Thermodynamic Simulation of a Detached House with District Heating Subcentral

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Thermodynamic Simulation of a Detached House with
District Heating Subcentral

• Jonas Gustafsson, Jerker Delsing Jan van
  Deventer
• Division of EISLAB
• Dept. of Computer Science Electrical
  Engineering
• Luleå University of Technology
• E-mail j.gustafsson_at_ltu.se

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Luleå University of Technology

• 65 37 North
• Further north than Anchorage, Alaska
• People
• 12000 students
• 1600 staff

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Outline

• About district heating
• Model description
• Validation
• Conclusion and future work
• Questions

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District heating
District heating is a system for distributing
heat generated in a centralized location for
residential and commercial heating requirements
such as space heating and water heating

• Central plant instead of a boiler/heater in every
  house
• Heat is transported from the heat plant in pipe
  networks
• Substation transfers heat to house internal
  radiator and tap water systems
• Important to have good efficiency in the
  substation
• Cold water back to plant to be heated again

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Where can DH be used?

• In relatively dense populated areas
• Parts of the world where heat is needed
• Pipe network can be expanded tens of kilometer
  from the plant

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District heating in the world (Europe)
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Heat plants

• Heat can be generated in a variety of ways
• Coal, gas, bio pellet, industrial waste heat etc.
• Heat plants
• The only purpose of the plant is to produce heat
• Combined Heat and Power plant (CHP)
• The heat is waste from the cooling process in
  power production
• An overall fuel efficiency of 85 (compared to
  50 of power plant)
• Helps to reduce the CO2 emissions

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District heating
Electricity
Heat
Combined heat and power plant
?T Temperature difference between outgoing and
returning water
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Research question
Can we increase the overall fuel efficiency in
district heating substations by introducing
wireless sensor networks?
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Standard control method
Tf
DHS
Energy-meter
Control-central
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Wireless sensor advantages

• Distribute control system in the sensor nodes
• Easy and cheap installation, no cables!
• Easy access to new control parameters
• Redundancy with neighbors sensors
• Service Oriented Architecture (SOA)

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What have we modeled, and why?

• A complete district heating substation together
  with a house with included radiator and tap water
  circuits
• To have a tool to test new control approaches
• The main reason is to increase the temperature
  drop in the DH-network, so a higher degree of
  efficiency can be utilized in the CHP plants

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Thermodynamic model

• Model created in Mathworks Simulink
• Based on earlier models developed at Luleå
  University of Technology and Lund University

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What we have modeled
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Thermodynamic model

• Thermodynamic building
• Walls, floor, roof
• Internal mass
• Radiator system
• Radiator
• Pipes
• District heating substation
• Heat exchangers
• Control system

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Substation and house internal system
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Model overview
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Thermodynamic building
Heat balance in building
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Wall example
Layer 1
Layer 2
Layer 3
Layer 4
Indoor
Outdoor
Temperature curve
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Heat exchanger
Three sections to form realistic behavior.
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Radiator

• Use the Logarithmic Mean Temperature Difference
  (LMTD) method
• to calculate emitted power.

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Simulation results
Temperatures inside a wall
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Simulation results
Temperatures and flows in space heating heat
exchanger
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Validation
Measurement setup
HEX Tap water
HEX Radiator
M
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District heating substation
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Additional measurement installations
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Validation
- Meter communication
Bluetooth
PC with Internet access
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Validation results
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Conclusion

• Simple but powerful
• Simulate single houses and parts of networks
• Gives us the possibility to test new control
  methods

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Future work

• Test and evaluate new control methods
• Create and implement WSN to test control methods
• Implement WSN in building for real world test

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Wireless sensor

• MULLE
• Very low power (0.012 28.4mW)
• 2624mm
• Renesas M16C/62
• Bluetooth v2.0
• TCP/IP
• 60pin extension port
• Embedded temp sensor
• ZigBee extension module under development

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Work progress

• Model of district heating substation
• Validation of model
• Test and evaluation of new control methods
• Real world tests in smaller buildings
• Real world tests in larger buildings
• Evaluation

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Thank you for listening!

• Questions?