We dedicate the above project to our beloved parents without whom this would have been a utopian plan. Needless to say, we are grateful to Almighty Allah for giving us the strength and efforts to realize this huge project in a limited time. First of all, we would like to thank and salute “Almighty ALLAH”, the most merciful, the most gracious, the source of knowledge and wisdom bestowed upon Almighty humanity for the successful completion of this study.
Department of Mechanical Engineering, Sonargaon University (SU), for his kind constant guidance, close encouragement, advice and valuable time spent on the numerous discussions we had on our thesis. Mostofa Hossain, head of the Department of Mechanical Engineering and all respect teachers from the Mechanical Engineering Department for their cooperation and considerable help in completing the thesis work successfully. We are also thankful to our classmates for their support and also those who helped us to make this project successful.
Finally, we express our sincere gratitude to our parents and relatives for their moral support. The air handling unit (AHU) is one of the most important devices in HVAC (heating, ventilation and air conditioning) systems, especially in large-scale buildings, providing both heating and cooling for multiple zones. Furthermore, hybrid systems for the integration of rotary adsorption dryers with the AHU unit and the primary treatment unit are being investigated.
To illustrate the design of the AHU system, a case study on cold vaulting is presented.
INTRODUCTION 1.1 Background
Classification
During the economizer cycle, the return air and outside air dampers are modulated to seek the mix air temperature at the design supply air temperature set point. In theory, the outside air temperature range for economizer cycles can be extended to the same temperature as the return air temperature. The supply air temperature can always be maintained at the designed set point by modulating the outdoor air flow with outdoor and return air dampers.
On the other hand, the mixed air temperature is always higher than 12 °C even if the outside air damper is fully opened when the outside air temperature is higher than 12 °C. The mechanical cooling is normally required to maintain the supply air temperature set point. The supply air temperature must be set at 12 °C if the outdoor air is humid or in other words the outdoor dew point is higher than 12C.
However, the supply air temperature is not limited to 12°C if the outside air is dry and the space has a partial cooling load due to heat transfer from the envelope and the occupants' schedule. In this case, the AHUs can still maintain the room temperature with a variable supply air temperature instead of the design value.
Research objectives
Research methods
For the best quality of life, the air we breathe must be the purest possible, because air nourishes the lungs, the blood and consequently the rest of the organs with oxygen.
CHAPTER-2 PROJECT ANALYSIS
Definition of term
Equipment
- Selector switch
- RH Heater
- COOLING FAN
- Fan Motor
- Relay
- Red Indicator
- Green Indicator
- Two Pin plug
- Wire
- Block diagram
In addition, the methods' scalability to a large number of different air handling units is evaluated in the interest of commercial feasibility. The higher the relative humidity, the harder it is to evaporate water from the filter, which is why a humidifier is self-regulating -- as the humidity increases, the humidifier's water vapor output naturally decreases. As the electric current reaches the motor, it enters coils of wire wound around a metal base.
When this current passes through the wire, it creates a magnetic field which further exerts force in a clockwise motion.12V Max. 2-pin plugs consist of two flat or round pins with one called "hot" or "live" and the other called the "neutral". When connected to an electrical circuit, current flows from the live pins through the copper conductor and into the device.
Electrical cables consist of a core of metal wire that provides good conductivity, such as copper or aluminum, along with other material layers, including insulation, straps, shields, armor for mechanical protection, and sheathing.
MODERN AIR HANDLING UNIT
- Required Equipment
- Working Principal
- Working Procedure
- Chill Water Line
- Hot Water Line
- Chambers of an AHU
- G grade filter
- F grade filter
- H grade filter
- Dehumidifier
- Bed Filter
- Duct and Ventilation system
- Ventilation System
- Chilled water Hot water system
- Chilled water
- Hot water
- Sensors
- Description of the HVAC system
- Data acquisition and processing
- Performance analyses
Then check that the signal connection of the automatic pneumatic valve in the return line is correct. At the heart of the water-cooled system, a chiller removes heat from water through a refrigeration cycle. A chilled water system's cooling cycle works by removing heat from chilled water in the evaporator of the chiller.
In the condenser of the refrigerant, heat is transferred to the condenser water, or directly to the outside air. And the supply and return line connected to the AHU. the manual valve should be kept open, also check that the signal connection of the automatic pneumatic valve of the supply line is correct. The heater connected to the dehumidifier (if an electric heater is used) has an open damper in the air intake and outlet line, and the most important thing is to check that the dehumidifier's impeller bed (moisture suction) is dry.
The hot water supply pipe is connected to the lower end of the AHU heating coil, and the entire coil turns around and exits through the other end to return to hot water production. And when it is reheated, the hot water is returned to the AHU heating line and thus circulates. Depending on the appropriate humidity (RH) or air temperature, the automatic hot water supply valve closes or opens.
Not all sensors are used in all AHUs and the use will depend on the control strategy and goals of the ventilation system. A schematic of the HVAC system is shown in the figure, with its main components and instruments available. The data acquisition software in the first part of the project was a custom SCADA application written in Movicon (similar to VBasic) and the data was sent via MODBUS/TCP.
In the first implementation of the project, data storage was one data point every 15 minutes, which was a poor solution from a statistical point of view. The main reason was the unreliability of the data acquisition process, which took place on a physical computer and was subject to multiple failures. Instead, comparing the available daily values can provide useful insights into the behavior of the system and its changes on a daily and seasonal basis.
The main purpose of the performance analysis is an assessment of the AHU operation over time. Several activities have been carried out on the available data and some of the results are presented in this paper.
RESULTS AND DISCUSSION
Results Discuss
AHU-2A-01 after 10 minutes of running, we find that the temperature value of the parameter has moved closer to the value of the set point, but the value of the parameter of Relative Humidity (RH) cannot move. We start the dehumidifier and see that the relative humidity (RH) value of the parameter has moved closer to the set point value, and after running the dehumidifier for 20 minutes, we see that the value of the parameter matches the value of the set point.
Components price list
Air Handling Unit Modify
If the system has more than one AHU, I will install an FCU (fan coil unit) to supply fresh air to everything, which will reduce the cost of maintaining many filters. We will divide the dehumidifier heater into 4 steps: - low temperature, very low temperature, high temperature, very high temperature. The stated objective of the thesis was to evaluate and identify methods for the maintenance of air conditioners according to the condition that can be implemented with the data available today, on the other hand, to identify the possibilities that arise from further data collection.
The research focused on fault detection and diagnosis methods integrated in supporting maintenance decision-making. After the literature review, it can be concluded that condition-based maintenance in building systems must overcome the challenge of suboptimal condition monitoring. In industrial contexts, the consequences of failure are generally more extensive in terms of cost and safety, and as such there is a greater incentive to invest in sensors and other infrastructure necessary for condition monitoring.
While anecdotal evidence suggests that e.g. smarter actuators with self-diagnosis capabilities are becoming slightly more common in new build building systems; the data is generally not transmitted out of the devices and is therefore not available for any centralized analysis. In addition, information about occurred faults and other events, such as maintenance activities or parameter changes, appears to be largely unrecorded, further complicating attempts to automate anomaly detection.
