Description of a smart auto-optimised district trigeneration network (heating, cooling & power) based on Anaerobic Digestion and solar energy in green cities

2014 ◽  
Author(s):  
Skoufoglou ◽  
M.B. Gusta
Keyword(s):  
Anaerobic Digestion ◽  
Solar Energy ◽  
Cooling Power ◽  
Green Cities

Modeling of a Refrigerator in Disaster Vehicle, Using Solar Energy and Engine Exhaust Gases Heat

2016 ◽  
Vol 138 (5) ◽  
Author(s):  
Shahram Derakhshan ◽  
Alireza Yazdani
Keyword(s):  
Solar Energy ◽  
Electrical Energy ◽  
Coefficient Of Performance ◽  
Cooling Power ◽  
Refrigeration Cycle ◽  
Adsorption Refrigeration ◽  
Engine Exhaust ◽  
Exhaust Gases ◽  
Exhaust Heat ◽  
Heat Adsorption

In critical situations such as floods and earthquakes, the relief forces require a refrigeration for pharmaceuticals and vaccines, which could operate without an electrical energy and the alternative energies, such as solar energy, engine exhaust gases heat, and wind energy. In this paper, a refrigeration cycle has been modeled as an adsorption refrigeration cycle with an activated carbon/methanol as adsorbent/adsorbate pair and two sources of energy—solar energy and engine exhaust gases heat. The solar cycle had a collector with area of 1 m2 and the exhaust gas cycle included a heat exchanger with 100 °C temperature difference between inlet and outlet gases. The temperature profile in adsorbent bed, evaporator, and condenser was obtained from modeling. Moreover, the pressure profile, overall heat transfer coefficient of collector and adsorbent bed, concentration, and the solar radiation were reported. Results represented the coefficient of performance (COP) of 0.55, 0.2, and 0.56 for complete system, solar adsorption refrigeration, and exhaust heat adsorption refrigeration, respectively. In addition, exhaust heat adsorption refrigeration has a value of 2.48 of specific cooling power (SCP). These results bring out a good performance of the proposed model in the climate of Iran.

Design of the Solar Energy-Heated Biogas Digester

2014 ◽  
Vol 953-954 ◽  
pp. 103-106
Author(s):  
Jin Yang Li ◽  
Jian Li ◽  
Qing Yu Liu ◽  
Hao Zheng
Keyword(s):  
Anaerobic Digestion ◽  
Solar Energy ◽  
Production Rate ◽  
Northern China ◽  
Gas Production ◽  
Raw Material ◽  
Solar Thermal ◽  
Biogas Slurry ◽  
Optimum Temperature ◽  
Working Principle

Heating biogas digester is essential in northern China, especially during the winter. Solar energy-heated biogas digester is a facility that radiates heat by the solar thermal, which maintains the temperature of the biogas digester. The working principle behind this facility is the division of the traditional biogas digester into three parts, namely, raw material storage section, biogas slurry storage section, and anaerobic digestion section. We only heat the anaerobic digestion section to decrease the heating volume and reduce the heat dissipating surface, thereby saving energy. Solar energy is unstable, and the anaerobic digestion section needs to be maintained at its best temperature, thus, we control the raw material inlet at its optimum temperature. This biogas digester improves the anaerobic digestion condition and enhances gas production rate, which enables the efficient function of the digester during winter.

A Model of Solar Energy Utilisation in the Anaerobic Digestion of Cattle Manure

2003 ◽  
Vol 84 (2) ◽  
pp. 231-238 ◽  
Author(s):  
Hamed M. El-Mashad ◽  
Wilko K.P. van Loon ◽  
Grietje Zeeman
Keyword(s):  
Anaerobic Digestion ◽  
Solar Energy ◽  
Cattle Manure

scholarly journals Thermodynamic Analysis of a Rankine Cycle Powered Vapor Compression Ice Maker Using Solar Energy

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Bing Hu ◽  
Xianbiao Bu ◽  
Weibin Ma
Keyword(s):  
Solar Energy ◽  
System Performance ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Cooling Power ◽  
Condensation Temperature ◽  
Vapor Compression ◽  
Maximum Value ◽  
Ice Production

To develop the organic Rankine-vapor compression ice maker driven by solar energy, a thermodynamic model was developed and the effects of generation temperature, condensation temperature, and working fluid types on the system performance were analyzed. The results show that the cooling power per square meter collector and ice production per square meter collector per day depend largely on generation temperature and condensation temperature and they increase firstly and then decrease with increasing generation temperature. For every working fluid there is an optimal generation temperature at which organic Rankine efficiency achieves the maximum value. The cooling power per square meter collector and ice production per square meter collector per day are, respectively, 126.44 W m−2and 7.61 kg m−2 day−1at the generation temperature of 140°C for working fluid of R245fa, which demonstrates the feasibility of organic Rankine cycle powered vapor compression ice maker.

Experimental analysis of a solar absorption system with interior energy storage

2012 ◽  
Vol 23 (2) ◽  
pp. 39-49 ◽  
Author(s):  
Bilsay Pastakkaya ◽  
Nurettin Yamankaradeniz ◽  
Omer Kaynakli ◽  
Salih Coskun ◽  
Recep Yamanakaradeniz
Keyword(s):  
Energy Storage ◽  
Solar Energy ◽  
Heat Pump ◽  
Electric Heater ◽  
Cooling Power ◽  
Absorption System ◽  
Solar Absorption ◽  
Test Room ◽  
Daily Average ◽  
Absorption Cooling

This study examines experimentally the cooling application of a solar absorption system with interior energy storage that uses two different auxiliary systems. The experiments were performed at Uludag University, Bursa, Turkey on the 3rd and 4th of August 2010 that had the approximately same average outdoor temperature, 31°C. A solar hot water was delivered via a 40 m2 array of flat plate solar collectors that drove a lithium chloride (LiCl) absorption heat pump with a cooling power peak of 20 kW. A solar-powered air conditioning system was designed for heating and cooling in a test room that had a total floor space of 30 m2. Chilled water produced in the evaporator was supplied to the fan coil units, and the heat of condensation and absorption was rejected by means of a wet cooling tower. An electric heater and an air source heat pump were used as auxiliary systems for the absorption cooling application for two different cases when the solar energy was insufficient. Temperature variations were recorded for the absorption machine components, the test room, and the outdoors. The cooling energy, thermal energy, and daily average coefficient of performance (COP) of the absorption system were calculated for two days. Solar absorption cooling was considered for two different auxiliary systems and is presented in this manuscript. The results showed that the daily average COP of the absorption system was 0.283 for Case 1 and 0.282 for Case 2. For both cases, the interior energy storage of the absorption system enabled it to satisfy the cooling demand during the night while solar energy was not available.

Theoretical Study of a Building Cooling Heating Power (BCHP) System Driven by Solar Energy Based on Organic Working Fluid

2013 ◽  
Author(s):  
Jiangfeng Wang ◽  
Man Wang ◽  
Zhequan Yan ◽  
Yiping Dai
Keyword(s):  
Solar Energy ◽  
Storage System ◽  
Energy Resource ◽  
Heating Power ◽  
Working Fluid ◽  
Cooling Power ◽  
Distributed Energy Resource ◽  
Energy Demands ◽  
Building Cooling ◽  
Combined Cooling

Recently, BCHP systems as a kind of distributed energy resource present a great potential in improving energy efficiency and meeting multiple energy demands. Compared with traditional CCHP systems driven by fossil fuel, on-site renewable energy systems have more advantages in reducing carbon emissions. This paper proposes a new Building Cooling Heating Power system driven by solar energy with flat-plate solar collectors and R245fa as the working fluid. A thermal storage system is integrated into the system to store the collected solar energy and to supply heat when solar radiation is insufficient. By establishing the mathematical models of the proposed system we are able to conduct the numerical simulation of the system working in three typical operation modes around a whole year, namely the Combined Heating Power (CHP) mode in winter, the Combined Cooling Power (CCP) mode in summer, and the power production mode in spring or autumn. Results indicate that the system is able to operate continuously over a day, offering uninterrupted heating, cooling and power to building applications.

scholarly journals Performance Improvement of a Solar-Powered Recompression Supercritical Carbon Dioxide Cycle by Introducing an Ammonia-Water Cooling-Power System

2022 ◽  
Vol 9 ◽  
Author(s):  
Yicen Zhang ◽  
Yang Du ◽  
Xiaochen Lu ◽  
Pan Zhao ◽  
Yiping Dai
Keyword(s):  
Carbon Dioxide ◽  
Solar Energy ◽  
Supercritical Carbon Dioxide ◽  
Ammonia Concentration ◽  
Cooling Power ◽  
Basic Solution ◽  
Water Cooling ◽  
Power Cycle ◽  
Energy And Exergy ◽  
Main Compressor

The wide utilization of solar energy is beneficial for the emission reduction of carbon dioxide. This paper proposes a novel power cycle system driven by solar energy, which consists of a recompression supercritical carbon dioxide cycle (RSCO2) and an ammonia-water cooling-power cycle (ACPC). The power system operates in a “self-production and self-sale” mode, which means that the refrigeration capacity produced by the ACPC is utilized to cool the main compressor inlet fluid of the RSCO2. The comprehensive energy and exergy analyses of the proposed novel system are presented. The effects of the six parameters on the system thermodynamic performance are evaluated, which are direct normal irradiation, the ammonia concentration of a basic solution, the pinch point temperature difference of an evaporator, the effectiveness of a recuperator, the pressure ratio of the RSCO2 and the molten salt outlet temperature. The results show that compared with the stand-alone RSCO2, the net power and energy efficiency of the proposed system are improved by 15.94 and 10.61%, respectively. In addition, the increasing ammonia concentration of the basic solution leads to the rise of the ACPC refrigeration output, and the inlet temperature of the main compressor can be declined to 32.97°C with the ammonia concentration of the basic solution of 0.88. Moreover, when the effectiveness of the recuperator in RSCO2 rises up to 0.98, the system energy and exergy efficiencies can reach their maximum value of 30.68 and 33.10%, respectively.

Rendez vous with Saturn's rings

1984 ◽  
Vol 75 ◽  
pp. 743-759 ◽  
Author(s):  
Kerry T. Nock
Keyword(s):  
Solar Energy ◽  
Electric Propulsion ◽  
Power Source ◽  
Propulsion System ◽  
Low Thrust ◽  
Ring Plane ◽  
The Earth ◽  
Total Impulse ◽  
Saturn's Rings

ABSTRACTA mission to rendezvous with the rings of Saturn is studied with regard to science rationale and instrumentation and engineering feasibility and design. Future detailedin situexploration of the rings of Saturn will require spacecraft systems with enormous propulsive capability. NASA is currently studying the critical technologies for just such a system, called Nuclear Electric Propulsion (NEP). Electric propulsion is the only technology which can effectively provide the required total impulse for this demanding mission. Furthermore, the power source must be nuclear because the solar energy reaching Saturn is only 1% of that at the Earth. An important aspect of this mission is the ability of the low thrust propulsion system to continuously boost the spacecraft above the ring plane as it spirals in toward Saturn, thus enabling scientific measurements of ring particles from only a few kilometers.

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