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 74
- 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...
Assessment of Domestic Waste Water Potential for In-House Heat Pump Systems
A preliminary assessment of the possibilities of utilizing domestic waste water as a low-temperature source for a heat pump is made in the paper. Based on energy balance and heat transfer equations and analysis of thermo...
Numerical Solution of Problems of Single-Phase Non-Isothermal Filtration
Creating a geothermal circulation system requires predictable assessment of its efficiency. It is important in this process to research heat and mass transfer processes in an underground reservoir by a numerical method....
Features of Using the Regulatory Method "Thermal Calculation of Boiler Units" for Firetube Boilers
In recent years, the practice of using fire-tube and fire-fighting water-heating boilers in the replacement of service water heating boilers in boiler-houses has become commonplace in the district heating systems of the...
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...