Course:VANT151/2022/Capstone/APSC/Team2
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Project: Energy Recovery Dryer
Welcome to Team 2's VANT151 Engineering Design project page. This project's main objective is to design an energy-efficient dryer and ensure that it is mechanically complete and working flawlessly. Additionally, one of the focuses of this project is to create the dryer in the most ecologically responsible and sustainable manner possible. In order to successfully achieve the overall objectives of the project by meeting the specific goals required for each component, we were separated into the following sub-teams:
- Documentation Sub-Team
- Mechanical Sub-Team
- Electrical Sub-Team
- Structural Sub-Team
- User Interface Sub-Team
Project Overview
Problem Statement
Based on the experience and observations of users and manufacturers, it has been reported that conventional clothes dryers consume a large amount of energy and yet clothes do not dry completely.
To solve this problem, the concept of a "Energy Recovery Dryer" was proposed, with the idea of reusing the heat of the exhaust air produced by the dryer and allowing the clothing to be dried in less time while saving energy.
Overall Objectives
- Reaching the highest potential of energy recovery.
- Intuitive and functional user interface.
- Fully dried clothes.
- Fast drying.
Overall Functions
- Recycle the heat from exhaust air to increase the efficiency
- Not damaging the clothes.
- Accepting user inputs of temperature, time, motor speed and humidity
Overall Constraints
- Limited time for the project
- Limited equipment/components
- Restricted dimensions
- Having few people in the team
Gantt Chart
Mechanical Design
Mechanical sub-team is to design the mechanical parts of the clothes dryer. Also, mechanical sub-team is responsible for the CAD models of mechanical and Electrical/Electronic parts.
Requirements
The mechanical components must appropriately fit in the dryer and properly function.
Functions
- The clothes dryer transmits heat and airflow to keep the clothes dry uniformly at an efficient rate.
- Drying a cotton 15 x 15 cm handkerchief in less than an hour
- Transfer of heat flow through copper tubes
- Removal of moisture through air duct
- Condensing of steam with heat exchanger outlet
Objectives
- Designing a functioning drum drive which is the main component of the dryer for the dryer.
- 3D printing of the motor support
- Design a sensor support
- Bending the copper to create copper tubes (for an adequate airflow)
Constraints
- Restricted variety of equipment
- Limited time period or creating the dryer
- 0.5L minimum capacity of the drum drive
The Design
Drum Size
The volume of the drum is about 0.5L. The below diagram illustrates the basic design of the drum. The drum is made to dry smaller clothes. Furthermore it was calculated to operate at a desired speed. The most suitable drum design was that made of aluminium. The aluminum drum possesses properties such as good thermal conductivity, which can help heat transfer to clothes with ease. In addition, aluminum has a high melting point and strong intensity therefore preventing the drum from getting damaged. The final design is shown below.
Drive System and Motor Support
The motor will rotate the drum drive along with the helical gears that are attached to it. The motor mount will be placed beside the drum, on the bottom panel. A motor support is used to secure the motor while it is rotating the drum.
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Heat Exchanger Top
The heat exchanger top will be utilized to protect/secure the heat exchanger.
Electrical Design
Overview :The electrical sub-team is responsible for constructing the electrical circuit for this project and writing the necessary code to ensure that components such as the motor, fan, and heater function as intended.
Requirements
Functions
- A program capable considering user inputs for a drying cycle.
- Variable temperature controlled by user input.
- A sensor that regularly measures temperature and humidity to be used to then adjust the intensity of the heater.
- A motor with adjustable rotation speed.
- A fan that can be toggled on or off.
- A buzzer to notify the user of the start of the cycle, and its end.
- A limit switch, such that the drying cycle stops when the door is opened.
- Ensure the safety of the dryer to the user.
- Prevent any damage to the clothes.
Objectives
- Keep the energy consumption of the dryer below 45W
- Making the dryer run in a consistent and predictable manner.
- Rotating the motor at 10 rev/min.
- Using the available materials efficiently.
- Rising the temperature of the heater up to 80 C˚, and maintaining a high temperature for prolonged periods of time.
- Lower the response time of the limit switch to two seconds
Constraints
- Maximum power consumption of 24 VAC, 40 VA.
- Limited space do dry fit electronics 250 x 220 X 300 mm.
- Motor, heater, and fan were provided
Circuit Components
| Component | Specifics |
|---|---|
| Motor | Hobby Gearmotor Yellow 200 RPM |
| Fan | 9VDC |
| Sensor | DHT 22 |
| Heater | 24 VDC 20Ω |
Power Supply
The power supply converts 24V AC into 9V DC, as well as provide protection against surges in current through a multitude of capacitors. The 9V DC circuit is used to power the Arduino and the fan, and the 24V AC is used to power the heater. No alterations were made to the base design of the power supply.
Fan
The fan runs on a 9V circuit, which can be toggled on or off using the Arduino. The fan turns on when the drying cycle beings and off when it finishes.
Drum Motor
The motor is powered by 5V DC, and its rotational speed is adjustable via Arduino. The capacitors are necessary to protect the components from voltage fluctuations. The 10 uF capacitor prevents small voltage fluctuations, while the 0.1 uF capacitor, which is mounted on top of the motor, prevents large voltage fluctuations. The diode is used in the motor circuit to prevent current from flowing in the reverse direction and damaging the components. The MOSFET transistor in the motor circuit consists of three pins: gate, drain, and source. The MOSFET is controlled by the Arduino via the gate pin and is responsible for adjusting the motor's speed by applying different resistances in the circuit depending on the input voltage from the Arduino.
Alternative Design (Motor)
The motor could be designed with a constant speed in a given direction, adjustable speed in a single direction, or adjustable speed in both directions, In order to evaluate which option was the best for us, we conducted a weighed decision matrix, which can be seen below.
| Weight | Rotation in One Direction | Rotation and Adjustable Speed in Two Directions | Rotation and Adjustable Speed in One Direction | |
|---|---|---|---|---|
| Impact of the Quickness of the drying process | 40% | 33% | 33% | 33% |
| Ease of implementation | 15% | 50% | 15% | 35% |
| Impact on the efficiency of the dryer | 15% | 50% | 0% | 50% |
| User Friendliness | 30% | 20% | 40% | 40% |
| Total | 100% | 34.2% | 27.45% | 37.95% |
We decided to use single direction rotation with variable speed since there was no clear benefit of using it in two directions with variable speed, hence not making the additional work to incorporate that circuit justifiable.
Heater
The heater is the most complex electrical system of the dryer. It is powered by a 24V AC that powers the heater. The heater is triggered with a TRIAC, specifically the MOC3022M, once the Ardunio provided a voltage. Hence activating the heater. When the heater is activated, an LED turns on to indicate that circuit is live. No changes were made to the original heater design.
Temperature and Humidity Sensors
The temperature and humidity senors is a DHT22, which provides both the temperature and humidity of the ambient air. In the code, the temperature sensor is used to ensure that the temperature inside the dryer is equal to the user input, and that the humidity inside of the machine is not higher than what is desired. The program of the heater is dependent on the readings of this sensor. No changes were made to the provided circuitry of the sensor.
Extra Features
Limit switch
A limit switch is a simple switch mounted near the door that is used to determine whether or not the door is open. The limit switch has a logic pin and a positive pin; the logic pin is connected to input-declared pin 2 on the Arduino. The switch is released and the pin is set to zero when the door is opened. In the main code, the status of pin 2 is frequently checked using a "if" statement. When the door is opened and the pin is set to low, the "if" statement is evaluated as true, and a function is called within the "if" statement to turn off the heater and the motor.
Buzzer
A buzzer is an electrical component that can generate sounds of varying frequencies and duration. The buzzer has a logic pin and a ground pin, with the logic pin connected to the Arduino's output-declared pin 9. The buzzer is programmed to emit a simple melody to alert the user of the beginning and end of the drying cycle.
LED
The LEDs, similar to the buzzer, are there to give the user a clear indication of what the dryer is doing, these are connected to pin 8 and pin 5 respectively. When the dryer starts, the green and red LED alternate 3 times, when the cycle ends the red LED flashes three times and then both LEDs blink in together. When the door is open in a drying cycle the red LED flashed three times and then both blink together.
Alternative Design (LED)
Using 2 or 1 LED
Using one: no need to make an extra hole cut on the structure, no need to use a new Arduino since one of the pins in our Arduino was not working
Using two: having two different colors that can indicate whether the door is open or not, better visual presentation, need to make an extra hole on the top panel, having to use a new Arduino and check all its pins to make sure it was working.
| Weight | Single LED | Two LED | Two LEDS of different color | |
|---|---|---|---|---|
| Difficulty to implement | 30% | 40% | 35% | 25% |
| Difficulty to program | 30% | 30% | 30% | 40% |
| Ability to transmit information | 40% | 20% | 30% | 50% |
| Totals | 100% | 30% | 31.67% | 38.34% |
Given the results of the WDM, we diced to o for 2 LEDs of different colors in order to indicate different messages to the user.
Structural Design
Requirements
The requirement for the structural team are to work on the enclosure, openings/holes for the LCD and the buttons which are used as user interface, the door design and the tray which is used to collect water.
Functions
The function of the structural sub team is to make
- The outer enclosure of the dryer including the panels on the side
- The openings and holes for the LCD and the buttons for the LCD a 4cm by 8.5cm openings and holes of 1cm for the buttns
- The door design that is user friendly
- A tray that collects water with high efficiency.
Objectives
The objective for the structural team include making the:
- Frame of the dryer i.e., the enclosure made using aluminum, held together using different screws e.g., M5 and M4 to provide maximum safety.
- Holes on the top layer of the enclosure where the LCD and the buttons will be placed to make it easy to use.
- Door of the dryer should be user friendly and safe.
- Standard tray used to collect maximum water.
Constraints
The constraints for the project include:
- The size of the enclosure: as it is based upon the length of the aluminum components provided.
- The dryer needs to have openings in the top for the LCD and the buttons.
- The size of the openings is also a constraint as it should be equal to the diameter of the buttons and the LCD.
- The size of the EneRec Dryer cannot not exceed 250 x 220 x 300 mm.
The Design
Door
The design we choose for the door is a rectangular door which is closes using a magnet connected to spring. We choose this design after
comparing it with the alternate design that we made. the other design would have been worse than this as it did not have anything to keep
the door closed and also the design we made enables use of maximum space. The iris door design was not choose based on the fact that
it is not safe to use. The alternate door designs were rejected based on the Weightage determining matrix.
| Design Criteria | Weightage | Iris door design | Circular door design | Rectangular door design |
|---|---|---|---|---|
| User friendly | 50% | 20% | 40% | 40% |
| Effectivenees | 30% | 43% | 15% | 42% |
| Difficulty to implement design | 20% | 50% | 25% | 25% |
| Average weight | 100% | 37.67% | 26.67% | 35.67% |
Enclosure
The enclosure of the dryer consists of an rectangular structure made using aluminum components. The enclosure is made using four 18cm, four 26cm and four 25cm aluminum rods. The 18cm and 26cm rods are used make the top and bottom panel of the structure and the four 25cm aluminum rods are used to hold these two panels together. This structure is used as it allows for maximum soace to put the inner components of the dryer. A visual representation of the structure is shown. Moreover, the enclosure consists of the side panel and the top panel with designs shown in the images below.
Openings / Holes
The openings for the LCD were based on the needs of the users and which placement would be more convenient for the users. That is why we made the openings on the top panel which makes it easier for the user and the arrangement of the buttons was also decided based on that fact.
Tray
For the tray, we used the standard design that is used to collect the water. We decided to place it at the bottom of the dryer to increase efficiency. The shape of the tray was decided to be a bit circular to have maximum surface area to increase water collection.
User-Interface
Overview of the user-interface sub-system
Requirements
The user interface is responsible for soldering the buttons, compiling code that reads the input from the buttons, displaying the function on the LCD screen and starting the drying procedure.
Functions
The user interface sub-team was responsible for the following operating functions:
- Automatic drying
- Customizable time, temperature, speed and humid
- Emergency stop whenever needed or the door is open
- Stop at any moment during the operation
Objectives
The objectives of the user interface sub-team comprised:
- Ease of use
- Customizable manual
- Buzzer ring when done drying
- The drying machine should be able to repeat the code sequence without unplugging the power source
- The code has to be fully debug operate with minimized delay
Constraints
The constraints for the UI included:
- An LCD that only shows 4 rows and 20 columns
- Maximum of 5 buttons
- One button to start the default drying
- Time limitation of 60 mins
- Limit customizable time, temperature, speed and humid
- Limited space to guide the user on the LCD screen
- Automatic operation mode and Manual operating system, which includes customizable time, temperature and dryness.
The Design
Hardware Layout
a. Buttons layout
Some of the ideas withdrawn in brainstorming buttons layout
- Idea 1 includes a four-button operation that is responsible for up and down operations with one confirmed at the bottom and the back button on top.
- Idea 2 includes four buttons: up, down, back and confirm button with back at the bottom and the confirm on top.
- Idea 3 shows four-buttons operations with up and down buttons with confirming and back on two sides of the down button.
- Idea 4 presents four buttons operation with confirming and back in the middle.
- Idea 5 shows two-button operations with up and down buttons which also function as confirm and back when held for a period
- Idea 6 presents horizontal operations with left, right, confirm and back buttons.
Figure 1 shows the brainstormed ideas.
From the ideas brainstormed and a group discussion, the final button layout decision was idea number 6.
The decision was made based on:
- User-friendly (minimized the cursor movement)
- Minimal number of buttons pressed to get to the user's choice
- The adaptation to the LCD screen limitation (4 x 20, the options are horizontally organized)
- The ability to appear all the choice.
Idea number 6 has four buttons the top two responsible for left and right movement of the cursor on the LCD screen, and the bottom two responsible for back and forward from the options shown on the LCD screen.
| Layout 1 | Layout 2 | Layout 3 | Layout 4 | Layout 5 | Layout 6 | |
|---|---|---|---|---|---|---|
| Simple layout | 2 | 2 | 1 | 1 | 3 | 2 |
| The least space cover | 2 | 2 | 1 | 1 | 3 | 2 |
| The least number of buttons | 2 | 2 | 2 | 2 | 1 | 2 |
| Horizontal operation | 1 | 2 | 1 | 1 | 1 | 3 |
| Total score | 7 | 8 | 5 | 5 | 8 | 9 |
Operating Sequence
Some of the brainstorm ideas of the LCD options layout
Figure 2 shows the sequence of LCD pages whenever user input a button. The precision of user choice of value at the decimal place and can add up to infinite.
Figure 3 shows an improvement of the LCD sequence idea 1 with user-friendly information like 30% and 50% rather than specific speed and separation of increase and decrease adjustment.
Figure 4 represents a horizontal arrangement of buttons with box contains X as a customizable value.
The final LCD operation was decided to be idea 3 or draft 3 of the LCD sequence.
The decision was based on the following criteria:
| Sequence 1 | Sequence 2 | Sequence 3 | |
|---|---|---|---|
| User friendly (Simple LCD layout) | 1 | 1 | 2 |
| Precise customizable options | 2 | 3 | 1 |
| Require Vertical Scrolling | 1 | 1 | 3 |
| Less button press required | 1 | 1 | 3 |
| Total score | 5 | 6 | 9 |
Figure 6 shows the final Introduction or Menu page on the LCD screen.
Figure 7 presents the final manual page on the LCD screen.
Figure 9 shows the drying completion after the drying process have completed.
The final version of the welcome page was evaluated based on the following criteria:
- A concise and clear guide for the user (User friendly)
- Has appropriate arrangements of letters and cursor
The Arduino code for operating the buttons input. Here is the sample of buttons interaction with the serial monitor.
Sandbox:Arduino code for buttons
The Arduino code for operating the LCD screen appearance. Here is the sample of buttons interaction with the LCD screen.
Sandbox:Arduino code for LCD screen
The Arduino code for every page appear in the LCD screen
The Arduino code for UI sub team
Sandbox:Arduino Code for UI subteam
The complete version of Arduino code
Sandbox:Complete version of Enerec Drying machine
Program Flowchart
The final flowchart was made base on the LCD sequence 3.
The sequence starts to operate when the source power is live Introduction page shows up after 2 seconds of waiting for the buttons' input. After the user decision on Auto or Manual, the LCD screen is going to present and direct to the summary if the user choice is auto with a default value if the user's choice is manual, the LCD is going to redirect and present customizable manual by left and right buttons to move to different options and Ok or Back buttons to increase or decrease the value. The LCD will change consistently when the user picks an option, increases or decreases a value and confirms or back when they satisfy with the value chosen. The drying machine begins to run when the summary page of the user option is shown. While the drying operation, whenever the door is open, the drying will stop within 3 seconds and the error page is shown.
Recommendations
The code provided above is not fully optimized due to the limited timeline to complete the project. An improved version could put the user choice of value in an array, by indicating each position as temperature, humidity, time and speed. Using an array function will much simplify the length of code. Defining all the components as a pin value at the start will save plenty of time if the other sub-team needs to change the pin. Compressing each action into a function is easier to work with as the function can be recalled at any point. A serial monitor is highly recommended to use as a tracker in any function while debugging the code. Furthermore, the serial monitor can print the value measured by the sensor to the LCD screen for the team to overlook while testing.
Conclusion
Appendices
Assembly Drawings
References
Virtual & Actual Prototype Demo
About Us
| Documentation | User Interface | ||
|---|---|---|---|
| Hello everyone, I am Elif. I am the single member of the documentation sub-team. Since the first day we began the project, I have tried my best to support the team in any way I can, in addition to updating our team's Gantt chart, improving communication between subteams, outlining the project, and creating the assembly drawings and this wiki page. Though there were instances when the process was really challenging, there was not much time, I believe we were still able to collaborate. I gained a lot of new knowledge during this experience, particularly noticing the responsibilities of being a team. The most astonishing thing I've learned so far in this project's scope is that a product's sustainability can be determined using Solidworks, depending on the location and material where the pieces are manufactured and used. I have gained quite a bit of new skills and I am grateful for this opportunity. I want to sincerely appreciate my project team members for their tireless efforts and commitment to providing the finest work possible! | Hello everyone, I am Duc Thang Huynh, also known as Dustin. I am the only member of the user interface (UI) sub-team. The user interface sub-team is an independent sub-team with minor communication needed. Time and flexibility in terms of affecting the team aren’t a challenge for the UI sub-team. Since I have done the final version code early, I have a chance to hop on to other sub-teams to cooperate like the structure, electrical and mechanical sub-team. I have gained plenty of experience from debugging and tips to track the bugging loop or errors by using a serial monitor. The valuable takeaway is the importance of a solid deadline and getting ahead of the work, which keeps everyone to stay working on the project. The teamwork pace is an interesting perspective since each sub-team has different tasks to do, not moving on to the next task might not mean the lateness on the team project timeline due to the level of attention and detail on the task required. After all, I appreciate the effort and work that each team member takes part in the project with limited members and timelines. | ||
| Mechanical | |||
| Hello everyone my name is Jerry Yang, a mechanical sub-team member and the leader of team 2. As a group leader, I held a meeting on a weekly basis so that the group members and myself were on the same page. In terms of the mechanical sub-team itself, I contributed to the project by consulting the front ring and drum drive with my fellow colleague Chidera. On top of that, we came up with the helical gear design together. Marcelo assisted with the motor mount while I was completing the design for the sensor mount as well. One of the challenges that we faced as a group was the lack of members, leading to more work for the individuals. However, props to my cooperative and supportive teammates, we were able to successfully complete our Enerec Dryer. I am grateful for the opportunity to work as a team leader as well as getting to work with diligent members. Besides that, working in the mechanical sub-team really intrigued me to the field of mechanics. | My name is Chidera Chima. I am in the Mechanical Sub-Team. Some of my contribution to the team includes creating the heat exchanger top, as well as the helical gears. I faced some challenges concerning the motor mount creation but with the help of my team members, I was able to 3D print the motor mount. I enjoy working with the team because even though challenges occur, it is easier when we work together. I hope the outcome of this project is successful, and I hope to work with this group in the future. | ||
| Electrical | |||
| I am Ashkan Ahmady Afkham, an electrical sub-team member. I thoroughly enjoyed participating in this project, particularly in the electrical sub-team, which includes both hardware and software, which are my two primary areas of interest. One of the greatest obstacles we faced was the limited time we had to complete the project, given that our group consisted of only 8 people. Another challenge we faced was developing and implementing extra features. This was difficult due to the limited space we had on the breadboard to fit all the circuits, and because all our extra features (limit switch, buzzer, and LED) required collaboration with structural sub-team to mount the components on the main structure. However, we were able to successfully complete the project with three extra features. I would say that our success was primarily due to hard work, effective communication, and time management. Despite all the obstacles in this project, I learned a great deal about applying knowledge in the real world, working in a team, and developing multiple approaches to a problem. This also assisted me in identifying my technical and non-technical weaknesses and working to improve them for future projects. At the end, I would like to truly thank all my team members for their hard work and commitment to this project. | Hello everybody, my name is Marcelo. I am one of the members of the electrical team. Before this project, I had minimal experience with dealing with electronics and constructing electrical circuits. Additionally, because of our relatively low number of team members, I also had a hand in different s-b teams, helping to assemblvariousnt components. Thano our all our collaborative efforts, we wery able to complete this project. This project has taught me a great deal if electronics and other disciplines, which I intend to carry with me into future projects. I sincerely appreciate the effort and dedication given by all of our, teammates and I hope that we get to work together in the future! | ||
| Structural | |||
| Hello, I'm Haonan Zhou. I am a member of the structure sub-team. In this project, I designed the door design, the door opening design, drew the design layout on paper, and helped the team members assemble the equipment. Although in some cases our communication had problems, and another team member sometimes liked to deal with some problems alone, it was difficult for me to step in and help him, but after later communication, we could cooperate better and more harmoniously. In this experience, I learned a lot of new knowledge. In particular, I noticed that I often communicate with the team. Ensuring good communication is the most important part of team cooperation. So far, the most amazing thing I have learned in the scope of this project is the high use of 3D modeling software in the whole project and the perfect cooperation with 3D printing. I have acquired quite a number of new skills and I am grateful for this opportunity. I would like to sincerely thank my project team members for their unremitting efforts and commitment to provide the best possible work! | Hello everyone, I am Jibran Khan. I am one of the members of the structural sub-team. Before this project I had no knowledge about 3-D modeling and the steps engineers take to design components. For the project, I designed the panels which include the side panels, the top panel, and the front panel. Additionally, the holes for the bottom and back aluminum sheet were also done by me. The assembly was mostly done by the structural sub-team with help from the other teams. Through this project, I learned how to properly communicate between different sub-teams and how to design components using solid works and to decide on the final design by making multiple alternate designs and evaluating them; these skills will be very helpful in future years. Overall, through everyone’s effort we were quite successful in this project and I am very thankful that everyone took this project seriously. | ||
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