Optimization of the Parameters of the Heat Network Under a Reduced Temperature Schedule
Journal Title: Вентиляція, освітлення та теплогазопостачання - Year 2018, Vol 27, Issue
Abstract
The economic and environmental problems of Ukraine lead to decrease the water temperature in heat supply systems. Increasing the cost of fuel made it inappropriate to schedule temperature 95/70. To switch to a lower temperature schedule, at first it is necessary to ensure the automation of the regulation of individual heat points. Only after that it is possible to use reduced temperature schedules. This is confirmed by the successful experience of countries where central heating is widely used: Denmark, Germany, Finland, Sweden, Holland, etc. Modernization of the heat supply systems of Ukraine should go through transition to independent heating systems with qualitative and quantitative regulation, after which the temperature schedule can be reduced to appropriate values. A numerical study of the optimal temperature and water flow in the heat network depending on the design and operating parameters has been carried out. In addition, the results of field studies of the heating characteristics of residential buildings and administrative buildings, the heat supply of which is carried out from two big sources of Kharkov, were used. The entropy production in the heat supply system is numerically determined depending on the design and operating parameters. As a result of the computational experiment, when using entropy production as an optimization criterion, the parameters of the reduced temperature schedule of the heat supply system for the conditions of Kharkiv were determined and substantiated. The results of the numerical study show that the parameters of the heat network at maximum heat load and outdoor air temperature (-25 °C) are as follows: the temperature of the supply network water is 76.7 °C; heat carrier flow rate is 5.7 kg/s, velocity is 0.73 m/s, specific pressure loss is 85.3 Pa/m, specific consumption of electric power to transport the heat carrier is 0.81 W/m, specific heat loss is 33.8 W/m
Authors and Affiliations
I. O. Redko, А. O. Redko, A. Pryimak, O. F. Redko
Keywords
Related Articles
- EP ID EP556035
- DOI -
- Views 80
- Downloads 0
Simulation of Radiation Parameters Between Surfaces of Different Positions Using Point Calculation
One of the components of thermal comfort for a person in a room is the amount of radiant heat perceived by him, which depends on the nature and amount of radiant heat exchange between the surfaces of the enclosing struct...
Field Studies оf the "Cooling Effect" оf Vertical Greening оf Buildings
The aim of the work was to carry out field studies of the "cooling effect" of vertical greening of buildings and to compare the results with the "cooling effect" of the vegetation layer of "green roofs". The field studie...
Heat exchange influence of modified coolant triethanolamine fatty acid esters
Experimental and analytical studies telpofizicheskih properties of aqueous solutions of triethanolamine fatty acid esters. The effect of changes in the thermal properties of the heat. Increase of the kinematic viscosity,...
A Method for the Analysis of Isotherms, Surface Fractal Dimension and Dynamic Chaos of Moisture Exchange in Colloidal Capillary-Porous Museum Exhibits at Changeable Microclimate Conditions
On the basis of sorption-desorption isotherms in colloidal capillary-porous bodies (CCPT), their surface fractal dimension was calculated and its spatial-temporal changes were investigated. The physic-chemical and rheolo...
Analysis And Calculations Of Exergy Efficiency Of Speed Water-Water Heat Exchangers For Heat-Water Supply
Exergy efficiency is the most precise and correct characteristic of effectiveness of thermodynamic systems. A procedure for calculating the exergy efficiency (EE) for both individual elements of heat exchangers and for t...