scholarly journals Performance evaluation of an active solar cooling system utilizing low cost plastic collectors and an evaporatively-cooled absorption chiller. Final report

1984 ◽  
Author(s):  
G. Lof ◽  
M. Westhoff ◽  
S. Karaki
Keyword(s):  
Performance Evaluation ◽  
Cooling System ◽  
Low Cost ◽  
Final Report ◽  
Absorption Chiller ◽  
Solar Cooling ◽  
Solar Cooling System

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.

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.

scholarly journals Thermal Performance Analysis of an Absorption Cooling System Based on Parabolic Trough Solar Collectors

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2679 ◽  
Author(s):  
Jiangjiang Wang ◽  
Rujing Yan ◽  
Zhuang Wang ◽  
Xutao Zhang ◽  
Guohua Shi
Keyword(s):  
Correlation Coefficient ◽  
Cooling System ◽  
Utilization Efficiency ◽  
Design Parameters ◽  
Parabolic Trough ◽  
Absorption Chiller ◽  
Solar Cooling ◽  
Absorption Cooling ◽  
Solar Cooling System ◽  
Absorption Cooling System

Solar radiation intensity significantly influences the cooling loads of building, and the two are correlated and accorded to a certain extent. This study proposes a double effect LiBr–H2O absorption cooling system based on the parabolic trough collector (PTC) of solar heat energy. Thermodynamic models including PTC and absorption chiller are constructed, and their accuracy is verified by comparing the simulation results and the experimental data. Subsequently, the impact of variable design parameters on the thermodynamic performance is analyzed and discussed. The analysis of a solar cooling system in a hotel case study is related to its operation in a typical day, the average coefficient of performance of the absorption chiller is approximately 1.195, and the whole solar cooling system achieves 61.98% solar energy utilization efficiency. Furthermore, the performance comparison of a solar cooling system in different types of building indicates that higher matching and a higher correlation coefficient between the transient solar direct normal irradiance and cooling load is helpful in decreasing the heat loss and improving systemic performance. The solar cooling system in the office building exhibits a correlation coefficient of approximately 0.81 and achieves 69.47% systemic thermal efficiency.

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