A novel solar thermal polygeneration system for sustainable production of cooling, clean water and domestic hot water in United Arab Emirates: Dynamic simulation and economic evaluation

2016 ◽  
Vol 167 ◽  
pp. 173-188 ◽  
Author(s):  
Gowtham Mohan ◽  
Uday Kumar ◽  
Manoj Kumar Pokhrel ◽  
Andrew Martin
2015 ◽  
Vol 82 ◽  
pp. 630-636 ◽  
Author(s):  
Matteo Dongellini ◽  
Stefania Falcioni ◽  
Gian Luca Morini

In this paper, a novel solar thermal cogeneration (termed as solar combi MD; SCMD) system for production of clean water and domestic hot water is modeled and analyzed for the weather conditions of United Arab Emirates (UAE). The system comprises of solar collectors for production of thermal energy, thermal storage for domestic hot water generation and membrane distillation (MD) modules for clean water production gaining energy through a plate heat exchanger. The performance of cogeneration is analyzed with two different solar collectors used for domestic heating – flat plate collectors (FPC) and evacuated tube collector (ETC). The system is modeled and dynamically simulated using TRNSYS software for optimization of various design parameters like collectors tilt angle, mass flow rate through MD loop, thermal store volume and heat exchanger effectiveness. Cogeneration system efficiencies and collector areas has been determined for optimum conditions. Economic benefits are analyzed for FPC collectors and fuel costs savings compared to individual system operation. Total investment cost of SCMD system for single family application would be around 5000$ with an impressive payback period of 5.5 years which is 30% lower than regular SDHW installations.


Author(s):  
Radu Radoi ◽  
Ioan Pavel ◽  
Corneliu Cristescu ◽  
Liliana Dumitrescu

Fossil fuels are an exhaustible resource on Earth, and their use pollutes the environment massively. The population of the planet has grown a lot, and for the production of domestic hot water, to ensure a decent standard of living, it is necessary to consume increasing quantities of fossil fuels. The very high level of greenhouse gases released into the atmosphere leads to an increase in average of annual temperature and climate change. Climate change is manifested by the melting of the ice caps, which has the consequence of increasing the level of the seas and oceans. Climate change also leads to extreme weather events such as floods, heat waves or the appearance of arid areas. Risks to human health have increased through deaths caused by heat or by changing the way some diseases are spread. Risks also exist for flora and wildlife due to rapid climate change.Many species of animals migrate, and other species of animals and plants are likely to disappear. Climate change also leads to costs for society and the economy due to damage to property and infrastructure, which have been more than 90 billion euros in the last 30 years, just because of the floods. In order to reduce the effects of environmental pollution, ecological energy production solutions need to be expanded. The article presents the creation of an experimental stand of a Solar - TLUD stove combined system for the production of domestic hot water in a sustainable way. TLUD is the acronym for "Top-Lit UpDraft". The advantage of the combined heat system is that it can provide thermal energy both during the day and at night. If the atmospheric conditions are unfavorable (clouds, fog) and do not allow the water to be heated only with the solar panel, TLUD gas stove can be used to supplement the energy. The TLUD stove has low Carbon Monoxide (CO) and Particulate Matter (PM) emissions. After gasification, about 10% of the carbon contained in the biomass is thermally stabilized and can be used as a "biochar" in agriculture or it can be burnt completely, resulting in very little ash. The stand is composed of a solar thermal panel, a TLUD stove, a boiler for hot water storage and an automation system with circulation pumps and temperature sensors. To record the experimental results, a data acquisition board was used, with which data were recorded from a series of temperature and flow transducers located in the installation. Experimental results include diagrams for temperature variation, available energy and heat accumulated in the boiler. Keywords: combined thermal system, TLUD stove, domestic hot water, solar thermal panel, data aquisition system


Author(s):  
Gonzalo Sánchez-Barroso ◽  
Jaime González-Domínguez ◽  
Justo García-Sanz-Calcedo

Hospitals need to prepare large amounts of domestic hot water (DHW) to develop their healthcare activity. The aim of this work was to analyse potential savings that can be achieved by installing solar thermal energy for production of domestic hot water in the hospitals of Extremadura (Spain). For this purpose, 25 hospitals between 533 and 87,118 m2 and between 15 and 529 beds were studied, three solar factor scenarios were simulated (0.70, 0.75 and 0.80) and the necessary investment and corresponding economic and environmental savings were calculated. Better economic results and energy ratios for 70% of solar contribution were obtained. These results show an average payback of 4.74 years (SD = 0.26) reaching 4.29 kWh/€ per year (SD = 0.20). Undertaking an investment of 674,423 €, 2,895,416 kWh/year of thermal energy could be generated with which to save both 145,933 € and 638 tons of CO2 per year. It was statistically demonstrated the priority of carrying out an installation with a solar factor of 70%, investing preferably in hospitals in Cáceres over those in Badajoz, especially in the public sector with more than 300 beds. These findings will provide hospital managers with useful information to make decisions on future investments.


2012 ◽  
Vol 97 ◽  
pp. 897-906 ◽  
Author(s):  
M.C. Rodríguez-Hidalgo ◽  
P.A. Rodríguez-Aumente ◽  
A. Lecuona ◽  
M. Legrand ◽  
R. Ventas

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4603
Author(s):  
Francesca Ceglia ◽  
Adriano Macaluso ◽  
Elisa Marrasso ◽  
Carlo Roselli ◽  
Laura Vanoli

This paper presents a thermodynamic, economic, and environmental analysis of a renewable polygeneration system connected to a district heating and cooling network. The system, fed by geothermal energy, provides thermal energy for heating and cooling, and domestic hot water for a residential district located in the metropolitan city of Naples (South of Italy). The produced electricity is partly used for auxiliaries of the thermal district and partly sold to the power grid. A calibration control strategy was implemented by considering manufacturer data matching the appropriate operating temperature levels in each component. The cooling and thermal demands of the connected users were calculated using suitable building dynamic simulation models. An energy network dedicated to heating and cooling loads was designed and simulated by considering the variable ground temperature throughout the year, as well as the accurate heat transfer coefficients and pressure losses of the network pipes. The results were based on a 1-year dynamic simulation and were analyzed on a daily, monthly, and yearly basis. The performance was evaluated by means of the main economic and environmental aspects. Two parametric analyses were performed by varying geothermal well depth, to consider the uncertainty in the geofluid temperature as a function of the depth, and by varying the time of operation of the district heating and cooling network. Additionally, the economic analysis was performed by considering two different scenarios with and without feed-in tariffs. Based on the assumptions made, the system is economically feasible only if feed-in tariffs are considered: the minimum Simple Pay Back period is 7.00 years, corresponding to a Discounted Pay Back period of 8.84 years, and the maximum Net Present Value is 6.11 M€, corresponding to a Profit Index of 77.9% and a maximum Internal Rate of Return of 13.0%. The system allows avoiding exploitation of 27.2 GWh of primary energy yearly, corresponding to 5.49∙103 tons of CO2 avoided emissions. The increase of the time of the operation increases the economic profitability.


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