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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."

"ABSTRAKSistem pendingin mengkonsumsi bagian yang besar dari keseluruhan konsumsi energi pada sebuah gedung, terutama di daerah tropis seperti di Indonesia yang mempunyai permintaan sistem pendingin yang besar sepanjang tahun. Naskah ini mempresentasikan simulasi chiller sistem adsorpsi dengan 2 buah adsorber yang memanfaatkan tenaga matahari sesuai iklim di Indonesia. Chiller adsorpsi dimodelkan dan dikalkulasi secara matematika menggunakan perangkat lunak MATLAB®. Simulasi dilakukan secara transien selama jam kerja sehingga mendapatkan nilai temperatur pada titik-titik tertentu pada chiller. Selain itu, sistem mass recovery dan heat recovery juga diaplikasikan dalam sistem untuk memaksimalkan efisiensi. Chiller yang dimanfaatkan berdasarkan pada chiller terbaru yang dikembangkan oleh SJTU. Simulasi dijalankan pada beberapa variasi, yaitu pada input air panas temperatur 60oC dan 90oC untuk mendapatkan range performa chiller, kemudian dilakukan simulasi pada input sesuai radiasi. Selain itu, variasi juga dilakukan dengan penambahan PCM pada tangki air panas untuk meningkatkan efisiensi. Hasil simulasi menunjukkan range performa chiller berada pada COP 0,043-0,342. Secara umum, performa chiller apabila memanfaatkan energi matahari mencapai COP 0,282 dengan kapasitas pendinginan 17 kW, serta dengan adanya PCM mampu meningkatkan performa chiller.

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ABSTRACTCooling system consumes a large part of energy consumption in a building, especially tropical area like Indonesia which has a high demand of cooling system along the year. This paper presented a simulation of two bed silica gel-water adsorption chiller utilizing solar energy based on Indonesia climate. The adsorption chiller is being mathematically modelled and calculated numerically using MATLAB®. The simulation is run transiently at working hours to achieve temperature in some points in the system. Furthermore, mass recovery and heat recovery is also applied in the adsorption cycle in order to increase the efficiency. The adsorption chiller is based on the most recent development by SJTU. Simulation is being run in some variations, for the stable hot water temperature in 60oC and 90oC in order to get the range of chiller performance. Then simulation is run using the radiation data as input energy. Another variation using PCM is also added to the hot water tank in order to increase the efficiency. The simulation results demonstrated the running characteristic of the chiller with the range of COP 0.043-0.342. In general, the chiller performance can reach COP 0.282 with 19 kW cooling capacity when utilize the solar radiation as input energy. Moreover, Adding PCM in hot water tank also can improve the chiller’s performance."

"ABSTRAKSolar Thermal Cooling System with its absorption cycle is expected toreplace the conventional air conditioning system with vapor compression cyclebecause it is more efficient in terms of cost and energy. However, due to the heatof the sun is not always stable, the system needs to be equipped with a backupenergy source, one of which is CNG. In the Manufacturing Research Centerbuilding, the lack of facilities that support availability of CNG causes largeoperating costs. Therefore, Optimization efforts with the aim to reduce operatingcosts are needed. Simulation and optimization performed with EnergyPlus andGenOpt. The conclusion is that the installation of 100 kW electric heater tanklesshot water storage tank is able to reduce total operating costs by 34.95% comparedto the use of a combination of solar thermal and CNG and 49.92% compared withthe full use of CNG.

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ABSTRACTSolar Thermal Cooling System with its absorption cycle is expected toreplace the conventional air conditioning system with vapor compression cyclebecause it is more efficient in terms of cost and energy. However, due to the heatof the sun is not always stable, the system needs to be equipped with a backupenergy source, one of which is CNG. In the Manufacturing Research Centerbuilding, the lack of facilities that support availability of CNG causes largeoperating costs. Therefore, Optimization efforts with the aim to reduce operatingcosts are needed. Simulation and optimization performed with EnergyPlus andGenOpt. The conclusion is that the installation of 100 kW electric heater tanklesshot water storage tank is able to reduce total operating costs by 34.95% comparedto the use of a combination of solar thermal and CNG and 49.92% compared withthe full use of CNG."

"Seperti kita ketahui, Indonesia memiliki banyak sumber energi yang dapat dimanfaatkan sebagai bahan bakar pembangkit listrik, antara lain Energi Air, Energi Surya, Energi Angin, Energi Panas Bumi dan Energi Gas. Pembangkit listrik tenaga gas memiliki banyak keunggulan dari energi yang laiinnya karena tidak bergntung pada kondisi cuaca seperti angin, intensitas cahaya atau laju aliran air. Potensi gas alam indonesia sebagai sumber bahan bakar Pembangkit Listrik Tenaga Gas (PLTG) sangat melimpah. Menurut studi badan geologi kementerian Energi dan Sumber Daya Alam (ESDM), potensi gas alam yang ada di Indonesia pada tahun 2008 saja mencapai 170 TSCF, dengan komposisi tersebut Indonesia memiliki reserve to production (R/P) mencapai 59 tahun ke depan. Pembangkit listrik tenaga gas memiliki efisiensi yang cukup rendah akibat temperatur gas buang yang masih tinggi. Efisiensi dapat ditingkatkan dengan memanfaatkan sistem pendingin untuk menaikkan efisiensi kerjanya. Namun apabila pembangkit tersebut telah dibuat dengan siklus kombinasi menjadi gas dan uap maka ada sistem pendingin menjadi kurang optimum karena gas buangnya sudah terpakai sebagai sumber panas HRSG. Dalam penelitian ini temperatur udara masuk gas diturunkan hingga temperatur 15o C. Untuk penurunan temperatur ambient hingga 150C terjadi kenaikan daya output turbin gas sebesar 15,14 MW dan kenaikan efisiensi themal siklus sebesar 3,9 %. Sumber panas yang didapatkan generator chiller berasal dari HRSG dengan laju aliran massa steam sebesar 6,37 kg/s. Hal ini mengakibatkan penurunan daya output turbin uap berkurang sebesar 3,27 MW. Akan tetapi, dengan adanya sistem pendingin pada absorption chiller ini daya output yang dihasilkan oleh turbin gas meningkat sebesar 11,87 MW.

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As we know, Indonesia has many sources of energy that can be used as fuel for power generation, among others, Air Energy, Solar Energy, Wind Energy, Geothermal Energy and Energy Gas. Gas power plants have many advantages of energy because it does not bergntung laiinnya on weather conditions such as wind, light intensity or rate of water flow. The potential of Indonesian natural gas as a fuel source Gas Power Plant (power plant) is very abundant.

According to the study of geological bodies Ministry of Energy and Natural Resources (EMR), the potential of natural gas in Indonesia in 2008 alone reached 170 TSCF, with the composition of Indonesia has a reserve to production (R / P) reached 59 years into the future. Gas power plants have a fairly low efficiency due to the exhaust gas temperature is still high. Efficiency can be improved by utilizing the cooling system to increase its efficiency. However, if the plant has been made with a combined cycle gas and steam into the existing cooling system becomes less optimal because the exhaust gas has been used as a heat source HRSG.

In this study the gas intake air temperature is reduced to a temperature of 15°C. To decrease ambient temperatures of up to 150C an increase in power output of 15.14 MW gas turbine and an increase in efficiency of 3.9% themal cycles. The heat source is obtained chiller generator comes from HRSG with steam mass flow rate of 6.37 kg / s. This resulted in a decrease in the steam turbine output power is reduced by 3.27 MW. However, the presence of the absorption chiller cooling system's power output generated by gas turbines increased by 11.87 MW."

"Kelembaban merupakan parameter yang menunjukan kandungan air dalam udara. Untuk menurunkan kelembaban, dapat dilakukan dehumidifikasi dengan proses overcooling dan reheating menggunakan cooling coil dan heater. Dengan menggunakan U-bend heat pipe, proses dehumidifikasi dapat dilakukan tanpa menggunakan alat pemanas tambahan. Dengan begitu kita dapat menghemat energi yang dipakai daripada sistem sebelumnya. Salah satu kebutuhan dehumidifikasi adalah untuk memenuhi kebutuhan termal dari ruang bersih. Pada Skripsi ini dilakukan permodelan dan simulasi sistem U-bend Heat Pipe sebagai dehumidifier. Simulasi dilakukan dengan menggunakan software ANSYS FLUENT 2020 R1 Student Version. Kemudian dari hasil simulasi dilakukan analisa apakah dengan model konfigurasi heat pipe yang dibuat apakah memenuhi kebutuhan termal ruang bersih sesuai dengan ASHRAE Standard 22 - 24 °C dan 40 - 60 % RH serta karakteristik efektivitas heat pipe terhadap temperatur dan kecepatan inlet. Hasil simulasi menunjukan heat recovery tertinggi didapatkan dari kondisi kecepatan udara 2.0 m/s dan temperatur inlet 45 °C yaitu sebesar 199.30 W. Efektivitas terbaik berada pada kondisi kecepatan udara 0.5 m/s yaitu sebesar 55.4 %. Dari perolehan data, efektivitas berbanding terbalik dengan kecepatan inlet dan sistem heat pipe dapat memenuhi standar keadaan temperatur dan RH dari ruang bersih. U-Bend Heat Pipe baik diterapkan untuk dehumidifikasi karena dapat menggantikan fungsi heater dan mengurangi beban pendinginan sebesar 55.4 % pada kecepatan inlet 0.5 m/s untuk menurunkan relative humidity sampai dengan 57% RH.

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Humidity is an important parameter to show water vapour contained in air. Overcooling and reheating using cooling coil and heater can be used to lower the humidity. With Ubend heat pipe, dehumidification can be done without additional heater. So the energy used will be lower than previous system. One of the needs of dehumidification is to satisfy thermal needs of a cleanroom. In this final project, U-bend Heat Pipe system is being modelled and simulated for dehumidification. System is simulated with ANSYS FLUENT 2020 R1 Student Version software. The simulation result then be analyzed to see if the said heat pipe system is fulfilling thermal needs of the cleanroom corresponding to ASHRAE Standard 22 - 24 °C and 40 - 60% RH. Also to observe the characteristic of heat pipe effectivity to inlet velocity and inlet temperature. The simulation result shows highest heat recovery 199.30 W is obtained on 2.0 m/s inlet velocity and 45 °C inlet temperature. The best effectivity 55.4 % is obtained on 0.5 m/s. The simulation shows that effectivity is directly proportional to inlet velocity and heat pipe system can fulfill the standard thermal needs of a cleanroom. U-Bend Heat Pipe is recommended to be applied for dehumidification because it can replace heater’s function and lighten the cooling load by 55.4 % at 0.5 m/s inlet velocity to lower the relative humidity up to 57% RH.

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