Maintaining highly efficient pumps
Market research suggests the global heat transfer fluids market size was 465.9 kilo tons in 2014 and projects significant increases up to 2022. Global Heat Transfer examines how the sampling of a heat transfer fluid (HTF) may help to maintain an efficient pump and thermal plant.
Many chemicals are used in the manufacture of HTFs and include silicone, aromatic, mineral and glycol. The speed that they are pumped around a thermal plant is effected by a number of factors including the speed of the pump and also the characteristics of the fluid itself – this includes the build-up of carbon (which increases kinematic viscosity) through the thermal degradation of the fluid over time (i.e., ageing) as well as the overall cleanliness of the fluid as a result of ongoing plant operation.
The natural ageing of the fluid can lead to the fluid thickening and this requires more energy to pump the fluid and as a result the efficiency of the plant will decrease as more energy is required to achieve the same output. This can also increase the risk of increased stress being placed on the pump and the need for the repair or replacement of its operating parts.
One of the easiest ways to manage the condition of a fluid is through routine sampling of the fluid as this is an indirect method for assessing directly the condition of the fluid and indirectly the plant. Indeed, as a fluid degrades it will form more carbon and become more viscous, and these changes can be detected in the sample of fluid taken from the plant.
In summary, the cost of routinely sampling a fluid represents an additional cost, but is a simple and effect way to avoid the longer-term detrimental effects that result from the natural degradation of fluid as it operates continuously at a high temperature over time. Sampling does, however, work to maintain energy consumption of a pump constant and thus sustain the efficiency of the overall thermal plant. Another advantage from sampling a fluid is that changes in condition can be detected early and the cost of replacing component parts of a pump may be avoided. Options used to manage carbon build-up in a HTF have been discussed in a previous article and include reductions in the operating temperature, dilution of the fluid, installation of temporary or a permanent filtration unit, the complete replacement of the HTF and reductions in the acidity of the fluid.