HRS: Heat Reclamation System Aleksey Treskov Evan Lamson Sarita Gautam Wyatt Mohrman Tegan Argo Eamon Mcmillan Faisal Albirdisi

Mission Statement The objective of our project is to transfer the heat energy created by the internal resistance of computer components into a state where the energy can be recollected in the form of electricity. In addition, we will be able to increase the processing power of the computer. Tegan Faisal Eamon Wyatt Aleksey Evan Sarita

Vision Efficiently dissipate heat from the computer Capture energy that is lost by the computer Charge an electronic device using reclaimed energy Manipulate computer clock speed Monitor the system functionality using an Android device Tegan Faisal Eamon Wyatt Aleksey Evan Sarita

Goals Low Level –Basic Heat Transfer Pipeline –Constructing the Case Mid Level –Display monitoring system temperatures, clock rates, and power generation –Control system to maintain best possible temperature difference –Maximize power generated High Level –Fully automated control of clock speed, flow rates, and power generation. Tegan Faisal Eamon Wyatt Aleksey Evan Sarita

Background Computer cooling is required to remove waste heat from computer components to keep them within permissible temperature limits. Traditional Method –Combination of heatsinks and fans Fans are used to cool the heatsinks that take heat away from computer components Liquid Cooling Method –Water Cooling System Circulates water through a cooler to absorb heat from the CPU and then to a radiator to be cooled back down –Submerge in Oil Completely submerge the computers components in a non-conducting liquid to absorb the heat Tegan Faisal Eamon Wyatt Aleksey Evan Sarita

Why Mineral Oil ? Non-conductive. Specific heat of 1.67 kj/kg°k (1.012 for air) Thermal conductivity of.133 w/m°k ( for air). Easily accessible. Several industrial applications. Tegan Faisal Eamon Wyatt Aleksey Evan Sarita

Why Thermoelectric Generators? Industry already uses it in waste heat recovery applications They’ve been around for a while ( not a new technology). Easy to implement ( You only need a temperature differential). A way of harnessing thermal energy w/o building a steam engine. Tegan Faisal Eamon Wyatt Aleksey Evan Sarita

How?

System Block Diagram Control System Desktop PC Computer User Power Data Visualization DC Power TEG Power Reclamation Display

Control System Level 2 Functional Decomposition Pump Control Computer Control µController Bluetooth module Clock Speeds Thermal Sensors Flow Rate Sensor User data

Control System Input Thermal sensors –Heat Differential Two Diodes to monitor Hot and Cold side Temperatures –Operating Maximum Hot side diode and computer built in temperature sensors Flow Rate Sensors –Flow Rate –Pump Speed Voltage Clock Speeds –Current processes Clock Rate –Fan Operating Speed User Data –Serial input from paired Bluetooth device State Change Pump Control Computer Control µController Bluetooth module Clock Speeds Thermal Sensors Flow Rate Sensor User data Tegan Faisal Eamon Wyatt Aleksey Evan Sarita

Control System Output Pump Control Asserts a 0-3.3v PWM signal to vary pump rate Computer Control Outputs serial communication to interact with computer Outputs Control Signal to change Clock Speed Outputs Power On / Off Signal Data Output Temperature readings Successful state changes Current Operating mode Pump Control Computer Control µController Bluetooth module Clock Speeds Thermal Sensors Flow Rate Sensor User data Tegan Faisal Eamon Wyatt Aleksey Evan Sarita

Control System Implementation To handle the various I/O communication present in our project we have selected to use a µController in conjunction with Bluetooth Module. µController Arm Cortex Microcontroller Capable of capturing and asserting all control related signals Low Power Operation (Suspended operation) Familiarity Bluetooth Module Blue Tooth Radio (RN-BlueSMiRF) Android Compatible Low Cost Tegan Faisal Eamon Wyatt Aleksey Evan Sarita

Control System High Risk Components The Largest Problem associated with our Control system is timing. We are required to capture several input output signals, change states accordingly, while outputting display data. To solve this problem a second microcontroller may be added to allow parallel polling of various sensors. Tegan Faisal Eamon Wyatt Aleksey Evan Sarita

Thermoelectric Generators Heat is carried by holes in P type, electrons in N type. Across each junction a small voltage is produced. Place many of these in series to get useful voltage. Heat -> DC Volts Tegan Faisal Eamon Wyatt Aleksey Evan Sarita

TEG resistance varies with temperature Typically between 1.8 to 3.3 ohms per TEG module. Problem with using semiconductors is the internal resistance. Tegan Faisal Eamon Wyatt Aleksey Evan Sarita

Maximum power transfer theorem In order to get the most power from the TEGs we must match the load resistance to the TEG internal resistance. Tegan Faisal Eamon Wyatt Aleksey Evan Sarita

Basic Energy Harvesting MPP MPP converter matches our load impedance (battery for example) to TEG internal resistance over different temperature ranges. Tegan Faisal Eamon Wyatt Aleksey Evan Sarita

Duty cycle controlled MPP The load voltage (and resistance) is transformed with the MPPT according to the duty cycle. When a duty cycle is chosen such that the load resistance equals the TEGs internal resistance, maximum power is transferred. Tegan Faisal Eamon Wyatt Aleksey Evan Sarita

Study Results** **Development of a thermoelectric battery- charger with microcontroller- based maximum power point tracking technique *Jensak Eakburanawat *Itsda Boonyaroonate MPP tracking improves TEG power generation by more than 15% over direct charge. Tegan Faisal Eamon Wyatt Aleksey Evan Sarita

Display Android interface 4.0 –Previous experience –Open Source –GraphView library External monitor –MatLab Display –Temperature data –Power reclamation data –Clock speed of the computer Tegan Faisal Eamon Wyatt Aleksey Evan Sarita

Bluetooth Radio (RN-BlueSMiRF) 45x16.6x3.9mm Hardy frequency hopping scheme - operates in harsh RF environments like Wi-Fi, g, and Zigbee Operating Temperature: -40 ~ +70C Operating Voltage: 3.3V-6V Transmitting distance 18 meters Tegan Faisal Eamon Wyatt Aleksey Evan Sarita

Testing Two identical systems in two different environments. Compare processing powers with operating temperature. Compare overall energy savings Tegan Faisal Eamon Wyatt Aleksey Evan Sarita

Overview System Roles and Responsibilities ResponsibilitiesRolesHW/SW Check CPU tempsSystem Check Module (SCM)HW : On-board temp. sensors SW : Send data to CSA/FRA Check fluid tempsSystem Check Module (SCM)HW : Digital therm. Sensors SW : Send data to CSA/FRA Increase/Decrease ClockClock Speed Adjustor (CSA)SW : Compare temps to optimal settings, send command to overclocking program (PC) Pump fluidsFlow Rate Adjustor (FRA)HW : Micro-pumps SW : Compare temps to optimal setting, send pwm signal to pumps Switch ModesMode SelectHW : Touchscreen interface SW : Run benchmark utility depending on which mode user has selected. Display DataGrapherHW : Android device / LCD display SW : Collect temperatures, clock speed, and pump speed data; display current readings and real-time historical graphs Maintain SafetySafety ModuleHW : Servo-controlled case vents, pressure release valve, GFI SW : Compare temperatures with maximum levels; increase flows, decrease clock, and/or open vents as needed Harvest EnergyTEG Array ModuleHW : TEG's, power converter, battery Track MPPMPP TrackerHW : Interface with power converter SW : Detect and operate at MPP duty cycle Send/Receive DataCommunications ModuleHW : RN-42 Bluetooth SW : Encode data for transmission to Android App

Overview System Diagram

Overview System Diagram: Display

Overview System Diagram: Control

Overview System Diagram: Power Circuit

Constraints/Limitations Max operating temp: ~90°C Max TEG efficiency: ~10%. Maximum Clock Rate Tegan Faisal Eamon Wyatt Aleksey Evan Sarita

Risks and contingency plan

Risks Overheating of components Inadequate temperature differential Occurrence of ground fault Timing Constraints Tegan Faisal Eamon Wyatt Aleksey Evan Sarita

Contingency Plan In case of overheating: Decrease the clock speed. Increase the flow rate of cold oil. In case of inadequate temperature differential: Increase the clock speed (Hotter hot side). Increase the cold water flow rate ( Colder cold side) Risk of ground fault: Plug the equipment into a GFCI (Ground fault circuit interrupter) protected outlet. For timing constraint: Additional processing by adding a second microcontroller. Tegan Faisal Eamon Wyatt Aleksey Evan Sarita

Schedule: Fall Semester

Schedule: Spring Semester

Budget

Division of Labor

Questions

Extra Slides Here Be A 3 Headed Dog!!!

Constraints/Limitations Max operating temp: 100°C Max TEG efficiency: 10%.

Energy Harvesting ΔT ≈ 70°C V = [volts]I = [amps] MPP tracking. Cascaded Buck-Boost Converters V_ο = [volts] I_ο= [amps]

Safety Pressure control Valve Emergency Shut off Automatically activated vents

Control System

Thermoelectric Generators TEG’s –Efficiency 5-10% –Simple to implement Seebeck effect Peltier effect Thomson effects Uses –Cars –Solar Cells –Spacecrafts

Micro Hydro Pump