Why do heat exchangers need to be cleaned?

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Reasons for cleaning heat exchangers: A heat exchanger is a device that transfers part of the heat from a hot fluid to a cold fluid; it is also known as a heat transfer unit. Heat exchangers are common equipment in various industrial sectors such as chemicals, petroleum, power, and food, playing an important role in production. Heat exchangers can be used as heaters, coolers, condensers, evaporators, and reboilers in chemical production. There are many types of heat exchangers, but based on the principle and method of heat exchange between hot and cold fluids, they can be classified into three types: surface-type, mixed-type, and regenerative-type. Among the three types of heat exchangers, the internal-wall heat exchanger is the most widely used. During the production processes in the chemical industry, for various reasons, many heat exchanger units and pipeline systems accumulate coke, oil, scale, deposits, corrosion products, polymers, fungi, algae, and rods. Dirt and other impurities. The dirt generated will render the equipment and pipelines ineffective, resulting in a decrease in the production capacity of the equipment system, as well as in energy consumption and material usage. When scaling becomes particularly severe, the process will be interrupted, and the system will be forced to stop production, leading to various consequences. Economic losses may occur, and even serious production accidents could happen. Today, with the advancement of science, it is almost impossible to completely avoid pollution. Therefore, the cleaning of heat exchange equipment has become an essential part of industrial production, especially in the petrochemical and thermal power industries. However, due to the influence of traditional concepts and a lack of resources for cleaning technologies, most businesses and individuals still stick to traditional \"destructive\" methods and approaches such as mechanical cleaning, high-pressure water, and chemical pickling, simply believing that heat exchange is the only proper way for cleaning. Only when it affects production can it be said that the formation of scale continuously impacts a company’s energy consumption and erodes its profits. Furthermore, in an attempt to reduce cleaning costs, methods were chosen for cleaning damaged and corroded equipment, which resulted in the scrapping of that equipment and production disruptions; the costs incurred were hundreds or even thousands of times higher than those of using cleaning agents. For example, a certain cement company uses oxalic acid to clean its heat exchangers, and the cleaning time is limited to no more than 2 hours per session. Due to insufficient cleaning efficiency, the cleaning interval has been increased from once a year to once every three years, resulting in two additional shutdown periods and thereby causing losses for the company.