Final answer:
To determine the temperature and relative humidity of the air when it leaves the heating section, use the concept of dew point. The rate of heat transfer in the heating section can be calculated using the equation Q = m * Cp * ΔT. The rate of water added to the air in the evaporative cooler can be determined using the psychrometric chart.
Step-by-step explanation:
To determine the temperature and relative humidity of the air when it leaves the heating section, we need to use the concept of dew point. When air is heated, its capacity to hold water vapor increases, resulting in a decrease in relative humidity. However, if the temperature is increased and the relative humidity remains constant, the air will become supersaturated and water will condense, forming dew or fog.
For the rate of heat transfer in the heating section, we can use the equation:
Q = m * Cp * ΔT
where Q is the rate of heat transfer, m is the mass flow rate of the air, Cp is the specific heat capacity of air, and ΔT is the temperature difference between the air entering and leaving the heating section.
To calculate the rate of water added to the air in the evaporative cooler, we can use the psychrometric chart.