scholarly journals Heat-exchange units with porous inserts

2019 ◽  
Vol 140 ◽  
pp. 05006 ◽  
Author(s):  
Oleg Stepanov ◽  
Boris Aksenov ◽  
Natalia Rydalina ◽  
Elena Antonova
Keyword(s):  
Heat Transfer ◽  
Heat Exchangers ◽  
Heat Supply ◽  
Analytical Data ◽  
Porous Metal ◽  
Hot Water ◽  
Porous Metals ◽  
Proposed Model ◽  
Heat Supply Systems ◽  
Supply Systems

Currently, porous metals are not used in heat supply systems. Usage of porous materials in heat exchangers increases the heat transfer intensity and makes the heat exchangers more compact. An experimental setup consisting of two circuits was developed in order to study the influence of porous metals on heat transfer intensity. In the first circuit the hot coolant is water, which flows through narrow tubes inside the porous metal. In the second circuit the cold coolant is freon. The purpose of the study is to obtain experimental confirmation of the hypothesis of an increase in the heat transfer intensity when using porous metals. To achieve this goal, experiments were carried out, which showed the increased heat transfer intensity. The standard methods for calculating heat exchangers cannot be applied in this case as the inner pores’ surface is unknown. A mathematical model was compiled allowing engineering calculations for the heat exchangers of this type. The hot water temperature inside the heat exchanger is determined analytically. The resulting equation allows us to determine the cooling degree of the first coolant, i.e. hot water. The obtained deviations between experimental and analytical data are within the acceptable limits, which indicates the reliability of the proposed model.

scholarly journals The use of porous metals in the design of heat exchangers to increase the intensity of heat exchange

2020 ◽  
Vol 178 ◽  
pp. 01026
Author(s):  
Natalia Rydalina ◽  
Oleg Stepanov ◽  
Elena Antonova
Keyword(s):  
Heat Exchanger ◽  
Heat Exchange ◽  
Heat Exchangers ◽  
Heat Supply ◽  
Analytical Form ◽  
Test Facility ◽  
Porous Metals ◽  
Heat Supply Systems ◽  
Set Up ◽  
Supply Systems

Heat exchangers are widely used in heat supply systems. To increase the efficiency of heat supply systems, heat exchangers with porous metals are proposed to design. There was a test facility set up to study new types of heat exchangers. The countercurrent flow of heat carriers was activated in those heat exchangers. Freon moved through the heat exchanger pores, and water moved through the inner tubes. It should be noted that the porous materials in the heat exchangers differed in the coefficient of porosity. To be compared, one of the heat exchangers did not contain any porous material. The first test cycle proved the feasibility of using porous metals in heat exchange equipment. Afterwards, a simplified mathematical model of the heat exchanger was compiled. Such an analytical form makes a solution convenient for engineering calculations. Numerical calculations based on this model were compared with the experimental data. Heat transfer intensity of materials with different porosity was compared.

Analysis of the ecological and economic efficiency of the boiler modernization project

2021 ◽  
Vol 27 (7) ◽  
pp. 94-102
Author(s):  
D. Bergen ◽  
Keyword(s):  
Economic Efficiency ◽  
Heat Supply ◽  
Negative Impact ◽  
Economic Effect ◽  
Boiler House ◽  
Hot Water ◽  
Anthropogenic Load ◽  
Ecological Effect ◽  
Heat Supply Systems ◽  
Supply Systems

The current set of problems in the field of heat power engineering has remained unresolved for many years. Ecological modernization of fixed assets of heat supply enterprises is defined as the main direction of ensuring the activities of regional heat supply systems in this article. The subject of the research is a set of theoretical, methodological and practical issues of the analysis of indicators of the ecological and economic efficiency of the boiler house modernization project. The purpose of the study is to analyze the ecological and economic efficiency of the project for the modernization of boiler houses to replace coal with more environmentally friendly fuels. The study has been carried out using a set of methods: comparative analysis, analysis of structure, financial analysis. The use of solid biofuels makes it possible to reduce the anthropogenic load from heat supply enterprises. The ecological effect consists in the reduction of total emissions into the atmosphere by 69 times or by 321 tons per year of the boiler house on bit fuel compared to a similar boiler house on coal. The economic effect for the boiler house lies in the possibility of saving on fees for the negative impact on the environment, depending on the fuel used. The calculations show that payments for negative impact on the environment have a small share in the cost of steam and hot water production by boiler houses. In this connection, this cannot become a motive for reducing the negative impact. It is necessary to establish standards for the negative impact and waste disposal at a minimum level in order to form a material interest among economic entities in reducing the anthropogenic load on the environment. The author has calculated the environmental and economic indicators of the project for the modernization of regional heat supply systems, based on the transition from using coal as the main fuel. This calculation can become the basis for the state program for the modernization of thermal energy

Regression Analysis in Energy Systems

2013 ◽  
Vol 740 ◽  
pp. 772-777 ◽  
Author(s):  
Roman Kuznetsov ◽  
Valeri Chipulis
Keyword(s):  
Regression Analysis ◽  
Data Processing ◽  
Heat Supply ◽  
Measuring Equipment ◽  
Analytical Data ◽  
Energy Systems ◽  
Power Engineering ◽  
Heat Power ◽  
Heat Supply Systems ◽  
Supply Systems

The methods are considered for analytical data processing by measurements in heat supply systems. These methods are oriented to the solution of practical problems in the heat-power engineering by using the information-analytical systems. The possibilities of regression analysis for effective heating control and diagnosis of the measuring equipment are shown.

scholarly journals RELEVANCE OF CONTAMINATION MODELS FOR DIAGNOSTICS OF PLATE HEAT EXCHANGERS

2020 ◽  
Vol 5 (10) ◽  
pp. 33-40
Author(s):  
Y. Elistratova ◽  
A. Seminenko ◽  
V. Minko
Keyword(s):  
Heat Exchange ◽  
Heat Exchangers ◽  
Heat Supply ◽  
Heating Surface ◽  
Actual Distribution ◽  
Plate Heat ◽  
Salt Deposition ◽  
Theoretical Approaches ◽  
Heat Supply Systems ◽  
Supply Systems

The article analyzes various theoretical approaches to describing the processes of formation of scale layers on the working surfaces of heat exchangers. The main tasks include analyzing existing models of contamination of heat exchange channels, determining the main mechanism of salt deposition on the heating surface of plate heat exchangers of heat supply systems, determining the main factors that determine the intensity of salt deposition on the working plate in accordance with the dynamics of heat and hydraulic processes in heat exchange channels formed by corrugated plates, as well as forming trends for further research. The article presents the main results of research devoted to the study of contamination processes on heating surfaces. Inaccuracies in the proposed approaches to describing the nature of the formation of salt deposition layers are identified. By generalizing existing approaches to the mathematical description of pollution processes, the main assumptions are revealed when describing the processes of salt deposition on working plates. A hypothesis is proposed about the influence of the location of channels relative to the inlet pipe on the uniformity of the flow distribution between parallel channels in the device. There is a fairly large gap between the existing computational methods for modeling pollution processes and the actual distribution of scale layers during the operation of heat exchange equipment of heat supply systems

scholarly journals MODERN METHODS FOR THE INTENSIFICATION OF SHELL AND TUBE HEAT EXCHANGERS IN HEAT SUPPLY SYSTEMS

2018 ◽  
Vol 8 (2) ◽  
pp. 130-140
Author(s):  
L.A. Kushchev ◽  
◽  
N.Yu. Nikulin ◽  
Yu.G. Ovsyannikov ◽  
A.I. Alifanova ◽  
...  
Keyword(s):  
Heat Exchangers ◽  
Heat Supply ◽  
Modern Methods ◽  
Shell And Tube ◽  
Heat Supply Systems ◽  
Supply Systems

scholarly journals INCREASING THE EFFICIENCY OF COMBINED PRODUCTION HEAT AND ELECTRICITY

2021 ◽  
Vol 7 (2(38)) ◽  
pp. 58-66
Author(s):  
Maxim Olegovich Maximov
Keyword(s):  
Gas Turbine ◽  
Heat Supply ◽  
Electric Energy ◽  
Hot Water ◽  
Heat Supply Systems ◽  
Lower Temperature ◽  
Generating Equipment ◽  
Steam Parameters ◽  
Technical Solutions ◽  
Supply Systems

The main directions of increasing the efficiency of combined production of electric and heat energy are considered, associated with the improvement of power generating equipment, regime and circuit changes in heat supply systems while ensuring heat load. For many years, centralized heat supply based on combined heat and power generation has been successfully developing in Russia, which is a very attractive energy and nature saving technology. Its use makes it possible to save about 20 million tons of fuel annually, which is about 14% of the total volume of fuel consumed in Russia for the needs of heat supply. More than 50% of electricity is generated at CHPPs in Russia, and the efficiency of fuel use at them reaches about 70–75%. Such areas include the use of steam and gas technologies (CCGT units and gas turbine superstructures of equipment of operating CHPPs) and GTU-CHPPs, increasing the initial steam parameters at CHPPs, superstructure of hot water boilers with gas turbine units, improvement and modernization of existing turbine equipment and CHPP schemes, as well as rejection of peak boilers in favor of peak boilers at CHPPs, transition to a lower temperature schedule and a change in the structure of heat supply systems. The main advantages of these areas and the problems associated with their implementation are presented. The conditions of possible and expedient application of some directions are considered. It is shown that, in many respects, the choice of certain technical solutions, despite the energy efficiency, is determined by the conditions of the regional heat and electric energy markets.

Experimental investigation and mathematical model of a heat exchanger with porous metal inserts

2020 ◽  
Vol 6 (2) ◽  
pp. 22-40
Author(s):  
Boris G. Aksenov ◽  
Oleg A. Stepanov ◽  
Natalia V. Rydalina
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Theoretical Data ◽  
Porous Metal ◽  
Porous Metals ◽  
Standard Methods ◽  
Porous Aluminum ◽  
The Status

When creating and manufacturing heat exchangers, one of the main tasks is to increase the efficiency of heat transfer. The use of porous metals in heat exchangers is one of the promising ways to increase the heat transfer intensity, which determines the relevance of the study. The paper provides an overview of the status of this issue on literary sources. The purpose of the work is to conduct an experimental study of a heat exchanger with porous materials, to compile a mathematical model that allows analytical calculations of such heat exchangers, to confirm the correctness of the compiled model experimentally. An experimental bench has been created to study a heat exchanger that uses porous aluminum. The hot fluid is warm water that flows through pipes passing through a porous metal. The cold coolant flowing through the pores is freon, which cools the water. A schematic diagram and description of the stand are presented. A test cycle has been conducted. A comparison of the heat transfer intensity for materials of different porosity is given. Using standard methods for calculating heat exchangers in this case is not possible due to the lack of standard methods for determining the area of the inner surface with pores. In the course of the work, the standard equation describing the cooling of a porous body was proposed to be supplemented by the function of distributed heat sources. As a result, we have obtained a mathematical model of the heat exchanger under consideration in a simplified form, which can be used in technical calculations. The calculation results by the obtained method are correlated with the data of experiments. Deviations of empirical and theoretical data are within acceptable limits. The results obtained make it possible to use porous metals in order to increase the heat transfer intensity in the manufacture of heat exchangers. This technique allows calculations with an unknown heat exchange surface area, taking into account the heat capacity and heat of phase transition, if any. According to the methodology, the article is experimental-theoretical. Experiments are being conducted on the created laboratory bench. In parallel, calculations are made according to the developed mathematical model. The results are compared. Conclusions are made of a theoretical and applied nature.

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