J. Kalina

Thermoeconomic Evaluation of Biomass Conversion Systems

The chapter presents the application of thermoeconomics to the analysis of a sample biomass energy conversion system. Thermoeconomics is aimed at the analysis, optimization and diagnosis of energy conversion systems; it is based on the concept of exergy which is constantly gaining more popularity among engineers and researchers, and the concept of cost. The case study chosen for demonstrating the usefulness of the methodology concerns an integrated biomass gasification and utilization system with an atmospheric fluidized bed gasification unit and a gas turbine unit fed with the produced gas. Definition of fuel and product flows allows one to identify key components responsible for conversion of the largest amounts of exergy. Further concepts of thermoeconomics, such as exergy cost and its formation process allow one to determine the quality of each component of the plant. Attention is paid to the explanation of methodology rather than to particular technological issues, which are explained in the cited references, and are also subject of other chapters of this book.

Small‐scale co‐generation for building applications ‐ energy demand analysis at demonstration site and optimal sizing of the CHP plant

Abstract Aspects of using the small‐scale combined heat and power modules in buildings is presented in this paper. At first the problems of energy demand analysis, which is the key point of a co‐generation plant sizing procedure, are discused. Then the demonstration project of a small‐scale co‐generation plant is presented. The plant is fuelled with natural gas, and it supplies energy to a group of three different buildings. Basing on this case, the problems of optimal sizing of a small‐scale CHP plant for a building energy supply system are presented and discussed. Calculation procedures are shown together with the results of sample analysis. The factors influencing the final configuration of the system are indicated.

Integrated Biomass Gasification Small-Scale Combined Cycle Distributed Generation Plant With Microturbine and ORC

The objective of this work is to evaluate thermodynamic and economic performance of a small-scale combined cycle plant with microturbine and ORC. The primary source of fuel for the plant is wood. The biomass is converted into a gaseous fuel by means of gasification in a downdraft fixed bed reactor. Size of the plant is limited to 350 kg/h of wet biomass input into the gasifier. Two alternative configurations of the bottoming ORC cycle are taken into account: single stage cycle and cascade cycle. In the first case R123 and n-pentane are analyzed as potential working fluids. In the cascade cycle toluene and n-pentane are selected for top and bottom cycle respectively. Electricity generation efficiency of the proposed small-scale plant is at the level of 23%, that is comparable with direct combustion based systems of much higher electric output. An initial economic evaluation of a sample project gives an outlook on economic effectiveness, that nowadays is strongly dependent on stimulation measures for “green” electricity generation.Copyright

Analysis of Wind Farm—Compressed Air Energy Storage Hybrid Power System

This paper presents a hybrid system which consists of wind turbines and compressed air energy storage (CAES) facility. The inclusion of CAES into an existing wind farm helps to control power output of the entire plant. Due to wind farm location the considered CAES system was assumed to be a small scale with above ground air vessels. Mathematical, dynamic simulation of CAES model was performed. Conclusions on annual co-operation of CAES systems with wind turbines are presented.