EFFECT OF DIFFERENT SATURATED WATER VAPOR PRESSURE FORMULAS ONOUTDOOR WET BULB TEMPERATURE CALCULATION

The wet bulb temperature was calculated by trial method. Goff-Cratch, Hyland-Wexler, Magnus-Teten, Murphy-Koop, modified Buck and Buck were used to calculate the saturated vapor pressure. First of all, 1 120 sets of data were used, including dry bulb temperature range of -15~40 ℃, relative humidity range of 5%~100% and atmospheric pressure of 1 013.25 hPa. By comparing the calculated wet bulb temperatures obtained by the six calculation formulas of saturated water vapor pressure with the wet bulb temperature obtained from the h-d diagram, it was concluded that when the relative humidity was 5%, 30%, the maximum difference of the average error of the wet bulb temperature was 0.01; when the dry bulb temperature was -15~0 ℃, the maximum difference of the average error was 0.01; the average error was 0.59, and the root mean square error was 1.02; then, based on the dry bulb temperature, relative humidity and atmospheric pressure observed manually, comparing the calculated wet bulb temperatures obtained by the six formulas of saturated water vapor pressure with the manually observed wet bulb temperature, it was concluded that the calculated wet bulb temperature under the six formulas of saturated water vapor pressure was equal and had the same error. Finally, based on the comparison of the two results, it could be concluded that: with the accuracy of error less than 0.01, the six calculation formulas of saturated water vapor pressure had no influence on the calculation of outdoor wet bulb temperature; for the calculation of outdoor wet bulb temperature, one of the six calculation formulas of saturated water vapor pressure could be selected for the calculation of saturated water vapor pressure.