What is an air cooled heat exchanger?

- May 22, 2019-

Basic introduction

The air cooled heat exchanger is a device that uses ambient air as a cooling medium to traverse the finned tube to cool or condense the high-temperature process fluid in the pipe, referred to as "air cooler", also called "air-cooled heat exchanger".


Air Cooler

Air coolers, also known as finned fans, are commonly used to replace water-cooled shell-tube heat exchanger cooling media.

With the increasing use of induction heating equipment, the user's own conditions are different, and some people pay less attention to the water cooling system of the equipment. Many users do not use distilled water according to the regulations, but use ordinary well water or tap water in actual work. Water quality has a great impact on the water cooling system and components of the equipment.


Main classification

Air coolers can be divided into the following different forms due to their structure, installation form, cooling and ventilation.

a. According to the arrangement of the tube bundle and the installation form, it is divided into horizontal air cooler and inclined top air cooler. The former applies to cooling and the latter applies to various condensing cooling.


b. According to different cooling methods, it is divided into dry air cooler and wet air cooler. The former relies on the continuous blowing of the wind by the fan; the latter enhances the heat exchange by means of spraying or atomizing the water. The latter has higher cooling efficiency than the former, but it is not widely used because it is easy to cause the corrosion of the tube bundle to affect the life of the air cooler.

c. According to different ventilation methods, it is divided into forced air (ie air supply) air cooler and induced ventilation air cooler. The former fan is installed in the lower part of the tube bundle, and the axial fan is used to supply air to the tube bundle; the latter fan is installed in the upper part of the tube bundle, and the air flows from top to bottom. The latter consumes more electricity than the former, and the cost is high, and the application is not as common as the former.


Scope of application


Mainly used in petroleum, chemical, metallurgical and other air coolers, with advantages of large air volume, high efficiency, low vibration, low noise, easy to use and maintain [2].

The fan has different types of high-efficiency, energy-saving, low-noise, anti-corrosion type, and the fan air volume adjustment mode can be divided into three types: self-adjusting, semi-self-adjusting and hand-adjusting; the cooling mode can be divided into blast type and induced air type.


The main advantage

First, improve the service life of the tube (high-frequency equipment). Ordinary water is easy to scale and needs to be cleaned regularly. Once the scaling has affected the emission power and life of the tube, the anode of the tube is easily burned through.

Second, save energy. (Taking 100KW high-frequency electron tube equipment as an example) Under the action of DC high voltage, the power consumption of the anode waterway to the ground is about 8KW for ordinary water and 70W for distilled water.

Third, reduce electrolytic corrosion. The anode high voltage forms a direct current to the ground through the water resistance. The electrolysis corrosion of the water inlet and outlet of the tube is caused, and the electrolytic corrosion rate of ordinary water is more than one hundred times that of distilled water.

The water storage tank of the air cooler is about 0.4-2.0m3 depending on the power of the equipment, and the price of pure water per ton is between 250 yuan and 300 yuan. Because the closed cycle is used, the consumption of distilled water is extremely low, which creates conditions for the use of distilled water. At the same time, if we add a certain amount of antifreeze products specially developed by our company, the winter freezing problem of high-frequency waterway can be completely solved. The use of distilled water not only increases the life of equipment and components, but also reduces maintenance costs, thereby achieving productivity and power saving.

4. The air cooler discharges heat from the electric components of the electric furnace and the softened water, and discharges heat generated by electric components such as electric furnace inductors, thyristors, and electronic tubes into the air. The heat transfer tubes with high thermal conductivity combine to form a high heat flux density, so the device has high cooling efficiency. Continuous heat exchange with air is used to transfer heat to the air, which removes accumulated heat and meets the temperature requirements of the induction heating system.


The cooling system uses distilled water to circulate in a closed circuit in an air cooler and an induction heating device, and the water quality is clean, so that the cooled electrical system does not scale for a long time and is not blocked by foreign matter. In the winter, antifreeze can be added to the cooling water to prevent the freezing of the waterway and reduce the failure of the induction heatingequipment. The cooling system does not require a pool and a cooling tower.


Use introduction

The air cooler is mainly used for cooling processing and freezing storage of meat, poultry, aquatic products, fruits and vegetables, egg milk and cold drink products in the food industry, cooling and refrigerating of various alcohols and various beverages such as beer and liquor, and also satisfying The cooling needs of process cooling materials and places in the chemical, pharmaceutical, machinery, electronics, hydropower and other industries.


The main structure

Coil

The coils of high-efficiency air coolers are made of aluminum tube aluminum sheets and steel tube steel sheets. The aluminum tube aluminum fins and the heat exchange tubes adopt the expansion joint process, the tube sheets are in close contact, the contact heat resistance is small, the heat transfer efficiency is high, and the corrosion resistance is good.

The steel tube steel fins and the heat exchange tubes adopt the integral hot-dip galvanizing process, the tube sheets are in closer contact, the contact thermal resistance is small, the heat transfer efficiency is high, and the anti-corrosion ability is strong. The fins are monolithic corrugated porous aluminum sheets or steel sheets.

A combination of fins (8, 10, 12 mm) and variable pitch (8/16, 10/20, 12/24 mm) can be used. The fins are a combination of a deep extension sleeve and a fixed distance piece, and the positioning is accurate. After the coil is made, it can be factory tested after 2.0MPa air pressure test.

Fan

The air-cooling fan is a special axial fan for the cooling fan. It has the characteristics of high efficiency, low noise and long service life. The blade adopts die-cast aluminum alloy airfoil type forward-swept twisted blades with high strength and clean surface. Use temperature -40 ° C ~ -50 ° C.

shell

The high-efficiency air cooler housing is available in high-quality steel plate or electrostatic spray paint, stainless steel plate and aluminum plate. The fan panel adopts unique design, strong rigidity, beautiful appearance, good anti-corrosion performance and long service life.