Tank Size Research Articles

Boron-Doped Diamond-Film-Based Two-Dimensional Electrode of Electrophoresis Tank**Supported by the National Natural Science Foundation of China under Grant No 51472105, and the Key Program in Science and Technology of Jilin Province under Grant No 20150204062GX.

Chemically robust conductive p-type boron-doped diamond (BDD) films are an important electrode material and have been widely applied in electrochemistry. In this study, BDD films are taken as a two-dimensional (2D) electrode in a electrophoresis tank system instead of the conventional one-dimensional platinum wire electrode. The theoretical simulations by finite element numerical analysis reveal that the 2D BDD electrodes have relatively high intensity and uniformity of electric field in the tank. Experimentally, the 2D BDD electrodes with smaller size show excellent properties for the separation of DNA fragments. The advantages of the 2D BDD electrodes with chemical inertness, sustainability, high intensity and uniformity electronic field, as well as reduced small size of electrophoresis tank would open a possibility for realizing new generation, high-performance biological devices.

Performance analysis of liquefied natural gas storage tanks in refueling stations

Liquefied natural gas (LNG) could replace diesel in the transportation sector. However, fugitive emissions including boil-off gas (BOG) across the LNG supply chain have revealed uncertainties on the overall environmental benefits of such replacement. In this study, time-dependent thermodynamic models were developed to study the LNG holding time of storage tanks in refueling stations before BOG releases to the atmosphere. Previously overlooked factors, such as the thermal mass of storage tanks and the actual operating conditions at refueling stations, were included explicitly in the models. The effect of the thermal mass of storage tanks on holding time is illustrated by an analysis of 57.20 m3 storage tanks filled with LNG at −150 °C and −126.5 °C. The tank with the lower temperature fills shows 3.7-times longer holding time. Further investigations highlight the importance of the ratio of heat transfer surface area to the LNG volume as a key factor in proper sizing of storage tanks to maximize the holding time. Finally, the modeling of a 57.20 m3 storage tank with a heat transfer coefficient of 0.022 W/m2K shows that fuel delivery rates as low as 1.89 m3/day are sufficient to maintain the tank pressure within allowable limits.

Tendências no processamento de frangos de corte: uso racional da água

RESUMO Atualmente o uso racional da água vem sendo tema de discussão perante órgãos governamentais e não governamentais ao redor do mundo. Seguindo essa tendência, leis cada vez mais severas devem ser implantadas em relação ao uso desse bem natural. Em um frigorífico de frango, o uso da água ocorre de forma generalizada ao longo de todo o processo industrial. Nesse contexto, o atual estudo teve o objetivo de comparar o consumo de água em um frigorífico brasileiro de frangos de corte (grande porte) com modelos já propostos e utilizados em outros países com o intuito de identificar soluções para mitigar perdas provenientes de sua má gestão. Concluiu-se que alterações em alguns pontos-chave do processamento possibilitariam à indústria o uso mais sustentável da água, como substituição da eletronarcose por insensibilização a gás, diminuição da dimensão do tanque de escaldagem ou mudança no processo, substituição do pré-resfriamento por imersão em água por pré-resfriamento a ar, redução da renovação de água nos tanques resfriadores, alterações no sistema de geração do frio em ambientes climatizados, assim como o reúso total ou parcial da água.

Seasonal performance assessment of sanitary hot water production systems using propane and CO2 heat pumps

Heat pump water heaters can increase the energy efficiency in sanitary hot water production, which is a relevant share of the final energy consumption in multiresidential and tertiary buildings. Refrigerants for these heat pumps are changing due to the F-Gas Regulation which bans high-GWP fluids. While CO2 is an established solution, propane is a promising low-GWP alternative for heat pump water heaters serving large users in the tertiary sector, where refrigerant charge limits (due to propane's flammability) can be bypassed by installing the heat pump outdoors. Here, the components of a CO2 and a propane air-water heat pump systems of 40 kW are sized and their COPs are compared in different climates; then, the two heat pumps are coupled to a storage tank and a user demand profile (hospital and school). For three different locations, tank size necessary to maintain users' comfort and seasonal performance factor are evaluated through simulation.

Optimal design of a Thermodynamic Vent System for cryogenic propellant storage

Future operations in space exploration require to store cryogenic liquids for long duration. Residual heat loads, due to heat conduction in the launcher structure or solar radiation, induce cryogenic propellant vaporization and tank self-pressurization. The Thermodynamic Vent System (TVS) permits to control self-pressurization using the following procedure: a fraction of liquid propellant is removed from the tank by a pump, cooled down by a heat exchanger and re-injected inside the tank as a jet or a spray. As no natural heat sink is available in space, the cold source is created by removing another fraction of liquid propellant which is expanded in a Joule-Thomson valve and vented to space. The sub-cooled injection is followed by vapor condensation and liquid bath destratification due to mixing. In this work, an optimization method is applied to an extended homogeneous thermodynamic model to design a TVS system maximizing the storage duration under various heat load and tank size assumptions.

Production of Activated Carbon from Moldy Damaged Tamarind-Pod

This research studied production of activated carbon (AC) derived from tamarind pods damaged by mold. Folk wisdom kiln which manufactured from an oil tank size of 200 L was used for pyrolysis and carbonization of tamarind pod derived from sweet and sour tamarinds. The AC was produced by using chemical activation and thermal activation at the optimal condition. Then the physical and chemical properties of the AC were investigated. From the study, it was found that optimal condition for charcoal carbonization of the tamarind pod was 400 °C for 4 hrs. The optimal condition for thermal activation was 600 °C for 1-2 hrs. The phosphoric acid (H3PO4) showed higher effectiveness for activation than distillation water (H2O), potassium hydroxide (KOH) and zinc chloride (ZnCl2). The produced AC has specific surface area of 851.58-910.31 m2/g (BET Theory), a pore volume of 2.24-2.32 cm3/g with an average pore radius of 50.90 to 52.53 Å, iodine number of 613.9-654.8 mg/g, phenols adsorption of 61.7-83.1% and apparent density 0.4528 g/cm3. The results from proximate analysis shown that the AC has the moisture content of 6.81-7.54% (wt), the ash content of 6.58-7.31% (wt), the volatile matter of 38.26-40.12% (wt) and the fixed carbon of 52.57-55.16% (wt). The performance of the AC for acetic acid adsorption according to the Langmuir and Freundlich isotherm exhibited a monolayer adsorption isotherm and the AC adsorbed the acetic acid well and strength. Therefore the produced AC can be further used for filter material in small water treatment.

Nusselt’s correlations in agitated tanks using the spiral coil with Rushton turbine and PBT 45° impeller. Comparison with tanks containing vertical tube baffles

One of the main reasons for employing coils to heat and cool liquids in tanks is its low purchase cost. The technique is used in a great variety of industrial processes such as: the production of paint, food additives, pharmaceutical products, polymers and fuel. A project to design a spiral coil, which is also called “pancake coil” for a given impeller and tank size involves the determination of the overall heat transfer coefficient, which is a function of the Nusselt (Nu), Reynolds (Re) and Prandtl (Pr) numbers, besides the ratio between the bulk temperature viscosities and the wall temperature (Vi). The current article aims mainly at determining two calculation expressions for the Nusselt number, one for the pitched blade turbine (PBT) and another for the Rushton turbine (RT). The secondary objective is to compare the efficiency of heat transfer in spiral coils to vertical tube baffles. The models obtained for the PBT and RT impeller were:Nu=0.81Re0.64Pr0.33Vi0.14-PBTNu=0.10Re0.83Pr0.33Vi0.14-RTThe models had an adjusted determination coefficient (R2-sq) of 0.97 and 0.98 for PBT and RT, respectively. The work found that in spiral coil heating for Reynolds between 2000 and 60,000 the PBT is recommended and for Reynolds from 60,000 to 500,000 the RT is indicated. When comparing heating efficiency, if the process is carried out using the PBT, the spiral coil should be used. Whereas, when a RT is employed, the most adequate heat transfer surface is the vertical tube baffles.

RELIABILITY ANALYSIS OF URBAN RAINWATER HARVESTING

The purpose of this study was to inform decision makers at state and local levels, as well as property owners about the amount of water that can be supplied by rainwater harvesting systems in Texas so that it may be included in any future planning. Reliability of a rainwater tank is important because people want to know that a source of water can be depended on. Performance analyses were conducted on rainwater harvesting tanks for three Texas cities under different rainfall conditions and multiple scenarios to demonstrate the importance of optimizing rainwater tank design. Reliability curves were produced and reflect the percentage of days in a year that water can be supplied by a tank. Operational thresholds were reached in all scenarios and mark the point at which reliability increases by only 2% or less with an increase in tank size. A payback period analysis was conducted on tank sizes to estimate the amount of time it would take to recoup the cost of installing a rainwater harvesting system.

RELIABILITY ANALYSIS OF URBAN RAINWATER HARVESTING

The purpose of this study was to inform decision makers at state and local levels, as well as property owners about the amount of water that can be supplied by rainwater harvesting systems in Texas so that it may be included in any future planning. Reliability of a rainwater tank is important because people want to know that a source of water can be depended on. Performance analyses were conducted on rainwater harvesting tanks for three Texas cities under different rainfall conditions and multiple scenarios to demonstrate the importance of optimizing rainwater tank design. Reliability curves were produced and reflect the percentage of days in a year that water can be supplied by a tank. Operational thresholds were reached in all scenarios and mark the point at which reliability increases by only 2% or less with an increase in tank size. A payback period analysis was conducted on tank sizes to estimate the amount of time it would take to recoup the cost of installing a rainwater harvesting system.

Energy Management of an Off-Grid Hybrid Power Plant with Multiple Energy Storage Systems

In this paper, an off-grid hybrid power plant with multiple storage systems for an artificial island is designed and two possible strategies for the management of the stored energy are proposed. Renewable power sources (wind/solar technologies) are used as primary power suppliers. A lead-acid battery pack (BAT) and a reversible polymer electrolyte fuel cell are employed to fulfill the power demand and to absorb extra power. The reversible fuel cell allows reducing costs and occupied space and the fuel cell can be fed by the pure hydrogen produced by means of its reversible operation as an electrolyzer. A diesel engine is employed as backup system. While HOMER Pro® has been employed for a full-factorial-based optimization of the sizes of the renewable sources and the BAT, Matlab/Simulink® has been later used for simulating the plant operation and compare two possible power management control strategies. For the reversible fuel cell sizing, a sensitivity analysis has been carried out varying stack and hydrogen tank sizes. The final choice for plant configuration and power management control strategy has been made on the basis of a comparative analysis of the results, aimed at minimizing fossil fuel consumption and CO2 emissions, battery aging rate and at maximizing the power plant overall efficiency. The obtained results demonstrate the possibility of realizing a renewable power plant, able to match the needs of electrical power in a remote area, by achieving a good integration of different energy sources and facing the intermittent nature of renewable power sources, with very low use of fossil fuels.

Optimization of the inverter size for grid-connected residential wind energy systems with peak shaving

This paper addresses the problems of output power distribution and variability of small wind turbines. The aim of the study was to increase the share of locally consumed renewable energy and decrease power fluctuation in residential houses that meet their energy demand using wind energy. A system with shiftable water heating and decreased inverter power, which avoids unnecessary conversion steps for shifting of power peaks is proposed. Autocorrelation functions were used to analyse the energy consumption and production patterns for optimization of the inverter and hot water storage tank size for load shifting. The optimal sizing of these components for applying the method was found for different wind conditions. The results of simulations with high temporal resolution data and experiments showed that the proposed system is able to shave stochastic power peaks and shift electrical loads. The analysis of net energy flow revealed that the renewable energy cover factors can be enhanced by 14.4–36.0% and the wind turbine's nominal inverter power can be decreased down to 29.2–52.3% without increasing the system's energy losses or changing the hot water consumption pattern.

Evaluation of climate change impacts on rainwater harvesting

Water management is an important issue in urban design due to the growing concern of water scarcity. As a result, rainwater harvesting system has received notable attention as an alternative water source. Rainwater is one of purest form of waters and can easily be accessed via a rainwater harvesting system. In general, performance of a rainwater harvesting system is estimated based on historical rainfall data without the possible impacts of climate change on rainfall. However, rainfall pattern is likely to change in the future as a consequence of climate change that may affect the performance of a rainwater harvesting system. But research on climate change impacts on rainwater harvesting is limited. The objective of this study is to understand the plausible impacts of climate change on the performances (i.e. water savings, reliability and water security) of a residential rainwater harvesting system, based on the projected future rainfall conditions. A continuous daily simulation water balance model is developed based on behavioural analysis and yield-after-spillage criteria to simulate the performances of a rainwater harvesting system. The analysis is conducted at five locations in the Greater Sydney region, Australia.The results indicate that performances of a rainwater harvesting system will be impacted negatively due to climate change conditions in the future. It is found that a given tank size at the selected locations would not be able to supply expected volume of water under changing climate conditions in future. Water savings is going to be reduced from a rainwater harvesting system in future (e.g. 2%–14% reduction for 3 kL tank for indoor water demand). Moreover, number of days in a year to meet the water demand by a rainwater harvesting system (i.e. reliability) is likely to be reduced (e.g. 3%–16% reduction for 3 kL tank for indoor water demand). Also, the percentage of days a rainwater tank would remain completely empty is likely to increase in future (e.g. 12% in future climate conditions in comparison to 8% in historical conditions for indoor water demand). Furthermore, it is found that the performance of a rainwater harvesting system will be more affected in dry season than the wet season. The findings of the study will help water authorities and policy makers, as well the home owners to improve their understanding of climate change impact on residential rainwater harvesting system, and will assist them in selecting appropriate rainwater tank size in the context of climate change.

Tank size and fish management history matters in experimental design

To investigate the questions: (1) does tank size affect fish performance; (2) does tank size prior to an experiment affect later fish performance and (3) how does performance in experimental tanks compare with rearing in industry-scale cages, Atlantic salmon smolts were acclimatized to 190, 3 or 0.9 m3 tanks (Phase 1; 1.5 months) before redistributed to Phase 2 for 5 months. Question 1: fish in 190 m3 tank were redistributed to 0.9 m3 (190 m3 → 0.9 m3), 3 m3 (190 m3 → 3 m3), or 103 m3 (190 m3 → 103 m3) tanks. Question 2: fish in 0.9 m3 tanks were redistributed to 3 m3 tanks (0.9 m3 → 3 m3), and compared to fish from 190 m3 tank (190 m3 → 3 m3). Question 3: fish were placed directly in 3 m3 tanks, not moved (3 m3 → 3 m3), and compared to reference sea cages. Phase 2 mortality: 190 m3 → 0.9 m3 (46%), 190 m3 → 3 m3 (29%), 190 m3 → 103 m3 (19%), 3 m3 → 3 m3 and 0.9 m3 → 3 m3 (<5%). Most mortality happened shortly after transfer. Our study suggests tank size dependent performance, based on growth and feed intake that increased with tank size. 190 m3 → 103 m3 fish were more active than 190 m3 → 0.9 m3 and 190 m3 → 3 m3 fish. 190 m3 → 103 m3 tanks had lowest relative variance. Previous tank scale history affected survival, since 0.9 m3 → 3 m3 fish showed higher survival than 190 m3 → 3 m3 fish. However, previous scale history did not affect growth rate, feed intake or somatic indexes. Fish performance in 3 m3 → 3 m3 tanks did not differ from the reference sea cages. However, fish in 103 m3 tanks performed better than reference cages, suggesting potential for improved commercial production. This study demonstrates that management practices can influence fish performance and should be taken into account when designing experiments.

Tank segmentation of infrared images with complex background for the homing anti-tank missile

In an effort to achieve fast and effective tank segmentation of infrared images under complex background for the homing anti-tank missile, the threshold of the maximum between-class variance method (i.e., the Otsu method) is experimentally analyzed, and the working mechanism of the Otsu method is revealed. Subsequently, a fast and effective method for tank segmentation under complex background is proposed based on the Otsu method by constraining the image background pixels and gray levels. Firstly, with the prior information of the tank, derive the equation to calculate the number of pixels of tank according to optical imaging principle, and then use the calculated tank size to constrain the image background pixels. Secondly, employ the golden section to restrict the background gray levels. Finally, use the Otsu method to implement the segmentation of the tank. Experimental results demonstrate that the proposed method can get as an ideal result as the manual segmentation with less running time.

Biofuels briefs: DuPont supplies enzymes to QCCP

In this work three different control strategies for the production of sanitary hot water by means of an electric heat pump working with CO2 are investigated. The heat pump is a prototype, here modelled in the vapour-compression software package IMST-ART. By simulating this model, the performance of the heat pump is correlated to the boundary conditions and is scaled to different sizes, namely 1, 1.5, and 2 times larger than the reference system. After having chosen an application for which the load profile of sanitary hot water during the year is known, these heat pumps are simulated in a TRNSYS16 model where the production of sanitary hot water and the consumption are buffered by the presence of a tank. Key parameter in guaranteeing comfort and good performance of the system is the stratification inside the storage tank. The size of the tank necessary to keep a certain level of comfort at the user is then determined through a parametric analysis for each size of the heat pump. The energetic performance is also evaluated for each system in terms of seasonal performance factor. Then, the results obtained are compared with a different system where the heat pump is equipped with an inverter and the circulation pump follows a different control logic. The size of the tank and the seasonal performance factor are therefore determined in this case too. Moreover, a “night&day” control logic is compared to these first two options to have a baseline of comparison in terms of volume of storage needed to guarantee a same level of comfort and performance. To provide information also on the running costs, a parametric analysis was run varying the type of control, the heat pump and the tank sizes for different load profiles.The results show that the size of the heat pump has a significant effect on the comfort of the user, which usually leads to oversizing of the storage tank when the load profile is unknown. With regard to this, the results obtained for the alternative control system show a 20% reduction of the volume of the tank, given a certain level of comfort, and is therefore useful to reduce the size of the storage tank.

Performance of a swimming pool heating system by utilizing waste energy rejected from an ice rink with an energy storage tank

This study deals with determining the long period performance of a swimming pool heating system by utilizing waste heat energy that is rejected from a chiller unit of ice rink and subsequently stored in an underground thermal energy storage (TES) tank. The system consists of an ice rink, a swimming pool, a spherical underground TES tank, a chiller and a heat pump. The ice rink and the swimming pool are both enclosed and located in Gaziantep, Turkey. An analytical model was developed to obtain the performance of the system using Duhamel’s superposition and similarity transformation techniques. A computational model written in MATLAB program based on the transient heat transfer is used to obtain the annual variation of the ice rink and the swimming pool energy requirements, the water temperature in the TES tank, COP, and optimum ice rink size depending on the different ground, TES tank, chiller, and heat pump characteristics. The results obtained from the analysis indicate that 6–7years’ operational time span is necessary to obtain the annual periodic operation condition. In addition, an ice rink with a size of 475m2 gives the optimum performance of the system with a semi-Olympic size swimming pool (625m2).

Cost-optimal thermal energy storage system for a residential building with heat pump heating and demand response control

This study aims to define a cost-optimal solution based on demand response (DR) actions for a thermal energy storage system with a ground source heat pump in detached residential houses in a cold climate. This study finds out the minimum life cycle cost (LCC) of thermal energy storage over the period of 20years by observing different temperature set points (55–95°C) and sizes (0.3–1.5m3) of a hot water storage tank with developed DR control algorithms. Three different control algorithms were studied: (A) a momentary DR control algorithm based on real-time hourly electricity price (HEP), (B) a backwards-looking DR control algorithm based on previous HEPs and (C) a predictive DR control algorithm based on future HEPs. This research was carried out with the validated dynamic building simulation tool IDA Indoor Climate and Energy. The results show that by using the predictive DR control algorithm the maximum annual savings in total delivered energy and cost are about 12% and 10%, respectively. The minimum LCC can be achieved by the smallest studied storage tank size of 0.3m3 with 60°C as the temperature set point, but the effect of storage tank size on LCC is relatively small.

CHARACTERISTICS OF MOLTEN SALTS AND RECOMMENDATIONS FOR USE IN SOLAR POWER STATIONS

Molten salts (MS) in the 580°C range could be used to store excess energy from solar power stations and possibly from nuclear or coal. The energy can be stored up to a week in large containers at elevated temperature to generate eight hours of electricity to be used at night or during peak demand hours. This helps to reduce the fluctuation experienced at thermal solar power stations due to weather conditions. Our research supported by Office of Naval Research (ONR), presents a survey of salts to be used in molten salt technology. The physical characteristics of these salts such as density, melting temperature, viscosity, electric conductivity, surface tension, thermal capacity and cost are discussed. Cost is extremely important given the large volumes of salt required for energy storage at a commercial power station. Formulas are presented showing the amount of salt needed per required megawatts of stored energy depending on the type of salt. The estimated cost and the size of tanks required and the operating temperatures are presented. Recommendations are made regarding the most efficient type of molten salt to use. Commercial thermal solar power stations have been constructed in the US and overseas mainly in Spain for which molten salt is being considered. A field of flat mirrors together with collection towers are used in some designs and parabolic troughs used in others.

Tank size alters mean behaviours and individual rank orders in personality traits of fish depending on their life stage

Animals adjust their behaviour over time and contexts to cope with ecological and environmental variation. However, the presence of consistent between-individual differences in behaviour (i.e. personality) suggests that individual behaviour may be less flexible than previously thought. Here, we tested whether the size of the experimental tank and the ontogenetic stage of individuals affect estimates of average and consistent individual variation in activity and risk-taking behaviours in the eastern mosquitofish, Gambusia holbrooki, a fish model widely utilized for behavioural research. We measured risk taking and activity in juvenile, subadult and adult mosquitofish in a standard open-field test, in which the size of test tank varied linearly. We found strong evidence that spatial constraints alter mosquitofish behaviour. In particular, we observed that average activity increased with tank size, while the willingness of fish to take risks was independent of tank size. Moreover, juvenile fish exhibited, on average, lower risk-taking behaviours than older individuals. We highlight that the use of differently sized tanks may result in unequal variation in the average behaviour between juvenile and older fish, with escaping abilities of juvenile fish being underestimated in small environments. Most interestingly, we observed that variation in tank size triggered changes in the individual rank order for both risk taking and activity in juvenile fish, thus altering their personality estimates. In contrast, adult fish maintained consistent individual rank orders across all tank sizes. This study supports the hypothesis that behavioural repeatability increases with age, suggesting that personality estimates on adult animals may be less vulnerable to variation in laboratory contexts than those on juvenile ones.

Assessing Marginalized Communities in Mexico for Implementation of Rainwater Catchment Systems

Mexico contains a high percentage of marginalized communities, as well as geographic areas with high annual precipitation (approximately 2000 mm). This study uses regional water access and precipitation data to determine municipalities that would most benefit from the installation of Domestic Rain Water Harvesting Systems (DRWHS). The main objective was to find a relationship between local conditions (marginalization, expected level of service, and precipitation) and the physical components of DRWHS. First, monthly precipitation and the number of inhabitants per household were determined for each municipality. Catchment area and tank size were then calculated for a single dwelling by municipality using water demand, run-off coefficient, monthly precipitation, and number of inhabitants per household. In general, municipalities with very low access to municipal water and very high precipitation were found in the southern area of the country. A curve that estimates catchment area based on annual precipitation was developed using the selected municipalities, which produced an average catchment area of 113.3 m2 for a water demand of 100 L/capita/day. While any DRWHS must be designed specific to local conditions, this study has determined that a regional approximation can be used to select ideal communities for these systems, which can in turn facilitate national implementation.