Flat plate thermal solar collector efficiency: Transient behavior under working conditions. Part I: Model description and experimental validation

Rodríguez-Hidalgo, M.C.; Rodríguez-Aumente, P.A.; Lecuona, A.; Gutiérrez-Urueta, G.; Ventas, R.

doi:10.1016/j.applthermaleng.2011.04.003

Cited by 81 publications

(21 citation statements)

References 38 publications

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“…Among the research models, previous works have also proposed an overall heat loss coefficient and experimental generalized correlations as complements to determine the solar collector's efficiency [6][7][8][9]. However, these proposed models generally use a fixed inclination with respect to the N-S horizontal axis, according to the latitude of the evaluation place [10,11], thereby disregarding the fact that the second and third coefficients of the efficiency curve are functions of the U L .…”

Section: Introductionmentioning

confidence: 99%

The Effect of the Angle of Inclination on the Efficiency in a Medium-Temperature Flat Plate Solar Collector

Orlando

Flores-Prieto

2017

Energies

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Abstract:In this experimental work, the effects of the inclination angle β and the (T i − T a )/G on the efficiency and the U L -value were investigated on a medium-temperature flat plate solar collector. The experiments were based on steady-state energy balance, by heat flow calorimetry at indoor conditions and considering the standard American National Standard Institute/American Society of Heating Refrigerating and Air Conditioning Engineers (ANSI/ASHRAE) 93-2010. The solar radiation was emulated by the Joule effect using a proportional integral derivative (PID) control considering two conditions of the absorber temperature, Case 1: ) vs. β were 8.0% at the horizontal position for Case 1, while for Case 2, the maximum change was 1.8% only. Therefore, the changes of the inclination angle cause significant variations of the convective flow patterns within the collector, which leads to considerable variation of the collector efficiency and its U L value.

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Section: Introductionmentioning

confidence: 99%

The Effect of the Angle of Inclination on the Efficiency in a Medium-Temperature Flat Plate Solar Collector

Orlando

Flores-Prieto

2017

Energies

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“…(7)). However, this latter method does not give an accurate indication of the real solar loop performance as stated in studies by Rodruguez-Hidalgo, Rodríguez-Aumente, Lecuona, Gutiérrez-Urueta, Ventas [22] and Sabatelli, Marano, Braccio, Sharma [23]; therefore, the results obtained by the ISO standard and by the direct method differ in most cases. The standard method can be used for evaluation of the solar collectors' performance in a steady-state condition, while in a transient condition the direct method is more appropriate for the efficiency calculation.…”

Section: Resultsmentioning

confidence: 70%

“…In the research, only the solar radiation data above 400 Wm -2 have been considered. As stated by researchers [22,23], using the lower solar radiation data for the efficiency calculations gives an inaccurate evaluation of the system's performance.…”

Section: Resultsmentioning

confidence: 99%

Thermal Performance Analysis of Solar Collectors Installed for Combisystem in the Apartment Building

Žandeckis¹,

Timma²,

Blumberga³

et al. 2012

Latvian Journal of Physics and Technical Sciences

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The paper focuses on the application of wood pellet and solar combisystem for space heating and hot water preparation at apartment buildings under the climate of Northern Europe. A pilot project has been implemented in the city of Sigulda (N 57° 09.410 E 024° 52.194), Latvia. The system was designed and optimised using TRNSYS − a dynamic simulation tool. The pilot project was continuously monitored. To the analysis the heat transfer fluid flow rate and the influence of the inlet temperature on the performance of solar collectors were subjected. The thermal performance of a solar collector loop was studied using a direct method. A multiple regression analysis was carried out using STATGRAPHICS Centurion 16.1.15 with the aim to identify the operational and weather parameters of the system which cause the strongest influence on the collector's performance. The parameters to be used for the system's optimisation have been evaluated.

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“…For the controller design, a mathematical model is created by performing an energy balance in each solar collector and in the generator. Equation (1) shows the output temperature T S of the generator with regard to time [50]. This dynamic equation is maintained as a function of the working fluid mass flowṁ of each solar collector, considering constant properties as the density ρ f = 998.2 kg/m 3 , specific heat C p f = 4182 j/kg K and the tank volume ∀ T = 0.180 m 3 .…”

Section: Layer 1: Fuzzy Control Of Solar Collector Systemmentioning

confidence: 99%

Smart Control System to Optimize Time of Use in a Solar-Assisted Air-Conditioning by Ejector for Residential Sector

et al. 2018

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Abstract:The present work provides a series of theoretical improvements of a control strategy in order to optimize the time of use of solar air-conditioning by an ejector distributed in multiple solar collectors of vacuum tubes for the residential sector, which will allow us to reduce carbon-dioxide emissions, costs and electrical energy consumption. In a solar ejector cooling system, the instability of the solar source of energy causes an operational conflict between the solar thermal system and ejector cooling cycle. A fuzzy control structure for the supervisory ejector cycle and multi-collector control system is developed: the first control is applied to control the mass flow of the generator and the evaporator for different cooling capacities (3, 3.5, 4, 4.5 and 5 kW) and set a temperature reference according to the operating conditions; the second is applied to keep a constant temperature power source that feeds the low-grade ejector cooling cycle using R134aas refrigerant. For the present work, the temperature of the generator oscillates between 65 • C and 90 • C, a condenser temperature of 30 • C and an evaporator temperature of 10 • C. For the purpose of optimization, there are different levels of performance for time of use: the Mode 0 (economic) gives a performance of 17.55 h, Mode 5 (maximum cooling power) 14.86 h and variable mode (variable mode of capacities) 16.25 h, on average. Simulations are done in MATLAB-Simulink applying fuzzy logic for a mathematical model of the thermal balance. They are compared with two different types of solar radiation: real radiation and disturbed radiation.

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Flat plate thermal solar collector efficiency: Transient behavior under working conditions. Part I: Model description and experimental validation

Cited by 81 publications

References 38 publications

The Effect of the Angle of Inclination on the Efficiency in a Medium-Temperature Flat Plate Solar Collector

The Effect of the Angle of Inclination on the Efficiency in a Medium-Temperature Flat Plate Solar Collector

Thermal Performance Analysis of Solar Collectors Installed for Combisystem in the Apartment Building

Smart Control System to Optimize Time of Use in a Solar-Assisted Air-Conditioning by Ejector for Residential Sector

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