scholarly journals Design of a 35 kW Solar Cooling Demonstration Facility for a Hotel in Spain

2020 ◽  
Vol 10 (2) ◽  
pp. 496 ◽  
Author(s):  
Pedro J. Martínez ◽  
Pedro Martínez ◽  
Victor M. Soto ◽  
Luis A. Bujedo ◽  
Juan Rodriguez
Keyword(s):  
Cooling System ◽  
Cooling Capacity ◽  
Point Of View ◽  
Hot Water ◽  
Design Decision ◽  
Specific Storage ◽  
Economic Point ◽  
Water Storage Tank ◽  
Solar Cooling ◽  
The Hours

Solar cooling systems have the advantage of the coincidence between the hours of cooling demand and the hours of solar radiation availability, and they can contribute to reduce the energy consumption in buildings. However, the high cost of thermal solar cooling facilities with absorption chillers, maintenance issues, legionella risk and water consumption (associated to the necessary cooling tower) have limited the use of these systems to demonstration projects. A simplified Transient System Simulation Tool (TRNSYS) model was developed to provide the owner of the demonstration facility the information he needs for design decision-making. This model was validated with experimental data registered in a solar cooling system designed and built by the authors. Different collector field surfaces, hot water storage tank volumes, and absorption machine driving temperatures were analyzed for a hotel demonstration facility. In terms of the energy delivered to the absorption chiller the optimum dimensioning corresponded to the lowest values of the driving temperature (75 °C) and specific storage volume (15 Lm2). From an economic point of view, the saving of 1515 euros per year when compared with an electric compression chiller does not compensate the investment of 3000 euros per kW of cooling capacity that cost the thermal solar cooling facility.

scholarly journals Installation and Operation of a Solar Cooling and Heating System Incorporated with Air-Source Heat Pumps

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 996 ◽  
Author(s):  
Li Huang ◽  
Rongyue Zheng ◽  
Udo Piontek
Keyword(s):  
Heating System ◽  
Cooling Capacity ◽  
Heat Pumps ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Energy Yield ◽  
Absorption Chiller ◽  
Annual Average ◽  
Water Storage Tank ◽  
Solar Cooling

A solar cooling and heating system incorporated with two air-source heat pumps was installed in Ningbo City, China and has been operating since 2018. It is composed of 40 evacuated tube modules with a total aperture area of 120 m2, a single-stage and LiBr–water-based absorption chiller with a cooling capacity of 35 kW, a cooling tower, a hot water storage tank, a buffer tank, and two air-source heat pumps, each with a rated cooling capacity of 23.8 kW and heating capacity of 33 kW as the auxiliary system. This paper presents the operational results and performance evaluation of the system during the summer cooling and winter heatingperiod, as well as on a typical summer day in 2018. It was found that the collector field yield and cooling energy yield increased by more than 40% when the solar cooling and heating system is incorporated with heat pumps. The annual average collector efficiency was 44% for cooling and 42% for heating, and the average coefficient of performance (COP) of the absorption chiller ranged between 0.68 and 0.76. The annual average solar fraction reached 56.6% for cooling and 62.5% for heating respectively. The yearly electricity savings accounted for 41.1% of the total electricity consumption for building cooling and heating.

Experimental Analysis of Newly Designed Solar Assisted Single Effect Absorption Cooling System of 5.25 kW Cooling Capacity for Domestic Use

2015 ◽  
Vol 787 ◽  
pp. 32-36 ◽  
Author(s):  
V.Boopathi Raja ◽  
V. Shanmugam
Keyword(s):  
Cooling System ◽  
Cooling Capacity ◽  
Hot Water ◽  
Operational Parameters ◽  
Water Storage Tank ◽  
Absorption Cooling ◽  
Domestic Use ◽  
Single Effect ◽  
Absorption Cooling System ◽  
Vapour Compression

Many research studies have been carried out to develop small capacity absorption cooling systems as an alternative to conventional vapour compression refrigeration (VCR) systems with respect to performance and economic aspects. The aim of this work is to design a solar assisted single effect absorption cooling system of 5.25 kW cooling capacity to cool a room having floor area of 15 m2. Based on the design, an experimental setup is constructed and operated by supplying heat to the generator using solar energy. The performance analysis of the cooling system is carried out by measuring the various operational parameters. The minimum cooling temperature of 16°C is observed in the evaporator and maximum COP of 0.9 is obtained when the hot water storage tank reaches 90°C. As per this new design, the operational cost is minimized and the COP obtained is slightly higher when compared to that of earlier similar works.

Simulation and Experimental Analysis of a Solar Driven Absorption Chiller With Partially Wetted Evaporator

2008 ◽  
Author(s):  
Jan Albers ◽  
Giovanni Nurzia ◽  
Felix Ziegler
Keyword(s):  
Cooling System ◽  
Cooling Water ◽  
Hot Water ◽  
Absorption Chiller ◽  
Efficient Operation ◽  
Part Load ◽  
Solar Cooling ◽  
Wetted Area ◽  
Solar Cooling System ◽  
Load Conditions

The efficient operation of a solar cooling system strongly depends on the chiller behaviour under part-load conditions since driving energy and cooling load are never constant. For this reason the performance of a single stage, hot water driven 30 kW H2O/LiBr-absorption chiller employed in a solar cooling system with a field of 350 m2 evacuated tube collectors has been analysed under part-load conditions with both simulations and experiments. A simulation model has been developed for the whole absorption chiller (Type Yazaki WFC-10), where all internal mass and energy balances are solved. The connection to the external heat reservoirs of hot, chilled and cooling water is done by lumped and distributed UA-values for the main heat exchangers. In addition to an analytical evaporator model — which is described in detail — experimental correlations for UA-values have been used for condenser, generator and solution heat exchanger. For the absorber a basic model based on Nusselt theory has been employed. The evaporator model was developed taking into account the distribution of refrigerant on the tube bundle as well as the change in operation from a partially dry to an overflowing evaporator. A linear model is derived to calculate the wetted area. The influence of these effects on cooling capacity and COP is calculated for three different combinations of hot and cooling water temperature. The comparison to experimental data shows a good agreement in the various operational modes of the evaporator. The model is able to predict the transition from partially dry to an overflowing evaporator quite well. The present deviations in the domain with high refrigerant overflow can be attributed to the simple absorber model and the linear wetted area model. Nevertheless the results of this investigation can be used to improve control strategies for new and existing solar cooling systems.

scholarly journals Experimental Performance Evaluation of an Integrated Solar-Driven Adsorption System in Terms of Thermal Storage and Cooling Capacity

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5931
Author(s):  
M.T. Nitsas ◽  
E.G. Papoutsis ◽  
I.P. Koronaki
Keyword(s):  
Energy Production ◽  
Cooling System ◽  
Thermal Storage ◽  
Cooling Capacity ◽  
Climatic Conditions ◽  
Environmentally Benign ◽  
Heat Sources ◽  
Adsorption Chiller ◽  
Solar Cooling ◽  
Dual Bed

Heat-driven coolers provide a reliable and environmentally benign alternative to traditional electrically powered chillers. Their main advantage is that they can be driven using low enthalpy heat sources. A solar system is installed at the school of Mechanical Engineering of National Technical University of Athens in order to examine the potential of thermal storage and solar cooling under Athens climatic conditions. The cooling effect is produced using a dual bed, single stage, zeolite/water adsorption chiller with cooling capacity of 10 kW at its nominal conditions of operation. Both vacuum tube collectors and hybrid photovoltaic thermal collectors are installed in order to supply the system with heat. The system is evaluated in terms of solar collectors’ useful energy production, heat stored in the intermediate buffer and cooling system’s performance. It is observed that the cooling system operates satisfactorily under Athens climatic conditions achieving a maximum cooling capacity of 3.7 kW and an average COP around 0.5.

Design and Modeling of One Refrigeration Ton Solar Assisted Adsorption Air Conditioning System

2014 ◽  
Vol 137 (1) ◽  
Author(s):  
M. Alkhair ◽  
M. Y. Sulaiman ◽  
K. Sopian ◽  
C. H. Lim ◽  
E. Salleh ◽  
...  
Keyword(s):  
Air Conditioning ◽  
Cooling Water ◽  
Cooling Capacity ◽  
Hot Water ◽  
Activated Carbon Fiber ◽  
Coefficient Of Performance ◽  
Weather Data ◽  
Adsorption System ◽  
Water Storage Tank ◽  
Chilled Water

The modeling of the performance of a one refrigeration ton (RT) solar assisted adsorption air-conditioning refrigeration system using activated carbon fiber/ethanol as the adsorbent/adsorbate pair has been undertaken in this study. The effects of hot water, cooling water, chilled water inlet temperatures, and hot water and chilled water flow rates were taken into consideration in the optimization of the system and in the design of the condenser, evaporator, and hot water storage tank. The study includes analysis of the weather data and its effect on both the adsorption system and the cooling load. This is then followed by estimation of the cooling capacity and coefficient of performance (COP) of the adsorption system as a function of the input parameters. The results of the model will be compared to experimental data in a next step.

TRNSYS Modeling of a Linear Fresnel Concentrating Collector for Solar Cooling and Hot Water Applications

2015 ◽  
Vol 137 (2) ◽  
Author(s):  
Tanzeen Sultana ◽  
Graham L. Morrison ◽  
Robert Taylor ◽  
Gary Rosengarten
Keyword(s):  
Cfd Simulation ◽  
Cooling System ◽  
Hot Water ◽  
Water Usage ◽  
Optical Efficiency ◽  
Solar Cooling ◽  
Computational Fluid Dynamics Cfd ◽  
Trnsys Modeling ◽  
Transient System ◽  
Solar Cooling System

In this paper, simulation of a linear Fresnel rooftop mounted concentrating solar collector is presented. The system is modeled with the transient system (trnsys) simulation program using the typical meteorological year file containing the weather parameters of four different cities in Australia. Computational fluid dynamics (CFD) was used to determine the heat transfer mechanism in the microconcentrating (MCT) collector. Ray trace simulations using soltrace (NREL) were used to determine optical efficiency. Heat loss characteristics determined from CFD simulation were utilized in trnsys to assess the annual performance of the solar cooling system using an MCT collector. The effect of the different loads on the system performance was investigated, and from trnsys simulations, we found that the MCT collector achieves a minimum 60% energy saving for both domestic hot water usage and high temperature solar cooling and hot water applications.

scholarly journals The Design and Installation of a Combined Concentrating Power Station, Solar Cooling System and Domestic Hot Water System

2015 ◽  
Vol 70 ◽  
pp. 486-494 ◽  
Author(s):  
Jeremy P. Osborne ◽  
Paul Kohlenbach ◽  
Uli Jakob ◽  
Johan Dreyer ◽  
Jamey Kim
Keyword(s):  
Cooling System ◽  
Water System ◽  
Hot Water ◽  
Power Station ◽  
Domestic Hot Water ◽  
Solar Cooling ◽  
Solar Cooling System

Simulation and Experimental Analysis of a Solar Driven Absorption Chiller With Partially Wetted Evaporator

2010 ◽  
Vol 132 (1) ◽  
Author(s):  
Jan Albers ◽  
Giovanni Nurzia ◽  
Felix Ziegler
Keyword(s):  
Cooling System ◽  
Cooling Water ◽  
Hot Water ◽  
Absorption Chiller ◽  
Efficient Operation ◽  
Part Load ◽  
Solar Cooling ◽  
Wetted Area ◽  
Solar Cooling System ◽  
Load Conditions

The efficient operation of a solar cooling system strongly depends on the chiller behavior under part load conditions, since driving energy and cooling load are never constant. For this reason, the performance of a single stage, hot water driven 30 kW H2O/LiBr-absorption chiller employed in a solar cooling system with a field of 350 m2 evacuated tube collector has been analyzed under part load conditions with both simulations and experiments. A simulation model has been developed for the whole absorption chiller (Type Yazaki WFC-10), where all internal mass and energy balances are solved. The connection to the external heat reservoirs of hot, chilled, and cooling water is done by lumped and distributed UA values for the main heat exchangers. In addition to an analytical evaporator model—which is described in detail—experimental correlations for UA values have been used for the condenser, generator, and solution heat exchanger. For the absorber, a basic model based on the Nusselt theory has been employed. The evaporator model was developed, taking into account the distribution of refrigerant on the tube bundle, as well as the change in operation from a partially dry to an overflowing evaporator. A linear model is derived to calculate the wetted area. The influence of these effects on cooling capacity and coefficient of performance (COP) is calculated for three different combinations of hot and cooling water temperature. The comparison to experimental data shows a good agreement in the various operational modes of the evaporator. The model is able to predict the transition from partially dry to an overflowing evaporator quite well. The present deviations in the domain with high refrigerant overflow can be attributed to the simple absorber model and the linear wetted area model. Nevertheless, the results of this investigation can be used to improve control strategies for new and existing solar cooling systems.

Performance of a Solar Desiccant Cooling System

1988 ◽  
Vol 110 (3) ◽  
pp. 165-171 ◽  
Author(s):  
George O. G. Lo¨f ◽  
Gerald Cler ◽  
Thomas Brisbane
Keyword(s):  
Heat Exchange ◽  
Solar Energy ◽  
Cooling System ◽  
Evaporative Cooling ◽  
Hot Water ◽  
Colorado State University ◽  
Energy Applications ◽  
Solar Cooling ◽  
Cooling Unit ◽  
Electric Boiler

A solar desiccant cooling system was operated at the Solar Energy Applications Laboratory, Colorado State University, throughout the 1986 summer. The system comprises an American Solar King fresh air heating/desiccant evaporative cooling unit, a Sunmaster evacuated tube solar collector, hot water solar storage tank, auxiliary electric boiler, controls, and accessories. The cooling unit is operated in the ventilation mode, fresh air being dried in a rotating desiccant matrix, and cooled by heat exchange and evaporative cooling. Return air is used as a cooling medium in a rotating heat exchange matrix, heated by solar energy in a heat exchange coil, and discarded through the rotating desiccant bed. The solar-driven system provided over 90 percent of the seasonal cooling requirements in an experimental, residence type building at average COP levels of 1.0 and solar collection efficiencies of 50 percent when supplied with solar heated water at temperatures of 50 to 65° C. Detailed operating results, including total and average solar cooling provided, coefficients of performance, and overall solar cooling performance ratios are presented.

scholarly journals Design of a modified natural egyptian solar house

2020 ◽  
Vol 10 (1) ◽  
pp. 589
Author(s):  
Hanaa M. Farghally ◽  
Faten H. Fahmy ◽  
Amal A. Hassan ◽  
Ninet M. Ahmed
Keyword(s):  
Cooling System ◽  
Residential Buildings ◽  
Cost Effective ◽  
Heating System ◽  
Hot Water ◽  
Storage Unit ◽  
Water Storage Tank ◽  
Rate Of Increase ◽  
Almost All ◽  
Solar House

The rate of increase in energy consumption and high costs in addition to the depletion of existing resources has a significant impact on our standard of living for next generations. In this case, the priority is to develop alternative cost-effective sources for powering the residential and non-residential buildings. This paper proposes and develops a design of a modified small two-story residential solar house for a medium-sized family located in Cairo, Egypt. This modified solar house meets almost all its energy demands including space heating by using solar air collector with a pebble storage unit in winter and a summer cooling system using wind catcher theory. Hot water is obtained throughout the day by using a steel sheltered water storage tank with a capacity of 1000 liter. Finally, the proposed heating system of the solar house is sized and modeled.

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