scholarly journals Experimental investigation of dehumidification process regulated by the photo thermoelectric system

Author(s):  
Khalid Almutairi ◽  
Kashif Irshad ◽  
Salem Algarni ◽  
Amjad Ali ◽  
Saiful Islam

Abstract To decrease indoor relative humidity and have relaxing environments, small dehumidifiers are widely used in tropical climatic. Due to the benefits of eco-friendly, small size and silence operation, thermoelectric dehumidifier has gained interest but have limited practical application due to poor efficiency. Therefore, this study investigates the dehumidification characteristics of the thermoelectric module powered by a photovoltaic system for the production of fresh water under real climatic conditions. The performance of a novel prototype named as Photo Thermoelectric Dehumidifier (PVTE-D) was investigated both numerically and experimentally in different combinations of airflow rate and input power. The results obtained from the experiment suggested that the water condensate collection was increased by increasing the input power from a PV panel to the TE-D. In the month of May, the maximum water condensate collection of 1,852.3 mL/hr was attained at the input supply of 6 A and 5 V to the PVTE-D system. In the majority of cases, when the airflow rate is below 0.013 kg/s, maximum collections of water condensate have been achieved. This study provides a detailed understanding of the optimally suitable structural parameters of the PVTE-D under different operating conditions and reveals a novel configuration for higher water condensation capacity. HIGHLIGHT Thermoelectric module, photovoltaic, dehumidification, simulation, validation.

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Hafsa Abouadane ◽  
Abderrahim Fakkar ◽  
Benyounes Oukarfi

The photovoltaic panel is characterized by a unique point called the maximum power point (MPP) where the panel produces its maximum power. However, this point is highly influenced by the weather conditions and the fluctuation of load which drop the efficiency of the photovoltaic system. Therefore, the insertion of the maximum power point tracking (MPPT) is compulsory to track the maximum power of the panel. The approach adopted in this paper is based on combining the strengths of two maximum power point tracking techniques. As a result, an efficient maximum power point tracking method is obtained. It leads to an accurate determination of the MPP during different situations of climatic conditions and load. To validate the effectiveness of the proposed MPPT method, it has been simulated in matlab/simulink under different conditions.


Author(s):  
Qiang Cheng ◽  
Baobao Qi ◽  
Hongyan Chu ◽  
Ziling Zhang ◽  
Zhifeng Liu ◽  
...  

The combination of sliding/rolling motion can influence the degree of precision degradation of ball screw. Precision degradation modeling and factors analysis can reveal the evolution law of ball screw precision. This paper presents a precision degradation model for factors analysis influencing precision due to mixed sliding-rolling motion. The precision loss model was verified through the comparison of theoretical models and experimental tests. The precision degradation due to rolling motion between the ball and raceway accounted for 29.09% of the screw precision loss due to sliding motion. Additionally, the total precision degradation due to rolling motion accounted for 21.03% of the total sliding precision loss of the screw and nut, and 17.38% of the overall ball screw precision loss under mixed sliding-rolling motion. In addition, the effects of operating conditions and structural parameters on precision loss were analyzed. The sensitivity coefficients of factors influencing were used to quantitatively describe impact degree on precision degradation.


Author(s):  
Nikolaj Dobrzinskij ◽  
Algimantas Fedaravicius ◽  
Kestutis Pilkauskas ◽  
Egidijus Slizys

Relevance of the article is based on participation of armed forces in various operations and exercises, where reliability of machinery is one of the most important factors. Transportation of soldiers as well as completion of variety of tasks is ensured by properly functioning technical equipment. Reliability of military vehicles – armoured SISU E13TP Finnish built and HMMWV M1025 USA built were selected as the object of the article. Impact of climatic conditions on reliability of the vehicles exploited in southwestern part of the Atlantic continental forest area is researched by a case study of the vehicles exploitation under conditions of the climate of Lithuania. Reliability of military vehicles depends on a number of factors such as properties of the vehicles and external conditions of their operation. Their systems and mechanisms are influenced by a number of factors that cause different failures. Climatic conditions represent one of the factors of operating load which is directly dependent on the climate zone. Therefore, assessment of the reliability is started with the analysis of climatic factors affecting operating conditions of the vehicles. Relationship between the impact of climatic factors and failure flow of the vehicles is presented and discussed.


Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3863
Author(s):  
Tiago Alves ◽  
João Paulo N. Torres ◽  
Ricardo A. Marques Lameirinhas ◽  
Carlos A. F. Fernandes

The effect of partial shading in photovoltaic (PV) panels is one of the biggest problems regarding power losses in PV systems. When the irradiance pattern throughout a PV panel is inequal, some cells with the possibility of higher power production will produce less and start to deteriorate. The objective of this research work is to present, test and discuss different techniques to help mitigate partial shading in PV panels, observing and commenting the advantages and disadvantages for different PV technologies under different operating conditions. The motivation is to contribute with research, simulation, and experimental work. Several state-of-the-artsolutions to the problem will be presented: different topologies in the interconnection of the panels; different PV system architectures, and also introducing new solution hypotheses, such as different cell interconnections topologies. Alongside, benefits and limitations will be discussed. To obtain actual results, the simulation work was conducted by creating MATLAB/Simulink models for each different technique tested, all centered around the 1M5P PV cell model. The several techniques tested will also take into account different patterns and sizes of partial shading, different PV panel technologies, different values of source irradiation, and different PV array sizes. The results will be discussed and validated by experimental tests.


2013 ◽  
Vol 36 ◽  
pp. 479-487 ◽  
Author(s):  
F. Hannane ◽  
H. Elmossaoui ◽  
T.V. Nguyen ◽  
P. Petit ◽  
M. Aillerie ◽  
...  

2018 ◽  
Vol 7 (2.17) ◽  
pp. 70
Author(s):  
Jaiganesh K ◽  
Karuppiah N ◽  
Ravivarman S ◽  
Md Asif

The maximum electrical energy conversion efficiency of the Solar PV panel is up to 22% in normal conventional roof- top system under the temperature of 25˚C on Standard Test Condition (STC). In Indian climatic conditions, the atmospheric temperature is mostly above 35˚C to 45˚C, it incites 35˚C to 80˚C temperature on the PV panel. The black body of the PV panel absorbs more heat. This temperature affects the electrical efficiency of the panel significantly. This paper proposes the mathematical modelling of the solar PV panel for different solar irradiation and the temperature. The experimental evaluation is conducted in the latitude of 11.36 (N) and longitude 77.82 (E). The testing and monitoring was done with LabVIEW based National Instruments hardware such as NI cDAQ-9178, NI DAQ - 9227 and NI DAQ 9225. The comparative study between the simulated result and real time hardware results are discussed in this paper. The test result shows that the output of the proposed model mismatches with the experimental output of the solar PV panel due to the negative correlation between the efficiency and temperature for variable irradiation condition. It shows a power difference of 9.41W between the output of the proposed model and the experimental setup.  


Energies ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 582
Author(s):  
Holger Behrends ◽  
Dietmar Millinger ◽  
Werner Weihs-Sedivy ◽  
Anže Javornik ◽  
Gerold Roolfs ◽  
...  

Faults and unintended conditions in grid-connected photovoltaic systems often cause a change of the residual current. This article describes a novel machine learning based approach to detecting anomalies in the residual current of a photovoltaic system. It can be used to detect faults or critical states at an early stage and extends conventional threshold-based detection methods. For this study, a power-hardware-in-the-loop approach was carried out, in which typical faults have been injected under ideal and realistic operating conditions. The investigation shows that faults in a photovoltaic converter system cause a unique behaviour of the residual current and fault patterns can be detected and identified by using pattern recognition and variational autoencoder machine learning algorithms. In this context, it was found that the residual current is not only affected by malfunctions of the system, but also by volatile external influences. One of the main challenges here is to separate the regular residual currents caused by the interferences from those caused by faults. Compared to conventional methods, which respond to absolute changes in residual current, the two machine learning models detect faults that do not affect the absolute value of the residual current.


2013 ◽  
Vol 465-466 ◽  
pp. 211-215 ◽  
Author(s):  
Kashif Irshad ◽  
Khairul Habib ◽  
Nagarajan Thirumalaiswamy ◽  
Anas Elrayah Ahmed Elmahdi

The present study examines the performance of a single zone building integrated with PV Trombe wall (PV-TW) in term of thermal load reduction and electrical energy production by varying PV Glazing types (i.e. Single Glazing, Double glazing, Double glazing filled with gas (Argon)). TRNSYS software is used for simulation in which inputs like climatic conditions, building construction details, thermal properties of materials, detail of PV-TW and orientation of building is inserted. By comparing the results of all three types of glazing it is found that PV Double glazing filled with argon shows significant reduction in mean air duct temperature, hence reduces the PV cell temperature and increases power production of PV panel. Also solar radiation captured by massive wall of PV-TW is reduced by using PV Double glazing filled with argon as compared to other types of glazing, which further reduces thermal load inside the building.


2011 ◽  
Vol 250-253 ◽  
pp. 3228-3231 ◽  
Author(s):  
Da Hua Jiang ◽  
An Gui Li ◽  
Fa En Shi ◽  
Zhi Hua Wang

For particular commercial kitchen, using CFD software to build model according to the actual operation condition uttermost, adopting the exhaust system of up-suction hood, the effect of exhaust airflow rate on working temperature,velocity,CO2 concentration at main site in commercial kitchen is studied. According to the common four calculation methods of airflow rate of exhaust hood, the simulation results shows 4.81 m3/s of exhaust system can realize eliminating harmful gas quickly and effectively, IAQ is good relatively. Based on of it, additional airflow rate can not improve emissions effect and operating conditions obviously, whereas it can be detrimental to save energy. The simulation results help design exhaust system.


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