Energy, Exergy and Economic Analysis of Absorption Chiller Systems: A Case Study for a Wood Pencil Factory

2021 ◽  
pp. 1469-1477

This study examines the use of absorption chiller systems in a designated industrial facility having waste heat by conducting energy, exergy and economic analyses. The absorption chiller systems namely single-effect, double-effect series, double-effect parallel and double-effect reverse parallel were analysed to determine the best alternative for the wood pencil factory. The results indicated that the COP of the single-effect absorption chiller systems is changed from 0.758 to 0.763 when the temperature of the generator was increased from 89 ºC to 125 ºC. However, the exergetic performance of the single-effect absorption chiller system decreased by 40% in the same generator temperature range. On the other hand, COP of all double-effect absorption chiller systems increased about 8 % when the generator temperature was changed from 116 ºC to 155 ºC while the exergetic performance of all double absorption chiller systems decreased by around 14% for the same generator temperature range. The COP and exergetic efficiency values of the double-effect parallel system were found to be higher than other absorption systems at all generator temperature values. Overall, this study recommends that the double-effect parallel absorption chiller systems can be preferred for the factories having waste heat source wood chips. The average payback period of the system was also found to be 1.4 years. Furthermore, this study shows that double-effect parallel absorption chiller systems can be proposed for the facilities having wood chips waste sources instead of double-effect reverse parallel absorption chiller systems since they are easy to operate and have lower maintenance costs.

This study examines the use of absorption chiller systems in a designated industrial facility having waste heat by conducting energy, exergy and economic analyses. The absorption chiller systems namely single-effect, double-effect series, double-effect parallel and double-effect reverse parallel were analysed to determine the best alternative for the wood pencil factory. The results indicated that the COP of the single-effect absorption chiller systems is changed from 0.758 to 0.763 when the temperature of the generator was increased from 89 ºC to 125 ºC. However, the exergetic performance of the single-effect absorption chiller system decreased by 40% in the same generator temperature range. On the other hand, COP of all double-effect absorption chiller systems increased about 8 % when the generator temperature was changed from 116 ºC to 155 ºC while the exergetic performance of all double absorption chiller systems decreased by around 14% for the same generator temperature range. The COP and exergetic efficiency values of the double-effect parallel system were found to be higher than other absorption systems at all generator temperature values. Overall, this study recommends that the double-effect parallel absorption chiller systems can be preferred for the factories having waste heat source wood chips. The average payback period of the system was also found to be 1.4 years. Furthermore, this study shows that double-effect parallel absorption chiller systems can be proposed for the facilities having wood chips waste sources instead of double-effect reverse parallel absorption chiller systems since they are easy to operate and have lower maintenance costs.


This study examines the use of absorption chiller systems in a designated industrial facility having waste heat by conducting energy, exergy and economic analyses. The absorption chiller systems namely single-effect, double-effect series, double-effect parallel and double-effect reverse parallel were analysed to determine the best alternative for the wood pencil factory. The results indicated that the COP of the single-effect absorption chiller systems is changed from 0.758 to 0.763 when the temperature of the generator was increased from 89 ºC to 125 ºC. However, the exergetic performance of the single-effect absorption chiller system decreased by 40% in the same generator temperature range. On the other hand, COP of all double-effect absorption chiller systems increased about 8 % when the generator temperature was changed from 116 ºC to 155 ºC while the exergetic performance of all double absorption chiller systems decreased by around 14% for the same generator temperature range. The COP and exergetic efficiency values of the double-effect parallel system were found to be higher than other absorption systems at all generator temperature values. Overall, this study recommends that the double-effect parallel absorption chiller systems can be preferred for the factories having waste heat source wood chips. The average payback period of the system was also found to be 1.4 years. Furthermore, this study shows that double-effect parallel absorption chiller systems can be proposed for the facilities having wood chips waste sources instead of double-effect reverse parallel absorption chiller systems since they are easy to operate and have lower maintenance costs.


2018 ◽  
Vol 22 (5) ◽  
pp. 2151-2162
Author(s):  
Jose Marcos ◽  
Raquel Lizarte ◽  
Fernando Varela ◽  
Maria Palacios-Lorenzo ◽  
Ana Blanco-Marigorta

A solar cooling system with an optimized air-cooled double-effect water/LiBr absorption machine is proposed as a sustainable alternative to meet cooling demands in dry hot climates. This system allows eliminating the cooling towers in those regions of the planet where water is scarce. This work analyses the environmental benefits of this air-cooled system, as well as its environmental foot-prints, compared to a solar water-cooled single effect. In this regard, a methodology has been applied to calculate the annual saving in water consumption produced in a case study: a hospital located in Almer?a, in South of Spain. Further-more, the reduction in energy consumption and CO2 emissions is also quantified since this machine can be driven by solar energy and with higher efficiency than those of single effect.


2021 ◽  
pp. 1-29
Author(s):  
Ali Alsagri

Abstract The experience of leading countries in distributed energy systems (e.g., Scandinavian countries) shows that district cooling systems are highly beneficial techno-economic-environmentally by facilitating the use of waste heat resources, solar energy, etc., for cold supply at large scales. This study proposes the optimal development of a novel district cooling design utilizing the exhaust waste heat of an energy plant in a case study in Saudi Arabia. The optimal configuration of the hybrid system, the sizing of its components, and operating conditions of them are found using multiobjective optimization techniques based on the genetic algorithm method and a creative performance assessment index. Then, the feasibility of this optimized proposal is investigated through comprehensive thermodynamic and economic analyses. The results show that a district cooling system can surely cope with the harsh climate condition of the case study and provide the required interior comfort conditions. The energy and exergy efficiencies of the system can be as high as 62% and 53% using an absorption chiller utilizing a power plant's waste heat along with a storage tank for peak shaving. The levelized cost of cooling of the system can be 28 USD/MWh, by which the payback period will be only 8 years.


Author(s):  
Timothy C. Wagner ◽  
Lynn Rog ◽  
Sung-Han Jung

The objective of this investigation was the development and testing of a waste heat-driven chiller capable of simultaneously generating chilled and heated water. In addition to simultaneous operation, the ability to seamlessly change from chilling to heating eliminates the seasonal changeover which is typical in existing absorbers. These enhancements significantly increase the flexibility and utilization of the chiller. In this paper, the design of the chiller will be described along with presentation of results from testing of a 140 RT full-scale prototype chiller. A case study for a hospital in New Jersey will also be presented to show the additional energy utilization provided by the simultaneous capability.


2010 ◽  
Vol 18 (01) ◽  
pp. 23-29
Author(s):  
CHAN WOO PARK ◽  
DA YOUNG YOU ◽  
HYOUNG JIN KIM ◽  
IK-TAE IM

In this study, the characteristics of the hybrid type absorption chiller, combined with the single effect absorption chiller and the double effect absorption chiller, are numerically studied to use waste hot water effectively. In the case of the full load for hybrid type absorption system, the concentration and temperature of LiBr solution increase about 2.2°C and 0.7%, respectively, at the single effect generator by the hot water. As the partial load decreases, the COP decreasing ratio of the hybrid type absorption chiller is higher than that of the double effect absorption chiller. On the other hand, COP f shows the opposite result of COP. The cycle COP of the hybrid type is about 1.07 on the full load which is 0.11 lower than that of the conventional double effect type. But COP f of the hybrid type is 1.28 which is 0.22 larger than that of double effect type. In the case of 50% partial load, COP f of the hybrid type is 2.66 and at below 50% partial load, system can be operated without any fuels. As the temperature of hot water and the mass flow ratio of hot water increase, the fuel saving ratio increases. The effect of the inlet temperature on the COP and COP f is much more significant than that of the mass flow rate of the hot water.


Solar Energy ◽  
2002 ◽  
Author(s):  
James B. Bergquam ◽  
Joseph M. Brezner

This paper presents the results of a thermodynamic and heat transfer analysis of solar fired, compressor assisted absorption chillers. The objectives are to determine and evaluate the feasibility of using vapor compressors to lower the operating temperature of the primary generator, simplify the maintenance and reduce the cost of solar/waste heat powered absorption HVAC systems. The nominal generator temperature in a single effect absorption chiller is 88°C and the coefficient of performance is approximately 0.8. A standard double effect chiller requires the high temperature generator to operate at about 150°C. The nominal COP of a double effect cycle is 1.2 to 1.4. Various modifications have been proposed to lower the operating temperature of the primary generator. One such modification is to add a vapor compressor to the basic cycle. Computer models that simulate the effect of vapor compressors at selected locations in single and double effect LiBr/H2O absorption chillers have been developed. Two locations were modeled for single effect chillers and three locations for double effect chillers. The best results were obtained for a double effect chiller with the compressor located between the high and low temperature generators.


Author(s):  
Mamdouh El Haj Assad ◽  
Milad Sadeghzadeh ◽  
Mohammad Hossein Ahmadi ◽  
Mohammad Al‐Shabi ◽  
Mona Albawab ◽  
...  

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