Thermal fluids for renewables applications
Advice on heat transfer fluids for alternative energy applications
As we reduce global reliance on fossil fuels, the renewables and alternative energies sectors have gained momentum. Processes such as hydrogen production, solar power generation, combined heat and power (CHP) and biofuels have emerged as promising alternatives.
Heat transfer fluids can play an integral role in the performance and efficiency of renewables technology.
Global Heat Transfer sells a range of specialist heat transfer fluids designed to optimise efficiency, provide thermal stability and deliver high levels of performance. These thermal fluids can provide years of good service in applications including:
- Biofuels
- Biomass
- Combined hat and power (CHP)
- Gasification
- Hydrogen generation
- Organic Rankine Cycle (ORC)
- Solar
- Recycling materials
Why use heat transfer fluids in alternative energy processes?
Thermal fluids can enhance the performance of renewable energy systems. A heat transfer system can optimise energy use and improve efficiency by capturing, storing and transporting thermal energy.
Heat transfer systems can also capture and store excess heat that would normally go to waste, improving overall efficiency of a system.
Why are heat transfer fluids better than steam?
An alternative approach to heat transfer fluid technology is a water and steam-based system. However, to reach the required operating temperatures, steam-based heating systems create a lot of pressure, which can increase the risk of breakdowns and accidents in a facility.
Thermal fluid systems, on the other hand, use specialist fluids designed to operate at high temperatures for long periods of time, without the need for high pressure levels. As a result, these systems require less maintenance in general when compared to their steam-based counterparts.
Which thermal fluids are best for alternative energy applications?
Synthetic thermal fluids are typically a good choice for renewable energy generation applications. Synthetic fluids, such as Globaltherm® Omnitech and Globaltherm® Syntec, are engineered to operate effectively and provide thermal stability across a broad temperature range.
Synthetic heat transfer fluids sometimes have lower viscosity than mineral-based ones, especially in colder environments. This enables the fluid to circulate more easily through a system, improving efficiency and reducing energy consumption. In reality, all thermal oil systems should be designed with the parameters of the intended oil in mind.
Renewable energy systems may contain incompatible metals, and choosing a corrosion-resistant thermal fluid will help ensure longevity.
When choosing a specific synthetic heat transfer fluid, consider the specific requirements of the application and system, such as the operating temperature range, cost, environmental impact and system compatibility.
How can thermal fluids improve waste heat recovery?
Waste heat is a by-product of many industrial processes and power generation technologies that is typically released into the environment. Heat transfer systems can help businesses improve waste heat recovery by capturing and reusing excess thermal energy. This can enhance overall energy efficiency and reduce the environmental impact of the business.
Heat transfer system design is crucial for effective waste heat recovery. The design will determine how the system captures, transfers and uses thermal energy created by industrial processes.
Together, we can create a system where components can effectively transfer heat to maximise energy recovery. Additional features, such as insulation, can minimise heat loss elsewhere and reduce energy costs.
Heat recovery systems
Industrial waste heat refers to any energy generated in industrial processes that is not used. Heat is typically wasted to the immediate environment, but businesses can benefit from recovering and using this energy to improve sustainability and reduce their carbon footprint.
Heat recovery technologies such as Organic Rankine Cycle systems, capture the heat from biomass systems, geothermal sources or waste heat from other processes to produce electricity. Combined heat and power (CHP) systems can effectively capture and use heat energy from power generation equipment.
To effectively recover low-grade heat in both applications, engineers should choose a heat transfer fluid with precise temperature control, excellent thermal stability and a suitable boiling point.
Recycling
Heat transfer processes are integral to the efficient recycling of various materials, including glass, plastics, cooking oil, lube oil and aluminium.
Thermal fluids with a wide operating temperature range ensure thermal efficiency when melting, treating and cooling materials during the recycling process. Manufacturers can control the temperature of the fluid to ensure precision, relieving internal stresses during melting, ensuring the material reaches the right temperature to meet the mechanical properties required and controlling the cooling process to minimise defects.
A heat transfer system can also capture waste heat generated during the recycling process to provide energy for other processes or reuse it to preheat raw materials, maximising efficiency.
Heat transfer fluids
Maintaining thermal fluids in renewables applications
Maintaining thermal fluids in alternative energy applications is crucial for sustaining the efficiency, longevity and reliability of systems, as well as to remain compliant with regulations such as the Dangerous Substances and Explosive Atmospheres Regulations (DSEAR 2002) and the UKEX Regulations, formerly known as ATEX.
Regular monitoring of thermal fluid quality with periodic sampling and analysis enables engineers to monitor condition and identify issues before they impact production. Also, engineers can identify data trends, which can be key to reducing downtime and the costs associated with maintenance. Often, these could have been prevented earlier with effective intervention. If any changes in fluid quality appear, engineers can seek our support.
For example, as a fluid reaches the end of its lifespan it can form volatile light ends that reduce the flash point — the minimum temperature at which vapours ignite. To manage this, we can provide a flash point management service to remove light ends from the system.
Engineers should also regularly walk the system to check core system components, such as the gauges and pipework. Keeping pipes insulated helps to maintain heat transfer efficiency and system performance. Also, engineers should pay close attention to pumps, listening for adverse noises and vibrations.
As a part of Global Heat Transfer’s preventative maintenance programme, Thermocare, you can receive 24 hour engineering support for your systems.
Thermal fluids for biofuels
Biofuels, such as ethanol and wood pellets, are a common alternative to fossil fuels. Nearly every step of biofuel production requires efficient heating at temperatures that must be maintained for long periods of time.
The initial production, transport, refining and recycling of oil and gas products such as biofuels require the use of heat transfer fluids. Refineries also use heat transfer systems to heat reboilers and columns for the distillation process.
Global Heat Transfer has worked with companies in biofuel manufacturing for over 30 years to understand what fluids will best suit an individual application. Globaltherm® heat transfer fluids ensure the high thermal stability and precise temperature control required for optimum yield.
Heat transfer fluid for biomass applications
When converting waste from organic materials into energy, biomass fuel systems require precise temperature control to ensure maximum energy output.
The combustion process occurs at extremely high temperatures, so it is best to use a high temperature thermal fluid with high thermal stability. High thermal conductivity and low viscosity can also help improve circulation and optimise the process.
Heat transfer fluids for gasification
The gasification process requires engineers to heat carbon or organic materials in a controlled environment to prevent complete combustion.
To reach and maintain the appropriate temperatures for gasification requires precision. Heat transfer fluids can maintain consistent temperatures for prolonged periods in various parts of the gasifier, such as the reaction chamber or syngas cooling system.
Thermal fluid can also capture waste heat from different stages of the gasification process for use elsewhere in the plant. Diverted heat can be used for other industrial processes in the facility or applications such as driving turbines for electricity generation.
Thermal fluids for hydrogen production
Indirect heat transfer can facilitate the various chemical processes involved in hydrogen generation, such as gasification and water-splitting reactions. Some of these processes require extremely high temperatures, which steam based systems would require high levels of pressure to reach.
Thermal fluid-based systems, however, can operate effectively at a broader range of high temperatures without the need to increase pressure in the system. These fluids can therefore be used for a range of processes, providing more flexibility to engineers.
Heat transfer fluids also offer better temperature control, improved heat transfer efficiency, corrosion resistance and overall process optimisation.
Heat transfer fluids for solar
Concentrated Solar Power (CSP) plants require the use of a heat transfer fluid designed to work to appropriate temperatures for prolonged periods.
Heat transfer fluids can be used in a range of CSP systems, including parabolic trough systems, solar power towers, dish systems and Linear Fresnel reflectors. A heat transfer fluid can also be used to store thermal energy absorbed from sunlight, allowing consistent power provision despite the intermittent supply of sunlight.
Globaltherm® has a range of heat transfer fluids for use in CSP plants, as well as molten salt for energy storage. These specifically designed fluids work at precise temperatures for prolonged periods of time. The range is highly efficient and each product has different qualities to suit a range of applications. These fluids also have superior anti-oxidation properties for optimum performance.
For more advice on matching a thermal fluid to your application in the renewables or alternatives energy industry, contact Global Heat Transfer.
