The method of adjustment of heat supply systems with the multistage temperature control at pumping stations

Melentiev Energy Systems Institute of the Siberian Branch of the Russian Academy of Sciences, 664033, Lermontova str., 130, Irkutsk, Russia

^* Corresponding author: tslava@isem.irk.ru

Abstract

The lowering of the temperature graph in the lower-level heat networks is often carried out by a mixture of coolant from the return pipeline at mixing pumping stations in order to maintain the set temperature of the mixed water. In this case, part of the heat carrier is not returned to the source of thermal energy, but it circulates in the circuits from the mixing station to the lower consumption nodes. The presence of such circulation flows leads to the absence of a stabilizing moment of the temperature field when it is calculated by traditional methods, as well as to the “looping” of the computational process and the impossibility of obtaining a solution. In work to overcome these problems, a new computational scheme for commissioning calculation is proposed, which is based on: (a) decomposing the calculation of the thermal-hydraulic regime into calculations of the hydraulic and temperature conditions; (b) using the conditional regulator of the ratio of the mixing station’s output costs in calculating the hydraulic regime; (c) fixing the temperature at the station’s output when calculating the temperature regime; (d) iterative calculation with correction of the setpoint of the ratio controller of the flow rate based on the calculation of the temperature regime.