Validation of a simple dynamic thermal performance characterization model based on the piston flow concept for flat-plate solar collectors

Yang, Ming; Ma, Rongjiang; Zhu, Xiaoguang; Fan, Jianhua; Yuan, Guofeng; Wang, Zhifeng

doi:10.1016/j.solener.2016.09.040

Cited by 10 publications

(5 citation statements)

References 18 publications

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“…A solution to this problem involves their conversion to a transfer function form using the Laplace transform. An analysis of the transient states of the collector using the Laplace transform was used both for the HWB equation [21], its numerous modifications [31][32][33][34][35][36], as well as collector models based on innovative concepts, e.g., piston flow [37,38]. Models belonging to this group are usually used to simulate the operation of existing solar collectors.…”

Section: An Overview Of Test Methods For Flat-plate Solar Collectorsmentioning

confidence: 99%

Comparison of Solar Collector Testing Methods—Theory and Practice

2020

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One of the most important problems of operating solar heating systems involves variable efficiency depending on operating conditions. This problem is more pronounced in hybrid energy systems, where a solar installation cooperates with other segments based on conventional carriers of energy or renewable sources of energy. The operating cost of each segment of a hybrid system depends mainly on the resulting efficiency of solar installation. For over 40 years, the procedures of testing solar collectors have been undergoing development, testing, comparison and verification in order to create a procedure that would allow determining the thermal behavior of a solar collector without performing expensive and complicated experimental tests, usually based on the steady state condition. The proper determination of the static and dynamic properties of a solar collector is of key significance, as they constitute a basis for the design of a solar heating installation, as well as a control system. It is therefore important to conduct simulating and operating tests enabling the performance of a comparative analysis intended to indicate the degree to which the static and dynamic properties of a solar collector depend on the method used for their determination. The paper compares the static and dynamic properties of a flat solar collector determined by means of various methods. Based on the produced results, it has been concluded that the static and dynamic properties of a collector determined using various methods may differ from each other even by 50%. This means that it is possible to increase the efficiency of a solar heating installation via the use of an adaptive control algorithm, enabling real-time calculation of the values of characteristic parameters of solar installation, e.g., the time constant under operating conditions.

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Section: An Overview Of Test Methods For Flat-plate Solar Collectorsmentioning

confidence: 99%

Comparison of Solar Collector Testing Methods—Theory and Practice

2020

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“…The adopted model assumptions imply that the transversal temperature gradients in each layer are negligible compared to the longitudinal ones [25,34]. In addition, in order to support this assumption, the Biot number [35] is also calculated for both glass cover and bottom aluminum substrate, considering the typical operation conditions of the collector.…”

Section: Numerical Model Of the Collectormentioning

confidence: 99%

Experimental and Numerical Analyses of a Flat Plate Photovoltaic/Thermal Solar Collector

2017

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This paper presents a one-dimensional finite-volume model of an unglazed photovoltaic/thermal (PVT) solar collector. The unit consists of a conventional solar photovoltaic (PV) collector coupled with a suitable heat exchanger. In particular, the collector includes a roll bond heat exchanger and it is not equipped with back and frame insulation. The system is discretized along the flow direction (longitudinal) of the cogenerative collector. For each finite-volume element of the discretized computational domain, mass and energy balances are implemented. The collector geometry and materials parameters are taken from a commercially available device. An on-field experimental investigation is performed in order to validate the proposed model. The model is used to evaluate both electrical and thermodynamic parameters for each element of the domain and for fixed operating conditions. Finally, a sensitivity analysis is also performed in order to investigate the energetic performance of the cogenerative collector as a function of the main design/environmental parameters.

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“…An increase in temperature of 1°C in photovoltaic will result in a decrease in electrical efficiency of 0.5% [2,3]. The reduction in excessive heat temperature in photovoltaics will result in high electrical efficiency [4,5].…”

Section: Introductionmentioning

confidence: 99%

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2022

Jurnal Polimesin

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The sun is a renewable energy source that has several advantages such as being easy to obtain, free of pollution, and available in sufficient quantities. The heat energy received by the photovoltaic can cause an increase in surface temperature, resulting in a decrease in electrical efficiency. One of the efforts to increase photovoltaic electrical efficiency is using air cooling, by adding absorber fins or thermal photovoltaic (PV/T). The lapping type fin has superior performance in reducing the temperature of the PV module compared to the linear (conventional) fin type. The purpose of this study was to compare the performance of thermal PV using conventional fins with lapping segmentation fins carried out using the CFD approach using ANSYS Fluent. The simulation test procedures include: making linear fin geometry (conventional), linear lapping and segmentation lapping, conducting mesh quality studies, and determining boundary conditions and modeling parameters. Modeling variations in the direction of airflow 0°, 15°, 30°, 45°, 60°, 75°, and 90°. The numerical simulation results show that the use of segmented lapping fins can reduce the PV surface temperature by 1.79 °C or about 4.11% compared to conventional (linear) lapping in the airflow direction of 90º (parallel to the fins). The results of this study support the use of integrated PV and passive cooling systems to reduce efficiency losses in actual conditions, where there is a multidirectional airflow characteristic, which may not be advantageous for conventional heatsinks.

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Validation of a simple dynamic thermal performance characterization model based on the piston flow concept for flat-plate solar collectors

Cited by 10 publications

References 18 publications

Comparison of Solar Collector Testing Methods—Theory and Practice

Comparison of Solar Collector Testing Methods—Theory and Practice

Experimental and Numerical Analyses of a Flat Plate Photovoltaic/Thermal Solar Collector

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