The design of integrated energy systems (IESs) is a challenging task by reason of the highly complex configurations of these systems, the wide range of equipment used, and a diverse set of mathematical models and dedicated software employed to model it. The use of digital twins allows modeling in virtual space for various IES configurations. As a result, an optimal option of IES is obtained, which is implemented in the construction or expansion of a real-world IES. The paper proposes the principles of building digital twins for solving the IES design problems. The paper presents a new methodological approach developed by the authors to design an IES with the help of its digital twin. This approach includes the following components: the architecture of the software platform to create digital twins, a set of technologies and tools to implement the platform, methods to automatically construct a digital twin based on the Model-Driven Engineering concept, an algorithm to design an IES based on its digital twin, and principles to organize a computational process using a multi-agent approach. The results of the computational experiment using the software implementation of the IES digital twin components are presented for a test energy supply scheme.

The authors describe the new generation of the software system intended for the schematic-parametric optimization of multi-circuit heat supply systems (MC HSS) that make it possible to perform calculations of such systems having an intrinsic structure with any set of nodes, sections, and circuits. The expanded architecture of the software system used in organizing a flexible adaptive model of the computational process management is presented.

The problem of finding optimal parameters of a heat-supply system (HSS) is in ensuring the required throughput capacity of a heat network by determining pipeline diameters and characteristics and location of pumping stations. Effective methods for solving this problem, i.e., the method of stepwise optimization based on the concept of dynamic programming and the method of multicircuit optimization, were proposed in the context of the hydraulic circuit theory developed at Melentiev Energy Systems Institute (Siberian Branch, Russian Academy of Sciences). These methods enable us to determine optimal parameters of various types of piping systems due to flexible adaptability of the calculation procedure to intricate nonlinear mathematical models describing features of used equipment items and methods of their construction and operation. The new and most significant results achieved in developing methodological support and software for finding optimal parameters of complex heat supply systems are presented: a new procedure for solving the problem based on multilevel decomposition of a heat network model that makes it possible to proceed from the initial problem to a set of interrelated, less cumbersome subproblems with reduced dimensionality; a new algorithm implementing the method of multicircuit optimization and focused on the calculation of a hierarchical model of a heat supply system; the SOSNA software system for determining optimum parameters of intricate heat-supply systems and implementing the developed methodological foundation. The proposed procedure and algorithm enable us to solve engineering problems of finding the optimal parameters of multicircuit heat supply systems having large (real) dimensionality, and are applied in solving urgent problems related to the optimal development and reconstruction of these systems. The developed methodological foundation and software can be used for designing heat supply systems in the Central and the Admiralty regions in St. Petersburg, the city of Bratsk, and the Magistral’nyi settlement.

This chapter presents new methods and software system SOSNA intended for the parameter optimization of heat supply systems. They make it possible to calculate large-scale systems which have a complex structure with any set of nodes, sections, and circuits. A new methodological approach to solving the problem of the parameter optimization of the heat supply systems is developed. The approach is based on the multi-level decomposition of the network model, which allows us to proceed from the initial problem to less complex sub-problems of a smaller dimension. New algorithms are developed to numerically solve the parameter optimization problems of heat supply systems: an effective algorithm based on the multi-loop optimization method, which allows us to consider hierarchical creation of the network model in the course of problem solving; a parallel high-speed algorithm based on the dynamic programming method. The new methods and algorithms were used in the software system SOSNA.

The paper presents a new methodological approach to the automated construction of software for solving the design problems of heating systems. The methodological approach is based on the Model-Driven Engineering paradigm. The essence of this paradigm is that the software is generated on the basis of formal description represented by models. The knowledge about heating systems, applied problems, and the applied software is formalized in the form of ontologies. The automated construction of the software system is performed on the basis of a computer model of a heating system, the ontologies and modern metaprogramming technologies. The proposed approach allows us to successfully solve the problem of separation of methods for solving applied problems and models of heating system elements. To this end, the methods are implemented in the form of software components that are not related to properties and models of specific equipment. And the models of heating system elements are automatically compiled into software components. In the process of software system construction, software components that implement models and methods are integrated dynamically. As a result, the software system oriented to solving a specific applied problem is created in an automated mode. The developed approach has been used for the implementation of the SOSNA software. The software is applied to design urban heating systems.

The problem of optimizing the transmission capacity of a pipeline network is important for ensuring its operability. The problem arises at different stages of the network life cycle (design, optimization, development). The problem is to determine the diameters of the pipelines, the locations of the pumps and the heads on them, the locations of the regulators (flow and pressure) and their parameters. The article proposes a new algorithm based on dynamic programming, which implements an original approach to organizing a computational procedure. The general principles of the algorithm and the content of its steps do not depend on the purpose of the network and the composition of its equipment. The algorithm is versatile and allows one to optimize networks for various purposes. The proposed algorithm is implemented in the IRNET software. On its basis, calculations were made for the development of real district heating systems.