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"Cooling systems in tropical countries consume a large part of energy usage in a building, especially in a tropical climate, which places a high demand on cooling systems throughout the year. This paper presents a simulation of a two-bed silica gel-water adsorption chiller, utilizing solar energy based in the tropical climate of Indonesia. The adsorption chiller is being mathematically modelled and calculated numerically using MATLAB®. The simulation is used to show the performance of the chiller during the working hours, based on maximum and minimum inputs of solar irradiation in Indonesia Furthermore, mass recovery and heat recovery is also applied in the adsorption cycle in order to increase the cooling capacity. The adsorption chiller is based on the most recent chiller developed by Shanghai Jiao Tong University (SJTU). The simulation results generally demonstrated the running characteristics of the chiller under a range of different values of solar radiation. Furthermore, the simulation results in detail showed that during the maximum value of irradiation, the average value of COP can reach 0.26, while during the minimum value of irradiation the COP is 0.15. At the same time, the cooling capacity is also varied which can reach up to the maximum value of 37.8 kW, whereas in the minimum range of irradiation values, the cooling capacity dropped to 5.3 kW."

"Cooling systems in tropical countries consume a large portion of the overall energy usage in a building, especially in tropical climates, where there is an especially high demand on cooling systems throughout the year. This paper presents a simulation of the effect of zeolite adsorbent granular size on a zeolite-water solar adsorption chiller for Universitas Indonesia. The adsorption chiller is being mathematically modeled and calculated numerically, using MATLAB®. The mathematical modeling is based on heat transfer principles inside the system for the water inlet and outlet of the system. The adsorption chiller is based on the most recent chiller developed by Shanghai Jiao Tong University (SJTU). The simulation results generally demonstrated the running characteristics of the chiller under a range of different values of granular size. The average granular sizes used in the simulation ranged from 0.5 mm to 1.5 mm. Furthermore, the simulation results showed in detail that the smaller the average granular size of zeolites, the faster the time needed to reach the maximum hot water temperature and the balance state of chilled water outlet temperature."

"ABSTRAKTeknik refrijerasi dengan penyerapan, yang menggunakan energi kalor yang rendah dan mampu menghasilkan pengkondisian udara serta efek refrijerasi, mendapatkan perhatian besar sebagai bagian dari teknologi konversi energi. Teknologi refrijerasi dengan penyerapan mencakup teknologi absorpsi dan teknologi adsorpsi. Naskah ini mempresentasikan desain terbaru chiller adsorpsi silica gel/air yang dikembangkan di Departemen Teknik Mesin, Universitas Indonesia. Konfigurasi chiller terdiri dari dua ruang penyerapan, dengan menggunakan rectangular finned-tube heat exchanger sebagai adsorber, kondenser and evaporator. Chiller diuji pada kondisi temperatur hot water inlet/cooling water inlet sebesar 65/30 C. Heat dan mass recovery diadopsi dalam eksperimen untuk meningkatkan kapasitas pendinginan masing-masing dengan waktu 40 dan 20 detik. Waktu siklus pendinginan pada 800,700,600 dan 500 detik untuk menghasilkan waktu optimal yang berkaitan dengan performa. Nilai rata-rata COP, SCP dan kapasitas pendinginan dihitung untuk mendapatkan performa chiller secara keseluruhan masing-masing 0,6 kW; 0,7 kW/kg dan 3 kW.Kata kunci: chiller adsorpsi; heat recovery; mass recovery; performa; penyerapan; silica gel/air

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ABSTRACTSorption refrigeration, which is driven by the lowgrade heat and provides the air conditioning and refrigeration effect, is paid more and more attention as one of the energy conversion technologies. Sorption technology includes absorption and adsorption technology. This paper presented a new design of silica gel water adsorption chiller which is developed in Mechanical Engineering Department, University of Indonesia. The chiller design configuration is composed of two sorption chamber, with compact rectangular finned tube heat exchanger as adsorber, condenser and evaporator. The chiller is tested under typical condition for hot water inlet cooling water inlet 65 30 C, respectively. Heat and mass recovery were adopted in experiment to increase the cooling capacity time are 40 and 20 s, respectively. The cooling time were 800,700,600 and 500 s to obtain the optimum cooling time related to the performance. Average value of COP, SCP and cooling power were calculated to obtain overall performance of the chiller are 0.6 kW 0.7 kW kg and 3 kW, respectively.Keywords adsorption chiller heat recovery mass recovery performance silica gel water sorption"

"ABSTRAKSistem pendingin adsorpsi merupakan salah satu solusi terkait permasalahan lingkungan yang ditimbulkan oleh pendingin konvensional. Walaupun pendingin adsorpsi menghasilkan COP yang rendah dibandingkan dengan pendingin konvensional, berbagai usaha telah dilakukan untuk meningkatkan performa dari sistem pendingin adsorpsi. Penelitian ini bertujuan untuk mengetahui pengaruh dari waktu siklus adsorpsi/desorpsi dan temperatur inlet chilled water pada performa dari chiller adsorpsi dengan dua bed modular adsorber dan menggunakan dua jenis silica gel sebagai adsorben dan air sebagai adsorbate. Chiller diuji pada setting kondisi temperatur hot water inlet dan cooling water inlet sebesar 75-80oC dan 30oC. Waktu siklus adsorpsi/desorpsi dan temperatur inlet chilled water divariasikan untuk mengetahui pengaruhnya terhadap performa chiller adsorpsi dan untuk memperoleh kondisi optimal berkaitan dengan performa. Hasil eksperimen menunjukkan bahwa setting temperatur inlet chilled water yang lebih rendah menghasilkan performa yang lebih baik pada chiller adsorpsi. Nilai Coefficient of Performance COP dan kapasitas pendinginan maksimum diperoleh sebesar 0.59 dan 3.9 pada saat waktu adsorpsi/desorpsi selama 600s dan setting temperatur inlet chilled water 11 oC.

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ABSTRACTcooling system is one solution related to environmental problems caused by conventional cooling system. Although the adsorption cooling produces a low COP compared to conventional cooling, various efforts have been made to improve the performance of the adsorption cooling system. This study aims to determine the effect of adsorption desorption time and chilled water inlet temperature on the performance of the adsorption chiller with two bed modular adsorber and using two types of silica gel as adsorbent and water as adsorbate. Chiller tested on the setting of hot water inlet temperature conditions and cooling water inlet of 75 80oC and 30oC. The adsorption desorption time and chilled water inlet temperature varied to determine the effect on the performance of the adsorption chiller and to obtain optimal conditions with respect to performance. Experimental results show that the lower temperature inlet setting of chilled water resulted better performance of the adsorption chiller. Coefficient of Performance COP value and maximum cooling capacity were obtained at 0.59 and 3.9 at the time of adsorption desorptiom during 600s and chilled water inlet temperature 11 oC. "