Cooling Tower Research Articles

Community Legionella outbreak linked to a cooling tower, 2022.

Thirty-five laboratory-confirmed legionellosis cases were reported to the Simcoe Muskoka District Health Unit (Ontario, Canada) between September 27, 2022, and October 15, 2022, resulting in one death and 29 hospitalizations. This article describes the Legionella outbreak and highlights activities for managing the outbreak, including various environmental and infrastructural controls associated with the public health response and some of the unique challenges and potential solutions to mitigate future outbreaks. All cases of legionellosis were reported to and investigated by the local provincial health unit. Within a 6 km radius around the community, 27 cooling towers (CTs) were identified as potential sources of Legionella. Environmental samples were collected from 19 CTs and a long-term care home. Of the 35 cases, 29 (83%) were hospitalized (including three long-term care residents) with two requiring intubation/ventilation. Of the five sputa (clinical isolates) collected from confirmed cases, four tested positive for Legionella pneumophila (one was positive for L. pneumophila serogroup 1-with the same sequence type as one of the CT isolates). Education and recommendations were provided by the local provincial health unit to operators to improve CT operation. Detection and management of community legionellosis outbreaks associated with CTs involve resources and time to properly identify and control risks. Measures for community risk mitigation included coordinating with provincial and community partners, developing methods to rapidly identify CTs as a likely source of infection and applying operational/maintenance/testing standards for CTs to control bacterial growth and minimize the dispersion of contaminated aerosols.

Research on energy consumption analysis of air conditioning and refrigeration equipment based on perceptron model

Abstract This paper mainly studies the energy consumption of air conditioning and refrigeration system from the perspective of the dynamic operation of air conditioning systems and selects the energy consumption of a chiller system, cooling tower system, chilled water pump system and fan coil system, which affect the energy consumption of air conditioning system, as model variables. An integrated learning method based on a multilayer perceptron is proposed to integrate spatial features with temporal features, and a spatio-temporal prediction model for air conditioning energy consumption analysis is established under the Seq2Seq framework, and then the input curves of the four variables with load change under the optimal operation of the air conditioning system under dynamic load are derived. The results show that the deviation between the simulated value and the measured, calculated value of the energy consumption analysis model of air conditioning and refrigeration equipment based on the multilayer perceptron is within 5%, which can effectively and accurately predict and reduce air conditioning energy consumption by 15% to 20%. The maximum energy-saving efficiency can reach 30% when the air conditioning system is in optimal operation under dynamic load, and the energy-saving effect of the chiller, chilled water pump and cooling water pump is relatively significant. The research results of this paper have a certain reference value for reducing the energy consumption of air conditioning systems in practice.

DESIGN OF BIOGAS COOLING PROCESSING FROM POME FOR (CSTR) CONTINUOUS STIRRED TANK REACTOR SYSTEM

POME (Palm Oil Mill Effluent) can be used as for biogas production, with the main content of (65%) methane gas (CH4) and 35% Carbon Dioxide (CO2), H2S, and H2O gases. Apart from being a gas fuel and a source of electricity generation, biogas from POME waste as well as a waste processor becomes more environmentally friendly (according to quality standards). In order to support the process production of biogas from POME by using Continuous Stirred Tank Reactors (CSTR), it is necessary to decrease POME’s temperature to meet the requirements of the reactor operating conditions. Cooling process by using a Cooling Tower through direct contact between fluids can be a good alternative to be used as a POME cooling method because of its effectiveness in heat exchange and smaller area needed than an open ponds. The type of cooling tower used is the Induced Draft Cooling Tower. In cooling tower design, the steps involved in determining the basic design, calculation of tower dimensions, basin, fan power, losses, and cooling air requirements. Based on the calculation, the tower dimensions determine a height of 5 m, length of 3.6 m, and width of 2.5 m, while the basin cooling tower dimensions determine a height of 2.7 m, length of 3.6 m, and width of 2.5 m, fan power of 5 hp. The cooling air requirement for the POME cooling process is 82,895.14 kg/hour.

Study on heat transfer and water saving characteristics of a new cooling tower condensation module

Cooling towers generate large amounts of water loss during operation due to evaporation, drift and drainage and the air passing through the cooling tower is hot and humid and tends to mix with the cold and dry ambient air to form a visible white mist, resulting in poor heat transfer. In order to mitigate this effect, a new condensing module was developed and an experimental platform was set up to carry out numerical simulations and experimental studies on heat transfer, water saving and resistance characteristics. The results showed that the special structure of the new condensing module can effectively improve the heat transfer effect in the tower and reduce water losses and white mist at the top of the tower. At different flow rates, the temperature difference between the inlet and outlet of the wet heat channel of the new condensing module is 12.26% higher than that of the conventional condensing module, and the water vapor recovery rate is 16.81% higher; at different temperature differences, the temperature difference between the inlet and outlet of the wet heat channel of the new condensing module is 13.93% higher than that of the conventional condensing module, and the water vapor recovery rate is 15.45% higher. Therefore, the new condensation module provides a new method for cooling towers to improve heat transfer efficiency, as well as to remove mist and save water.

Research on Gravity Energy Saving Reconstruction Technology of Circulating Cooling Water in Mechanical Ventilation Cooling Tower of a Steel Plant

There is a height drop in the rain area of the circulating cooling water in mechanical ventilation circulating cooling towers, resulting in the ineffective use of gravitational potential energy. High-level water collection is an effective way to reduce the energy consumption of the cooling tower. Based on this, aiming to solve the gravity energy waste problem of circulating water in the cooling tower of a steel plant, this paper innovatively puts forward the high-level water tank to utilize the energy-saving transformation technology of turbine power generation and pump power saving. Additionally, this paper explores the energy-saving effects of the two methods under different height drops. The results show that the maximum utilizable rain area height of the cooling tower is 5 m, while the annual electric energy output of turbine technology can reach 4.704 million kW·h. The high water collection technology can reduce pump power consumption and save up to 7.35 million kW·h per year of electric energy, maintaining a more significant energy-saving ability compared with the turbine power generation technology. In terms of performance, the design of a high-level water tank is to help eliminate rain areas and improve the heat exchange efficiency of water and gas, so that the water temperature of the outgoing tower is 0.13 °C lower than that of the conventional cooling tower. Meanwhile, the ventilation resistance in the rain area is weakened, the resistance coefficient can be reduced by about 40–50%, and the noise can be reduced by about 10 dB (A) under the action of the water collection device. According to the economic evaluation, the total cost of turbine power generation technology is 0.563 million dollars and the total cost of high-level water collection technology is 0.446 million dollars. The cost can be realized within two years, but the high-level water collection technology avoids additional pump maintenance costs and has better economy. This study provides a theoretical basis for the transformation and optimization design of mechanical ventilation cooling towers, and has important reference value.

Recent Progress in Fill Media Technology for Wet Cooling Towers

Cooling towers are extensively utilized in diverse industries for efficient heat dissipation. Fill media are a critical component, facilitating heat and mass exchange between water and air, impacting overall cooling tower efficiency. Given its vital importance, this study comprehensively reviews recent advancements in fill media technology, illuminating cooling tower technology progress and exploring the effects of different fill media configurations and materials on cooling tower performance. It should be noted that the majority of research is focused on the Range of 2.5 °C to 25 °C and Approach of 1 °C to 9 °C. Through comprehensive analysis and evaluation, the effects of various fill media on heat transfer efficiency, water cooling capacity, and energy consumption are intensively summarized. By understanding these effects, engineers and designers can make rational decisions to optimize cooling tower performance and ensure efficient heat dissipation. Notably, in some reported cases, new fill media enhanced cooling range, effectiveness, and the Merkel number by 28%, 85%, and 131%, respectively. Ultimately, this paper serves as a valuable resource for academics, researchers, and professionals in the field of cooling tower design and thermal management. The insights provided in this study can help industries achieve greater energy efficiency, sustainability, and overall operational excellence.

THE EFFECT OF TEMPERATURE AND WATER CONDUCTIVITY IN HOT BASIN TOWARD EFFECTIVENESS OF COOLING TOWER ON UTILITY UNIT PT. X

THE EFFECT OF TEMPERATURE AND WATER CONDUCTIVITY IN HOT BASIN TOWARD EFFECTIVENESS OF COOLING TOWER ON UTILITY UNIT PT. X

The Synergy Between Corrosion and Fatigue: Failure Analysis of an Aerator and a Cooling Tower

The Synergy Between Corrosion and Fatigue: Failure Analysis of an Aerator and a Cooling Tower

Mathematical Model and Experimental Data for Water Cooling in Counterflow Film Cooling Towers

Mathematical Model and Experimental Data for Water Cooling in Counterflow Film Cooling Towers

A large-scale stochastic simulation-based thermodynamic optimization for the hybrid closed circuit cooling tower system with parallel computing

The emerging multi-mode cooling tower can cool down the circulating water by flexibly switching the operating modes according to varying weather conditions. Herein, a computational framework for addressing a large-scale stochastic simulation-optimization task is developed to obtain the optimal thermodynamic performance of the multi-mode cooling system. First, the numerical model is constructed using a well-validated evaporative cooler in the wet and wet-heating modes, as well as an air cooler in the dry mode. A well-suited experimental design is performed for generating an optimal set of samples by approximating the multivariate probability distributions of uncertain data. To reduce the computational burden, a customized parallel computing strategy is presented via parallelization of the task using the message-passing interface. Finally, an example illustrates that the time reduction is up to 93.5%, while the optimal exergy efficiency ratios are expected to be 37.0%, 17.3%, and 22.6% for the wet, dry, and wet-heating modes, respectively.

Experimental Investigation into the Heat and Mass Transfer in an Indirect Contact Closed Circuit Cooling Tower

The heat and mass transfer coefficients of the indirect contact closed circuit cooling tower, ICCCCT, were investigated experimentally. Different experiments were conducted involving the controlling parameters such as air velocity, spray water to air mass flow rate ratio, spray water flow rate, ambient air wet bulb temperature and the provided heat load to investigate their effects on the performance of the ICCCCT. Also the effect of using packing on the performance of the ICCCCT was investigated. It was noticed that these parameters affect the tower performance and the use of packing materials is a good approach to enhance the performance for different operational conditions. Correlations for mass and heat transfer coefficients are presented. The results showed a good agreement with other published works. Correlations are showed that the spray heat transfer coefficient is a function flow rates of spray water and air as well as spray water temperature while mass transfer coefficient is a function of spray water and air flow rates only.

SACTI model in prediction and assessment of large scale natural draft cooling tower environmental impact of nuclear power plant

Large Scale Natural Draft Cooling Tower has become a hot topic in China because it is an important part of the nuclear power plant, and its environmental impacts include shading, solar energy loss, water deposition and salt deposition. In China, there is no built large-scale natural draft cooling tower of nuclear power plant. Therefore, model prediction becomes an effective way to solve this problem. This paper introduces the basic principles and structure of SACTI (Seasonal and Annual Cooling Tower Impact) model. SACTI is a cooling tower assessment model developed by Argonne National Laboratory, USA. A comparative case study between China's Pengze Nuclear Power Plant and the US Amos Power Plant is also presented. Calculations were carried out for the Pengze and Amos power plants, and the results showed that the maximum value of salt deposition at the Pengze plant was about 166.5 kg/(km2-month) at a distance of 800 m from the cooling tower. The maximum value of salt deposition at the Amos plant was about 92.85 kg/(km2-month) at a distance of 600 m from the cooling tower. Conclusions show that the research work can provide a useful solution in future work, the simulation results of the SACTI model have a potential mean in the absence of monitoring data. This research provides a way to generate simulation data through SACTI program in the design process of nuclear power plant cooling tower, and designers can use these data to determine how the cooling tower will affect the natural environment and manage within an appropriate range to reduce the impact on the environment.

Analysis of the Effect of Packing Materials (Fills) and Flow Rate on the Range and Efficiency of a Forced Draft Evaporative Cooling Tower

In the present study, experimental investigation is carried out on two different kinds of packing materials (fills). PVC fills that are traditionally used in the industry are compared and analyzed against the cellulose-based paper fills. Different mass flow rates of air are used to study the effect of the flow rate of air on the forced draft cooling tower. The volume flow rate of water also varied, and the range of the cooling tower, along with efficiency, was analyzed. Along with these two parameters, the effect of inlet water temperature on the performance of the tower was studied. Cooling tower efficiency was plotted against different L/G ratios ranging from 0.95 to 7.67. Results showed that the type of packing has a significant impact on the cooling tower performance. Paper fills gave a maximum cooling tower efficiency and range equal to 93.12% and 16.5 °C, respectively. The optimal L/G ratio range of 0.96 to 1.44 was identified as the point at which the cooling tower demonstrated its highest performance. The effect of the mass flow rate of water on the performance of the tower was far greater compared to the volume flow rate of water and inlet water temperature. The paper fills are found to be most effective under current experimental conditions, and the same can be implemented in the industrial towers under a wide spectrum of inlet water temperatures, mass flow rates of air, and volume flow rates of water.

Sustainable production of green hydrogen, electricity, and desalinated water via a Hybrid Solar Chimney Power Plant (HSCPP) water-splitting process

This work presents a novel sustainable approach to producing desalinated water (Wdes), green hydrogen (GH2) and electrical energy (Eelc) using Hybrid Solar Chimney Power Plant (HSCPP) coupled with a water-splitting (WatSp) process. The HSCPP consists of a collector, absorber, chimney, bidirectional turbine outfitted with a seawater pool, and water electrolysis (Watelc) cell. The HSCPP harnesses solar energy to heat the air under the collector creating air movement within the structure, passing the bidirectional turbine, and producing Eelc. Sprinklers were fitted within the structure to operate the HSCPP as a cooling tower (CT) in the absence of solar radiation (Solirr). The Watelc cell directly uses the produced Eelc for the production of Hydrogen (PH2) and oxygen (PO2), while the condensed water at the chimney's inner walls was also collected as Wdes. Results revealed that the continuous operation of the HSCPP has an average annual Eelc of 633 ± 10 MWh that could be efficiently used to generate 21,653 kg of GRH2, 173,244 kg of O2 as well as 190,863 tons of Wdes. The overall efficiency of the HSCPP for the PH2 was found to be 18.5%, which is higher than Solar PV (max∼ 6%) and geothermal Rankine (max∼ 15%). These high efficiencies rank this technology as competitive with other renewable hydrogen production technologies. In conclusion, HSCPP has a promising future as a novel and sustainable solar tower technology to produce hydrogen.

State of art on FEM approach in inverse heat transfer problems for different materials

The present study investigates the utilisation of the Finite Element Method (FEM) in addressing Inverse Heat Transfer issues associated with diverse materials. The Finite Element Method (FEM) is a widely utilised methodology in engineering design that effectively tackles thermal problems and heat transfer. The versatility of this technology transcends the domain of engineering and has been found to have practical applications in various fields such as biomedical science, aerospace, and chemistry. The Finite Element Method (FEM) has demonstrated its proficiency in addressing inverse heat transfer problems that are linked to a variety of materials, each of which has unique characteristics. The following discourse proceeds to conduct a thorough analysis of the application of the Finite Element Method (FEM) in resolving inverse heat transfer predicaments with a view to achieving optimal results. The present paper expounds upon the inherent benefits and drawbacks associated with the utilisation of finite element techniques for the purpose of resolving inverse heat transfer problems. Furthermore, the present study examines the pragmatic implementation of the Finite Element Method (FEM) in addressing heat transfer issues in diverse fields, such as Boiler design, Heat exchanger design, Cooling tower design, and Nuclear reactor design. The paper offers tangible illustrations of how the FEM method can be utilised to tackle practical heat transfer difficulties by emphasising these particular applications. This paper provides a contribution to the comprehension of the effectiveness of the Finite Element Method when addressing inverse heat transfer problems. The aforementioned statement highlights the adaptability of this methodology in managing diverse substances with distinct characteristics and furnishes discernment into its benefits and drawbacks. Moreover, the article elucidates the multifarious implementations of the Finite Element Method (FEM) in the domain of thermal energy transfer, providing pragmatic exemplars of its efficacy in areas such as the design of boilers, heat exchangers, cooling towers, and nuclear reactors.

Modeling of Cooling Tower Operation with Consideration for the Chemical Work in the Steam–Air Mixture

Modeling of Cooling Tower Operation with Consideration for the Chemical Work in the Steam–Air Mixture

Mathematical Model and Experimental Data for Water Cooling in Counterflow Film Cooling Towers

Mathematical Model and Experimental Data for Water Cooling in Counterflow Film Cooling Towers

Effect of Black Carbon and Alumina Nanofluid on Thermal and Dynamic Efficiency in Upward Spraying Cooling Tower

In cooling water systems, cooling towers play a critical role in removing heat from the water. Cooling water systems are commonly used in industry to dispose the waste heat. An upward spray cooling water systems was especially designed and investigated in this work. The effect of two nanofluids (Al2O3/ water, black carbon /water) on velocity and temperature distributions along reverse spray cooling tower at various concentrations (0.02, 0.08, 0.1, 0.15, and 0.2 wt.%) were investigated, beside the effect of the inlet water temperature (35 ,40, and 45 ͦ C) and water to air flow ratio (L/G) of 0.5, 0.75, and 1. The best thermal performance was found when the working solution contained 0.1 wt.% for each of Al2O3 and black carbon nanoparticles, with a maximum drop in temperature drops (i, e. range) of (16 ͦ C) and (20 ͦ C), respectively. The temperature of the tower's outlet water was decreased as the inlet working fluid increased, and the thermal efficiency declined with the increasing of the L/G by about 5%. However, the drop in the outlet temperature caused by the nanofluid is more than that of pure water at every point by about 6 ͦ C.

Examining heat transfer of a buried pipe heat exchanger in arch tunnel lining with protection engineering

Cooling towers and internal reservoirs are two conventional heat transfer methods used in protection engineering. However, they have the drawbacks of easy exposure and limited capacity. Although the traditional ground source heat pump system can become a new heat transfer method, its high installation cost and space requirements are obstacles to the development of this technology. To address this problem, the heat exchange pipe of the ground source heat pump system being directly laid in the tunnel lining was proposed in this study. A heat transfer performance test platform for a lined buried pipe heat exchanger based on an arch tunnel was built, and the water velocity, wind velocity, and temperature of each measuring point were recorded under appropriate working conditions. The effects of the inlet water temperature, inlet water velocity, ventilation velocity, and initial soil temperature on the heat transfer performance were analyzed. The results have shown that the heat transfer performance of the tunnel reached its maximum when system operation commenced and then decreased gradually with time, and the rate of decrease gradually slowed. Along the radial direction of the tunnel, the shorter the distance to the buried heat exchanger, the greater the increase in soil temperature, and the shorter the time for the temperature to reach the peak value. As the distance increased, the temperature gradient gradually decreased. Along the circumferential direction of the tunnel, the lining temperature on the inlet side of the buried heat exchanger was higher than that on the outlet side. The temperature distribution on both sides of the symmetrical surface of the tunnel was not uniform, resulting in additional temperature stress in the horizontal direction. The time required for the heat transfer capacity of the tunnel to return to its initial value was approximately eight times that of the system. Compared with the ventilation and water velocities, the inlet water temperature and initial soil temperature had a greater impact on heat transfer. The heat-transfer law of an arch tunnel differs from that of a circular tunnel. There were some deviations when comparing the experimental data of the circular tunnel with those of the actual arch tunnel.

Assessment of Mechanical Draft Cooling Tower Thermal Emissions from Visual Images of Plumes

Using a one-dimensional code, we computed the power (enthalpy discharge rate) of a twelve-cell mechanical draft cooling tower (MDCT) using over two hundred visible condensed water vapor plume volume measurements derived from images, weather data, and tower operating conditions. The plume images were simultaneously captured by multiple stationary digital cameras surrounding the cooling tower. An analysis technique combining structure from motion (SfM), a neural-network-based image segmentation algorithm, and space carving was used to quantify the volumes. Afterwards, the power output was computed using novel techniques in the one-dimensional code that included cooling tower exhaust plume adjacency effects implemented with a modified version of the entrainment function, weather data averaged from eleven stations, and fan operations at the times when plume volumes were measured. The model was then compared with the averaged observed power output, and it validated well with an average error ranging from 6 to 12%, depending on the meteorological data used in the simulations. This methodology can possibly determine power plant fuel consumption rates by applying visible imagery.