Tank Size Research Articles

Rainwater Harvesting Tank Sizing: A Case in Urban Catchments in Metro Cebu

Rainwater is an abundant resource in the Philippines and when properly collected and managed, can help address flood problems. Rainwater harvesting has been practiced for years and has been viewed as one of the better options for flood mitigation in urban areas compared to other storm water management practices. It does not require large land area and cost per area is high in these locations. However, there is a challenge in selecting the suitable tank size. This paper investigates if the increase in stormwater runoff brought about by the changes in landuse in urbanized catchments can be represented by a single coefficient similar to what is being presented in the Philippine Green Building Code and in other local ordinances in the country. Simulations through HEC-HMS of three urban catchments in Metro Cebu showed that the increase in volume is highly varying such that the coefficient produced for each catchment was so distinct that no single average coefficient can be drawn. Thus, analysis should be catchment-based to determine the suitable tank size in rainwater harvesting systems as an option for flood mitigation.

Long-Term Continuous Computer Registration and Analysis of Motor Activity of a Group of Zebrafish Danio rerio.

A new algorithm for long-term continuous computer recording and analysis of motor activity of a group of zebrafish in the home tank has been developed. The movements of a group of Danio rerio during the entire light period and for several days are recorded at a frequency of 1 frame/sec in the form of short (15 min) files. Then these files are analyzed by the unique DanioStudo software, which, using a threshold algorithm and appropriate masks, calculates for each frame the sum of pixels associated with fish (the sum of fish silhouettes), and for two consecutive frames, the sum of altered pixels (the sum of altered fish silhouettes). The following indexes are calculated: the rate of sum of silhouettes alteration as the ratio of the sum of altered silhouettes to the sum of silhouettes (1) and the time spent in the selected area of the home tank as the ratio of the sum of silhouettes in this area to the sum of silhouettes in the entire tank (2). The mean rate of silhouette alteration correlates to the length of the path travelled by the fish and, therefore, serves as a correct measure of the motor activity of a group of fish. Using these algorithms, completely new data were obtained: it was shown that the motor activity of fish remains constant throughout the entire light period, but depends on the size of the home tank. The proposed approach, together with the DanioStudio software, can be effective in studying the dynamics of changes in the behavior of fish under long-term exposure to short daylight, drugs and toxic substances.

Improving the procedure for modeling low-frequency oscillations of the free surface liquid in a tractor tank

This paper considers the influence of hydrodynamic processes in the movement of the free surface of liquid in partially filled tractor tanks. Splashing liquid in partially filled containers is a significant problem in the study of functional stability of movement in the marine, aerospace, rail, and automotive industries. After all, it affects productivity and traffic safety. The same effect was observed when performing transportation work while delivering liquid cargoes in the agricultural sector. That was due to increasing the transportation speeds of wheeled tractors. In the procedure, using the Rayleigh theory of surface waves, a linearized problem of motion of the free surface of a liquid is obtained. Based on Helmholtz's theorem, the components of scalar and Laplace field vector potentials of fluid velocity vector are separated. The potential problem for translational motion of fluid, in which vortex component of the field is absent, is considered. Instead of the fluid velocity potential, a scalar fluid displacement potential in Rayleigh surface waves was introduced. Comparing the results of calculating fluid splashing with the work of other scientists, a high convergence of natural frequencies of partial oscillators in 3D space was found. This is noticeable in the last quarter of the filling of the tank, in which significant displacements of the deep liquid occur. A feature of the results is the introduction, instead of the real shape of the container, an equivalent form of a parallelepiped, the final shape of which depends on the level of fullness. The frequency properties of movement of the free surface of liquid based on the standard size of tanks used in agriculture are separated. The proposed improved methodology could be used to increase stability, controllability, and smoothness when operating tanks with a wheeled tractor.

Analysis of various design parameters of a desert cooler

ABSTRACT Aside from climatic parameters, the cooling potential of a desert cooler is influenced by fan flow rate, pad thickness, and pad packing factor, all of which are referred to as cooler parameters. In this study, a general equation for determining cooling potential in terms of cooler parameters is proposed and validated. An equation has been devised to determine the combination of fan flow rate (FFR) and pad area required to meet a given heating load. The equation aids in the sizing of coolers for a desired room temperature in various climates. The size of the cooler tank is determined by the rate of water evaporation. In this investigation, we evaluated the influence of different fan flow rates on the rate of water evaporation. It is seen that at a typical set of climatic parameters and for a given pad (1 m2, 350 m2/m3, 10 cm thick), the cooling potential of the cooler increases by increasing fan flow rate (. Furthermore, increasing pad area reduces the amount of fan flow rate required for a given heating load, allowing one to select the appropriate combination of fan flow rate and pad area. Higher fan flow rates increase the running cost, while increasing pad area raises the initial investment cost. The pad area needed (10 cm, 350 m2/m3) for the composite climate of Delhi at a 0.35 m3/s FFR, is roughly 66.7% less than that for the hot climate of Jodhpur for 4 kW heating load.

On-site solar PV generation and use: Self-consumption and self-sufficiency

As energy storage systems are typically not installed with residential solar photovoltaic (PV) systems, any “excess” solar energy exceeding the house load remains unharvested or is exported to the grid. This paper introduces an approach towards a system design for improved PV self-consumption and self-sufficiency. As a result, a polyvalent heat pump, offering heating, cooling and domestic hot water, is considered alongside water storage tanks and batteries. Our method of system analysis begins with annual hourly thermal loads for heating and cooling a typical Australian house in Geelong, Victoria. These hourly heating and cooling loads are determined using Transient System Simulation (TRNSYS) software. The house’s annual hourly electricity consumption is analysed using smart meter data downloaded from the power supplier and PV generation data measured with a PV system controller. The results reveal that the proposed system could increase PV self-consumption and self-sufficiency to 41.96% and 86.34%, respectively, resulting in the annual imported energy being reduced by about 74%. The paper also provides sensitivity analyses for the hot and cold storage tank sizes, the coefficient of performance of the heat pump, solar PV and battery sizes. After establishing the limits of thermal storage size, a significant impact on self-efficiency can be realised through battery storage. This study demonstrates the feasibility of using a polyvalent heat pump together with water storage tanks and, ultimately, batteries to increase PV self-consumption and self-sufficiency. Future work will concentrate on determining a best-fit approach to system sizing embedded within the TRNSYS simulation tool.

Novel Husbandry Practices Result in Rapid Rates of Growth and Sexual Maturation Without Impacting Adult Behavior in the Blind Mexican Cavefish.

Animal model systems are dependent on the standardization of husbandry protocols that maximize growth and reduce generation time. The Mexican tetra, Astyanax mexicanus, exists as eyed surface and blind cave dwelling populations. The opportunity for comparative approaches between independently evolved populations has led to the rapid growth of A. mexicanus as a model for evolution and biomedical research. However, a slow and inconsistent growth rate remains a major limitation to the expanded application of A. mexicanus. Fortunately, this temporal limitation can be addressed through husbandry changes that accelerate growth rates while maintaining optimal health outcomes. Here, we describe a husbandry protocol that produces rapid growth rates through changes in diet, feeding frequency, growth sorting and progressive changes in tank size. This protocol produced robust growth rates and decreased the age of sexual maturity in comparison to our previous protocol. To determine whether changes in feeding impacted behavior, we tested fish in exploration and schooling assays. We found no difference in behavior between the two groups, suggesting that increased feeding and rapid growth will not impact the natural variation in behavioral traits. Taken together, this standardized husbandry protocol will accelerate the development of A. mexicanus as a genetic model.

Techno-economic analysis of a combined heat and power system integrating hybrid photovoltaic-thermal collectors, a Stirling engine and energy storage

This paper presents a comprehensive analysis of the energetic, economic and environmental performance of a micro-combined heat and power (CHP) system that comprises 29.5 m2 of hybrid photovoltaic-thermal (PVT) collectors, a 1-kWe Stirling engine (SE) and energy storage. First, a model for the solar micro-CHP system, which includes a validated transient model for the SE micro-CHP unit, is developed. Parametric analyses are performed throughout a year to evaluate the effects of key component sizes and operating parameters, including collector flow rate, storage tank size, SE micro-CHP flow rate, and battery capacity, on the energetic, economic and environmental performance of the proposed system using real hourly weather data, and thermal and electrical energy demand profiles of a detached house located in London (UK). The optimum component sizes and operating parameters are determined accordingly. The daily and monthly operating characteristics of the system are evaluated, and its annual performance is compared to those of a reference system (gas boiler plus grid electricity), as well as of other alternative solar-CHP systems including a PVT-assisted heat pump system and a standalone PVT system. The results indicate that the installation of such a system can achieve an annual electricity self-sufficiency of 87% and an annual thermal energy demand coverage of 99%, along with annual primary energy savings and carbon emission reduction rate of 35% and 37% relative to the reference system. Over 30 years of operation, the net present value (NPV) of the proposed system is £1990 and the discounted payback period is 28 years. The economics of the proposed system is very sensitive to utility prices, especially the electricity purchase price. Relative to the alternative solar systems, the proposed system offers greater environmental benefits but has a longer payback period. This implies that although the energy saving and emission reduction potential of the proposed system is significant, the initial/capital investment, especially of the SE CHP unit and the PVT collector array, are currently high, so efforts should focus on the cost reduction of these technologies.

Optimal design of water reuse networks in cities through decision support tool development and testing

Water scarcity and droughts are an increasing issue in many parts of the world. In the context of urban water systems, the transition to circularity may imply wastewater treatment and reuse. Planning and assessment of water reuse projects require decision-makers evaluating the cost and benefits of alternative scenarios. Manual or semi-automatic approaches are still common practice for planning both drinking and reclaimed water distribution networks. This work illustrates a decision support tool that, based on open data sources and graph theory coupled to greedy optimization algorithms, is able to automatically compute the optimal reclaimed water network for a given scenario. The tool provides not only the maximum amount of served reclaimed water per unit of invested cost, but also the length and diameters of the pipes required, the location and size of storage tanks, the population served, and the construction costs, i.e., everything under the same architecture. The usefulness of the tool is illustrated in two different but complementary cities in terms of size, density, and topography. The construction cost of the optimal water reclaimed network for a city of approximately 100,000 inhabitants is estimated to be in the range of €0.17–0.22/m3 (for a payback period of 30 years).

Influence of Design Variables on the Financial Feasibility of Rainwater Harvesting Systems

Extensive implementation of rainwater harvesting (RWH) systems can promote substantial improvement in urban water resource management. Therefore, establishing the financial feasibility of RWH systems is imperative for their dissemination. This study evaluated the influence of rainfall time series indicators (average annual rainfall, seasonality index and behaviour of periods without precipitation) and design variables (catchment area, rainwater demand, number of inhabitants, potable water demand and rainwater tank size) on the financial feasibility of RWH systems in eight Brazilian cities. Correlations between rainfall indicators and financial feasibility were introduced, along with sensitivity analysis of design variables. Financial feasibility was obtained in 30% to 70% of the simulated scenarios. Initial investment and operating costs varied significantly among the eight cities according to local prices. Systems with a catchment area of 200 m2 were capable of supplying, on average, 90.5% of the maximum rainwater consumption observed in this study. Local variation of potable water tariff schemes affected the financial feasibility of RWH systems. The number of inhabitants was the most influential design variable on the financial feasibility of RWH systems, followed by the rainwater tank size. Places with lower rainfall seasonality indexes and lower incidence and duration of dry periods are likely to lead to greater financial feasibility.

A Study on the Control System of Electric Water Heaters for Decarbonization

Greenhouse gas (GHG) emissions have significantly increased in recent years as a result of population rise and the increase in the number of residences, with high levels of energy use in homes and household appliances. It is crucial to move the housing industry away from high-carbon sources and toward low-carbon sources in order to minimize greenhouse gas emissions as a precaution. One of the most crucial systems that needs to be provided in order to achieve energy efficiency is the electric water heater (EWH), as they rank among the top electricity consumers. In this study, a double-tank EWH model was developed and simulated at various tank sizes (100 L, 200 L, 300 L and 400 L) and power ratios (1 kW, 2 kW, 3kW and 4 kW) in order to demonstrate energy efficiency. To obtain information for the simulation analysis of the tanks, the hourly water usage of 25 houses was measured. The single-tank and the double-tank models created for this study were both run in the Matlab/Simulink environment with an on-off controller applied, and their energy consumption was compared. Amounts were also determined based on how much energy both tanks consumed. It has been noted that the amount of GHG emissions is also reduced because the double tank uses less energy than the single tank does. The simulation showed that compared to the single tank, the dual tank produced 46.62% less GHG emissions at 45 W power and 47.51% less GHG emissions at 80 W.

Design and simulation of a novel solar photovoltaic system assisted single‐slope solar still distillation unit

AbstractWater is an essential component of our lives. Conventional seawater desalination, based on fossil fuel energy, is primary in meeting freshwater demands. Thus, solar desalination still emerged as an alternative technology that employs environmentally friendly renewable energy. Here, we aim to design and simulate a novel hybrid solar photovoltaic (PV) system coupled with a single‐slope solar still unit for freshwater production. Various design techniques were utilized to fine‐tune the model towards producing 3–4.6 kg/m2 · day of distillate water, thereby calculating the design aspects such as tank size, energy, and cost. The results revealed that a conventional solar desalination system had 22% lower efficiency than the proposed novel still distillation unit assisted with a solar PV system (connected to a heating element). The maximum efficiency of 45% has been recorded at the peak solar insolation due to the combination of the solar PV system. According to our design constraints, only a 3 m2 basin area was required to achieve a productivity of = 1–5 kg/day. Design analysis showed that the total capital cost of a conventional still can be significantly reduced from 2600 to 1500 $/unit with PV system integration at the specified productivity and optimal solar radiation of ~17 MJ/m2 · day at peak time (02.00 PM). This work paves the way towards maximizing solar energy utilization from PV integration with solar desalination to achieve high freshwater productivity in single‐basin solar still systems.

Potential of rainwater harvesting in the retail sector: a case study in Portugal

Water is a crucial resource for life, and it is increasingly scarce in many regions of the globe. In addition, retail water use is responsible for up to 19% of public water globally supplied. Hence, this study has set out to explore the technical and economic feasibility of rainwater harvesting systems as an alternative water source for a retail store located in southern Portugal. Water consumption data from 2018 to 2021 was collected from water bills, placing average monthly water consumption at around 400 m3. Next, rainfall data was collected from the nearest meteorological station, comprising 54 years of daily rainfall data between 1932 and 2008 with an annual average of 685 mm. The simulation of a rainwater harvesting system was performed, resorting to the mass-balance model. The optimal tank size was found to be 100 m3 considering simply the relation with the relative water savings variation on the graph relating the water savings with the tank size. Results show that the simulated rainwater harvesting system would allow saving 32–36% of the water consumed, despite the store’s location in a dry climate, representing a financial gain of €330–372 per month. Findings suggest a substantial potential for the technical and economic feasibility of rainwater systems in retail stores, which makes them relevant solutions to achieve important water-savings in the retail sector, thus positively influencing retailers’ direct water footprint.

Review of the design considerations for the laboratory growth of sea ice

AbstractSample collection and field studies of sea ice take place under harsh conditions which, combined with the logistical difficulties and high cost of voyages to the polar regions, limits the abilities of researchers to determine its properties. Observations of laboratory-grown sea ice can help quantify important sea-ice properties and incorporate them into numerical models. The growth of laboratory sea ice requires experimental set-ups that consider the complexity of sea-ice growth. Regulation and monitoring of environmental variables allow for growth and melt conditions to be controlled, manipulated and reproduced. Facilities thus vary widely because of differing research objectives. This paper presents a summary of some of the published sea-ice laboratories that study the physical properties of sea ice and an overview of their major design considerations, such as tank size, freezing method and instrumentation. It also discusses how these design considerations were implemented in the set-up of the new sea-ice growth laboratory at the Marine and Antarctic Research for Innovation and Sustainability. This paper should guide others in designing their facilities as well as in their understanding of other facilities for results comparison.

Analytical modelling of food storage cooling with solar ammonia-water absorption system, powered by parabolic trough collectors. Method

The study presents a new analytical model capable to reveal the thermal behaviour of all the components of the solar ammonia-water absorption system, powered by parabolic trough collectors, serving different types of food storages: refrigeration chamber, refrigerated food storage, freezing chamber and frozen food storage. The heat inputs, that determine the total cooling load, for each food storage spaces consist of: heat gains through walls, heat gains through ventilation (fresh air), heat that must be dissipated from the stored products (technological cooling load required to cool down the products) and heat gains through operation. The influence of the number of solar parabolic trough collectors and of the storage tank size on different parameters of the refrigeration plant are investigated under low and high storage temperatures.•Food cooling with solar absorption refrigeration system.•Hourly based variation of NH3-H2O solar absorption system performances.•Long term simulation of solar absorption cooling for refrigeration and cooling.

Transportation and Acclimation Optimisation of Wild Marble Goby (Oxyeleotris marmorata Bleeker, 1852)

The Marble goby (Oxyeleotris marmorata Bleeker) is usually found in freshwater bodies. Due to its high commercial value and demand, it is farmed in cages and pond systems. Marble goby fish are preferred to be freshly killed and processed upon request in Asian restaurants. Currently, there are some challenges faced by fishermen who wish to transport live fish to restaurants or markets due to the traditional method of using water tanks as carriers. These water tanks are usually very heavy and bulky, increasing transportation costs. Furthermore, coping with the survivability of fish post-transportation has proven to be a challenge. This study was aimed at investigating the semi-dry method for fish transport and acclimatization of fish after transport in different tank sizes. In the semi-dry, where fish were covered using a towel transportation method where the survival rate at ~92%. For the acclimation experimental group, stream water was found to be the most appropriate type of water for rearing the marble goby fish, which demonstrated a conspicuous survivability rate of ~83%. whereas, for adaptation, marble goby fish from the wild had a faster adaptation rate in smaller spaces like aquariums as compared to large ‘stock tanks.’ To the best of our knowledge, this is the first study that will provide a better understanding of the transportation method, acclimation conditions, and habitat that can lead to a reduction in the mortality rate during the marble goby transit processes.

Divulging the social sex change mechanism in a unique model system for studying the sexual plasticity of protogynous hermaphrodite fish, three bamboo leaf wrasse (Pseudolabrus sieboldi)

The gonadal sexual fate of vertebrates is either defined by genetics or environment, or a combination of both factors. Interestingly, in sequential hermaphroditism, the animal can undergo natural sex changes from female-to-male, male-to-female, and bidirectional way throughout their lives. This change exhibits the process which shifts between oogenesis and spermatogenesis and is regarded as an ideal instance of sexual plasticity. To develop the experimental model for studying the sexual plasticity of protogynous fish, the social conditions that induce sex changes were defined in wrasse, Pseudolabrus sieboldi. When six females were kept together in a tank, the largest female became a male, whereas a similar conversion did not occur when only two females were present in a tank. A semi-gonadectomy analysis developed in the present study verified the direct relationship between gonadal sex and body coloration. In P. sieboldi, the sex change is controlled by the relative body size of an individual within a group, rather than by absolute body size. When six females were kept in smaller sized tanks, delayed sex change or unchanged individuals was observed. Overall, more than 90% of the largest females demonstrated sex change after being housed with five smaller females in different sizes of tanks ranging from 80 to 500 L. Furthermore, the experiment using a transparent barrier suggested that visual stimuli are one of the major cues to initiate sex change. Our findings on the laboratory conditions leading to the initiation of sex change in wrasse suggest the usefulness of this species as a model organism for comparative studies in molecular, cellular, and physiological mechanisms of sexual plasticity, as well as on social and reproductive behaviors.

The Effect of Chimney Size on Knock-Down Pyrolysis Tank Design as Rice Husk Burner Using CFD Simulation

This study reports the simulation of rice husk pyrolysis units in various sizes of chimneys to investigate the effect of chimney diameter on temperature and heat distribution. The modeling design was carried out using Solidworks 2020 software with 3d modeling, and flow simulation features where the diameters of the chimneys were varied, namely 3, 4, 5, 6, and 8 inches. Simulation of the pyrolysis process with an input temperature of 450 °C and an average fluid velocity of 2.344 m/s for chimney diameters of 3, 4, 5, 6, and 8 inches has resulted in a condenser heat-temperature (TH) of 169.84 °C, 170.04 °C, 171.36 °C, 170.31 °C, and 168.05°C. It produces cold-temperature (TC) of 41.97 °C, 42.88 °C, 42.31 °C, 42.38 °C, and 45.35°C, respectively. The simulation results also show that the larger the chimney size of the pyrolysis tank, the greater the need for heat from the stove fire; conversely, the tank capacity of the husk becomes smaller.

Tank acoustics substantially distort broadband sounds produced by marine crustaceans.

Marine crustaceans produce broadband sounds that have been mostly characterized in tanks. While tank physical impacts on such signals are documented in the acoustic community, they are overlooked in the bioacoustic literature with limited empirical comparisons. Here, we compared broadband sounds produced at 1 m from spiny lobsters (Panulirus argus) in both tank and in situ conditions. We found significant differences in all sound features (temporal, power, and spectral) between tank and in situ recordings, highlighting that broadband sounds, such as those produced by marine crustaceans, cannot be accurately characterized in tanks. We then explained the three main physical impacts that distort broadband sounds in tanks, respectively known as resonant frequencies, sound reverberation, and low frequency attenuation. Tank resonant frequencies strongly distort the spectral shape of broadband sounds. In the high frequency band (above the tank minimum resonant frequency), reverberation increases sound duration. In the low frequency band (below the tank minimum resonant frequency), low frequencies are highly attenuated due to their longer wavelength compared to the tank size and tank wall boundary conditions (zero pressure) that prevent them from being accurately measured. Taken together, these results highlight the importance of understanding tank physical impacts when characterizing broadband crustacean sounds.

Assessment of Rainwater Harvesting Facilities Tank Size Based on a Daily Water Balance Model: The Case of Korea

Factors affecting rainwater resource management for the present and future include population growth, urbanization, and climate change. Rainwater harvesting (RWH) allows multiple urban water-related issues to be mitigated. In this study, a spreadsheet-based daily water balance model was developed to analyze the existing laws and regulations regarding the storage tank size of RWH facilities. Six buildings at different locations were selected for this study. Two are office buildings, two are school buildings, and two are sports buildings. The term “RWH facility evaluation criteria” is collectively used for rainwater supply satisfaction rate, rainwater guarantee rate, and rainwater utilization rate. A green roof can hold the rainwater for some time, reducing the peak flow and runoff volume. The results provide evidence that, among the selected studied buildings, buildings having a combination of a green roof and RWH facility score the highest in terms of RWH facility evaluation criteria, even though the actual tank size is much smaller than the standard tank size. This is the case with the Yesan County Office, in which a green roof connected to a small (66 m3) rainwater storage tank is installed. As a green roof can decrease the runoff volume, the rainwater can be managed efficiently with less pumping energy and only a small storage tank.

Optimization of collector area and storage volume in domestic solar water heating systems with on–off control—A thermal energy analysis based on a pre-specified system performance

Numerical simulations of solar water heating systems using on–off control were performed for four locations in the Portuguese territory, two collector types, and a wide range of parameters. Two main design parameters were considered: the collector area and the storage volume. An innovative technique was used to investigate the relationship between system performance and system parameters: a pre-specified annual solar fraction is selected and the optimal parameters needed to achieve this solar fraction are then computed. The optimum collector area is almost always higher for a double-glazed than for a single-glazed collector, suggesting that in Portugal, the single-glazed type is more effective for most solar water heating applications. This fact is more significant for lower solar fractions and warmer climates. A small increase in the optimum collector area leads to a very strong decrease in the optimum storage volume (an area increase of 1% leads to a volume decrease of 27%). Collector flow rate and storage volume increments result in lower collector areas. However, high flow rates lead to high pumping losses and lower collector efficiencies, and when the storage tank losses are significant, higher tank sizes may lead to higher collector areas. The solar fraction has a very strong impact on the collector area and storage volume (when the solar fraction increases from 0.5 to 0.99, the optimum collector area and storage volume increase about 17 and 56 times, respectively).