scholarly journals Thermo-Economic Comparisons of Environmentally Friendly Solar Assisted Absorption Air Conditioning Systems

2021 ◽  
Vol 11 (5) ◽  
pp. 2442
Author(s):  
Adil Al-Falahi ◽  
Falah Alobaid ◽  
Bernd Epple

Absorption refrigeration cycle is considered a vital option for thermal cooling processes. Designing new systems is needed to meet the increasing communities’ demands of space cooling. This should be given more attention especially with the increasing conventional fossil fuel energy costs and CO2 emission. This work presents the thermo-economic analysis to compare between different solar absorption cooling system configurations. The proposed system combines a solar field, flashing tank and absorption chiller: two types of absorption cycle H2O-LiBr and NH3-H2O have been compared to each other by parabolic trough collectors and evacuated tube collectors under the same operating conditions. A case study of 200 TR total cooling load is also presented. Results reveal that parabolic trough collector combined with H2O-LiBr (PTC/H2O-LiBr) gives lower design aspects and minimum rates of hourly costs (5.2 $/h) followed by ETC/H2O-LiBr configuration (5.6 $/h). H2O-LiBr gives lower thermo-economic product cost (0.14 $/GJ) compared to the NH3-H2O (0.16 $/GJ). The absorption refrigeration cycle coefficient of performance ranged between 0.5 and 0.9.

2006 ◽  
Vol 17 (3) ◽  
pp. 65-70 ◽  
Author(s):  
V Mittal ◽  
K S Kasana ◽  
N S Thakur

This paper presents modelling and simulation of a solar absorption cooling system. In this paper, the modelling of a solar-powered, single stage, absorption cooling system, using a flat plate collector and water–lithium bromide solution, is done. A computer program has been developed for the absorption system to simulate various cycle configurations with the help of various weather data for the village Bahal, District Bhiwani, Haryana, India. The effects of hot water inlet temperatures on the coefficient of performance (COP) and the surface area of the absorption cooling component are studied. The hot water inlet temperature is found to affect the surface area of some of the system components. Moreover the effect of the reference temperature which is the minimum allowable hot water inlet temperature on the fraction of total load met by non-purchased energy (FNP) and coefficient of performance (COP) is studied and it is found that high reference temperature increases the system COP and decreases the surface area of system components but lower reference temperature gives better results for FNP than high reference temperatures.


Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3198 ◽  
Author(s):  
Adil Al-Falahi ◽  
Falah Alobaid ◽  
Bernd Epple

Solar absorption cycles for air conditioning systems have recently attracted much attention. They have some important advantages that aid in reducing greenhouse gas emissions. In this work, design and thermo-economic analyses are presented in order to compare between two different collector types (parabolic trough and evacuated tube) by water–lithium bromide absorption systems, and to select the best operating conditions. Generally, the system consists of three major parts. The first part is the solar field for thermal power conversion. The second part is the intermediate cycle, which contains a flashing tank and pumping system. The third part is the water lithium bromide absorption chiller. A case study for a sports arena with 700–800 kW total cooling load is also presented. Results reveal that a parabolic trough collector combined with H2O–LiBr (PTC/H2O–LiBr) gives lower design aspects and minimum rates of hourly costs (USD 5.2/h), while ETC/H2O–LiBr configuration give USD 5.6/h. The H2O–LiBr thermo-economic product cost is USD 0.14/GJ. The cycle coefficient of performance COP was in the range of 0.5 to 0.9.


KnE Energy ◽  
2015 ◽  
Vol 2 (2) ◽  
pp. 22
Author(s):  
Andang Widiharto ◽  
Didit Setyo Pamuji ◽  
Atik Nurul Laila ◽  
Fiki Rahmatika Salis ◽  
Luthfi Zharif ◽  
...  

<p>Air conditioning (AC) is one of the most building’s energy consumer, included in building of Engineering Physisc’s Departement, Universitas Gadjah Mada (UGM). The declining of fossil fuel reserves and the increasing effects of global warming, forcing the world to switch to renewable energy sources. This paper discusses the design of solar absorption cooling system to replace conventional AC in seven lecture halls of Engineering Physic’s Departement, UGM. There are some steps that have been done to design the solar absorption cooling, i.e. do a study of the potential availability of solar energy, calculate the cooling loads, analyze the thermodynamic process of the system, determine the type of collector to be used and calculate area of solar collector needed. The thermal coefficient of performance (COP) of the system designed was about 0.84 which could use some types of flat plate solar collector with each area corresponding to each efficiency values. </p><p><strong>Keyword</strong> : Air conditioning; global warming; solar absorption cooling; solar collector</p>


2018 ◽  
Vol 8 (11) ◽  
pp. 2163 ◽  
Author(s):  
Yuridiana Galindo Luna ◽  
Wilfrido Gómez Franco ◽  
Ulises Dehesa Carrasco ◽  
Rosenberg Romero Domínguez ◽  
José Jiménez García

The present study reports the experimental results of a parabolic trough collector field and an absorption cooling system with a nominal capacity of 5 kW, which operates with the ammonia-lithium nitrate mixture. The parabolic trough collectors’ field consists of 15 collectors that are made of aluminum plate in the reflector surface and cooper in the absorber tube, with a total area of 38.4 m2. The absorption cooling system consists of 5 plate heat exchangers working as the main components. Parametric analyses were carried out to evaluate the performance of both systems under different operating conditions, in independent way. The results showed that the solar collectors’ field can provide up to 6.5 kW of useful heat to the absorption cooling system at temperatures up to 105 °C with thermal efficiencies up to 19.8% and exergy efficiencies up to 14.93, while the cooling system operated at generation temperatures from 85–95 °C and condensation temperatures between 20 and 28 °C, achieving external coefficients of performance up to 0.56, cooling temperatures as low as 6 °C, and exergy efficiencies up to 0.13. The highest value for the solar coefficient of performance reached 0.07.


Author(s):  
Mohammed Al-Odat

This paper presents a theoretical investigation to simulate the utilization of (PV/T) technology to drive an absorption refrigeration system that is used for air conditioning of a classroom under Jordan climate conditions. The absorption refrigeration cycle uses the hot water from the PV/T collector with an assisted electrical heater as a heat source in the generator. In addition to the capability to utilize the PV/T to supply the building by domestic hot water and electricity if no need to run the refrigeration cycle. This analysis was carried using excel program and theoretical equations for the system. It was found that (PV/T) technology is very useful for thermal applications with high efficiency. Also, absorption refrigeration cycle has a good coefficient of performance because it main ly depends on the thermal energy with low electrical energy consumption to run the pump. Moreover, this system has a short payback period, low energy consumption, low running cost, and minimum environmental impact. The results of this study show that the system needs about (84 m 2 PV/T collectors) to cover 16 tons cooling load.


2020 ◽  
Vol 10 (8) ◽  
pp. 2761
Author(s):  
María Venegas ◽  
Néstor García-Hernando ◽  
Alejandro Zacarías ◽  
Mercedes de Vega

In this work, the performance of a single effect absorption cooling system fed by solar thermal energy is evaluated. The absorption chiller includes a membrane-based microchannel desorber using three types of nanoparticles: Al2O3, CuO, or carbon nanotubes (CNT). Correlations available in the open literature to calculate the thermal conductivity of nanofluids are reviewed. Using experimental data for the water-lithium bromide solution (H2O-LiBr) with Al2O3 and CNT nanoparticles, the most appropriate correlation for thermal conductivity is selected. Nanofluid properties are evaluated using a concentration of nanoparticles of up to 5% in volume. The largest increase in the desorption rate (7.9%), with respect to using pure H2O-LiBr solution, is obtained using CNT nanoparticles and the maximum concentration of nanoparticles simulated. The performance of the chiller is evaluated and the daily solar coefficient of performance (SCOP) for the solar cooling facility is obtained. The best improvement with respect to the conventional system (without nanoparticles) represents an increase in the cooling effect of up to 6%. The maximum number of desorber modules recommended, always lower than 50, has been identified.


Entropy ◽  
2020 ◽  
Vol 22 (10) ◽  
pp. 1165
Author(s):  
Adil Al-Falahi ◽  
Falah Alobaid ◽  
Bernd Epple

The main objective of this paper is to simulate solar absorption cooling systems that use ammonia mixture as a working fluid to produce cooling. In this study, we have considered different configurations based on the ammonia–water (NH3–H2O) cooling cycle depending on the solar thermal technology: Evacuated tube collectors (ETC) and parabolic trough (PTC) solar collectors. To compare the configurations we have performed the energy, exergy, and economic analysis. The effect of heat source temperature on the critical parameters such as coefficient of performance (COP) and exegetic efficiency has been investigated for each configuration. Furthermore, the required optimum area and associated cost for each collector type have been determined. The methodology is applied in a specific case study for a sports arena with a 700~800 kW total cooling load. Results reveal that (PTC/NH3-H2O)configuration gives lower design aspects and minimum rates of hourly costs (USD 11.3/h) while (ETC/NH3-H2O) configuration (USD 12.16/h). (ETC/NH3-H2O) gives lower thermo-economic product cost (USD 0.14/GJ). The cycle coefficient of performance (COP) (of 0.5).


2019 ◽  
Vol 27 (04) ◽  
pp. 1950035 ◽  
Author(s):  
Nishant Modi ◽  
Bhargav Pandya ◽  
Javad Hosseinpour ◽  
Majid Amidpour

The current study assesses the thermo-economic performance of a H2O[Formula: see text][EMIM][DMP] (1-ethyl-3-methylimidazolium dimethyl phosphate) working fluid-based absorption machine coupled with various solar collectors to cater the cooling load to business building at Gandhinagar city, India. H2O[Formula: see text][EMIM][DMP] could be an alternative to conventional LiBr[Formula: see text]H2O working fluid pair of absorption machines as it can operate without problem of crystallization which is perquisite for the continuous operation of the system. A mathematical model is developed to simulate the proposed system with 10[Formula: see text]kW cooling capacity at 5∘C. The sensitivity assessment is carried out to find the effect of various parameters including heat source temperature on the coefficient of performance (COP) and exergetic efficiency for each collector case. The optimum SCOP of parabolic trough collector (PTC)-based system is 11.43% higher compared to ETC-based system, whereas the ETC-based system is 25.10% economical than the PTC-based system. Furthermore, payback period for ETC-based system is only one month higher than FPC-based system, which altogether exhibits the superiority of ETC-coupled H2O[Formula: see text][EMIM][DMP] absorption refrigeration system over FPC-based system.


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