Thermal performance optimization of a parabolic trough collector operating with various working fluids using copper nanoparticles.

2021 ◽  
pp. 1-35
Author(s):  
Yasser M. Abdullatif ◽  
Eric Chekwube Okonkwo ◽  
Tareq Al-Ansari
Keyword(s):  
Copper Nanoparticles ◽  
Thermal Performance ◽  
Performance Optimization ◽  
Volume Flow Rate ◽  
Liquid Sodium ◽  
Working Fluid ◽  
Inlet Temperature ◽  
Parabolic Trough ◽  
Pressurized Water ◽  
Working Fluids

Abstract This study presents a thermal performance comparison of various working fluids in Parabolic Trough Collectors. Fluids such as gases (helium, carbon dioxide, and air), liquid sodium, and liquids (pressurized water, Therminol VP1, Syltherm 800) are evaluated. This study also examines the efficiency enhancement obtained from the dispersion of copper nanoparticles in water, Therminol-VP1, and Syltherm 800 base fluids. The optimum parameters for nanoparticle concentration, volume flow rate, and inlet temperature to obtain the maximum efficiencies for each working fluid were evaluated in this study. The thermal model used in this study was modelled after the commercially available LS-2 collector, which was designed in the engineering equation solver (EES) and validated with results found in literature. The results of the study show that the Cu/Syltherm 800 nanofluid showed the most enhancement in thermal efficiency with 0.62% while Cu/water and Cu/Therminol VP1 had enhancements of 0.3% and 0.2% respectively.

Analysis of Electric Performance and Optimization of Trough Concentrating Solar Thermoelectric Cogeneration System

2013 ◽  
Vol 368-370 ◽  
pp. 1209-1213
Author(s):  
Zhi Ping Chen ◽  
Ming Li ◽  
Xu Ji ◽  
Xi Luo
Keyword(s):  
Heat Transfer ◽  
Thermal Performance ◽  
Performance Optimization ◽  
Heat Transfer Process ◽  
Working Fluid ◽  
Transfer Model ◽  
Experimental Basis ◽  
Parabolic Trough ◽  
One Dimensional ◽  
Cogeneration System

This study introduced the basic situation of the parabolic trough concentrating solar cogeneration system, and set a one-dimensional steady-state mathematical heat transfer model based on the experimental devices, at the same time clarified influencing factors of the major heat transfer process and thermal performance of the system. The article did perspectives theoretical analysis and simulation for the system in different aspects, through using of solar trough concentrator reflecting device, established thermal performance experiments that water as the working fluid flow, provided theoretical and experimental basis for the thermal performance optimization of the system.

scholarly journals Thermal Assessment of Selective Solar Troughs

Energies ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 3130
Author(s):  
Shahzada Zaman Shuja ◽  
Bekir Sami Yilbas ◽  
Hussain Al-Qahtani
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Thermal Performance ◽  
Working Fluid ◽  
Second Law ◽  
Inlet Temperature ◽  
Pressurized Water ◽  
Pressure Drops ◽  
Fluid Mass

A comparative study was carried out incorporating a novel approach for thermal performance evaluations of commonly used parabolic trough collectors, namely the Euro, Sky, and Helio troughs. In the analysis, pressurized water and therminol-VP1 (eutectic mixture of diphenyl oxide (DPO) and biphenyl) fluid were introduced as working fluids, and the governing equation of energy was simulated for various working fluid mass flow rates and inlet temperatures. The thermal performance of the troughs was assessed by incorporating the first- and second-law efficiencies and by using temperature increases and pressure drops of the working fluid. It was found that the first-law efficiency of the troughs increased with the working fluid mass flow rate, while it decreased with an increasing working fluid inlet temperature. The first-law efficiency remained the highest for the Euro trough, followed by the Sky and Helio troughs. The second-law efficiency reduced with an increasing working fluid mass flow rate, while it increased with an increasing working fluid inlet temperature. The second-law efficiency became the highest for the Helio Trough, followed by the Sky and Euro troughs. The temperature increase remained the highest along the length of the receiver for the Helio Trough compared to that corresponding to the Euro and Sky troughs for the same mass flow rate of the working fluid. The pressure drops in the working fluid became high for the Euro Trough, followed by the Sky and Helio troughs. The pressurized water resulted in higher second-law efficiency than the therminol-VP1 fluid did for all of the troughs considered.

Performance Optimization and Economic Analysis of Geothermal Power Generation by Subcritical and Supercritical Organic Rankine Cycles

2016 ◽  
Author(s):  
Changwei Liu ◽  
Tieyu Gao ◽  
Jiangnan Zhu ◽  
Jiamin Xu
Keyword(s):  
Economic Analysis ◽  
Power Output ◽  
Performance Optimization ◽  
Supercritical Condition ◽  
Working Fluid ◽  
Outlet Temperature ◽  
Working Fluids ◽  
Turbine Inlet ◽  
Net Power Output ◽  
Subcritical Condition

In a sustainability context, using renewable energy sources to hedge against increasing consumption of fossil fuels and reduce greenhouse gas emissions becomes increasingly important. The geothermal resource has a great application prospect due to its rich reserves and convenient utilization, and Organic Rankine Cycle (ORC) is a effective method to convert the low-grade geothermal to electricity. To improve the performance of geothermal ORC system, working fluid selection, system parameter optimization and the cycle design are the main approaches. Zeotropic mixtures may show superiority as ORC working fluids due to the temperature glides during the phase transitions, which leads to better temperature matches between the working fluid and the heat source/sink. Moreover, owing to the changing temperature during the transition from liquid to vapor in the vapor generator, supercritical ORC provides a great potential in geothermal utilization and irreversibility reduction. This paper displays an investigation on the performance optimization and economic analysis of various working fluids under subcritical and supercritical conditions. To avoid the silica oversaturation, the geothermal water reinjection temperature should not be less than 70 °C. Turbine inlet temperature, condenser outlet temperature as well as turbine inlet pressure (for supercritical ORC) are optimized to maximize the net power output. Moreover, economic analysis is conducted by taking heat exchanger area per unit power output (APR) and the specific investment cost (SIC) as indicators under the optimal net power output condition. The results shows that working fluid with a medium critical temperature yields greater net power output in supercritical ORC and mixture produces larger net power output compared with its pure components in subcritical ORC. Compared with isobutane (R600a) under subcritical condition, isobutane/isopentane (R600a/R601a) and isobutane/pentane (R600a/R601) under subcritical condition, R134a and R1234ze(E) under supercritical condition yield 3.9%, 3.8%, 8.5% and 8.8% more net power outputs, respectively. In addition, R600a/R601a and R600a/R601 under subcritical condition own higher APR and SIC while R134a and R1234ze(E) under supercritical condition possess lower APR and SIC.

Optimum geometry of parabolic trough collectors with optical and thermal criteria

2017 ◽  
Vol 8 (1) ◽  
pp. 45-50 ◽  
Author(s):  
S. Pavlovic ◽  
E. Bellos ◽  
V. Stefanovic ◽  
C. Tzivanidis
Keyword(s):  
Steady State ◽  
Optimum Design ◽  
Thermal Performance ◽  
Focal Length ◽  
Flow Simulation ◽  
Inlet Temperature ◽  
Exergetic Efficiency ◽  
Parabolic Trough ◽  
Optimum Geometry ◽  
The Impact

The objective of this work is to investigate the impact of the geometric dimensions of parabolic trough collector (PTC) in the optical, energetic and exergetic efficiency. The module of the commercial LS-3 PTC is examined with SOLIDWORKS FLOW SIMULATION in steady-state conditions. Various combinations of reflector widths and receiver diameters are tested. The optical and the thermal performance, as well as the exergetic performance are calculated for all the examined configurations. According to the final results, higher widths demands higher receiver diameter for optimum performance. For inlet temperature equal to 200 °C, the optimum design was find to be 3000 mm width with 42.5 mm receiver diameter, with the focal length to be 1840 mm (this is kept constant in all the cases). The results of this work and the presented methodology can be used as guidelines for the design of optimum PTC in the future.

Novel Parabolic Trough Collectors Driving a Small-Scale Organic Rankine Cycle System

2007 ◽  
Author(s):  
P. Kohlenbach ◽  
S. McEvoy ◽  
W. Stein ◽  
A. Burton ◽  
K. Wong ◽  
...  
Keyword(s):  
Steel Substrate ◽  
Low Cost ◽  
Sheet Steel ◽  
Organic Rankine Cycle ◽  
Glass Tube ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Small Scale ◽  
Inlet Temperature ◽  
Parabolic Trough

This paper presents component performance results of a new parabolic trough collector array driving an organic Rankine cycle (ORC) power generation system. The system has been installed in the National Solar Energy Centre at CSIRO Energy Technology in Newcastle, NSW, Australia. It consists of four rows of 18 parabolic mirrors each in a 2×2 matrix with a total aperture area of approximately 132m2. The absorber tube is a laterally aligned, 40mm copper tube coated with a semi-selective paint and enclosed in a 50mm non-evacuated glass tube to reduce convection losses. The mirror modules, which are light-weight and robust, are made from thin low iron back silvered glass bonded to a sheet steel substrate. They are supported by a box truss on semi circular hoops running on rollers for single axis tracking. The mirror design has been chosen to allow low-cost manufacturing as well as simple commissioning and operation. The ORC unit is a FP6 unit sourced from Freepower Ltd. with a net power output of 6kWel at 180°C inlet temperature and a total heat input of 70 kWth. It uses a two-stage expansion process with hydrofluoroether as the working fluid. A wet cooling tower is used to dissipate the reject heat from the ORC. The two key components of the envisioned system are the trough reflector/receiver and the ORC unit. The optical performance of the mirror elements was investigated with regard to the flux mapping onto the receiver tube. The ORC unit has been tested separately using an electrical oil heater as the heat source. This paper presents results for irradiation capture and intensity over the receiver width of a single trough mirror module. The complete system including trough collectors and ORC has not been in transient operation yet, thus experimental steady-state results of the ORC unit are presented.

Thermal Performance Intensification of Car Radiator using SiO2/Water and ZnO/Water Nanofluids

2021 ◽  
pp. 1-25
Author(s):  
Hussein Maghrabie ◽  
Hamouda Mousa
Keyword(s):  
Heat Transfer ◽  
Working Conditions ◽  
Flow Rate ◽  
Thermal Performance ◽  
Cooling System ◽  
Volume Flow Rate ◽  
Volume Flow ◽  
Coolant Temperature ◽  
Inlet Temperature ◽  
The Impact

Abstract Recent progress in nanotechnology has lead to a revolution in the automotive cooling system. In the present work, enhancement of car radiator thermal performance was investigated using different nanofluids named SiO2/water, ZnO/water nanofluids as cooling mediums. The present study mainly aims to investigate the impact of (5 wt.%) from SiO2 and ZnO nanoparticles (NPs) dispersed in water based on car radiator heat transfer with spherical and hexagonal morphology, respectively. The experiments were performed in two working conditions of the nanofluids i.e coolant temperature and volume flow rate, moreover the present results were compared with the previous studies. The experimental working conditions were set at coolant inlet temperature (tc,i) ranged from 45 oC to 80 oC and the coolant volume flow rate (V) ranged from 3.5 lit/min to 6.5 lit/min. The experimental results show that the hexagonal ZnO/water nanofluid was superior towards enhancement of car radiator thermal performance comparing to that of SiO2 NPs. Additionally, at 6.5 lit/min and 45 °C, the enhancements of car radiator effectiveness due to using SiO2 and ZnO based water nanofluids and compared with that for the based water were 13.9% and 16%, respectively. The present study used the multiple regression analysis (MRA) and hence empirical correlations are suggested to estimate the overall heat transfer coefficient (U) for all coolants as functions of volume flow rate (V) and the coolant inlet temperature (tc,i) with a maximum STDEV of ± 1.85%.

scholarly journals Thermal Performance Analysis of the Charging/Discharging Process of a Shell and Horizontally Oriented Multi-Tube Latent Heat Storage System

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6193
Author(s):  
Mohamed Fadl ◽  
Philip Eames
Keyword(s):  
Latent Heat ◽  
Flow Rate ◽  
Thermal Performance ◽  
Thermal Energy ◽  
Volume Flow Rate ◽  
Storage System ◽  
Volume Flow ◽  
Hot Water ◽  
Working Fluid ◽  
Heat Demand

In this study, the thermal performance of latent heat thermal energy storage system (LHTESS) prototype to be used in a range of thermal systems (e.g., solar water heating systems, space heating/domestic hot water applications) is designed, fabricated, and experimentally investigated. The thermal store comprised a novel horizontally oriented multitube heat exchanger in a rectangular tank (forming the shell) filled with 37.8 kg of phase change material (PCM) RT62HC with water as the working fluid. The assessment of thermal performance during charging (melting) and discharging (solidification) was conducted under controlled several operational conditions comprising the heat transfer fluid (HTF) volume flow rates and inlet temperatures. The experimental investigations reported are focused on evaluating the transient PCM average temperature distribution at different heights within the storage unit, charging/discharging time, instantaneous transient charging/discharging power, and the total cumulative thermal energy stored/released. From the experimental results, it is noticed that both melting/solidification time significantly decreased with increase HTF volume flow rate and that changing the HTF inlet temperature shows large impacts on charging time compared to changing the HTF volume flow rate. During the discharging process, the maximum power output was initially 4.48 kW for HTF volume flow rate of 1.7 L/min, decreasing to 1.0 kW after 52.3 min with 2.67 kWh of heat delivered. Based on application heat demand characteristics, required power levels and heat demand can be fulfilled by employing several stores in parallel or series.

The Effect of Material Properties on the Thermal Efficiency of the Minto Solar Wheel

1980 ◽  
Vol 102 (2) ◽  
pp. 504-507 ◽  
Author(s):  
S. Lin ◽  
R. Bhardwaj
Keyword(s):  
Thermal Performance ◽  
Thermal Efficiency ◽  
Material Properties ◽  
Working Fluid ◽  
Working Fluids ◽  
Mean Diameter ◽  
The Mean ◽  
The Ideal

The characteristic of the thermal performance of the Minto solar wheel is that its thermal efficiency is strongly dependent on the material properties of the working fluid. For a specified working fluid, the thermal efficiency of the ideal cycle of the Minto solar wheel is dependent only on the mean diameter of the wheel. To study the effect of the material properties of the working fluid on the ideal thermal efficiency, 14 working fluids are selected, and their thermal efficiencies as functions of the mean diameter of the wheel are calculated and compared with each other. Among these fluids, R-12, R-115, R-500, R-22 and R-13B1 achieve better thermal performance than the others.

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