Modelling, Simulation and Optimization of Small-Scale CCHP Energy Systems

Abstract

The article defines and discusses techno-economic models of CCHP system based on a power system with an internal combustion engine or a gas turbine with electric power of 0,2-1 MW including an absorption or vapour-compression refrigeration unit. The thermodynamic, ecological and economical features of the CCHP system under different load situations are analysed in relation to the basic model of energy generation with boiler and vapour-compression refrigeration unit. Based on the data of the equipment manufacturer, functional dependency curves of individual components are created in dependency to the load, which enables the construction of a system model composed of a power system (internal combustion engine or a gas turbine), single-stage or two-stage absorption refrigeration unit and boiler. A program solution has been developed applying the object-oriented programming language Modelica that enables the insight into the behaviour and techno-economic validity of usage of the analysed systems in transformable operating conditions. The article examines various energetic models, defining for the influential parameters (electric energy and fuel prices, investment costs and the level of heat recovery) the value of total energy efficiency, the return period on investment costs and the environmental impact concerns.

Energy and Exergy Analysis of Waste Heat Recovery Closed-Cycle Gas Turbine System while Operating with Different Medium

“…After that, it will be investigated different system configurations with an aim to find an optimal one for each operating medium. All of newly obtained system configurations will be optimized by using various conventional [83,84] and artificial intelligence methods and techniques, which show its potential not only in marine applications [85,86], but also in energy systems [87], medical applications [88,89], robotics [90], in predicting trends of global (or local) diseases [91][92][93], etc.…”

Hydraulic System of Fuel Oil Supply to the Electronically Controlled Main Engine

“…The above process may be optimized by multilayer perceptron, with achieving lowest specific fuel consumption and minimization of the cylinder process highest temperature for the reducing NOx emission [12,13]. The optimization processes may vary by applied techniques which may include genetic algorithm approach [14][15][16], neural network application [17][18][19][20], program solution with programming languages, such are Modelica [21,22]. However the comprehensive optimization of the fuel oil consumption and the reduction of the NOx emission is not achievable without electronically controlled fuel pressure and injection timing at the wide range operating what is briefly described in the below text.…”

Development of a Numerical Tool for Dynamic Simulations of Two-Phase Cooling Systems

“…A comparison with these data allows validations of the developed tool against a real system. Furthermore, the simulations are also compared against a model developed on the Modelica/Dymola platform (typically used for physical modelling of energy systems [10]). The Dymola model adopts the homogeneous assumption for twophase flow.…”