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R. Z. Wang – 1st expert on this subject based on the ideXlab platform
experimental study of an Adsorption Chiller for extra low temperature waste heat utilizationApplied Thermal Engineering, 2019Co-Authors: Jiajie Peng, R. Z. WangAbstract:
Abstract Lots of low temperature waste heat exists in industrial fields which also requires cooling processes, i.e.: data center and glass and liquid crystal display panel manufacturing. Silica gel-water Adsorption refrigeration can well match the operation temperature in waste heat utilization for these applications but its technical feasibility and experimental performance is not studied. In this paper, a silica gel-water Adsorption Chiller using mass recovery process is built and experimentally studied under the condition of lower than 80 °C driving hot water temperature. For the case of data center waste heat utilization, the Adsorption Chiller can be well operated under the condition of driving temperatures of 51.4–61.3 °C, with the COPs (coefficient of performance) of 0.285–0.477 and SCPs (specific cooling power) of 71.2–108.4 W∙kg−1 while producing 18.8–22.4 °C chilled water. For the cases of glass and liquid crystal display panel manufacturing waste heat utilization, COPs of 0.317–0.483 and SCPs of 95.2–146.7 W∙kg−1 are obtained under the conditions of driving temperatures of 56.2–74.9 °C and chilled water outlet temperatures of 14.2–16.8 °C. These experimental results indicate that feasibility in operation and good performance of silica gel-water Adsorption Chiller for extra low temperature waste heat utilization is confirmed.
study on operation strategy of a silica gel water Adsorption Chiller in solar cooling applicationSolar Energy, 2018Co-Authors: R. Z. WangAbstract:
Abstract Conventional operation strategy of silica gel-water Adsorption Chiller in solar cooling application uses fixed cycle time, but it deviates from real optimal cycle time because of varied solar hot water temperature. Mathematical model and simulation of a solar silica gel-water Adsorption Chiller was done and performance comparison in two operating strategies (fixed and varied cycle time) was made according to experiment data of a real solar system. An estimating equation for the optimal cycle time was developed by the simulation results, considering both COP and SCP by a weighting factor. Correlation of optimal cycle time and hot water temperature was fitted in a linear equation. Optimal half cycle time decreased with increasing hot water temperature and weighting factor. COPs of varied cycle time were much larger than those of fixed cycle time whereas SCPs of varied cycle time and fixed cycle time were nearly the same. So operation strategy of silica gel-water Adsorption Chiller with varied cycle time can significantly improve the whole utilization efficiency of solar cooling system without any decrease in cooling capacity.
low temperature grain storage with a solar powered Adsorption Chiller a case studyInternational Journal of Green Energy, 2014Co-Authors: R. Z. Wang, Jiamin ShenAbstract:
Solar energy refrigeration is very attractive for low-temperature grain storage because the cooling load of low-temperature grain storage is roughly in phase with solar energy availability. In this study, a solar-powered Adsorption Chiller was developed with aim of developing an alternative refrigeration device for low-temperature grain storage. The solar-powered Adsorption Chiller was put into experimental operation during summer and autumn. Test results show that the solar-powered Adsorption Chiller can produce a cooling capacity about 66–90 W per m2 collector area. Its daily solar-cooling COP (coefficient of performance) is about 0.1–0.13 under the climatic conditions of daily solar radiation being about 16–21 MJ/m2·day. With appropriate ventilation appliance, this kind of solar-powered Adsorption Chiller could be considered as an alternative for low-temperature grain storage in most areas of China.
Bidyut Baran Saha – 2nd expert on this subject based on the ideXlab platform
solar thermal powered Adsorption Chiller, 2020Co-Authors: Mahbubul Muttakin, Bidyut Baran SahaAbstract:
Adsorption based cooling systems are gaining considerable attention since it can utilize low grade thermal energy, which otherwise could go as a waste. Heat sources possessing a temperature of as low as 60 °C can drive an Adsorption Chiller and that temperature requirement is even lower in the case of multi-stage Adsorption cooling systems. A typical flat plate solar collector can provide hot water having a temperature of 65 °C in most of the countries in the Asian region. The temperature of evacuated tube collectors’ water outlet can reach above 95 °C. In order to make use of such collectors, in conjunction with other auxiliary heat sources, for providing heat to power an Adsorption Chiller, it is imperative to have a proper mathematical model. This can aid in designing the network and predicting the performance of the whole system, prior to installation. This chapter focuses on the modelling of a system that incorporates flat plate collectors, evacuated tube collectors and a thermally powered Adsorption Chiller. Here, mathematical equations to calculate the efficiency of flat plate and evacuated tube collectors are presented; processes that are involved in a typical two bed Adsorption cooling system are explained in brief, and a mathematical model of an Adsorption Chiller, that employs mass and heat recovery schemes is developed. Finally, the simulation results of the model are presented, and the performance of the Chiller is investigated to demonstrate a clear understanding of its operation.
Dynamic behaviors of Adsorption Chiller: Effects of the silica gel grain size and layersEnergy, 2014Co-Authors: Anutosh Chakraborty, Bidyut Baran Saha, Yu I AristovAbstract:
This article presents the dynamic behaviour of a single effect two bed Adsorption Chiller employing adsorbent beds with various layers of loose grain configurations and silica gel particle sizes, 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 silica gel configuration in terms of layers and sizes provides an interesting result, that is, the “grain size sensitive” regime is realized for large adsorbent grains with more layers. From numerical simulation, it is found that the specific cooling power and the coefficient of performance are reduced and the peak chilled water temperatures are increased with increasing the grain size and grain layers. We also demonstrate here that the sizes and layers of adsorbents should be considered for the design of Adsorption heat exchanger for Adsorption cooling applications.
study on a solar heat driven dual mode Adsorption ChillerEnergy, 2013Co-Authors: Khairul Habib, Bidyut Baran Saha, Biplab Choudhury, Pradip Kumar ChatterjeeAbstract:
Environmental concerns and the rising energy cost necessitate looking for renewable energy driven environmentally benign Adsorption cooling systems. Solar powered Adsorption Chillers with non-concentrating flat plate or evacuated tube collectors face the problem of not getting adequate driving source temperature during some months of the year. Multi-staging of the Adsorption cycle is then needed to exploit the low driving source temperature. A simulation study of a solar thermal driven dual-mode, four-bed silica gel–water Adsorption Chiller is undertaken in this work. The solar thermal collector data of Durgapur (23.48 °N, 87.32 °E), India has been used as the heat source for the dual-mode Chiller. For a driving source temperature above 60 °C, the Chiller works as a single stage four-bed Adsorption Chiller; while the Chiller functions as a two stage Adsorption Chiller when the driving source temperature falls below 60 °C. With a cooling water temperature of 30 °C, this two stage Chiller has been found to produce cooling effect with a driving source temperature as low as 40 °C. Results indicate that the dual-mode Chiller is capable of providing cooling throughout the year under the climatic condition of Durgapur, India.
Atsushi Akisawa – 3rd expert on this subject based on the ideXlab platform
experimental study on a three bed Adsorption ChillerInternational Journal of Air-conditioning and Refrigeration, 2011Co-Authors: M Z I Khan, Bidyut Baran Saha, Shahnaz Sultana, Atsushi AkisawaAbstract:
This article presents the experimental results of a three-bed advanced Adsorption Chiller using silica gel–water as the adsorbent–refrigerant pair. The three-bed Adsorption Chiller comprises three sorption elements (Hexs), one evaporator and one condenser. In the present study, the heat source temperature varies from 55°C to 80°C along with coolant inlet temperature at 30°C and the chilled water inlet temperature at 14°C. Mass recovery process occurs between Hex1 and Hex2 and no mass recovery with Hex3. The performances in terms of cooling capacity (CC) and coefficient of performance (COP) are compared with those of conventional three-bed without mass recovery scheme. Results show that three-bed with mass recovery scheme provides more CC values than those provided by the three-bed system without mass recovery scheme while it provides better COP values for 65–75°C heat source temperature.
the performance analysis of a novel dual evaporator type three bed Adsorption ChillerInternational Journal of Refrigeration-revue Internationale Du Froid, 2010Co-Authors: Takahiko Miyazaki, Atsushi Akisawa, Bidyut Baran SahaAbstract:
Abstract This paper deals with the performance evaluation of an innovative, waste heat driven dual evaporator type three-bed Adsorption cycle for cooling application. The innovative Adsorption Chiller has two evaporators, three adsorbent beds, and a condenser, and the evaporators work at different pressure levels. The effects of hot water inlet temperature, chilled water inlet and outlet temperatures, and cycle time on the specific cooling capacity (SCC) and coefficient of performance (COP) were predicted by simulation. For the same operating condition, the SCC and COP of the dual evaporator type three-bed Adsorption Chiller were found to be 1.5 and 1.7 times higher than those of the two-bed single-stage Adsorption Chiller, respectively.
The performance analysis of a novel dual evaporator type three-bed Adsorption ChillerInternational Journal of Refrigeration, 2010Co-Authors: Takahiko Miyazaki, Atsushi Akisawa, Bidyut Baran SahaAbstract:
This paper deals with the performance evaluation of an innovative, waste heat driven dual evaporator type three-bed Adsorption cycle for cooling application. The innovative Adsorption Chiller has two evaporators, three adsorbent beds, and a condenser, and the evaporators work at different pressure levels. The effects of hot water inlet temperature, chilled water inlet and outlet temperatures, and cycle time on the specific cooling capacity (SCC) and coefficient of performance (COP) were predicted by simulation. For the same operating condition, the SCC and COP of the dual evaporator type three-bed Adsorption Chiller were found to be 1.5 and 1.7 times higher than those of the two-bed single-stage Adsorption Chiller, respectively. © 2009 Elsevier Ltd and IIR.