scholarly journals Solar Air Heaters with Thermal Heat Storages

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Abhishek Saxena ◽  
Varun Goel

Solar energy can be converted into different forms of energy, either to thermal energy or to electrical energy. Solar energy is converted directly into electrical power by photovoltaic modules, while solar collector converts solar energy into thermal energy. Solar collector works by absorbing the direct solar radiation and converting it into thermal energy, which can be stored in the form of sensible heat or latent heat or a combination of sensible and latent heats. A theoretical study has been carried out to rate the various thermal energy storage commonly used in solar air heaters. During the investigations rock bed storages have been found to be low type thermal heat storage, while phase change materials have been found to be high heat thermal storages. Besides this, a few other heat storing materials have been studied and discussed for lower to higher ratings in terms of thermal performance purposely for solar heaters.

Author(s):  
RAMESH C ◽  
SEKAR M

The depletion of conventional energy source, the need for unconventional energy is focused on solar energy as it is avail plentiful. Converting the solar energy in to thermal energy is the effective way of utilization of solar energy rather the conversion of electrical energy. This paper compared the behavior of solar collector at 30º and 45º angles with black chrome coated absorber plate without and with glass reflectors. In the view of performance enhancement of the collector, the reflector was adjusted to maximize the incident ray for every hour. It is found that the collector fixed at 30º with ground heats the water better and again the performance can be increased by the reflector.


2018 ◽  
Vol 67 ◽  
pp. 04011
Author(s):  
Sunaryo Sunaryo ◽  
Adri Wirawan Ramadhani

Indonesia has more than 17,000 islands and has plenty of beautiful beaches and underwater spots which have great potential for maritime tourism. Tourism was ranked 3rd on Indonesia's foreign income and plays an important role for the country’s ecomony. Despite having potential advantages, the government has not yet maximized its efforts to develop the attractiveness of its maritime tourism. Beside the beautiful spots Indonesia is also blessed with all year long sun shine, which could be tapped as renewable and green energy as substitution to fossil fuel. Refer to these great advantages of natural resources the research was aimed to support the government’s program in developing its maritime tourism and to promote the use of green and renewable energy by designing a solar-powered tourism recreational boat which has 12 meters of length. The paper is focused on the design of solar energy and its electrical system, which includes conversion of solar energy to electrical energy and store it in the battery, the required electrical power is also predicted based on the appliances and equipment installed in the boat, the optimum attachment of solar panels on the boat structure is also calculated. All the methods and information we use are obtained from literature study, discussion with experts, and surveys to Jagur as solar-powered electric boat from Universitas Indonesia.


2014 ◽  
Vol 634 ◽  
pp. 72-82
Author(s):  
Rosa Ana Conte ◽  
Daltro Garcia Pinatti ◽  
Luiz Fernando M. Marton ◽  
Sebastião Ribeiro ◽  
Thaís Witt Acosta ◽  
...  

Production of active rice husk silica (ARHS) in bubbling fluidized bed boiler of a thermoelectric unit (TEU) and its addition to high performance concrete (HPC) with a compression resistance of 90 MPa was developed in the last 10 years. A first factory in Brazil was established at Alegrete town, RS, and other factories are under planning. Data of ARHS production, specification and HPC trace are presented. Design of parabolic solar collector coverage (PSCC) for air heating for biomass drying in a special silo of the TEU is presented as well. Cost of HPC/ARHS is 10 times less than steel (USD 200/ton vs. USD 2000/ton, specific mass 2.5 vs. 7.6 g/cm3, respectively). Those characteristics allow simultaneous solution of four ecological problems: large span coverage, rain water collection, daily solar energy collection and storage, and drying of biomass. The integration of those characteristics results in decrease of biomass consumption maintaining the same UTE efficiency. Tracking parabolic solar collector can be avoided between Cancer and Capricorn Tropics, and it is sufficient its eastern-western orientation with inclination to the Equator by the latitude angle. Coverage of the area occupied by TEU is sufficient to dry its biomass consumption. Preheating of boiler water with solar energy is possible decreasing biomass consumption in sunny days; biomass is partially consummed at night and cloudy days. Coupling the above technologies with high pressure steam TEU and fast-growing short-rotation forest gives to the biomass electrical energy generation a competitive economical position with hydraulic, coal, natural gas, and aeolic energy generation.


Author(s):  
Mustafa Aktaş ◽  
Meltem Koşan ◽  
Erhan Arslan ◽  
Azim Doğuş Tuncer

The integrated usage of solar energy systems, heat pump applications, and thermal energy storage units is an effective way for heating systems due to their sustainability and stability in operations. In this study, a novel direct solar-assisted heat pump with thermal energy system has been designed which uses the solar collector as the evaporator of the heat pump. Besides, two-dimensional transient numeric analyses have been conducted for the thermal energy storage unit using the ANSYS Fluent 16.2 commercial software package. With this direct system, the heat required for heating systems is supplied from the condenser with the heat received from the solar collector of the working fluid. For an effective and high performance system, the solar collector is designed as a double-pass which provided superheating of the working fluid. It is aimed to store the surplus energy from the solar energy in the thermal energy storage unit and to operate the system continuously and efficiently in both sunny and overcast weather conditions. Furthermore, the system has been analyzed theoretically and the results show that coefficient of performance may improve. As a result, this newly designed system can be successfully applied for thermal applications.


2019 ◽  
Vol 889 ◽  
pp. 526-532
Author(s):  
Thai Viet Dang ◽  
Si Thong Dinh ◽  
Xuan Toi Bui

Currently, the world has a lot of research and practical application of intelligent building systems integrated with intelligent power systems. Because Vietnam is a country with potential for solar energy, the integrator of solar energy is being strongly developed. However, the research result of the optimization of electrical energy used by the intelligent type solar integration is rare. This paper presents the design and structure of the module of intelligent control and monitoring via wireless network integrated with the automatic solar concentration system. The system allows easy connection and operation of all electrical power sources including the dispersal solar power to ensure the efficient and lower power consumption. In addition, the solar cell system is applied the Maximum Power Point Tracking technique (MPPT), which helps to stabilize and improve the power generation efficiency of the PV panels. The test results on the module showed absorption performance of automatic solar-cell flat plate systems is raised by 20-30% and power consumption in small households reduced approximately 30%.


Author(s):  
Zongli Xie ◽  
Derrick Ng ◽  
Manh Hoang ◽  
Jianhua Zhang ◽  
Stephen Gray

Desalination by pervaporation is a membrane process that is yet to be realized for commercial application. To investigate the feasibility and viability of scaling up, a process engineering model was developed to evaluate the energy requirement based on the experimental study of a hybrid polyvinyl alcohol/maleic acid/tetraethyl orthosilicate (PVA/MA/TEOS) Pervaporation Membrane. The energy consumption includes the external heating and cooling required for the feed and permeate streams, as well as the electrical power associated with pumps for re-circulating feed and maintaining vacuum. The thermal energy requirement is significant (e.g., up to 2609 MJ/m3 of thermal energy) and is required to maintain the feed stream at 65 °C in recirculation mode. The electrical energy requirement is very small (<0.2 kWh/m3 of required at 65 °C feed temperature at steady state) with the vacuum pump contributing to the majority of the electrical energy. The energy required for the pervaporation process was also compared to other desalination processes such as Reverse Osmosis (RO), Multi-stage Flash (MSF), and Multiple Effect Distillation (MED). The electrical energy requirement for pervaporation is the lowest among these desalination technologies. However, the thermal energy needed for pervaporation is significant. Pervaporation may be attractive when the process is integrated with waste heat and heat recovery option and used in niche applications such as RO brine concentration or salt recovery.


2013 ◽  
Vol 24 (4) ◽  
pp. 51-62
Author(s):  
Shadreck M. Situmbeko ◽  
Freddie L. Inambao

Solar thermal energy (STE) technology refers to the conversion of solar energy to readily usable energy forms. The most important component of a STE technology is the collectors; these absorb the shorter wavelength solar energy (400-700nm) and convert it into usable, longer wavelength (about 10 times as long) heat energy. Depending on the quality (temperature and intensity) of the resulting thermal energy, further conversions to other energy forms such as electrical power may follow. Currently some high temperature STE technologies for electricity production have attained technical maturity; technologies such as parabolic dish (commercially available), parabolic trough and power tower are only hindered by unfavourable market factors including high maintenance and operating costs. Low temperature STEs have so far been restricted to water and space heating; however, owing to their lower running costs and almost maintenance free operation, although operating at lower efficiencies, may hold a key to future wider usage of solar energy. Low temperature STE conversion technology typically uses flat plate and low concentrating collectors such as parabolic troughs to harness solar energy for conversion to mechanical and/or electrical energy. These collector systems are relatively cheaper, simpler in construction and easier to operate due to the absence of complex solar tracking equipment. Low temperature STEs operate within temperatures ranges below 300oC. This research work is geared towards developing feasible low temperature STE conversion technology for electrical power generation. Preliminary small-scale concept plants have been designed at 500Wp and 10KWp. Mathematical models of the plant systems have been developed and simulated on the EES (Engineering Equation Solver) platform. Fourteen candidate working fluids and three cycle configurations have been analysed with the models. The analyses included a logic model selector through which an optimal conversion cycle configuration and working fluid mix was established. This was followed by detailed plant component modelling; the detailed component model for the solar field was completed and was based on 2-dimensional segmented thermal network, heat transfer and thermo fluid dynamics analyses. Input data such as solar insolation, ambient temperature and wind speed were obtained from the national meteorology databases. Detailed models of the other cycle components are to follow in next stage of the research. This paper presents findings of the system and solar field component.


2016 ◽  
Author(s):  
M. T. Nitsas ◽  
I. P. Koronaki ◽  
A. S. Kontos

The scope of this work is the analysis of the electrical and thermal performance of an asymmetric hybrid solar collector PVT and the prospect of the installation of a system consisting of these collectors in the Mediterranean region. For the purpose of this work, the Solarus V11 PVT collector (readily available in our laboratory) was chosen and numerically modeled. The main asset of this collector is its asymmetric reflector that consists of a circular and a parabolic part leading to a maximum thermal energy production even in winter as the solar radiation is concentrated in the edge of the reflector rather than in the center of it. Using a software developed in Matlab, the calculated data are presented for both thermal and electrical energy and they are compared with the hot water and electrical energy requirements (per month) around the Mediterranean territory. Furthermore, a parametric study is conducted in order to investigate the effect of the mass flow rate and the PVT array configuration on the thermal and electrical production, as well as the efficiency of the solar cells of the system. Moreover, in order to increase the PV cell efficiency, nanofluids, i.e. mixtures of nanometer size particles well-dispersed in a base fluid, are proposed as heat transfer fluids and the analysis for the performance evaluation is conducted for different nanoparticle loadings.


2012 ◽  
Vol 608-609 ◽  
pp. 97-113 ◽  
Author(s):  
José Rui Camargo ◽  
Jamir Machado da Silva ◽  
Ederaldo Godoy Junior ◽  
Renan Eduardo da Silva ◽  
Luiz Eduardo Nicolini do Patrocínio Nunes ◽  
...  

All photovoltaic panel heats up when exposed to sunlight and this heating reduces the electrical power output of the same. This work presents the use of this unwanted waste heat, converting it into thermal energy directly by means of the Seebeck effect, which is the direct conversion of thermal energy into electrical energy by means of an arrangement of semiconductor materials that when exposed to temperature gradients generate electric current. In this work emphasis was placed on the influence of temperature on generation processes involved. Thus, the theoretical evaluation, it presents the mathematical models of thermoelectric and photovoltaic systems by raising the curves of voltage, current and electric power generated, and analyses the influence of temperature in each model. To obtain the simulation curves it uses MATLAB ® 5.3, taking into account the parameters of thermoelectric modules and real photovoltaic cells. In practical evaluation, a prototype was assembled containing thermoelectric module attached to the bottom of a photovoltaic panel in order to use the heat energy absorbed by the panel. The data were stored and analyzed, where we observed the influence of temperature in both systems, validating the mathematical modeling. It is the applicability of the mathematical model given the results obtained with the prototype system.


2012 ◽  
Vol 4 (1) ◽  
pp. 14-19
Author(s):  
Valdi Rizki Yandri

Energy has important meaning in social and economics achievement to continously development and support to national economics activities. Energy consumption in Indonesia increases rapidly parallel with economics engagement and people growth. To supply energy requirement, renewable energy source should be developed. Renewable energy potency like solar energy hasn’t been used for big scale although Indonesia has big energy potency. Indonesia be included on tropical area which is exposed sun radiance almost year. It means solar energy has good prospects to be developed in Indonesia. Solar energy is one kind of energy which is gotten by converting sun calor energy to another type of energy. Solar energy can be used in form solar cell for electrical power plant. The utilization of solar cell can help people who lives on isolated area which is far from electrical network to use electrical energy.


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