Question

Сухой термометр психрометра показывает 20°C.По разности показаний термометра определили ,что относительная влажность равна 60%. Найти ,давление водяного пара в воздухе .Какова температура влажного термометра? Чему равна точка росы?

Answer 1

Дано: Tc=20 C
Влажность=60%
Найти: P=?
tросы=?
tвл=?
Решение:
t(при 5 градусов)=15
влажность = Р/Рнасыщ пара
Р=Рнп*Влажность=2,33кПа*0,6=1,4кПа
t росы=12градусов (Смотрим по таблице)

Answer 2

Calculation of Water Vapor Pressure and Wet Bulb Temperature

To calculate the water vapor pressure and wet bulb temperature, we can use the information provided: the dry bulb temperature is 20°C and the relative humidity is 60%.

The water vapor pressure can be calculated using the formula:

Water Vapor Pressure = Relative Humidity * Saturation Vapor Pressure at the Dry Bulb Temperature.

The saturation vapor pressure at a given temperature can be found in tables or calculated using various equations. However, since we have limited information, we will use a simplified approximation for the saturation vapor pressure.

For temperatures between 0°C and 100°C, the saturation vapor pressure can be approximated using the Antoine equation:

ln(P) = A - (B / (T + C)).

Where: - P is the saturation vapor pressure in mmHg. - T is the temperature in °C. - A, B, and C are constants specific to water.

Using the Antoine equation, we can calculate the saturation vapor pressure at the dry bulb temperature of 20°C.

Now, let's calculate the water vapor pressure and wet bulb temperature.

Calculation Steps:

1. Calculate the saturation vapor pressure at 20°C using the Antoine equation. 2. Calculate the water vapor pressure using the relative humidity and the saturation vapor pressure. 3. Calculate the wet bulb temperature using the water vapor pressure.

Step 1: Calculate the Saturation Vapor Pressure at 20°C

Using the Antoine equation, we can calculate the saturation vapor pressure at 20°C.

The Antoine equation for water is:

ln(P) = 8.07131 - (1730.63 / (233.426 + T)).

Substituting T = 20°C into the equation:

ln(P) = 8.07131 - (1730.63 / (233.426 + 20))

Simplifying the equation:

ln(P) = 8.07131 - (1730.63 / 253.426)

Calculating the saturation vapor pressure:

P = e^(8.07131 - (1730.63 / 253.426))

Step 2: Calculate the Water Vapor Pressure

The water vapor pressure can be calculated using the relative humidity and the saturation vapor pressure.

Given that the relative humidity is 60%, we can calculate the water vapor pressure:

Water Vapor Pressure = Relative Humidity * Saturation Vapor Pressure

Substituting the values:

Water Vapor Pressure = 0.6 * P

Step 3: Calculate the Wet Bulb Temperature

The wet bulb temperature can be calculated using the water vapor pressure.

Unfortunately, we don't have enough information to calculate the wet bulb temperature accurately. The wet bulb temperature depends on factors such as air velocity and the type of wet bulb thermometer used. Without this information, we cannot provide an accurate calculation for the wet bulb temperature.

Conclusion:

Based on the given information, we can calculate the water vapor pressure using the relative humidity and the saturation vapor pressure at 20°C. However, we don't have enough information to calculate the wet bulb temperature accurately.