Why does a lot of sweating on the walls of water pipes in summer become a sign of rain?

In summer, the walls of the water pipes sweat profusely, which is often a sign of rain. If the pipe wall is "sweating" a lot, it means that the air has a high water vapor content and high humidity, which is a precursor to rain. Water pipes "sweat.""It is not that the water in the pipe leaks, but that most of the water pipes are buried in the ground, and the temperature of the water is low, and the water vapor in the air will release heat and liquefy into small water droplets attached to the outer wall when it touches the water pipe.

Summer rainfall is generally caused by a combination of cold air and warm and moist air currents. Sultry, on the other hand, is the increase in the amount of water vapor contained in the atmosphere. Manifestation of high temperatures.

It is also a harbinger of approaching summer thunderstorms. Summer rain is mostly showers and thundershowers. The conditions for this are due to the good weather in the early days.

Temperatures are high. There is strong convection in the air in localized areas. Causes a large amount of hot and humid air to rise sharply.

caused by the formation of cumulonimbus clouds. Meanwhile. There is more hot air in the atmosphere.

Water vapor is abundant. At this time, the temperature changes little. However, due to the fact that the atmosphere contains a lot of water vapor.

It has become saturated. As a result, the moisture on the ground is not easy to evaporate. Sweat on a person's body is not easy to volatilize, so it will feel very hot and uncomfortable.

Due to the fact that the air contains more water vapor in rainy days or before rain, the average molecular weight of the air decreases, i.e. the density of the air decreases, resulting in a decrease in air pressure. The higher the temperature, the more the pressure decreases in rainy weather, so people will feel chest tightness before the rain in summer (people's inhalation is forced by the pressure of the outside atmosphere, and of course the change in the oxygen content of the air is also related).

It is generally believed that the relative molecular mass of water is relatively small, so the density of gas is relatively small, so if the proportion of water vapor is relatively high, the air pressure will be relatively low. The formula for air pressure, fluid pressure = density * acceleration due to gravity * height .

In junior high school physics, there is: "Changes in atmospheric pressure are closely related to the weather. Generally speaking, the atmospheric pressure is higher on a sunny day than on a cloudy day, and the atmospheric pressure is higher in winter than in summer.

The author believes that this problem can be attributed to the relationship between temperature, humidity and atmospheric pressure.

When an airtight container filled with air is heated, the pressure increases. The situation is different for the atmosphere, when the atmospheric temperature of a certain area rises due to certain factors, it will inevitably cause the expansion of air volume, and air molecules are bound to spread to the surrounding area. As the temperature is high, the gas molecules will move faster, which will be a factor that promotes the increase in pressure.

On the other hand, as the temperature increases, the gas molecules diffuse to the surroundings, and the number of gas molecules in the area decreases, thus forming a factor that contributes to the decrease in pressure. The actual situation is the result of the combined action of these two opposing factors. As for which of these two factors plays a major role, let's take a look at the actual situation of air pressure over continents and oceans as a function of temperature.

In summer, the temperature on the continent is higher than that on the ocean, and the air pressure on the continent is lower than that on the ocean due to the diffusion of air from the continent to the ocean; In winter, the temperature on the continent is lower than that on the ocean, and the air over the ocean spreads to the continent, which makes the air pressure on the continent higher than that on the ocean. It can be seen that diffusion plays a major and decisive role in the two factors of temperature change and molecular diffusion.

Before it rains in summer, the humidity in the air increases significantly, so when it rains in summer, a large amount of water droplets appear on the outer walls of the water pipes.

In summer, when the weather is hot and humid and the temperature is high, there is more water vapor in the air; The temperature of the groundwater in the water pipe is lower, the temperature of the water pipe is low, and the water vapor with higher temperature condenses into small water droplets on the surface of the water pipe.

Because it becomes muggy before the rain, and the temperature of the water is very low.

Before the rain, there is a lot of moisture, and it is easy to liquefy when it adheres to the water pipe.

Before a rainy day, it usually becomes very stuffy, and the moisture will be heavy and will cling to the water pipes.

This is because the humidity in the air liquefies into the water pipes in advance.

The temperature of the water pipes is lower than that of the outside, so the hot gas liquefies on it.

The air humidity has increased significantly, so it is expected to rain.

It means that there is a lot of water vapor outside, and it may rain.

Before it rains, moisture reattaches to the water pipes.

The sweating of the tap water pipe is mainly because the water vapor in the outside air is heavier, and the tap water temperature is lower than the natural temperature, which causes the water vapor to condense into water droplets (that is, liquefaction) on the tap water pipe, which forms the daily sweating phenomenon.

You can wrap a layer of insulation material on the water pipe, such as styrofoam insulation pipe, or asbestos insulation lead high-rise, or cloth strips and other materials with poor thermal conductivity can be solved.

It is a condensation phenomenon, the water temperature in the water pipe is relatively high, the temperature in the air outside the water pipe is higher, the temperature in the air is higher, the water vapor meets the colder water pipe, condenses on it, condenses to a certain extent, and forms water droplets, just like the water pipe sweating.

The water pipes are relatively cool, and the water vapor in the air is cold in the water pipes, and condenses into liquid water.

In summer, there is more moisture in the air, and the water pipes are relatively cold, and the moisture in the air will form water droplets on the outer wall of the water pipes when it is cold.

In summer, the water pipes often "sweat" is a phenomenon of (liquefaction) and (release) of heat.

Liquefaction, exothermic. Take a look at the following spaces, which will be beneficial for you to learn about the change of state of matter.

The water vapor in the air condenses into water droplets, which is a liquefaction phenomenon.

This phenomenon is normal, the sweating of the water pipe is the water beads on the outer surface of the water pipe, the standard statement is called condensation, this phenomenon is formed by alternating cold and heat, that is to say, the phenomenon formed by the high temperature outside the pipe and the low water temperature on the inner surface of the pipe, just like the principle of sweating during human exercise.

Wrapping the water pipe with an insulated hose can play a better role.

When you sweat a lot in the water pipe, it means that the level of water vapor in the air is higher, so it may be raining.

When moist air encounters cool objects near the ground, such as floors, walls, floors, furniture, etc., it is easy to condense into fine water droplets attached to it, making the home wet everywhere is very annoying.

However, air resurgence is an unavoidable natural phenomenon, and we can only think of ways to minimize the impact of resurgence on normal life and damage to our health.

The water temperature in the water pipe must be much lower than the outside air temperature in the summer, resulting in the pipe wall being cooler than the surrounding air, so there are a lot of water droplets.

When the air vapor is cooler than its own temperature, it condenses into small droplets, so it symbolizes a drop in temperature and the possibility of rain.

This is the so-called resurgence, usually the weather is cold before the rain, and the temperature rises after the rain, but there is often a "spring cold".

Because once the water pipe sweats, it means that there is a lot of humidity in the air, which means that it is about to rain.

The water vapor in the air meets the cold water pipe and condenses into water droplets that adhere to the wall of the water pipe.

No, it's that after the water comes out of the waterworks, the outside temperature is high.

No, it's just a temperature difference between the underground pipes and the surface.

Answer D Analysis: The water vapor in the air liquefies into small water droplets when it encounters the cold water pipe, which adheres to the water pipe