11 research outputs found
Characteristics of Different Systems for the Solar Drying of Crops
Solar dryers are used to enable the preservation of agricultural crops, food processing industries for
dehydration of fruits and vegetables, fish and meat drying, dairy industries for production of milk powder,
seasoning of wood and timber, textile industries for drying of textile materials. The fundamental concepts and
contexts of their use to dry crops is discussed in the chapter. It is shown that solar drying is the outcome of
complex interactions particular between the intensity and duration of solar energy, the prevailing ambient
relative humidity and temperature, the characteristics of the particular crop and its pre-preparation and the
design and operation of the solar dryer
A Comparison of the Environmental Impact of Solar Power Generation Using Multicrystalline Silicon and Thin Film of Amorphous Silicon Solar Cells: Case Study in Thailand
This paper studies the environmental impact of two different forms of solar power generation in Thailand â that of multicrystalline silicon solar cells, and that of thin film amorphous silicon solar cells. It takes as its study two of the largest solar cell power plants of their kind in Thailand; a multicrystalline silicon plant in the north (generating 90 MW) and a thin film amorphous silicon plant in the centre (generating 55 MW). The Life Cycle Assessment tool (LCA) was used to assess the environmental impact of each stage of the process, from the manufacture of the cells, through to their transportation, installation and eventual recycling. The functional unit of the study was the generation of 1 kWh of power transmitted and distributed by the Electricity Generating Authority of Thailand (EGAT) and Provincial Electricity Authority (PEA). The environmental impact results were calculated in terms of eco-points (Pt) per functional unit of 1 kWh. The characterised data for 1 kWh of solar power generation was then compared with data for 1 kWh of combined cycle and thermal power generation (both in Thailand), using the same set of characterisation factors. After analyzing the results, both forms of solar power energy generation were found to impact upon the studied categories of Human Health, Ecosystem Quality and Resource Depletion, whilst also highlighting the importance of the solar cell module recycling process in decreasing the overall environmental impact. When the two solar cell technologies were compared, the overall impact of the multicrystalline silicon solar cell was found to be higher than that of the thin film amorphous silicon solar cell. Furthermore, when assessing the overall impact against non-renewable power generating technologies such as combined cycle and thermal power generation, the thin film amorphous silicon solar cells were found to have the lowest environmental impact of all technologies studied
Phase Change Material Coating on Autoclaved Aerated Lightweight Concrete for Cooling Load Reduction
This work is focused on enhancing the thermal effectiveness of autoclaved aerated concrete (AAC) by the application of phase change material (PCM) as a coating. The dynamics of heat transfer and the cooling load of air conditioning system in the two tested houses with different wall materials (AAC and AAC with PCM coating) were investigated. The work demonstrated that by coating phase change material onto the exterior surface of the building materials a significant increase in the thermal effectiveness of the building materials was achieved and determined by comparing the lower interior surface temperature, heat flux evolution and room temperature. The increase in thermal effectiveness was applied to the AAC. It was demonstrated that the cooling load and power consumption of air conditioning system in buildings using the wall-PCM coating combination can be reduced variously by about 25 %
Development and Characterization of Composite Desiccant Impregnated with LiCl for Thermoelectric Dehumidifier (TED)
Aqueous salt solutions (LiCl) were impregnated into a porous host matrix to create composite desiccant materials (silica gel). The authors of this paper fabricated and analyzed composite desiccant-coated aluminum sheets (DCAS) with varying LiCl mass concentrations. Nitrogen sorption results revealed that the Brunauer–Emmett–Teller (BET) surface area and pore volume of the composite desiccant-coated aluminum sheets decreased. Furthermore, composite DCAS had lower nitrogen sorption than silica-gel-coated aluminum sheets (SGCAS). According to the results, the composite DCAS had the highest thermal conductivity, measuring 6.1 Wm−1 K−1, doubling that of the SGCAS. For evaluating sorption kinetics, the linear driving force model (LDF) was used, and composite DCAS showed greater dynamic sorption quantities and sorption rate coefficients than SGCAS. Furthermore, three different moisture sorption isotherm models were used to fit the experimental results: the Brunauer–Emmett–Teller (BET) model, the Guggenheim–Anderson–Boer (GAB) model, and the double log polynomial (DLP) model. The DLP model was shown to be the best model for predicting the moisture sorption isotherms of DCAS. Additionally, the composite desiccant-coated heat sink (DCHS) of the thermoelectric dehumidifier (TED) was evaluated and compared to silica gel in terms of dehumidification capacity. According to the findings, the outlet air humidity ratio of the composite DCHS reached a minimum of 10.23 g kg−1, and the dehumidification capacity was 0.117 kg h−1 when the input electrical voltage was kept at 9 V
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āļāļēāļāļ§āļīāļāļąāļĒāļāļĩāđāļĄāļĩāļ§āļąāļāļāļļāļāļĢāļ°āļŠāļāļāđāđāļāļ·āđāļāļĻāļķāļāļĐāļēāļāļĢāļ°āļŠāļīāļāļāļīāļ āļēāļāļāļēāļĢāļāļģāļāļēāļāđāļāļ·āđāļāļāļāđāļāļāļāļāļĢāļ°āļāļāļāļąāļāđāļāđāļāļāļ§āļēāļĄāđāļĒāđāļāļāđāļ§āļĒāļŠāļēāļĢāđāļāļĨāļĩāđāļĒāļāļŠāļāļēāļāļ°āļŠāļģāļŦāļĢāļąāļāļāļēāļĢāļāļĢāļąāļāļāļēāļāļēāļĻ āđāļāļĒāļāļģāļĢāļ°āļāļāļāļąāļāđāļāđāļāļāļ§āļēāļĄāđāļĒāđāļāļāļģāļāļēāļāļĢāđāļ§āļĄāļāļąāļāļĢāļ°āļāļāļāļģāļāļ§āļēāļĄāđāļĒāđāļāļāļāļēāļ 11,601 āļāļĩāļāļĩāļĒāļđāļāđāļāļāļąāđāļ§āđāļĄāļ āļāļĩāđāļāļ§āļēāļĄāļāļĩāđāđāļāļāđāļē 50 āđāļŪāļīāļĢāļāļāđ āđāļāļŦāđāļāļāļāļāļīāļāļąāļāļīāļāļēāļĢāļāļĩāđāđāļāđāļĢāļąāļāļĄāļēāļāļĢāļāļēāļ ISO 17025 āļāļĢāļīāļĐāļąāļ āļāļīāļāđāļ§āđāļŠāđ (āļāļĢāļ°āđāļāļĻāđāļāļĒ) āļāļģāļāļąāļ āđāļāļ·āđāļāļāļāļŠāļāļāļāļĢāļ°āļŠāļīāļāļāļīāļ āļēāļāđāļāļāļēāļĢāļāļąāļāđāļāđāļāļāļ§āļēāļĄāđāļĒāđāļāļāļāļāļĢāļ°āļāļ āļāļēāļāļāļĨāļāļēāļĢāļāļāļŠāļāļāļāļāļ§āđāļēāđāļāļāļĢāļ°āļāļ§āļāļāļēāļĢāļāļĢāļ°āļāļļāļāļ§āļēāļĄāđāļĒāđāļāļāļāļāđāļāļĢāļ·āđāļāļāļāļąāļāđāļāđāļāļāļ§āļēāļĄāđāļĒāđāļ āđāļāđāļĢāļ°āļĒāļ°āđāļ§āļĨāļēāđāļāļĨāļĩāđāļĒ 45 āļāļēāļāļĩ āļŠāļēāļĄāļēāļĢāļāļāļģāđāļŦāđāļŠāļēāļĢāđāļāļĨāļĩāđāļĒāļāļŠāļāļēāļāļ°āđāļĒāđāļāļāļąāļ§āļĨāļāđāļāđāļāļļāļāļŦāļ āļđāļĄāļī -3.42 āļāļāļĻāļēāđāļāļĨāđāļāļĩāļĒāļŠ āļŠāļģāļŦāļĢāļąāļāļāļēāļĢāļāļāļŠāļāļāļāļĢāļ°āļāļ§āļāļāļēāļĢāļāļēāļĒāļāļ§āļēāļĄāđāļĒāđāļāļāļāļāđāļāļĢāļ·āđāļāļāļāļąāļāđāļāđāļāļāļ§āļēāļĄāđāļĒāđāļ āđāļāļĒāļāļ§āļāļāļļāļĄāļāļēāļāļēāļĻāļāļĩāđāđāļŦāļĨāļāđāļēāļāđāļŦāđāļĄāļĩāļāļļāļāļŦāļ āļđāļĄāļīāļāļĒāļđāđāļāļĩāđ 30 āļāļāļĻāļēāđāļāļĨāđāļāļĩāļĒāļŠ āļāļĩāđāļāļ§āļēāļĄāđāļĢāđāļ§āļĨāļĄāđāļāļĨāļĩāđāļĒ 2.30 āđāļĄāļāļĢāļāđāļāļ§āļīāļāļēāļāļĩ āļāļāļ§āđāļēāļŠāļēāļĄāļēāļĢāļāļĨāļāļāļļāļāļŦāļ āļđāļĄāļīāļāļēāļāļēāļĻāļĨāļāđāļāđāļŠāļđāļāļŠāļļāļ 10.37 āļāļāļĻāļēāđāļāļĨāđāļāļĩāļĒāļŠ āļāļīāļāđāļāđāļāļāđāļēāđāļāļĨāļĩāđāļĒāļāļĨāļāđāļēāļāļāļĢāļ°āļĄāļēāļ 3.90 āļāļāļĻāļēāđāļāļĨāđāļāļĩāļĒāļŠ āļāļķāđāļāļĢāļ°āļāļāļāļ°āļŦāļĒāļļāļāļāļēāļĒāļāļ§āļēāļĄāđāļĒāđāļ āđāļĄāļ·āđāļāļāļļāļāļŦāļ āļđāļĄāļīāļŠāļēāļĢāđāļāļĨāļĩāđāļĒāļāļŠāļāļēāļāļ°āđāļāđāļēāļāļąāļ 30 āļāļāļĻāļēāđāļāļĨāđāļāļĩāļĒāļŠ āđāļāļĒāđāļāđāļĢāļ°āļĒāļ°āđāļ§āļĨāļēāļāļĢāļ°āļĄāļēāļ 30 āļāļēāļāļĩ āđāļĨāļ°āļĄāļĩāļāļĢāļ°āļŠāļīāļāļāļīāļ āļēāļāļāļēāļĢāļāļąāļāđāļāđāļāļāļ§āļēāļĄāđāļĒāđāļāļāļĒāļđāđāļāļĩāđāļĢāđāļāļĒāļĨāļ° 67.91 āļāļīāļāđāļāđāļāļāļĢāļīāļĄāļēāļāļāļĨāļąāļāļāļēāļāđāļāļĨāļĩāđāļĒ 2,910.12 āļāļĩāļāļĩāļĒāļđāļāđāļāļāļąāđāļ§āđāļĄāļ āļāļąāļāļāļąāđāļāļĢāļ°āļāļāļāļąāļāđāļāđāļāļāļ§āļēāļĄāđāļĒāđāļāļĢāđāļ§āļĄāļāļąāļāļŠāļēāļĢāđāļāļĨāļĩāđāļĒāļāļŠāļāļēāļāļ°āļŠāļēāļĄāļēāļĢāļāļāļģāļĄāļēāđāļāđāđāļāļāļēāļĢāļāļĢāļąāļāļāļēāļāļēāļĻāļ āļēāļĒāđāļāļāļĢāļāļāļāļēāļāļēāļĢāļāļāļāļāļĢāļĩāļāļĄāļ§āļĨāđāļāļēāđāļāđ āđāļĨāļ°āļāļ°āļāļģāļāļēāļĢāļĻāļķāļāļĐāļēāļāļ§āļēāļĄāđāļāđāļāđāļāđāļāđāļāļāļāļĢāļ°āļāļāļāļąāļāđāļāđāļāļāļ§āļēāļĄāđāļĒāđāļāļĢāđāļ§āļĄāļāļąāļāļŠāļēāļĢāđāļāļĨāļĩāđāļĒāļāļŠāļāļēāļāļ°āđāļāļĒāđāļāđāđāļŦāļĨāđāļāļāļĨāļąāļāļāļēāļāļāļēāļĢāļĢāļ°āļāļāđāļāļĨāļĨāđāđāļŠāļāļāļēāļāļīāļāļĒāđāđāļāļāļāļŠāļĄāļāļŠāļēāļāđāļāđāđāļāļāļāļēāļāļThe objective of this study was to investigate the efficiency of the basic performance of cold storage system using phase change material (PCM-CSS) for air conditioning. The cold storage system working with the refrigerator system of 11,601 Btu/hr. at an electrical frequency of 50 Hz was tested in a laboratory certified by ISO 17025, Bitwise (Thailand) Co., Ltd. The results showed that the cooling charging process of the cold storage unit at an average of 45 min for the phase change material (PCM) to cool down to the temperature of â3.42°C. The cold discharging process of PCM-CSS was tested by controlling the airflow at the temperature of 30°C and at the average wind speed of 2.30 m/s. It was found that the reduction of the air temperature was at the maximum of 10.37°C with the average difference of 3.90°C. The discharging process would stop when the temperature of PCM was 30°C which took around 30 minutes. This revealed that the cold storage efficiency was 67.91% and the average energy of 2,910.12 Btu/hr Therefore, the PCM-CSS can be used for air conditioning in building with lightweight concrete walls. There is a possibility to study the efficiency of cold storage system and phase change materials using the photovoltaic hybrid system in the future
āļĢāļ°āļāļāļāļąāļāđāļāđāļāļāļ§āļēāļĄāđāļĒāđāļāđāļāļāļēāļāļēāļĢāđāļāļāļāļāļāļāļĢāļĩāļāļĄāļ§āļĨāđāļāļēāļĢāđāļ§āļĄāļāļąāļāļŠāļēāļĢāđāļāļĨāļĩāđāļĒāļāļŠāļāļēāļāļ°Cooling Storage System in Lightweight Concrete Building with Phase Change Material
āļāļēāļāļ§āļīāļāļąāļĒāļāļĩāđāļĄāļĩāđāļāļ§āļāļīāļāđāļāļāļēāļĢāļĻāļķāļāļĐāļēāļāļāļāđāļāļāļĢāļ°āļāļāļāļąāļāđāļāđāļāļāļ§āļēāļĄāđāļĒāđāļāļāđāļ§āļĒāļŠāļēāļĢāđāļāļĨāļĩāđāļĒāļāļŠāļāļēāļāļ°āđāļāļĒāđāļāđāļāļĨāļąāļāļāļēāļāđāļāļāđāļēāļāļēāļāđāļāļāđāļāļĨāļĨāđāđāļŠāļāļāļēāļāļīāļāļĒāđ (āļŠāļģāļŦāļĢāļąāļāļāļĢāļąāļāļāļēāļāļēāļĻāđāļāļāđāļēāļāļāļĩāđāļāļĒāļđāđāļāļēāļĻāļąāļĒāļāļĩāđāļĄāļĩāļāļēāļĢāļāļĢāļąāļāļāļēāļāļēāļĻāđāļāļāđāļ§āļāđāļ§āļĨāļēāļāļĨāļēāļāļāļ·āļ) āđāļāļ·āđāļāđāļāđāļāđāļāļ§āļāļēāļāđāļāļāļēāļĢāļāļąāļāļāļē āļāļĢāļąāļāļāļĢāļļāļ āđāļĨāļ°āđāļāļīāđāļĄāļāļĢāļ°āļŠāļīāļāļāļīāļ āļēāļāļāļāļāļĢāļ°āļāļāļāļąāļāđāļāđāļāļāļ§āļēāļĄāđāļĒāđāļāđāļāđāļāļĢāļāļŠāļĢāđāļēāļāļāļēāļāļēāļĢ āđāļāļĒāļāļģāļāļēāļĢāļāļāļŠāļāļāļāļĢāļ°āļŠāļīāļāļāļīāļ āļēāļāļāļāļāļĢāļ°āļāļāļāļąāļāđāļāđāļāļāļ§āļēāļĄāđāļĒāđāļāļāđāļ§āļĒāļŠāļēāļĢāđāļāļĨāļĩāđāļĒāļāļŠāļāļēāļāļ°āļāļĢāļ°āđāļ āļ āļāļēāļĢāļēāļāļīāļ (āļāļļāļāļŦāļ āļđāļĄāļīāļŦāļĨāļāļĄāļĨāļ°āļĨāļēāļĒ 20 āļāļāļĻāļēāđāļāļĨāđāļāļĩāļĒāļŠ) āđāļāļāđāļ§āļāļāļēāļĢāļāļąāļāđāļāđāļāļāļ§āļēāļĄāđāļĒāđāļ 5 āļāļĢāļāļĩ (āļāļĩāđāļāļ§āļēāļĄāļāļĩāđāļāļāļĄāđāļāļĢāļŠāđāļāļāļĢāđ 90 70 60 50 āđāļĨāļ° 40 āđāļŪāļīāļĢāļāļāđ) āļāļāļ§āđāļēāļāļ§āļēāļĄāļāļĩāđāļāļĩāđāđāļŦāļĄāļēāļ°āļŠāļĄāļŠāļģāļŦāļĢāļąāļāļāļēāļĢāđāļāļāļ§āļēāļĄāđāļĒāđāļāđāļŦāđāļāļąāļāļŠāļēāļĢāđāļāļĨāļĩāđāļĒāļāļŠāļāļēāļāļ°āļāļĒāļđāđāļāļĩāđ 50 āđāļŪāļīāļĢāļāļāđ āđāļāļĒāļĄāļĩāļāđāļēāļŠāļĄāļĢāļĢāļāļāļ°āļāļēāļĢāļāļģāļāļ§āļēāļĄāđāļĒāđāļ (COP) āđāļĨāļ°āļāļąāļāļĢāļēāļŠāđāļ§āļāļāļĢāļ°āļŠāļīāļāļāļīāļ āļēāļāļāļĨāļąāļāļāļēāļ (EER) āļāļĒāļđāđāļāļĩāđ 3.09 āđāļĨāļ° 10.53 (Btu/hr.)/W āļāļīāļāđāļāđāļāļĢāđāļāļĒāļĨāļ°āļāļĢāļ°āļŠāļīāļāļāļīāļ āļēāļāđāļāļāļēāļĢāļāļąāļāđāļāđāļāļāļ§āļēāļĄāđāļĒāđāļāļāļāļāļĢāļ°āļāļāđāļāđāļēāļāļąāļ 7.03 āļāļēāļĢāđāļāđāļāļĨāļąāļāļāļēāļāđāļāļāđāļēāļāļēāļāļāļēāļĢāđāļāļāđāļēāļŠāđāļ§āļāļ āļđāļĄāļīāļ āļēāļāđāļāļĩāļĒāļāļāļĒāđāļēāļāđāļāļĩāļĒāļ§ āļĄāļĩāļāļĢāļīāļĄāļēāļāļāļēāļĢāđāļāđāļāļĨāļąāļāļāļēāļāđāļāļāđāļēāļāļĒāļđāđāļāļĩāđ 6.11 āļāļīāđāļĨāļ§āļąāļāļāđāļāļąāđāļ§āđāļĄāļ (āļŠāļģāļŦāļĢāļąāļāļāļēāļĢāļāļģāļāļ§āļēāļĄāđāļĒāđāļ 8 āļāļąāđāļ§āđāļĄāļ) āđāļāļĒāđāļāļāļĢāļāļĩāļāļĩāđāļĄāļĩāļāļēāļĢāđāļāđāļāļĨāļąāļāļāļēāļāđāļāļāđāļēāļĢāđāļ§āļĄāļāļąāļāđāļāļāđāļāļĨāļĨāđāđāļŠāļāļāļēāļāļīāļāļĒāđ āļāļģāđāļŦāđāļĢāļ°āļāļāļĄāļĩāļāļĢāļīāļĄāļēāļāļāļēāļĢāđāļāđāļāļĨāļąāļāļāļēāļāđāļāļāđāļēāļĨāļāļĨāļ āļāļĒāļđāđāļāļĩāđāļāļĢāļ°āļĄāļēāļ 1.13 āļāļīāđāļĨāļ§āļąāļāļāđāļāļąāđāļ§āđāļĄāļ āļāļīāļāđāļāđāļāļĢāđāļāļĒāļĨāļ°āļāļēāļĢāļāļĢāļ°āļŦāļĒāļąāļāđāļāđāļēāļāļąāļ 81.57 āļāļķāđāļāļŠāđāļ§āļāļāļĢāļ°āļāļāļāļāļāļāļĢāļ°āļāļāļāļĩāđāļĄāļĩāļāļēāļĢāđāļāđāļāļĨāļąāļāļāļēāļāđāļāļāđāļēāļĄāļēāļāļāļĩāđāļŠāļļāļāđāļāđāđāļāđ āļāļļāļāļāļāļĒāļĨāđāļĢāđāļāļāļ āļēāļĒāļāļāļāļāļēāļāļēāļĢ āļāļīāļāđāļāđāļāļĢāđāļāļĒāļĨāļ° 55The aim of this research is to study and design the Phase Change Material Cooling Storage System (PCM-CSS) by using Photovoltaic (PV) cell for night air conditioning in lightweight concrete buildings. The PCM-CSS was applied to improve the efficiency of cooling storage system for buildings. The efficiency of PCM-CSS and the energy consumption between using electricity power from the Provincial Electricity Authority (PEA) and PEA with PV were studied in the experiment. The melting point of paraffin was selected at 22 °C to store the coldness from refrigerant (R410A). The PCM-CSS processes consist of the charging and discharging. The frequency of compressor was varied in five cases for charging process, namely 90, 70, 60, 50, and 40 Hz. The result indicates that the 50 Hz is an appropriate frequency for cooling charging to PCM with 3.09 of COP, 10.53 (Btu/hr)/W of EER and 7.03% of ηC,Charg. Eventually, the result of the comparison on energy consumption between using electricity power from PEA and PEA with PV reveals the PCM-CSS using electricity power from PEA without PV is approximately 6.11 kWh (charging process for 8 hours.). On the other hand, the electricity power usage from PEA with PV can decrease the energy consumption by approximately 1.13 kWh or can be saved around 81.57% as compared with the electricity power usage from PEA only. The condensing unit of the PCM-CSS, accounting for 55% of the total consumption, represents the greatest segment of power consumption
Development and Characterization of Composite Desiccant Impregnated with LiCl for Thermoelectric Dehumidifier (TED)
Aqueous salt solutions (LiCl) were impregnated into a porous host matrix to create composite desiccant materials (silica gel). The authors of this paper fabricated and analyzed composite desiccant-coated aluminum sheets (DCAS) with varying LiCl mass concentrations. Nitrogen sorption results revealed that the BrunauerâEmmettâTeller (BET) surface area and pore volume of the composite desiccant-coated aluminum sheets decreased. Furthermore, composite DCAS had lower nitrogen sorption than silica-gel-coated aluminum sheets (SGCAS). According to the results, the composite DCAS had the highest thermal conductivity, measuring 6.1 Wmâ1 Kâ1, doubling that of the SGCAS. For evaluating sorption kinetics, the linear driving force model (LDF) was used, and composite DCAS showed greater dynamic sorption quantities and sorption rate coefficients than SGCAS. Furthermore, three different moisture sorption isotherm models were used to fit the experimental results: the BrunauerâEmmettâTeller (BET) model, the GuggenheimâAndersonâBoer (GAB) model, and the double log polynomial (DLP) model. The DLP model was shown to be the best model for predicting the moisture sorption isotherms of DCAS. Additionally, the composite desiccant-coated heat sink (DCHS) of the thermoelectric dehumidifier (TED) was evaluated and compared to silica gel in terms of dehumidification capacity. According to the findings, the outlet air humidity ratio of the composite DCHS reached a minimum of 10.23 g kgâ1, and the dehumidification capacity was 0.117 kg hâ1 when the input electrical voltage was kept at 9 V