Estimation of psychrometric parameters of vapor water mixtures in air

Abstract

In the present paper, a Visual Basic program was developed by describing the set of equations required to determine the value of seven different psychrometric properties (partial pressure of water vapor, absolute humidity, percentage humidity, relative humidity, dew point temperature, humid heat, humid volume or adiabatic saturation temperature) for mixtures of water vapor in air given the dry bulb temperature, the total atmospheric pressure and one additional parameter. Eight different cases are studied according to the corresponding input parameters. ß 2015 Wiley Periodicals, Inc. Comput Appl Eng Educ 24:39-43, 2016; View this article online at wileyonlinelibrary.com/journal/cae;

A teaching–learning tool for elementary psychrometric processes on psychrometric chart using MATLAB

“…As mentioned in Ref. , if the total pressure of moist air is assumed fixed, then only two independent properties are sufficient to fix the thermodynamic state of moist air. The total pressure is the barometric or the standard atmospheric pressure of 1.01325 bar.…”

“…Though several commercial digital resources are available on Psychrometry, their specific use in teaching/learning is scarce . Several studies have dealt with the topic of Psychrometry in a tailor‐made fashion.…”

“…Wang et al describes the development of Microsoft's Windows based psychrometric calculator using MATLAB as an upgradation over Microsoft's Disk Operating System (DOS) version of the same calculator. In a recent study by Beltran Prieto et al , a program was developed in VISUAL BASIC 6 for obtaining the psychrometric properties of air–water vapor mixture when dry bulb temperature, total atmospheric pressure and one additional psychrometric property is given as input. Several other psychrometric properties were obtained based on the set of equations described in Ref.…”

“…Several other psychrometric properties were obtained based on the set of equations described in Ref. .…”

“…A point in case is discussed by Ref. of an example of a calculation that involves determination of the adiabatic saturation temperature when the partial pressure of water vapor is given as input. The psychrometric chart not only gives the thermodynamic properties of moist air, but calculations for some of the processes can also be performed directly on the chart itself.…”