Thermal Oil Heat Recovery
Dear Readers,
As we have already learnt in our last technical info, water has excellent properties as a heat transfer medium.
Unfortunately, these advantages can only be used in a relatively small temperature range.
A common alternative for high- but also low temperatures are “organic heat carrier fluids”, the so-called “Thermal Oils”.
These media are designed to transport extreme temperatures in liquid condition.
In this article:
- Discover how organic heat transfer fluids revolutionize high-temperature applications.
- Thermal oil heat recovery systems and their pivotal role in energy efficiency.
- Advantages of thermal oil plants for sustainable energy solutions.
- FAQs
The following table shows the wide temperature range that Micocal Heat Transfer Fluids can cover.
Since the temperatures for these systems are usually above the acid dew point or the freezing point of the heat carrier, we must pay particular attention to the upper limits, such as: “Admissible Film Temperature” and “Admissible Operation Temperature” of the fluid. While the film temperature is more a theoretical figure, used to describe the temperature of the oil film, which is in contact with the pipe wall, the operation temperature is one of the main criteria for the evaluation of the right heat carrier fluid. Other important figures are viscosity, specific heat capacity, steam pressure and heat conductivity, toxicological properties and hazard classes. Depending on the process, which will be heated, other specific properties like “Food Grade” or “Halal” certification can be another important parameter for the selection of the thermal oil.
In contrast to water, at which a high pressure builds up above 100°C, organic heat transfer media can be heated very strongly without a significant vapor pressure developing. Temperatures of up to 350°C can be transferred in liquid condition, in non-pressurized systems with these media. Theses capabilities open a range of advantages in high-temperature applications. Starting with the lower costs for the installation of non-pressurized systems through simplified approval procedures to outstanding flexibility and simple but exact temperature control. There are no chemicals or thermal energy needed for water treatment, organic heat transfer media are non corrosive, usually do not freeze and so on…
Additionally, in many cases, the heating surfaces in consumers cannot withstand the high pressures that would arise at similarly high temperatures in hot water steam systems.
Besides of all the advantages of organic heat transfer media, hydrocarbon chains can be decomposed by thermal overload or oxidation. But these potential disadvantages can be avoided by a professional and accurate design of the heat transfer system. The internationally applicable standard for the construction and equipment of such system is DIN 4754. Here, the materials to be used, dimensioning of piping and apparatus, system design as well as the safety engineering execution are regulated in detail.
If the plant is well designed and the maintenance is carried out properly, the service life of the Thermal Oil (Heat Carrier Oil) can easily be as long as the service life of the plant, which can easily reach more than 20 years.
Please note, that the “Operation Temperature” is the average temperature of the oil in you plant (feed line temperature + return line temperature / 2). If your plant is operated for example at 280°C feed line temperature and the return line temperature is 250°C, the average oil temperature would be 265°C.
If, for example, the admissible temperature of your oil is 320°C (normal figure for mineral heat carrier oil), the service life of the oil would already be more than 32 years.
In principle, Thermal Oil Heat Recovery Plants are very similar in design to Warm Water Heat Transfer Plants. The heat transfer fluid is circulated in a closed circuit by a pump from the heat recovery unit to the consumers and back. The thermal expansion of the oil is compensated by an expansion tank, which also provides the static pressure to the pump. Depending on the system concept, a safety valve may be required to protect the heat recovery unit from overpressure.
Due to the fact, that thermal oil plants are not pressurized, standard materials that do not have to withstand high pressures can be used for the pipes and apparatus. Since it is a closed circuit, no treatment is required. refilling the oil is only necessary to compensate for decomposition and minimal losses due to the mechanical seal of the pump.
As mentioned before, the measures to maintain the correct temperatures and to avoid oxidation is very important for the lifetime and to avoid unplanned downtime of Thermal Oil Plants. In one of our next technical information letters we will describe the important criteria and the best equipment for the design and execution of Heat Transfer Plants, with organic media, in detail.
FAQs (Frequently Asked Questions)
What are thermal oil heat recovery systems, and why are they important?
Thermal oil heat recovery systems utilize organic heat transfer fluids to capture and utilize wasted heat, improving energy efficiency and reducing environmental impact in industrial processes.
What factors should be considered when selecting thermal oil for heat recovery systems?
Factors such as admissible temperature, viscosity, safety considerations, and compatibility with process requirements are crucial in selecting the right thermal oil for optimal performance and longevity. Additionally, specific requirements such as “Food Grade” or “Halal” certification may also be important depending on the application.
What are organic heat carrier fluids?
Organic heat carrier fluids, commonly known as thermal oils, transport heat from a heat source to a consumer in liquid condition. Organic heat transfer media can handle high temperatures of up to 350°C without pressure. This feature offers advantages in high-temperature applications, including lower installation costs and simplified approval procedures.
What is the service life of thermal oil in heat recovery systems?
With proper design and maintenance, the service life of thermal oil (heat carrier fluid) can easily match or exceed the service life of the plant, reaching more than 20 years. Factors such as operation temperature and maintenance practices play a significant role in determining the longevity of the thermal oil.
How are thermal oil heat recovery plants designed and operated?
Thermal oil heat recovery plants operate in a closed circuit, where the heat transfer fluid is circulated by a pump from the heat recovery unit to consumers and back. The thermal expansion of the oil is compensated by an expansion tank. Regular maintenance, including monitoring and maintaining correct temperatures, is essential to avoid unplanned downtime and ensure optimal performance.
PT Maxxtec Teknologi Indonesia has been established 2014 to bring innovative European Technologies to South East Asia. Our aim is to improve energy efficiency of local productions in order to increase cost efficiency and to help protect the environment.
We are a team of very experienced german Specialists and highly educated local engineers, who design solutions based on the latest german Technology, with highest german Quality Standards, while producing here in South East Asia.
Our Office is located in South – Jakarta, where we do research, development, engineering, design, project management, production supervision, site services, as well as spare part-, maintenance- and repair services for all of our products and solutions.
We would be pleased to assist you with any questions.
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PT Maxxtec Teknologi Indonesia
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12210 Jakarta Selatan
Indonesia
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