engleski

Implementation of Thermography for determination of air jet geometry in HVAC Systems

A method to visualize the temperature distribution in non-isothermal air jets was developed in the Laboratory for Applied Thermodynamics at the Faculty for Mechanical Engineering and Naval Architecture of the University of Zagreb. A curtain made of a material having a low heat conduction coefficient (paper, textile etc.) is inserted perpendicular to the jet outlet, along its centreline and positioned vertically. The hot or cold air stream passing along the curtain leaves on its surface a temperature track having the shape of the jet. This temperature field is recorded in stationary state using the IR thermographic camera. In the first stage of investigations the method was verified using an air jet from a circular nozzle. Here the results of the second stage of the investigations are presented, where square and rectangular air outlets were tested. The experiment consists of two measurements. First, the air jet stream is recorded with the IR thermographic camera, and then the curtain is replaced with a series of thermocouples along the jet centreline. The results are compared and show fair accordance. Thermography can be successfully applied for the determination of air jet geometry in HVAC systems. The method provides relatively easy and cheap measurements, the results of which can provide better insight and prediction of air movement paterns and thermal phenomena in HVAC systems.

thermography; determination; air jet geometry; hvac systems

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