Thermal Modeling of a Greenhouse Fish Pond System (original) (raw)

1 Thermal Modeling of a Greenhouse Fish Pond System

2005

A thermal model has been developed for heating the aquaculture pond by even span greenhouse. Numerical computations have been performed for a typical day in the month of January, 2005 for the composite climate of New Delhi. The energy balance equations have been written considering the effects of conduction, convection, radiation, evaporation and ventilation, etc. The model has been validated with the experimental data. From the results, it was observed that the predicted values of room temperature and water temperature in the tanks of the greenhouse obtained from the proposed model exhibited fair agreement with the experimental values.

Thermal modeling and parametric studies of a greenhouse fish pond in the Central Himalayan Region

Energy Conversion and Management, 2006

This study describes the thermal modeling and its validation of greenhouse fish pond systems. Numerical computations have been performed for a typical day in the month of June, 2005, for the climatic condition of Champawat in the Central Himalayan Region. The energy balance equations have been written considering the effects of conduction, convection, radiation, evaporation and ventilation. The governing equations are numerically solved with Matlab 7.0 software to predict the water temperature. A parametric study has also been performed to find the effects of various parameters, namely the number of air changes per hour, the transmissivity (s) and the isothermal mass and height of the greenhouse. It is observed that there is no significant effect in the parametric studies on water temperature due to the larger isothermal mass. The model has been validated with experimental data. On an average, the even span passive greenhouse fish pond can increase the inside temperature 4.14°C higher than the temperature of an outdoor pond. Statistical analysis shows that the predicted and experimental values of water temperature exhibited fair agreement with a coefficient of correlation r = 0.90 and root mean square percent deviation e = 1.67%.

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.

Study of thermal aspects in open and greenhouse ponds

International Journal of Energy Research, 2006

In this study, thermal aspects, e.g. convective heat transfer coefficients were evaluated and modelled in open and greenhouse pond systems (natural convection). Values of the constants C and n were determined by linear regression analysis from the experimental data. It was observed that the ranges of the convective heat transfer coefficient were strongly dependent upon D/H (Diameter / Height) ratio of the container. It was also observed that the uninsulated container 5 (D=H ¼ 5:240) and the insulated container 1 (D=H ¼ 0:196) indicate minimum and maximum convective heat transfer coefficient in winter and summer months, respectively. Predicted and experimental values of convective heat transfer coefficients, verified in terms of root mean square of percent deviation, correlation coefficient and error bars (AE SD), exhibit fair agreement. The model has been validated for the composite climate of New Delhi.

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.

SIMULATION MODEL FOR AQUACULTURE POND HEAT BALANCE: II MODEL EVALUATION AND APPLICATION

The performance of a model developed by Ali (2006) to simulate aquaculture pond temperature was evaluated using sensitivity analysis and the model verified with data from aquaculture pond. The sensitivity analysis showed that output varied linearly with changes in average air temperature and solar radiation. Results from model verification runs showed that the model performance was satisfactory with respect to aquaculture pond temperature. In the future, the model will be used to investigate the effects of aquaculture pond temperature on daily growth rate to obtain the weight of individual fish throughout the year

Thermal performance of different pond cells under actual climatic conditions in Qatar

Renewable Energy, 1999

Experimental work was undertaken to study the thermal performance of three different pond cells under actual climatic conditions of Qatar. The first cell was an open pond. In the second unit, a tinned radiator, painted Ma&, was placed over the pond. In the third cell, the water was contained in a polyethylene hag Experimental results indicated that the exposed pond cell came out best. when considered in terms of how quickly the temperature of the stored water could he reduced, and how low that temperature could be. The water in the exposed pond was cooled directly (by evaporation and radiation to sky) whereas in the case of the finned radiator cell, heat had to be transferred from the stored water to the radiator, and then from the radiator to the surrounding. In the case of water-in-hag cell, evaporation was eliminated and radiative exchange with the sky was reduced due to the partial transparency of the polyethylene hag (in the infrared region).

Performance Study of a Floricultural Greenhouse Surrounded by Shallow Water Ponds

International Journal of Renewable Energy Development

In the present paper, an innovative low energy-intensive evaporative cooling system has been proposed for greenhouse application in near-tropical regions dominated by hot climate. The system can operate under dual- ventilation mode to maintain a favourable microclimate inside the greenhouse. A single ridge type un-even span greenhouse has been considered, targeting a few species of Indian tropical flowers. The greenhouse has a continuous roof vent as well as adjustable side vents and is equipped with exhaust fans on top and roll-up curtains on the sides. The greenhouse is surrounded by shallow water ponds outside its longitudinal walls and evaporative surfaces partially cover the free water surface. Inside the pond, low cost evaporative surfaces are so placed that they form air channels. Thus, outside air flows through the channels formed by the wetted surfaces over the water surface and undergoes evaporative cooling before entering the greenhouse. A simplified theoretical model ha...

Simulation of a low-cost method for solar-heating an aquaculture pond

Energy in Agriculture, 1981

A greenhouse computer model was used to predict the temperature change of a solarheated aquaculture pond that is insulated with a double layer of transparent plastic film suspended over the pond. The results showed that a 9 ° C rise in water temperature can be achieved in January in Phoenix, AZ. This implies that such covers could allow year-round aquaculture production in Phoenix and other southern U.S. areas. Furthermore, the economics of a covered nursery pond operation appear particularly attractive.