Heat Transfer Fluids

Thermal fluid heating systems are indirect heat transfer systems with single-station or multi-station configurations. that control temperature conditions by circulating a thermal fluid throughout the equipment.

They are available in synthetic, synthetic-organic, and mineral formulations, each of which offers excellent thermal stability across a specific operating temperature range.

Mineral and synthetic HTFs are established viable alternatives to water or steam — and the preferred choice at temperatures above 200°C (392°F).

HTFs don’t require pressurizing at temperatures up to 350°C (662°F). Another advantage of using a mineral or synthetic fluid, as opposed to water, is that it generally has a lower freezing point

As a general rule, mineral HTFs are less restrictive in their handling requirements and less hazardous to humans and the environment than more highly refined chemicals used in synthetic fluids.

GP GasPack offers a wide range Heat Transfer Fluids to provide high performance and stability in systems with operational temperatures from -115°C (-175°F) to 400°C (750°F). Heat transfer fluids provide excellent benefits—economy, efficient operation, minimum maintenance, and precise temperature control. For more information about an specific product, contact our technical team.

Key Considerations for the Selection of HTF

Temperature

Heat transfer fluids have provided high performance and stability in systems with operational temperatures from -115°C (-175°F) to 400°C (750°F)

The operating temperature of a HTF depends on its base chemistry and purity. As a rule, mineral HTFs have a lower maximum operating temperature than their synthetic equivalents. You must match the fluid to the upper operating temperature. It is one of the crucial factors that will influence the aging of the fluid; the HTF will degrade faster if the upper operating temperature is breached for prolonged periods. The net effect is a reduced fluid lifespan.

Synthetics fluids better resist thermal degradation at higher temperatures and, therefore, are preferred at those higher temperatures

So, like any decision, the choice of HTF is a tradeoff, in this case between cost, high thermal stability and performance.

You also may need to consider a number of other properties such as viscosity, expansion rate, flash and fire points, and resistance to oxidation.

Viscosity

The objective is to get a fluid that has a low viscosity at low temperature because this affects the lowest startup temperature for the system.

Expansion rate

You must consider the thermal expansion coefficient when assessing if a particular fluid is appropriate for the size of the expansion tank in the HTF system.

Flash and fire points.

You should perform routine sampling and analysis to quantify the extent of a fluid’s thermal degradation and its closed flash point temperature. A decline in closed flash point temperature indicates a rise in the formation of short-chain hydrocarbons (“light-ends”) from thermal degradation of the fluid. Their presence in the fluid signals that a system isn’t venting effectively, and volatile components are accumulating.

You must remove these byproducts because they can negatively influence pump efficiency and represent an increased safety risk to the overall HTF system.

Every fluid, mineral or synthetic, will degrade when operating at sustained high temperature for prolonged periods. This degradation rate is faster in mineral HTFs. However, with close monitoring (for the formation of short- and long-chain hydrocarbons) and use of predictive measures to project its future health, a mineral fluid is a feasible option for processing operations.

Resistance to oxidation

Oxidation commonly is associated with mineral HTFs; polymerization products, such as sludge, form when saturated hydrocarbons react with oxygen. Contaminants such as water accelerate this process. However, using a nitrogen blanket to limit contact with air and a fine filter sieve to remove carbon and contaminants from the circulating HTF can slow the process.

Option for the Best Value

You should select an HTF based on value, which ultimately is a tradeoff between fluid cost and performance. If you need a high-temperature HTF, ensure the prospective fluid can perform adequately for prolonged periods at the necessary temperature. That requires diligently verifying and comparing heat transfer rates, fouling potential and thermal stability before purchase.

The key features of well-designed mineral or synthetic HTFs are thermal stability when operating at high temperatures for prolonged periods, good thermal transfer efficiency and high purity.

Monitoring

Once your selected HTF is in use, it’s important to regularly monitor its condition so you can predict and prevent thermal degradation over time. Synthetic fluids require just as close monitoring as their mineral counterparts because all fluids will thermally degrade when operating at high temperatures for prolonged periods. Adequate monitoring will ensure your HTF operates to its maximal potential and lasts as long as possible.

Applications

GP GasPack offers a family of heat-stable fluids developed specifically for indirect transfer of process heat. Our heat transfer fluids can meet the operating needs of virtually any single- or multiple-station heat-using system.

Available in various formulations across all temperature-operating ranges, heat transfer fluids provide proven performance, superior product life, and worry-free fluid maintenance.

Performing consistently without breakdown or corrosion, Heat Transfer fluids offer proven solutions for mitigating and managing temperature for a wide variety of applications, including:

1. Hydrocarbon processing

Oil & Gas Processing
Natural Gas Purification
Refining
Asphalt Processing & Storage
Gas to Liquid (GTL)

2. Alternative energy and technologies

Concentrated Solar Power
Organic Ranking Cycle
Biofuel Manufacturing

3. Chemical Processing

Pharmaceutical Manufacturing
Chiral Chemical Processes
Environmental Test Chambers
Specialty Chemicals Manufacturing
Chemical Manufacturing