy consumption. Paper deals with appropriate selection of electric motor with higher efficiency for shuttleless weaving grapple machine in order to retrofitting the electric drive. Such machines are not single pieces, but are always a certain set of a given production company. Once electricity consumption is reduced by investing in energy-saving engines, this can be the basis for intelligent and efficient energy management, accurate predictions of electricity consumption for future periods, which ultimately leads to increased energy efficiency of manufacturing enterprises.and systems.

In this paper is performed energy analysis of the whole low power steam turbine as well as energy analysis of all the turbine segments. Analysis of the whole turbine resulted with energy loss of 14642.48 kW and energy efficiency of 75.01%, what is in range with similar comparable low power steam turbines. Energy analysis of the turbine segments presents a different conclusion than the energy analysis of the whole turbine. The fifth turbine segment (S5) has unacceptable high energy loss and unacceptable low energy efficiency (energy loss of 6785.93 kW and energy efficiency of 26.87%), so it should be repaired as soon as possible. This comparison sh ow that proper energy analysis of turbine parts (segments) can detect the precise location of the problems during the turbine operation. Such analysis can be very helpful for the engineers because it allows detection not only the problematic components in the power plant, but also allows detection of the problematic parts of a component.