PERFORMANCE IMPROVEMENT OF AHU IN THE HVAC SYSTEM USING PID CONTROLLER

Project Abstract / Summary : An air handler or air handling unit (AHU), is a device used to regulate and circulate air as part of a heating, ventilating, and air-conditioning (HVAC) system. It is a prominent system because of its relationship with energy savings and environmental, economical, and technological issues. Electric Motors have a large share of the daily energy consumption. However, around 25% of the world's electrical energy is consumed by electric motors in industrial applications, which are especially conducive for energy savings using VFDs in centrifugal load service. Most motors (blower) in the commercial sector are used to Air Handling Unit (AHU) in the Heating, Ventilation and Air Conditioning (HVAC) systems.

In this project we take up one such segment of the air handling unit which is the blower. In the existing system, the blower is controlled by means of variable-frequency drive (VFD) by varying blower input frequency and voltage. But, the frequency is preset to constant value by manual adjustment. Also, failed to respond instantly due to the sudden increase/decrease in thermal load and at no thermal load condition.

In this project we propose a proportional integral derivative (PID) controller, control loop feedback mechanism to control the blower speed automatically. The closed loop system is provided in which the return air temperature is measured by means of the temperature sensor and interfaced with the proportional integral derivative (PID) controller. Then, the desired frequency and voltage changes correspondingly to blower by means of variable-frequency drive (VFD) which is interfaced with the PID and the blower speed changes correspondingly with respect to the thermal load. As the result, cool or hot air flow rate and specific humidity changes due to increase or decrease of the thermal load. Finally, this PID controller aided AHU provides automatic control of blower (fan) speed which results in high comfort with increased AHU life and an efficient energy conservation system in total HVAC system.

Why did you choose to work on this project topic : Electric Motors have a large share of the daily energy consumption.Around 25% of the world electrical energy is consumed by electric motors in industrial applications, which are especially conducive for energy savings using VFDs in centrifugal load service.

Project Highlights : OURS PROJECT COMES UNDER ON ENERGY CONSERVATION THEMES WHICH IS PREDOMINANT CRITERIA FOR THE CURRENT ERA. BASED ON OUR PROPOSAL THEIR WILL BE A HUGE IMPACT ON THE ENERGY CONSERVATION SYSTEM AND AUTOMATION PROCESS. IF OUR PROJECT IS ENROLLED AS THE BEST ACADEMIC PROJECT, THEN IT WILL BRING US A GREAT RECOGNITION TO OUR PUBLISHMENT AND I BELIEVE THAT WE DESERVE TO WIN THE CONTEXT.


Project Category : Mechanical / Automobile / Aeronautical
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Institute/College Name: SRI SAIRAM INSTITUTE OF TECHNOLOGY
City: CHENNAI
State: TAMILNADU
Participating Team From: Final Year