scholarly journals Air Flow Control of a Smart Electric Fan using IoT Solutions

Remote control of electric fans by the application of IoT technology addresses the restrictions of “push button” controls that are usual in conventional fans. This paper explains a new control method for air flow control of a Smart Electric Fan (SEF), in this case fans mainly used in the household. In this new method the supply voltage that is applied to the motor terminals of the SEF is precisely changed with the mobile application developed by using IoT solutions. As this proposed method integrates with the conventional control methods referred to as the Firing Angle Control method or Phase Angle Control method with a new IoT-based solution, the controlling of any device becomes simpler. We developed a mobile application that enables the fan to be remotely controlled using a smartphone or tablet computer. The phase or delay angle of the voltage waveform is changed by giving as an input from the smart phone mobile application, and this results in minimizing the power loss caused due to switching in case of push button system. We demonstrated that by using this app, implementing the IoT-based solution, the air flow rate of the SEF was increased and the performance of the SEF exceeded the air flow rate of the original, conventionally controlled fan with the speed of the fan being significantly increased. Applying this control method has thus been verified to be advantageous and appropriate for the remote control of the air flow and fan speed, resulting in the efficient Smart Electric Fan. The main focus of this research was to implement the integrated control method in the residential fans.

2015 ◽  
Vol 771 ◽  
pp. 137-140 ◽  
Author(s):  
Muhammad Miftahul Munir ◽  
Muhammad Sainal Abidin ◽  
Abdul Rajak ◽  
Khairurrijal

An airflow control system is one of important parts in the scanning mobility particle sizers system (SMPS) used in the field of aerosol and air filtration. In this paper, the air flow control system that consists of an air filter, a blower, an air flow sensor, a controller, and a computer are reported. A flow rate adjustment was performed by varying the rotation speed of the blower using a pulse width modulation (PWM) technique. The air flow sensor capable of measuring flow rate up to 20 liters / min was used to measure the air flow rate. In order to keep at a certain value of the flow rate, a proportional-integral-derivative (PID) control action was employed in which PID controller were manually tune. The results showed that the desired value of flow rate was quickly achieved with little overshoot was observed in the system output.


2015 ◽  
Vol 719-720 ◽  
pp. 376-380
Author(s):  
Xu Sheng Zhuo ◽  
Tong Li ◽  
Fan Yang ◽  
Dan Dan Wang

In combustion of a circulating fluidized bed, primary air plays a key role in keeping materials fluidized and regulating bed temperature. This report provides a design of reference governor for primary air fans to amend their control commands. That will improve the combustion efficiency via regulating primary air flow rate timely according to the changes of coal feed flow rate and bed temperature. To deal with the large inertia and slow response feature of primary air fans, a rule-based control method was used to design the reference governor. Based on the experiences of technical experts and operation data analysis, an expert rules system with wide coverage range was developed, which composed of the logical relationships between the coal feed flow rate, bed temperature and the primary air flow rate in various operation conditions. Test results show that designed reference governor can improve the control performance of primary air flow rate obviously.


2021 ◽  
pp. 174425912098418
Author(s):  
Toivo Säwén ◽  
Martina Stockhaus ◽  
Carl-Eric Hagentoft ◽  
Nora Schjøth Bunkholt ◽  
Paula Wahlgren

Timber roof constructions are commonly ventilated through an air cavity beneath the roof sheathing in order to remove heat and moisture from the construction. The driving forces for this ventilation are wind pressure and thermal buoyancy. The wind driven ventilation has been studied extensively, while models for predicting buoyant flow are less developed. In the present study, a novel analytical model is presented to predict the air flow caused by thermal buoyancy in a ventilated roof construction. The model provides means to calculate the cavity Rayleigh number for the roof construction, which is then correlated with the air flow rate. The model predictions are compared to the results of an experimental and a numerical study examining the effect of different cavity designs and inclinations on the air flow rate in a ventilated roof subjected to varying heat loads. Over 80 different test set-ups, the analytical model was found to replicate both experimental and numerical results within an acceptable margin. The effect of an increased total roof height, air cavity height and solar heat load for a given construction is an increased air flow rate through the air cavity. On average, the analytical model predicts a 3% higher air flow rate than found in the numerical study, and a 20% lower air flow rate than found in the experimental study, for comparable test set-ups. The model provided can be used to predict the air flow rate in cavities of varying design, and to quantify the impact of suggested roof design changes. The result can be used as a basis for estimating the moisture safety of a roof construction.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shahrbanoo Hamedi ◽  
M. Mehdi Afsahi ◽  
Ali Riahi-Madvar ◽  
Ali Mohebbi

AbstractThe main advantages of the dried enzymes are the lower cost of storage and longer time of preservation for industrial applications. In this study, the spouted bed dryer was utilized for drying the garden radish (Raphanus sativus L.) root extract as a cost-effective source of the peroxidase enzyme. The response surface methodology (RSM) was used to evaluate the individual and interactive effects of main parameters (the inlet air temperature (T) and the ratio of air flow rate to the minimum spouting air flow rate (Q)) on the residual enzyme activity (REA). The maximum REA of 38.7% was obtained at T = 50 °C and Q = 1.4. To investigate the drying effect on the catalytic activity, the optimum reaction conditions (pH and temperature), as well as kinetic parameters, were investigated for the fresh and dried enzyme extracts (FEE and DEE). The obtained results showed that the optimum pH of DEE was decreased by 12.3% compared to FEE, while the optimum temperature of DEE compared to FEE increased by a factor of 85.7%. Moreover, kinetic parameters, thermal-stability, and shelf life of the enzyme were considerably improved after drying by the spouted bed. Overall, the results confirmed that a spouted bed reactor can be used as a promising method for drying heat-sensitive materials such as peroxidase enzyme.


2001 ◽  
Author(s):  
T. Carlsson ◽  
A. Sokolov ◽  
A. Idebrant ◽  
M. Jirstrand

1979 ◽  
Vol 3 (6) ◽  
pp. 357-362
Author(s):  
H. C. Hewitt ◽  
E. I. Griggs

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