Techno-economic aspects of increasing primary energy efficiency in industrial branches using thermal energy storage

2021 ◽  
Vol 36 ◽  
pp. 102344
Author(s):  
Stefan Puschnigg ◽  
Johannes Lindorfer ◽  
Simon Moser ◽  
Thomas Kienberger
Keyword(s):  
Energy Efficiency ◽  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Primary Energy ◽  
Economic Aspects

Design, exergy and exergoeconomic analysis and optimization of a CCHP + TES for the use in a complex building

2020 ◽  
Vol 41 (6) ◽  
pp. 727-744
Author(s):  
Khodadoost Rostami Zadeh ◽  
Seyed Ali Agha Mirjalily ◽  
Seyed Amir Abbas Oloomi ◽  
Gholamreza Salehi
Keyword(s):  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Annual Cost ◽  
Combustion Engine ◽  
Operating Cost ◽  
Operating Time ◽  
Primary Energy ◽  
The Public ◽  
Return On Capital

The present paper aims at the optimization and exergy and thermoeconomic analyses of a combined cooling, heat, and power generation system equipped with a thermal energy storage for the use in a residential complex with a gas-fueled internal combustion engine as the prime mover. The system is optimized using the direct search method by minimizing annual cost in two cases of using/not using a thermal energy storage. In case of the use of a thermal energy storage, an engine with a capacity of 2 MW and an operating time of 4000 h are found to be optimal, but when a thermal energy storage is included, an engine with a capacity of 2 MW and an operating time of 5268 hours and a thermal energy storage with a capacity of 18.93 m3 are found to be the optimal options. Both systems are evaluated assuming selling/not selling surplus power to the public power grid. The best case for the performance of the system is to use a thermal energy storage and to sell surplus electricity to the grid. In this case versus the case of excluding the thermal energy storage, primary energy consumption, CO2 emission, operating cost of the system, and power purchase from the public grid are decreased by 20.8, 19.5, 14.3 and 17%, respectively while return on capital is increased by 3.1% resulting in 10.7% higher annual cost of the system.

Energy and Exergy Analysis of Thermal Energy Storage Prototype by Using Concrete Material in Thailand

2016 ◽  
Vol 839 ◽  
pp. 14-22
Author(s):  
Rungrudee Boonsu ◽  
Sukruedee Sukchai
Keyword(s):  
Heat Transfer ◽  
Energy Efficiency ◽  
Energy Storage ◽  
Flow Rate ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Heat Transfer Fluid ◽  
Saturated Steam ◽  
Fluid Temperature ◽  
Flow Rates

The research was performed on thermal energy storage prototype in Thailand. Concrete was used as the solid media sensible heat material in order to fulfill local material utilization which is easy to handle and low cost. Saturated steam was used for heat transfer fluid. The thermal energy storage prototype was composed of pipes embedded in a concrete storage block. The embedded pipes were used for transporting and distributing the heat transfer medium while sustaining the pressure. The heat exchanger was composed of 16 pipes with an inner diameter of 12 mm and wall thickness of 7 mm. They were distributed in a square arrangement of 4 by 4 pipes with a separation of 80 mm. The storage prototype had the dimensions of 0.5 x 0.5 x 4 m. The charging temperature was maintained at 180°C with the flow rates of 0.009, 0.0012 and 0.014 kg/s whereas the inlet temperature of the discharge was maintained at 110°C. The performance evaluation of a thermal energy storage prototype was investigated in the part of charging/discharging. The experiment found that the increase or decrease in storage temperature depends on the heat transfer fluid temperature, flow rates, and initial temperature. The energy efficiency of the thermal energy storage prototype at the flow rate of 0.012 kg/s was the best because it dramatically increased and gave 41% of energy efficiency in the first 45 minutes after which it continued to rise yet only gradually. Over 180 minutes of operation time, the energy efficiency at this flow rate was 53% and the exergy efficiency was 38%.

Performance Assessment of an Aquifer Thermal Energy Storage System for Heating and Cooling Applications

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Abdullah A. AlZahrani ◽  
Ibrahim Dincer
Keyword(s):  
Energy Efficiency ◽  
Energy Storage ◽  
Performance Assessment ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Cooling System ◽  
Temperature Sensitive ◽  
Heating And Cooling ◽  
Aquifer Thermal Energy Storage ◽  
Energy And Exergy

This study presents energy and exergy analyses of aquifer thermal energy storage (ATES) integrated with a building heating and cooling system. In this regard, a typical bidirectional ATES integrated with a heat pump (HP) is considered in the provision of required heating and cooling demands. The different ATES components and the operating principle are described. Furthermore, energy and exergy models are formulated for three subprocesses: charging, storing, and discharging, to track changes in energy and exergy quantities with discharging time. The energetic and exergetic efficiencies are then evaluated for both operating cases. The limitation of the use of energy efficiency for ATES performance assessment is elaborated. In contrast, the importance of exergy analysis as a practical and temperature sensitive tool is considered as a quantitative and a qualitative measure of the ATES performance. Additionally, a comparison between energetic and exergetic efficiencies is presented where energy efficiency involves some ambiguities, especially when energy recovered from ATES is at a low temperature rather than at an ambient temperature.

scholarly journals Thermodynamic Analysis of a High-Temperature Latent Heat Thermal Energy Storage System

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6634
Author(s):  
David W. MacPhee ◽  
Mustafa Erguvan
Keyword(s):  
Heat Transfer ◽  
Energy Efficiency ◽  
Energy Storage ◽  
Entropy Generation ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Storage System ◽  
Volume Ratio ◽  
Melting Time ◽  
Inlet Temperature

Thermal energy storage (TES) technologies are becoming vitally important due to intermittency of renewable energy sources in solar applications. Since high energy density is an important parameter in TES systems, latent heat thermal energy storage (LHTES) system is a common way to store thermal energy. Though there are a great number of experimental studies in the field of LHTES systems, utilizing computational codes can yield relatively quick analyses with relatively small expense. In this study, a numerical investigation of a LHTES system has been studied using ANSYS FLUENT. Results are validated with experiments, using hydroquinone as a phase-change material (PCM), which is external to Therminol VP-1 as a heat transfer fluid (HTF) contained in pipes. Energy efficiency and entropy generation are investigated for different tube/pipe geometries with a constant PCM volume. HTF inlet temperature and flow rate impacts on the thermodynamic efficiencies are examined including viscous dissipation effects. Highest efficiency and lowest entropy generation cases exist when when flow rates are lowest due to low viscous heating effects. A positive relation is found between energy efficiency and volume ratio while it differs for entropy generation for higher and lower velocities. Both efficiency and entropy generation decreased with decreasing HTF inlet temperature. The novelty of this study is the analysis of the effect of volume ratio on system performance and PCM melting time which ultimately proved to be the most dominant factor among those considered herein. However, as PCM solidification and melting time is of primary importance to system designers, simply minimizing entropy generation by decreasing volume ratio in this case does not lead to a practically optimal system, merely to decrease heat transfer entropy generation. Therefore, caution should be taken when applying entropy analyses to any LHTES storage system as entropy minimization methods may not be appropriate for practicality purposes.

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