Natural draft cooling tower: Analytic study for performance enhancement Raj Kumar a,⇑ , Yogesh Shrivastava a , Rashmi Rani Maheshwari a,b , Dalvir Singh a a Mechanical Engineering Department, Galgotias College of Engineering & Technology, Greater Noida 201306, India b Mechanical Engineering Department, Galgotias College of Engineering & Technology, Greater Noida and Research scholar, DTU Delhi article info Article history: Received 17 May 2020 Received in revised form 25 June 2020 Accepted 30 June 2020 Available online xxxx Keywords: Cooling tower Range Approach Effectiveness Humidity Performance Draft DBT WBT Condensate Losses abstract Research work mentioned over here deals with analytic performance evaluation, finding causes of vari- ous losses, and providing the solution for improvement of performance in existing conditions of weather. The Natural draft cooling tower of the hyperbolic structure of 210 MW generating unit of NTPC has been chosen for this purpose. Calculations have been made based on observations taken at different intervals of time in different weather conditions. The Range, Approach, Effectiveness, Loss of heat by water, Gain in heat by air, Mass flow rate of air required, etc. have been evaluated and compared with those of designed values. Results and analysis show that the effectiveness of the cooling tower is comparatively higher in winter due to high heat gain in this season. Further, it has been suggested that performance could be increased remarkably by increasing the height of the cooling tower and using eliminators of correct design so that various types of losses could be reduced. Ó 2020 Elsevier Ltd. All rights reserved. Selection and Peer-review under responsibility of the scientific committee of the 2nd International Con- ference on Future Learning Aspects of Mechanical Engineering. 1. Introduction 1.1. Overview This research work studies the natural draft cooling tower at NTPC Dadri. The performance evaluation and reduction in losses is the main objective. The results are taken as a mean month aver- age in summer and winter from a cooling tower of 210 MW power generating unit. The height of the cooling tower is 117 m, fill depth 10 m and spray zone height 11 m. The exhaust from the turbine is condensed and the condensate is sprayed from a height of 11 m through fill depth in the cooling tower. The exchange of heat is in the counter-clockwise direction and so it is referred to counter flow cooling tower and since the heat transfer takes place naturally i.e. due to buoyancy effect, it is called a natural draft cooling tower. During the process, the condensate gets cool and hot humid air exit from the top of the tower. There is a huge amount of loss of water in the form of evaporation which draws attention to be controlled. 1.2. Performance parameters Range: Range of cooling tower means the ability of water to reduce its temperature. Mathematically, Cooling Tower Range (°C) = [Cooling water inlet temperature – Cooling water outlet temperature] = ðt h  t c Þ (1) Where,t h ¼ Cooling Water (CW) inlet temperature, i.e. hot water temperature, and t c ¼Cooling Water (CW) outlet tempera- ture, i.e. cold water temperature Approach: Approach is defined as the difference between cold water temperature and wet bulb temperature of ambient. For bet- ter performance, its value should be. Mathematically, Approach (°C) = [Cooling water outlet temperature(cold water) – Wet bulb temp of ambient]= (t c  t wb Þ (2) Where, t c ¼ Cooling Water (CW) outlet temperature, i.e. cold water temperature and (t wb Þ = Wet bulb temperature of ambient air https://doi.org/10.1016/j.matpr.2020.06.591 2214-7853/Ó 2020 Elsevier Ltd. All rights reserved. Selection and Peer-review under responsibility of the scientific committee of the 2nd International Conference on Future Learning Aspects of Mechanical Engineering. ⇑ Corresponding author. E-mail address: raj.kumar@galgotiacollege.edu (R. Kumar). Materials Today: Proceedings xxx (xxxx) xxx Contents lists available at ScienceDirect Materials Today: Proceedings journal homepage: www.elsevier.com/locate/matpr Please cite this article as: R. Kumar, Y. Shrivastava, R. R. Maheshwari et al., Natural draft cooling tower: Analytic study for performance enhancement, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2020.06.591