Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.
The preliminary design and testing of a portable, high-pressure humidity generator based on a corrugated-plate heat exchanger (PHE) is described. It resulted in a very simple system, consisting of a bubbling pre-saturator followed by the PHE used as a condenser. The PHE does not need to be hosted in a liquid bath, resulting in a very compact design whose operation is largely independent from a specific bath - which may be available on site – used to condition the temperature of a circulating counter-flow fluid. Experimental tests were performed on a prototype in order to demonstrate the principle and validate at an early stage the system operation. The efficiency of the PHE as condenser was assessed over a temperature range from 0 °C to 65 °C by varying input and influence parameters, such as the dew point temperature, the gas flow rate and its pressure up to 0.5 MPa. The saturation temperature of the humid gas flow compared favourably with the dew-point temperature as measured by a chilled-mirror hygrometer calibrated against a primary humidity standard. The temperature deviations were below 0.02 °C, with a maximum deviation of 0.04 °C, over the whole range of investigated temperatures and pressures.