Proper coil function is an important issue regardingair-handling devices. Thus, proper modeling is important. Thepresent work deals with simulation of heating coil subsystems,especially validation on component level. The report may bedivided in three parts:
Development of an experimental setup of high measuringaccuracy and flexibility (signal shape and exchange of testcomponents)
Calibration and validation of component models, focusingon dynamic features
Measurements and simulation of how the entire heatingcoil subsystem with control behaves for airflow changes withdifferent component characteristics.A great number of studies were carried out accordingly,allowing the following conclusions to be drawn:
A great number of studies were carried out accordingly,allowing the following conclusions to be drawn:
The setup worked as planned and well-defined steps inwater supply temperature and flow rate could be obtained bysolenoid valve controls and two-way valves with fastactuators. The accuracy for each measured quantity was withinone percent.
In modeling of pipes and coils there are two aspects toconsider in order to obtain good agreement: - steadystate features should be fulfilled which may be accomplishedby model calibration to measured data - the transientbehavior should include fluid transport delays and heatcapacity effects. However, this can be done by rather simplemeans, e.g. use of nodal modeling, delay vectors etc.
Regarding the heating coil subsystem, simulations maypredict measured results reasonably well, provided -the modeling is detailed (hydraulic and thermal behavior)with calibrated models - control functions areimplemented in the simulation modeling The impact of variousmodifications in the subsystem (change of pipe length, sensortime constant, actuator set time etc) could be observed inboth measured and simulated responses.
Keywords: Air Handling Unit, dynamic component models,experimental validation, heating coil subsystem, modelcalibration, simulation, TRNSYS
Institutionen för byggnader och installationer , 1999. , xii,  p.