Euroheat & Power, 2. RTD Workshop, High Efficiency – Improved Building Installations and Customer Comfort, Brussels 2-3 February 2006 Control components for DHW preparation by heat exchanger M.Sc. Jan Eric Thorsen Application Center Danfoss A/S District Heating Controls 1

Euroheat & Power, 2. RTD Workshop, High Efficiency – Improved Building Installations and Customer Comfort, Brussels 2-3 February 2006 Example multifunctional controller 2

Euroheat & Power, 2. RTD Workshop, High Efficiency – Improved Building Installations and Customer Comfort, Brussels 2-3 February 2006 Why multifunctional controller ? One controller Space savings Reduced assembly costs Flexible functionality 3

Euroheat & Power, 2. RTD Workshop, High Efficiency – Improved Building Installations and Customer Comfort, Brussels 2-3 February 2006 The ”optimum” control concept depends on: Primary supply condition Demand to control performance Demand to functionalities T DHDHW 4

Euroheat & Power, 2. RTD Workshop, High Efficiency – Improved Building Installations and Customer Comfort, Brussels 2-3 February 2006 Primary supply conditions Q 1 ; T 11 = °C T T 22 = °C Q 2 = 0-0,2 l/s ; T 21 = 10°C dP = 0.5 to 6 bar T 12 = 15-25°C 5

Euroheat & Power, 2. RTD Workshop, High Efficiency – Improved Building Installations and Customer Comfort, Brussels 2-3 February Functionalities / Control performance Idle temperature (at no DHW tapping) DHW Circulation Priority function DHW/Heating

Euroheat & Power, 2. RTD Workshop, High Efficiency – Improved Building Installations and Customer Comfort, Brussels 2-3 February 2006 Q2Q2 T Q1Q1 Thermostatic controller Proportional flow controller Basic control components Differential Pressure controller 7 Q2Q2

Euroheat & Power, 2. RTD Workshop, High Efficiency – Improved Building Installations and Customer Comfort, Brussels 2-3 February 2006 Thermostatic controller Q2Q2 T Q1Q1 8

Euroheat & Power, 2. RTD Workshop, High Efficiency – Improved Building Installations and Customer Comfort, Brussels 2-3 February 2006 Thermostatic controller Q2Q2 T Q1Q1 9

Euroheat & Power, 2. RTD Workshop, High Efficiency – Improved Building Installations and Customer Comfort, Brussels 2-3 February 2006 Proportional flow controller PM controller 11 Q2Q2

Euroheat & Power, 2. RTD Workshop, High Efficiency – Improved Building Installations and Customer Comfort, Brussels 2-3 February 2006 Proportional flow controller with a temperature controller serial connected PTC controller 11 T Q2Q2

Euroheat & Power, 2. RTD Workshop, High Efficiency – Improved Building Installations and Customer Comfort, Brussels 2-3 February 2006 DCWDCW DHW Heating flow Heating return T DH Flow DH Return Temperature controller parallel connected with proportional controller plus dP controller AVTI Controller 12

Euroheat & Power, 2. RTD Workshop, High Efficiency – Improved Building Installations and Customer Comfort, Brussels 2-3 February 2006 Example AVTI controller 13

Euroheat & Power, 2. RTD Workshop, High Efficiency – Improved Building Installations and Customer Comfort, Brussels 2-3 February 2006 T T T Heating return Heating flow Combined therm. and prop. control (reduced stand by temp.) Therm. control with reduced stand by temperature control and DHW priority Other combinations 14

Euroheat & Power, 2. RTD Workshop, High Efficiency – Improved Building Installations and Customer Comfort, Brussels 2-3 February 2006 Thermostatic variants T Therm. controller with “special” position of sensor T Therm. controller with “Heat Bridge” AVTB with Gemina Heat bridge 15

Euroheat & Power, 2. RTD Workshop, High Efficiency – Improved Building Installations and Customer Comfort, Brussels 2-3 February 2006 Recommendations: constant dP and T 11, or accept seasonal adjusting ”free” setting of stand-by temperature - (additional thermostatic controller) Preventing high temperature peaks - (preventing lime scale deposits) variable dP and T 11 comfort of high standby temperature 16 Proportional controller: Thermostatic controller:

Euroheat & Power, 2. RTD Workshop, High Efficiency – Improved Building Installations and Customer Comfort, Brussels 2-3 February 2006 Recommendations: Serial coupling: Parallel coupling: variable T 11, variable dP control performance ”free” setting of stand-by temperature - (additional thermostatic controller) variable T 11, but constant dP control performance comfort of high standby temperature 17

Euroheat & Power, 2. RTD Workshop, High Efficiency – Improved Building Installations and Customer Comfort, Brussels 2-3 February 2006 Trend within compact DHW/H sub stations: 18 Towards compact multifunctional controllers Fulfilling specific demands > flexibility