THE ANALYSIS OF WATER SPEED INFLUENCE IN HOT-WATER DISTRIBUTION SYSTEM ON THE AMOUNT OF HEAT LOSS

One of the main tasks around the world is to reduce energy consumption with constant consumer comfort. The hot water supply system uses a significant part of thermal energy and requires no less attention than the heating or ventilation system. The amount of heat loss from hot water distribution systems is of great importance for the energy consumption of buildings. In winter, part of this heat is used for space heating, in summer they are unused and is considered as lost heat. For this reason, this paper considers the influence of water velocity in the pipe, pipe size, and water temperature on the total heat losses in the insulated hot-water distribution system. The data are presented in tabular and graphical form. A graph of the dependence of the amount of heat loss on the temperature and velocity of hot water is obtained.

EFFICIENCY OF THERMAL ENERGY GENERATION BY COGENERATION PLANTS DUE TO THE MAXIMUM USE OF HEAT

ignificant heat losses in centralized heating and hot water supply systems during the transportation of heat carriers lead to the need for decentralization of heat generating installations. It is shown that steam and gas installations for combined heat and power generation deserve the greatest attention. The ways of increasing the efficiency of cogeneration plants of various capacities based on CCGT by utilizing the heat of the heating system by installing recuperative heat exchangers on the return lines of the heating system after heating devices that are connected to the hot water supply network are substantiated, which makes it possible to reduce heat losses to the environment. The proposed system of rational interaction of the power plant with the heating and hot water supply system, which allows increasing the thermal efficiency of the cogeneration plant by 2%, which corresponds to a fuel saving of 3% due to the more complete use of the thermal energy of steam, which is sent as a selection for district heating. This article discusses solutions aimed at increasing the efficiency of heat generation by cogeneration plants by maximizing the use of heat from the exhaust steam of turbines.

Energy Saving and Economic Evaluations of Exhaust Waste Heat Recovery Hot Water Supply System for Resort

The objective of this study is to investigate the energy savings and economics of the hot water supply system for the luxury resort. The hot water was generated using the waste heat from the exhaust gas heat (EGH) of internal combustion engine (ICE) installed at the luxury resort. The capacity and characteristics of waste heat source, flow demand and supply system of hot water were surveyed, and data is collected from the real system. The new heat exchanger system which utilizes the EGH to produce the hot water is designed considering the dew point temperature and the back pressure of exhaust gas system. The results show that the proposed system could supply hot water at a temperature of 55 °C corresponding to the present resort demand of 6 m3/h using EGH of ICE at 20% load. The proposed system could achieve the saving of 400 L/day in diesel oil (DO) fuel consumption and the payback time of new system could be evaluated as 9 months. The proposed system could produce hot water of 14 m3/h at 25% of engine load and 29 m3/h at full engine load which are sufficient to satisfy the regular and maximum hot water demand of resort. The presented results show the capability of the proposed system to satisfy the current hot water demand of resort and suggest the larger potential to save energy by recovering EGH of ICE. The novelty of the present work involves detailed methodology to design heat exchangers and evaluate system economics for hot water supply system based on EGH of ICE.

SOLID HOUSEHOLD WASTE DISPOSAL BY DOUBLE STAGE BURNING ON WALKING BEAM AND IN THE BUBBLED MELT

State of the problem of solid waste disposal at landfills has been analyzed. A combined method of two stages of solid waste incineration during the heating season has been proposed. The results of calculations of thermal balances of evaporation processes, burning on a movable bottom and in a bubbled melt, heating of air in the recuperator, heating of water in the contact heat exchanger, boiler and in the hot water supply system has been presented. It is shown that the elimination of the source of pollution in the form of solid waste in a two-stage method of incineration: on a walking step and then in a bubbled melt — makes it possible to get rid of secondary solid waste generated by traditional incineration. As a result of melting in the bubbled melt gases are formed, which contain the products of combustion and decomposition of solid waste and slag consisting of silicates and metal oxides. Bibl. 10, Fig. 3, Table 1.

Piston compressor cooling system with a pulsed flow of coolant with subsequent use of heat in the hot water supply system

Цель. Большинство известных компрессоров используют механический привод от электродвигателя для достижения своей цели – перекачки необходимого потребителю количества сжатого воздуха. Во время работы любого компрессора прямого вытеснения выделяется большое количество тепла, которое вырабатывается как за счет трения движущихся частей блока, так и при сжатии воздуха.Метод. Предложена система охлаждения поршневого компрессора с импульсным потоком теплоносителя с последующим использованием тепла в системе ГВС при помощи пластинчатого теплообменника, зарекомендовавшего себя своей компактностью и эффективностью.Результат. С целью более глубокого отбора тепла в качестве типа движения нагреваемой линии был предложен импульсный поток, организованный при помощи ударного узла.Вывод. В качестве оценки системы было проведено сравнение с аналогичной системой со стационарным потоком, как по техническим параметрам (температура рубашки компрессора t руб. ; температура воздуха в ресивере tвозд. ; средняя тепловая мощность N ср. ; коэффициент теплопередачи K ; объём воздуха, перекачиваемый за 1 цикл Vвозд. ) так и по экономическим параметрам (время окупаемости установки по сравнению с аналогичной установкой со стационарным потоком Tок ).

Development of the Energy Circuits of Development of Contour Regulation of the Supply of Hot Water for Buildings With Variable Flow

The hot water supply system is one of the important components of the water supply and drainage system of high-rise civil buildings. With the development of the national economy and the improvement of people’s living standards, people’s requirements for popularizing hot water supply and improving hot water supply technology are becoming more and more urgent. In the process of hot water supply, the flow pressure of the pipeline is increased, and the purpose of hot water supply in high-rise buildings is achieved. The experiment analyzes the effect of the pressure ratio on the pipeline in front of the accumulator and the impact valve on the flow of coolant through the check valve. First, through the periodic opening and closing of the shock valve, the pressure continues to rise and fall, and the spring hose exhibits periodic pulsation. The effects of different pressure ratios on pipeline pressure and flow rate are studied, and the data of simulation calculation and actual measurement are analyzed through experiments. The research results have practical significance for improving the water supply efficiency of the hot water supply system of high-rise buildings.

Upgrading the hot water supply system as a way to save energy

The efficiency of works on replacement of steel pipelines of hot water supply of Kazan with pipes from polymer materials was considered. Due to the high corrosive activity of water, the service life of hot water pipelines does not exceed 8-10 years. To improve the reliability and quality of the supply of hot water to consumers, the possibility of modernizing hot water supply networks using pipelines made of polymer materials is being considered. The problem of physical wear of heat supply networks is disclosed; analysis of polymer pipelines use for energy saving purposes is carried out. Thermal energy savings are calculated after the modernization of heating networks. The costs, savings and payback period of the energy-saving measures are determined.

Estimation of Solar Hot Water System Operation for a Residential Building

Solar hot water supply systems can provide a significant part of the thermal energy needed in the residential sector. The use of solar hot water supply systems can reduce the consumption of traditional energy sources and, consequently, reduce greenhouse gas emissions. The aim of this article is to assess the operation of the solar heating system operation to provide the needs of the hot water supply system of a residential building with thermal energy. The efficiency of a flat solar collector operating in a single-circuit thermosyphon system of solar heating of a residential building in Lviv has been established. The solar fraction of the hot water supply system of a residential building is determined depending on the volume of hot water consumed, in particular 50, 60, 70, 80, 90, 100 l/day. It is established that the lower the need for hot water, the greater the solar fraction of the solar hot water supply system. Thus, the average annual solar fraction of the solar hot water supply system with a daily consumption of 50 l/day is 0.77, and with a daily consumption of 100 l/day the solar fraction is 0.39. The average value of the solar fraction for the solar hot water supply systems of the studied house is 0.55.

Determination Of Thermal Parameters Of Solar Water Heating Collectors Using The “Dark” Testing Method

In the production of flat solar water heating collectors, thermal testing occupies a special place, the purpose of which is to determine their thermal characteristics experimentally. The corresponding approximation expressions are proposed for determining the coefficient of heat loss, inclined to the horizon at an angle of 300 for the average conditions of their operation in the hot water supply system