Question

Psychrometrics) - Work on Your Own Tlowing at 1500 cfm is heated from 65°F (RH-35 conditions (db. RH ons (db, RH, wb, m) Sketch the process on the psychometri 65°F (RH-3596) at a rate of 50.000 Btu/h. Find the outlet air AMERICAN SOCIETY OF HEATING P RICERATO AND AR-CONDITIONING ENGINEERSING w ENTHALPY,

Answer 1

Air is heated at the rate of Q=50000 BTU/hr at the rate of .

m = 1500ft/min

Tidb = 65F = 18.330

From the psychometric chart

RᎫ h1 = 30 ,

Calculate the final enthalpy value.

Q= m(h2 - hı)

50000 * 0.293W = 1500 * 0.0283 (h2 - 30000) 60

50000 * 0.293W = 1500 * 0.0283 (h2 - 30000) 60

KJ <h2 = 50706.5 Kg

For sensible heating of air the process is shown in brown line on the psychometric chart.

Humidity ratio, kg water/kg dry air 50 HA Specific volume, 30 Dry bulb temperature, c 20 IN erature, °C bulb or saturation tem Specific enthalpy of moist air, kJ/kg dry air Figure A-9 Psychrometric chart for 1 atm (SI units). Source: Z. Zhang and M. B. Pate, "A Methodology for Implementing a Psychrometric Chart in a Computer Graphics System," ASHRAE Transactions, Vol. 94, Pt. 1, 1988.

It can be observed that for the outlet air ,RH2= 12%,

T2db = 380

,.

Wb2 = 180