scholarly journals Optimization of Solar CCHP Systems with Collector Enhanced by Porous Media and Nanofluid

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Navid Tonekaboni ◽  
Mahdi Feizbahr ◽  
Nima Tonekaboni ◽  
Guang-Jun Jiang ◽  
Hong-Xia Chen
Keyword(s):  
Porous Media ◽  
Maximum Energy ◽  
Exergy Efficiency ◽  
Solar Collectors ◽  
Efficiency Enhancement ◽  
Optimal Amount ◽  
Solar Systems ◽  
Energy And Exergy ◽  
Low Efficiency ◽  
Combined Cooling

The low efficiency of solar collectors can be mentioned as one of the problems in solar combined cooling, heating, and power (CCHP) cycles. For improving solar systems, nanofluid and porous media are used in solar collectors. One of the advantages of using porous media and nanoparticles is to absorb more energy under the same conditions. In this research, a solar combined cooling, heating, and power (SCCHP) system has been optimized by porous media and nanofluid for generating electricity, cooling, and heating of a 600 m2 building in a warm and dry region with average solar radiation of Ib = 820 w/m2 in Iran. In this paper, the optimal amount of nanofluid in porous materials has been calculated to the extent that no sediment is formed. In this study, solar collectors were enhanced with copper porous media (95% porosity) and CuO and Al2O3 nanofluids. 0.1%–0.6% of the nanofluids were added to water as working fluids; it is found that 0.5% of the nanofluids lead to the highest energy and exergy efficiency enhancement in solar collectors and SCCHP systems. Maximum energy and exergy efficiency of parabolic thermal collector (PTC) riches in this study are 74.19% and 32.6%, respectively. Figure 1 can be mentioned as a graphical abstract for accurately describing the cycle of solar CCHP.

Review on Solar Collector for Agricultural Produce

2018 ◽  
Vol 9 (1) ◽  
pp. 414 ◽  
Author(s):  
Ahmad Fudholi ◽  
Kamaruzzaman Sopian
Keyword(s):  
Solar Energy ◽  
Thermal Energy ◽  
Solar Collector ◽  
Energy Systems ◽  
Exergy Efficiency ◽  
Solar Collectors ◽  
Agricultural Produce ◽  
Essential Components ◽  
Energy And Exergy ◽  
Solar Air Collector

<span>Among the most important components of solar energy systems, solar collectors are devices that receive solar energy and convert it into thermal energy, as most essential components of solar dryer. This review presents description and previous work performed on performances of solar air collector for agricultural produce. In addition, various solar collectors are classified and described. Solar air collectors for drying application of agricultural produce are presented and summarize. The energy and exergy efficiency of the solar air collector ranges from 28% to 62% and from 30% to 57%, respectively. </span>

scholarly journals Energy and exergy efficiency of heat pipe evacuated tube solar collectors

2016 ◽  
Vol 20 (1) ◽  
pp. 327-335 ◽  
Author(s):  
Farzad Jafarkazemi ◽  
Emad Ahmadifard ◽  
Hossein Abdi
Keyword(s):  
Heat Pipe ◽  
Solar Collector ◽  
Theoretical Method ◽  
Exergy Efficiency ◽  
Inlet Temperature ◽  
Solar Collectors ◽  
Evacuated Tube Solar Collector ◽  
Energy And Exergy ◽  
Water Mass Flow Rate ◽  
Evacuated Tube

In this paper, a heat pipe evacuated tube solar collector has been investigated both theoretically and experimentally. A detailed theoretical method for energy and exergy analysis of the collector is provided. The method is also evaluated by experiments. The results showed a good agreement between the experiment and theory. Using the theoretical model, the effect of different parameters on the collector?s energy and exergy efficiency has been investigated. It is concluded that inlet water temperature, inlet water mass flow rate, the transmittance of tubes and absorptance of the absorber surface have a direct effect on the energy and exergy efficiency of the heat pipe evacuated tube solar collector. Increasing water inlet temperature in heat pipe evacuated solar collectors leads to a decrease in heat transfer rate between the heat pipe?s condenser and water.

scholarly journals Energy and exergy analysis of combined cooling and power system using variable mode adsorption chiller

2021 ◽  
Vol 294 ◽  
pp. 03002
Author(s):  
Ahmad A. Alsarayreh ◽  
Ayman Al-Maaitah ◽  
Menwer Attarakih ◽  
Hans-Jörg Bart
Keyword(s):  
Ambient Temperature ◽  
Waste Heat ◽  
Exergy Efficiency ◽  
Single Stage ◽  
Ambient Conditions ◽  
Adsorption Chiller ◽  
Energy And Exergy ◽  
Variable Mode ◽  
Combined Cooling ◽  
Mass Recovery

Adsorption cooling is a promising technology to recover low-temperature waste heat from a diesel genset. In this paper, an advanced adsorption chiller working in variable mode is proposed for the combined cooling and power cycle (CCP) to recover waste heat from the water jacket in the diesel genset. The chiller works on three modes based on the ambient temperature for better heat utilization. In this study, three modes were investigated: single-stage cycle mode, short-duration, and medium-duration mass recovery modes. The results show that the energy and exergy efficiency for a single-stage cycle mode is higher at an ambient temperature lower than 35 °C . In comparison, the mass recovery mode has a higher energy and exergy efficiency at an ambient temperature higher than 35 °C. The annual energy and exergy efficiency for the CCP was investigated when the chiller works with variable modes based on the ambient temperature under DUBAI weather conditions as a case study. The results show an improvement of 14.7% and 14% of the energy and exergy efficiency, respectively, for CCP with a variable mode adsorption chiller compared to diesel genset alone. The results also show the CCP with variable mode adsorption chiller has a slight improvement on both energy and exergy efficiency compared to CCP with a single-stage adsorption chiller at the same ambient conditions.

Indirect Solar Cooking Using a Novel Fresnel Lens and Determination of its Energy and Exergy Efficiencies

2014 ◽  
Author(s):  
Md. Didarul Islam ◽  
Fawzi Banat ◽  
Priyabrata Pal ◽  
Obaid Younas
Keyword(s):  
Energy Efficiency ◽  
High Temperature ◽  
Temperature Difference ◽  
Fresnel Lens ◽  
Maximum Energy ◽  
Exergy Efficiency ◽  
Cylindrical Vessel ◽  
Energy And Exergy ◽  
High Temperature Steam

This paper proposes a new kind of system for effective indirect solar cooking by utilizing a novel Fresnel lens. A semi-cylindrical vessel (solar boiler) for producing steam and a jacketed cooker was designed, fabricated and tested experimentally for cooking applications. The solar boiler produced high temperature steam of 146°C and pressure of 3.15 barg which was used for cooking purposes. The international standard for evaluating cooker performance was implemented on this system and heating power was determined to be 51.2 Watt at a temperature difference of 50°C. The maximum energy and exergy efficiencies for boiler were found to be 30.18 % and 2.86%, respectively. This represents a 92% increment in energy efficiency and 128.8% increment in exergy efficiency as compared to solar parabolic cookers. The maximum energy efficiency of 5.02% and maximum exergy efficiency of 0.378% were achieved in this cooking system.

scholarly journals Correction to: A comparative energy and exergy efficiency study of hemispherical and single-slope solar stills

2021 ◽  
Author(s):  
Mohammed El Hadi Attia ◽  
Abd Elnaby Kabeel ◽  
Abdelkader Bellila ◽  
Athikesavan Muthu Manokar ◽  
Ravishankar Sathyamurthy ◽  
...  
Keyword(s):  
Exergy Efficiency ◽  
Energy And Exergy

scholarly journals Energetic and exergetic analysis of a convective drier: A case study of potato drying process

2020 ◽  
Vol 5 (1) ◽  
pp. 563-572
Author(s):  
Iman Golpour ◽  
Mohammad Kaveh ◽  
Reza Amiri Chayjan ◽  
Raquel P. F. Guiné
Keyword(s):  
Energy Consumption ◽  
Research Work ◽  
Specific Energy Consumption ◽  
Exergy Efficiency ◽  
Operating Conditions ◽  
Energy Utilization ◽  
Convective Drying ◽  
Drying Time ◽  
Energy And Exergy ◽  
Exergy Losses

AbstractThis research work focused on the evaluation of energy and exergy in the convective drying of potato slices. Experiments were conducted at four air temperatures (40, 50, 60 and 70°C) and three air velocities (0.5, 1.0 and 1.5 m/s) in a convective dryer, with circulating heated air. Freshly harvested potatoes with initial moisture content (MC) of 79.9% wet basis were used in this research. The influence of temperature and air velocity was investigated in terms of energy and exergy (energy utilization [EU], energy utilization ratio [EUR], exergy losses and exergy efficiency). The calculations for energy and exergy were based on the first and second laws of thermodynamics. Results indicated that EU, EUR and exergy losses decreased along drying time, while exergy efficiency increased. The specific energy consumption (SEC) varied from 1.94 × 105 to 3.14 × 105 kJ/kg. The exergy loss varied in the range of 0.006 to 0.036 kJ/s and the maximum exergy efficiency obtained was 85.85% at 70°C and 0.5 m/s, while minimum exergy efficiency was 57.07% at 40°C and 1.5 m/s. Moreover, the values of exergetic improvement potential (IP) rate changed between 0.0016 and 0.0046 kJ/s and the highest value occurred for drying at 70°C and 1.5 m/s, whereas the lowest value was for 70°C and 0.5 m/s. As a result, this knowledge will allow the optimization of convective dryers, when operating for the drying of this food product or others, as well as choosing the most appropriate operating conditions that cause the reduction of energy consumption, irreversibilities and losses in the industrial convective drying processes.

A comparative energy and exergy efficiency study of hemispherical and single-slope solar stills

2021 ◽  
Author(s):  
Mohammed El Hadi Attia ◽  
Abd Elnaby Kabeel ◽  
Abdelkader Bellila ◽  
Athikesavan Muthu Manokar ◽  
Ravishankar Sathyamurthy ◽  
...  
Keyword(s):  
Exergy Efficiency ◽  
Energy And Exergy
Sign in / Sign up

Export Citation Format

Share Document