The motivation that set the present project in motion has been the awareness that due to harsh environments inside the natural draft cooling towers (NDCT), there is currently no technology available to measure environmental parameters such as temperature, relative humidity and airflow velocity. Specifically, in NDCTs, the temperature and relative humidity are very high where this environment is additionally exacerbated by a poor visibility. Due to such conditions, it is difficult for a human to enter and operate in NDCTs. Consequently, the NDCT´s drop in efficiency goes unnoticed, thereby resulting in unattended damages of NDCT. This can result in significant decrease of total plant’s efficiency, increased plant‘s emissions and ultimately in financial losses.
The goal of the present project was to design a measuring unit that will, with the help of mobile units, enter the NDCT and provide accurate and reliable measurements of the temperature, relative humidity and airflow velocity. Housing was designed and manufactured to fit the chosen sensors.
The final prototype was designed in a way that it fulfilled all of the above mentioned requirements. A CREO software and 3D printer were used for design and manufacture.
Acrylonitrile butadiene styrene material was used to make the prototype. This material is resistant to demanding conditions inside the NDCT. When choosing a temperature sensor and a sensor for measuring relative humidity, fast time response and low price were required. To carry out the validation of the prototype, a wind tunnel was constructed, which ensured even air flow distribution. In the air channel, measurements were made and were used to determine the ratio of the wind speed to the number of rotations per second of the vane anemometer.
To sum up, in the course of the present project, a device installed on a mobile unit was successfully developed. It enables measurements of temperature, relative humidity and wind velocity inside NDCT. It is anticipated that the use of this device will successfully detect anomalies inside the NDCT. This will prevent reduction of efficiency, increase of emissions and financial losses.