Principles, Components and Classification of ACC Condensers

What is a Condenser

A condenser is a key component in refrigeration systems and is a type of heat exchanger. Its main function is to convert gas or vapor into liquid while expelling heat from the system. The working process of the condenser is an exothermic process, wherein the cooling medium (such as water or air) cools and condenses the overheated vapor of the refrigerant into liquid, carrying away the heat released by the refrigerant.

Condensers can be classified into water-cooled condensers, ACC condensers, and evaporative condensers based on the different cooling media and methods. This article will provide detailed information about ACC condensers.

Principle and Composition of ACC Condensers

ACC condensers use air as the cooling medium, relying on the temperature rise of the air to carry away the condensation heat.

An ACC condenser mainly consists of a shell, finned tube bundles, a liquid storage drum, and refrigerant inlet and outlet ports.

The tube bundles are equipped with metal helical fins (which enhance the heat transfer effect on the air side). The tube bundles can be steel tubes with steel fins, copper tubes with steel fins (or aluminum fins), and may have several flow paths. The gaseous refrigerant enters the condenser from the top, where it is divided into several paths. When an axial fan (or centrifugal fan) blows air at a speed of 2-3 m/s across the finned tube bundles, the air absorbs the heat released by the refrigerant inside the tubes, causing it to condense to liquid. The heat carried away by the air is then dispersed into the atmosphere.

Classification of ACC Condensers

ACC condensers are suitable for situations with extreme water scarcity or where water supply is not possible and are commonly found in small Freon refrigeration units. Depending on the method of air flow, they can be divided into natural convection type and forced convection type.

Natural Convection ACC Condenser

Natural convection type is used in some small domestic refrigeration equipment (such as refrigerators), where the condenser is placed in an area with natural airflow to dissipate the temperature from the surface of the condenser. The main refrigeration system in air conditioners adopts mechanical forced ventilation to cool the gaseous refrigerant in the condenser tubes.

Characteristics

• Low noise, but the heat transfer coefficient of the condenser is low;

  
  

• The cooling coil has a small liquid storage volume, with the charging amount being about 40% of the internal volume of the coil, and it has the advantages of easy operation and maintenance.

Forced Convection ACC Condenser

Forced convection air coolers, also known as air coolers, since the heat transfer coefficient of plain tube air coolers is very low, it is often necessary to set fins on the outside of the tubes to enhance the heat transfer effect on the air side. However, generally, finned tubes with small fin spacing will cause high flow resistance, necessitating measures to force air through the fin tube bundles at a certain velocity to achieve better heat exchange results.

Characteristics

• Produces noise, but the heat transfer coefficient increases;

  
  

• This evaporator is compact in structure and has good heat transfer performance;

  
  

• It can change the moisture content of the air and has a wide range of applications.