1. EEN-E1040 Measurement and Control of Energy Systems Control II: Controlled devices, control in energy technology, complex systems Nov 7th 2016

2. Controlled devices Practically any device that can be adjusted
Valves, dampers, heaters, motors, lights…
During this lecture, devices importart in energy technology are presented

3. Valves and dampers Used for directing/regulating flows
Valves for gas/liquid flows, dampers for air flow in ducts
Can be manual or with hydraulic/electric actuators

4. Typical valves 2-way valve Flow rate control
ON/OFF (shut-off valve) or proportional (flow control valve)

5. Typical valves 3-N way valve Mixing, flow direction
ON/OFF (selector valve) or proportional (mixing valve)

6. Special valves Thermostatic mixing valve
Typically used in heating applications (domestic hot water etc.)
Mixes two flows at different temperatures and ensures output does not exceed a set temperature

7. Special valves Line balancing valve
Used for balancing systems after commissioning
Pressure measurement connections
Well-defined characteristics for obtaining desired flow rate

8. Valve parts
Stem
Body
Port A
Port B
Seat
Disc

9. Valve operation and characteristics
Valve operation described by
Kv flow factor of the valve (m3/h)
Δp pressure drop over valve
gs specific gravity of liquid (one for water)
Kvs = flow factor with fully open valve and pressure drop of 1 bar
Provided by manufacturer, important when choosing a valve
Main part of valve characteristics

10. Valve operation and characteristics
Valve authority: Δpv,open/(Δpv,open + Δpsystem)
Defines how well the valve can control the system
Should be 0.5 – 1 for good controllability
Estimate Δpsystem
Calculate required Δpv,open to get a good authority
Put the result in the equation from previous slide along with desired flow rate to get Kv for your valve
Select a valve with Kvs at least 30% larger than the obtained Kv

11. Valve linearity Graph taken from

12. Heating elements Used for converting electric power into heat
Metallic coil/wire heats up due to resistance
Heating power directly proportional to electric current passed through the element

13. Controlling a heating element
Most commonly ON/OFF control, proportionality achieved by rapidly switching the element on and off
Cheap to construct
Overshoot becomes problematic if the element is very powerful
Exercise in this course a good example
True proportional control with electric power limiters
Tyristors, TRIACs etc.
Small scale devices affordable, large power and/or 3-phase applications very costly

14. Motors Used to generate motion from electricity
Based on electromagnetism: current loop in a magnetic field starts to rotate

15. Motors - applications
Found in various sizes from micrometer to meter scale
Typical applications in control and energy systems:
Pumps
Valve and damper actuators
Cooling fans, air handling unit fans

16. Controlling motors Two main types of motors: DC and AC
DC motors utilize similar controllers as electric heaters
AC motors typically controlled with inverters
Based on modifying the frequency of the AC

17. Control in Energy Technology: Building automation
High-level controller
Supervision of systems
User interface
Low-level controllers
Subsystem control
HVAC, lighting, safety, energy, security etc.
Image from

18. Control in Energy Technology: Nuclear power plant
Reactor operation
Control rods
Pressure
Temperature
Steam
Flow
Cooling
Reactor coolant
Image from

19. Control in Energy Technology: Nuclear power plant

20. Control in Energy Technology: Nuclear power plant

21. Control of complex systems: nZEB emulator in HVAC laboratory
Process variable TE102
Brine return temperature to ground source heat pump
Controlled by
Brine-filled buffer tank
3-way valve FCV103
Plate heat exchanger connected to city water
2-way valve FCV105
Selector valve V106
Varying conditions
Buffer tank temperature
Long dead time
Nonlinearity