Design of an Innovative Solar Updraft Aeration System for Fish Ponds in the Developing World Using Thermofluidic Computational Modelling

2016 ◽  
Author(s):  
Ali Ebrahimi Khabbazi ◽  
Shakya Sur ◽  
Ahmed Mahmoud ◽  
Elan Pavlov ◽  
Amy M. Bilton
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Draft Tube ◽  
Solar Thermal ◽  
Fish Ponds ◽  
Resource Constrained ◽  
Aeration System ◽  
Convective Circulation ◽  
Patch Length

This paper introduces an innovative design concept for a low-cost solar-thermal aeration system for fish ponds which is amenable to implementation in resource-constrained settings. In its most basic form, the system consists of a metallic solar thermal collector and a heat transfer column (referred to as conduction element in this paper), which induces convective circulation by dissipating heat to the cooler, deeper layers of the pond. As a result of the circulation, oxygen generated by phytoplankton at the top of the pond is distributed throughout the water column, preventing oxygen losses to the atmosphere due to surface supersaturation and increasing the overall dissolved oxygen (DO) content in the pond. This paper presents a design study to evaluate different system configurations. Thermofluidic numerical models were implemented to systematically analyze and compare the mass flow rate through the draft tube induced by convection. Furthermore, parametric studies were performed to evaluate the effect of the insulation patch length and the aluminum plate thickness on the overall performance of the device (i.e. the induced mass flow rate through the draft tube). It was found that the two-fin configuration with split conduction elements was superior to the central rod design in terms of performance. In addition, it was found that depending on the insulation patch length, the induced mass flow rates can be increased up to 5 times. The results from the computational models indicate that the device can induce the convective circulation in order to improve the DO content at deep levels of the ponds and has potential to improve aquaculture productivity in resource-constrained settings. The results from this study will be used to configure systems for future field evaluations that will be performed in fish ponds in Bangladesh.

scholarly journals Solar Field Output Temperature Optimization Using a MILP Algorithm and a 0D Model in the Case of a Hybrid Concentrated Solar Thermal Power Plant for SHIP Applications

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3731
Author(s):  
Simon Kamerling ◽  
Valéry Vuillerme ◽  
Sylvain Rodat
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Solar Thermal ◽  
Outlet Temperature ◽  
Field Mass ◽  
Heat Demand ◽  
Process Heat ◽  
Solar Field ◽  
Control Trajectory

Using solar power for industrial process heat is an increasing trend to fight against climate change thanks to renewable heat. Process heat demand and solar flux can both present intermittency issues in industrial systems, therefore solar systems with storage introduce a degree of freedom on which optimization, on a mathematical basis, can be performed. As the efficiency of solar thermal receivers varies as a function of temperature and solar flux, it seems natural to consider an optimization on the operating temperature of the solar field. In this paper, a Mixed Integer Linear Programming (MILP) algorithm is developed to optimize the operating temperature in a system consisting of a concentrated solar thermal field with storage, hybridized with a boiler. The MILP algorithm optimizes the control trajectory on a time horizon of 48 h in order to minimize boiler use. Objective function corresponds to the boiler use, for completion of the heat from the solar field, whereas the linear constraints are a simplified representation of the system. The solar field mass flow rate is the optimization variable which is directly linked to the outlet temperature of the solar field. The control trajectory consists of the solar field mass flow rate and outlet temperature, along with the auxiliary mass flow rate going directly to the boiler. The control trajectory is then injected in a 0D model of the plant which performs more detailed calculations. For the purpose of the study, a Linear Fresnel system is investigated, with generic heat demand curves and constant temperature demand. The value of the developed algorithm is compared with two other control approaches: one operating at the nominal solar field output temperature, and the other one operating at the actual demand mass flow rate. Finally, a case study and a sensitivity analysis are presented. The MILP’s control shows to be more performant, up to a relative increase of the annual solar fraction of 4% at 350 °C process temperature. Novelty of this work resides in the MILP optimization of temperature levels presenting high non-linearities, applied to a solar thermal system with storage for process heat applications.

Experimental Investigation of a Flat Plate Photovoltaic/Thermal Collector

2018 ◽  
Author(s):  
Mohamad Modrek ◽  
Ali Al-Alili
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Power Output ◽  
Electrical Power ◽  
Solar Thermal ◽  
Pv Panel ◽  
Solar Thermal Collectors ◽  
Electrical Power Output ◽  
Electrical Output

Photovoltaic thermal collectors (PVT) combines technologies of photovoltaic panels and solar thermal collectors into a hybrid system by attaching an absorber to the back surface of a PV panel. PVT collectors have gained a lot of attention recently due to the high energy output per unit area compared to a standalone system of PV panels and solar thermal collectors. In this study, performance of a liquid cooled flat PVT collector under the climatic conditions of Abu Dhabi, United Arab Emirates was experimentally investigated. The electrical performances of the PVT collector was compared to that of a standalone PV panel. Moreover, effect of sand accumulation on performance of PVT collectors was examined. Additionally, effect of mass flow rate on thermal and electrical output of PVT collector was studied. Electrical power output is slightly affected by changes in mass flow rate. However, thermal energy increased by 22% with increasing flow rate. Electrical power output of a PV panel was found to be 38% lower compared to electrical output of PVT collectors. Dust accumulation on PVT surface reduced electrical power output up to 7% compared with a reference PVT collector.

scholarly journals Thermal Performance Comparison of Parabolic Trough Collector (PTC) Using Various Nanofluids

2021 ◽  
Vol 10 (4) ◽  
pp. 875-889
Author(s):  
Ashutosh Shirole ◽  
Mahesh Wagh ◽  
Vivek Kulkarni
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Thermal Efficiency ◽  
Power Plants ◽  
Large Scale ◽  
Solar Thermal ◽  
Pumping Power ◽  
Parabolic Trough ◽  
Parabolic Trough Collector

The objective of this paper is to investigate the theoretical performance of Parabolic Trough Collector (PTC) using various nanofluids. The theoretical performances are calculated for Al2O3, graphite, magnetite, SWCNH, CuO, SiO2, MWCNT, TiO2, Fe2O3, and ZnO in water nanofluids. The heat transfer equations, thermodynamic properties of nanofluid and pumping power are utilised for the development of novel thermal model.  The theoretical thermal efficiency of the PTC is calculated, and the economic viability of the technology is predicted for a range of nanofluid concentration. The results showed that the thermal conductivity increases with the concentration of nanoparticles in the base fluid. Magnetite nanofluid showed the highest thermal efficiency, followed by CuO, MWCNT, ZnO, SWCNH, TiO2, Fe2O3, Al2O3, graphite, and SiO2, respectively. The study reveals that MWCNT at 0.4% concentration is the best-suited nanofluid considering thermal gain and pumping power. Most of the nanofluids achieved optimum efficiency at 0.4% concentration. The influence of mass flow rate on thermal efficiency is evaluated. When the mass flow rate increased from 70 Kg/hr to 90Kg/hr, a 10%-20% efficiency increase is observed. Dispersing nanofluids reduces the levelized cost of energy of large-scale power plants. These findings add to the knowledge of the scientific community aimed explicitly at solar thermal energy technology. The report can also be used as a base to pursue solar thermal projects on an economic basis.

scholarly journals Experimental and Numerical Simulations Predictions Comparison of Power and Efficiency in Hydraulic Turbine

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Laura Castro ◽  
Gustavo Urquiza ◽  
Adam Adamkowski ◽  
Marcelo Reggio
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Draft Tube ◽  
Flow Simulation ◽  
Numerical Data ◽  
Hydroelectric Power Plant ◽  
Hydraulic Turbine ◽  
Hydroelectric Power ◽  
Spiral Case

On-site power and mass flow rate measurements were conducted in a hydroelectric power plant (Mexico). Mass flow rate was obtained using Gibson's water hammer-based method. A numerical counterpart was carried out by using the commercial CFD software, and flow simulations were performed to principal components of a hydraulic turbine: runner and draft tube. Inlet boundary conditions for the runner were obtained from a previous simulation conducted in the spiral case. The computed results at the runner's outlet were used to conduct the subsequent draft tube simulation. The numerical results from the runner's flow simulation provided data to compute the torque and the turbine's power. Power-versus-efficiency curves were built, and very good agreement was found between experimental and numerical data.

The standard unit mass flow rate of gas-liquid mixtures

2020 ◽  
pp. 13-16
Author(s):  
V.N. Petrov ◽  
◽  
V.F. Sopin ◽  
L.A. Akhmetzyanova ◽  
Ya.S. Petrova ◽  
...  
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Liquid Mixtures ◽  
Unit Mass ◽  
Standard Unit

Prediction of Leakage Mass Flow Rate Through Gas Springs

1987 ◽  
Author(s):  
Roberto Bruno Bossio ◽  
Vincenzo Naso ◽  
Marian Cichy ◽  
Boleslaw Pleszewski
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate
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