International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395 -0056
Volume: 04 Issue: 01 | Jan -2017
p-ISSN: 2395-0072
www.irjet.net
A Time Sharing Scheme for Room Ventilation Control using a Smart Sensing Actuator R.Raja Prabhu1, R.Sreevidya2 1Assistant
Professor, Dept of Electrical and Electronics Engineering, Imayam College of Engineering, Trichy, Tamilnadu, India, rajaprabhuae@gmail.com 2Assistant Professor, Dept of Electrical and Electronics Engineering, TRP Engineering College, Trichy, Tamilnadu, India, sreevidya202@gmail.com
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Abstract - This paper proposes a system that acts as a mechanism for room ventilation control in a time-sharing manner by using a self sensing actuator. The ventilation fan alone cannot be used as the actuator and sensor. It can be used in a time sharing manner. Generally the motors and actuators contain internal feedback. The motors function as a generators, and actuators generate normally a force is applied to them. This implies a reversible process mechanism. The function of a ventilation fan was obtained by analyzing the automatic control by using the ventilation system in the sealed house. The change in pressure in between the inner and outer portion of the room due to exhaust, the high sensing actuator will act as a power generator from which the motor generates a voltage. The main power scheme was mentioned below: when the voltage from the sensing fan, which is at a standstill, exceeds a threshold value, the ventilation fan starts rotating for a short period of time and comes to idle position mode to observe the pressure. These processes are repeated again and again. A ventilation fan with the area of 0.25 m acts as a high sensitive gauge pressure sensor at pressure up to 3.0 Pa, with the frequency range of 0.2 Hz. The controller which turns the ventilation fan on when the pressure exceeds 3.5 Pa for 12 s and returns it to standstill mode worked well in an actual airtight room.
Key Words: Actuator, Time sharing, sensitive pressure sensor, Ventilation fan, Reversible Process.
placed in another room where the doors are closed, or someone closes the hole to stop hot or cold air from entering. In such cases, the pressure in the house may fall by 10 Pa, and the door may be difficult to open owing to the negative pressure. In addition, because of the poor aeration owing to the negative pressure, the air is not ventilated even if the aeration fan works properly. Most people believe that the room is ventilated if they hear the sound of the aeration fan; however, this may not be the case. At worst, this could cause carbon monoxide poisoning. The kitchens of newly built buildings have both an aeration fan and an exhaust fan, some of which work simultaneously but most of which are independent, because if a kitchen window is open, the exhaust fan does not need to be on. Similarly, ventilation in many kitchens in restaurants is dangerous or ineffective.
This paper describes a solution to these problems. The basic strategy is an automatic feedback control for ventilation. We measure the pressure difference between the inside and outside of the house. The pressure inside the house decreases, when the exhaust fan works, then only the ventilation is not sufficient when the windows or ventilation holes are closed or the ventilation fan is at a standstill. Usually, we manually turn on the ventilation fan; thus, an ON-OFF ventilation control is sufficient. Two problems in creating a feedback system are pressure measurement and cost. In our application, a pressure on the order of several Pa with very low frequency must be measured, but there are no suitable low-cost and highly sensitive sensors.
1. INTRODUCTION The ventilation of houses is important to keep a house in good condition and maintain the health of its occupants. In most old houses, the air is ventilated by exhaust fans because there are so many no of aeration holes along through which external air penetrates. By contrast, newly built houses are airtight to keep out external noise and for energy efficiency. For reasonable ventilation, there should be a good balance between aeration and exhaust, but the most no of houses have active aeration fans or passive holes for exhausting air, which causes a new problem. Sometimes an exhaust fan is Š 2017, IRJET
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Here we present a simple feedback system that uses a ventilation fan as the actuator as well as a highly sensitive sensor for feedback. The ventilation fan cannot be used as the actuator and sensor simultaneously, so it is used in a time-sharing manner. This idea could be applied to any actuators that contain an internal feedback with reversibility characteristics. Motors with a coil and magnetic fields have internal feedback; they act as a motor when electric energy is supplied and as a generator when mechanical energy is supplied. Piezoelectric devices also have internal feedback. ISO 9001:2008 Certified Journal
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