A terrestrial solar thermal electric power system—Development of basic model system

A model system of a distributed collector power system was constructed at the Electrotechnical Laboratory, Tanashi, Tokyo, Japan in the summer of 1975. This model system consisted of a cylindrical parabolic concentrator, heat transfer loop and storage-type heat exchanger and has been used for evaluating the system performance and the dynamic characteristics of each subsystem and the whole system. This paper presents the performance of each subsystem used in the model system and summarizes results obtained from tests made on the whole system.     

碟式太阳能发电在分布式能源系统中的应用

碟式太阳能发电系统具有单机容量小,排布灵活,余热可综合利用等特点,是一种较适合与分布式能源系统结合的太阳能利用类型。对碟式太阳能发电技术进行逐一分析,总结了在分布式能源站中应用碟式太阳能所面临的诸多问题。结合实例,详细介绍华电电力科学研究院有限公司一套25 kW的碟式太阳能发电系统运行情况,提出系统的改进和提升方向。     

A new combined cooling, heating and power system driven by solar energy

A new combined cooling, heating and power (CCHP) system is proposed. This system is driven by solar energy, which is different from the current CCHP systems with gas turbine or engine as prime movers. This system combines a Rankine cycle and an ejector refrigeration cycle, which could produce cooling output, heating output and power output simultaneously. The effects of hour angle and the slope angle of the aperture plane for the solar collectors on the system performance are examined. Parametric optimization is conducted by means of genetic algorithm (GA) to find the maximum exergy efficiency. It is shown that the optimal slope angle of the aperture plane for the solar collectors is 60° at 10 a.m. on June 12, and the CCHP system can reach its optimal performance with the slope angle of 45° for the aperture plane at midday. It is also shown that the system can reach the maximum exergy efficiency of 60.33% under the conditions of the optimal slope angle and hour angle.     

Hybrid power generation system of solar energy and fuel cells

This paper introduces the methods of integration of solar energy and low‐temperature solid oxide fuel cells. On the one hand, we design the system that integrates the solar photovoltaic cells and fuel cells. On the other hand, solar energy is concentrated to heat up the fuel cell and supply the working temperature at hundreds Celsius degrees by Fresnel lens. Then the fuel conversion efficiency is increased because of gain from the solar energy. Moreover, integration of solar thermal energy power system with the fuel is a good method for resolving the instability of solar energy. CHP (combined heat and power) is another aspect to enhance the design hybrid system overall efficiency. Finally, we present a novel device but built on different scientific principle. It can convert solar energy and chemical energy of fuel to electric energy simultaneously within the same device to integrated solar cell and fuel cell from the device level. Copyright © 2016 John Wiley & Sons, Ltd.     

A solar energy storage and power generation system based on supercritical carbon dioxide

This paper proposes a new type of solar energy based power generation system using supercritical carbon dioxide and heat storage. The power generation cycle uses supercritical carbon dioxide as the working fluid and integrates the supercritical carbon dioxide cycle with an efficient high-temperature heat storage. The analysis shows that the new power generation system has significantly higher solar energy conversion efficiency in comparison to the conventional water-based (steam) system. At the same time, the heat storage not only overcomes the intermittent nature of solar energy but also improves the overall system efficiency. The study further reveals that the high temperatures and high pressures are favorable for solar energy storage and power generation. Moreover the expander and the heat storage/regenerator are found to be the key components that determine the overall system performance.     

A combined heat and power system for buildings driven by solar energy and gas

A novel hybrid solar/gas system intended to provide cooling/heating and electricity generation for buildings was developed. The system is based on the combination of an ejector heat pump cycle with a Rankine cycle. It is driven by solar energy and supplemented by a gas burner. The system also uses an environmentally friendly refrigerant to have minimal impact on the environment. Results of system computer modelling, prototype tests and economic analysis are reported. The system was judged to be viable and reliable. Technical improvements still have to be achieved to improve system economics.     

基于太阳能和朗肯循环的热电氢联供系统

随着世界各国对太阳能产业发展的日益重视,太阳能高效利用技术已成为新能源研究的热点.然而,由于太阳能具有间歇性、波动性及低能量密度等特点,造成太阳能在存储和利用过程中存在储能成本高、工艺复杂、整体利用率低等问题.太阳能发电与制氢技术的有机结合可将太阳能转化为氢气进行存储,实现能源间的高效转化与利用,可有效解决上述问题.本...     

A novel hybrid oxy-fuel power cycle utilizing solar thermal energy

An advanced oxy-fuel hybrid power system (AHPS) is proposed in this paper. Solar thermal energy is used in the AHPS to produce saturated steam as the working fluid, and natural gas is internally combusted with pure oxygen. It is in configuration close to the zero emission Graz cycle. The thermodynamic characteristics at design conditions of the AHPS are analyzed using the advanced process simulator Aspen Plus. The corresponding exergy loss analyses are also carried out to gain understanding of the loss distribution. The results are given in detail. The solar thermal hybrid H₂O turbine power generation system (STHS) is evaluated in this study as the reference. The comparison results demonstrate that the proposed cycle has notable advantages in thermodynamic performances. For example, the net fuel-to-electricity efficiency of the AHPS is 95.90%, which is 21.61 percentage points higher than that of the STHS. The exergy efficiency (based on the exergy input of fuel and solar thermal energy without radiation) of the AHPS is 55.88%, which is 2.13 percentage points higher than that of the STHS.     

Testing of a small-scale stand-alone power system based on solar energy and hydrogen

An experimental small-scale stand-alone power system based on hydrogen and solar energy has been tested. The system performance and operational experience are reported. Future expansion of the test-facility is taken into consideration using solutions with wide working ranges. The test-facility is designed for testing of individual components, for subsystems, and for complete power system operation. The complete power system in this study consists of a 4.8 kW programmable power supply, 1.5 kW electrolyser, a hydrogen purification unit (99.999% H₂ quality), a 14 Nm³ H₂ metal hydride storage, a 0.5 kW fuel cell, a 300 Ah lead-acid battery, and a 0.6 kW programmable load. Possible applications for such small-scale power systems are mountain cabins, remote islands, and telecommunication stations, among others. The basic idea in this particular power system configuration was to make it as simple as possible; the fuel cell and the metal hydride unit were air-cooled, and the components were connected in parallel without DC/DC converters. The only control action possible in the power system (presented in this study) was to switch the components either ON or OFF. However, connecting the components electrically in parallel without DC/DC converters gives no degrees of freedom regarding the ability to regulate power and voltage levels of the different components. Air-cooled metal hydrides might fail to deliver hydrogen due to poor heat transfer.     

太阳能与燃煤机组集成发电系统的研究现状

介绍了太阳能与燃煤机组集成发电系统的发展背景、国内外发展状况以及集成方式,对太阳能与回热系统集成等三种集成方式进行了比较,分析了几种提高集成发电系统经济性的优化方式,指出了发展中存在的一些问题及发展前景。     

Optimal solar energy collector system

The problem of designing solar energy collectors for the delivery of heat at minimum cost is analysed in two different forms. In the first of these, a set of collectors is assumed to be available, each element having different properties uniformly distributed over its area; an optimal design is achieved by a suitable combination of a subset of such collectors. In the second form the collector is designed with a non-uniform, continously varying insulation thickness. The principle of each solution is stated as a theorem. An example of the continuous solution for a flat plate collector is evaluated in the Appendix.     

Small hybrid solar power system

This paper introduces a novel concept of mini-hybrid solar power plant integrating a field of solar concentrators, two superposed Organic Rankine Cycles (ORC) and a (bio-)Diesel engine. The Organic Rankine Cycles include hermetic scroll expander-generators¹ and the sun tracking solar collectors are composed of rows of flat mirror bands (CEP) arranged in a plane, that focus the solar energy onto a collector tube similar to those used in SEGS plants in California. Waste heat from both the exhaust gases and the block cooling of the thermal engine are also heat sources for the ORCs. Such units meet electricity, cooling and pumping needs of remote settlements. The thermal engine guarantees a minimum level of both power and heat availability at night or during cloudy periods. Laboratory tests, made with the superposed ORCs only, confirmed adequate operational characteristics with good performances over a broad range of conditions. A few preliminary tests on the site of the solar power plant when coupled with the engine confirmed a reasonable behavior and the interest of the concept even at part load or during sharp variations of the thermal supply.     

风光互补独立供电系统优化匹配设计实例

以系统的最小安装成本为优化目标,以系统的供电可靠性为约束条件,对内蒙古满洲里市某居民家庭用电风光互补独立供电系统进行基于计算机仿真计算的优化匹配设计。     

Simultaneous desalination and power generation using solar energy

Using solar energy to produce fresh water and electricity simultaneously is a prospective way to solve the problems combining fresh water shortage, energy crisis and farm land degradation in Northern Victoria. This paper records the process of calculating the performance of the nozzle applying homogenous equilibrium model, designing and testing the prototype of such system using three different types of the nozzles in static and rotary systems. The research on the project is divided into two steps: first is about static system in which the spray nozzle is proved to be the best in both production of fresh water and power generation; while on the second stage, the convergent–divergent (C–D) nozzles are the best in rotary system. Some data were analyzed theoretically based on the test and the results found that the percentage of fresh water measured by experiment is consistent with the calculation using homogenous equilibrium expansion model (HEM), however, there is big difference in power generation between theory and experiments. Based on our experimental figures and analysis, the reasons for low power generation are found and a new model is proposed. According to the new model, a different reaction turbine using curve length C–D nozzles is designed to overcome the problems which were encountered in the previous prototype. After analyzing the efficiency of the cycle by T–s diagram, the evacuated tube solar collector integrated heat pipe is suggested to be applied on this system.     

Thermal-photovoltaic solar hybrid system for efficient solar energy conversion

A hybrid solar system with high temperature stage is described. The system contains a radiation concentrator, a photovoltaic solar cell and a heat engine or thermoelectric generator. Two options are discussed, one with a special PV cell construction, which uses the heat energy from the part of solar spectrum not absorbed in the semiconductor material of the cell; the other with concentration of the whole solar radiation on the PV cell working at high temperature and coupled to the high temperature stage. The possibilities of using semiconductor materials with different band gap values are analyzed, as well as of the different thermoelectric materials. The calculations made show that the proposed hybrid system could be practical and efficient.     

A novel maximum power fuzzy logic controller for photovoltaic solar energy systems

The maximum power tracking problem and efficient energy utilization of a stand-alone photovoltaic array (PVA) feeding voltage controlled linear and nonlinear loads is studied. A novel and simple on-line fuzzy logic-based dynamic search, detection and tracking controller is developed to ensure maximum power point (MPP) operation under excursions in solar insolation, ambient temperature and electric load variations. A computer simulation model of the PVA renewable utilization scheme including the effects of temperature and solar irradiation changes was developed and fully simulated. The load voltage is controlled by a DC chopper and kept constant at the required rated voltage. A permanent magnet DC motor (PMDC) driving a fan-type load was connected in parallel to an RL passive load. A speed control scheme is also used for the PMDC motor drive so that the drive can be operated at specified speeds. Different controllers have been employed in the unified PVA scheme to control three separate loads at MPP tracking condition namely voltage at load bus and speed of the PMDC motor. The main objective of the paper is to present a novel enhanced, cost-effective MPP detector (MPPD) and dynamic MPP tracking (MPPT) controller for a hybrid mix of electric loads.     

A random walk approximation for a solar energy storage system

A solar energy storage system is modelled as a reservoir model with input and output conversion efficiency factors. Using Wald's Identity, an approximation is obtained for the steady-state distribution of the energy storage level and the steady-state expected value of the energy storage level.     

A medium-temperature solar thermal power system and its efficiency optimisation

This paper firstly expounds that the reheat-regenerative Rankine power cycle is a suitable cycle for the parabolic trough collector, a popular kind of collector in the power industry. In a thermal power cycle, the higher the temperature at which heat is supplied, the higher the efficiency of the cycle. On the other hand, for a given kind of collector at the same exiting temperature, the higher the temperature of the fluid entering the collector, the lower the efficiency of the collector. With the same exiting temperature of the solar field and the same temperature differences at the hottest end of the superheater/reheater and at the pinch points in the heat exchangers (e.g., the boiler) in the cycle, the efficiencies of the system are subject to the temperature of the fluid entering the collector or the saturation temperature at the boiler. This paper also investigates the optimal thermal and exergetic efficiencies for the combined system of the power cycle and collector. To make most advantage of the collector, the exiting fluid is supposed to be at the maximum temperature the collector can harvest. Hence, the thermal and exergetic efficiencies of the system are related to the saturation temperature at the boiler here.     

太阳能空调热水系统研究分析

前言日益普及并呈加速发展的室内空气调节 ,需要消耗大量电能和化石燃料。常规空调制冷剂ＣＦＣｓ 对大气臭氧层有破坏作用 ,影响环境。因此 ,在空调制冷技术的发展与应用中 ,面临着节电、节能和环保三大问题。当前不用氟氯烃作工质、热驱动的吸收式制冷 ,日益受到人们的重视。太阳能是取之不尽 ,用之不竭 ,可再生的清洁能源。太阳能热水器现已发展到非常成熟的水平 ,它是以获取生活热水为目的的。但这种应用方式与人们的生活需求正相反 ,当夏季太阳辐射强、气温高的时候 ,太阳能热水器产生的热水量最大 ,而此时最需要的是空调降温而不是热…     

A satellite-based solar energy monitoring system for tasmania, Australia

Visible reflectivity data from the Japanese Meteorological Satellite are used to estimate the daily global radiation in Tasmania, Australia. Data are accessed from the national facsimile network, which provides satellite images for routine meteorological forecasts. This retrieval technique is economical and provides nearly real-time data over the entire state. The main limitation is that logistic problems in the facsimile network do not allow all images to be retrieved. A simple linear relation is presented that uses satellite reflectivity data to estimate daily and monthly global radiation. Mean daily global radiation for the state during August and December 1983 are presented.