scholarly journals Advanced exergetic analysis of a heat pump providing space heating in built environment

Energetika ◽  
2017 ◽  
Vol 63 (3) ◽  
Author(s):  
Volodymyr A. Voloshchuk
Keyword(s):  
Built Environment ◽  
Energy Conversion ◽  
Heat Pump ◽  
System Component ◽  
Space Heating ◽  
Exergy Destruction ◽  
Operating Modes ◽  
Conversion System ◽  
Energy Conversion System ◽  
Exergetic Analysis

In addition to conventional exergy-based methods, advanced exergetic analyses consider the interactions among components of the energy-conversion system and the real potential for improving each system component. The paper demonstrates the results of application of a detailed advanced exergetic analysis to a wastewater source heat pump providing space heating in the built environment. In order to determine thermodynamic parameters of the refrigeration vapour compression cycle in different operating modes, the simulation model has been used. The analysis includes splitting the exergy destruction within each component of a heat pump into unavoidable, avoidable, endogenous and exogenous parts as well as detailed splitting of the avoidable exogenous exergy destruction. Besides, variabilities of heating demands of a building within both the chosen heating season and also from year to year are taken into account. Distribution of the split exergy destructions during different periods of time is also presented for the analysed cases of the heat pump and built environment. It is shown that in the investigated system only about 50% of the total annual destruction in components of the heat pump can be avoided. About 30…40% of this avoidable thermodynamic inefficiency is caused by interactions among components. Based on the applied advanced exergetic analysis it is possible to receive more precise and useful information for better understanding and improving the design and operation of the analysed energy-conversion system.

Advanced Exergoeconomic Evaluation and Its Application to Compression Refrigeration Machines

2007 ◽  
Author(s):  
George Tsatsaronis ◽  
Tatiana Morosuk
Keyword(s):  
Energy Conversion ◽  
Exergy Analysis ◽  
System Component ◽  
Exergy Destruction ◽  
Conversion System ◽  
Investment Cost ◽  
Energy Conversion System ◽  
The Cost ◽  
Refrigeration Machine

Splitting the exergy destruction within each component of an energy conversion system into endogenous/exogenous and unavoidable/avoidable parts enhances an exergy analysis and improves the quality of the conclusions obtained from the analysis. The potential for improving each system component is identified and priorities, according to which the design of components should be modified, are established. We call this detailed exergy analysis advanced exergy analysis. For improving the cost effectiveness of an energy conversion system, splitting the investment cost into endogenous/exogenous and unavoidable/avoidable parts is also helpful. The designer should focus on the avoidable thermodynamic inefficiencies (exergy destruction), their costs and the avoidable investment costs. The paper discusses the calculation of these costs in general and the resulting advanced exergoeconomic evaluation that is based on the avoidable endogenous and the avoidable exogenous values for exergy destruction, cost of exergy destruction and investment cost. An application of this methodology to a compression refrigeration machine is presented.

scholarly journals Simulation and Exergy Analysis of a Refrigeration System Using an Open-Source Web-Based Interactive Tool—Comparison of the Conventional Approach and a Novel One for Avoidable Exergy Destruction Estimation

2021 ◽  
Vol 11 (23) ◽  
pp. 11535
Author(s):  
Volodymyr Voloshchuk ◽  
Paride Gullo ◽  
Eugene Nikiforovich ◽  
Nadia Buyak
Keyword(s):  
Energy Conversion ◽  
Open Source ◽  
Exergy Analysis ◽  
Exergy Destruction ◽  
Refrigeration System ◽  
Web Based ◽  
New Approach ◽  
Interactive Tool ◽  
Conversion System ◽  
Energy Conversion System

Avoidable endogenous/exogenous parts of the exergy destruction in the components of an energy conversion system can be computed by applying advanced exergy analysis. Their calculation is crucial for the correct assessment of the real thermodynamic enhancement achievable by the investigated energy conversion system. This work proposes a new approach to estimate the avoidable exergy destruction rates of system components, being more rigorous compared to the conventional method due to the elimination of the need for the implementation of theoretical assumptions associated with the idealization of processes. An open-source web-based interactive tool was implemented to contrast the results of the conventional advanced exergy analysis to those involving the new approach for avoidable exergy destruction estimation. The comparison was based on the same case study, i.e., a refrigeration system selected from the literature. It was observed that the developed tool can be properly employed for comparing the two approaches within exergy analyses, and the results obtained presented some differences for the compressor and the condenser. Compared to the new approach, the existing methodology of advanced exergy analysis suggests lower values of the avoidable part of exergy destruction, which can be reduced by improving the efficiency of the compressor and the condenser. Moreover, the avoidable parts of exergy destruction, which could be removed within these components by improving the efficiencies of the remaining components, were higher in the case of the application of the existing advanced exergetic analysis as compared with the findings obtained by the proposed approach. These differences were due to the impossibility of the existing advanced exergy analysis to implement complete thermodynamic “idealization” for the condenser and evaporator.

Formation of Environmental Impacts in Energy Conversion Processes Revealed by a Novel Exergoenvironmental Analysis

2007 ◽  
Author(s):  
Lutz Meyer ◽  
Jens Buchgeister ◽  
George Tsatsaronis ◽  
Liselotte Schebek
Keyword(s):  
Environmental Impact ◽  
Energy Conversion ◽  
Environmental Impacts ◽  
Ecological Impact ◽  
Economic Problem ◽  
Special Focus ◽  
Exergy Destruction ◽  
Conversion System ◽  
Energy Conversion System ◽  
The Impact

An exergoenvironmental analysis has been developed that reveals to what extent each component of an energy conversion system is responsible for the overall environmental impact, and identifies the sources of the impact. The approach of the exergoeconomic analysis is modified to deal, instead with an economic problem, with an evaluation of the ecological impact. The basic idea is that exergy represents a proper basis for assigning both costs and environmental impact in energy conversion processes. As a case study, an energy conversion system consisting of a high-temperature solid oxide fuel cell integrated with an allothermal biomass gasification process has been analyzed. The exergoenvironmental analysis allows to identify the environmentally most relevant system components and provides information about possibilities for design improvements. A special focus is laid on the role of exergy destruction. It is shown that the location of the exergy destruction in the process has influence on the resulting environmental impacts. A certain amount of exergy destruction leads to a different extent to environmental impacts depending on the position of the component where the exergy destruction occurs. The exergoenvironmental analysis reveals the thermodynamic inefficiencies that have the greatest environmental impacts.

scholarly journals Exergy-based Investigation of Various Heat Pumps for Enhancement of Their Thermodynamic Efficiency

2019 ◽  
pp. 168
Author(s):  
Volodymyr Voloshchuk ◽  
Paride Gullo
Keyword(s):  
Built Environment ◽  
Heat Exchangers ◽  
Heat Pumps ◽  
Space Heating ◽  
Thermodynamic Efficiency ◽  
Exergy Destruction ◽  
Exergetic Analysis

The work demonstrates the results of application of the detailed advanced exergetic analysis to air-source, watersource and wastewater-source heat pumps providing space heating in the built environment. Cumulative values based on seasonal exergy destruction are used for deriving conclusions. It is shown that in the specified conditions of the investigated systems priorities for improving should be given to heat exchangers.

scholarly journals Real-Time Emulation of a Grid-Connected Wind Energy Conversion System Based Double Fed Induction Generator Configuration under Random Operating Modes

2021 ◽  
Vol 23 (3) ◽  
pp. 207-219
Author(s):  
Dekali Zouheyr ◽  
Baghli Lotfi ◽  
Boumediene Abdelmadjid
Keyword(s):  
Power Control ◽  
Energy Conversion ◽  
Wind Turbine ◽  
Dc Motor ◽  
Induction Generator ◽  
Wind Energy Conversion System ◽  
Wind Energy Conversion ◽  
Operating Modes ◽  
Conversion System ◽  
Energy Conversion System

This paper presents the design, modeling, simulation and the experimental implementation of a 1.5 kW relatively low-cost wind energy conversion system (WECS) based on the double fed induction generator (DFIG) configuration. In the preliminary experiments, we test the DFIG power control under fixe speed by applying the vector control principle, then we insert the physical emulator presented in the controlled DC motor in order to simulate the static-dynamic behaviors of a real wind turbine with the use of the Tip Speed Ratio TSR based MPPT algorithm to extract the maximum available power on the emulator. The proposed structure is simulated using MATLAB Simulink environment, the obtained results are validated experimentally on our laboratory setup. We also develop an application with MATLAB AppDesigner that calculates the operating point of our system at steady state and visualize the power transfer, current, voltage and electromagnetic torque values of the DFIG and the DC motor before starting the stimulation or the experimental manipulation. The MPPT, the DC motor control and the DFIG power control algorithms are implanted in C, embedded on a dSPACE DS1104 control board. The obtained results confirm the reliability of the proposed WECS to manage all the probable operating modes, also the effectiveness of the physical simulator in the role of wind turbine emulation.

scholarly journals Exergy analysis of a reversible chiller

2021 ◽  
pp. 105-106
Author(s):  
Volodymyr Voloshchuk ◽  
Olena Nekrashevych ◽  
Volodymyr Voloshchuk ◽  
Pavlo Gikalo
Keyword(s):  
Heat Exchangers ◽  
Exergy Analysis ◽  
System Component ◽  
Space Heating ◽  
Exergy Destruction ◽  
Exergetic Analysis ◽  
Operational Modes

The work presents the results of exergetic analysis of a reversible chiller providing both cooling and space heating in varying operational modes. The year values of avoidable parts of exergy destruction occurring in each system component are used for the analysis. The outcomes obtained showed that the both inside and outside heat exchangers have the highest priority for improvement revealing more than 718 kW-hr avoidable year exergy destruction within the system.

Strengths and Limitations of Advanced Exergetic Analyses

2013 ◽  
Author(s):  
T. Morosuk ◽  
G. Tsatsaronis
Keyword(s):  
Energy Conversion ◽  
System Component ◽  
Real Potential ◽  
Hybrid Processes ◽  
Conventional Analysis ◽  
Energy Conversion Systems ◽  
Energy Conversion System ◽  
Exergetic Analysis ◽  
Definition Of ◽  
The Ideal

The exergetic analysis is a powerful tool for developing, evaluating and improving an energy conversion system. The strengths and limitations of the so-called conventional exergetic analysis have already been discussed. An advanced exergetic analysis can significantly reduce some of the limitations of a conventional analysis by evaluating (a) the detailed interactions between components of the overall system, and (b) the real potential for improving a system component. The main objective of advanced exergy-based analyses is to provide engineers with additional useful information for better understanding and improving the design and operation of energy-conversion systems. This information cannot be supplied by any other approach. The weaknesses of an advanced exergetic analysis are associated with (a) the subjectivity that is associated with the calculation of avoidable exergy destruction and with the definition of both the ideal and the so-called hybrid processes, and (b) the large number of calculations that need to be conducted to obtain the avoidable endogenous and the avoidable exogenous values.

Sign in / Sign up

Export Citation Format

Share Document