THE RELIABILITY AND EFFICIENCY OF MEDIUM-TEMPERATURE DISTRICT HEATING
The goal of this paper is to provide a scenario and a methodology that focuses on solutions for optimal network design to enable failure-free operation. If both reliability and energy-efficiency are the focus targets, low operating temperatures are desirable in a district heating system, from standpoint of the distribution network and the heat source. The equivalent diameter of the network using the medium pipe diameter, its length, and the total network length was defined. For simplification, we propose to determine the calculated and the standard heat losses by modeling the object of research using mathematical flow distribution models implemented in the corresponding geoinformation systems and software simulation package complexes (for example, Zulu). An urban area of the town of Barabinsk was designated as a test site; the area represented the attributes of many communities across Russia. We have proposed a concept for introducing medium-temperature district heating systems and a method of using existing tools to justify its implementation. The procedure we have developed allows to quickly compare the generalized technical and economic indicators of various reconstruction options for such facilities without resorting to purely economic characteristics and monetary indicators. We aimed at organizing the successive steps of a typical feasibility study, pointing out the critical issues and discussing the possible solutions. We applied the methodology to a specific case study, but it can be applied elsewhere, after making sure that the economic and technical input data match the actual conditions of the site considered. Medium-temperature district heating had a better energy performance than high-temperature district heating, decreasing the heat loss by approximately 5%. The sizes of the pipes size equivalent and the only difference was the necessity of using steel pipes. The low-temperature networks required more energy and additional capital investment. At the same time, the introduction of low-temperature heating should be considered as a long-term measure, since from a socio-economic standpoint this will allow to connect individual renewable energy sources and consumers using heat power with a high efficiency to the existing heat networks.