Evaporative condenser

Types of evaporative condensers

Unlike coolers that only condense water vapor into liquid, the evaporative condenser does the opposite by evaporating water. An evaporative condenser works to cool down hot gases until they turn back into liquids through the process of evaporation. These types of evaporative condensers include:

• Wet horizontal evaporative condenser:

  Wet horizontal evaporative condensers are arranged horizontally and often located on the ground or rooftops. These condensers leverage the force of gravity to assist in the condensation process. This horizontal positioning also aids in simplifying the layout of refrigeration or cooling systems, allowing for easier installation and integration of the condensers into the overall setup.

• Wet vertical evaporative condenser:

  Wet vertical evaporative condensers are designed to be positioned upright. Wet vertical evaporative condensers employ the same cooling technique as the horizontal type, but they occupy less space and are easily incorporated into buildings. The upward trend of the evaporative process might facilitate gas movement within the system.

• Adiabatic evaporative condenser:

  The adiabatic evaporative condensing system is a hybrid model of evaporative and air-cooled systems. An adiabatic evaporative condenser operates primarily through an evaporating cooling process. After the phase of evaporation, the remaining water cools the air via an indirect heat exchange. This process helps the system to gain more efficient energy use than others.

• Looped evaporative condenser:

  The looper evaporative condenser works similarly to the wet horizontal types. However, it is a smaller size. It is used in machinery with a limited compact space. The function of a looper evaporative condenser is similar to that of a horizontal evaporative condenser. It is still applied to cool hot gases until they become liquid.

Specification and Maintenance

The following specifications are crucial when selecting a suitable evaporative condenser for an industrial facility.

• Power: This denotes the amount of power the evaporative condenser requires to function. Power is measured in kilowatts or kW. A power requirement of 10 to 30 kW per ton is typical for most industrial systems.
• Ton capacity: This refers to the ability of the evaporative condenser to remove heat. For most industrial applications, the ton capacity typically ranges from 10 to 100 tons per unit.
• Noise level: An evaporative condenser with a low noise level will help reduce the overall noise within an industrial facility. Noise is measured in decibels. Ideally, the noise level of the unit should be less than 65dB when operating at full capacity.
• Dimensions: An evaporative condenser may come in various dimensions to meet different space requirements. The standard length of these units typically ranges from 10 ft to 30 ft.
• Operating Temperature: The working temperature range of the condenser should cover the specific needs of the industry. The temperature range should be between -10°C to 50°C (14°F to 122°F).

Maintenance

To keep a process evaporative condenser working at optimal performance for many years, manufacturers must proactively conduct preventive maintenance. The following maintenance tips will significantly extend the lifespan of an evaporative condenser and enhance its efficacy.

• Regularly check water distribution system: A regular inspection of the system helps identify any blockage or uneven water distribution. Promptly address any discovered issue to ensure that the condenser's coils receive uniform water distribution. This will improve heat transfer and prevent localized overheating.
• Pay attention to fan performance: Regularly check if the condenser fan is performing as it should. The evaporative condenser relies on the fan to draw in air for the process of heat transfer and evaporation. The same airflow will also help cool the coils of the unit. Ensure the fan is running smoothly and effectively to prevent any drop in cooling capacity.
• Biannual cleaning: Schedule for cleaning the evaporative condenser at least two times a year. This will help eliminate debris, dirt, and mineral buildup that can affect its performance. Set a reminder for cleaning the unit's water distribution system, coils, and wastewater removal parts. Consider using mild detergents during the cleaning process.
• Regularly inspect for leaks: Periodically checking the evaporative condenser for leaks can help users discover issues with the water or refrigerant lines. Promptly detecting and repairing leaks is crucial for water conservation and maintaining the efficiency of the cooling process.

Scenarios of evaporative condensers

As critical components in various industries, evaporative condensers find vast application scenarios. The traditional application of evaporative condensers are large commercial refrigeration systems. Supermarkets, food processing plants, cold storage warehouses, and commercial kitchens are just a few examples where evaporative condensers are typically used.

Moreover, as air conditioners and heat pumps are evaporative condensers for HVAC systems, they are full of scenarios. From commercial buildings, such as shopping malls and office buildings, to industrial factories, large rooftop condensers of centralized air conditioning systems are not unfamiliar. They are frequently seen in spacious, collective places where individuals gather together.

Additionally, evaporative cooling towers, often used in combination with industrial condensers, are also widely found in the power generation industry. Power plants employ evaporative cooling systems to dissipate heat generated during electricity production, ensuring optimal operating temperatures for turbines, generators, and other equipment.

Furthermore, owing to the global increasing awareness and demand for sustainable development, many industries are gradually opting for evaporative condensers as evaporative condensers are more energy-effective than other types. Therefore, the condensers can also be found in emerging industries such as wastewater treatment and desalination facilities, which typically use anti-corrosion evaporative condensers. Here, they assist in the task of removing heat.

How to choose evaporative condensers

Both evaporative and wet cooling tower condensers can help save energy, but they consume a lot of water. Condenser water pumps need to be running all the time to avoid any risks of evaporative cooling plants freezing the pipes. This will cause power bills to be on the higher side. It is necessary to evaluate the raw water treatment ability of the facility. If the water quality is not good enough, a closed-loop evaporative condenser may be a better choice.

Open-loop evaporative coolers will be exposed to the atmosphere, which increases the risk of water contamination. Closed-loop systems will prevent impurities from being mixed with water. Impurities may lead to increased maintenance demands on cooling pipes' hardware and the water treatment system.

Open-loop evaporative coolers need a reliable supply of water. The system is likely to be operationally sustainable and cost-effective if the location has easy access to water. If the water is abundant, a closed-loop evaporative cooler or an indirect cooler that recycles water may be a better choice.

Where a low carbon footprint is required, a dry cooler may be preferred without compromising equipment performance. Dry coolers use air alone to cool without water even though they are taller than evaporative coolers. They will help reduce water consumption to negligible levels, but they will not be able to reduce energy use significantly.

The selection of the right type of evaporative cooling machine should be based on a detailed analysis of the options' life cycle costs, which include repair or replacement, energy bills, water treatment, and water fees. If the required equipment does not use energy, it may need to be used less frequently or perform less well to save energy. The parts available and the technology need to be considered as well. Some may have more available parts, while some may use a better-known technology.

Operating requirements will need to be considered as well, such as temperatures and humidity levels. The site and installation will need to be analyzed to see if it is an open, indirect, or hybrid cooler system. Structural requirements include temperature changes and the need for thermal expansion joints. Power, hydraulic, and other system connections will also need to be looked at, such as electrical controls, BMS, VSD, and PLC with proper VSD programming. If the connections and controls are well integrated, it may be possible to have a system that can run self-diagnosis, data exchange, and system integration, which may help avoid system failures.

Evaporative condenser Q&A

Q1. How is an evaporative condenser different from a vertical condenser?

A1. An evaporative condenser combines the features of both a cooling tower and a refrigerant condenser. It facilitates the heat exchange process between air and refrigerant while simultaneously removing heat from the facility via the evaporation of water. On the other hand, a vertical condenser simply allows refrigerants to cool down and condense vertically, without engaging in any evaporation process.

Q2. How do evaporative condensers work in extreme weather?

A2. In extremely hot weather, the performance of an evaporative condenser may be reduced because the ambient temperature is higher than normal. However, they can still function properly, condensing the refrigerant. The water evaporation process also helps cool the air that passes through the condenser. In cold weather, the performance could be better and the water might freeze. To avoid this problem, users can install antifreeze additives to the cooling water or use a heated water tank.

Q3. What are the trends in the evaporative condenser market?

A3. The market for evaporative condensers is booming worldwide. Suppliers report growing demand for industrial and commercial evaporative condensers, especially for food processing, chemical production and refrigerated warehousing. There is also a trend toward environmentally friendly technology that uses less water and rapid, high-efficiency evaporation.