PLATE HEAT EXCHANGER USED AS EVAPORATORS

摘要

The research included in this paper was performed in the Thermodynamics Laboratory, part of the TechnicalrnUniversity of Civil Engineering, Bucharest. The research refers to the evaporation of ammonia in plate heatrnexchangers, used for liquid cooling. The authors present a theoretical modeling of convective heat transferrncoefficient. The convective heat transfer coefficient of evaporating ammonia in narrow spaces is calculatedrnusing different correlations.rnSimultaneously, the authors present the experimental modeling, together with the measured values and therndata acquisition system. Further a comparison is made between the experimental and theoretical data, aimingrnto confirm the correlations’ validity for both the geometry and the given functioning conditions of the platerntype evaporator. The conclusions section recommends the use of the plate heat exchanger as an evaporator, inrnoperating conditions similar to those used in the experiment. The present interest of this paper comes also fromrnits focus on ammonia – a natural and ecological refrigerant – having no ozone depleting potential and lowrnglobal warming effect.