Today, we focus on the evaporative condenser we use — compared with the traditional atmospheric condenser, it has very obvious advantages, and at the same time, there is a small disadvantage that needs attention, as well as the corresponding solution. The whole process is simple and easy to understand, helping everyone grasp the core issues thoroughly.

I. Core Advantage: Outstanding Energy-Saving Effect, Greatly Reduced Operation Cost

First, let's understand its core advantage. Compared with the atmospheric condenser, the biggest advantage of the evaporative condenser is energy saving, and the effect is very obvious.

Why is that? Let's first look at the shortcoming of the atmospheric condenser: it needs to transport a large amount of circulating water over long distances, which leads to high power consumption of the circulating water pump. In contrast, the evaporative condenser is completely different. Its circulating water volume is relatively small, and the head of the corresponding circulating water pump is very low, so the power consumption is naturally greatly reduced.

Here is an intuitive data reference for everyone: we have measured before that for every ton of water evaporated, compared with the atmospheric condenser, the evaporative condenser can save 2-3 kWh of electricity. For equipment that needs to operate continuously for a long time, it can save a considerable amount of electricity expenses over time.

II. Key Explanation: Why Does the Evaporative Condenser Generate Heavy Fog?

Many friends will be confused why the evaporative condenser sometimes has heavy fog. Let's first tell you the conclusion: two extreme conditions are most likely to form fog — one is when the air is cold, and the other is when the air humidity is extremely high (such as the return南天 in the south, a period of high humidity and warm weather).

To understand the reason behind it, we need to first briefly understand the working principle of the evaporative condenser: its core is to dissipate heat by using "temperature difference" and "humidity difference" — the air enters from the grid at the lower part of the equipment, and the temperature and humidity when entering are completely different from those of the air discharged from the upper part; the air entering contains less water, while the air discharged contains more water. During this process, the water undergoes phase change, thereby taking away the heat generated by the equipment.

1. Why Is Fog Easy to Form When the Air Is Cold?

Let's give you a specific example: suppose the external air temperature is 0℃ and the humidity is 30%. When this air enters the evaporative condenser, it will be heated to about 40℃, and the humidity of the discharged air (that is, the saturation of the air) will reach 80%-90%, with a significant increase in water content.

Once these high-humidity air at 40℃ is discharged from the equipment and enters the cold external environment, the temperature will drop rapidly (for example, from 40℃ to 10℃ or 20℃). As we all know, the lower the temperature of the air, the less water it can hold. When the temperature drops sharply, the originally saturated air will become supersaturated, and the excess water will condense into tiny water droplets — this is the heavy fog we see.

Simply put, the essence of fog is tiny liquid droplets condensed when the air exceeds the saturation corresponding to its own temperature.

2. Why Is Fog Easy to Form During Return (High Humidity)?

Let's look at the second situation, also explained with an example: during return, the external air temperature is about 10℃, but the humidity is as high as more than 90%. When this high-humidity air enters the evaporative condenser, it will be quickly heated to about 40℃, and the saturation of the air will temporarily drop to about 60%, which can still continue to absorb water.

When the air is discharged from the upper part of the equipment, the temperature remains at 40℃, and the humidity rises to more than 90% again, with the same high water content. The outside itself is a high-humidity environment. Once these discharged high-temperature and high-humidity air meets the external humid air, the temperature will drop slightly. In addition, the humidity itself is extremely high, so it will quickly reach a supersaturated state, and then form heavy fog.

III. Common Improvement Methods: Can Alleviate, But Cannot Completely Solve

There are currently some improvement ideas for the fog problem, but everyone should be clear: these methods can only alleviate, but cannot completely eliminate the fog.

Method 1: Introduce Cold Air Halfway to Condense and Drain Water in Advance

The specific approach is: introduce cold air into the path of the discharged high-temperature and high-humidity air to make the air cool down in advance and condense part of the water droplets, then discharge the water droplets through the grid drainage device, thereby reducing the generation of fog.

However, the limitation of this method is obvious: if encountering extreme weather of "low temperature + high humidity", heavy fog will still be generated, and the problem cannot be fundamentally solved.

Method 2: Heat the Outlet to Reduce Air Saturation

Another idea is: add an additional heating device on the path of air discharge to reheat the discharged air at 40℃ to about 50℃. In this way, the saturation of the air will drop from about 90% to 70%-80%, and the possibility of fog formation will be reduced.

But this method also has shortcomings: although no obvious fog can be seen at the fan outlet, when the heated air drifts upward, it will gradually tend to be consistent with the external atmospheric temperature. After the temperature drops, it will still reach a supersaturated state and form fog, which cannot be completely eradicated.

IV. The Most Practical Solution: Adjust the Installation Position to Avoid Hazards from the Root

Since neither of the two improvement methods can completely solve the fog problem, the most effective and reliable method we currently adopt is to adjust the installation position of the evaporative condenser.

The core principle is very simple: especially in areas with high humidity and return, do not install the evaporative condenser on the upper part of the evaporator, but install it on one side of the evaporator.

The advantage of this approach is very direct: the fog will only be generated on one side of the evaporator and will not drift to the upper part of the evaporator, thus not affecting the electrical equipment, cranes and other key components on the upper part. It not only retains the core advantage of "energy saving" of the evaporative condenser, but also avoids the harm of fog to the equipment from the root.