碟式斯特林太阳能发电系统研究

设计了斯特林太阳能发电系统,构建了斯特林系统模型,并以此模型进行了发电系统仿真研究,结果表明,太阳能发电系统的发电效率变化处于持续平稳状态,而输出功率则与太阳直射强度变化状态相类似;系统热端温度基于太阳直射强度变大且超出设定值状态时,开启充气阀,则工质循环压力上升,而发动机转速不变时,发动机热端温度则呈现下降趋势;短时...     

碟式斯特林太阳能热发电系统接收器聚热技术

接收器在碟式斯特林太阳能热发电系统的能量转换效率中起着重要的作用。介绍了接收器的一般分类和结构特点,并利用12m聚光碟进行有关接收器在不同尺寸下的内部聚热量和温度分布等相关研究.试验结果表明,在相同条件下,接收器内聚热量的大小取决于聚光碟的聚焦能力和接收器的结构尺寸,接收器的深度和聚热量成反比,深度越小,聚热量越大;接收器的深度和加热管的温差成反比,深度越大,温差越小。试验所得数据和聚热规律,可为后续的接收器设计和制造提供有效的改进依据。     

碟式斯特林太阳能发电系统最新进展

太阳能热发电技术中最具发展潜力的是碟式太阳能高温发电技术,尤其是近几年碟式斯特林太阳能发电技术更是令世界瞩目,它具有光电转换效率高、耗水量低、发电方式灵活及可逐步规模化等特点。目前,国内外碟式斯特林太阳能发电系统的研制方兴未艾,国外太阳能斯特林发电机制作及测试技术已趋于成熟,正处于中试和大规模推广阶段。国外主要的碟式斯特林发电系统包括SES公司的SunCatcher单元、Cleanergy公司的Eurodish单元、Infinia公司的PowerDish单元等。国内碟式斯特林太阳能热发电技术研究取得了一些成绩,但总体来说,目前还未获得实质性的进展,相关研究尚处于初级阶段。碟式斯特林太阳能发电系统的核心部件是太阳能斯特林发电机,其某些关键部件的研发难度较大,如高温太阳能吸收器、高效回热器、工质密封、功率和转速控制等。要攻克这些关键技术,需要国内外相关部门的大力支持。我国科研工作者应通过各种形式与国外斯特林发电机制造商及科研机构进行技术合作,逐渐掌握此项技术;或者借鉴国外的研制经验自主研发,然后通过示范推广,建设大型碟式斯特林太阳能发电厂。     

碟式/斯特林太阳能热发电系统设计Ⅰ--集热器设计计算数学模型

在碟式斯特林太阳能热发电系统没有商业运行以前，无法得到国外已有系统设计方法的情况下，提出了以能量守恒方程和集热器光学特性为基础的设计计算数学模型，并使用估算和核算相结合的方法进行了设计计算。计算结果与现有系统参数吻合良好。     

浅析碟式太阳能发电技术

随着化石能源的大量开采,油价煤价不断上涨,充分利用太阳能显然具有可持续发展和节能减排的双重伟大意义。太阳能技术的大力推广在很大程度上缓解了能源问题。综合近年来国内外碟式太阳能发电技术,基于斯特林发动机,叙述了碟式／Stirling系统的构成、发电原理、发展现状,指出了目前存在的问题,提出了改善措施。     

碟式斯特林太阳能热发电的技术发展

碟式斯特林太阳能热发电是目前发电效率最高的太阳能热发电的技术.介绍了碟式斯特林太阳能热发电系统原理,论述了国际上目前以热气机为核心技术的碟式太阳能热发电系统发展状况.指出我国的燃气热气机发电技术已经取得了突破性的发展,25 kW级碟式斯特林太阳能热发电系统的研发已具备了技术基础.     

斯特林发动机在空间太阳能发电中的应用

提出了空间太阳能发电系统中采用自由活塞式期特林发动机发电装置的概念设计模型,确立了整个概念设计的框架,并对自由活塞式斯特林发动机作了初步设计,同时对有关问题进行了讨论,提示了今后的发展方向。     

小型斯特林发电测试系统的设计

阐述了小型斯特林发电测试系统的组成部分,并对发动机的热腔温度、冷腔温度、转速、输出扭矩、发电机输出电压、电流等重要参数进行测量,并对结果进行了分析和讨论。     

斯特林发动机的绝热分析

用绝热分析法建立并模拟了斯特林循环的理想绝热模型,仿真结果显示,增大循环压力能提高斯特林发动机的做功能力,这为以后建立非理想绝热模型和节点分析模型奠定了基础.     

Exergetic analysis and performance evaluation of parabolic dish Stirling engine solar power plant

In this communication, a 50 MW_e design capacity parabolic dish Stirling engine solar power plant (PDSSPP) has been modeled for analysis, where 2000 units of parabolic dish Stirling engine each having capacity of 25 kW_e were considered to get desired capacity. An attempt has been made to carry out the energetic and exergetic analysis of different components of a solar power plant system using parabolic dish collector/receiver and Stirling engine. The energetic and exergetic losses as well as efficiencies for typical PDSSPP under the typical operating conditions have been evaluated. Variations of the efficiency of Stirling engine solar power plant at the part‐load condition are considered for year‐round performance evaluation. The developed model is examined at location Jodhpur (26.29°N, 73.03°E) in India. It is found that year‐round energetic efficiency varies from 15.57% to 27.09%, and exergetic efficiency varies from 16.83% to 29.18%. The unit cost of electric energy generation (kW_eh) is about 8.76 Indian rupees (INR), with 30 years life span of the plant and 10% interest rate on investment. Copyright © 2012 John Wiley & Sons, Ltd.     

Development of an experimental test rig for cogeneration based on a Stirling engine and a biofuel burner

A system consisting of a last-generation Stirling engine (SE) and a fuel burner for distributed power generation has been developed and experimentally investigated. The heat generated by the combustion of two liquid fuels, a standard Diesel fuel and a rapeseed oil, is used as a heat source for the SE, that converts part of the thermal energy into mechanical and then electric energy. The hot head of the SE is kept in direct contact with the flame generated by the burner. The burner operating parameters, designed for Diesel fuel, were changed to make it possible to burn vegetable oils, not suitable for internal combustion engines. The possibility of adopting different configurations of the combustion chamber was taken into account to increase the system efficiency. The preliminary configurations adopted allowed to operate this integrated system, obtaining an electric power up to 4.4 kW_el with a net efficiency of 11.6%.     

Thermal model of a dish/Stirling systems

This paper presents a global thermal model of the energy conversion of the 10 kW_el Eurodish dish/Stirling unit erected at the CNRS-PROMES laboratory in Odeillo. Using optical measurements made by DLR, the losses by parabola reflectivity and spillage are calculated. A nodal method is used to calculate the heat losses in the cavity by conduction, convection, reflection and thermal radiation. A thermodynamic analysis of a SOLO Stirling 161 engine is made. The Stirling engine is divided in 32 control-volumes and equations of ideal gas, mass and energy conservation are written for each control-volume. The differential equation system is resolved by an iterative method developed using Matlab^™ programming environment. Temperature, mass, density of working gas, heat transfers and the mechanical power are calculated for one Stirling engine cycle of 40 ms and for a constant direct normal irradiation (DNI). The model gives consistent results correctly fitting with experimental measurements.     

Energy system feasibility study of an Otto cycle/Stirling cycle hybrid automotive engine

The aim of this study was to investigate the feasibility of utilising a Stirling cycle engine as an exhaust gas waste heat recovery device for an Otto cycle internal combustion engine (ICE) in the context of an automotive power plant. The hybrid arrangement would produce increased brake power output for a given fuel consumption rate when compared to an ICE alone. The study was dealt with from an energy system perspective with design practicalities such as power train integration, location of auxiliaries, manufacture costs and other general plant design considerations neglected. The study necessitated work in two distinct areas: experimental assessment of the performance characteristics of an existing automotive Otto cycle ICE and mathematical modelling of the Stirling cycle engine based on the output parameters of the ICE. It was subsequently found to be feasible in principle to generate approximately further 30% useful power in addition to that created by the ICE by using a Stirling cycle engine to capture waste heat expelled from the ICE exhaust gases over the complete range of engine operating speeds.     

Optimization of the irreversible Stirling heat engine

The effects of inefficiencies in the compression, expansion and regeneration processes on engine performance have been evaluated theoretically for a Stirling heat engine operating in a closed regenerative thermodynamic cycle. The irreversible cycle has been optimized by using the maximum power density technique. Maximized power and maximized power density are obtained for different n_ex, τ, α_c, α_h, η_c, η_ex and η_reg values. The maximum efficiencies have been found very close to the values corresponding to the maximum power density conditions but far from the values at maximum power. It has been found that the engines designed by considering the maximum power density have high efficiencies and small sizes under the same prescribed conditions. Copyright © 1999 John Wiley & Sons, Ltd.     

Improved Stirling engine performance through displacer surface treatment

This study intended to improve the performance of the beta‐type Stirling engine, being developed by the authors for solar energy and low‐grade heat sources, by means of displacer surface treatments. Three different displacers were manufactured and tested where one of them was without any surface treatment, other was zirconium coated with 0.15 mm thickness, and the other was helically knurled with 0.30 mm track depth. Because of good thermo‐physical properties, helium was used as the working fluid. The heat was supplied by an LPG burner. Tests were conducted at 360±10°C hot end temperature. The highest engine power was obtained with knurled displacer as 250 W at 545 rpm speed and corresponding to this power 4.38 Nm torque was obtained. This was followed by coated and smooth displacers. Power increments provided by the knurled displacer are 40 and 60% compared with the zirconium‐coated and untreated displacers. Increments of knurled displacer's torque compared with that of coated and untreated displacers are 13 and 30%, respectively. Copyright © 2009 John Wiley & Sons, Ltd.     

Simulation and experimental improvement on a small-scale Stirling thermo-acoustic engine

Compared with the traditional engines, the thermo-acoustic engines are relatively new and can act as the linear compressors for refrigerators. Many institutes have shown great interest in this kind of machine for its absence of moving mechanical part. In this paper, the influence of the dimensions of the main parts of the smallscale Stirling thermo-acoustic engine was numerically simulated using a computer code called DeltaEC. The resonator and the resonator cavity were found to be the most convenient and effective in improving the performance of the engine. Based on the numerical simulation, a small-scale Stirling thermo-acoustic engine were constructed and experimentally investigated. Currently, with a resonator length of only 1 m, the working frequency of the engine was decreased to 90 Hz and the onset temperature difference was decreased to 198.2 K.