Condensation Of Water Vapor Research Articles

A Chemical Methods Use of Reduce the Effects of Heavy Water Toxicity on Human and the Environment

Our current specialized scientific study includes the process of using chemical methods to remove or treat pollutants in heavy water represented by sewage water that is produced from multiple sources such as that coming out of homes, and other water such as water resulting from industrial waste, or other water resulting from different sources. The chemical oxidation method was used through the establishment of oxidation ponds of different sizes with a depth of (50-150 cm), mechanical rotation, exposure to sunlight and oxygen in the atmosphere, followed by the activation of aerobic bacteria that decompose organic matter. The most important factors and basic ingredients that were adopted in the treatment methods are solar energy and water vapor condensation, agitation and movement of the mixture mechanically, exposure to air, decomposition of organic materials, chemical reactions that take place under fixed relative conditions.

Water vapor condensation in porous media: Effects of fracture, porosity, and flow rate revealed by rapid 4D neutron imaging

Water vapor condensation in porous media: Effects of fracture, porosity, and flow rate revealed by rapid 4D neutron imaging

CFD Modelling and Simulation of the Thermal Management in a Polymer Electrolyte Membrane (PEM) Fuel Cell Stack

Polymer Electrolyte Membrane fuel cells are a promising technology for clean energy conversion due to their high efficiency and low emissions. However, one of the critical challenges in the operation of fuel cells is the effective management of temperature and humidity within the fuel cell stack. Uneven temperature distribution can cause uneven water vapor condensation, leading to performance inconsistencies among individual cells in the stack. This necessitates a comprehensive understanding and control of the thermal and humidity dynamics within the fuel cell stack to ensure optimal performance and longevity. In this study, with the use of COMSOL Multiphysics, a mathematical polymer exchange membrane fuel cell stack model is designed and is applied to assess the thermal control of a stack of polymer exchange membrane fuel cell made up of two end plates, five membranes electrode assembly, and five cells. The boundary conditions are established and the mathematical equations are numerically solved. The obtained results indicate that that the thermal and electrochemical performance within the fuel cell stack is significantly influenced by the distribution of cooling flow and gas reactants. Higher temperatures near the outlet highlight the importance of optimizing cooling strategies to prevent overheating and ensure uniform temperature distribution. Moreover, the observed variations in relative humidity suggest that water management is crucial for avoiding flooding, particularly in the first and last cells. This study also reveals the intricate relationship between temperature, humidity, and gas flow, which must be carefully balanced to prevent performance degradation. These insights suggest that optimizing the thermal and humidity management strategies is crucial for improving the durability and reliability of polymer exchange membrane fuel cell stacks.

Tunable diode laser absorption spectroscopy monitoring of the water vapor condensation process in the high-speed flow

Abstract In this work, non-invasive high-precision quantitative measurements of the water vapor condensation process have been carried out using tunable diode laser absorption spectroscopy at the sub-millisecond level. The high-speed condensation of water vapor is achieved by a self-designed rarefaction wave reflection system. Combined with different sizes of experimental cavities, the condensation process is realized at various time scales of sub-milliseconds (0.2–0.66 ms). The processes of temperature and water vapor content during the high-speed condensation are measured using the water vapor absorption spectra near 7168.437 cm−1 and 7185.597 cm−1. The experimental results show that the hypervelocity expansion flow field generated by the experimental system demonstrates good uniformity and reaches a cooling rate of 105 K·s−1, which has the same order as that of the supersonic nozzle. The condensation process is similar on different sub-millisecond timescales and the normalized temperature change curves are approximately the same. Moreover, the higher the water vapor content, the shorter the condensation time.

Robust and Ultra-Efficient Anti-/De-Icing Surface Engineered Through Photo-/Electrothermal Micro-Nanostructures With Switchable Solid-Liquid States.

Photothermal superhydrophobic surfaces present a promising energy-saving solution for anti-/de-icing, offering effective icing delay and photothermal de-icing capabilities. However, a significant challenge in their practical application is the mechanical interlocking of micro-nanostructures with ice formed from condensed water vapor, leading to meltwater retention and compromised functionality post-de-icing. Here, a robust photo-/electrothermal icephobic surface with dynamic phase-transition micro-nanostructures are demonstrated through laser microfabrication and surface engineering. The engineered surface exhibits ultra-efficient, long-term stable anti-/de-icing performance and excellent superhydrophobicity, demonstrating an icing delay of ≈ 1250 s, photothermal de-icing in 8 s, water contact angle of 165°, and sliding angle of 0.2°. Furthermore, the surface maintains efficient anti-/de-icing ability and water repellency after 400 linear abrasion cycles under 0.93MPa. Remarkably, under simulated natural icing conditions, where water vapor freezes within the micro-nanostructures causing mechanical interlocking, the surface remains entirely non-wetted after photo-/electrothermal de-icing, maintaining superhydrophobicity and effectiveness for continued anti-/de-icing. This exceptional performance is attributed to the designed phase-transition micro-nanostructures that liquefy during de-icing, significantly reducing interactions with water molecules, as quantitatively validated by molecular dynamics simulations. This work provides new perspectives and methodologies for designing and creating innovative, high-performance anti-/de-icing surfaces.

Research on a New Method of Water Recovery from Biogas Plant Digestate

Digestate is a product with valuable fertilizing properties, remaining after the anaerobic fermentation process. An essential feature of the substance in question is its high water content of up to 97%. To improve the fertilizer value of the digestate, it is necessary to dehydrate it to produce a concentrated product. This paper determined the possibility of dewatering the digestate using an innovative reactor design. The study, conducted on a laboratory scale, used digestate from a Polish biogas plant. The dewatering technique described in the paper is based on the evaporation and condensation of water vapor on the inner surface of the reactor dome. The condensate accumulated on the leach trough and was directed to a storage tank. During the weeks of testing, 11.5 kg of condensate was separated from the initial weight of the digestate (32 kg), with a dry weight of 6.11%. The resulting condensate from dehydration had an average pH value of 9.0 and an average ammonium nitrogen content of 2.07 g∙kg−1. The economic calculations made in the paper allowed for estimating the expected savings associated with the management of digestate in Poland. The research showed the proposed technology’s high potential for dewatering digestate under laboratory conditions.

The apparatus for atmospheric water harvesting in an arid climate - Prototype design and testing in laboratory conditions

The paper describes the development of a prototype system for water extraction from the air. The aim was to develop a device that allows one to autonomously obtain, without the need for external energy, an annual average of 100 L of water per day during extreme desert conditions. In this paper, a mathematical model simulating the operation of the unit for extracting water from the air in any climatic conditions is presented. Psychrometric calculations for different climatic conditions were carried out for two basic principles: condensation and sorption. The analyses confirmed that devices based on the condensation of water vapour from the air can only be used to a limited extent in extreme desert conditions. The average water production of a condensation-based system is only 20 l/day in Riyadh, with an air flow rate of 2000 m3/h. A unit with a desiccant wheel and an integrated heat pump was designed for water harvesting from the air. The prototype of the unit was tested in a climate chamber with the possibility of adjusting the climatic conditions and the presented mathematical model was experimentally verified. The final prototype designed for a nominal outdoor air flow rate of 2000 m3/h will produce 168 l of water per day under dry desert conditions (Riyadh) with continuous operation. The verification of the computational model allows one to determine the real water production and the required unit performance. An analyses of energy requirements and evaluation of levelized cost of water (LCOW) have been performed. Sorption unit has lower LCOW in target arid desert climate and electricity prices under 0.1 EUR/kWh compared to direct condensation technology.

Mechanism of ion migration from the substrate material into snow cover at the end of the cold period

Earlier, it was established that maximum mineralization of the contact layer of snow occurs in spring at the interface with substrates (soil or ice). This study analyzes the temperature and moisture conditions during this period at the interface of the contact layer of snow with substrates by examining frozen sand blocks saturated with a solution containing complex gold ions, or blocks filled with polystyrene containing ions of molybdenum, copper, etc. It is assumed that the migration of ions from the underlying substrate into the contact layer of snow cover in spring occurs along quasi-liquid films on the surface of snow crystals, the thickness of which exceeds the equilibrium one. Migration becomes noticeable when the temperature at the snow–substrate contact reaches −13 °С and above. The appearance of quasi-liquid films on the surface of snow particles under variable temperature and moisture conditions is possible due to the condensation of water vapor, which during the day, with general heating of the system, can enter the contact layer of snow both from above and below. With an increase in snow density in the spring, the mineralization of the near-contact layer of snow cover increases. At the same time, linear relationships were revealed between the content of substrate components migrating into the near-contact layer of snow and the gradient of water vapor density in it. The reliability of the approximation of these dependencies for the gold thiosulfate complex is 0.98; for copper ions – 0.52; for hydrogen ions – 0.88; for sodium ions – 0.69, for chloride anions – 0.89. The results of the study substantiate the increased efficiency of geochemical prospecting for mineral deposits using snow cover in the spring.

Comparison of theoretical methods for describing the heat transfer in vertical tube condensers under conditions corresponding to the condensation of flue gas from a biomass boiler

Abstract A theoretical and experimental study was conducted on water vapor condensation in a vertical tube condenser under conditions corresponding to the condensation of flue gas from biomass boiler where flue gas is considered as a mixture of water vapor and a high content of noncondensable gas (NCG). Four fundamental theoretical methods were identified to determine the heat transfer coefficient and condenser heat output - Empirical correlations, Heat and mass transfer analogy, Diffusion layer theory, Boundary layer theory. These methods were compared with respect to usability in the design of flue gas condensers in energy systems and experimentally verified. Experiments were carried out in a 1.5 m long vertical double-pipe condenser with a condensing gas flowing downward in an inner tube with a diameter of 25 mm. The mass concentration of NCG in a mixture with water vapor ranged from 11 to 86 vol.% and the inlet Reynolds number of the condensing gas ranged from 1936 to 14408, which corresponds with the conditions of condensing flue gas from biomass boilers. The boundary layer theory is very complex and impractical for the calculation of heat exchangers. Empirical correlations have a wide dispersion of the result, because they take into account only the basic parameters of the process. However, Heat and mass transfer analogy and Diffusion layer theory seem to be the most suitable for flue gas condensers since they capture the physical essence of the phenomena.

Quantitative and Qualitative Experimental Assessment of Water Vapor Condensation in Atmospheric Air Transonic Flows in Convergent–Divergent Nozzles

Atmospheric air, being also a moist gas, is present as a working medium in various areas of technology, including the areas of airframe aerodynamics and turbomachinery. Issues related to the condensation of water vapor contained in atmospheric air have been intensively studied analytically, experimentally and numerically since the 1950s. An effort is made in this paper to present new, unique and complementary results of the experimental testing of moist air expansion in the de Laval nozzle. The results of the measurements, apart from the static pressure distribution on the nozzle wall and the images obtained using the Schlieren technique, additionally contain information regarding the quantity and quality of the condensate formed due to spontaneous condensation at the transition from the subsonic to the supersonic flow in the nozzle. The liquid phase was identified using the light extinction method (LEM). The experiments were performed for three geometries of convergent–divergent nozzles with different expansion rates of 3000, 2500 and 2000 s−1. It is shown that as the expansion rate increases, the phenomenon of water vapor spontaneous condensation appears closer to the critical cross-section of the nozzle. A study was performed of the impact of the air relative humidity and pollution on the process of condensation of the water vapor contained in the air. As indicated by the results, both these parameters have a significant effect on the flow field and the pressure distribution in the nozzle. The results of the experimental analyses show that in the case of the atmospheric air flow, in addition to the pressure, temperature and velocity, other parameters must also be taken into account as boundary parameters for possible numerical analyses. Omitting information about the air humidity and pollution can lead to incorrect results in numerical simulations of transonic flows of atmospheric air. The presented results of the measurements of the moist air transonic flow field are original and fill the research gap in the field of experimental studies on the phenomenon of water vapor spontaneous condensation.

Probing Cold-to-temperate Exoplanetary Atmospheres: The Role of Water Condensation on Surface Identification with JWST

Understanding the surface temperature and interior structure of cold-to-temperate sub-Neptunes is critical for assessing their habitability, yet direct observations are challenging. In this study, we investigate the impact of water condensation on the atmospheric compositions of sub-Neptunes, focusing on the implications for James Webb Space Telescope (JWST) spectroscopic observations. By modeling the atmospheric photochemistry of two canonical sub-Neptunes, K2-18 b and LHS 1140 b, both with and without water condensation and with and without thick atmospheres, we demonstrate that water condensation can significantly affect the predicted atmospheric compositions. This effect is driven by oxygen depletion from the condensation of water vapor and primarily manifests as an increase in the C/O ratio within the photochemically active regions of the atmosphere. This change in composition particularly affects planets with thin H2-dominated atmospheres, leading to a transition in dominant nitrogen and carbon carriers from N2 and oxygen-rich species like CO/CO2 toward heavier hydrocarbons and nitriles. While our models do not fully account for the loss mechanisms of these higher-order species, such molecules can go on to form more refractory molecules or hazes. Planets with thin H2-rich atmospheres undergoing significant water condensation are thus likely to exhibit very hazy atmospheres. The relatively flat JWST spectra observed for LHS 1140 b could be consistent with such a scenario, suggesting a shallow surface with extensive water condensation or a high atmospheric C/O ratio. Conversely, the JWST observations of K2-18 b are better aligned with a volatile-rich mini-Neptune with a thick atmosphere.

Removal of moisture from air by cooling method

Moisture removal from air is a critical aspect of climate control in various industrial and residential applications. The cooling method, which relies on the condensation of water vapor by lowering air temperature below its dew point, is one of the most commonly used techniques for dehumidification. This study investigates the principles, effectiveness, and limitations of the cooling method in different environmental conditions. By examining the impact of factors such as ambient temperature, humidity levels, and cooling system design, this research aims to identify strategies for optimizing energy efficiency in dehumidification processes. Experimental results highlight the correlation between cooling temperature and condensation rates, emphasizing the need for advanced cooling technologies to reduce energy consumption. The findings contribute to the development of more sustainable and cost-effective dehumidification systems, offering valuable insights for enhancing HVAC performance and reducing environmental impact.

Experimental and Numerical Studies of Heat Transfer Through a Double-Glazed Window with Electric Heating of the Glass Surface

This paper presents experimental and theoretical studies of heat transfer through single- and double-glazed windows with electrical heating of the internal surfaces. Heating is achieved by applying a voltage to the low emissivity coating of the inner glass. A thermophysical model has been developed to simulate the heat transfer through these units, allowing us to determine their thermal characteristics. Experimental data are used to validate the numerical model. The resulting heat flux and temperature distributions on the external and internal surfaces of electrically heated double-glazed units are analysed. According to the results of experimental and numerical studies, it was found that the adopted electric heating scheme allows 83–85% of the heat to enter the room and 15–17% is removed to the outside. This makes it possible to increase the radiation component of the heat flow from the window to the room and improve the thermal comfort in the room. In general, this article shows that existing industrial windows with low-emissivity glass surface coating can be upgraded with simple and inexpensive modernisation, without compromising the main function of the window—efficient transmission of visible light—and create an additional (backup) heating device that can work effectively together with the existing heating system in the event of a sudden cold snap at low temperatures (below −20 °C), to prevent condensation of water vapour in the windows, and to prevent condensation on the surface of the window facade wall. Formally, a back-up (emergency) heating system is created in the room, which contributes to the energy sustainability of the building and therefore to energy security in general.

Iron doping enhances the bind stability of transpiration water to Zr-based MOFs packaging

The metabolic processes of fruits induce water vapor condensation in packaging, creating a high-humidity microenvironment that exacerbates the proliferation of microorganisms and causes food spoilage. Therefore, a Fe/Zr bimetallic organic framework (Fe-MOF-801) packaging (i.e., FeMGCF) with high binding stability to transpiration water was prepared based on transition metal Fe doping strategy, and the mechanism of its enhanced binding stability towards transpiration water was investigated. The results indicate that Fe enhances the interaction between MOFs and H2O by promoting the charge depletion at the O sites coordinated with Zr, thereby increasing the aggregation tendency of H2O in the T1 and T2 cavities (characterized by strong hydrogen bonding) of Fe-MOF-801, which increased the binding energy of MOFs to H2O by 29.6 %. Accordingly, the application of FeMGCF packaging extended the shelf life of tomatoes by 6 days and delayed the degradation of lycopene and anthocyanins during postharvest tomato preservation.

Эффект интенсивного окисления сероводорода дымовых газов содорегенерационного котла при производстве целлюлозы

Despite the transition to the Swedish technology for regenerating black liquor from pulp production plants, even in those regions of Russia where the standard daily average levels of hydrogen sulfide and methyl mercaptan in the air of populated areas have been achieved, a number of problems remain with emissions of reduced sulfur. In many cities, onetime concentrations of reduced sulfur, especially at night, may exceed the permissible ones. In addition to flue gas emissions from soda recovery boilers, there are other, less intensive sources of harmful emissions in the cooking, evaporation and wood-chemical workshops, in the causticization and lime regeneration workshops, there are emissions from unorganized sources and from the open surface of wastewater treatment facilities. The population living near such plants feels the unpleasant odor of methyl mercaptan. This study has aimed to develop a new technology for reducing gas emissions of reduced sulfur into the environment, applicaple for different sources. The results of testing an industrial installation for purification of gas emissions from a soda recovery boiler in a scrubber with nozzle irrigation have been presented. Based on the measurements of the technological parameters of the operation mode of the gas purification plant and the determination of the composition of the irrigation solution, the analysis of the results obtained has been performed. During the tests, a high degree of hydrogen sulfide capture at a low pH value has been achieved. It has been established that hydrogen sulfide has been captured as a result of its oxidation before entering the irrigation solution in fine droplets of condensate formed on micron-sized particles of sulfate and sodium carbonate. The results of this study have been compared with the results of the studies conducted by Stanford University and the P.P. Shirshov Institute of Oceanology of the Russian Academy of Sciences. The possibility of hydrogen peroxide formation under our test conditions in the surface layer of fine droplets formed during the condensation of water vapour on dust particles has been analyzed. The suposed cause of the obtained effect has been determined to be the thermomechanical deformation of the surface layer of the droplets.

Analysis of noctilucent clouds’ fields according to ground-based network and airborne photography data

The article analyzes the fields of noctilucent clouds over the territory of the Russian Federation, recorded by a ground-based network of cameras using also aircraft photography, over the two nights in June 2021. It is demonstrated that aircraft photography can significantly improve the coverage of the territory of noctilucent clouds’ probable appearance. The detected noctilucent cloud fields are compared with model regions of water vapor condensation derived from satellite measurements of temperature and water vapor mixing ratio. Practical steps are proposed for the development of aircraft observations of noctilucent clouds.

Relevance of Bacteria in Causing Rain and Snow.

The Earth's climate is influenced by both natural phenomena (solar fluctuations, oceanic patterns, volcanic eruptions, and tectonic movements) and human activities (deforestation, CO and CO2 emissions, and desertification), all of which contribute to ongoing climate change and the resulting global warming. However, human actions are a major factor in exacerbating global warming and amplifying its adverse impacts worldwide. . With rising temperatures, water evaporation from water bodies and soils intensifies, leading to heightened water scarcity, particularly in drought-prone regions. This scarcity compounds rainfall deficits, posing significant challenges. Precipitation, essential for the biosphere's hydrological cycle, replenishes much of the world's freshwater. It occurs when condensed water vapor in the atmosphere falls back to Earth as rain, drizzle, sleet, graupel, hail, or snow due to gravity. Literature highlights the indispensable role of bacterial populations in this process, termed bio-precipitation. This phenomenon begins with bacterial colonization on plant surfaces, with colonies subsequently dispersed into the atmosphere by winds, triggering ice crystal formation. Through their ice nucleating property, these bacteria facilitate the growth of larger ice crystals, which eventually melt and precipitate as rain or snow. This mechanism aids in nutrient transfer from clouds to soil or vegetation. Pseudomonas syringae stands out as the most notable microorganism exhibiting this ice-nucleation property, serving as the primary source of ice nucleators driving bio-precipitation. Despite limited literature on "rain and snow-causing bacteria," this review comprehensively explores the conceptual background of bio-precipitation, the involved bioprocesses, and the critical role of bacteria like P. syringae, offering insights into future research directions.

Separation of multicomponent gas mixtures

In the production of granular organo-mineral fertilizers using the fluidization technique by dehydrating heterogeneous liquids, as an energy-efficient technology, there is a need to purify the spent coolant containing solid particles, dust and a significant amount of water vapor. Solid particles up to 20 microns in size are effectively captured in cyclone devices. To further capture water vapor and fine solid particles, a scrubber is used with an additional circulation circuit involving an additional bone of water, which, upon reaching a concentration of more than 20%, is discharged back to the granulation stage. This leads to an increase in energy consumption for production in general. Condensation of vapors in a dispersion containing 5-7% (w/w) moisture in the form of water vapor at the second stage of purification will increase the level of environmental safety in production. To select an innovative method of separation of multicomponent gas dispersions accompanied by a change in the aggregate state and a rational design of the apparatus, a review of scientific articles and developments such as systematization of existing methods was carried out. Such an approach makes it possible to choose the optimal solution for the separation of gas-dust and gas-liquid flows in the conditions of the existence of a large number of types of equipment design and the level of their innovation. In addition to the rational design of the devices, great attention was also paid to the issues of energy efficiency, resource saving and ensuring the state of environmental safety at production facilities in the conducted research. Based on the results of the analysis, it is proposed to use a scheme of consecutively installed cyclones CN-11 and SK‑CN-33. It is proposed to use the ЦН-11 cyclone for the preliminary capture of highly dispersed dust, and the SK-CN‑33 for condensation and capture of water vapor and solids not caught in the previous cyclone particles.

Overcoming bubble formation in polydimethylsiloxane-made PCR chips: mechanism and elimination with a high-pressure liquid seal

The thermal expansion of gas and the air permeability of polydimethylsiloxane (PDMS) were previously thought to be the main causes of bubbles and water loss during polymerase chain reaction (PCR), resulting in a very complex chip design and operation. Here, by calculating and characterizing bubble formation, we discovered that water vapor is the main cause of bubbling. During PCR, heat increases the volume of the bubble by a factor of only ~0.2 in the absence of water vapor but by a factor of ~6.4 in the presence of water vapor. In addition, the phenomenon of “respiration” due to the repeated evaporation and condensation of water vapor accelerates the expansion of bubbles and the loss of water. A water seal above 109 kPa can effectively prevent bubbles in a bare PDMS chip with a simple structure, which is significant for the wide application of PDMS chips.

Integrated solar dryer and distillation system with PCM and injection, powered by PVT panels and solar concentrator

This research introduces a novel hybrid system integrating solar drying, solar distillation, and photovoltaic thermal panels, aimed at drying agricultural products, producing clean drinking water, and conserving energy. The system enhances the drying air temperature using thermal energy storage materials and a solar dish concentrator connected to a hot water storage tank, ensuring continuous operation even after sunset. The solar distiller, equipped with energy storage materials and an air injection system, is integrated with an external condenser to condense water vapor before expulsion, thereby increasing freshwater productivity. The results revealed that the developed system achieved an accumulative freshwater productivity of 87.1 L per day. The rates of water removal from dried potato slices ranged from 0.18 to 0.91 kg/h between 8:00 am and 10:00 pm. Additionally, the system achieved a gain output ratio of 1.38, indicating a significant improvement in energy efficiency. This innovative system offers practical solutions to address energy and freshwater scarcity, especially in remote regions of the Middle East and North Africa (MENA) region, which are characterized by high solar irradiance. The implementation of such hybrid systems could contribute to sustainable development by reducing reliance on conventional energy sources and mitigating environmental pollution.