scholarly journals Modernization of electrical complex for producing thermal energy for an industrial enterprise

2021 ◽  
Vol 5 (1(61)) ◽  
pp. 25-32
Author(s):  
Yevheniia Chebotarova ◽  
Andrii Perekrest

The object of research is the electrical complex for the preparation of thermal energy at the enterprise. The electrotechnical complex is a heat supply unit that provides thermal energy to the building of the enterprise for the needs of heating, ventilation and hot water supply. One of the identified shortcomings of this facility is the overconsumption of energy resources for heating, caused by the lack of the ability to control consumption. Modernization of heat points and equipping them with automation means will provide quantitative and qualitative control of the heat carrier depending on the outside air temperature. In the course of the study, the method of statistical data analysis was used to analyze the heat load of buildings for heating, ventilation and hot water supply, and the distribution of heat loads by the temperature of the indoor air. Also, an improved discounted method for evaluating the effectiveness of investment projects was used when calculating economic indicators and a method for calculating heat consumption for heating according to aggregated indicators when determining energy consumption for heating. On the basis of the analysis of the heat load and a certain structure of its distribution according to the temperature of the internal air, it was found that more energy resources are consumed for heating. The largest consumer is defined as a building with an internal temperature Tin=16 °C. Calculations of the commercial attractiveness of the proposed technical solutions for buildings with an internal temperature Tin=18 °C have confirmed the feasibility of their implementation in terms of their payback, which does not exceed the period of 3.5 heated seasons. Thanks to the modernization of heat points and the introduction of automated monitoring and regulation systems, optimal heat energy consumption will be ensured depending on the ambient temperature. Unlike other similar studies, the feasibility of introducing automated systems is determined by an improved discounted method, which allows not only to take into account the change in the value of money in the future, but also the required minimum percentage of thermal energy savings to break even projects.

Author(s):  
Z. Sirkо ◽  
◽  
V. Korenda ◽  
I. Vyshnyakov ◽  
O. Protasov ◽  
...  

Heat pump - a device for transferring thermal energy from a source of low potential thermal energy to a consumer with a higher temperature. The thermodynamic cycle of a heat pump is similar to a refrigerating machine. Depending on the principle of operation, heat pumps are divided into compression and absorption. The most commonly used compression heat pumps. In recent years, numerous publications on the use of heat pump technology in heating and hot water supply facilities of various spheres - from individual homes to residential neighborhoods have appeared in various media. The authors of the publication have many years of experience in joint scientific and technical cooperation with leading technical universities and industrial organizations in the field of development and practical use of heat pump technology. The authors analyze the possibilities of introducing heat pumps at enterprises and organizations of the State Reserve System of Ukraine. It has been shown that the amount of expenses in comparison with central heating or operation of gas and electric boilers of similar power is several times smaller. It is noted that the implementation of heat pumps is a promising direction in the use of alternative energy sources to meet the heating, ventilation and hot water supply needs of buildings. The payback period from the introduction of heat pumps at enterprises is 4-9 years, depending on the location of the object and the type of source of low-temperature heat. The article meets the requirements of the State Tax Code of Ukraine and can be recommended for publication.


Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5531 ◽  
Author(s):  
Taro Mori ◽  
Yusuke Iwama ◽  
Hirofumi Hayama ◽  
Emad Mushtaha

Hot water supply is one of the leading consumers of energy in the building sector in cold climate areas. The use of woody biomass is effective in reducing CO2 emissions in hot-water supply systems. This report deals with a system that combines a wood pellet boiler (PB) and a heat pump system with CO2 (CO2HP) that is used in a facility for disabled people. The following research was conducted. The operation of a hybrid system combining a PB and CO2HPs was investigated. While operating the system, four specific operations were developed as countermeasures to save on costs and reduce system troubles while reducing CO2 emissions. The processes and results are introduced. Numerical simulations were carried out to optimize the operation. The hot water temperature, water volume, and hot water loads were simulated. The influence of the water volume ratio on the cost and primary energy consumption under the requirements for safe system operation was studied. The regional economic ripple effects (REREs) of this system were studied. The wood pellet boiler is not only a measure for reducing primary energy consumption but can also play an important role in a regional economy for sustainable development in countries that import energy resources such as Japan.


2011 ◽  
Vol 347-353 ◽  
pp. 587-590
Author(s):  
Qing Hai Luo ◽  
Zheng Zuo

This paper analyzes the energy consumption of hot water supply in buildings and the insurmountable shortcoming of low energy efficiency of conventional water heaters, and investigates the progress and problems of developing heat pump water heaters. It is pointed out that developing of heat pump water heaters is one of the efficient approaches to improve the energy efficiency of hot water supply.


2019 ◽  
Vol 10 (2) ◽  
pp. 79-91
Author(s):  
T. A Rafalskaya ◽  
A. R Mansurov ◽  
A. R Mansurova

The combined method of generating electric and heat energy at CHP plants has been and remains the most effective way of fuel saving both in housing and communal services and in industry. In Russia, historically, a qualitative method of regulation has been adopted, which consists in changing the temperature of the fluid depending on the change in the temperature of the outside air at a constant flow rate of the fluid. An analysis of the heat supply schemes of a number of Russian cities revealed that central quality regulation at heat sources has practically ceased everywhere. In modern methods of calculating the qualitative and quantitative regulation, the main load is heating, and the load of hot water is taken into account only by increasing the flow rate of network water and the variable modes of joint operation of heating and hot water systems are not calculated. Thus, at present, there are no methods for calculating the qualitative and quantitative regulation, allowing to fully taking into account the effect of the load of hot water on the operation of heating systems. Therefore, in modern conditions, the previously developed methods and technological methods of controlling the combined heat load are characterized by a decrease in efficiency, and, accordingly, the problem of their optimization arises. For different temperatures of outdoor air, the calculation of variable operating modes of the heat supply system was carried out, which showed that the existing schedules of qualitative and quantitative regulation cannot provide a comfortable temperature condition of the premises. Under the conditions of a connected supply of heat, simply adding up the flows of network water for heating and hot water supply fails to achieve optimal thermal conditions for the premises. Therefore, further improvement of the technology of the central qualitative and quantitative regulation of the heat load taking into account hot water supply is required.


2020 ◽  
Vol 212 ◽  
pp. 01011
Author(s):  
Vladimir Melnikov ◽  
Uladzimir Navaseltsau ◽  
Dzina Navaseltsava

Centralized hot water systems widely used in Russia and Belarus are characterized by a considerable length and branching which inevitably leads to increased heat losses and to an unstable hydraulic system. The operation of the domestic hot water system in the circulation mode can be characterized by several parameters; one of which is the specific ratio of the cost of thermal energy for heating a cubic meter of hot water. The parameter is often regulated by law in Russia; exceeding this parameter is considered as administrative violation. The aim of the research is to determine the design and actual costs of thermal energy for hot water supply (hot water heating) and their comparison, analysis of the data obtained. The methodology for determining the design and real costs of thermal energy for hot water supply was to study the operation of the hot water supply system of a residential 144-apartment 9-storey building. The research showed that the actual circulating flow rate is much less than the calculated circulating flow rate. The authors note that in order to optimize the standard for heating a cubic meter of water it is necessary to observe the calculated circulation modes. This will require stabilization of the hydraulic systems of both the external and internal networks which is a difficult but feasible task. The research results are supposed to be taken into account when setting up existing hot water supply systems.


2021 ◽  
Vol 937 (4) ◽  
pp. 042037
Author(s):  
Gregory Vasilyev ◽  
Victor Gornov ◽  
Marina Kolesova ◽  
Vitaliy Leskov ◽  
Victoria Silaeva ◽  
...  

Abstract Experimental studies of this article are aimed at solving the problem of reforming the housing and communal services of Russia through rational integration of non-traditional energy sources and secondary energy resources into the energy balance of buildings and structures. An important component of the work was the creation and development of industrial production of reliable competitive heat pump systems of a new generation, cogenerating heat energy and cold in an autonomous mode and providing energy savings of at least 50% due to the combined use of low-potential thermal energy of the soil, the atmospheric air and the exhaust air of ventilation systems for hot water supply and air conditioning systems of apartment buildings.


2018 ◽  
Vol 82 (1) ◽  
Author(s):  
Юрий Анатольевич Селихов ◽  
Виктор Алексеевич Коцаренко

Европейские страны демонстрируют высокие возможности простого преоб­разования солнечной энергии в тепловую энергию, которая может успешно использо­ваться для обеспечения различного рода технологических, отопительных и бытовых потребностей. Кроме того, ввод в эксплуатацию сол­нечных установок улучшает экологическую ситуацию района потребления тепловой энер­гии за счет снижения объемов выбросов загряз­няющих веществ, к которым относятся продукты сгорания органического топлива, используемого для производства тепловой энергии. В настоящее время в южных районах Украины уже используются солнечные установки для горячего водоснабжения и отопления. Однако, внедрение новых энергетических и экономически выгодных установок идет медленными темпами, что объясняется довольно высокими стоимостными показате­лями, как отечественных, так и зарубежных установок. Таким образом, на наш взгляд, является актуальной концепция создания новых солнечных установок, наиболее привлекательных для потенциаль­ного потребителя. Реализация данной кон­цепции возможна при таком варианте исполнения солнечных установок, когда затраты на выработку тепловой энергии с помощью этих установок будут ниже уровня суммарных затрат на получение тепловой энергии традиционными способами (в частности, в котельных установках). Однов­ременно с этим, срок окупаемости солнечных установок должен быть соизмерим с гарантийным сроком их эксплуатации. Для выполнения поставленных условий представ­ляется целесообразным разработка таких конструкций солнечных коллекторов, которые позволяли бы минимизировать затраты на их изготовление, монтаж и обслуживание. Это может достигаться за счет использования дешёвых отечественных материалов, выпуск которых гарантирован в достаточных объемах на протяжении длительного срока. Разработка, изготовление и внедрение двухконтурных солнечных установок позволило круглогодично эксплуатировать солнечный коллектор, но капитальные и эксплуатационные затраты при этом были  на таком уровне, что для полной окупаемости солнечной установки могло понадобиться более пяти лет, так как солнечные коллектора изготавливались из металла.  В рамках сформулированной задачи нами был разработан и изготовлен солнечный коллектор из полиэтиленовой пленки. Предлагается двухконтурная солнечная установка для горячего водоснабжения и отопления, у которой солнечные коллектора изготовлены из полиэтиленовой пленки. Такая установка разработана, изготовлена и запущена в эксплуатацию в одном южном регионе Украины. На установке были получены экспериментальные результаты работы установки в разных режимах в течение года. После обработки этих данных были получены обобщающие зависимости: плотности теплового потока от температуры теплоносителя в коллекторе, времени работы установки в течение светового дня и расхода теплоносителя; коэффициента полезного действия от плотности теплового потока; максимального коэффициента полезного действия от максимальной плотности теплового потока; количества теплоты при конвекции от скорости натекания ветрового потока от 1 до 6 м/с на внешнюю поверхность солнечного коллектора. Зависимости получены при разных объемных расходах V от 0,5 до 3,0 м3/ч теплоносителя. Максимальная погрешность проведенных расчетов не превышает 5 %.  European countries demonstrate high opportunities for simple conversion of solar energy into thermal energy, which can be successfully used to provide various types of technological, heating and domestic needs. In addition, the commissioning of salt plants improves the ecological situation in the area of consumption of thermal energy by reducing emissions of polluting substances, which include combustion products of organic fuel used for the production of thermal energy.  At present, solar installations for hot water supply and heating are already used in the southern regions of Ukraine. However, the introduction of new energy and economically advantageous plants is proceeding slowly, which is explained by rather high cost indices, both domestic and foreign installations.Thus, in our opinion, the concept of creating new solar installations that are most attractive to a potential consumer is relevant. Implementation of this concept is possible with such an option of solar installations, when the cost of generating thermal energy using these facilities will be lower than the total cost of obtaining thermal energy by traditional methods (in particular, in boiler plants). However, with this, the payback period of solar installations should be commensurate with the warranty period of their operation. To fulfill the set conditions it is advisable to develop such designs of solar collectors that would allow to minimize the costs of their manufacture, installation and maintenance. This can be achieved through the use of cheap domestic materials, the release of which is guaranteed in sufficient quantities over a long period. The development, production and implementation of dual-circuit solar installations allowed the solar collector to be operated year-round, but the capital and operating costs were at such a level that it would take more than five years to fully pay for the solar installation, since the solar collectors were made of metal. Within the framework of the formulated task, we developed and manufactured a solar collector made of polyethylene film. A double-circuit solar installation is proposed for hot water supply and heating, in which the solar collectors are made of polyethylene film. Such an installation is designed, manufactured and commissioned in one southern region of Ukraine. Experimental results of the installation in different modes during the year were obtained at the plant. After processing of these data, generalizing dependencies were obtained: the heat flux density from the coolant temperature in the collector, the operating time of the installation during the daylight and the flow of the coolant; coefficient of efficiency from the density of heat flow; the maximum efficiency from the maximum heat flux density; the amount of heat in convection from the rate of leakage of the wind flow from 1 to 6 m / s on the outer surface of the solar collector. Dependencies were obtained at different volumetric flows V from 0.5 to 3.0 m3 / h of the heat carrier. The maximum error in the calculations does not exceed 5%.


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