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This article addresses the problem that fluctuations in the torque of an internal combustion engine (ICE) lead to additional energy losses, as it causes fluctuations in the speed and kinetic energy of the car. These losses increase as the frequency of oscillations of the torque of the internal combustion engine approaches the frequency of free (natural oscillations) of the running gear of the car in the longitudinal direction. If there is an elastic connection between the traction force and the movement of the car, the movement of the latter can be represented as complex. At the same time, the portable movement is uniform, and the relative movement is oscillatory. This article presents the results of the study of these losses for cars with mechanical and combined electromechanical drive wheels. Analytical expressions are obtained, which allows to take into account additional energy losses including the tangential rigidity of the tire and the rigidity of the suspension in the longitudinal direction. When using a combined electromechanical drive of the drive wheels as well as in the case of a mechanical transmission of a car, the resonance is dangerous. But with the increase in the share of torque kem on the wheel generated by the electric motor, the relative additional energy losses for the movement of the car are reduced.

This paper outlines the prospect of obtaining water from atmospheric air by cooling it to the dew point temperature using refrigeration machines in order to partially reduce water scarcity in the arid regions of our planet. To minimize energy costs in the systems for obtaining water from atmospheric air, it is proposed to utilize solar energy with absorption refrigeration units (ARUs) acting as a source of artificial cold. The characteristic thermodynamic processes have been analyzed in a modernized ARU, capable of working at a lower thermal energy source's temperature than its analogs. The possibility has been studied to reduce the temperature of the heat source by including a solution vaporizer in the ARU scheme. The analysis involved an authentic method based on the balance of specific streams of ARU working body components and actual boundary conditions at characteristic points of the cycle. A limit was shown for the level of a minimum boiling temperature in the ARU generator (from 90 °C) when the systems for obtaining water from atmospheric air are operated under current climatic conditions. The simulation of heat-and-mass exchange processes during contact interaction between a steam-gas mixture and ammonia water solution was carried out. Based on variant calculations, it has been shown that the proposed ARU structure with an adiabatic solution vaporizer could work as part of systems to obtain water from atmospheric air at a hot spring temperature above 100 °C and constructively enough fits into the element base of standard models. It has been proposed to use two types of solar thermal energy sources to operate ARU. In a tropical climate, with vacuum solar collectors or solar energy hubs; in a temperate climate zone, with solar collectors with water as a heat carrier

The gas engine driven carbon dioxide heat pump designed for providing the heat, cold and electricity for industrial poultry house is proposed. The scheme differs from the known by using recuperative heat exchanger installed between the exhaust air duct of poultry house and heat pump evaporator and the heat curtain installed on the air duct after the evaporator. The air coming into the poultry house after the regenerative heat exchanger is supplied to the heat pump gas cooler. The heat pump produces heat of the required parameters of the input air and water for watering of poultry, space heating, etc. Heat pump compressor is driven by gas engine (GPA), by natural gas or biogas. The part of the gas-piston engine heat is used for adjusting the optimal heat pump mode and for regeneration of the absorbent in an evaporative cooler. The proposed technical solution of the above scheme provides a higher COP of the heat pump. Installing of heat curtain does not require the use of non-freezing solution to prevent icing of the air outlet of heat pump evaporator. The latter allows producing, besides electric power and heat, still cold (with the use off the adsorption-refrigerating machine) and provide drying air inlet evaporative cooler (if necessary).

The analysis of scientific works shows that the development of technology is ahead of the level of development of energy management. There are no clear comparisons of the energy efficiency of electrical technologies and heat technologies. Objective indicators of energy efficiency in various technologies of dehydration of raw materials not developed yet. In that article assumed that objective results for comparing energy efficiency in the processing of raw materials is obtained by the basis of system analysis of the entire energy conversion chain from fuel to finished product. The purpose of the work is experimentally proving the objectivity of this hypothesis. To achieve this goal, it is proposing to use the indicator of the energy share of fuel in the finished product and the amount of moisture removed when burning 1 kg of fuel, which does not depend on fluctuations in energy prices, which can vary and differ for different countries. The most important result of the work is the comparison of these parameters with the data for innovative equipment samples developed by the authors. The significance of the results obtained is that the evaporating devices developed by the authors are not inferior in efficiency to traditional ones, and make it possible to obtain concentrates up to 90 ° brix. Thus, for fuels with an oil equivalent of 40 MJ per 1 kg, traditional dryers can remove no more than 3 kg of moisture, cryoconcentrators – 20 kg.

The aim of research is to simulate the zones of solar radiation on the curved surfaces of the shells of high-rise buildings for the effective use of renewable solar energy. An urgent task is the development of tools that can substantiate the decision-making by designers about the location of solar thermal devices in the energy-efficient design of curvilinear high-rise buildings. The main attention is paid to high-rise buildings, is actively growing in modern megalopolises and requires a significant energy resource. To optimize the integration of solar thermal devices in high-rise buildings, it is important to take into account a set of design parameters, including parameters of surface shape and location in space. A feature of curved surfaces, considered in the study, is their aerodynamic properties, which provide them with the advantage of choosing among modern high-rise buildings. At the same time, the complexity of setting the parameters of a curved surface to determine the zones of solar radiation for the effective use of regenerative solar energy lies in providing reliable and convenient tools for optimizing decision-making. The study proposes an application of the method based on a discrete geometric model of solar radiation input on the surface of the shells of high-rise buildings, described by compartments of curved geometric surfaces. As a result of modeling, let’s obtain a family of lines of the same level of solar radiation on a certain curved surface for the given parameters of time and geographic location. As an example of simulation modeling, the performed calculations of the instantaneous model of the distribution of solar radiation on the compartments of the curved surfaces of an ellipsoid of revolution, hemisphere, hyperbolic paraboloid. On the basis of the proposed model for the distribution of solar radiation over curvilinear surfaces of buildings, the influence of factors arising in the design process is investigated: changes in the geometric parameters of the surface shape, orientation to the cardinal points, the formation of zones of its own shadow on surfaces. Calculations were performed and instantaneous solar radiation zones were constructed on the surfaces of a hemisphere, a hyperbolic paraboloid with various geometric parameters, taking into account different orientations relative to the cardinal points, and determining the zones of its own shadow. At this stage of the study, the result is an algorithm for constructing zones of different levels of solar radiation on curved surfaces of high-rise buildings. The advantage of the algorithm is the ability to analyze the results of changes in the design parameters of the surface of a high-rise building when placing solar systems on them. The proposed approach will provide a basis for automating the modeling process, will help expand the scope of solar systems in high-rise construction and increase the efficiency of their work

We have investigated the process of constructing the charts of electrical load, as well as electricity consumption, of many-storied apartment houses in a city's neighborhood, taking into consideration the fractal structure and the existence of a long-term dependence, inherent to self-affine stochastic processes. The results from studying daily, weekly, monthly, yearly charts have shown the presence of fractal properties and the existence of short-term and long-term memory. This makes it possible, in order to efficiently predict and control power consumption, to apply a fractal analysis, which establishes the dependence of future values on retrospective information. Feature of the current study is determining a critical value for the Hurst exponent, approaching which leads to that the system loses stability and enters an unstable state under which the parameters are changing rapidly. The Hurst exponent can be transformed into fractal dimensionality, which is a measure for the complexity of a load chart. In the theory of fractal sets and fractal geometry, of significant importance are the self-similar and fractal sets. By using the specified properties of the fractal, this study has proven the existence of a fractal principle in the formation of the dynamics of electrical load on civilian targets using the example of power consumption by many-storied apartment houses within a city's neighborhood. The calculation of the Hurst exponent has made it possible to determine that the series is persistent and suitable for adequate prediction and efficient energy consumption management. The relevance of the current research is predetermined by the application of a fractal analysis to electricity consumption pattern particularly by civilian objects, since the scientific literature analyzes and predicts the processes that form electric load structure on energy systems, at industrial enterprises

Energy consumption, environmental issues, product quality are actual problems related to grain drying processes. It is necessary to pay attention to designing new structures of energy-efficient grain dryers. A structure of an energy-efficient grain dryer based on thermosiphons has been designed; its energy consumption is 3.5...6.8 MJ/kg depending on surface temperature and air flow rate. The dryer includes a layer heater, a drying chamber, a heat generator, a heater, a noria for loading the product, and fans. The structural features of the dryer allow the drying process to be carried out without direct contact between the combustion gases and the product. The efficiency of the designed structure was evaluated for such indicators as heat transfer coefficients to the grain flow, specific energy costs, moisture content, the relative humidity of the air leaving the dryer. The values of coefficients of the heat transfer to the grain flow vary within 36...58 W/m2K at speeds 2.5...8 mm/s. An increase in the flow rate by 3.2 times leads to an increase in the heat transfer coefficient by 1.6 times. The moisture content of the air at the outlet of the dryer reaches 60 g/kg, while the relative humidity is 90 %, which is several times higher than the parameters for convective mine grain dryers. Energy consumption for drying at the surface temperature of thermosiphons Ts=142.9 °C for various grain flow rates is close to a minimum. The energy consumption is lower than in existing convective dryers. 21 % is spent on heating grain in the dryer; 54 % ‒ on moisture evaporation; and 23.6 % are losses. If we consider the energy spent on moisture evaporation usable, the efficiency of convective dryers is only 40 % while that of dryers based on thermosiphons is 54.1 %. It is expected that the designed structure could be a solution for small farmers in the post-harvest drying process