Optimization of aquaculture systems in Spain (original) (raw)
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Biosystems Engineering, 2007
This work analyses the effect that the electrical market liberalisation has on the variation of water temperature regimes in intensive aquaculture plants, and more specifically, the fishfarms which take advantage of the cooling effluents from power plants. Data were obtained from a facility devoted to the European eels growth which takes the warm water from the cooling effluent from the Puente Nuevo thermal power plant (Co´rdoba, Spain). The results indicate that the liberalisation of the electrical network has a significant influence on the form and quantity of energy generated by the thermal power plant, and consequently on the thermal regimes of the cooling effluent. A decrease in the mean water temperature (mean water temperature before liberalisation ¼ 25Á5 1C and after liberalisation ¼ 24Á3 1C) and an increase of variation range of water temperature (standard deviation before liberalisation ¼ 1Á7 1C and after liberalisation ¼ 2Á5 1C) inside the fishfarm were observed (without modify the management scheme of the production system) when the electrical market liberalisation was implemented. The growth potential of reared eels estimated from a growth capacity index (GCI) showed significant differences between the mean values in the regulated and liberalised electrical markets. The decrease in the value of GCI was 6Á67% when the electrical market liberalisation was implemented.
2019
This study reports on the design, construction and performance evaluation of a domestic gas oven. The oven was designed and was fabricated with an outer dimension of 860 mm length × 660 mm width × 1150 mm height made up of mild steel and the inner dimension of 759 mm length × 559 mm width × 835 mm height made up of mild steel and fiber glass of 40 mm thickness was used as an insulator to reduce cost to a minimal level. The aim of this research work is to improve on the already existing gas baking oven through the incorporation of a vent/chimney for removal of humid air and roller (wheels) for easy movement. Cooking gas is supplied to the burner located in the lower chamber of the oven via a pipe connection to the gas cylinder. Perforations allow for heat dissipation within the lower chamber. Capacity of the baking oven is 12 loaves of bread of 0.5 kg per bread per tray (batch). Using a temperature regulator and from practical determination, the maximum temperature of 210°C was recorded. The performance test on the oven showed that the efficiency of the oven is of 90.7 percent. The oven can be adapted for both domestic and industrial
Aquatic Science and Fish Resources (ASFR)
Temperature control presents a high cost for recirculating aquaculture systems (RAS). It is necessary to find a solution that would save energy in RAS. A heat balance for recirculating aquaculture system was developed on python program and a heat predicting model on graphic interface user (GUI) was produced with the given name of RAS designer and operation assistant. The model can predict precisely the heat energy required to be added or removed to maintain the water temperature at optimum water temperature to guarantee fish welfare and productivity. The model was validated by comparing predicted heat energy to actual heat energy. The model can predict the total annual, monthly, daily, hourly and extreme condition heating requirements, solar radiation, and water temperature.The predicted temperature of the water in the tank by the model ranged from 21.96 ºC to 33.26 ºC with an average of 27.92 ºC ± 1.34 ºC. on the other hand the actual temperature of the water in the tank ranged from 22.20ºC to 30.90ºC with an average of 28.41 ºC ± 1.16 ºC. The model gives good and promising results that are relatively realistic.
Modeling the thermal performance of an aquaculture pond heating with greenhouse
Building and Environment, 2007
A transient analytical model is presented to study the effectiveness of an even shape greenhouse used for heating the aquaculture pond during extreme winters. The model was solved for the climatic conditions of Delhi (Latitude: 28135 0 N), representing the northern India (comprising the states of Haryana, Punjab, Uttarakhand and Himachal Padesh) for the typical day (20th January) of winter. A simple trapezoidal design of aquaculture pond is proposed. Parametric studies involved the effects of length, breadth, depth, inclination of lining of fishpond, depth of water and air change in the greenhouse on the water heating in the fishpond. The performance of fishpond was assessed in terms of temperature gain, mean thermal efficiency and thermal load leveling. The optimum parameters for fishpond were 30 m length, 16 m breadth, 1.25 m depth, 1.0 m water depth, 751 lining inclination, and 8 air changes per hour for maximum temperature gain, maximum thermal efficiency and minimum thermal load leveling. A 20 1C rise in water temperature could be achieved during the day and 11 1C in the month of January. The maximum heat gain and loss are at around 16:00 and 7:00 h of the days, respectively.
Energetic Performance Assessment of a Thermo-Solar Greenhouse Fish (Nile Tilapia) Hatchery
Misr Journal of Agricultural Engineering
Energetic performance of a thermo-solar greenhouse representing a fish hatchery system was suggested, developed and investigated. The developed system was mainly consisted of a double cover greenhouse coupled with solar collector and heat exchanger for water heating. The main aim was to control the water environment, namely temperature and dissolved oxygen, of a fish (Nile Tilapia) hatchery at the desired levels. The main experimental work was carried out during the period from December 2014 to February 2015. The suggested and investigated system based mainly on solar energy as the source of power. However, an auxiliary heating system, namely an electric heater was used upon request. The experimental system was constructed and investigated at the research farm, Faculty of Agriculture, Kafrelsheikh University (31.07 o N and 30.57 o E) Kafrelsheikh governorate, Egypt. Environmental parameters; namely temperature, solar radiation, relative humidity, wind speed and water quality in terms of dissolved oxygen were monitored. The results indicated an efficient control in water temperature and quality. The average temperature and dissolved oxygen concentration of fish pond water throughout the whole experimental period were 26.8 (SD = 0.15) °C and 7.62 (SD =0.68) ppm respectively. The average value of air temperature rise inside the greenhouse was 8.4 °C. The average value of total daily water energy gained via the heat exchanger system was 18.185 MJ/ day per m 2 of the fish pond water surface area at an average value of 13.433 MJ/ (m 2 .day) of the incident solar radiation on the horizontal plane. As a conclusion the weekly average percentage of energy
SIMULATION MODEL FOR AQUACULTURE POND HEAT BALANCE: I MODEL DEVELOPMENT
The prediction of aquaculture pond temperatures throughout the year is essential to the design and evaluation of potential aquaculture sites. An energy balance was developed for earthen aquaculture ponds to 1) determine the relative importance of energy transfer mechanisms affecting pond temperature; 2) predict pond temperatures, and 3) estimate the energy required to control pond temperatures. A computer program was developed to solve the energy balance using weather and pond temperature data. Initial simulations for aquaculture pond validated the model’s ability to predict pond temperature changes. The dominant energy transfer mechanisms for ponds were solar radiation, pond radiation and longwave sky radiation. Finally, management and design questions about the warm water aquaculture ponds, such as the pond temperature throughout an average weather year, the amount of energy needed to maintain the pond temperature constant and the amount of energy required to warm a pond from 10 to 28°C, were answered by additional simulations.
Exergetic performance analysis of a recirculating aquaculture system
Energy Conversion and Management, 2010
This paper examines exergetic aspects of a Recirculation Aquaculture System (RAS) for Black Sea trout (Salmo trutta labrax) fingerling rearing at the Trabzon Central Fisheries Research Institute, Turkey. In its thermodynamic analysis, each component of the RAS is treated as a steady-state steady flow system and its exergetic efficiencies are studied. In addition, the following parameters are measured and recorded in experiments: the mass flow rates, inlet and outlet temperatures and of the system components, surrounding temperatures, and electrical work utilized by the components in the RAS. Based on these experimental data, inlet and outlet exergy values, exergy losses, and exergetic efficiencies of each component in the system are determined to assess their performance. Moreover, the overall system exergy efficiency is determined. The results show that exergy efficiencies of the system components are highly affected by varying input exergy flows as a function of the surrounding temperature and chiller's operating period.
Current Journal of Applied Science and Technology
Recirculating aquaculture systems have proven very successful in resolving problems relating to water shortages for fish production and increased yield as the stocking density is important. These systems however consumed much energy in running pumps and heating of water since temperatures play a critical role in fish growth. The main objective of this study is to contribute in putting in place a stable automatic temperature-controlled recirculating aquaculture system capable of using water and energy in an efficient manner. The aim is to develop a system that can use 1000 L of water and grow fish to maturity. The system consisted of a 1000 L capacity tank, a mechanical filter, a bio rock filter, a de-nitrification tank with water hyacinth, an aeration system, a 12 V solar pump, a solar water heating system, and computerized automatic controls using the Arduino microprocessor. Everything was powered by 100 Watts solar module connected through a charge controller to a 200 AH Battery. ...