The need for solutions that not only reduce costs but also minimize environmental impact has prompted the industry to consider more efficient alternatives. In this context, traditional cooling towers and the innovative hygroscopic cycle (HCT) emerge as two distinct approaches that merit in-depth analysis.
The question that arises is: which of these systems offers the greatest advantages in terms of operating costs and maintenance?
This article dives into a comparison between the two technologies, demonstrating how the hygroscopic cycle can offer economic benefits by reducing plant operation and maintenance significantly. HCT is thus positioned as an attractive option for those seeking to optimize their resources without compromising their commitment to the environment.
Operation and maintenance costs of cooling towers
Cooling towers are equipment designed to lower the temperature of the medium by dissipating heat to the environment through adiabatic cooling. One of the main uses in industrial processes is to cool cooling water. In power plants, cooling water is used to condense turbine outlet steam through a heat exchanger without direct contact between the two. Although effective, they have several associated costs:
Installation costs
The installation of a cooling tower involves a large initial investment. This includes the cost of the structure, pumping systems, piping and auxiliary equipment. Depending on the size and capacity, this expense can vary.
2. Operating costs
Cooling tower operating costs include:
- Energy consumption: The main electrical consumption of the cooling towers is due to the continuous pumping of water and the operation of the fans. In addition to these electrical consumptions, there is also the consumption of the treatment plant necessary to adapt the water to the quality standards required in the cooling towers. These electrical consumptions are significant and are fundamentally affected by the quality of the starting water and the chosen treatment system.
- Water consumption: cooling towers use the phenomenon of adiabatic cooling to reduce the temperature of the cooling water, and water is lost during this process in the form of steam. In addition to evaporation losses, a series of drain cycles are also necessary to prevent mineral concentration. Due to evaporation and drainage, cooling towers require large amounts of water, which translates into considerable costs in areas with limited water resources.
3. Maintenance costs
The maintenance of cooling towers is of great importance, as it ensures their optimal performance and prevents operational problems. These costs include:
- Cleaning and disinfection: Towers can accumulate sediment, biofilms and other contaminants, requiring regular cleaning. For this purpose, the use of additives such as biocides is of vital importance to maintain adequate water quality and prevent the growth of certain microorganisms, including Legionella.
- Water quality analysis: Environmental regulations require periodic testing and analysis of cooling water to ensure that no pathogenic microorganisms are present. This involves a cost that includes, among others, the collection of samples with the appropriate equipment; transport of the samples to the laboratory and subsequent study in certified laboratories following the corresponding protocols.
- Reparaciones: Los componentes de las torres, como bombas y ventiladores, pueden fallar y necesitar reemplazo, lo que incrementa los gastos. Además, los ventiladores utilizados en las torres de refrigeración suelen ser de gran tamaño, lo que dificulta los reemplazos considerablemente, siendo necesario un mayor número de operarios durante el recambio y la ayuda de medios de elevación.
4. Environmental impact
The intensive use of water and the possibility of chemical emissions for water treatment represent an environmental cost that many companies must consider. In addition, cooling towers can be responsible for water pollution if their discharges are not properly treated, which can lead to penalties and fines.
Comparison with hygroscopic cycle (HCT)
The hygroscopic cycle, developed by Francisco Javier Rubio Serrano and IMASA, represents an innovative alternative to cooling towers. Next, we will analyze the operating and maintenance costs of this technology.
Installation costs
The installation cost of HCT can be competitive compared to cooling towers, especially considering that this system can be integrated into existing plants without the need for significant structural modifications.
2. Operating costs
The hygroscopic cycle has several advantages in terms of operating costs:
- Energy efficiency: HCT has a net electrical efficiency equal to or higher than cooling towers, which translates into lower energy consumption. Its design allows it to operate at ambient temperatures above 25 °C without significantly increasing condensing pressure as in other dry technologies such as air condensers (ACC), thus optimizing energy efficiency and the amount of energy produced annually.
- Elimination of water consumption: One of the main advantages of HCT is that it completely eliminates the need for cooling water. This not only represents significant savings in operating and maintenance costs, as we have seen previously, but also reduces the environmental burden associated with water management.
3. Maintenance costs
HCT simplifies plant design, resulting in lower maintenance costs. Some of the benefits include:
- Reduced operational complexity: the hygroscopic compounds used in HCT help protect the metallurgy against corrosion and fouling. The hygroscopic cycle does not require periodic chemical treatments or analysis, thus minimizing interventions by operators or other specialized companies.
- Reduced interventions: with a system that operates efficiently and requires less technical intervention, companies can reduce their long-term maintenance costs. One factor to highlight is that the fans used in the hygroscopic cycle are smaller than those of the cooling towers, which facilitates replacement if necessary, and can be carried out by a single operator and without the need for lifting equipment.
4. Environmental impact
The hygroscopic cycle not only reduces costs, but also minimizes environmental impact. By eliminating the use of cooling water and reducing greenhouse gas emissions, this technology aligns with sustainability and climate change mitigation goals, such as those established at COP21 and COP23.
Conclusion
When comparing operating and maintenance costs between cooling towers and the hygroscopic cycle, it is evident that the HCT offers a more efficient and sustainable alternative. With a competitive initial investment, lower operating costs and reduced environmental impact, this technology is positioned as an innovative solution in power plant condensation processes. Therefore, companies that adopt this technology will not only improve their profitability, but also contribute to a more sustainable world.