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.     

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。     

国内首座碟式太阳能斯特林光热示范电厂落户鄂尔多斯

2012年7月底,大连宏海新能源发展有限公司与瑞典Cleanergy公司合作完成的华原集团100kW碟式太阳能光热示范电厂在内蒙古鄂尔多斯市成功安装,并完成了联合调试,进入试运行阶段。这也是国内第一个应用碟式太阳能斯特林技术进行发电的光热示范电厂。     

基子多孔介质燃烧器的煤层气斯特林发动机发电系统

提出一种新的煤层气发电方式，即多孔介质燃烧器驱动斯特林发动机系统。将斯特林发动机的外燃特性和多孔介质燃烧器对气源不稳定性的良好适应能力有机结合，初步构建适应煤层气气源不稳定性的煤层气发电系统。     

斯特林发动机在钠冷快堆核电源上的应用控制策略

针对钠冷快堆液钠供热与斯特林发动机做功之间的时间迟滞问题,以及运行中的管壁温度不低于250 ℃、出口液钠温度不高于420 ℃的控制要求,通过分析斯特林发动机控制模型,提出在启动时采用分段速过渡过程控制策略。在运行发电时先建立钠冷快堆液钠流量与斯特林发动机工质压力关系识别控制模型,进一步使用微分提前补偿控制策略;在停车时先降低斯特林发动机转速,采用定时定量策略控制斯特林发动机工质压力后再进一步控制转速降低至零。试验结果表明,控制策略方法可实现钠冷快堆核电源斯特林发动机热电转换模块的安全运行,且发电效率达到24.5%,与理论值基本一致,该控制策略具有一定的实用性,有利于斯特林发动机在核能领域的推广使用。     

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。     

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。     

深空探测用斯特林发电器的发展

自由活塞斯特林循环动态发电技术具有效率高、寿命长、结构紧凑等诸多特点,目前受到深空探测电源系统的高度重视。随着影响发电器性能的各种关键技术逐步得到解决,斯特林发电器各方面性能已经有了很大提高,航天大国已经此项技术列为应用计划。主要介绍了国外空间斯特林发电器的发展历程、关键技术,为国内开展这方面工作提供有益参考。     

太阳能热发电——太阳能斯特林热发电

本文通过对太阳能热发电,特别是太阳能斯特林热发电的发展和特点进行了叙述,说明了发展太阳能斯特林发电技术的意义和重要性.     

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.     

Analysis and design consideration of mean temperature differential Stirling engine for solar application

This article presents a technical innovation, study of solar power system based on the Stirling dish (SD) technology and design considerations to be taken in designing of a mean temperature differential Stirling engine for solar application. The target power source will be solar dish/Stirling with average concentration ratio, which will supply a constant source temperature of 320 °C. Hence, the system design is based on a temperature difference of 300 °C, assuming that the sink is kept at 20 °C. During the preliminary design stage, the critical parameters of the engine design are determined according to the dynamic model with losses energy and pressure drop in heat exchangers was used during the design optimisation stage in order to establish a complete analytical model for the engine. The heat exchangers are designed to be of high effectiveness and low pressure-drop. Upon optimisation, for given value of difference temperature, operating frequency and dead volume there is a definite optimal value of swept volume at which the power is a maximum. The optimal swept volume of 75 cm³ for operating frequency 75 Hz with the power is 250 W and the dead volume is of 370 cm³.     

Optimization of Output Power and Thermal Efficiency of Solar‐Dish Stirling Engine Using Finite Time Thermodynamic Analysis

This paper presents an investigation on finite time thermodynamic (FTT) evaluation of a solar‐dish Stirling heat engine. FTTs has been applied to determine the output power and the corresponding thermal efficiency, exergetic efficiency, and the rate of entropy generation of a solar Stirling system with a finite rate of heat transfer, regenerative heat loss, conductive thermal bridging loss, and finite regeneration process time. Further imperfect performance of the dish collector and convective/radiative heat transfer mechanisms in the hot end as well as the convective heat transfer in the heat sink of the engine are considered in the developed model. The output power of the engine is maximized while the highest temperature of the engine is considered as a design parameter. In addition, thermal efficiency, exergetic efficiency, and the rate of entropy generation corresponding to the optimum value of the output power is evaluated. Results imply that the optimized absorber temperature is some where between 850 K and 1000 K. Sensitivity of results against variations of the system parameters are studied in detail. The present analysis provides a good theoretical guidance for the designing of dish collectors and operating the Stirling heat engine system.     

聚光太阳能发电技术应用与前景

分析了聚光太阳能发电三大技术（线性聚光系统、碟/引擎系统、电力塔系统）以及热能储存系统,阐述了其结构、工作原理与研究方向,比较了这三大技术之间的经济技术性能,介绍了适合我国太阳能辐射量大的边远地区碟/引擎系统的应用,展示了太阳能热发电技术的应用前景及对节能减排的贡献。     

Technical and economical evaluation of solar thermal power generation

This article presents a feasibilty on a solar power system based on the Stirling dish (SD) technology, reviews and compares the available Stirling engines in the perspective of a solar Stirling system.The system is evaluated, as a parameter to alleviate the energy system of the Cretan island while taking care of the CO₂ emissions. In the results a sensitivity analysis was implemented, as well as a comparison with conventional power systems.In the long-term, solar thermal power stations based on a SD can become a competitive option on the electricity market, if a concerted programme capable of building the forces of industry, finance, insurance and other decision makers will support the market extension for this promising technology.     

Multi-objective optimization for GPU3 Stirling engine by combining multi-objective algorithms

Stirling engine has become preferable for high attention towards the use of alternate renewable energy resources like biomass and solar energy. Stirling engine is the main component of dish Stirling system in thermal power generation sector. Stirling engine is an externally heating engine, which theoretical efficiency is as high as Carnot cycle's, but actual ones are always far below compared with the Carnot efficiency. A number of studies have been done on multi-objective optimization to improve the design of Stirling engine. In the current study, a multi-objective optimization method, which is a combination of multiple optimization algorithms including differential evolution, genetic algorithm and adaptive simulated annealing, was proposed. This method is an attempt to generalize and improve the robustness and diversity with above three kinds of population based meta-heuristic optimization techniques. The analogous interpreter was linked and interchanged to find the best global optimal solution for Stirling engine performance optimization. It decreases the chance of convergence at a local minimum by powering from the fact that these three algorithms run parallel and members from each population and technique are swapped. The optimization considers five decision variables, including engine frequency, mean effective pressure, temperature of heating source, number of wires in regenerator matrix, and the wire diameter of regenerator, as multiple objectives. The Pareto optimal frontier was obtained and a final optimal solution was also selected by using various multi-criteria decision making methods including techniques for Order of Preference by Similarity to Ideal Solution and Simple Additive Weighting. The multi-objective optimization indicated a way for GPU-3 Stirling engine to obtain an output power of more than 3 kW and an increase by 5% in thermal efficiency with significant decrease in power loss due to flow resistance.     

Techno-economic appraisal of a dish/stirling solar power plant in Greece based on an innovative solar concentrator formed by elastic film

As the environmental problems caused by the use of conventional fuels have risen significantly and due to the increase in fossil fuel prices, the importance of reducing society dependence on non-renewable energy sources becomes more and more urgent. It is clear that this could only happen by switching to extensive use of clean energy sources such as renewable energy sources. In this paper a technical feasibility and economic viability study of a dish/Stirling solar power plant in Greece is presented. The proposed power plant uses Dish/Stirling technology and has nominal power 10 MW. The proposed solar concentrator system consists of a primary mirror, formed by elastic film, used to focus the sun's rays onto a secondary mirror which then deviates this radiation into the receiver (Stirling engine). TRNSYS program was developed to simulate Dish/Stirling power plant operation in order to investigate its performance in Greece. The simulation predicted that the proposed power plant could produce 11.19 GWh annually. Project investment cost is approximately 27,000,000 €, while payback is achieved after 16 years of operation. The total profit at the end of the analysis period of 25 years is estimated to be 25,500,000 €.     

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.