Analysis of the influence of the internal heat capacity of the university building and weather-dependent regulation of itp on the efficiency of the heating system in standby mode

When assessing the thermal condition of the building and the parameters of the microclimate of the premises, the main factors influencing its thermal inertia were identified and taken into account. An assessment of the influence of the resistance of enclosing structures on the efficiency of the heating system, taking into account the influence of external and internal climatic parameters in the dynamic mode. It is shown that the time factor and depth of regulation, as well as the outdoor air temperature are important factors. Researches are carried out and the expediency of introduction of a duty mode of heating of buildings of HIGH SCHOOLS is estimated. The given algorithm of control of process of heat release (especially in the presence of a point of "breaking" - average (them) on the schedule) in addition increases accuracy of the decisions of the specified problems and reduces a temperature deviation by 4 ÷ 6 ° C in comparison with usual ("linear") dependence that allows to correct more precisely release of the heat carrier in system of heating of a structure at introduction of a standby mode. It was found that it took about 6.5 hours to achieve normalized air temperature and space heating in the forced (after a long stay on duty). It is shown that the heat consumption of the system in such conditions of its operation compared to the nominal mode increased by 25 % (taking into account the limit value of the specific allowance from table H1 DBN B.2.5-67: 2013 "Heating, ventilation and air conditioning"), but for the entire period the action of the standby mode savings amounted to about 6-8% of energy consumed. Taking into account the design of the outer walls of the object of study, the temperature graph of the heating system was adjusted taking into account the value of the internal heat capacity of the building when implementing on-duty heating, which, according to preliminary estimates, will: improve comfort in the room; to reduce heating costs of the educational and administrative building of NULES of Ukraine by 10-12 % for the heating period. Key words: microclimate, internal heat capacity of a building, standby mode, heating system, heat loss

Research of pneumatic conveyor for overloading of fuel pellets

The constant development of the country's agricultural sector allows the production of biofuels, such as fuel pellets, from agricultural waste - straw, corn and sunflower husks. However, the transportation of fuel pellets is quite energy consuming. The process of loading and unloading, transportation over long distances requires complex mechanized equipment. The use of a pneumatic conveyor for grain reloading will allow to provide high-quality transportation of fuel pellets. The aim of the article was to investigate the operation of the pneumatic conveyor for overloading fuel pellets, to determine the optimal indicators that affect the productivity of the pneumatic conveyor. Since fuel pellets, as raw materials, are structurally similar to cereals, a study of the pneumatic grain conveyor PTZ-25 was conducted. The dependence of the productivity of the pneumatic conveyor on the lifting height h, m and the length of the pipelines L, m was obtained. The obtained results showed that by reducing the length of the pipelines by four times and the lifting height by half, the productivity of the pneumatic conveyor will increase by 1.15 times. Key words: fuel pellets, pneumatic conveyor, productivity

Study of the significance of the ph of the substrate of the biogas installation during treating it with a low-frequency electromagnetic field

The article considers the issue of studying the value of pH, substrate in the process of methane fermentation in the mesophilic regime and the influence of the electromagnetic field of industrial frequency. The aim is to investigate the influence of electromagnetic fields on the pH value of the substrate during fermentation. Different types of microorganisms are involved in the process of methanogenesis, and the decisive role in it is played by methane-forming archaea, which are most sensitive to pH and should be in the range of 6.5 - 8. Therefore, it is necessary to check the effect of low frequency electromagnetic field on substrate pH. The study was performed for 25 days on two substrates, one of which was exposed to a low-frequency electromagnetic field with an electromagnetic induction of 3.5 mT. The research results show that the pH value of the substrate exposed to the electromagnetic field during the methane fermentation process was within acceptable limits, and the second substrate decreased, that is, it was acidified. Key words: methane fermentation, substrate, pH value, electromagnetic field

Filippova Automated planning of graduality assembly

Modern industrial production requires the improvement of assembly processes, and thus increase the level of automated intelligent sequence planning. Therefore, researches in the field of automation of the sequence of assembly of products in industries are relevant at this time. In today's world there is a need to develop complex, accurate products. Problems are created in industries due to the reduction of the life cycle of products. There is a need to study the problem of assembly planning to achieve the goal of practical implementation and standardization of assembly plans. Creating graphs of the addition process is one of the problems. The assembly planning system can reduce human intervention in the process and reduce computational effort. The finished assembly contains many components that can be assembled using many sequences. A review of the methods from the literature showed that although these methods increase the automation level, they still cannot be applied to actual production because they do not take into account the experience and knowledge that can play a major role in planning and are of great value. Assembly planning, relationship charts, priority charts. Improving the assembly planning system to create a communication schedule and an assembly priority schedule was proposed. The advanced system will be used to generate possible assembly sequences with subassembly identification. A system has been developed to create alternative possible assembly sequences that can be used by component part / product designers in the early stages. A system capable of generating assembly sequences for simultaneous assembly of multiple parts has been proposed. Conclusions and work results can be applied used and improved for more productive product development by designers in the early stages and faster assembly of products in enterprises. The paper did not consider practical limitations (gravity) and irreversible assembly operations, such as permanent fastening, welding etc. Кey words: assembly, blocking graph, relation graph, sequence

Development of technological scheme of microwave - units for grain drying

In the agriculture of Ukraine, a variety of drying installations are used, the design of which should ensure uniform heating and drying of grain, while at the same time allowing to control the temperature and humidity in the grain mass. The choice of an appropriate dryer can significantly improve the quality of dried grain, increase production profitability, increase production, reduce drying costs, and reduce energy costs. Currently, the most common drying method is convective, the disadvantages of existing convective grain dryers are low efficiency, low specific moisture removal, uneven drying, high costs of the drying agent, high energy consumption. The purpose of the study is to develop a drying plant designed for high throughput. The use of grain drying technology using microwave electromagnetic fields provides a number of significant advantages over conventional dryers that use only a thermal agent. Grain drying technology using microwave electromagnetic fields can be used in combined dryers. The technological scheme of the drying installation is developed, which is based on the principle of microwave heating, which allows to intensify the external and internal transfer during drying. In the developed scheme the drying process takes place in three working zones. In the first zone, heating is carried out by irradiation with an electromagnetic field in the microwave range of seeds to a certain temperature, the second - the aging of the seeds, where moisture is released in the inter-grain space. In the third zone, the layer is blown by air flow with the organization of fluidization. The main design and mode parameters using the software environment "Flowvision" are determined. Key words: grain, microwave oven, dryers, installation, electromagnetic field

Development of technological line for obtaining flax trust

One of the most effective ways to intensify heat transfer when blowing surfaces with air is jet blowing. High intensity of transfer processes during jetting, relatively low energy costs for its implementation, simplicity and flexibility of control of this process have led to its widespread use in various fields. Mathematical modeling of heat transfer regularities in systems of impact jets is significantly complicated due to the three-dimensional nature of the flue-channel flow near the surfaces of complex shape. Therefore, it is advisable to use experimental research methods. The purpose of this study is to justify the use of the method of regular thermal regime to determine the average heat transfer coefficient during jet cooling of the surface. Regular mode of cooling (heating) of bodies is characterized by the fact that the relative rate of change of excess temperature for all points of the body remains constant. Since the thermal model was made of a highly thermally conductive duralumin alloy, the condition Bi <0.1 was met, when the average temperatures on the surface and volume will be the same. Therefore, the experiments recorded the readings of only one thermocouple. To compare the results of this experimental study with the results of other authors, cases of blowing a smooth concave surface with single - and three - row jet systems were chosen. The first case was studied in [3,4], the second - in [5]. The results of the performed test experiments agree satisfactorily with the data of these works, which were obtained both by the method of regular mode [5] and other methods of recording heat fluxes ([3] - passive heat flux sensor; [4] - electrocalorimetry). The difference between the average heat transfer coefficients and the known literature data does not exceed ±7..12%, which indicates a sufficient probability of the results obtained in this work, and the possibility of using the method of regular thermal regime in the study of jet cooling of complex bodies. Key words: heat exchange, jet system, cooling, concave surface

Methodology of system analysis for research of energy efficiency problems in Ukraine

The results of the research on the application of a systematic approach to solving energy efficiency problems in Ukraine are presented. The reasons for restraining the level of energy efficiency are highlighted, among which are the hollowing: ineffective policy of incentives to reduce energy consumption; lack of investments and conditions for their attraction; inefficient tariff and price policy in the energy sector of the economy, non-compliance with regulations, programs of various levels and measures. The need to increase the level of energy efficiency in Ukraine is substantiated and a system analysis is proposed to solve this problem. The methodology of systems analysis is implemented using a systems approach, in particular, to the interpretation of the process of energy efficiency development as an open, nonlinear, complex system. As an element of systems analysis, the study uses a multilevel approach, which provides an opportunity to consider the object of study at different hierarchical levels: the international community, state, industry, region and individual. It is noted that in order to successfully develop the progress of energy efficiency in Ukraine, it is necessary to take into account global trends and recent large-scale changes in this area. Examples of progress realization at the state level are given, in particular, implementation of a large number of legal acts, a number of stimulating measures for energy saving, etc. The importance of the sectoral level to increase energy efficiency in Ukraine is indicated. The importance of energy efficiency potential at the regional level is emphasized, which can give a significant boost to its entire economy and significantly improve the lives of the population. The importance of optimizing the process of energy efficiency at the level of various institutions is presented; as one of the options for solving this problem, it is proposed to popularize its benefits both among the population and the individual. The multilevel approach to energy efficiency in Ukraine proposed in the study presupposes an integrated combination of efforts at different levels and a synergistic effect of solving the problem. Key words: energy efficiency, system, multilevel approach

Assessment of humidity regime of enclosing structures with a ball of insulation on the example of a training housing building in NULES of Ukraine

When assessing the thermal condition of the building and the parameters of the microclimate of the premises, the main factors influencing its thermal inertia were identified and taken into account. An assessment of the influence of the resistance of enclosing structures on the efficiency of the heating system, taking into account the influence of external and internal climatic parameters in the dynamic mode. It is shown that the time factor and depth of regulation, as well as the outdoor air temperature are important factors. Researches are carried out and the expediency of introduction of a duty mode of heating of buildings of HIGH SCHOOLS is estimated. The given algorithm of control of process of heat release (especially in the presence of a point of "breaking" - average (them) on the schedule) in addition increases accuracy of the decisions of the specified problems and reduces a temperature deviation by 4 ÷ 6 ° C in comparison with usual ("linear") dependence that allows to correct more precisely release of the heat carrier in system of heating of a structure at introduction of a standby mode. It was found that it took about 6.5 hours to achieve normalized air temperature and space heating in the forced (after a long stay on duty). It is shown that the heat consumption of the system in such conditions of its operation compared to the nominal mode increased by 25% (taking into account the limit value of the specific allowance from table H1 DBN B.2.5-67: 2013 "Heating, ventilation and air conditioning"), but for the entire period the action of the standby mode savings amounted to about 6-8% of energy consumed. Taking into account the design of the outer walls of the object of study, the temperature graph of the heating system was adjusted taking into account the value of the internal heat capacity of the building when implementing on-duty heating, which, according to preliminary estimates, will: improve comfort in the room; to reduce heating costs of the educational and administrative building of NULES of Ukraine by 10-12% for the heating period. Key words: enclosing structure, humidity conditions, dew point, partial pressure, water vapor

Analysis of the results of the influence of electric pulse treatment on purulent waste

High standards of sanitary and epidemiological safety at large pig-feeding complexes are one of the prerequisites for the production of high-quality pork. Livestock complexes are a source of accumulation of a large amount of manure runoff. Now there is a large tendency of environmental destruction and irreversible loss of natural resources due to pollution by waste from livestock enterprises. The use of new technologies for treating wastewater from food enterprises, industrial, livestock breeding is an urgent problem. The use of accelerated composting of the dewatered part of the effluent is one of the ways to increase the efficiency of using waste from pig farms. For this, scientists have developed a standard series of installations that ensure the conversion of waste into high-quality organic fertilizer, however, the issue of further use of the liquid part of the waste has not been fully worked out. That is why the use of the latest wastewater treatment technologies from industrial enterprises, food and agriculture is an urgent problem. One of the promising ways to improve treatment technologies for organic pollution is the use of cavitation phenomena and electrohydraulic shock in the aquatic environment. Analysis of existing wastewater treatment technologies shows that today environmentally friendly methods are being intensively developed, which are an alternative to chlorination and other chemicals. In recent years, the development and research of the operation of electro-pulse methods for disinfecting liquids, based on the creation of a high-voltage discharge in a liquid, the so-called electrohydraulic effect, have been actively pursued. Taking into account the long-term studies of the processes occurring during the electrohydraulic shock, the implementation of this method has not gone beyond the bench tests and is at the development stages. To study the effect of electrohydraulic treatment on chemical transformations of organic substances and disinfection, an experimental electric pulse installation has been developed. Waste waters of livestock complexes are characterized by organic and mineral pollution, they can have a different composition, which makes it impossible to determine the individual components of pollution. Therefore, it became necessary to find such indicators that would characterize certain properties of water without special identification of individual substances. To assess the efficiency of the electric pulse treatment of manure runoff, the BOD indicator was chosen - biological oxygen consumption and dry residue. Key words: slurry, pig feeding complex, electric pulse treatment, biological oxygen consumption

Optimization of the heat release regulation system

Heat supply regulation should ensure high energy efficiency of district heating systems (DHS) in general, reducing the specific indicators of heat production and release and maintaining the normalized thermal regime of the premises with any changes in outdoor temperature, insolation, infiltration and heat. Usually the processes of central regulation of DHS at heat sources and heat consumers are considered separately: not only technically but also organizationally. In this regard, the proposal for joint consideration of central and local regulation of heat supply is relevant and useful. The proposed solutions can increase the efficiency of existing DHS at the stage of transition to modern options for their implementation, in which heat control units are located at the entrance to individual apartments, and thus, the degree of regulation of DHS as close as possible to autonomous heating systems. The purpose of the study is to comprehensively consider the impact of individual stages of heat supply on the overall efficiency of DHS. The most common in domestic DHS is a method of high-quality central control of heat supply by changing the temperature of the coolant in the pipelines of thermal networks at the outlet of heat sources. However, this method has a significant disadvantage - it is inefficient regulation during the period of cutting the temperature schedule with a joint load on heating and hot water. Working during this period leads to significant overheating in premises and unproductive heat loss. Unproductive heat losses because of inadequate regulation when lowering the heat release schedule reach up to 18% of the heat potential of the fuel used. The introduction of a combined quantitative and qualitative regulation is proposed, in which, up to the cutoff temperature of the temperature schedule, the heat release is controlled by changing the temperature of the coolant, and after the cutoff, the transition to quantitative central regulation is carried out. Practical recommendations for the implementation of such regulation have been developed. Combined central regulation ensures the possibility of providing hot water supply services throughout the entire heating period, avoids hydraulic and thermal deregulation of systems and ensures optimal conditions for the operation of heat generators, reduced energy consumption and a significant increase in the overall efficiency of the DHS. Key words: heat supply, centralized systems, energy saving, efficiency, heat load regulation