Thermoeconomical optimization of a regenerative air turbine cogeneration system

Andrii Kostikov,Victoriia Tarasova,Mikhail Kuznetsov,Marat Satayev,Dionis Kharlampidi

doi:10.18186/thermal.1025958

Abstract

The concept of optimization of operating and design parameters of the regenerative air turbine cogeneration (RATC) system is proposed. To determine the energy efficiency indicators of this system, its thermodynamic analysis was performed. At the same time, it is shown that it is not correct to search for the optimal parameters of such a system only by energy indicators, and modern thermoeconomic methods should be more actively involved in pre-design practice, which allow a comprehensive evaluation of the efficiency and economy of the energy-technological system as a whole and its individual elements. Therefore, on the basis of the data obtained during the thermodynamic analysis, exergy destruction and losses in the main system elements were calculated. Then, using the structural-variant method in combination with the graphical apparatus of C-curves, the pre-project thermoeconomic optimization of the RATC system was performed. This made it possible to choose the optimal operating and design parameters of the system and determine the minimum cost for its creation and operation throughout the entire life cycle, taking into account the thermodynamic perfection of the main system elements. Each variable operating mode parameter of the system serves as a kind of navigator when searching for the option of system parameters that is optimal in terms of energy and economic indicators, which is accompanied by graphic visualization. Therefore, the proposed approach makes the optimization of the system being designed convenient and clear. It can be used in the optimal design of various types of thermal transformers and other energy-technological systems.

Highlights

Much of the thermal and electrical energy both in Ukraine and in the world is generated by large thermal power plants (TPP) and combined heat and power plants (CHPP) whose power units have efficiency level of 35-37%, and the power units using low-calorie fuels have the efficiency that does not exceed even 15%
This is due to the fact that with decreasing T3, the mass flow rate of air turbine upstream air increases (Figure 3)
This is due to the fact that an increase in πc leads to a decrease in mass flow rate of the air turbine upstream air (Figure 3), it leads to an increase in compressor outlet air pressure (P2) and air turbine upstream air pressure (P3)

Summary

Introduction

Much of the thermal and electrical energy both in Ukraine and in the world is generated by large thermal power plants (TPP) and combined heat and power plants (CHPP) whose power units have efficiency level of 35-37%, and the power units using low-calorie fuels have the efficiency that does not exceed even 15%. One of the progressive solutions to existing energy problems is the construction of small TPPs with cost effective and environmentally friendly cogeneration systems (miniCHPPs). Against this background, in 2005, Ukraine adopted the Law on Combined Heat and Power (Cogeneration) and the Use of Waste Energy Potential. In 2005, Ukraine adopted the Law on Combined Heat and Power (Cogeneration) and the Use of Waste Energy Potential Such cogeneration using a single primary energy source can increase fuel efficiency from 30–40% to 85–90% [1,2]. The development of the concept of creating smallsized high-efficiency environmentally friendly low-power cogeneration systems where renewable fuel sources can be used as fuel is an urgent scientific problem

Objectives

Methods

Discussion

Conclusion