scholarly journals PEMANFAATAN KOLEKTOR SURYA SEBAGAI ENERGI ALTERNATIF DESALINASI AIR LAUT UNTUK MENGATASI KRISIS AIR BERSIH

2017 ◽  
Vol 7 (2) ◽  
pp. 59
Author(s):  
Dedet Hermawan Setiabudi ◽  
Muhrom Khudhori

This research examined the effect of air velocity and the efficiency of double-pass flat plate solar air heater with two glass covers on the performance of solar desalination unit based on heat pump with using humidification and dehumidification processes. This unit consists of a heat pump, humidifier, dehumidifier, and double-pass flat plate solar air heater with two glass covers. The research was conducted in an indoor experiment. Solar energy generated from solar simulator using halogen lamps. In this research the air flow rate was varied at 3 metres per second, 4 metres per second, 5 metres per second, and 6 metres per second, while the intensity of solar radiation at 828 Watts per meter squared. At each variation in air velocity, sea water temperature was conditioned at a constant temperature of 45 degrees celcius, the compressor was operated at a constant rotation of 900 rpm, volumetric flow rate of sea water inlet 300 liters per hour into humidifier and sea water in this system was re-circulated. The research result showed that the volume of fresh water production increases with increasing air velocity inlet into humidifier. This solar desalination unit could produce fresh water maximum 2470 milliliters per hour in air velocity 6 metres per second.

2021 ◽  
Vol 1 (01) ◽  
pp. 101-106
Author(s):  
Dedet Hermawan S

Penelitian ini menguji pengaruh kecepatan udara dan efisiensi pemanas udara surya double-pass flat plate dengan dua penutup kaca terhadap kinerja unit desalinasi surya berbasis pompa panas dengan menggunakan proses humidifikasi dan dehumidifikasi. Unit ini terdiri dari heat pump, humidifier, dehumidifier, dan double-pass flat plate solar air heater dengan dua penutup kaca. Penelitian ini dilakukan dalam eksperimen dalam ruangan. Energi surya yang dihasilkan dari simulator surya menggunakan lampu halogen. Pada penelitian ini debit aliran udara divariasikan pada 3 m/s, 4 m/s, 5 m/s, dan 6 m/s, sedangkan intensitas radiasi matahari divariasikan pada 828 W/m², 924 W/m², dan 1014 W/m². Pada setiap variasi kecepatan udara, suhu air laut dikondisikan pada suhu konstan 45oC, kompresor dioperasikan pada putaran konstan 900 rpm, laju aliran volumetrik air laut masuk 300 liter/jam ke humidifier dan air laut dalam sistem ini disirkulasikan kembali. Hasil penelitian menunjukkan bahwa volume produksi air tawar meningkat dengan meningkatnya kecepatan udara masuk ke dalam humidifier. Unit desalinasi surya ini mampu menghasilkan air tawar maksimum 3691 mililiter/jam pada kecepatan udara 6 m/s dan intensitas radiasi matahari 1014 W/m².  


2020 ◽  
Vol 12 (9) ◽  
pp. 3619
Author(s):  
Afaq Jasim Mahmood

In this study, an experimental outdoor investigation of the thermal efficiency and outlet air temperature was conducted on an unglazed, double-pass, solar air heater with a perforated absorber plate and packing wire mesh layers as a supplemental absorbent area. This was done to observe their effects on the thermal performance of the solar air heater. The double-pass collector was constructed with a bed height of 0.05 m, and a collection area of 1.5 m2. The height of the upper channel was fixed at 0.015 m to improve the thermal efficiency, and the outlet temperature at air flow rates between 0.003 and 0.018 kg/s. The collector was mounted with a slope of 42° facing south, to maximize the intensity of solar irradiance during winter. The effects of the air flow rate, ambient temperature, inlet temperature, outlet temperature, and solar intensity were experimentally investigated. The results showed that thermal efficiency could be improved by increasing the air flow rate, where the highest thermal efficiency achieved was 86% at 0.018 kg/s. However, the temperature difference was increased to a maximum value of 38.6 °C, when the air flow rate was decreased to 0.003 kg/s. Furthermore, the results demonstrated a significant improvement in the thermal efficiency and outlet temperature; and when compared with previous research, the experimental results and the predictions for the outlet temperature using the theoretical model agreed.


MECHANICAL ◽  
2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Indri Yaningsih ◽  
Tri Istanto

This research examined the effect of the use of spray humidifier and pad humidifier on the productivity of a desalination unit based heat pump with using humidification and dehumidification process. In spray humidifier there were 5 pieces of sprinklers for spraying sea water. In pad humidifier, sea water was distributed evenly over the top by means of sea water flowing through perforated pipes that have been placed on pad humidifier. Tested the effect of sea water volumetric flow rate, air velocity and sea water temperature which was fed to spray humidifier and pad humidifier on the fresh water production resulted from desalination unit.The research result showed that the production of fresh water increased with the increase in the sea water volumetric flow rate, air velocity, and sea water temperature, this applies to the use of spray humidifier or pad humidifier in the desalination unit.On testing of the effect of the sea water volumetric flow rate, air velocity, and sea water temperature, the performance of spray humidifier and pad humidifier was equal in the production of fresh water, when the ratio of sea water mass flow rate to air mass flow rate of 1.34, 1.3 and 1.3, respectively.Keywords : dehumidification,desalination, humidification, pad humidifier, spray humidifier


2017 ◽  
Vol 139 (3) ◽  
Author(s):  
Afaq Jasim Mahmood

This study presents a new design for improving the convection heat transfer coefficients of double-pass solar air heater. Three cases were described by using a different number of transverse baffles (three, five, and seven) in the lower channel of the collectors; steel mesh sheets were also used to enlarge the heat transfer area. All collectors have a space of 25 mm between its glass covers and a 50 mm depth of air channel. Furthermore, this work examined the effect of air flow rate and baffles number on device's thermal efficiency and outlet temperature. The experimental results indicate raises in the thermal efficiency as the air flow rate goes from 0.011 kg/s to 0.038 kg/s. A maximum efficiency of 68% was obtained from the case of seven baffles at the air flow rate of 0.038 kg/s. Moreover, the difference between collector's inlet and outlet temperatures, ΔT, indicated an inverse relationship with air flow rate. Thus, the results show ΔT increases as the air flow rate reduced. The maximum temperature difference recorded was 54 °C, which achieved using seven baffled solar air heater at 0.011 kg/s air flow rate in the middle of the day. It has also been found that thermal efficiency of double-pass solar air heater is greater than single-pass solar air heater, using same air flow rate and number of baffles. Finally, the pressure drop associated with increasing the number of baffles and air flow rate was deliberated.


2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Satyender Singh ◽  
Prashant Dhiman

The present work intended to investigate thermal and thermohydraulic efficiencies of two different models of recyclic double pass packed bed solar air heaters experimentally. Model-I consists of single air pass through two glass covers as well as double air pass caused due to recycle of the air exiting from the packed bed duct formed between the absorber plate and the glass cover through another duct integrated between the absorber and back plates to inlet of the packed bed duct. On the other hand, model-II consists of only double air pass originated due to recycle operation constituted between the similar solar air heater elements as that of model-I. Twelve numbers of wire mesh screens to form 95% bed porosity were used. Both solar air heater models were tested under the range of packed bed Reynolds number from 300 to 1500 for air mass flow rate and recycle ratio of 0.01 kg/s to 0.025 kg/s and 0.3 to 1.8, respectively. Results revealed that thermal performance of model-I is found to be 15% higher than that of model-II. The optimum value of the recycle ratio for model-I and model-II are obtained as 0.9 and 1.2, respectively, at a mass flow rate of 0.025 kg/s that yields the best thermohydraulic efficiency of 77% and 67%, respectively. Moreover, optimum solution for recycle ratio and air mass flow rate during off sun shine hours are also obtained and presented in the current work.


2016 ◽  
Vol 20 (1) ◽  
pp. 175-183 ◽  
Author(s):  
Gnanadurai Sugantharaj ◽  
Kumar Vijay ◽  
Kalidasa Kulundaivel

Solar air heating is a technology in which the solar energy from the sun is captured by an absorbing medium and used to heat the air flowing through the heater. In this study, thermal performance of a double pass solar air heater has been investigated experimentally at different conditions. The experiments were conducted with different inclinations of the collector, with and without wire mesh vertically fixed at the second pass in transverse direction and with different mass flow rates. The effect of air mass flow rate, wire mesh pitch and collector inclination on temperature rise and thermal efficiency have been studied. Results show that efficiency increases with mass flow rate. For the same mass flow rate, the thermal efficiency increases with the decrease in the wire mesh pitch. The maximum daily average efficiency of air heater was 79.8% at 0.025 kg/s mass flow rate, 10 cm wire mesh gap and 9? collector inclination facing south. The highest collector efficiency was observed in solar air heaters with 10 cm wire mesh gap.


2014 ◽  
Vol 2014 ◽  
pp. 1-18 ◽  
Author(s):  
Rajendra Karwa ◽  
Shweta Baghel

The paper presents results of an analysis carried out using a mathematical model to find the effect of the uncertainties, variations, and tolerances in design and ambient parameters on the thermohydraulic performance of flat plate solar air heater. Analysis shows that, for the range of flow rates considered, a duct height of 10 mm is preferred from the thermohydraulic consideration. The thermal efficiency changes by about 2.6% on variation in the wind heat transfer coefficient, ±5 K variation in sky temperature affects the efficiency by about ±1.3%, and solar insolation variation from 500 to 1000 Wm−2 affects the efficiency by about −1.5 to 1.3% at the lowest flow rate of 0.01 kgs−1 m−2 of the absorber plate with black paint. In general, these effects reduce with increase in flow rate and are lower for collector with selective coating on the absorber plate surface. The tolerances in the duct height and absorber plate emissivity should be small while positive tolerance of 3° in the collector slope for winter operation and ±3° for year round operation, and a positive tolerance for the gap between the absorber plate and glass cover at nominal value of 40 mm are recommended.


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