Modelling and Validation of a Hybrid Trigeneration/Photovoltaic System Installed in a Shopping Mall Complex

2017 ◽  
Author(s):  
Aldo López Vega ◽  
Gregory J. Kowalski ◽  
Carlos Rubio-Maya ◽  
J. Jesús Pacheco Ibarra
Keyword(s):  
Experimental Data ◽  
Thermal Energy ◽  
Operating Conditions ◽  
Hot Water ◽  
Fuel Oil ◽  
Photovoltaic System ◽  
Shopping Mall ◽  
Second Law ◽  
National Council ◽  
Effective Manner

Shopping malls require large amount of electrical and thermal energy to provide quality services and maintain customer’s comfort. Conventionally, electrical energy for direct use and operation of HVAC systems is supplied directly from the electrical grid and is produced in remote power plants that burns fossil fuels. Thermal energy for hot water or heating supply is usually produced by boilers that use LP gas or fuel oil. Given these conditions, cogeneration and trigeneration systems supported by renewable sources of energy are ideal schemes to meet energy needing in a more efficient and cost-effective manner. For this reason, a hybrid trigeneration/photovoltaic system has been installed to cover approximately 50% of the electrical and thermal demands of a shopping mall complex, located in Morelia (MichoacÁn, Mexico). The trigeneration plant consists of a microturbine with an electric power output of 65 kW, three absorption chillers with an output of 5 RT each and a photovoltaic system of 30 kW of electrical power, composed of 108 photovoltaic modules of 280 W each. The Incentive Program for Technology Innovation of the National Council of Science and Technology has funded and sponsored the project and it is to demonstrate on-site feasibility under the Mexican energy context. The installation will generate information on the global and specific operation of the components. In this paper, the development and validation of thermodynamic models to analyze and simulate the individual and integral operation of the hybrid trigeneration/photovoltaic system components is presented. These models based on the First and Second law will allow an integral simulation of the plant to determine the most appropriate operating conditions. The First and Second law efficiencies as well as the exergy destruction in each component is reported. The models have been developed from data provided by manufacturers and the application of mass, energy and exergy balances. The validation of models has been carried out using experimental data acquired directly from the components of the plant and other measurement instruments that have been used for this purpose. The results of the models have been compared with experimental data and have showed satisfactory agreement, with an average difference of 2.92%.

Analysis of the Design and Operation of a Hybrid Trigeneration-Photovoltaic System Installed in a Shopping Mall

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Aldo López Vega ◽  
Carlos Rubio-Maya ◽  
Gregory J. Kowalski ◽  
J. Jesús Pacheco Ibarra
Keyword(s):  
Net Present Value ◽  
Maximum Energy ◽  
Operating Conditions ◽  
Photovoltaic System ◽  
Shopping Mall ◽  
Second Law ◽  
Exergy Destruction ◽  
Present Value ◽  
Actual Operating ◽  
Overall Performance

Abstract In this paper, the analysis of the design and operation of a hybrid trigeneration/photovoltaic system installed in a shopping mall is presented. Thermodynamic models based on the first and second laws are developed to analyze all the system's components individually and integrated all together in a trigeneration scheme. Thermodynamics models were validated through experimental data obtained from the equipment running on site. Once the models were validated, it was possible to analyze the actual operating conditions to determine the suitability of the design configuration and to predict the overall performance of the system. In the analysis of the system's design, the first and second law efficiencies, the exergy of each stream, as well as the exergy destruction in each component are reported. In the analysis of the system's operation, several scenarios under different operating conditions were studied and the most suitable scenario was determined by applying an economic analysis based on the net present value. The results show the configuration on which the maximum energy efficiency of the system is obtained as well as the best operation strategy where the greatest economic savings are achieved.

A Small Gas Turbine Plant for Cogeneration of Electricity, Thermal and Cooling Thermal Energy With an Absorption Unit

1997 ◽  
Author(s):  
Maurizio De Lucia ◽  
Carlo Lanfranchi ◽  
Antonio Matucci
Keyword(s):  
Gas Turbine ◽  
Thermal Energy ◽  
Operating Conditions ◽  
Hot Water ◽  
Plant Performance ◽  
Cooling Power ◽  
Operating Parameters ◽  
The European Union ◽  
Cogeneration Plant ◽  
Two Stage

A cogeneration plant with a small gas turbine was installed in a pharmaceutical factory and instrumented for acquiring all the values necessary to appraise both its energetic and cost advantages. The plant was designed and built as a demonstrative project under a program for energy use improvement in industry, partially financed by the European Union. The system comprises as its main components: 1) a gas turbine cogeneration plant for production of power and thermal energy under the form of hot water, superheated water, and steam; 2) a two-stage absorption unit, fueled by the steam produced in the cogeneration plant, for production of cooling thermal energy. The plant was provided with an automatized control system for the acquisition of plant operating parameters. The large amount of data thus provided made it possible to compare the new plant, under actual operating conditions, with the previously existing cooling power station with compression units, and with a traditional power plant. This comparative analysis was based on measurements of the plant operating parameters over nine months, and made it possible to compare actual plant performance with that expected and ISO values. The analysis results reveal that gas turbine performance is greatly affected by part-load as well as ambient temperature conditions. Two-stage absorber performance, moreover, turned out to decrease sharply and more than expected in off-design operating conditions.

scholarly journals Design, Modeling, and Experimental Investigation of Active Water Cooling Concentrating Photovoltaic System

2020 ◽  
Vol 12 (13) ◽  
pp. 5392 ◽  
Author(s):  
Mohamed R. Gomaa ◽  
Mujahed Al-Dhaifallah ◽  
Ali Alahmer ◽  
Hegazy Rezk
Keyword(s):  
Thermal Energy ◽  
Thermal Power ◽  
Qualitative Evaluation ◽  
Operating Conditions ◽  
Photovoltaic System ◽  
Coolant Fluid ◽  
Working Fluid ◽  
Performance Study ◽  
Pv System ◽  
The Cost

This work presents performance study of a concentrating photovoltaic/thermal (CPV/T) collector and its efficiency to produce electric and thermal power under different operating conditions. The study covers a detailed description of flat photovoltaic/thermal (PV/T) and CPV/T systems using water as a cooling working fluid, numerical model analysis, and qualitative evaluation of thermal and electrical output. The aim of this study was to achieve higher efficiency of the photovoltaic (PV) system while reducing the cost of generating power. Concentrating photovoltaic (CPV) cells with low-cost reflectors were used to enhance the efficiency of the PV system and simultaneously reduce the cost of electricity generation. For this purpose, a linear Fresnel flat mirror (LFFM) integrated with a PV system was used for low-concentration PV cells (LCPV). To achieve the maximum benefit, water as a coolant fluid was used to study the ability of actively cooling PV cells, since the electrical power of the CPV system is significantly affected by the temperature of the PV cells. This system was characterized over the traditional PV systems via producing more electrical energy due to concentrating the solar radiation as well as cooling the PV modules and at the same time producing thermal energy that can be used in domestic applications. During the analysis of the results of the proposed system, it was found that the maximum electrical and thermal energy obtained were 170 W and 580 W, respectively, under solar concentration ratio 3 and the flow rate of the cooling water 1 kg/min. A good agreement between the theoretical and experimental results was confirmed.

Utilization of Tea Tree Branches as a Source of Thermal Energy

2020 ◽  
Vol 849 ◽  
pp. 8-13
Author(s):  
Rudi Firyanto ◽  
Heru Susanto ◽  
Retno S.L. Ambarwati ◽  
Suherman ◽  
Widayat
Keyword(s):  
Thermal Energy ◽  
Scale Up ◽  
Operating Conditions ◽  
Fuel Oil ◽  
Optimum Operating ◽  
Large Contribution ◽  
Drying Process ◽  
Processing Industry ◽  
Tea Plantations ◽  
Gasification Technology

Energy has an important role in the survival of the tea processing industry. The costs for energy generation and application have a large contribution to the total cost of the tea processing. The use of fuel oil and electricity, especially in the drying process is the biggest energy user stage. In line with the development of Indonesia's tea processing industry, it is felt necessary to immediately utilize the source of biomass in tea plantations through the application of gasification technology. The development of tea processing in the future should pay more attention to aspects of energy and the environment as the main discussion. This study aims to examine the development of gasification technology in converting biomass as thermal energy to meet gas quality in the tea drying process. The hypothesis is that through the gasification biomass technology of tea plantations, will produce gas as thermal energy that meets the quality of the tea drying process. The target to be achieved is in the form of laboratory technical data for the design, operation of the process, scale-up and evaluation of the performance of the gasifier which includes flame propagation, simulation of combustion and optimum operating conditions with temperature process variables, air flow rate and gas products, tea biomass capacity, and the length of the gasification process.

Low Salinity Hot Water Injection With Addition of Nanoparticles for Enhancing Heavy Oil Recovery

2019 ◽  
Vol 141 (7) ◽  
Author(s):  
Yanan Ding ◽  
Sixu Zheng ◽  
Xiaoyan Meng ◽  
Daoyong Yang
Keyword(s):  
Thermal Energy ◽  
Oil Recovery ◽  
Heavy Oil ◽  
Water Injection ◽  
Operating Conditions ◽  
Hot Water ◽  
Wettability Alteration ◽  
Heavy Oil Recovery ◽  
Oil Saturation ◽  
Low Salinity

In this study, a novel technique of low salinity hot water (LSHW) injection with addition of nanoparticles has been developed to examine the synergistic effects of thermal energy, low salinity water (LSW) flooding, and nanoparticles for enhancing heavy oil recovery, while optimizing the operating parameters for such a hybrid enhanced oil recovery (EOR) method. Experimentally, one-dimensional displacement experiments under different temperatures (17 °C, 45 °C, and 70 °C) and pressures (about 2000–4700 kPa) have been performed, while two types of nanoparticles (i.e., SiO2 and Al2O3) are, respectively, examined as the additive in the LSW. The performance of LSW injection with and without nanoparticles at various temperatures is evaluated, allowing optimization of the timing to initiate LSW injection. The corresponding initial oil saturation, production rate, water cut, ultimate oil recovery, and residual oil saturation profile after each flooding process are continuously monitored and measured under various operating conditions. Compared to conventional water injection, the LSW injection is found to effectively improve heavy oil recovery by 2.4–7.2% as an EOR technique in the presence of nanoparticles. Also, the addition of nanoparticles into the LSHW can promote synergistic effect of thermal energy, wettability alteration, and reduction of interfacial tension (IFT), which improves displacement efficiency and thus enhances oil recovery. It has been experimentally demonstrated that such LSHW injection with the addition of nanoparticles can be optimized to greatly improve oil recovery up to 40.2% in heavy oil reservoirs with low energy consumption. Theoretically, numerical simulation for the different flooding scenarios has been performed to capture the underlying recovery mechanisms by history matching the experimental measurements. It is observed from the tuned relative permeability curves that both LSW and the addition of nanoparticles in LSW are capable of altering the sand surface to more water wet, which confirms wettability alteration as an important EOR mechanism for the application of LSW and nanoparticles in heavy oil recovery in addition to IFT reduction.

scholarly journals Improving electrical energy and producing thermal energy in solar photovoltaic system by integrating phase change materials

2021 ◽  
Vol 297 ◽  
pp. 01021
Author(s):  
Hind Hassoune ◽  
Mouna Ben zohra ◽  
Amine Riad ◽  
Abdelilah Alhamanyi
Keyword(s):  
Phase Change ◽  
Thermal Energy ◽  
Phase Change Materials ◽  
Photovoltaic Cells ◽  
Electrical Energy ◽  
Radiation Energy ◽  
Hot Water ◽  
Photovoltaic System ◽  
Solar Panels ◽  
Solar Photovoltaic System

Solar energy is a natural source that provides clean and renewable energy, which supplies two types of energy: thermal energy and photovoltaic energy. Whereas, the most effective way to exploit this energy is photovoltaic cells. However, for all the incident solar radiation, the solar panels can absorb a limited quantity of energy. While, the rest of radiation energy gets lost as heat, that increases the temperature of the photovoltaic cells, this is the reason why the productivity of electricity is decreased. Therefore, to exceed this issue and benefit from the two sources of sun radiation, a hybrid thermo-electrical system is proposed. The system is a solar panel surrounded by the phase change material that can absorb the temperature to increase the efficiency of solar system and use this energy to produce a hot water.

Greenhouses, hot water bottles, cycles and the future of New Zealand climate

2009 ◽  
pp. 61-67
Author(s):  
W.P. De Lange
Keyword(s):  
New Zealand ◽  
Thermal Energy ◽  
Infrared Radiation ◽  
Little Ice Age ◽  
Hot Water ◽  
Ice Age ◽  
The Sun ◽  
Weather Patterns ◽  
Time Periods ◽  
Almost All

The Greenhouse Effect acts to slow the escape of infrared radiation to space, and hence warms the atmosphere. The oceans derive almost all of their thermal energy from the sun, and none from infrared radiation in the atmosphere. The thermal energy stored by the oceans is transported globally and released after a range of different time periods. The release of thermal energy from the oceans modifies the behaviour of atmospheric circulation, and hence varies climate. Based on ocean behaviour, New Zealand can expect weather patterns similar to those from 1890-1922 and another Little Ice Age may develop this century.

Thermal Energy Storage Through Melting of a Commercial Phase Change Material in an Annulus with Radially Divergent Longitudinal Fins

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Tonny Tabassum Mainul Hasan ◽  
Latifa Begum
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Phase Change Material ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Storage System ◽  
Operating Conditions ◽  
Melting Time ◽  
Bottom Part ◽  
Change Material

This study reports on the unsteady two-dimensional numerical investigations of melting of a paraffin wax (phase change material, PCM) which melts over a temperature range of 8.7oC. The PCM is placed inside a circular concentric horizontal-finned annulus for the storage of thermal energy. The inner tube is fitted with three radially diverging longitudinal fins strategically placed near the bottom part of the annulus to accelerate the melting process there. The developed CFD code used in Tabassum et al., 2018 is extended to incorporate the presence of fins. The numerical results show that the average Nusselt number over the inner tube surface, the total melt fraction, the total stored energy all increased at every time instant in the finned annulus compared to the annulus without fins. This is due to the fact that in the finned annulus, the fins at the lower part of the annulus promotes buoyancy-driven convection as opposed to the slow conduction melting that prevails at the bottom part of the plain annulus. Fins with two different heights have been considered. It is found that by extending the height of the fin to 50% of the annular gap about 33.05% more energy could be stored compared to the bare annulus at the melting time of 82.37 min for the identical operating conditions. The effects of fins with different heights on the temperature and streamfunction distributions are found to be different. The present study can provide some useful guidelines for achieving a better thermal energy storage system.

Second-Law Analysis in a Steam Power Plant for Minimization of Avoidable Exergy Destruction

2010 ◽  
Author(s):  
Tapan K. Ray ◽  
Pankaj Ekbote ◽  
Ranjan Ganguly ◽  
Amitava Gupta
Keyword(s):  
Work Performance ◽  
Operating Conditions ◽  
Performance Criteria ◽  
Second Law ◽  
Feed Water ◽  
Exergy Destruction ◽  
Actual Performance ◽  
Time Operation ◽  
Major Equipment ◽  
Cycle Efficiency

Performance analysis of a 500 MWe steam turbine cycle is performed combining the thermodynamic first and second-law constraints to identify the potential avenues for significant enhancement in efficiency. The efficiency of certain plant components, e.g. condenser, feed water heaters etc., is not readily defined in the gamut of the first law, since their output do not involve any thermodynamic work. Performance criteria for such components are defined in a way which can easily be translated to the overall influence of the cycle input and output, and can be used to assess performances under different operating conditions. A performance calculation software has been developed that computes the energy and exergy flows using thermodynamic property values with the real time operation parameters at the terminal points of each system/equipment and evaluates the relevant rational performance parameters for them. Exergy-based analysis of the turbine cycle under different strategic conditions with different degrees of superheat and reheat sprays exhibit the extent of performance deterioration of the major equipment and its impact to the overall cycle efficiency. For example, during a unit operation with attemperation flow, a traditional energy analysis alone would wrongly indicate an improved thermal performance of HP heater 5, since the feed water temperature rise across it increases. However, the actual performance degradation is reflected as an exergy analysis indicates an increased exergy destruction within the HP heater 5 under reheat spray. These results corroborate to the deterioration of overall cycle efficiency and rightly assist operational optimization. The exergy-based analysis is found to offer a more direct tool for evaluating the commercial implication of the off-design operation of an individual component of a turbine cycle. The exergy destruction is also translated in terms of its environmental impact, since the irretrievable loss of useful work eventually leads to thermal pollution. The technique can be effectively used by practicing engineers in order to improve efficiency by reducing the avoidable exergy destruction, directly assisting the saving of energy resources and decreasing environmental pollution.

scholarly journals The Soil Organic Matter in Connection with Soil Properties and Soil Inputs

Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 779
Author(s):  
Václav Voltr ◽  
Ladislav Menšík ◽  
Lukáš Hlisnikovský ◽  
Martin Hruška ◽  
Eduard Pokorný ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Texture ◽  
Management Practices ◽  
Soil Depth ◽  
Operating Conditions ◽  
Hot Water ◽  
Natural Soil ◽  
Soil Productivity ◽  
Linear Regression Models

The content of organic matter in the soil, its labile (hot water extractable carbon–HWEC) and stable (soil organic carbon–SOC) form is a fundamental factor affecting soil productivity and health. The current research in soil organic matter (SOM) is focused on individual fragmented approaches and comprehensive evaluation of HWEC and SOC changes. The present state of the soil together with soil’s management practices are usually monitoring today but there has not been any common model for both that has been published. Our approach should help to assess the changes in HWEC and SOC content depending on the physico-chemical properties and soil´s management practices (e.g., digestate application, livestock and mineral fertilisers, post-harvest residues, etc.). The one- and multidimensional linear regressions were used. Data were obtained from the various soil´s climatic conditions (68 localities) of the Czech Republic. The Czech farms in operating conditions were observed during the period 2008–2018. The obtained results of ll monitored experimental sites showed increasing in the SOC content, while the HWEC content has decreased. Furthermore, a decline in pH and soil´s saturation was documented by regression modelling. Mainly digestate application was responsible for this negative consequence across all soils in studied climatic regions. The multivariate linear regression models (MLR) also showed that HWEC content is significantly affected by natural soil fertility (soil type), phosphorus content (−30%), digestate application (+29%), saturation of the soil sorption complex (SEBCT, 21%) and the dose of total nitrogen (N) applied into the soil (−20%). Here we report that the labile forms (HWEC) are affected by the application of digestate (15%), the soil saturation (37%), the application of mineral potassium (−7%), soil pH (−14%) and the overall condition of the soil (−27%). The stable components (SOM) are affected by the content of HWEC (17%), soil texture 0.01–0.001mm (10%), and input of organic matter and nutrients from animal production (10%). Results also showed that the mineral fertilization has a negative effect (−14%), together with the soil depth (−11%), and the soil texture 0.25–2 mm (−21%) on SOM. Using modern statistical procedures (MRLs) it was confirmed that SOM plays an important role in maintaining resp. improving soil physical, biochemical and biological properties, which is particularly important to ensure the productivity of agroecosystems (soil quality and health) and to future food security.

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