Discrete-continuous optimization of heat network operating conditions in parallel operation of similar pumps at pumping stations

Abstract

The paper addresses an optimization problem of hydraulic conditions of heat supply systems. The research shows that when the main methods of operation control, including the control of the number of connected pumps at pumping stations, are used this problem is reduced to a mixed discrete-continuous programming problem which involves a nonlinear objective function, nonlinear equality constraints and simple inequalities. The paper presents the basic principles of the methods for calculation of feasible and optimal conditions on the basis of continuous variables as a constituent of the suggested technique for solving the general problem. Consideration is given to four possible strategies to fraction and cut the variants while searching for solutions on the basis of discrete variables. The results of computational experiments illustrating the comparative efficiency of different strategies are presented.Keywords Discrete-continuous optimization · Strategies for problem solving on the basis of continuous and integer-valued variables · Hydraulic conditions · Heat supply systems

Optimization of hydraulic modes of single-source tree-like heat networks

“…The requirements of acceptability and realizability of the mode are usually written as [20] jjj PPP ,…”

“…The following approach was used as a reference method. First, the values of all Boolean variables were set equal to one and fixed, then the HSS HM with the economic objective function was optimized using the method presented in [20]. After that, to fix the values of FC, the values of i  and i  , iI  were fixed and optimization was performed for the technological objective functions using the method described in [21].…”

“…Then Let J be the set of all nodes, Jm  . As the hydraulic characteristics of the i-th branch can be taken [20]: 22 ( , , , ) /…”

“…From these features and the form of setting the boundary conditions follows a fixed flow distribution. In this case, the model of controlled flow distribution used in [20], will take the form:…”

Aggregation of distribution heating networks in the problems of hierarchical optimization of large heat supply systems

“…For DHN, due to the branched configuration, there is a fixed, easily computable flow distribution. Accordingly, the model of controlled flow distribution [14] will take the form:…”