Сучасні проблеми холодильної техніки та технології (Modern problems of refrigeration technology and technology)

Постійне посилання зібрання

https://card-file.ontu.edu.ua/handle/123456789/3469

Переглянути

Перегляд Сучасні проблеми холодильної техніки та технології (Modern problems of refrigeration technology and technology) за Назва

Зараз показуємо 1 - 20 з 266
  • Документ
    30 років монреальського протоколу. Стратегії в сфері обігу озоноруйнуючих холодоагентів
    (2017) Возний, В. Ф.
    2017 р. – рік 30-тиріччя Монреальського протоколу про речовини, що руйнують Озоновий шар Землі. МП є правонаступником Віденської конвенції від 22 березня 1985 р. Вступив в дію МП з 01 січня 1989 року і на даний час є практично єдиною угодою світового співтовариства, яку підписали 203 країни світу, графік виконання вимог якої успішно виконується практично в усіх країн світу.
  • Документ
    Analysis of the possibilities of a solar air conditioning system
    (2021) Ovchinnikov, M.; Zhykharieva, N. V.
  • Документ
    Design of periodic operation ammonia–water absorption refrigeration units in atmospheric water generation system
    (2017) Ozolin, N. E.; Titlov, A. S.
    It is a common knowledge that one of the most valuable resources in the future of our planet is going to be fresh water, and the demand for water resources is already one of the main factors in global logistics of contemporary world, and this trend will only grow in the foreseeable future. One of the developments in water production technology is mechanical air dehumidification — condensation of water vapor on the surfaces with a temperature below the dew point. In this case, there are great prospects for the methods associated with the work of independent generators of cold — chillers that are guaranteed to provide the temperature below the dew point temperature. A necessary condition for operation of compression refrigeration machine is the availability of electrical energy. At the same time, the majority of countries facing water scarcity are limited in energy resources, too. Often the readily available source of energy in there is the sun. In this regard there have been developed original schemes of absorption water-ammonia refrigeration units of periodic operation (AWRU PO) based on solar collectors, which differ with autonomy and independence from the sources of electrical energy, and unlike heat-analogues (steam jet and lithiumbromide absorption) can be operated with air cooling of their heat-dissipating elements.
  • Документ
    Development of universal absorption refrigeration devices for operation in a wide range of ambient temperatures
    (2017) Selivanov, A. P.
    In the recent years, greater weight in the structure of agricultural production in Ukraine belongs to individual farms and farmers. In these farms arise the problems of forming a regular economical budget, including a major problem in the preservation of the grown crops for three to six months in commercial quantities and at minimal energy costs. However, the acknowledged fact in world practice is the loss of most of the harvest of agricultural products in the absence of adequate refrigeration storage. Currently, the bulk of Ukrainian harvested fruits and vegetables is traditionally stored in the basements, where during the warm seasons (August—November, April—May) the required temperatures (5…12C) often cannot be maintained. To ensure the required regimes of storage, the market of household and commercial refrigeration equipment for small wholesale manufacturers offers national and imported demountable (panel) cold storages of volumes 3...9 m3, equipped with compression refrigeration machines. In modern conditions in rural Ukraine, operation of such cells is hampered by lengthy power outages and by poor quality electricity incoming (range of fluctuation of voltage is 160—250 V). The current situation makes appeal to heat-powered pumpless absorption refrigeration units (ARU).
  • Документ
  • Документ
  • Документ
    Development of thermopressor systems for air intercooling in multistage compressors
    (2021) Kobalava, H.; Konovalov, D.; Shkvorchenko, V.
  • Документ
    Efficiency evaluation of domestic solar assisted ground-source heat pump system for southern Ukrainian region
    (2017) Ostapenko, O.; Yakovleva, O.; Khmelniuk, M.
    With raising energy prices and more restricted environment regulations, the rational use of energy resources in household sector becomes more important. It is directly linked to increasing energy needs of humanity and the simultaneous depletion of traditional non-renewable energy resources in the world as a whole and in individual regions. Heat pumps are widely used in the chemical and food industries, housing and communal services. The use of heat pumps allows reducing greenhouse gas and carcinogenic substances emissions and, thus reducing human impact on the environment. The heat pump performance is based with following factors: the temperature of heat source, schematic diagram of the heat pump, climate conditions of the region, working fluids of heat pump (refrigerants and intermediate coolants), heat pump elements (type of compressors, heat exchangers, control systems).
  • Документ
    Efficiency of refrigerating ejector systems for condensation of liquid hydrocarbons of oil products
    (2017) Butovskyi, I. D.; Kogut, V. E.
    The simple traditional methods of prevention of losses of oil product having the low cost (the respiratory valve, gas-leveling system) are insufficiently effective. The known basic approaches of storage of oil products by introduction of superficially active agents. However, in practice these ways have not found broad application. Essential source of economy of oil resources - elimination of losses at their production, processing, transportation and storage. By estimates of specialists, only at the expense of it it is possible to receive up to 20% of all economy of fuel and energy resources. Damage caused by these losses consists not only in reduction of fuel resources and cost of the lost products, but also in negative ecological effects which are result of environmental pollution by oil products. Therefore, fight against losses of oil products gives not only economic effect, but also is vital for ensuring conservation.
  • Документ
  • Документ
    Mathematical model of vapour condensation in the contact heat exchanger
    (2017) Butovskyi, I. D.
    Authors offer use condensation and cooling system based on the contact ejector heat exchanger. Such system allows to exclude completely losses at evaporation of hydrocarbons of oil products, and as a result, to exclude the environmental pollution connected with "small" breath of fuel tanks. Prospects of use of such systems are caused by the possibility of their placement in shallow regions, enough remote from large settlements that ensures additional safety of operation of reservoir parks, gas station.
  • Документ
    Modeling of thermal modes of the reflux condenser of the absorption refrigeration unit
    (2017) Kholodkov, A. O.; Titlov, A. S.
    Currently, developers of modern refrigeration equipment, in accordance with the plans of the UN, are moving to natural refrigerants (hydrocarbons, carbon dioxide and ammonia) that do not have an adverse technological impact on the ecosystem of the planet. In domestic refrigeration technology, one of the options is absorption refrigeration units, the working body of which is an aqueous ammonia mixture with the hydrogen addition. Having a number of unique advantages over compression analogs, absorption systems are characterized by lower energy characteristics.
  • Документ
  • Документ
  • Документ
    Operational efficiency improvements for refrigeration systems during summer period
    (2017) Nesterov, P. S.; Buyadgie, O. D.; Khmelniuk, M. G.; Yakovleva, O. Y.
    Nowadays Refrigeration Systems (RS) consume large amounts of electricity. That’s why RS pay significantly to the running costs of businesses with substantial cooling requirements. Improving simple operational practices with minimum cost can contribute to reduction energy costs by 20% or even more. It becomes more important as a price is placed on greenhouse gas emission in future years and as energy prices rise. Its importance also relates to an increased focus on reducing fugitive emissions from industrial systems such as refrigerant gas. It leads to a peak load on energy capacity in the summer, and has a disastrous effect on climate change, which in own turn leads to an increase in the maximum summer temperatures and their duration for the season. The latter factor causes an increased demand for cold, but at the same time an inevitable increase in the condensation temperature. Often it is accompanied by a destabilization of the refrigeration machine performance, up to an extreme fall in cooling capacity. As a result, the economy and the environment suffer.
  • Документ
    Optimization and improvement of energy efficiency of refrigeration unit with the use of spraying pools
    (2021) Zhykharieva, N. V.; Kogut, V. E.; Dragnev, М.; Оstapenko, D.
  • Документ
    Radiative cooling method in the air conditioning system
    (2017) Tsoy, A. P.; Tsoy, D. A.
    In the modern world, refrigeration and air conditioning systems are rapidly developing industries with high energy consumption. In this regard, there is significant interest in improving energy efficiency.
  • Документ
  • Документ
    The search of energy–efficient operation mode of ammonia-water-absorption refrigeration machines
    (2017) Osadchuk, E. A.; Kirilov, V. Kh.; Mazurenko, S. Yu.
    A basic volume of the market of equipment for the separation of water from the air, in our times, falls on the systems, having in its composition compression refrigeration unit electrically-driven. At the same time, the use of compression unit is perspective only for the performance to 3-4 liters per hour. There is substantial growth of sizes of setting at more high performance. The necessary condition of work of compression refrigerating machines is the availability of electrical energy. At the same time, the overwhelming number of countries experiencing water shortages are limited in energy resources. The sun is the only source of energy that they have. Thus, the problem of obtaining water from atmospheric air is an actual scientific and practical task which didn’t find the decision up till now and most of the technical proposals remain on the level of patents.
  • Документ
    The cycle ensuring uninterrupted operation of the contact heat exchanger
    (2019) Kogut, V. O.; Bushmanov, V. M.; Khmelnyuk, M. G.; Zhikhareva, N. V.
    In this work, a method was proposed that can ensure almost uninterrupted operation of a device for trapping a pair of liquid fuels. The results are applicable in the fuel and energy field and can provide an improvement in the environmental situation.