The Heller towers are the most common types of power plants cooling towers، where their efficiency is very sensitive to wind. According to the general approach of cooling systems designer، Direct dry cooling (ACC) systems are more popular today in power plants located in arid areas. In Heller towers due to the empty space inside them, in this study, instead of proposing the replacement of ACC towers, the hybrid model is proposed, where steam is Directly passed into the ACC radiators without fan installed inside the Heller Tower, and condenses with a natural suction mechanism. The flow around the proposed model is investigated in three dimensions in two cases of no wind and at 8 different wind speeds with the assumption of incompressibility flow by the continuity, momentum, energy, and turbulence equations. The hybrid tower performance has been compared with the Fars power plant cooling system and it has been shown that the proposed cooling tower has performed 25% better than the Fars cooling system in no wind condition. It has also performed better in wind conditions at different speeds except for speeds above 12. 5 m/s at a parallel and vertical array with the wind of ACCs. A vertical array of ACCs performance has been better than the parallel array. Therefore, the hybrid model with a vertical array of ACCs can be efficient to replace the cooling system of the Fars power plant.

This article aims to study the thermal performances of four different natural draft cooling towers under crosswind condition. The windbreakers and the oblique exit plane have been simultaneously included in the structure of the new cooling tower. A finite volume method using SIMPLE algorithm was used to simulate the flow field around each cooling tower. The thermal performance of the new geometry has been compared with those of others for the generally investigated wind velocity profile for 10 m/s, and also two uniform wind velocities for 3 and 7 m/s. The cooling capacity of the cooling tower utilizing windbreakers and the oblique exit plane was predicted as 98.3% of the design value in the presence of generally studied wind velocity profile of 10 m/s, while that of the cooling tower utilizing windbreakers was predicted as 93.5%. Of course, the percentage of the thermal improvements of the different restoring strategies are sensitive to the profile of an approaching wind. The uniform wind velocity decreases the thermal efficiency of the cooling tower more than the distributed one, while the restoring strategies using windbreakers provide a higher percentage of thermal improvements in the presence of uniform wind velocity.

Imprecise construction work might cause imperfection in the shell of RC. hyperbolic cooling towers. By considering the three directions concrete fracture model and by using elements in Finite Element analysis which could crack in three directions, it could be shown that in imperfect shell, the thickness cracks occur at the end of the weight and thermal loads. In the other words, the inside and outside of the concrete shell separate. The number of such cracks rises up by increasing the imperfection in the cooling tower shell. This increase in number of cracks could multiple when two concavity and convexity imperfections happen consecutively. Since there is not any reinforce bar for preventing of such cracks, so it must be avoided by precise construction work and by modifying the participating thermal load factor in combining loads.

In this report, experimental investigation of waste water treatment by reverse osmosis to enable its reuse in cooling tower is presented. A polyamide spiral wound RO membrane followed by three filters as RO pretreatment (two activated carbon and one cartridge filter) and samples of Tehran refinery treated waste water have been used. The effect of operating conditions such as pressure difference, temperature and feed concentration on permeation flux, permeate concentration and fouling have been studied. The results show that continuous operation with a pressure difference of 6 bar and a temperature of 30°C are the best operating conditions. Analysis of the water treated by RO represents 95%, 100%, 93% and 97% reduction in TDS, TH, Cl – and SiO2, respectively. Comparison between the treated wastewater analysis and city water used in cooling tower as make up water shows the suitability of reverse osmosis method for the above mentioned purpose.

The wet cooling towers are one of the main consumers of water in oil and gas refineries as well as petrochemical companies for producing cooling water. If an optimum selection of cooling systems is considered in the design phase and retrofit operations in a factory, considerable water consumption savings will be achieved. For modifying existing systems to determine the best optimal option among all the alternatives available, the mathematical modeling and optimization of such plans can replace expensive laboratory or pilot plant methods previously used. In this study, using the mixed integer linear programming along with the operational experiences of the first superstructure plan, a network of cooling towers was created. In the next step, the most favorable model is regarded in two scenarios to reduce raw water consumption and cooling tower blowdown production with producing demine water (DM) required by the factory. The optimum scenario results in producing 200 m3h-1 DM water and reducing 480 m3h-1 cooling tower blowdown and 200m3h-1 raw water consumption. This scenario results are confirmed and it is now installed in ammonia plant (unit 1). The functions of NPV, IRR, and Payback are used to determine the economic criteria of the plan.

Most industrial production processes need cooling water to operate efficiently and safely. Refineries, steel mills, petrochemical manufacturing plants, electric utilities and paper mills all rely heavily on equipment or processes that require efficient temperature control. Cooling water system control these temperatures by transferring heat from hot process fluids into cooling water. As this happens, the cooling water itself gets hot before reuse it must either be cooled or replenished by a fresh supply of cold water. The aim of this study was utilizing domestic wood in cooling towers structure. For this purpose, five wood species include: hornbeam, oak, alder, poplar and eldar pine different regions with different climate, include: power plant Montazer- Ghaem near Karaj, power plant Loshan north of Iran, power plant Dorcheh Esfahan in center of Iran and petrochemical manufacturing plants Bandar-Emam from south of Iran, were selected. Sampling were conducted and treated with CCA. All samples were put in the cooling towers and were tested during the study period. (Mechanical tests such as specific gravity, static bending, compression parallel to grain and hardness). Based on this study, the mechanical properties of these species during last four years were done. At the fifth year, there weren't any virtual damages,while significant difference was achieved in terms of mechanical properties. Among the wood species, poplar and eldar pine had minimum mechanical degradation and that pinus eldarica had better quality than populus species.