Release:2018, Vol. 4. №4
About the authors:Vadim V. Burtsev, Cand. Sci. (Tech.), Associate Professor, Department of Heat and Gas Supply and Ventilation, Novosibirsk State University of Architecture and Civil Engineering; email@example.com
When designing single-pipe heating systems in multi-storey buildings, constructors face the problem of reducing the hydraulic resistance of the most stressed (in thermal terms) risers of the system. Solving it requires applying the division of such risers into zones along the vertical. At the same time, it becomes urgent to find the criterion for their breakdown, in which the authors proposed the maximum permissible thermal load of the riser.
This article provides the calculation of the resistance characteristic of the riser of a single-pipe heating system with the upper wiring and the radiators nodes often used in the practice of heating multi-storey buildings. The results are conveniently presented for computer calculation for the following initial conditions: nodes with a displaced radiator bypass, equipped with a thermostatic valves on the feeder, and on the return piping with shut-off valves; water-supply and gas-supply steel ordinary pipes; the nominal diameters of the radiator connections, the riser, and the radiator bypass are 15 mm; in the radiator units of larger diameter, the radiator bypass is one diameter smaller; heating devices is bimetallic sectional radiators.
Furthermore, the authors found correlation between the maximum permissible riser pressure losses for the project and the maximum permissible heat load of the riser, the exceeding of which requires its zoning. The calculation results are presented in the form of graphs of the function of the maximum permissible heat load of the riser from the pressure loss limit in it and the number of floors served by the riser.
The analysis of the calculations results allowed drawing the following conclusions: the larger the number of storeys of a building, the stronger the increase in the heat load of the riser will affect the growth of pressure losses in it; when deciding on the breakdown of risers of multi-storey buildings into zones, it is recommended to take the values of the maximum permissible thermal loads corresponding to the limit for the pressure loss in the risers of the project not exceeding 7 mH2O.