course project presentation
DESCRIPTION
Course project presentation. Thursday in class Timing: 4 minutes (strictly controlled) Approximately 1 PowerPoint Slides per minute Content Problem Introduction Methodology Results Comments and recommendation You need to email me your presentation before the class! - PowerPoint PPT PresentationTRANSCRIPT
Course project presentation
• Thursday in class
• Timing: 4 minutes (strictly controlled)• Approximately 1 PowerPoint Slides per minute
Content • Problem Introduction • Methodology • Results • Comments and recommendation
• You need to email me your presentation before the class!
• 2 minutes for Question and Answers
Final project report
• Introduction
• Methodology
• Results
• Comments
• DO NOT submit pictures without comments
• Analyze the result - create diagrams and tables
Objectives
• Finish control systems – sequence of operation • Psychrometric chart
• Learn about desiccant systems • Psychrometric chart
• Learn about software for load calculation
• Review
HVAC ControlExample 2:
Dew point control (Relative Humidity control)filter
fancooling
coil
heating
coil
filter
mixing
damper fresh
air
T & RH sensors
We either measure Dew Point directly or T & RH sensors substitute dew point sensor
Humidity generationHeat gains
We should supply air with lower humidity ratio (w) and lower temperature
Relative humidity control by cooling coil
»TDP
Mixture
Cooling Coil
RoomSupply
»Heating coil
Relative humidity control by cooling coil (CC)• Cooling coil is controlled by TDP set-point
if TDP measured > TDP set-point → send the signal to open more the CC valve
if TDP measured < TDP set-point → send the signal to close more the CC valve
cooling
coil
heating
coil
»mixing
Fresh air
Tair & TDP sensors
Control valves
• Heating coil is controlled by Tair set-point
if Tair < Tair set-point → send the signal to open more the heating coil valve if Tair > Tair set-point → send the signal to close more the heating coil valve
Sequence of operation(ECJ research facility)
»Control logic:
»Mixture in zone 1: IF (( TM<TSP) & (DPTM<DPTSP) ) heating and humidifying
»Heater control: IF (TSP>TSA) increase heating or IF (TSP<TSA) decrease heating
»Humidifier: IF (DPTSP>DPTSA) increase humidifying or IF (DPTSP<DPTSA) decrease humid.
»Mixture in zone 2: IF ((TM>TSP) & (DPTM<DPTSP) ) cooling and humidifying
»Cool. coil cont.: IF (TSP<TSA) increase cooling or IF (TSP>TSA) decrease cooling
»Humidifier: IF (DPTSP>DPTSA) increase humidifying or IF (DPTSP<DPTSA) decrease hum.
»Mixture in zone 3: IF ((DPTM>DPTSP) ) cooling/dehumidifying and reheatin
»Cool. coil cont.: IF (DPTSP>DPTSA) increase cooling or IF (DPTSP<DPTSA) decrease cooling
»Heater control: IF (TSP>TSA) increase heating or IF (TSP<TSA) decrease heating
Set Point (SP)
Mixture 2
Mixture 3
Mixture 1
»DBTSP
DPTSP
Sensible and Enthalpy and Desiccant wheels
Desiccant wheel
»Figure 3 – A desiccant-based cooling system combined with regenerative heat exchanger, vapor compression cooling, and evaporative
humidifier (hybrid system).
Computer software for load calculation
• http://www.xpedio.carrier.com/idc/groups/public/documents/marketing/hap_ehelp_009.pdf
• http://www.doe2.com/equest/
• http://tc47.ashraetcs.org/pdf/Presentations/Liesen_Chicago.pdf
Residential vs. Commercial systems
• Course focus was on HVAC equipment that is used in both: residential and commercial systems
• Emphasize on the application in commercial systems
Commercial HVAC Systems
Single zone Multi zone
VAVCAV VAV CAVAll Hydroinicthat relay on infiltration
With and without reheaters
DOAS with fan coilsor radiant ceilings
With reheaters
Dual duct
Dual duct DOAS with
fan coils
With and without humiditycontrol
This is not the complete list !
Typical Components in Commercial systems
• Constant operation
• Outdoor air supply
• Two fans (supply and return)
• Multizone system
• Control
• …..
Residential System
Course objectives• Apply fundamental physical principles to HVAC
design• Describe and size each component in an HVAC
system• Design HVAC systems based on manufacturer’s
datasheets• Contrast residential systems with commercial
systems and use appropriate design techniques for each type of system
• Solve HVAC design problems with high-quality references