Feasibility study of the application of solar heating systems in Iran

This study outlines the economic feasibility for utilization of solar heating systems for some buildings in the selected typical cities in different climatic regions of Iran. The feasibility of application of the solar heating systems has been determined by means of proper economic criteria and a life time of 25 years for capital investment. It has been found that utilization of such systems could be feasible in some of the regions for specific applications.     

太阳能供热采暖系统实例

太阳能主动式供热采暖技术在欧洲等发达国家应用已有二十多年历史,到2005年约800万m2太阳能集热器用于采暖系统,约占集热器总量的20%,每年新建太阳能采暖系统约12万个.     

Comparative study of air heating solar collectors

Three types of conventional solar air heater are designed such that their heat absorbing areas and the pressure drops across them are equal for equal air mass flow rates per unit collector area. The results of thermal performance tests conducted simultaneously on these collectors, under the same environmental conditions, are presented.     

Technical feasibility study on polycarbonate solar panels

This paper describes a technical feasibility study on the application of polycarbonate (PC) plates in a superstrate photovoltaic module design. The lamination process was performed in a conventional laminator apparatus using low temperature curing (100°C) ethylene-vinyl-acetate (EVA) as the potting material and multi-crystalline silicon solar cells. Thermo-mechanical calculations via the finite element method were performed to support the experimental results on various layer set-ups. Both experimental and numerical results revealed that PC superstrate laminates display a certain degree of warpage after the lamination process. This warpage can be attributed to stress built up in the modules due to differences in thermal expansion between solar cells and PC. This stress build-up can be diminished by application of thicker layers of PC or EVA leading to less curved laminates.     

A parametric study of open loop solar heating systems—I

The performance of open loop solar heating systems is studied using a single non-dimensional equation. For any location the long term solar fraction depends primarily on three non-dimensional groups M, K and R. M is the ratio of energy available on the collector aperture to energy demand and is hence a collector sizing parameter. K is the ratio of a reference rate of collector heat loss to a reference rate of energy available and is a collector performance parameter. R is the number of days storage available. A correlation relating the solar fraction, E, to M, K and R is given and the range of validity of this correlation is examined. For open loop systems with short term storage, the correlation can be used as a design method for a large range of demand temperatures, demand patterns, collector types and orientations. Comparisons are made between the solar fraction calculated by an hour by hour computer model and that predicted by the design method. Agreement is good. Further comparisons are made between measured and predicted performance figures for a large 20 m² domestic hot water system. It is concluded that the correlation can be used as a reliable design method and will allow simple selection of optimum system designs.     

太阳能炕采暖系统的试验研究

设计了一种新型太阳能炕采暖系统。在理论分析的基础上建立了实验平台,采用对比分析方法实测太阳能炕采暖房间和传统火炕采暖房间的室内温度和炕面温度分布情况。研究表明,太阳能炕比传统火炕炕头与炕中温差小5℃,炕中与炕尾的温差小2℃,炕面平均温度提高3.4℃,全天室内温度平均提高1.5℃。该新型采暖系统运行安全可靠,能提高室内温度,降低炕面温度的不均衡度。     

风制热技术发展及在分散式建筑供热中应用可行性探讨

针对我国农村分散式建筑采暖热源现状及存在的问题,结合我国的风力资源情况探讨利用风力制热技术为风力资源富集地区分散式建筑采暖提供热源的可行性。介绍了几种风力制热的主要方法并进行了技术优劣分析。着重阐述风磁涡流制热技术的优势,总结了风磁涡流制热的研究进展并提出其工程化应用面临的问题。最后对利用风磁涡流制热技术解决风力资源富集区分散式建筑采暖问题进行了展望。     

A parametric study of closed loop solar heating systems—II

A nondimensional equation describing the closed loop solar heating system with either parallel or series auxiliary heaters is derived. Using European weather data the monthly solar fraction is calculated for variations in the major non-dimensional groups. A correlation is given relating the solar fraction to three non-dimensional parameters M, Kc and Rc. M is the ratio of energy available on the collector aperture to energy demand. To calculate the energy available it is necessary to know the monthly utilizability. Kc is the ratio of the store temperature required for a 100 per cent solar contribution to the average monthly collector peak stagnation temperature. Both these temperatures are referenced to the demand temperature. Rc is the effective “turn over time” of the store, i.e. the number of days to empty the energy contents of the store. The magnitudes of Kc and Rc depend on the load heat exchanger size. Comparisons between the solar fraction predicted with a dimensional hour by hour computer model and that by the correlation are made for two system types. The agreement is good and it is concluded that the correlation can be used as a reliable method to optimise closed loop solar heating systems.     

A feasibility study into joining of engineering thermoplastics utilising concentrated beam solar radiation

Most manufacturing technologies and facilities today are being developed for efficient and environment-friendly production. However, regardless of what type of material processing technology we use, we need energy. Solar energy, although often called alternative or even new energy source, is probably the oldest energy source available on earth. In this paper, the attempts made by the authors to explore the feasibility of utilising concentrated solar beam radiation for joining engineering thermoplastics such as acrylonitrile/butadiene/styrene (ABS), polycarbonate (PC) and polymethylmethacrylate (PMMA) are presented. In addition, to study the joining of the materials, necessary experimentation with applying primer was performed. Tensile tests were conducted to determine the bond strength achieved at the specimen joint interface. Microscopic examinations of the fractured joints were performed in order to analyse the overall bond quality. Finally, the results in terms of bond strength achieved at the joint interface and energy consumed in the process were compared with those obtained with similar thermoplastic joining technique utilising microwave energy. In conclusion, some advantages and limitations were outlined and necessary improvements of the joining technique were recommended.     

太阳能低温热水地板辐射供暖系统的研究

低温地板辐射供暖具有舒适、节能、清洁等许多优点，这种供暖方式已在我国北方得到广泛的应用。研究、开发廉价和清洁的辐射供暖的低温热源－太阳能，对于大面积推广低温辐射供暖系统具有十分重要的意义。     

太阳能供热采暖技术讲座(7) 太阳能供热采暖系统的施工

<正>一一般要求太阳能供热采暖系统的安装施工与太阳能热水系统类同,主要包括进场准备、基础施工、钢结构施工、集热器安装及管路施工、水箱安装、电控施工、调试运行等。在新建建筑上安装太阳能系统时,应尽可能与建筑同步施工,保证集热器和水箱等部件的安装基     

热水采暖系统应用冷凝式锅炉的可行性研究

天然气供热锅炉排烟温度较高 ,可以通过加装冷凝式换热器改造为冷凝式锅炉回收烟气潜热 ,降低排烟温度 ,提高锅炉效率。排烟余热用来加热供热系统回水时 ,由于 95 70℃供热系统回水设计温度较高而无法利用烟气潜热 ,但实际上由于供热系统调节 ,回水温度大部分时间内低于烟气露点。本文研究发现加热 95 70℃供热系统回水是可以利用烟气潜热的。     

Environmental,technical and financial feasibility study of solar power plants by RETScreen,according to the targeting of energy subsidies in Iran

In this study, based on new electricity tariffs, three scenarios have been developed with The RETScreen International Photovoltaic Project Model, according to the targeting of energy subsidies in Iran. We have also dedicated one of our scenarios to the reduction of greenhouse gasses.In the first case the electricity price was set to 3.75 Cents/kWh (450 Rial/kWh) and no credit was assigned to the reduction of greenhouse gasses (GHG), therefore equity payback (Return positive cash flow) has been 12.1 year. In the second case the electricity price was set to 17.5 Cents/kWh, therefore equity payback (return positive cash flow) was 8 year. Finally in the last scenario by considering a credit to the reduction of greenhouse gasses and electricity price being 175 Cents/kWh and applying solar panels with high efficiency and suitable batteries (DOD = 60%), equity payback (return positive cash flow) reached within 6 years.     

A design procedure for solar heating systems

This paper is concerned with the design of solar space and water heating systems for residences. A simulation model capable of estimating the long-term thermal performance of solar heating systems is described. The amount of meteorological data required by the simulation in order to estimate long-term performance is investigated. The information gained from many simulations is used to develop a general design procedure for solar heating systems. The result is a simple graphical method requiring monthly average meteorological data which architects and heating engineers can use to design economical solar heating systems. A method of estimating the monthly average radiation on tilted surfaces is given in the Appendix.     

A feasibility study of integrally colored Al–Si as a solar selective absorber

The solar selective properties of integrally colored Al–Si alloy (11.6 wt% Si) have been investigated. Optical measurements showed a continuous decrease of reflectance, i.e. an increase of absorptance, with increasing film thickness. A maximum solar absorption of 0.85 was achieved for Si–Al₂O₃ coatings thicker than 13 μm but such thick aluminum oxide coatings have very high thermal emittance.The reflectance of the Si–Al₂O₃ coated aluminum could be understood from a four flux radiative transfer theory. Using this theory the optical performance of the coating as a solar absorber was modeled for different size and volume fractions of silicon particles and coating thicknesses. A solar absorptance of just 0.90 can be achieved from a 10 μm thick coating of about 0.3 volume fraction of silicon. For thinner coatings (1 μm) the solar absorptance was only 0.70 for the same volume fraction.     

太阳能采暖系统的基本类型

在第一讲介绍太阳能供热采暖系统分类的基础上,本讲着重讨论其中最基本的液体集热器太阳能采暖系统、空气集热器太阳能采暖系统和低温热水地板辐射太阳能采暖系统.     

The feasibility of manufacturing wind turbines in Iran

It is known that the supplies of fossil fuels are limited and their utilization as energy sources causes environmental degradation due to incomplete combustion when used as energy source, in addition to this as the world population increases the demand for energy sources increases, therefore the issue of a gradual replacement of fossil fuels with renewable energy sources is of major consideration for most countries: Iran Bing located in Asian Middle East enjoys a great potential for producing some 6500 MW of electricity with wind energy. The feasibility of manufacturing wind turbines is investigated in this article.     

热管太阳能集热器系统的研究

建筑物大面积集中供热已成为节能降耗的新,也是太阳能热利用发展的趋势。文章介绍了在原有铜铝复合板的基础上,试制的一种结合多层建筑的集中供热热管式太阳能供热系统,克服了原有的平板式和真空管式集热系统易炸管,易冻裂及结垢,单管损坏后整个系统失效等问题。     

Economic feasibility of solar pumping

Two major questions concerning the economic feasibility of solar pumping are addressed. The first of these is concerned with finding a least-cost solar system by considering the alternative use of either thermal or water storage. The second involves the determination of areas where solar energy would be economically competitive with electricity or fuel as a power source for pumping installations.A linear programming solution is developed to find the optimal combination of thermal and water storage for a solar installation. The formulation is then extended to determine a least-cost system when hybrid systems are considered. A hybrid system may incorporate a combination of solar, electric and fuel power inputs. The concept of a breakeven “critical” distance from existing infastructure for solar installations is developed, and an example problem is provided to illustrate typical values of this distance and to show its sensitivity to the base energy costs and rate of inflation for those costs. It appears that electrical pumping is probably the most economical alternative provided that electric infrastructure is located nearby. Fuel power will also be more economical than solar if there is a source of fuel near the proposed pumping site. However, solar systems may be economically competitive when considered for installation at realistic distances from existing infrastructure.