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

Paper deals with determining the permissible number of switches on per hour depending on the load and operating mode parameters – starting and stopping times, pause duration, etc. The criterion is that the overheating of the stator winding does not exceed the overheating at nominal mode and load. The basis of the chosen method is the assumption that the electric motor is assumed to be a conditionally uniform body, i.e. a body made of the same material with an infinitely large thermal conductivity and therefore having the same temperature throughout its volume under all possible modes and loads. The results of the calculations with a computer program
implemented are presented in tabular form.

The city of Korça is situated in the South-East part of Albania. Korça’s climate is partly Mediterranean and Continental, characterized by cold winter and relatively hot summer. The average annual temperature is 10.6 oC, while the average rainfall is 720 mm. Heating of Korça is not an unknown issue, although it still remains unsolved despite many efforts in this sector. This paper shortly describes the building typology and their thermal characteristics in Korça. After defining the heating demand of the Korça city, where as input in the model are used demographic data, climate data, building typology and heating system. Energy scenarios for heating of the city rely on a
baseline scenario where wood is used as an energy source. Heat pump and natural gas energy scenario have been used for this comparative study. Energy and cost analysis for three scenarios are discussed in this paper.

The formation features of transition metals borides at high temperatures and low pressures were investigated and discussed the conditions of formation, structure and wear properties of boride layers on the surface, formed in electron beam processing in a vacuum.

This article presents methods and means of increasing an efficiency of heat pump system and hot water supply for residential houses on the base of using of the heat pumps «air-water», solar collector of energy and ground heat exchangers. The technological scheme of energy saving heat pump system of the rural house taking into account local climatic conditions is described. The study determines typical temperature parameters hybrid heat pump system’s elements at cold days in heating season. The expediency of use of solar energy and heat of ground for preliminary heating of the cold external air arriving to the thermal pump «air-water» is proved.