Bachelor's thesis Thorsten Driemeier

 

Setup of a testbed for the automated thermal power measurement of air-to-water heat exchangers

Temperature distribution downstream the air to water heat exchanger Copyright: EBC Temperature distribution downstream the air to water heat exchanger

Heating, ventilation and air conditioning systems play a major role at creating a comfortable room climate. One of important task of an HVAC system is the removal of thermal loads. In modern office buildings, for example, it is likely that these loads require high cooling capacities. Despite the high cooling capacities it needs to be assured that ventilating the room does not cause draft. Active chilled beams have proven to be especially suited for this application. An active chilled beam combines an air inlet at the ceiling with an air‑to‑water heat exchanger to remove thermal loads or deliver heat, as needed.

A test bench for the measurement of the thermal power of an air‑to‑water heat exchanger in active chilled beams is constructed. The test bench offers the possibility to measure the thermal power, the pressure drop of the water and the temperature field of the air downstream the heat exchanger. In the course of this thesis the test bench is planned, constructed and built. The single components are designed to satisfy the nominal value. The test bench is operated using control software programmed in LabVIEW. This control software enables fully automated measurements. Controllers are designed for the different control variables of the system. Conclusively the function of the test bench is proven by measuring the characteristic curves of a heat exchanger for thermal power and pressure drop as well as the temperature field.