Fogging System Research Articles

Spatial Variation of Microclimatic Parameters Inside a Polyhouse with Fog Cooling System

The importance of protected cultivation is increasing day by day due to its capability of producing crop all round the year and increase in the crop productivity. This advantage of protected cultivation can be efficiently achieved by adapting the polyhouse cultivation. To obtain the maximum crop productivity inside a polyhouse, it is necessary to understand the variability of microclimate inside it. The present study aims to understand the spatial variability of microclimate inside a naturally ventilated polyhouse installed with fog cooling system during summer season. The main aim of the study is to understand the effect of fogging system in spatial variability of microclimate. For the study, the data of microclimatic parameters were collected daily from April to June at four different time intervals 8.30 AM, 12.30 PM, 4.30 PM and 8.30 PM. The data recorded was then analyzed in Golden Surfer Software to generate contour plots of weekly averages of microclimate parameters. The analysis revealed that the temperature and relative humidity varied across the polyhouse depending upon the wind velocity and its distribution pattern. The light intensity varied based upon the orientation of polyhouse and the position of sun. Carbon dioxide concentration varied based on temperature, light intensity, crop transpiration and respiration. It can be concluded that, inside a naturally ventilated polyhouse, the microclimate varied both spatially and temporally with fogging system also due to wind effect. Thus, having accurate understanding of the microclimate inside a polyhouse helps to maintain optimal conditions for plant growth and thus improve crop yield and productivity.

Enhanced water production in pyramid solar stills: Utilizing suspended trays, fogging system, and forced condensation

This work investigated how to improve the thermal efficiency of pyramid distiller (PSD). A modified PSD (MPSD) was constructed with suspended trays (4-cm width) on three vertical walls. The performance of the MPSD with and without a fogging system was evaluated. Additionally, the MPSD was integrated with an external condensation unit using a withdrawing fan operating at various speeds (1, 1.5, 2, 2.5, 3, & 3.5 rpm). The MPSD with suspended trays exhibited a significant improvement, achieving a 35 % increase in distillate yield compared to the PSD. The MPSD with a fogging system demonstrated a 160 % yield increase. The highest thermal performance for the MPSD with trays, fogger, and external condenser was attained at a fan speed of 2 rpm. At this setting, the MPSD's productivity increased by 194 % with a thermal efficiency of 62.4 %. Notably, the cost of water production decreased from 0.24$/L for the PSD to 0.18$/L for the MPSD. These findings suggest that the MPSD with suspended trays, fogging system, and external condenser offers a promising approach to enhance both the yield and efficiency of solar desalination.

A practical solution for multivariable control of temperature and humidity in greenhouses

This paper presents a simple and effective control solution to regulate temperature and humidity inside a greenhouse, which are the main climatic variables affecting crop growth and health. A multivariable control strategy with inverted decoupling is proposed in two schemes. The nighttime control scheme uses heating and dehumidification, and the daytime control scheme uses natural ventilation, dehumidification, and humidification. A system identification methodology is used to obtain low-order linear models from data measured in a greenhouse. This simplifies the design of proportional–integral (PI) controllers and allows the use of well-known control techniques. For instance, anti-windup is used to deal with the saturation of the actuators and for a bumpless transfer mechanism to switch between the nighttime and the daytime control schemes. Setpoint weighting is used for the humidity controllers to attenuate undesired effects on the temperature control loop when the humidity setpoint is changed. Furthermore, split range control is used for the first time to control humidity by combining a heat-pump dehumidifier and a fogging system. The control solution presented in this work allows the integral absolute error to be reduced, on average, by 88.5% for the interactions affecting the temperature control loop, and by 85.6% for the humidity control loop, compared to decentralized PI control. The control schemes have been tested in simulation with real disturbance data from a Mediterranean greenhouse and in preliminary form in a real facility to conclude that the proposed multivariable control strategy could be effective in decoupling the temperature and the humidity control loops.

Technical and Economical Evaluation of the enhancement of gas turbine power plant using air cooling fogging system

Technical and Economical Evaluation of the enhancement of gas turbine power plant using air cooling fogging system

Water-energy nexus in the combined cycle power plant using energy, exergy, economic and environmental analyses

The growing demand for water and energy and the limitation on their resources necessitate comprehensive studies on the water-energy nexus from different aspects in large industries, especially power plants. In the present study, the water-energy nexus has been analyzed using energy, exergy, economic, and environmental analyses for the retrofit scenarios in a combined cycle power plant. The injection of boiler blow-down into the condenser will save 47809.5 m3 of make-up water and 1.115 million m3 of natural gas per year. Replacing the Maisotsenko evaporative cooler with the fogging system increases the revenue index and the water consumption index by 2.7%. The raw water is replaced with high-quality water. The output power of the combined cycle power plant is reduced by 2.1 MW (0.83%) due to the steam injection from the heat recovery boiler into the combustion chamber of the gas unit, while its exergy degradation rate is reduced by 8.5 MW (2.42%). Also, the efficiency of the first and second laws have been decreased by 0.49% and 0.4%, respectively. The results show that the recovery of boiler blow-down for condenser or steam injection into the combustion chamber of the gas unit from heat recovery of the boiler reduces water consumption and exergy destruction simultaneously. Using Maisotsenko cycle and steam injection into the combustion chamber of the gas unit from the heat recovery of boiler reduces the exergy destruction and NOx emissions. The present study provides useful insights to quantify the water-energy nexus for decision-makers in the industry to reach proper decisions according to the opportunities and limitations.

Effects of Fogging System and Nitric Oxide on Growth and Yield of 'Naomi' Mango Trees Exposed to Frost Stress.

In years with unfavorable weather, winter frost during the blossoming season can play a significant role in reducing fruit yield and impacting the profitability of cultivation. The mango Naomi cultivar Mangifera indica L. has a low canopy that is severely affected by the effects of frost stress. As a result of the canopy being exposed to physiological problems, vegetative development is significantly inhibited. The current investigation aimed to study the influence of spraying nitric oxide and fogging spray systems on Naomi mango trees grafted on 'Succary' rootstock under frost stress conditions. The treatments were as follows: nitric oxide (NO) 50 and 100 μM, fogging spray system, and control. In comparison to the control, the use of nitric oxide and a fogging system significantly improved the leaf area, photosynthesis pigments of the leaf, the membrane stability index, yield, and physical and chemical characteristics of the Naomi mango cultivar. For instance, the application of 50 μM NO, 100 μM NO, and the fogging spray system resulted in an increase in yield by 41.32, 106.12, and 121.43% during the 2020 season, and by 39.37, 101.30, and 124.68% during the 2021 season compared to the control, respectively. The fogging spray system and highest level of NO decreased electrolyte leakage, proline content, total phenolic content, catalase (CAT), peroxidases (POX), and polyphenol oxidase (PPO) enzyme activities in leaves. Furthermore, the number of damaged leaves per shoot was significantly reduced after the application of fogging spray systems and nitric oxide in comparison to the control. Regarding vegetative growth, our results indicated that the fogging spray system and spraying nitric oxide at 100 μM enhanced the leaf surface area compared to the control and other treatments. A similar trend was noticed regarding yield and fruit quality, whereas the best values were obtained when the fogging spray system using nitric oxide was sprayed at a concentration of 100 μM. The application of fogging spray systems and nitric oxide can improve the production and fruit quality of Naomi mango trees by reducing the effects of adverse frost stress conditions.

149 Case Study: The Impact of a Fogging System on Dairy Cow Comfort in Cows Housed in a Barn with Tunnel Ventilation and an Automatic Milking System

Abstract Fogging systems control microclimatic parameters of barns to provide immediate cooling to dairy cows during heat stress conditions. However, the benefits of implementing a fogging system to cow comfort behaviors have not been thoroughly investigated in lactating cows. Therefore, the objective of this case study was to evaluate cow comfort behaviors and milk productivity in cows managed in a tunnel-ventilated barn in a commercial dairy farm that uses an automatic milk system. Sixty Holstein lactating dairy cows (45-90 days in milk; DIM) were monitored and housed in group pens (6 pens; n = 10 cows/pen). Four weeks before the fogging system installation, cows had pedometers (IceQube, IceRobotics, Inc., United Kingdom) and SCR rumination collars (SCR by Allflex; Israel) placed for continuous daily activity and rumination levels monitoring, respectively. Productivity information was acquired using automatic robotic milking technology (Lely Astronaut A5; Iowa, United States), and all variables were measured until four weeks after fogger system installation. Activity behavior (lying duration, daily step count, and number of transitions) and productivity (daily milk yield and milk speed) were evaluated before (PRE; 20-day pre-installation period), during (DURING; 2-day period), and after fogger installation (POST; 35-day post-installation period). Data were analyzed using PROC GLM in SAS 9.4 with cow as the experimental unit and temperature-humidity index (THI) included in the model as a covariate. Overall, cows spent more time lying (P < 0.01) in the POST period versus PRE and DURING. Cows performed fewer daily transitions between lying and standing (P < 0.01) in the POST versus PRE period, but no differences were detected (P = 0.67) among the step counts observed PRE, DURING, and POST fogger installation. Average milk speed and average milk yield were decreased (P < 0.01) in the POST period compared with the PRE and DURING periods. Temperature-humidity index significantly influenced (P < 0.01) lying time but did not have an effect on any other variables measured. In summary, installation of a fogger system in a commercial tunnel-ventilated barn improved cow comfort behaviors in lactating cows managed with an automated robotic milking system but did not offer immediate production performance benefits.

Evaluation of Gas Turbine Performance in Power Plant with High-Pressure Fogging System

Evaluation of Gas Turbine Performance in Power Plant with High-Pressure Fogging System

Analysis Of The Cause Of The Imperfect Process Of Fogging The Injector Of The Main Engine On The Ship KMP. Trimas Laila

One of the components contained in the main motor, which affects the combustion system is the injector. The smog of fuel into the combustion chamber is determined by whether or not the condition of the nozzle on the injector is good. If the middle nozzle is in a state of constraint, the nozzle cannot atomize the fuel optimally. If that happens, the combustion process will also be disrupted and will affect the power of the engine. The method carried out at this KKW uses data collection techniques by direct observation during maintenance and direct interviews from people who know on the ship, with the aim of knowing the cause of the imperfection of the injector fogging process on the main engine on the ship, it will affect the injection and fogging system on the ship. ship so that it can be known what factors are the cause of the problem. Based on the results of research that has been carried out on the KMP. Trimas Laila, it can be concluded that what affects the imperfection of the fogging process on the injector is the clogged nozzle hole and the dripping of fuel at the tip of the nozzle. from this it can result in the engine not reaching maximum speed and irregular exhaust gas which initially reached 360oc to 440oc, after treatment the exhaust gas temperature returned to normal to 360 oc.

Evaluation of Germplasm for Breeding High-temperature Tolerant Paprika

Other SectionsAbstractPaprika (Capsicum annuum) cannot grow or set fruit in temperatures that are higher than the optimal level. This study assesses the characteristics of 52 paprika accessions introduced from the agrobiodiversity center and the world vegetable center during a high temperature period in order to develop heat tolerant lines. As a result of controlling the temperature in two greenhouses by side ventilation and fogging system, the average daily temperature of the high temperature regime was 34.3℃, which was 2.4℃ higher than that of the normal temperature regime. Plant height, stem diameter, fruit set, fruit weight, fruit shape, pericarp thickness, soluble sugar content, yield, and marketable fruit development rate were all investigated as vegetative and reproductive growth-related parameters. Plant height, fruit weight, pericarp thickness, and yield were all reduced during high temperature treatment. Six germplasm lines (T12, T15, T26, T29, T32, and T36) were selected as high-temperature tolerant lines based on these parameters. The selected lines will be used to breed heat-tolerant cultivars as well as crossbreeding for genetic analysis.Keywords : evaluation, germplasm, heat tolerance, high-temperature, paprika

Study on the Minimum Fire-Extinguishing Concentration of Several Commonly Used Extinguishing Agents to Suppress Pyrolysis Gas of Red Pine Wood.

The suppression of forest wood burning has been one of the important research directions in the field of solid combustible fire safety. The process of forest wood flame propagation is a coupled process of solid-phase pyrolysis and gas-phase combustion chemical reactions; therefore, as long as the solid-phase pyrolysis or gas-phase combustion can be suppressed, the forest wood flame propagation can be suppressed and an important contribution can be made to the subsequent suppression of forest wood fires. Previous studies have focused on the inhibition of solid-phase pyrolysis of forest wood, so this paper examines the effectiveness of several common fire suppressants for suppressing forest wood gas-phase flames, starting with the inhibition of forest wood gas-phase combustion. In this paper, for the convenience of the study, we narrowed the scope of the research object to the previous research ideas for gas fires, established a simplified small-scale flame model for forest wood fire suppression, took red pine wood as the research object, analyzed the pyrolysis gas components after high-temperature pyrolysis, and constructed a Cup burner suitable for N2, CO2, fine water mist, and NH4H2PO4 powder to extinguish the pyrolysis gas flame of red pine wood, respectively. The experimental system, together with the 9306 fogging system and the improved powder delivery control system, shows the process of extinguishing fuel flames such as red pine pyrolysis gas at 350, 450, and 550 °C with various types of fire-extinguishing agents on this device. It was found that the flame morphology was related to the composition of the gas and the type of extinguishing agent. At the same time, NH4H2PO4 powder appeared to burn above the cup mouth when pyrolysis gas interacted with it at 450 °C, but this phenomenon did not occur when other extinguishing agents interacted with it and only appeared when pyrolysis gas interacted with it at 450 °C, so it was judged that this phenomenon was related to the CO2 content of the gas component and the type of extinguishing agent. The study found that the four extinguishing agents extinguish red pine pyrolysis gas flame MEC value. There's a big difference. The worst performance is N2. Compared with N2 suppression of red pine pyrolysis gas flame, CO2 suppression effectiveness is 60% higher, but compared to the suppression effectiveness of fine water mist and far away, the suppression effectiveness of fine water mist is much higher than the suppression effectiveness of CO2. However, the difference in effectiveness between fine water mist and NH4H2PO4 powder is almost double. In summary, in the suppression of red pine gas-phase flame, four kinds of fire-extinguishing agents are ranked as follows: N2 < CO2 < fine water mist < NH4H2PO4 powder. Finally, the suppression mechanism of each type of extinguishing agent was analyzed. The study of this paper can provide some data to support the extinguishing of open fires in forest fires or suppressing the rate of forest fire spread.

Modifying Walk-In Tunnels through Solar Energy, Fogging, and Evaporative Cooling to Mitigate Heat Stress on Tomato

Global warming is by far the most significant issue caused by climate change. Over the past few decades, heat stress has intensified into a serious issue that has a negative impact on crop production. Hence, it is crucial to modify cultivation systems to cope with this kind of stress, particularly in arid dry regions. In comparison to open-field cultivation, tomato production under protected cultivation techniques in walk-in tunnels that are suited for different farmers’ financial abilities was evaluated during the late summer season. The studied tunnels included a shaded net tunnel with natural ventilation, net tunnel with a fogging system and plastic tunnel with evaporative cooling (wet pad and fans). For the operation of fogging and evaporative cooling systems, solar energy was used as a sustainable, eco-friendly energy source. The results indicated that the solar energy system successfully operated the studied cooling systems. All studied protective cultivation techniques mitigated heat stress on tomato plant and improved the microclimate under walk-in tunnels. Moreover, evaporative cooling and fogging systems significantly increased plant leaf area, cell membrane efficiency and the contents of chlorophyll, relative water and proline compared to the net tunnel with natural ventilation. Furthermore, a marked reduction in physiological disorders was noticed. Improved physiological and biochemical parameters and limited physiological diseases led to higher fruit set, marketable fruit yield and total productivity. The percentage of marketable fruit yield increased by around 31.5% with an evaporative cooling system, 28.8% with a fogging system and 17% with a shaded net tunnel with no positive cooling as compared to an open field. However, the plants grown in open-field cultivation without protection significantly deteriorated from heat stress and had a high incidence of physiological disorders. The most incident physiological disorders were blossom-end rot, cracking, internal white tissues, sunscald, puffiness, blotchy ripening, cat face and exserted stigma. It is recommended to use a solar energy system to modify microclimate conditions through fogging or evaporative cooling under walk-in tunnels to ameliorate heat stress on grown tomato in the late summer season for higher fruit yield and fewer physiological disorders.

Application of Biodiesel in Fogging System with Azadirachta Indica Oil as Insecticide towards Mosquito and Larvae

The study highlighted the application of biodiesel as a carrier fuel with azadirachta indica oil as insecticide in thermal fogging system towards adult mosquitoes and mosquito larvae. The open fogging test is conducted indoor inside a visible container (dimension: 50 cm x 50 cm x 50 cm) with different dilution ratio of azadirachta indica oil and biodiesel to determine the ideal ratio for the formulation to give effects towards mosquitoes and mosquito larvae effectively. Spread-ability test is also conducted to examine the effectiveness of the insecticide-carrier solution in a real-life simulation. The biodiesel used was produced through the hydrotalcite catalyzed transesterification derived from palm oil. The adulticidal and larvicidal activity of biodiesel and azadirachta indica oil as fuel-insecticide is evaluated through dilution ratio of 9:1, 1:1 and 3:7. The fuel-insecticide solution is dispersed in the visible tank by heating it to produce fog. From the tests conducted, the most ideal dilution ratio effect is 1:1 towards both adult mosquito and mosquito larvae. The ratio indicated the shortest time to achieve 100% mortality rate in adult mosquitoes (20 minutes). While in spread-ability test, 55 minutes was taken to achieve total mortality. In larvicidal potential, the ratio of 1:1 showed the highest larvae deceased which is 2 out of 3 larvae for both open and spread-ability test.

Hatay İli Hassa İlçesinde Bulunan Bazı Yabani (Delice) Zeytin (Olea europaea L. subps. oleaster) Genotiplerinin Çelikle Köklenebilme Durumlarının Araştırılması

Seleksiyon neticesinde elde edilmiş bazı yabani (delice) zeytin genotiplerinin köklenme performanslarının araştırılması amacıyla hazırlanan bu çalışmada, Kasım 2020 - Mart 2022 tarihleri arasında Hatay ili Hassa ilçesinde yoğun olarak bulunan yabani zeytin popülâsyonları içerisinden selekte edilen 133 genotip materyal olarak kullanılmıştır. Çalışma Hatay Zeytincilik Araştırma Enstitüsü Müdürlüğü Hassa İstasyonu İşletmesi’nde yürütülmüştür. Çalışmada köklenme materyali olarak perlit kullanılmıştır. Ortalama 25 cm ebatlarında hazırlanan çeliklerin 3 cm’lik dip kısımları 4000 ppm dozunda hazırlanmış indol butirik asit (IBA) solüsyonuna 5 sn süreyle daldırılmıştır. 25oC’ye ayarlanmış alttan ısıtmalı, sisleme üniteli, yarı otomatik seraya dikimleri gerçekleştirilmiştir. Bu şekilde 90 günü tamamlayan genotiplere ait çelikler sökülerek köklenme oranı, kök sayısı, kök uzunlukları tespit edilmiştir. Çalışma neticesinde, tüm veriler ışığında anaç olma potansiyeli yüksek olan ilk 5 anaç adayı; 917 puan ile 31.8.2.39 No’lu genotip, 860 puan ile 31.8.16.11 No’lu genotip, 798 puan ile 31.8.2.36 No’lu genotip, 797 puan ile 31.8.2.34 No’lu genotip ve 772 puan ile 31.8.16.16 No’lu genotip olmuştur.

Development of Decision Support System (DSS) for Greenhouse Ventilation and Cooling Control

The confined heat created by the sunlight and ambient temperature is one of the obstacles to greenhouses in the tropics. A conservatory in tropical regions thus requires a proper ventilation and cooling system to provide an ideal greenhouse temperature to support crop production. The main objective of this study is to develop a Decision Support System (DSS) for optimum greenhouse ventilation and cooling control. An equation model to predict the temperature inside was developed by considering heat generation and heat loss inside the greenhouse. The accuracy of the equation model was validated with secondary data from the on-field greenhouse by statistical evaluation metrics. The statistical evaluation proved that the equation model is good with 2.11°C of Root Mean Square Error (RMSE), 6.22% of Percent BIAS (PBIAS) and 0.94 of Nash-Sutcliffe efficiency (NSE) value. A DSS using Microsoft Excel with Visual Basic for Applications (VBA) is developed based on the equation model to provide the ventilation and cooling system information. Input required for the DSS is a climatic condition, dimension and covering greenhouse material. The output of the DSS is the temperature inside the greenhouse, natural ventilation design, forced ventilation, active cooling system design using an evaporative pad and fan, and fogging system. The DSS can be used as an approach for ventilation and cooling design recommendation for the optimum temperature inside the greenhouse.

Performance analysis of selective exhaust gas recirculation integrated with fogging cooling system for gas turbine power plants

Selective exhaust gas recirculation (S-EGR) is a proposed alternative for enhancing the CO2 capture units applied in power plants. Most previous studies focused on the correlation between S-EGR and CO2 capture unit efficiency. Nevertheless, the S-EGR system without pre-cooling considerably influences the gas turbine output power due to its relatively high temperature. Hence this study aims to investigate the influence of the integration of fogging cooling systems with S-EGR on gas turbine performance. This combination could reduce the adverse effects of the S-EGR system in power plants as well as increase the effectiveness of the fogging cooling system in hot, humid regions. A three-dimensional Euler–Lagrange CFD model is employed to simulate the mutual effect between S-EGR and fogging cooling systems under different operation conditions. The impact of output condition from combined fogging and S-EGR system (cooled CO2 enriched air) on the gas turbine performance is then investigated. Results illustrate that applying the fogging cooling approach after mixing the inlet air and S-EGR reduces the moisture content of the inlet air and augments the cooling capacity of the fogging system. When the CO2-enriched stream is pre-cooled to the same ambient temperature, the fogging system outlet temperature drops more, especially at high S-EGR ratios. Applying the S-EGR system could increase the inlet mixture density (CO2-enriched air) by about 12% at an S-EGR ratio of 35%, which is increased to 18% after incorporating the fogging cooling system. Regarding gas turbine performance, using CO2-enriched air without pre-cooling leads to a significant deterioration in performance, notably at high S-EGR ratios. On the other hand, the amalgamation of S-EGR with fogging cooling could boost gas turbine output power from 11.7 to 19.2%, with an efficiency gain of half a percentage point.

Sustainable cooling strategies to minimize water consumption in a greenhouse in a hot arid region

Evaporative cooling systems are the currently used technology for providing cooling to greenhouses in arid regions where typically the greenhouse is ventilated. However, they consume a large quantity of water to cool the air. A closed greenhouse is proposed that uses earth-air heat exchangers (EAHE) and fogging to control the interior temperature and relative humidity in a water-efficient manner. A numerical model has been developed for the greenhouse and EAHE, and have been validated against experimental data collected from literature. Simulations are performed to compare the proposed closed greenhouse performance against the fan-pad system in a ventilated greenhouse in maintaining a suitable temperature and humidity, and to estimate the water usages. The EAHE reduced the water consumed by the fogging system by 50 % and the maximum interior temperature from 50 °C to 35 °C. The temperature reduction was found comparable to a fan-pad system with a ventilation rate of 20 air changes per hour, however, with a more stable relative humidity at approximately 75 %. Furthermore, water used for cooling was lower by one tenth of that of the fan-pad system, reducing it from 53 litre/day to 5 litre/day.

Mitigating the Adverse Effects of Semi-Arid Climate on Capsicum Cultivation by Using the Retractable Roof Production System.

Capsicum (Capsicum annuum L.) belongs to the Solanaceae family and is an economically important vegetable crop. However, the crop is very sensitive to adverse weather conditions such as high temperatures and excessive sunlight, which cause flower and young fruit to drop and sunscald to mature fruits. Using protected cultivation such as shade covers or net houses is a feasible agronomic approach to protect the crop from high light intensity, which increases plant growth, reduces fruit damage, and increases marketable fruit yield and quality. Low-cost protected cropping options such as fixed-roof net houses have proved cost-effective and suitable for fruiting vegetable production in semi-arid climatic regions. However, this structure type is unable to protect the crops from rainfall, is prone to cyclone damage and is inflexible to accommodate various vegetable crops which have different requirements for healthy and productive growth. This study was conducted in Carnarvon, which has semi-arid climatic conditions and is a key horticultural district of Western Australia, to compare the Retractable Roof Production System (RRPS) and open field (OF) conditions in the production of capsicum. The data showed that the RRPS modified the internal light, temperature and humidity in favour of the capsicum crop. The RRPS-grown capsicum had higher plant height and lower canopy temperature on hot days than those in the OF. The mean marketable fruit yield of capsicum varieties grown in the RRPS was significantly higher than those in the OF with fruit yields of 97 t ha−1 and 39.1 t ha−1, respectively, but the fruit quality remained unchanged. Overall, the data suggest that the RRPS altered the internal microenvironment and enhanced capsicum crop growth, physiology and fruit yield by setting climatic parameters to automatically control the opening and closing of the roof, the insect net and side curtains, and activation of the fogging system. The future perspective of the deployment of RRPS for capsicum production under climatic conditions in Carnarvon was also discussed.

Experimental and numerical study of fogging cooling performance through a cylindrical duct for a micro gas turbine

Fogging cooling is one of the most effective methods for cooling gas turbine inlet air in hot areas. Most of the previous studies focused only on the influence of the fogging cooling effect on the gas turbine performance. Nevertheless, due to the limited space available for installing a system, the fogging system requires special attention, notably in micro gas turbines, to avoid the thermal stress and blade erosion risks at a compressor intake. Hence, in the current paper, the performance of the fogging cooling system for micro gas turbines has been investigated experimentally and numerically to enhance the cooling efficiency, temperature stability and accomplish complete droplets evaporation. An experimental setup has been designed and installed to study the fogging cooling effect through a cylindrical duct. Eulerian-Lagrangian CFD model was also adopted to simulate the trajectories of the injected droplets and to predict the evaporation cooling process through the spray duct. The CFD model was validated with the current experiments, and there is good agreement between the experimental data and simulation results with an average deviation of less than 6.4%. The droplets' size and injected mass flow were measured at different nozzles orifice diameters and injection pressures to select the appropriate spray nozzles at various test conditions. The fogging performance has been tested under various operating conditions, including nozzle arrangement and flow directions, to identify the crucial factors for obtaining fully saturated air and stable temperature from the spray duct. The results reveal that employing a single nozzle to achieve full saturation is ineffective. On the other hand, increasing the number of nozzles with the same input water flow rate improves droplets distribution across the duct and enhances the evaporation rate. It was found that the temperature drop can be reduced by 1.5 °C due to dividing the required water mass flow on four nozzles instead of one. Furthermore, it was observed that the cooling performance of the counter-current flow case could be improved by 3.4% compared to the co-flow one with a high uniform temperature profile through the duct. Finally, a counter-current spray design with four nozzles is proposed for micro gas turbines since it meets the design constraints best compared to other operating scenarios.

9 Environmental Contamination Reduction Following Standard, Enhanced, and a Novel Cleaning Protocol in a Burn Center

IntroductionBurn patients are extremely vulnerable to hospital acquired infections, some of which may originate from environmental surfaces. Enhanced cleaning practices of surfaces varies from hospital to hospital. In a burn unit, patients are frequently exposed to multiple environments including the patient room, hydrotherapy and treatment rooms (treatment spaces), and the operating room. We sought to evaluate the efficacy of current protocols, including standard cleaning (SC) and cleaning with ultraviolet light application (C+UV) in the patient rooms and treatment spaces, and compare to a novel Hybrid Hydrogen Peroxide (HHP) fogging system in the patient rooms.MethodsThis study was conducted at a regional 12-bed verified adult and pediatric burn center that functions as an intensive care unit and step-down unit, where patients stay during their entire admission. Data from December 2020 to June 2021 was collected from rooms following 17 patient discharges with a minimum of a 2-week hospital stay. Data was collected from 5 preset locations in the patient rooms following either SC or C+UV and after HHP fogging. Baseline data was also collected from 20 preset locations in the treatment spaces following SC and C+UV. Quantitative and qualitative counts (aerobic colony county [ACC], adenosine triphosphate [ATP]), hydrogen peroxide chemical indicators (CIs) and bacterial spore biological indicators (G. stearothermophilus 1x106 spores) were measured.ResultsNo statistically significant difference between SC and C+UV was seen (mean ACC 7.16 and 6.35 respectively; p=0.186). ACC levels were reduced following HHP fogging demonstrating a 98% improvement over SC and C+UV (mean ACC 0.14; p< 0.0001). ATP demonstrated an 88% reduction after HHP fog without manual cleaning. Biological indicators confirmed a 1x106 reduction of bacterial spores, and CIs verified a thorough migration of HHP fog throughout the patient room. Baseline sampling of the treatment spaces following SC and C+UV resulted in a range of 0-70 ACC over 38 swabbed locations, consistent with ACC levels measured in patient rooms (range 0-153). An industry-known location for high bioburden, one sink backsplash swabbed on two separate occasions resulted in >5,700 ACC.ConclusionsIn patient rooms, HHP fogging resulted in a significant reduction in ACC compared to current protocols of SC and C+UV. Baseline sampling of the treatment spaces resulted in ACC levels similar or greater in range to those seen in the patient room, indicating a similar reduction in bioburden levels could be achieved through implementation of HHP fogging. The efficacy and feasibility of HHP fogging in a patient room setting within a burn unit suggests that a protocol for the use of HHP fogging for treatment spaces will likewise be beneficial.