3 IMPORTANT TIPS TO KNOW HOW TO MAINTAIN YOUR HEAT EXCHANGER IN OPTIMAL OPERATION.

Heat exchanger market

Heat exchangers are one of the most important and widely used process equipment required by modern industry. Regardless of the industry involved, it may require some type of temperature regulation, at which point the heat exchanger may play its role. According to forecasts, by 2021, the heat exchanger market will be worth 20 billion US dollars. This is a huge market, especially in the Asia-Pacific region, especially in the chemical, oil and gas, food and plastic manufacturing industries. Demand is growing rapidly.

How does a heat exchanger work

Heat exchangers can be used for heating or cooling. In the industrial field, especially in large factories and some refineries, heat exchangers are mostly used for cooling. Usually used with heat transfer fluids (HTF)-basic products, intermediate products, and final products. Many industrial processes require a certain amount of heat to function. However, great care must be taken to prevent these processes from becoming overheated. In chemical, oil and gas, food, and plastic manufacturing plants, heat exchangers are needed to keep chemicals, water, gas, and other substances within safe operating temperatures. The heat exchanger can also be used to obtain the heat released during the transfer operation, so that the heat can be better used elsewhere, improving efficiency and saving costs. Of course, heat exchangers are also used to heat and cool air in HVAC systems. That article mainly discusses the use of heat transfer fluid as a heat carrier.

Why we need to to heat exchanger maintanence work

With the widespread use of heat exchangers, how to maintain heat exchangers, improve performance, and maximize the efficiency of heat exchangers has become the focus of everyone’s attention. The factors that affect the efficiency of the heat exchanger are not always the common phenomena of leakage, scaling or clogging. Some factors are very small, but if you do not pay attention, daily inspections may damage expensive equipment and cause downtime for maintenance. These will increase the operating production costs, so understand how to maintain a heat exchanger in optimal operation is very important.

We need to understand that the composition of the heat transfer fluid of the heat exchanger can be organic or synthetic. The use of organic or synthetic high-temperature fluids is determined by the design characteristics of the heat exchanger, including related factors that affect the life of the heat exchanger (such as thermal stability, heat transfer efficiency and purity) and manufacturing costs.

Tips for how to maintain heat exchanger in optimal operation

So about how to keep your heat exchanger in optimal operation, we first need to understand several factors that affect the use of heat exchangers:

The first point of maintenance is–use the heat transfer fluid with the lowest impurity content.

Although it will not reduce the cost too much, in some industries, such as the energy industry, in the heat transfer fluids that use biphenyl and diphenyl, the degradation rate of the heat transfer fluid with a chlorine concentration of 0.1% during its service life It is slower than similar products with relatively low purity (chlorine content of 0.5%).

Similarly, in the chemical industry, heat exchangers are used to increasing the temperature of heat transfer fluids, which are used as heat carriers in chemical plants. In the working process, in addition to increasing the temperature of the heat transfer fluid, the heat exchanger may also overheat the fluid and accelerate the thermal degradation of the medium, thereby shortening the service life of the heat exchanger. Therefore, as a heat exchanger manufacturer and user, we must be familiar with the characteristics of the heat transfer fluid being used so that the heat exchanger does not exceed the recommended operating temperature of the heat transfer fluid at any stage of the working process.

The second main point of maintenance-the viscosity of the heat transfer fluid

Heat transfer fluid viscosity is inversely related to temperature. As the temperature increases, the fluid viscosity decreases. This means that when the heat exchanger starts cold, the viscosity and resistance to flow through the pipeline will be the highest. Therefore, more power is required to transport heat exchange fluid.

Therefore, when starting a heat transfer fluid with lower viscosity, the flow resistance is smaller, and it has better heat transfer performance at low temperatures. This is the first key point in the maintenance of heat exchangers. If the flow rate is insufficient, serious problems may occur when starting high-viscosity fluids, especially due to excessive local heating and accelerated fluid decomposition. Therefore, during the start-up process, it is very important to heat the heat transfer fluid to the required safe working temperature.

The third main point of maintenance-pipeline temperature

The third important factor affecting the maintenance of the heat exchanger is the continuous overheating of the pipes carrying the heat transfer fluid. If the temperature of the inner wall of the pipe is too high, it may cause the heat transfer fluid to thermally decompose and form long-chain hydrocarbons, and adhere to the inner surface of the pipe. As the coke solidifies and insulates the pipeline, the heat carrier is not cooled, the outer surface quickly scales, and even the tube melts. This is a great hidden danger to the safety of the entire factory. Therefore, daily inspection is required. The decomposition of the heat transfer fluid is largely affected by temperature. As the temperature increases, the decomposition rate of the heat transfer fluid will increase at the same time. The best way to reduce decomposition is to lower the operating temperature.

The fourth point of maintenance- cleaning

The above three points are three very important elements that may be overlooked in the maintenance process of the heat exchanger, and the fourth is the work we often do: cleaning. Then this article will also introduce how to perform efficient cleaning.

The first step is to periodically sample the fluid before cleaning. It is best to repeat sampling from multiple locations throughout the working system, especially the heat exchanger inlet and outlet. Especially large pipeline systems. Through regular sampling, you can monitor and evaluate the current operating status of the heat exchanger and predict the future service life, which is conducive to daily maintenance work.

To save costs, we recommend that users sample fluids during work rather than after the system is turned off. This eliminates the need to shut down the factory and avoid interrupting production output. This also avoids unnecessary thermal degradation during the startup of the heat exchange system. This is also called online cleaning. It can be used in combination with chemical treatment, which can effectively extend the service life of heat exchanger tubes and maintain stable performance. Also, there is offline cleaning, using bullet-shaped equipment in the tube for water spray or chemical cleaning. The two can be used in combination to restore the exchanger to the best efficiency after the fouling and fouling of the heat exchanger pipes begin to spread.

Besides, regular cleaning and manual cleaning are also effective methods we recommend. Note that the operation process needs to strictly follow the manufacturer’s instructions.

As users, the challenges of using heat exchangers usually come from knowing when to spend money on maintenance work, and how to perform maintenance through low-cost and effective methods. This is not a contradictory proposition: it is more of a good balancing act. This article shares the maintenance elements of the heat exchanger, hoping to help the majority of users find the best maintenance method to obtain maximum equipment productivity and maximum Return on investment.