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Bidyut Baran Saha - One of the best experts on this subject based on the ideXlab platform.

  • improved Cooling Capacity of a solar heat driven adsorption chiller
    Case Studies in Thermal Engineering, 2020
    Co-Authors: Rifat Ara Rouf, Bidyut Baran Saha, K C A Alam, N Jahan, A A Sultan, Suvash C Saha
    Abstract:

    Abstract This paper discusses two investigations which indicate the benefit of exploiting multiple adsorption containers to increase the Cooling energy output of a limited supply of solar heat. First, the optimum working conditions on the output of a solar-powered 3-bed adsorption Cooling scheme working in a series and secondly, the performance of a new parallel system of 4-beds has been investigated. It is seen that especially when the source of heat is limited, the output of solar assisted adsorption cooler can be enhanced if the total amount of adsorbent can be distributed in three identical small adsorption beds. As a continuation of the study with multiple beds, the performance of a newly proposed Cooling unit with 4-beds has also been studied. This parallel system of 4-beds is considered in such a way that, when one conventional 2-bed chiller is in adsorption/desorption mode then the other chiller is in the preheat/pre-cool mode and the system goes on alternately. Both of these chillers are linked with a single evaporator and condenser, resulting in a continuous evaporation and condensation process. Both of these new systems with multiple beds can utilize maximum entropy as exploits a longer precool time and improves specific Cooling Capacity (SCC).

  • potential application of solar powered adsorption Cooling systems in the middle east
    Applied Energy, 2014
    Co-Authors: Bidyut Baran Saha, Ibrahim I Elsharkawy, Hossam Abdelmeguid
    Abstract:

    This paper presents a theoretical investigation on the performance of solar powered silica gel/water based adsorption Cooling system working under climate conditions of the Middle East region. Actual solar data of Cairo and Aswan located, respectively, in the north and south of Egypt and the coastal city Jeddah on the Red Sea in Saudi Arabia are used in this study. Dynamic behavior of adsorption chillers driven by compound parabolic solar collector is presented. Two system configurations have been considered herein; (i) adsorption chiller is directly connected to the solar collectors, (ii) hot water buffer storage is installed between adsorption chiller and solar collectors. Temporal history of solar collector, sorption reactors, evaporator and condenser has been predicted. System performance in terms of Cooling Capacity, daily average Cooling Capacity, cycle COP and solar COP has been estimated. Results show that the maximum cyclic Cooling Capacity of the system working under Cairo and Jeddah climate conditions reaches about 14.8kW and about 15.8kW for Aswan climate conditions.

  • a new generation Cooling device employing cacl2 in silica gel water system
    International Journal of Heat and Mass Transfer, 2009
    Co-Authors: Bidyut Baran Saha, Shigeru Koyama, Anutosh Chakraborty, Yu I Aristov
    Abstract:

    Abstract This article presents the dynamic modelling of a single effect two-bed adsorption chiller utilizing the composite adsorbent “CaCl 2 confined to KSK silica gel” as adsorbent and water as adsorbate, which is based on the experimentally confirmed adsorption isotherms and kinetics data. Compared with the experimental data of conventional adsorption chiller based on RD silica gel + water pair, we found that the new working pair provides better Cooling Capacity and performances. From numerical simulation, it is also found that the Cooling Capacity can be increased up to 20% of the parent silica gel + water adsorption chiller and the coefficient of performance (COP) can be improved up to 25% at optimum conditions. We also demonstrate here that the best peak chilled water temperature suppression, and the maximum Cooling Capacity can be achieved by the optimum analysis for both cycles.

R Z Wang - One of the best experts on this subject based on the ideXlab platform.

  • case study and theoretical analysis of a solar driven two stage rotary desiccant Cooling system assisted by vapor compression air conditioning
    Solar Energy, 2011
    Co-Authors: Dong La, T.s. Ge, Yong Li, R Z Wang
    Abstract:

    Abstract In this paper, a solar hybrid desiccant air conditioning system, which combines the technologies of two-stage desiccant Cooling (TSDC) and air-source vapor compression air-conditioning (VAC) together, has been configured, experimentally investigated and theoretically analyzed. The system mainly includes a TSDC unit with design Cooling Capacity for 10 kW, an air-source VAC unit with 20 kW in nominal Cooling Capacity, a flat plate solar collector array for 90 m2, a hot water storage tank and a Cooling tower. Performance model of the system has been created in TRNSYS simulation studio. The objective of this paper is to report the test result of the solar hybrid air conditioning system and evaluate the energy saving potential, thereby providing useful data for practical application. Experimental results show that, under typical weather condition, the solar driven desiccant Cooling unit can achieve an average Cooling Capacity of 10.9 kW, which contributes 35.7% of the Cooling Capacity provided by the hybrid system. Corresponding average thermal COP is over 1.0, electric COP is up to 11.48. Under Beijing (temperate), Shanghai (humid) and Hong Kong (extreme humid) weather conditions, the solar TSDC unit can remove about 57%, 69% and 55% of the seasonal moisture load, thereby reducing electric power consumption by about 31%, 34% and 22%, respectively. These suggest that the solar hybrid system is feasible for a wide range of operating conditions.

  • design and performance prediction of a new generation adsorption chiller using composite adsorbent
    Energy Conversion and Management, 2011
    Co-Authors: L.x. Gong, R Z Wang, Congying Chen
    Abstract:

    Abstract This paper presents a novel adsorption chiller using composite adsorbent “employing lithium chloride in silica gel” as adsorbent and water as adsorbate. A new type adsorbent bed is used to accommodate the composite adsorbent. The mass recovery between two adsorbent beds usually results in the adsorbate unbalance. So a novel auto water makeup unite is used to solve the problem. A dynamic model of the adsorption chiller is built based on the adsorption isotherms to predict the performance. The simulation result shows that the coefficient of performance (COP) and the Cooling Capacity will increase by using this new composite adsorbent. When the temperatures of hot water inlet, Cooling water inlet, and chilled water inlet are 363, 303 and 293 K, COP will be 0.43, and the Cooling Capacity will be 5.295 kW. Also operation strategy is optimized. Different temperatures of hot water inlet, Cooling water inlet and chilling water inlet will result in different COP and Cooling Capacity.

Amgad R. Rezk - One of the best experts on this subject based on the ideXlab platform.

  • physical and operating conditions effects on silica gel water adsorption chiller performance
    Applied Energy, 2012
    Co-Authors: Amgad R. Rezk, Raya Aldadah
    Abstract:

    Abstract Adsorption refrigeration systems are commercially developed due to the need of replacing the conventional systems which utilise environmentally harmful refrigerants and consume high grade electrical power. This paper presents the key equations necessary for developing a novel empirical lumped analytical simulation model for commercial 450 kW two-bed silica gel/water adsorption chiller incorporating mass and heat recovery schemes. The adsorption chiller governing equations were solved using MATLAB® platform integrated with REFPROP® to determine the working fluids thermo-physical properties. The simulation model predicted the chiller performance within acceptable tolerance and hence it was used as an evaluation and optimisation tool. The simulation model was used for investigating the effect of changing fin spacing on chiller performance where changing fin spacing from its design value to minimum permissible value increased chiller Cooling Capacity by 3.0% but decreased the COP by 2.3%. Furthermore, the effect of generation temperature lift on chiller performance and the feasibility of using it as a load control tool will be discussed. Genetic Algorithm optimisation tool was used to determine the optimum cycle time corresponding to maximum Cooling Capacity, where using the new cycle time increased the chiller Cooling Capacity by 8.3%.

  • Physical and operating conditions effects on silica gel/water adsorption chiller performance
    Applied Energy, 2011
    Co-Authors: Amgad R. Rezk, Raya K. Al-dadah
    Abstract:

    Abstract Adsorption refrigeration systems are commercially developed due to the need of replacing the conventional systems which utilise environmentally harmful refrigerants and consume high grade electrical power. This paper presents the key equations necessary for developing a novel empirical lumped analytical simulation model for commercial 450 kW two-bed silica gel/water adsorption chiller incorporating mass and heat recovery schemes. The adsorption chiller governing equations were solved using MATLAB® platform integrated with REFPROP® to determine the working fluids thermo-physical properties. The simulation model predicted the chiller performance within acceptable tolerance and hence it was used as an evaluation and optimisation tool. The simulation model was used for investigating the effect of changing fin spacing on chiller performance where changing fin spacing from its design value to minimum permissible value increased chiller Cooling Capacity by 3.0% but decreased the COP by 2.3%. Furthermore, the effect of generation temperature lift on chiller performance and the feasibility of using it as a load control tool will be discussed. Genetic Algorithm optimisation tool was used to determine the optimum cycle time corresponding to maximum Cooling Capacity, where using the new cycle time increased the chiller Cooling Capacity by 8.3%.

Raya Aldadah - One of the best experts on this subject based on the ideXlab platform.

  • physical and operating conditions effects on silica gel water adsorption chiller performance
    Applied Energy, 2012
    Co-Authors: Amgad R. Rezk, Raya Aldadah
    Abstract:

    Abstract Adsorption refrigeration systems are commercially developed due to the need of replacing the conventional systems which utilise environmentally harmful refrigerants and consume high grade electrical power. This paper presents the key equations necessary for developing a novel empirical lumped analytical simulation model for commercial 450 kW two-bed silica gel/water adsorption chiller incorporating mass and heat recovery schemes. The adsorption chiller governing equations were solved using MATLAB® platform integrated with REFPROP® to determine the working fluids thermo-physical properties. The simulation model predicted the chiller performance within acceptable tolerance and hence it was used as an evaluation and optimisation tool. The simulation model was used for investigating the effect of changing fin spacing on chiller performance where changing fin spacing from its design value to minimum permissible value increased chiller Cooling Capacity by 3.0% but decreased the COP by 2.3%. Furthermore, the effect of generation temperature lift on chiller performance and the feasibility of using it as a load control tool will be discussed. Genetic Algorithm optimisation tool was used to determine the optimum cycle time corresponding to maximum Cooling Capacity, where using the new cycle time increased the chiller Cooling Capacity by 8.3%.

Raya K. Al-dadah - One of the best experts on this subject based on the ideXlab platform.

  • Physical and operating conditions effects on silica gel/water adsorption chiller performance
    Applied Energy, 2011
    Co-Authors: Amgad R. Rezk, Raya K. Al-dadah
    Abstract:

    Abstract Adsorption refrigeration systems are commercially developed due to the need of replacing the conventional systems which utilise environmentally harmful refrigerants and consume high grade electrical power. This paper presents the key equations necessary for developing a novel empirical lumped analytical simulation model for commercial 450 kW two-bed silica gel/water adsorption chiller incorporating mass and heat recovery schemes. The adsorption chiller governing equations were solved using MATLAB® platform integrated with REFPROP® to determine the working fluids thermo-physical properties. The simulation model predicted the chiller performance within acceptable tolerance and hence it was used as an evaluation and optimisation tool. The simulation model was used for investigating the effect of changing fin spacing on chiller performance where changing fin spacing from its design value to minimum permissible value increased chiller Cooling Capacity by 3.0% but decreased the COP by 2.3%. Furthermore, the effect of generation temperature lift on chiller performance and the feasibility of using it as a load control tool will be discussed. Genetic Algorithm optimisation tool was used to determine the optimum cycle time corresponding to maximum Cooling Capacity, where using the new cycle time increased the chiller Cooling Capacity by 8.3%.