scholarly journals KINERJA KOLEKTOR TIPE PLAT DATAR PADA MESIN PENDINGIN ADSORPSI TENAGA SURYA DI KOTA MEDAN

2018 ◽  
Vol 7 (2) ◽  
pp. 94
Author(s):  
Tulus Burhanuddin Sitorus
Keyword(s):  
Solar Collector ◽  
Statistical Study ◽  
Cooling System ◽  
Weather Conditions ◽  
Coefficient Of Performance ◽  
Total Solar Radiation ◽  
Collector Efficiency ◽  
Powder Activated Carbon ◽  
Adsorption Cooling System ◽  
Flat Plate Collector

The performance of a flat plate collector on adsorption refrigerator driven by the solar collector was investigated in the present work. Based on a study conducted no researcher studies the performance of solar collectors used in adsorption cooling system. The adsorbent used in the collector was 20 kg ordinary powder activated carbon of coconut shell produced in the Sumatera Utara province of Indonesia, 5 liters of methanol as adsorbate and 6 liters of water as the medium that was cooled. The experiments were carried out under varying weather conditions with total solar radiation about 12619-17807 kJ/m2/cycle in Medan city. The experimental results show that the values of collector efficiency obtained were about 52.11-53.92%. The values of coefficient of performance (COP) obtained were in the range of 0.0318-0.0449. The results of the statistical study suggest that the effect of the weather conditions on collector efficiency thereabout 96%.

scholarly journals System Design of Solar Absorption Cooling : A Case Study in Building of Engineering Physics Department UGM

KnE Energy ◽  
2015 ◽  
Vol 2 (2) ◽  
pp. 22
Author(s):  
Andang Widiharto ◽  
Didit Setyo Pamuji ◽  
Atik Nurul Laila ◽  
Fiki Rahmatika Salis ◽  
Luthfi Zharif ◽  
...  
Keyword(s):  
Global Warming ◽  
Solar Collector ◽  
Air Conditioning ◽  
Cooling System ◽  
Renewable Energy Sources ◽  
Coefficient Of Performance ◽  
Thermal Coefficient ◽  
Solar Absorption ◽  
Absorption Cooling ◽  
Solar Absorption Cooling

<p>Air conditioning (AC) is one of the most building’s energy consumer, included in building of Engineering Physisc’s Departement, Universitas Gadjah Mada (UGM). The declining of fossil fuel reserves and the increasing effects of global warming, forcing the world to switch to renewable energy sources. This paper discusses the design of solar absorption cooling system to replace conventional AC in seven lecture halls of Engineering Physic’s Departement, UGM. There are some steps that have been done to design the solar absorption cooling, i.e. do a study of the potential availability of solar energy, calculate the cooling loads, analyze the thermodynamic process of the system, determine the type of collector to be used and calculate area of solar collector needed. The thermal coefficient of performance (COP) of the system designed was about 0.84 which could use some types of flat plate solar collector with each area corresponding to each efficiency values. </p><p><strong>Keyword</strong> : Air conditioning; global warming; solar absorption cooling; solar collector</p>

Simulation and performance study of a two-bed adsorption cooling system operated with activated carbon-ethanol

2021 ◽  
pp. 095440622110420
Author(s):  
V Baiju ◽  
A Asif Sha ◽  
NK Mohammed Sajid ◽  
K Muhammedali Shafeeque
Keyword(s):  
Water Temperature ◽  
Performance Optimization ◽  
Cooling System ◽  
Cooling Water ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Cooling Power ◽  
Performance Study ◽  
Evaporator Temperature ◽  
Adsorption Cooling System

This paper presents the transient model of a two-bed adsorption cooling system performed in the SIMULINK platform. The inlet chilled water temperature in the evaporator, temperature of cooling water and hot water temperature of the adsorbent bed and its effect on systems coefficient of performance, refrigeration effect and specific cooling power have been studied and presented. It is observed that the systems coefficient of performance is 0.57 when the inlet hot water temperature about 80 °C. In this study, the optimum cooling power and systems coefficient of performance are also determined in terms of the phase time, shifting duration and hot water inflow temperature. The results indicates that the cooling water and hot water inlet temperatures significantly affects the coefficient of performance, specific cooling power and cooling power of the system. The effect of mass flow rate on the cooler efficiency is also presented. A two bed adsorption system of capacity 13.5 kW having an evaporator and condenser temperatures of 6°C and 28°C, respectively, are considered for the present investigation. The adsorbent mass considered is 45 kg with a shifting duration of 20 sec. The result of this study gives the basis for performance optimization of a practical continuous operating vapour adsorption cooler.

An Analytical Examination of Methods for Improving the Performance of Desiccant Cooling Systems

1991 ◽  
Vol 113 (3) ◽  
pp. 157-163 ◽  
Author(s):  
R. K. Collier ◽  
B. M. Cohen
Keyword(s):  
Heat Capacity ◽  
Solar Collector ◽  
Air Conditioning ◽  
Cooling System ◽  
Coefficient Of Performance ◽  
Cooling Systems ◽  
Transfer Processes ◽  
Air Stream ◽  
Wave Nature ◽  
Mass Transfer Processes

The conventional Pennington Cycle desiccant cooling system offers a clear opportunity for heat-actuated air conditioning. However, efforts to translate this opportunity into commercially viable hardware have not been successful. The performance of the hardware has been inadequate, resulting in excessive solar collector requirements or, in the case of gas-fired equipment, uneconomical use of natural gas. Two methods for improving the coefficient of performance (COP) of these systems are: (1) the addition of inert heat capacity to the desiccant matrix, and (2) “staging” the regeneration air stream. An analysis is presented in this paper which explains the benefits and drawbacks of these methods based upon the wave nature of the heat and mass transfer processes occurring within the desiccant bed. The results indicate that the best overall system performance is obtained by staging the regeneration process while minimizing the amount of inert heat capacity.

scholarly journals Study and Analysis by Numerical Simulation of a Solar Continuous Adsorption Chiller

2015 ◽  
Vol 773-774 ◽  
pp. 605-609
Author(s):  
Rabah Gomri ◽  
Billel Mebarki
Keyword(s):  
Solar Energy ◽  
Cooling System ◽  
Recovery Process ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Solar Collectors ◽  
Adsorption Refrigeration ◽  
Continuous Adsorption ◽  
Adsorption Cooling System ◽  
Mass Recovery

Environment and energy problems over the world have motivated researchers to develop energy systems more sustainable, having as one of the possible alternative the use of solar energy as source for cooling systems. Adsorption refrigeration systems are regarded as environmentally friendly alternatives to conventional vapour compression refrigeration systems, since they can use refrigerants that do not contribute to ozone layer depletion and global warming. In this paper a performance comparison between a solar continuous adsorption cooling system without mass recovery process and solar continuous adsorption cooling system with mass recovery process is carried out. Silica-Gel as adsorbent and water as refrigerant are selected. The results show that the adsorption refrigeration machine driven by solar energy can operate effectively during four months and is able to produce cold continuously along the 24 hours of the day. The importance of the mass recovery is proved in this study by increasing the coefficient of performance and the cooling capacity produced. For the same cooling capacity produced, the required number of solar collectors with mass recovery system is lower than the required number of solar collectors in the case of the refrigeration unit without mass recovery. For the same cooling capacity the system with mass recovery process allowed lower generation temperature.

scholarly journals Experimental Evaluation of a Flat Plate Solar Collector Under Hail City Climate

2018 ◽  
Vol 8 (2) ◽  
pp. 2750-2754
Author(s):  
N. Ben Khedher
Keyword(s):  
Flat Plate ◽  
Flow Rate ◽  
Solar Collector ◽  
Weather Conditions ◽  
Water Heater ◽  
Optimum Flow Rate ◽  
Water Heaters ◽  
Flat Plate Solar Collector ◽  
Flat Plate Collector ◽  
Solar Water Heaters

Flat plate solar water heaters are widely used for water heating in low-temperature residential applications. In this paper the thermal performance of a solar flat plate water heater under Hail weather conditions (latitude 27°52΄N longitude ‎41°69΄E) was experimentally investigated. Fluid was circulated through the imbedded copper tubes in the flat plate collector and inlet and outlet temperatures of the fluid were noted at five minute intervals. The experimental-time was between 9:00AM-15:00PM. A study was carried out experimentally to present the efficiency curves of a flat plate solar collector at different flow rates. ASHRAE standard 93-2003 was followed for calculation of instantaneous efficiency of solar collector. Result shows that the flow rate of the circulating fluid highly influence the thermal efficiency of the solar collector. Optimum flow rate of 2.5L/min leads to maximum collector efficiency.

Simulation Study of the Heat and Mass Recovery on the Performance of Adsorption Cooling Systems

2014 ◽  
Author(s):  
K. C. Chan ◽  
C. Y. Tso ◽  
Christopher Y. H. Chao
Keyword(s):  
System Performance ◽  
Heat Recovery ◽  
Cooling System ◽  
Coefficient Of Performance ◽  
Cooling Power ◽  
Cooling Systems ◽  
Heating And Cooling ◽  
Adsorption Cooling System ◽  
Heat And Mass Recovery ◽  
Mass Recovery

In this study, simulation was conducted to investigate the effect of mass recovery, heat recovery, pre-heating and pre-cooling time on the system performance of a double-bed adsorption cooling system. Pressures of different system components were considered in the simulation. The adsorbent-adsorbate pair used was silica-gel and water. The heating and cooling temperatures were selected to be 85°C and 27°C respectively. Both the adsorption and desorption phase times were set at 15 minutes. The coefficient of performance (COP) and specific cooling power (SCP) were used to quantify the performance of the system. From the simulation, the basic cycle provided COP and SCP of 0.20 and 40.9W/kg respectively. By conducting heat recovery for 120 seconds, the system COP was largely increased by 99% to 0.40 compared to the basic cycle. The SCP was also increased to 42.3W/kg. Mass recovery, however, did not have too much effect on the system performance. The COP and SCP only increased by 4.5% and 3.9% respectively when conducting mass recovery for 4.7 seconds. For conducting heat and mass recovery, the COP and SCP were increased to 0.36 and 44.68W/kg, respectively. Pre-heating and pre-cooling can also be beneficial in improving both COP and SCP. The COP and SCP were increased by 14.5% and 10.1% respectively, to 0.23 and 45.0W/kg by conducting pre-heating and pre-cooling for 50.3 seconds. The combinations of these processes were also studied. It is suggested heat and mass recovery then pre-heating and pre-cooling should be conducted to improve COP and SCP. The improvements showed 31.2% for COP, increasing to 0.27, and 11.9% for SCP, increasing to 45.7W/kg.

Performance of Thermoelectric Based Regenerative Adsorption Cooling System for Harsh Environment

2009 ◽  
Author(s):  
Ashish Sinha ◽  
Yogendra Joshi
Keyword(s):  
Heat Flow ◽  
Cycle Time ◽  
Cooling System ◽  
Fixed Time ◽  
Coefficient Of Performance ◽  
Thermoelectric Device ◽  
Harsh Environment ◽  
Evaporator Temperature ◽  
Heat Regeneration ◽  
Adsorption Cooling System

Performance of a cooling system designed for thermal management of harsh environment electronics has been presented. The system is based on regenerative adsorption-desorption cycle and mainly comprises of two beds with zeolite-water as adsorbent-adsorbate pair, a condenser and an evaporator. Heat regeneration was achieved by a thermoelectric (TE) device placed in between the zeolite beds. Use of a thermoelectric device for heat transfer in between beds allows for miniaturization of usually bulky adsorption cooling systems. This also provides a cooling system with nearly no moving parts, hence suitable for harsh environment electronic cooling applications. Zeolite beds alternately carry out adsorption and desorption depending on the direction of heat flow in between them. Direction of heat flow is governed by the polarity of voltage applied across the TE device. Polarity is switched at fixed time intervals that determine the cycle time. Tests were carried out during which the condenser temperature hovered around 165 °C, heat load was up to 5W, the cycle time kept close to 12 minutes and the targeted evaporator temperature was 140 °C. System was analyzed in terms of the extent of cooling below the heat rejection ambient temperature of 160 °C and coefficient of performance. A COP of 0.2 was obtained. The study could be used to extend the working envelopes of existing electronics towards hotter surroundings. A mathematical model was also prepared and the experimental results have been compared with the simulations.

Energy and exergy analyses of LiBr/H2O absorption cooling system having recto-trapezoidal profile absorber plate

2020 ◽  
pp. 095440622095969
Author(s):  
Rahul Roy ◽  
Balaram Kundu
Keyword(s):  
Solar Collector ◽  
Cooling System ◽  
Coefficient Of Performance ◽  
Inlet Temperature ◽  
Absorption Refrigeration ◽  
Exergetic Efficiency ◽  
Absorber Plate ◽  
Energy And Exergy ◽  
Trapezoidal Profile ◽  
Exergy Analyses

This paper develops a theoretical model for energy and exergy analyses of a solar-powered Lithium-water absorption refrigeration system using a recto-trapezoidal flat plate solar collector. The effect of collector fluid inlet temperature is to examine the overall performance of the solar collector and the vapour absorption system for a wide range of design variables. The parameters computed are energy and exergy efficiencies of the solar collector plate, coefficient of performance, cooling efficiency, exergy destruction rates, thermal exergy loss rates, irreversibility, and exergetic efficiency of the absorption refrigeration cycle. The simulation results indicate that there exists an optimum inlet temperature of collector fluid for the maximum system coefficient of performance and exergetic efficiency. When the cooling system runs at this temperature, the absorber plate volume attains a minimum value. Furthermore, the performance results are significantly better when a higher absorber plate thickness parameter is for the recto-trapezoidal profile. Finally, a comparative study analyzes the collector performance parameters of an absorber plate having rectangular, triangular, or trapezoidal profile by selecting their respective parameters of geometries. When an additional constraint imposes on the plate volume, it found that using a recto-trapezoidal profile instead of a rectangular profile saves at least 30% or more collector material, and also it may have better performance than a triangular or trapezoidal profile.

Improvement of COP with Heat Recovery Scheme for Solar Adsorption Cooling System

2018 ◽  
Vol 26 (02) ◽  
pp. 1850016 ◽  
Author(s):  
K. M. Ariful Kabir ◽  
Rifat A. Rouf ◽  
M. M. A. Sarker ◽  
K. C. Amanul Alam ◽  
Bidyut B. Saha
Keyword(s):  
Heat Transfer ◽  
Heat Recovery ◽  
Cooling System ◽  
Continuous System ◽  
Recovery Process ◽  
Coefficient Of Performance ◽  
Heat Transfer Fluid ◽  
Adsorption Refrigeration ◽  
Adsorption Chiller ◽  
Adsorption Cooling System

Heat recovery ensures optimum usage of the collected energy, and thus, minimizes heat loss for a solar adsorption chiller. Two-bed adsorption chiller with conventional single stage, run by direct solar coupling with heat recovery, has been studied mathematically. In a heat recovery adsorption refrigeration system, to facilitate heat transfer, heat transfer fluid is distributed between two adsorbers maintaining the same mass flow rate. There is no mass transfer between system components during this phase. It is a semi-continuous system performed between two adsorption beds. After completion of desorption/condensation mode, heat transfer fluid is allowed to circulate between the heated desorber and the cooled adsorber. This process distributes some heat of the desorption bed to the adsorber preparing it for the next preheating mode where heat transfer between them is done adiabatically. Consequently, the performance has been checked and a satisfactory increase in the Coefficient of Performance (COP) (approximately 15%) has been detected in the calculated results for the heat recovery operation. It is also observed that the heat recovery process enhances the working hour and overall performances of the solar heat driven adsorption chiller.

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