Mechanical Engineering - Heat Transfer, Refrigeration and Air Conditioning - Discussion

When the air temp is higher than the liquid so liquid absorbs that heat energy from the air and evaporates it and the liquid-dipped thermometer that records that temperature is called the wet bulb temp.

So when the sensible heat of air is increased it means the wet bulb temp is also increased.

Dry bulb thermometer measures simply the temperature of the air and wet bulb thermometer measures the temperature of saturated air means with 100 percent humidity at that specific temperature if we increase the temperature of air means a number of vapors that an air can store also increases.

Wet bulb temperature from the psychrometric chart starting from left to right is kept on increasing. Wet bulb is increase with the increase of sensible heat.

In sensible heating, we are adding heat so DBT increases if DBT increases WBT also increases.

Dry bulb thermometer measures simply the temperature of the air and wet bulb thermometer measures the temperature of saturated air means with 120 percent humidity at that specific temperature.

On Psychometric chart Dry Bulb temp. Increases from left to right. During sensible heating process specific humidity remains constant (i.e. process is showed by horizontal line). So as we move from left to right WBT lines (inclined lines) increases from Bottom left corner to upper right corner. So we can clearly say that WBT increases. Description can easily understood by Psychometric chart.

For the same, refer to Psychrometric Chart & draw the process for sensible heating over it. You should observe various points related to DBT, WBT, Rh, Sp. humidity, enthalpy, sp. volume lines. For the drawn process 1-2, the DBT & WBT increases. As it is a heating process, the number of water particles present in the air will be removed, hence the Rh decreases. Whereas the sp. humidity remains constant. The SP volume increases from 1 to 2. As we are adding heat to the air, its temperature & internal heat increases, which in turn increases the Enthalpy of air.

If you observe your psychrometric chart, you will observe that the enthalpy and WBT line travel proportionally. In sensible heating the path of process is along the +ve y-axis. Thus you will observe that the three lines of enthalpy, heating and WBT are proportional to each other. Hence.

You are right, I agree @Asif Ali Shah.

DBT increase then WBT also increase humidity remains constant.