- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
A Detailed Optimisation of Solar Photovoltaic/Thermal Systems and its Application.
摘要： There have been various studies and experimental results analysing the operational behaviour of PVT, most of which has been done at steady state or quasi-state. Variable factors can be controlled to optimise the PVT output such as mass flow rate, irradiation falling on the PVT through tracking or incidence angles in a day and fixed factors that depend on the design of the chosen PVT system as well as location parameters such as ambient temperature, wind speed, Transport Fluid used, Difference in Structure, Packing Density, Nominal operating temperature, stagnation temperatures, Fill Factor, Thickness of each layer, Location and Latitude and Heat removal factor (harp or serpentine design). The aim of this research is to validate and predict the dynamic behaviour of PVT systems while accurately describing the factor responsible for the loss of efficiency at any point in time under various weather constraints. A commercial system was considered (Solar Angel PVT system) here and is simulated for an entire year. The system was modelled in MATLAB and solved in implicit RK-4 method. The research question finds out to establish the basis for a standard testing protocol for assessing PV-T performance throughout various differences. It also analyses the long-term dynamic performance of PV/T technology by providing evidential data analysis (solar irradiance, heat and electricity, ambient temperature, operational temperatures, flow rates and thermal storage capacity) while completing an assessment of PVT behaviour with respect to an equivalent PV under different weather conditions. The flow rates, heat removal factor and the location affect the thermal behaviour of the PV/T to a greater extent than nominal temperatures and stagnation temperatures.
关键词： Electric and Thermal Energy,Solar Photovoltaic thermal systems,Optimising,Solar Energy,Dynamic Modelling,Optimal operation of PVT,PVT systems with storage
更新于2025-09-12 10:27:22
-
Photovoltaic-thermal (PVT) technology: Review and case study
摘要： Nowadays, solar technology converts solar energy into electricity and heat separately. For electricity generation, the main obstacle is the fact that the photovoltaic cells produce less energy as the temperature increases. To overcome this, cooling techniques can be used to raise the efficiency of solar cells, in order to obtain greater power generation. The photovoltaic-thermal hybrid solar collector (or PVT) is an equipment that integrates a photovoltaic (PV) module, for the conversion of solar energy into electrical energy, and a module with high thermal conversion efficiency (T), which employs a thermal fluid. This optimization of solar conversion technology has the main objective of cooling the photovoltaic cells, for increased generation of electricity, while also resulting in useful thermal energy from the working fluid, therefore constituting a cogeneration equipment. The present work reviews the development and global panorama of PVT technology. Afterwards, a case study of a PVT system is presented, together with a theoretical and experimental study. A thermography analysis performed in this PVT system is also examined, which allows for a real-time study of its operating regimes in different conditions, mainly of its thermal behaviour, and for the diagnosis of hot spots that signal potential defects in the cells.
关键词： thermography analysis,Photovoltaic-thermal (PVT) technology,solar energy,hybrid solar collector
更新于2025-09-12 10:27:22
-
Energy and Exergy Analysis of Photovoltaic Thermal Air Collector Under Climatic Condition of North Eastern India
摘要： The performance of photovoltaic thermal (PVT) air collector has been studied in the climatic condition of North East, India theoretically and as the climatic condition of north east is different from the other zones of India. For this study, one of the city located in north eastern India named Silchar is chosen. Firstly, the validation of the theoretical model has been done with the experimental model of Agarwal and Tiwari (2012) which shows that theoretical model is in fair agreement with the experimental model as the correlation coefficient and root mean square percent deviation has been found as 0.94 and 9.1 %. The study is performed with three different values of mass flow rate (0.007 kg/s, 0.0097 kg/s and 0.0128 kg/s) for a typical day of December and March. It has been found that the maximum solar radiation has been achieved at 12.00 hr of the day for both the month under consideration. The nature of variation of solar cell temperature, back surface temperature, outlet air temperature, thermal and exergy gain throughout the day has been observed for different mass flow rates. It was reported from the study that the PVT air collector has better thermal performance for the mass flow rate of 0.0128 kg/s. For a mass flow rate of 0.0128 kg/s, it has been observed that for a typical day of December, the thermal energy gain and exergy gain has been achieved as152 Wh, and 7.88Wh, respectively, whereas for the month of March it has been observed as 185.15 Wh, and 17.82 Wh, respectively at 12.00 hr. Maximum outlet temperature has been obtained as 45°C, and 53°C, during winter (December) and summer (March), respectively. The exergy gain is found to enhance by almost 100% during summer than that of winter.
关键词： exergy,mass flow rate,solar radiation,energy,PVT air coolector
更新于2025-09-12 10:27:22
-
An algorithm for designing a cooling system for photovoltaic panels
摘要： Solar energy is an abundant source of energy for generating electricity. One of the main challenges in using solar energy is that solar photovoltaic (PV) panels are typically used in regions where solar radiation is high; consequently, the temperature of the panels will increase, and the efficiency of the panels will decrease. Adding cooling tubes to the PV panel is a possible approach to cool it down. To design such cooling systems, CFD simulations may be used; however, this approach tends to be time-consuming. In this paper, we report a new algorithm for designing straight cooling tubes. The algorithm can be used to determine important design parameters such as tube center-to-center length, diameter of the tube, and the minimum tube length needed to achieve a desired outlet temperature. The accuracy of the algorithm was tested using real-world data (including various ambient temperatures and solar radiations) and the maximum temperature difference between desired outlet temperature and CFD simulation for the designed cooling system was found to be 1.7oK.
关键词： Solar energy,Conjugated heat transfer,Design algorithm,Renewable energy,PVT,Cooling system
更新于2025-09-12 10:27:22
-
Characteristics analysis of the photovoltaic thermal heat pump system on refrigeration mode: An experimental investigation
摘要： Photovoltaic thermal heat pump technology stands for the combination of solar heat pump technology and a photovoltaic system, which has the characteristics of tri-generation (heating, cooling, and electricity) to meet the building's energy requirement. In this paper, the dual-use photovoltaic thermal heat pump system was used and investigated experimentally with an emphasis on the refrigeration mode, which with the feature of the novel roll-bond photovoltaic thermal unit working as condenser directly. Moreover, renewable energy such as solar radiation and long-wave radiation are the main energy source of this system. The experimental investigation of the system comprising; 4 roll-bond photovoltaic thermal units, 1 horsepower heat pump unit and 600 L ice storage tank was carried out. The performance evaluation method and uncertainty analysis of the system was proposed and implemented along with the examination on the refrigeration performance and operating characteristics of the system. The results indicate that the proposed photovoltaic thermal heat pump system can achieve the refrigeration for building space cooling demand in summer with high performance and long-term stable operation. This study could provide a valuable reference for the photovoltaic thermal heat pump multi-generation system design and large-scale practical application in northern China.
关键词： Photovoltaic thermal heat pump,Experimental study,Refrigeration performance,PVT,Operation characteristics
更新于2025-09-11 14:15:04
-
A comprehensive assessment of alternative absorber-exchanger designs for hybrid PVT-water collectors
摘要： In this paper, 26 alternative absorber-exchanger designs for hybrid PV-Thermal (PVT) solar collectors are proposed and compared against a reference-case, commercial sheet-and-tube PVT collector. The collectors involve different geometric design features based on the conventional sheet-and-tube configuration, and also on a newer flat-box structure constructed from alternative polymeric materials with the aim of maintaining or even improving heat transfer and overall (thermal and electrical) performance while achieving reductions in the overall weight and cost of the collectors. The main contributions of this research include: (i) the development and validation of a detailed 3-D computational finite-element model of the proposed PVT collector designs involving multi-physics processes (heat transfer, fluid dynamics and solid mechanics); (ii) results from comparative techno-economic analyses of the proposed PVT designs; and, (iii) further insights from thermal stress and structural deformation analyses of the proposed collectors, which are crucial for ensuring long lifetimes and especially important in the case of polymeric collectors. The results show that, in general, the flat-box designs (characterised by a thin absorber plate) are not sensitive to the flow-channel size or construction material, at least within the range of investigation. A PVT collector featuring a polycarbonate (PC) flat-box design with 3 × 2 mm rectangular channels appears to be a particularly promising alternative to commercial PVT collectors, achieving a slightly improved thermal performance compared to the reference case (with a 4% higher optical efficiency and 15% lower linear heat-loss coefficient), while also lowering the weight (by around 9%) and investment cost (by about 21%) of the collector. The structural analysis shows that the maximum von Mises stress experienced in the absorber-exchanger of the PC flat-box collector is considerably lower than that in the copper sheet-and-tube collector (< 13% vs. 64% of the material’s yield stress), which is attributed to the larger thermal expansion of the PC absorber-exchanger, that leads to lower stresses. Therefore, the proposed PC flat-box design is not expected to suffer higher strains than the commercially-available PVT collector.
关键词： Cost savings,Hybrid PVT collector,Solar energy,Efficiency,Absorber-exchanger,Structural analysis
更新于2025-09-10 09:29:36
-
Energy performance analysis of a novel solar PVT loop heat pipe employing a microchannel heat pipe evaporator and a PCM triple heat exchanger
摘要： This study presents a numerical analysis of the energy efficiency for a novel solar PVT Loop Heat Pipe (PVT-LHP) employing a novel Micro-channel evaporator and a novel PCM heat storage exchanger. It presents a description of the different sub-models in the PVT-LHP system (the PVT model, the microchannel heat collector model and the novel PCM triple heat exchanger model) and the integrated model of the system. The integrated model of the system was solved by ensuring a heat balance at the condenser and the evaporator. A parametric analysis has been performed in order to assess the influence of the environmental parameters (i.e. solar radiation, air temperature, wind velocity), structural parameters (i.e. glazing cover, the number of absorbing microchannel heat pipes, PV cell packing factor), the circulating fluid variables (i.e. cold-water inlet temperature and water mass flow rate) on the energy performance of the system. The novel PVT-LHP has been compared with a conventional Solar PVT-LHP system. It was found that lower solar radiation, lower ambient air temperature, higher wind speed, higher packing factor, lower cold-water inlet temperature and a smaller cover number led to an enhanced electrical efficiency, but a reduced thermal efficiency of the module; whereas a higher cold-water mass flow rate and a greater number of microchannel heat pipes gave rise to both thermal and electrical efficiencies of the module. It was also found that an increase of solar radiation, ambient temperature, cover number, microchannel heat pipe number and packing factor are favourable factors for the overall COP (Coefficient Of Performance) of the system, whereas an increase of wind velocity and cold water mass flow rate are unfavourable. The study indicated the existence of an optimal cover number, number of microchannel heat pipes and mass flowrate. Under the given design conditions, the electrical, thermal and overall efficiency of the PV/LHP module were 12.2 %, 55.6 % and 67.8% respectively and the novel system can achieve 28% higher overall energy efficiency and 2.2 times higher COP compared to a conventional system. The integrated computer model developed in this study can be used to design and optimize the novel PVT-LHP heating system.
关键词： microchannel,power supply,PVT,Loop Heat Pipe,PCM triple heat exchanger,heating
更新于2025-09-10 09:29:36