Heat to air update August 9th, 2017

Outline How heat to air theory and assumptions Experimental setup Flow trough heater PID control Test plan Heat loss in loads Test results August 9th, 2017

Measurements and theory Heat to air ‘measured’ Assume all heat from heater goes to water or air Tout Tin T component SAS4 Heat to air theory load August 9th, 2017

System overview SAS4 There are 2 new SSR boxes SSR1 is connected to SAS heaters and the new flow-through heater. To heaters SAS1 SAS2 SAS3 RTD out RTD in Flow meter CV pressure Chiller RTD Flow heater in RTD Flow heater out HEATER LabVIEW Software SSR heaters NI 9472 8-Ch 24 V Logic output 240 Vac August 9th, 2017 4 PRV = pressure regulating valve PT = pressure transducer CV = control valve RTD = temperature sensor HV = hand valve

Flow-trough heater The heater is connected in a vertical position to the hydraulic circuit. The temperature measured after the heater is used as the process variable in the PID controller implemented in LabVIEW The heater is provided by Loval Oy August 9th, 2017

PID ∆T (°C) SAS in 0.13 Chiller 0.90 During the first heat to air tests, the fluctuations in the inlet temperature affected the heat to air measurements. A flow trough heater was installed to control fluctuations from the chiller A PID controller was implemented with labVIEW. The PID was tuned both manually and with an automatic PID tuner The manual tuning gave best results, and the effect is shown above (Tuning numbers and constants in extra slide) August 9th, 2017

Testplan Heat to air test during steady state were completed for tree different ambient temperatures, with low (0.3m/s) and high (0.8m/s) air speed . Tests were completed without and with isolation. Tin (⁰C) 27 Heater (W) 866 mass flow (l/s) 1.35 Isolated SAS4 Ambient (⁰C) Air speed (m/s) No isolation 20 0.3 0.8 30 40 With isolation August 9th, 2017

Heat loss in loads During new heat to air test it was found that Qtot ≠ Qair + Qwater Occurred after installing the loads. We found that heat is lost trough the loads (and wave guides). Installed new RTD sensors before and after loads to measure the loss.  for the newest results (results with isolation) the heat loss in the loads were measured and accounted for in the heat to air calculation.  For the tests completed before the loads sensors were installed, the same correction factor was applied to the results. The correction factor for the loads without isolation should be measured and accounted for . August 9th, 2017

Heat loss Loads Ambient ≈ x ⁰C ≈ 37- 40⁰C Ambient under ≈ 36-37⁰C Gurder ≈ 35⁰C Floor ≈ 30⁰C August 9th, 2017

Results August 9th, 2017

Numbers to remember Chiller settings Ambient temp (oC) Chiller setting (oC) / Air 03m/s Chiller setting (oC) / Air0.8 m/s 20 25.0 30 22.0 40 15.0 PID setting One stucture All 4 stuctures P 15 110 I 0.3 0.2 D 0.05 Other settings settings Flow Scaling 50 Setpoint 27.125 Scaling factor SAS heaters 0.482

Thank you for your attention May 31th, 2017

LabVIEW August 9th, 2017

LabVIEW August 9th, 2017

LabVIEW August 9th, 2017

aa There are 2 new SSR in total. Connected to all SAS heaters for T0.1 and the flow-through heater. August 9th, 2017

PID : Proportional gain, a tuning parameter : Integral gain, a tuning parameter : Derivative gain, a tuning parameter : Error : Time or instantaneous time (the present) : Variable of integration; takes on values from time 0 to the present . * LabView software August 9th, 2017 17

PID tuning Tuning The process of setting the optimal gains for P, I and D to get an ideal response from a control system is called tuning. There are different methods of tuning of which the “guess and check” method and the LabVIEW automatic tuning VI ( Ziegler Nichols method) has been tried out. The power range provided by the flow-trough heater is 0-2000W. Manual tuning tests: Test.nr Range on heater Controller type P I D Test 1: 0-80 PI 50 0.1 Test 2: 1000 Test 3: 3000 Test 4: 10000 Test 5: 0.5 Test 6: PID Test 7: 18

Automatic PID tuning Performing interactive auto tuning in a dialog box that you use to configure the process. Includes the Auto tuning Wizard in addition to the basic PID algorithm. The PID controller was tunes for sevreal output ranges of the flow-trough heater. See table Exluded derivative response in the first tests: The derivative component causes the output to decrease if the process variable is increasing rapidly. Highly sensitive to noise in the process variable signal If the sensor feedback signal is noisy or if the control loop rate is too slow, the derivative response can make the control system unstable Automatic tuning: Test nr. Range on heater Controller type P I D Test 1: 0-30 PI 108488.075 3.194 Test 2: 0-50 48124.719 1.651 Test 3: 0-65 42937.382 1.447 19

BD test Test name Valve range Test1 43-100 Test2 50-100 Test3 60-100 70-100 Test5 80-100