The task of choosing the criterion of energy efficiency of operation of city gas networks of high and medium pressure, under the condition of transition to the system of individual energy supply is set and solved. It is shown
that in conditions of substantial increase of prices for natural gas and deepening of its deficit, the city gas network is often not able to provide consumers with energy in a given volume, so the approach to forecasting its operating modes should fundamentally change. First of all it concerns the field of permissible modes, which in such conditions considerably expands. Given the reloading of the gas distribution network as a result of changing the nature of gas consumption, a large role is given to the criteria for energy efficiency of gas transportation and to ensure maximum operational reliability while being within the scope of optimal maintenance.
In order to assess the energy efficiency of gas transportation by gas pipelines of a distribution network, it is suggested to use the notion of the net efficiency coefficient, which is determined by the ratio of useful work performed when providing a given volume of gas transportation by pipelines to total energy consumption. It is shown that the efficiency of the distribution network or its individual elements differs fundamentally from the coefficient of its hydraulic efficiency, which is a characteristic of the technical state of the system. On the basis of analytical studies, the correlation between them is established.
Calculated dependencies are proposed for determining the coefficient of hydraulic efficiency of a branched gas pipeline as an element of an urban gas distribution network. The influence of various factors on the value of the coefficient of hydraulic efficiency of the urban gas distribution network has been analyzed. The examples of calculating the efficiency of the network are given, conclusions on improving the efficiency of operation are made.