Diseño de un sistema de condensación utilizando condensadores enfriados por aire (ACC) para plantas de potencia de 20 MW en Cuba, a partir del método de la Temperatura Media Logarítmica (LMTD)
Fecha
2018
Autores
González Cartas, Ranmy
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Editor
Universidad Central ‘‘Marta Abreu’’ de Las Villas. Facultad de Ingeniería Mecánica e Industrial. Departamento de Ingeniería Mecánica
Resumen
En el presente trabajo se realiza el diseño de un sistema de condensación utilizando condensadores enfriados por aire (ACC) para plantas de potencia de 20 MW en Cuba, a partir del método de la Diferencia de Temperatura Media Logarítmica, teniendo en cuenta el uso de la correlación de Zhukauskas (1972) para el flujo externo y la correlación de Chato (1960) para el flujo interno. Para ello, se investigó acerca de la novedad de estos equipos en el ámbito internacional. Se tuvo en cuenta para el diseño, la temperatura media anual del aire durante el año 2017 obteniéndose un área total de transferencia de calor de 15 541 [m2], un coeficiente global de transferencia de calor de 31,39 [W/m2-K] y una temperatura de salida del aire igual a 47,41 [ºC]. Se realiza un análisis para los días más extremos, obteniéndose para el día más frío, que el equipo es capaz de vencer la potencia requerida, en cambio, para el día más cálido, este no es capaz de vencer dicha potencia, por lo que se optó por variar la velocidad del aire y el flujo másico del mismo para vencer la potencia requerida. El principal resultado de este trabajo es el diseño del ACC, el cual se propone esté compuesto por seis ventiladores capaces de mover cada uno un flujo de 432 000 m3/h y posea dimensiones de 8 x 9,6 m. El diseño del ACC se realizó teniendo en cuenta que el costo de instalación de este aerocondensador sobrepasa en 1 613 196 USD el valor del mantenimiento de las torres evaporativas húmedas, el costo de mantenimiento del ACC equivale 3,43 % del costo de las torres evaporativas y consume 1 296 kW, equivalente a 1 447 502 USD/año.
In the present work, the design of a condensation system using air-cooled condensers (ACC) for 20 MW power plants in Cuba is made, based on the Logarithmic Mean Temperature Difference method, taking into account the use of the correlation of Zhukauskas (1972) for the external flow and the correlation of Chato (1960) for the internal flow. For this, it was investigated about the novelty of this equipment in the international scope. The mean annual air temperature during 2017 was taken into account for the design, obtaining a total heat transfer area of 15 541 [m2], an overall heat transfer coefficient of 31,39 [W/ (m2-K)] and an air outlet temperature equal to 47,41 [°C]. An analysis is made for the most extreme days, obtaining for the coldest day, that the team is able to overcome the power required, however, for the warmest day, it is not able to overcome this power, so it is chose to vary the speed of the air and the mass flow of the same to overcome the required power. The main result of this work is the ACC design, which is composed of six fans capable of moving each a flow of 432 000 m3/h and has dimensions of 8 x 9,6 m. The design of the ACC was made taking into account that the installation cost of this air condenser exceeds in 1 613 196 USD the maintenance value of the wet evaporative towers, the maintenance cost of the ACC equals 3,43% of the cost of the evaporative towers and consumes 1 296 kW, equivalent to 1 447 502 USD / year.
In the present work, the design of a condensation system using air-cooled condensers (ACC) for 20 MW power plants in Cuba is made, based on the Logarithmic Mean Temperature Difference method, taking into account the use of the correlation of Zhukauskas (1972) for the external flow and the correlation of Chato (1960) for the internal flow. For this, it was investigated about the novelty of this equipment in the international scope. The mean annual air temperature during 2017 was taken into account for the design, obtaining a total heat transfer area of 15 541 [m2], an overall heat transfer coefficient of 31,39 [W/ (m2-K)] and an air outlet temperature equal to 47,41 [°C]. An analysis is made for the most extreme days, obtaining for the coldest day, that the team is able to overcome the power required, however, for the warmest day, it is not able to overcome this power, so it is chose to vary the speed of the air and the mass flow of the same to overcome the required power. The main result of this work is the ACC design, which is composed of six fans capable of moving each a flow of 432 000 m3/h and has dimensions of 8 x 9,6 m. The design of the ACC was made taking into account that the installation cost of this air condenser exceeds in 1 613 196 USD the maintenance value of the wet evaporative towers, the maintenance cost of the ACC equals 3,43% of the cost of the evaporative towers and consumes 1 296 kW, equivalent to 1 447 502 USD / year.
Descripción
Palabras clave
Diseño, Generación de Vapor, Generación de Energía, Sistema de Condensación