what is an air cooled chiller and how does it work?
Air cooled chiller is a type of compression chiller(Electrical chiller) whose operation is based on the vapor compression refrigeration cycle and the heat dissipation process in its condenser is done with the help of ambient air. The use of air cooled compression chillers in some regions such as middle east is well received due to the lack of water resources and other benefits of this product.
Air chillers in the air conditioning market are generally classified based on the type of compressor and condenser used in them, which are shown in the figure below.
Which type of compressor and condenser should be used in an air chiller depends on several factors, including:
1- Climatic conditions of the project site
2- Project needs and its refrigeration load
3- Financial conditions of employers
4- Technical reviews
The following video summarizes the performance and components of air-cooled chillers.
https://www.youtube.com/watch?v=Ic5a9E2ykjo
How does an air chiller work?
Compression chillers, including its air cooled type, have four main components:
- compressor
- condenser
- expansion valve
- evaporator
four mainly components works by thermodynamics cycle and final product of them working is cooling. this cooling happen in evaporator. evaporator is a kind of heat exchanger. by cooling that created in evaporator we can produce chilled water.
What is the difference between air cooled and water cooled vapor compression chiller
In fact, the only difference between cool air chillers in terms of performance (compared to water cooled chillers) is their type of condenser. As the name implies, in air compression chillers, the air condenser is used as the condensing unit in the refrigeration cycle. But in a chiller, cold water is done through the cold water that the cooling tower produces. In a separate article, we have comprehensively reviewed water chillers
How does an air cooled chiller work?
According to what happens in the vapor compression refrigeration cycle, in air cooled compression chillers, hot refrigerant vapor (at low temperature) enters the compressor and reach to a higher pressure; As a result, the temperature also rises. The hot vapor, leaving the compressor (at high temperature) then enters the condenser and is cooled by ambient air. As it will become a high temperature liquid. The refrigerant undergoes a large pressure drop as it passes through the expansion valve. So that some of the refrigerant evaporates and further reduces the temperature of the refrigerant.
As a result of above process, cold and two-phase flow of refrigerant (liquid-vapor mixture) enters the evaporator to absorb the heat of the incoming water to create cooling. In this way, the refrigerant is completely evaporated and as heat is absorbed, the refrigerant exits the evaporator in the form of hot steam and finally returns to the compressor to complete such a chiller refrigeration cycle.
What type of climate is an air chiller suitable for?
Air chiller can work in all different climatic conditions and one of its strengths is its water consumption is zero in order to reduce water temperature and create a cooling process.
Applications of air cooled compression chiller
Basically, all compression chillers are defined in terms of application in two categories of air conditioning and industrial refrigeration. However, these days, the use of cool air compression chillers, despite their higher electrical power consumption, has become very common for several reasons. Among the reasons for welcoming cool air compression chillers are:
- Easy utilization
- No water consumption
- Can be used in all climatic conditions
Air cooled chiller for air conditioning
In air conditioning systems, the cold water produced by the chiller provides the cool air flow required for cooling residential, office, commercial and even industrial spaces by circulating inside air heat exchangers (coils) such as fan coils, air conditioner coils and air coolers.
After receiving the heat, the water flow returns to the chiller and cools again to the standard ventilation temperature (7 ° C). During the cooling process of the air in the heat exchanger, the tangible and latent heat of the environment (ventilated space) is both transferred to the cold air leaving the exchanger. For this reason, compared to evaporative cooling systems (water cooler, air washer), more pleasant air is obtained.
Air cooled chiller for Industrial refrigeration
The cold water produced by the chiller is used for cooling the mechanisms and machines of production lines in a wide range of different industries. Examples of these industries are:
plastics, injection and casting, metalworking, welding, machine tools, petrochemicals, pharmacy, healthcare, food production and storage, fish farming, paper and cement, road construction and industrial cold air chillers Depending on the sensitivity and importance of stability in the factory production process and also according to the cooling requirements, they can be used centrally or non-centrally to produce cold water from -10 to 3 ° C more than the humid ambient temperature.
sources:
Tahviehnegar(translated from persian)
