scholarly journals Performance of solar hot-water installations from roof-constructed solar collectors integrated with a central heating supply for tobacco curing

2020 ◽  
Vol 24 (3 Part A) ◽  
pp. 1845-1852
Author(s):  
Jianan Wang ◽  
Fengjie Wei ◽  
Weidong Duan ◽  
Yonghui Zhang ◽  
Yikuan Fan ◽  
...  

In view of the abundant solar energy available during the tobacco curing season, a solar hot-water installation to provide auxiliary heating for bulk tobacco-curing operations was developed, based on the original concept of a boiler-driven central heating supply that transported hot water over short distances by pipeline, using solar collectors connected in parallel and installed on the unoccupied flat roofs of 20 curing barns. The results showed that daily solar conversion efficiency ranged from 65% to 67%. During the tobacco curing period from 10:00 hours to 14:00 hours each day, in sunny or partly cloudy weather, heating water temperatures exceeding 75?C were automatically derived for use in the bulk curing barns needed. Use of solar energy as a substitute for coal fuel in tobacco curing, in conjunction with precise automatic control, enabled solar energy to account for 18.4% of the total curing energy consumption in this study. Through comparative analysis, the use of solar hot-water installations can help the local tobacco industry to reduce absolute carbon emissions by more than 10% at the experimental location in the pay-back period.

Author(s):  
Andy Walker ◽  
Fariborz Mahjouri ◽  
Robert Stiteler

This paper describes design, simulation, construction and measured initial performance of a solar water heating system (360 Evacuated Heat-Pipe Collector tubes, 54 m2 gross area, 36 m2 net absorber area) installed at the top of the hot water recirculation loop in the Social Security Mid-Atlantic Center in Philadelphia. Water returning to the hot water storage tank is heated by the solar array when solar energy is available. This new approach, as opposed to the more conventional approach of preheating incoming water, is made possible by the thermal diode effect of heat pipes and low heat loss from evacuated tube solar collectors. The simplicity of this approach and its low installation costs makes the deployment of solar energy in existing commercial buildings more attractive, especially where the roof is far removed from the water heating system, which is often in the basement. Initial observed performance of the system is reported. Hourly simulation estimates annual energy delivery of 111 GJ/year of solar heat and that the annual efficiency (based on the 54 m2 gross area) of the solar collectors is 41%, and that of the entire system including parasitic pump power, heat loss due to freeze protection, and heat loss from connecting piping is 34%. Annual average collector efficiency based on a net aperture area of 36 m2 is 61.5% according to the hourly simulation.


Author(s):  
Ion V. Ion ◽  
Gheorghe Ciocea ◽  
Florin Popescu

Abstract In this work, the reduction of greenhouse gas emission, and the energy saving by integrating solar collectors and photovoltaic panels in a Stirling engine based microcombined cooling, heating and power (mCCHP) system are studied. The mCCHP system consists of a natural gas Stirling CHP and an adsorber chiller. When the thermal outputs of the Stirling CHP and solar collectors are not sufficient to cover the heat demand for domestic hot water (DHW), heating/cooling, an auxiliary heating boiler starts to operate. The energy saving by using solar energy varies from 13.35% in December to 59.62% in April, in the case of solar collectors usage and from 7.47% in December to 28.27% in July, in the case of photovoltaic panels usage. By using solar energy the annual GHG emission decreases by 31.98% and the fuel cost reduction varies from 12.73% in December to 49.78% in June.


Author(s):  
Enrico Zambolin ◽  
Davide Del Col ◽  
Andrea Padovan

New comparative tests on different types of solar collectors are presented in this paper. Tests have been performed at the solar energy conversion laboratory of the University of Padova. Two standard glazed flat plate collectors and one evacuated tube collector are installed in parallel; the evacuated collector is a direct flow through type with external CPC (compound parabolic concentrator) reflectors. The present test rig allows to make measurements on the flat plate, on the evacuated collector or on both simultaneously, by simply acting on the valves to modify the circuit. In this paper measurements of the performance of the evacuated tube collector and flat plate collectors working at the same conditions are reported. Efficiency in stationary conditions is measured following the standard EN 12975-2 [1] and it is compared with the input/output curves measured for an entire day. The main purpose of the present work is to characterize and to compare the daily energy performance of the two types of collectors. An effective mean for describing and analyzing the daily performance is the so called input/output diagram, in which the collected solar energy is plotted against the daily incident solar radiation. Test runs have been performed in several conditions to reproduce different conventional uses (hot water, space heating, solar cooling).


Solar Energy ◽  
2004 ◽  
Author(s):  
Oleg P. Kovalev ◽  
Alexandr V. Volkov

During long-term time, the laboratory of non-traditional energetic is been busy with development and introduction of solar water heating systems for hot water supply. The systems with solar collectors of 40 m2 area have been developed and introducted. For estimation of their efficiency we should know flux density of solar radiation, proceeding to surface at the given place. However in Primorye Region at actinometrical watching only four meteostations in the Southern part are carrying out straight measurements of solar radiation flux, and the others record data which concern only solar radiation regime (the amount of solar radiation hours, relation of watching duration of solar radiation to possible duration, the amount of days without sun, etc.). We suggested the expression, which according to know data of solar radiation and cloudiness, recorded practically on all meteorological stations gives possibility to calculate for Primorye Region month sums of total radiation proceeding to horizontal surface. The comparison of estimated values with measured ones gives the error to 3...9% with regard to average many years values, and are in the range of variability of measured values for separate years. In Primorye Region more than 250 m2 of solar collectors were installed; and among them 150 m2 were developed with the laboratory, to position on 2003.11.01.   NOTE: This paper was presented at the 2004 International Solar Energy Conference and was inadvertently omitted from the 2004 ASME proceedings. The page range refers to the 2005 International Solar Energy Conference Print Proceedings, where it was subsequently published.


2018 ◽  
Vol 174 ◽  
pp. 01038 ◽  
Author(s):  
Łukasz Kolendo ◽  
Dorota Anna Krawczyk

The provisions in the European and Polish law oblige to increase the use of energy obtained from renewable energy sources. In order to meet these demands, it is necessary to take into account the singlefamily housing sector that has a significant energy potential. Among the unconventional heat sources that have gained the highest popularity, it is worthy to note installations using solar energy for instance to prepare DHW (domestic hot water) or be used in buildings’ heating. It is also worth mentioning that this type of technical solutions can be successfully used as well in new as modernized old residential buildings. Our paper discusses the problems associated with planning of solar installations with flat and vacuum solar collectors mounted on the roofs of the single-family buildings. During the analysis we used GIS&T technology, multi-criteria decision support as well as detailed spatial data obtained by modern remote sensing techniques including airborne laser scanning. The proposed methodology and tools were used on the example of the selected part of a single-family housing estate located in Bialystok. The research focused on issues of the multi-criteria assessment of the assembly of use of roofs for solar collectors, including data on a solar potential, exposure, slope, surface and roofs’ shape. Additionally, we took into account roof zones on being in a shadow caused by roof elements, roof infrastructure and high vegetation. Based on the simulation results we analyzed possibility of plate and tube solar collectors’ application that would provide warm water for 1-4 habitants of houses. The results of our research showed high utility of the proposed methods in the field of spatial and economic assessment of the use of solar collectors in the single-family housing sector.


2020 ◽  
Vol 2 (2) ◽  
pp. 69-74
Author(s):  
S. HORIASHCHENKO ◽  
◽  
Yu. KRAVCHIK ◽  
O. PIDGORNYI ◽  
◽  
...  

Solar energy is widely used in cases where the inaccessibility of other energy sources in combination with a sufficient amount of solar radiation justifies it economically. With the help of a system of solar collectors, you can significantly reduce energy costs for hot water supply and heating. In addition, the use of this system helps reduce CO2 emissions. The potential of solar energy in Ukraine is quite high. According to the climatic conditions of our region, solar activity is slightly lower than in the southern regions, so the use of flat solar collectors, which use both direct and scattered solar radiation, is effective for our region. The use of heat collectors in the home for water supply and heating of small areas is economically feasible, as it does not require significant costs. Heat supply plants using non-traditional energy sources are promising in terms of fuel savings and reduction of harmful effects on the environment. To increase the service life, economical use of heat and fuel, efficient operation of the installation requires the use of automation. The article considers the development of a mathematical model of a heat supply installation based on a solar collector. For automated control of the heat supply installation, it is necessary to know the properties of this installation as a whole and its individual elements. For this purpose, models of individual elements of the heat supply installation in a linear approximation are considered. The solar collector is conditionally divided into two parts. The model of the ground heat exchanger is developed. Also e battery models and consumer premises. The given matrices of elements of installation of heat supply are united in the uniform system of matrices. The obtained results allow estimating in advance efficiency of their use and economic attractiveness.


2018 ◽  
Vol 1 (2) ◽  
pp. 40-51 ◽  
Author(s):  
Muhammad Burhan ◽  
Muhammad Wakil Shahzad ◽  
Kim Choon Ng

Standalone power systems have vital importance as energy source for remote area. On the other hand, a significant portion of such power production is used for cooling purposes. In this scenario, renewable energy sources provide sustainable solution, especially solar energy due to its global availability. Concentrated photovoltaic (CPV) system provides highest efficiency photovoltaic technology, which can operate at x1000 concentration ratio. However, such high concentration ratio requires heat dissipation from the cell area to maintain optimum temperature. This paper discusses the size optimization algorithm of sustainable cooling system using CPVT. Based upon the CPV which is operating at x1000 concentration with back plate liquid cooling, the CPVT system size is optimized to drive a hybrid mechanical vapor compression (MVC) chiller and adsorption chiller, by utilizing both electricity and heat obtained from the solar system. The electrolysis based hydrogen is used as primary energy storage system along with the hot water storage tanks. The micro genetic algorithm (micro-GA) based optimization algorithm is developed to find the optimum size of each component of CPVT-Cooling system with uninterrupted power supply and minimum cost, according to the developed operational strategy. The hybrid system is operated with solar energy system efficiency of 71%.


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